ART 3.5D: an algorithm to label arteries and veins from three-dimensional angiography.

PubMed

Barra, Beatrice; De Momi, Elena; Ferrigno, Giancarlo; Pero, Guglielmo; Cardinale, Francesco; Baselli, Giuseppe

2016-10-01

Preoperative three-dimensional (3-D) visualization of brain vasculature by digital subtraction angiography from computerized tomography (CT) in neurosurgery is gaining more and more importance, since vessels are the primary landmarks both for organs at risk and for navigation. Surgical embolization of cerebral aneurysms and arteriovenous malformations, epilepsy surgery, and stereoelectroencephalography are a few examples. Contrast-enhanced cone-beam computed tomography (CE-CBCT) represents a powerful facility, since it is capable of acquiring images in the operation room, shortly before surgery. However, standard 3-D reconstructions do not provide a direct distinction between arteries and veins, which is of utmost importance and is left to the surgeon's inference so far. Pioneering attempts by true four-dimensional (4-D) CT perfusion scans were already described, though at the expense of longer acquisition protocols, higher dosages, and sensible resolution losses. Hence, space is open to approaches attempting to recover the contrast dynamics from standard CE-CBCT, on the basis of anomalies overlooked in the standard 3-D approach. This paper aims at presenting algebraic reconstruction technique (ART) 3.5D, a method that overcomes the clinical limitations of 4-D CT, from standard 3-D CE-CBCT scans. The strategy works on the 3-D angiography, previously segmented in the standard way, and reprocesses the dynamics hidden in the raw data to recover an approximate dynamics in each segmented voxel. Next, a classification algorithm labels the angiographic voxels and artery or vein. Numerical simulations were performed on a digital phantom of a simplified 3-D vasculature with contrast transit. CE-CBCT projections were simulated and used for ART 3.5D testing. We achieved up to 90% classification accuracy in simulations, proving the feasibility of the presented approach for dynamic information recovery for arteries and veins segmentation.

3D time-lapse analysis of Rab11/FIP5 complex: spatiotemporal dynamics during apical lumen formation.

PubMed

Mangan, Anthony; Prekeris, Rytis

2015-01-01

Fluorescent imaging of fixed cells grown in two-dimensional (2D) cultures is one of the most widely used techniques for observing protein localization and distribution within cells. Although this technique can also be applied to polarized epithelial cells that form three-dimensional (3D) cysts when grown in a Matrigel matrix suspension, there are still significant limitations in imaging cells fixed at a particular point in time. Here, we describe the use of 3D time-lapse imaging of live cells to observe the dynamics of apical membrane initiation site (AMIS) formation and lumen expansion in polarized epithelial cells.

Encrypted Three-dimensional Dynamic Imaging using Snapshot Time-of-flight Compressed Ultrafast Photography

PubMed Central

Liang, Jinyang; Gao, Liang; Hai, Pengfei; Li, Chiye; Wang, Lihong V.

2015-01-01

Compressed ultrafast photography (CUP), a computational imaging technique, is synchronized with short-pulsed laser illumination to enable dynamic three-dimensional (3D) imaging. By leveraging the time-of-flight (ToF) information of pulsed light backscattered by the object, ToF-CUP can reconstruct a volumetric image from a single camera snapshot. In addition, the approach unites the encryption of depth data with the compressed acquisition of 3D data in a single snapshot measurement, thereby allowing efficient and secure data storage and transmission. We demonstrated high-speed 3D videography of moving objects at up to 75 volumes per second. The ToF-CUP camera was applied to track the 3D position of a live comet goldfish. We have also imaged a moving object obscured by a scattering medium. PMID:26503834

Fast and background-free three-dimensional (3D) live-cell imaging with lanthanide-doped upconverting nanoparticles.

PubMed

Jo, Hong Li; Song, Yo Han; Park, Jinho; Jo, Eun-Jung; Goh, Yeongchang; Shin, Kyujin; Kim, Min-Gon; Lee, Kang Taek

2015-12-14

We report on the development of a three-dimensional (3D) live-cell imaging technique with high spatiotemporal resolution using lanthanide-doped upconverting nanoparticles (UCNPs). It employs the sectioning capability of confocal microscopy except that the two-dimensional (2D) section images are acquired by wide-field epi-fluorescence microscopy. Although epi-fluorescence images are contaminated with the out-of-focus background in general, the near-infrared (NIR) excitation used for the excitation of UCNPs does not generate any autofluorescence, which helps to lower the background. Moreover, the image blurring due to defocusing was naturally eliminated in the image reconstruction process. The 3D images were used to investigate the cellular dynamics such as nuclear uptake and single-particle tracking that require 3D description.

How Spatial Abilities and Dynamic Visualizations Interplay When Learning Functional Anatomy with 3D Anatomical Models

ERIC Educational Resources Information Center

Berney, Sandra; Bétrancourt, Mireille; Molinari, Gaëlle; Hoyek, Nady

2015-01-01

The emergence of dynamic visualizations of three-dimensional (3D) models in anatomy curricula may be an adequate solution for spatial difficulties encountered with traditional static learning, as they provide direct visualization of change throughout the viewpoints. However, little research has explored the interplay between learning material…

BEST3D user's manual: Boundary Element Solution Technology, 3-Dimensional Version 3.0

NASA Technical Reports Server (NTRS)

1991-01-01

The theoretical basis and programming strategy utilized in the construction of the computer program BEST3D (boundary element solution technology - three dimensional) and detailed input instructions are provided for the use of the program. An extensive set of test cases and sample problems is included in the manual and is also available for distribution with the program. The BEST3D program was developed under the 3-D Inelastic Analysis Methods for Hot Section Components contract (NAS3-23697). The overall objective of this program was the development of new computer programs allowing more accurate and efficient three-dimensional thermal and stress analysis of hot section components, i.e., combustor liners, turbine blades, and turbine vanes. The BEST3D program allows both linear and nonlinear analysis of static and quasi-static elastic problems and transient dynamic analysis for elastic problems. Calculation of elastic natural frequencies and mode shapes is also provided.

Holographic three-dimensional telepresence using large-area photorefractive polymer.

PubMed

Blanche, P-A; Bablumian, A; Voorakaranam, R; Christenson, C; Lin, W; Gu, T; Flores, D; Wang, P; Hsieh, W-Y; Kathaperumal, M; Rachwal, B; Siddiqui, O; Thomas, J; Norwood, R A; Yamamoto, M; Peyghambarian, N

2010-11-04

Holography is a technique that is used to display objects or scenes in three dimensions. Such three-dimensional (3D) images, or holograms, can be seen with the unassisted eye and are very similar to how humans see the actual environment surrounding them. The concept of 3D telepresence, a real-time dynamic hologram depicting a scene occurring in a different location, has attracted considerable public interest since it was depicted in the original Star Wars film in 1977. However, the lack of sufficient computational power to produce realistic computer-generated holograms and the absence of large-area and dynamically updatable holographic recording media have prevented realization of the concept. Here we use a holographic stereographic technique and a photorefractive polymer material as the recording medium to demonstrate a holographic display that can refresh images every two seconds. A 50 Hz nanosecond pulsed laser is used to write the holographic pixels. Multicoloured holographic 3D images are produced by using angular multiplexing, and the full parallax display employs spatial multiplexing. 3D telepresence is demonstrated by taking multiple images from one location and transmitting the information via Ethernet to another location where the hologram is printed with the quasi-real-time dynamic 3D display. Further improvements could bring applications in telemedicine, prototyping, advertising, updatable 3D maps and entertainment.

Effects of spatial curvature and anisotropy on the asymptotic regimes in Einstein-Gauss-Bonnet gravity

NASA Astrophysics Data System (ADS)

Pavluchenko, Sergey A.; Toporensky, Alexey

2018-05-01

In this paper we address two important issues which could affect reaching the exponential and Kasner asymptotes in Einstein-Gauss-Bonnet cosmologies—spatial curvature and anisotropy in both three- and extra-dimensional subspaces. In the first part of the paper we consider the cosmological evolution of spaces that are the product of two isotropic and spatially curved subspaces. It is demonstrated that the dynamics in D=2 (the number of extra dimensions) and D ≥ 3 is different. It was already known that for the Λ -term case there is a regime with "stabilization" of extra dimensions, where the expansion rate of the three-dimensional subspace as well as the scale factor (the "size") associated with extra dimensions reaches a constant value. This regime is achieved if the curvature of the extra dimensions is negative. We demonstrate that it takes place only if the number of extra dimensions is D ≥ 3. In the second part of the paper we study the influence of the initial anisotropy. Our study reveals that the transition from Gauss-Bonnet Kasner regime to anisotropic exponential expansion (with three expanding and contracting extra dimensions) is stable with respect to breaking the symmetry within both three- and extra-dimensional subspaces. However, the details of the dynamics in D=2 and D ≥ 3 are different. Combining the two described effects allows us to construct a scenario in D ≥ 3, where isotropization of outer and inner subspaces is reached dynamically from rather general anisotropic initial conditions.

Biodynamic imaging for phenotypic profiling of three-dimensional tissue culture

PubMed Central

Sun, Hao; Merrill, Daniel; An, Ran; Turek, John; Matei, Daniela; Nolte, David D.

2017-01-01

Abstract. Three-dimensional (3-D) tissue culture represents a more biologically relevant environment for testing new drugs compared to conventional two-dimensional cancer cell culture models. Biodynamic imaging is a high-content 3-D optical imaging technology based on low-coherence interferometry and digital holography that uses dynamic speckle as high-content image contrast to probe deep inside 3-D tissue. Speckle contrast is shown to be a scaling function of the acquisition time relative to the persistence time of intracellular transport and hence provides a measure of cellular activity. Cellular responses of 3-D multicellular spheroids to paclitaxel are compared among three different growth techniques: rotating bioreactor (BR), hanging-drop (HD), and nonadherent (U-bottom, UB) plate spheroids, compared with ex vivo living tissues. HD spheroids have the most homogeneous tissue, whereas BR spheroids display large sample-to-sample variability as well as spatial heterogeneity. The responses of BR-grown tumor spheroids to paclitaxel are more similar to those of ex vivo biopsies than the responses of spheroids grown using HD or plate methods. The rate of mitosis inhibition by application of taxol is measured through tissue dynamics spectroscopic imaging, demonstrating the ability to monitor antimitotic chemotherapy. These results illustrate the potential use of low-coherence digital holography for 3-D pharmaceutical screening applications. PMID:28301634

Biodynamic imaging for phenotypic profiling of three-dimensional tissue culture

NASA Astrophysics Data System (ADS)

Sun, Hao; Merrill, Daniel; An, Ran; Turek, John; Matei, Daniela; Nolte, David D.

2017-01-01

Three-dimensional (3-D) tissue culture represents a more biologically relevant environment for testing new drugs compared to conventional two-dimensional cancer cell culture models. Biodynamic imaging is a high-content 3-D optical imaging technology based on low-coherence interferometry and digital holography that uses dynamic speckle as high-content image contrast to probe deep inside 3-D tissue. Speckle contrast is shown to be a scaling function of the acquisition time relative to the persistence time of intracellular transport and hence provides a measure of cellular activity. Cellular responses of 3-D multicellular spheroids to paclitaxel are compared among three different growth techniques: rotating bioreactor (BR), hanging-drop (HD), and nonadherent (U-bottom, UB) plate spheroids, compared with ex vivo living tissues. HD spheroids have the most homogeneous tissue, whereas BR spheroids display large sample-to-sample variability as well as spatial heterogeneity. The responses of BR-grown tumor spheroids to paclitaxel are more similar to those of ex vivo biopsies than the responses of spheroids grown using HD or plate methods. The rate of mitosis inhibition by application of taxol is measured through tissue dynamics spectroscopic imaging, demonstrating the ability to monitor antimitotic chemotherapy. These results illustrate the potential use of low-coherence digital holography for 3-D pharmaceutical screening applications.

Three-dimensional aerodynamic shape optimization of supersonic delta wings

NASA Technical Reports Server (NTRS)

Burgreen, Greg W.; Baysal, Oktay

1994-01-01

A recently developed three-dimensional aerodynamic shape optimization procedure AeSOP(sub 3D) is described. This procedure incorporates some of the most promising concepts from the area of computational aerodynamic analysis and design, specifically, discrete sensitivity analysis, a fully implicit 3D Computational Fluid Dynamics (CFD) methodology, and 3D Bezier-Bernstein surface parameterizations. The new procedure is demonstrated in the preliminary design of supersonic delta wings. Starting from a symmetric clipped delta wing geometry, a Mach 1.62 asymmetric delta wing and two Mach 1. 5 cranked delta wings were designed subject to various aerodynamic and geometric constraints.

Vehicle dynamics control by using a three-dimensional stabilizer pendulum system

NASA Astrophysics Data System (ADS)

Goodarzi, A.; Naghibian, M.; Choodan, D.; Khajepour, A.

2016-12-01

Active safety systems of a vehicle normally work well on tyre-road interactions, however, these systems deteriorate in performance on low-friction road conditions. To combat this effect, an innovative idea for the yaw moment and roll dynamic control is presented in this paper. This idea was inspired by the chase and run dynamics animals like cheetahs in the nature; cheetahs have the ability to swerve while running at very high speeds. A cheetah controls its dynamics by rotating its long tail. A three-dimensional stabilizer pendulum system (3D-SPS) resembles the rotational motion of the tail of a cheetah to improve the stability and safety of a vehicle. The idea has been developed in a stand-alone 3D stabilizer pendulum system as well as in an integrated control system, which consists of an ordinary differential braking direct yaw control (DYC) and active steering control that is assisted by the 3D-SPS. The performance of the proposed 3D-SPS has been evaluated over a wide range of handling manoeuvres by using a comprehensive numerical simulation. The results show the advantage of 3D-SPS over conventional control approaches, which are ineffective on low-friction road conditions and high lateral acceleration manoeuvres. It should however be noted that the best vehicle dynamics performance is obtained when an integrated 3D-SPS and DYC and AFS is utilised.

Liquid/vapor-induced reversible dynamic structural transformation of a three-dimensional Cu-based MOF to a one-dimensional MOF showing gate adsorption.

PubMed

Kondo, Atsushi; Suzuki, Takayuki; Kotani, Ryosuke; Maeda, Kazuyuki

2017-05-23

A new 3D metal-organic framework (MOF), in which 2D layers are interlaced to form a 3D architecture, was synthesized by a reaction of Cu(BF 4 ) 2 and 1,3-bis(4-pyridyl)propane (bpp) in a water/1-hexanol solvent system, and the crystal structure of the MOF was successfully solved. The MOF is reversibly transformed to a 1D chain MOF, which shows gate adsorption properties. The dynamic transformation gives crystal size reduction resulting in a slight change in CO 2 adsorption isotherms. The 1D MOF shows selective adsorption/separation properties on benzene and its analogues with similar sizes and shapes (benzene, toluene, and cyclohexane).

Numerical, analytical, experimental study of fluid dynamic forces in seals

NASA Technical Reports Server (NTRS)

Shapiro, William; Artiles, Antonio; Aggarwal, Bharat; Walowit, Jed; Athavale, Mahesh M.; Preskwas, Andrzej J.

1992-01-01

NASA/Lewis Research Center is sponsoring a program for providing computer codes for analyzing and designing turbomachinery seals for future aerospace and engine systems. The program is made up of three principal components: (1) the development of advanced three dimensional (3-D) computational fluid dynamics codes, (2) the production of simpler two dimensional (2-D) industrial codes, and (3) the development of a knowledge based system (KBS) that contains an expert system to assist in seal selection and design. The first task has been to concentrate on cylindrical geometries with straight, tapered, and stepped bores. Improvements have been made by adoption of a colocated grid formulation, incorporation of higher order, time accurate schemes for transient analysis and high order discretization schemes for spatial derivatives. This report describes the mathematical formulations and presents a variety of 2-D results, including labyrinth and brush seal flows. Extensions of 3-D are presently in progress.

Faulting of Rocks in a Three-Dimensional Stress Field by Micro-Anticracks

PubMed Central

Ghaffari, H. O.; Nasseri, M. H. B.; Young, R. Paul

2014-01-01

Nucleation and propagation of a shear fault is known to be the result of interaction and coalescence of many microcracks. Yet the character and rate of the microcracks' interactions, and their dependence on the three-dimensional stress state are poorly understood. Here we investigate formation of microcracks during sandstone faulting under 3D-polyaxial stress fields by analyzing multi-stationary acoustic waveforms. We show that in a true three-dimensional stress state (a) faulting forms in a orthorhombic pattern, and (b) the emitted acoustic waveforms from microcracking carry a shorter rapid slip phase. The later is associated with microcracking that dominantly develops parallel to the minimum stress direction. Our results imply that due to inducing the micro-anticracks, the three-dimensional (3D) stress state can quicken dynamic weakening and rupture propagation by a factor of two relatively to simpler stress states. The results suggest a new nucleation mechanism of 3D-faulting with implications for earthquakes' instabilities, as well as the understanding of avalanches associated with dislocations. PMID:24862447

The boundary element method applied to 3D magneto-electro-elastic dynamic problems

NASA Astrophysics Data System (ADS)

Igumnov, L. A.; Markov, I. P.; Kuznetsov, Iu A.

2017-11-01

Due to the coupling properties, the magneto-electro-elastic materials possess a wide number of applications. They exhibit general anisotropic behaviour. Three-dimensional transient analyses of magneto-electro-elastic solids can hardly be found in the literature. 3D direct boundary element formulation based on the weakly-singular boundary integral equations in Laplace domain is presented in this work for solving dynamic linear magneto-electro-elastic problems. Integral expressions of the three-dimensional fundamental solutions are employed. Spatial discretization is based on a collocation method with mixed boundary elements. Convolution quadrature method is used as a numerical inverse Laplace transform scheme to obtain time domain solutions. Numerical examples are provided to illustrate the capability of the proposed approach to treat highly dynamic problems.

Advantages of T2 Weighted Three Dimensional and T1 Weighted Three Dimensional Contrast Medium Enhanced Magnetic Resonance Urography in Examination of the Child Population.

PubMed

Sehic, Adnan; Julardzija, Fuad; Vegar-Zubovic, Sandra; Sefic-Pasic, Irmina

2017-03-01

The aim of this study is to prove the advantages of combined use of T2 weighted three dimensional (T2 W 3D) and T1 weighted three dimensional contrast medium enhanced (T1 W 3D CE) magnetic resonance (MR) urography in displaying urinary tract in child population. Total of 120 patients were included in the study, 71 (59%) male patients and 49 (41%) female patients. The study was conducted on the Radiology clinic, University of Sarajevo Clinical Center, during the period from February to November 2016. Patients were examined on the 1.5T and 3T MRI, with standard protocol which includes T2 W 3D and T1 W 3D contrast medium enhanced MR urography. In the post procesing quantitative measurement of signal intensity and evaluation of the display quality in the area of renal pelvis, middle of ureter and the mouth of the ureter were done. Measurement was concluded on Syngo software B13. Analyzing the acquired data and statistically processing them we got results which have shown higher signal intensity of measured structures on T1 W 3D contrast medium enhanced MR urography on the level p<0.01 and p<0.05 compared to T2 W 3D MR urography in patients that had normal dynamics of contrast medium secretion. However, in kidneys with decreased function, T2 W 3D MR urography provided higher signal intensity and better display compared to T1 W 3D contrast medium enhanced MR urography on the level p<0.05 and p<0.01. T2 W3D MR urography is useful in imaging nonfunctional kidney as well as in patients prone to allergic reactions, where as T1 W3D CE MR urography is at an advantage over T2 W 3D MR urography in imaging the kidney functionality, kidney dynamics measurement, it provides higher MRI signal intensity required for clear 3D reconstructions.

Three-dimensional imaging of dislocation dynamics during the hydriding phase transformation

DOE PAGES

Ulvestad, A.; Welland, M. J.; Cha, W.; ...

2017-01-16

Crystallographic imperfections can significantly alter material properties and responses to external stimuli, including solute induced phase transformations and crystal growth and dissolution . Despite recent progress in imaging defects using both electron and x-ray techniques, in situ three-dimensional imaging studies of defect dynamics, necessary to understand and engineer nanoscale processes, remains challenging. Here, we report in situ three-dimensional imaging of defect dynamics during the hydriding phase transformation of individual palladium nanocrystals by Bragg Coherent Diffractive Imaging (BCDI) . During constant pressure experiments, we observed that the phase transformation begins after the nucleation of dislocations in large (300 nm) particles. Themore » 3D dislocation network shows that dislocations are close to the phase boundary. The 3D phase morphology resolved by BCDI suggests that the hydrogen-rich phase is more similar to a spherical cap on the hydrogen-poor phase than the core-shell model commonly assumed. We substantiate this conclusion using 3D phase field modeling and demonstrate how phase morphology affects the critical size for dislocation nucleation. We determine the size dependence of the transformation pressure for large (150-300 nm) palladium nanocrystals using variable pressure experiments. Our results reveal a pathway for solute induced structural phase transformations in nanocrystals and demonstrate BCDI as a novel method for understanding dislocation dynamics in phase transforming systems at the nanoscale.« less

Exact results in 3d N = 2 Spin(7) gauge theories with vector and spinor matters

NASA Astrophysics Data System (ADS)

Nii, Keita

2018-05-01

We study three-dimensional N = 2 Spin(7) gauge theories with N S spinorial matters and with N f vectorial matters. The quantum Coulomb branch on the moduli space of vacua is one- or two-dimensional depending on the matter contents. For particular values of ( N f , N S ), we find s-confinement phases and derive exact superpotentials. The 3d dynamics of Spin(7) is connected to the 4d dynamics via KK-monopoles. Along the Higgs branch of the Spin(7) theories, we obtain 3d N = 2 G 2 or SU(4) theories and some of them lead to new s-confinement phases. As a check of our analysis we compute superconformal indices for these theories.

Improved Design of Tunnel Supports : Volume 3 : Finite Element Analysis of the Peachtree Center Station in Atlanta

DOT National Transportation Integrated Search

1980-06-01

Volume 3 contains the application of the three-dimensional (3-D) finite element program, Automatic Dynamic Incremental Nonlinear Analysis (ADINA), which was designed to replace the traditional 2-D plane strain analysis, to a specific location. The lo...

Dynamic characteristics of a pump-turbine during hydraulic transients of a model pumped-storage system: 3D CFD simulation

NASA Astrophysics Data System (ADS)

Zhang, X. X.; Cheng, Y. G.; Xia, L. S.; Yang, J. D.

2014-03-01

The runaway process in a model pumped-storage system was simulated for analyzing the dynamic characteristics of a pump-turbine. The simulation was adopted by coupling 1D (One Dimensional) pipeline MOC (Method of Characteristics) equations with a 3D (Three Dimensional) pump-turbine CFD (Computational Fluid Dynamics) model, in which the water hammer wave in the 3D zone was defined by giving a pressure dependent density. We found from the results that the dynamic performances of the pump-turbine do not coincide with the static operating points, especially in the S-shaped characteristics region, where the dynamic trajectories follow ring-shaped curves. Specifically, the transient operating points with the same Q11 and M11 in different moving directions of the dynamic trajectories give different n11. The main reason of this phenomenon is that the transient flow patterns inside the pump-turbine are influenced by the ones in the previous time step, which leads to different flow patterns between the points with the same Q11 and M11 in different moving directions of the dynamic trajectories.

Super-resolution three-dimensional fluorescence and optical diffraction tomography of live cells using structured illumination generated by a digital micromirror device.

PubMed

Shin, Seungwoo; Kim, Doyeon; Kim, Kyoohyun; Park, YongKeun

2018-06-15

We present a multimodal approach for measuring the three-dimensional (3D) refractive index (RI) and fluorescence distributions of live cells by combining optical diffraction tomography (ODT) and 3D structured illumination microscopy (SIM). A digital micromirror device is utilized to generate structured illumination patterns for both ODT and SIM, which enables fast and stable measurements. To verify its feasibility and applicability, the proposed method is used to measure the 3D RI distribution and 3D fluorescence image of various samples, including a cluster of fluorescent beads, and the time-lapse 3D RI dynamics of fluorescent beads inside a HeLa cell, from which the trajectory of the beads in the HeLa cell is analyzed using spatiotemporal correlations.

Theoretical Analysis of Novel Quasi-3D Microscopy of Cell Deformation

PubMed Central

Qiu, Jun; Baik, Andrew D.; Lu, X. Lucas; Hillman, Elizabeth M. C.; Zhuang, Zhuo; Guo, X. Edward

2012-01-01

A novel quasi-three-dimensional (quasi-3D) microscopy technique has been developed to enable visualization of a cell under dynamic loading in two orthogonal planes simultaneously. The three-dimensional (3D) dynamics of the mechanical behavior of a cell under fluid flow can be examined at a high temporal resolution. In this study, a numerical model of a fluorescently dyed cell was created in 3D space, and the cell was subjected to uniaxial deformation or unidirectional fluid shear flow via finite element analysis (FEA). Therefore, the intracellular deformation in the simulated cells was exactly prescribed. Two-dimensional fluorescent images simulating the quasi-3D technique were created from the cell and its deformed states in 3D space using a point-spread function (PSF) and a convolution operation. These simulated original and deformed images were processed by a digital image correlation technique to calculate quasi-3D-based intracellular strains. The calculated strains were compared to the prescribed strains, thus providing a theoretical basis for the measurement of the accuracy of quasi-3D and wide-field microscopy-based intracellular strain measurements against the true 3D strains. The signal-to-noise ratio (SNR) of the simulated quasi-3D images was also modulated using additive Gaussian noise, and a minimum SNR of 12 was needed to recover the prescribed strains using digital image correlation. Our computational study demonstrated that quasi-3D strain measurements closely recovered the true 3D strains in uniform and fluid flow cellular strain states to within 5% strain error. PMID:22707985

2D OR NOT 2D: THE EFFECT OF DIMENSIONALITY ON THE DYNAMICS OF FINGERING CONVECTION AT LOW PRANDTL NUMBER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garaud, Pascale; Brummell, Nicholas

2015-12-10

Fingering convection (otherwise known as thermohaline convection) is an instability that occurs in stellar radiative interiors in the presence of unstable compositional gradients. Numerical simulations have been used in order to estimate the efficiency of mixing induced by this instability. However, fully three-dimensional (3D) computations in the parameter regime appropriate for stellar astrophysics (i.e., low Prandtl number) are prohibitively expensive. This raises the question of whether two-dimensional (2D) simulations could be used instead to achieve the same goals. In this work, we address this issue by comparing the outcome of 2D and 3D simulations of fingering convection at low Prandtlmore » number. We find that 2D simulations are never appropriate. However, we also find that the required 3D computational domain does not have to be very wide: the third dimension only needs to contain a minimum of two wavelengths of the fastest-growing linearly unstable mode to capture the essentially 3D dynamics of small-scale fingering. Narrow domains, however, should still be used with caution since they could limit the subsequent development of any large-scale dynamics typically associated with fingering convection.« less

THREE-DIMENSIONAL MODELING OF COHESIVE SEDIMENT TRANSPORT IN A PARTIALLY STRATIFIED MICRO-TIDAL ESTUARY TO ASSESS EFFECTIVENESS OF SEDIMENT TRAPS

EPA Science Inventory

The three-dimensional (3D) finite difference model Environmental Fluid Dynamics Code (EFDC) was used to simulate the hydrodynamics and sediment transport in a partially stratified micro-tidal estuary. The estuary modeled consisted of a 16-km reach of the St. Johns River, Florida,...

High-speed three-dimensional shape measurement for dynamic scenes using bi-frequency tripolar pulse-width-modulation fringe projection

NASA Astrophysics Data System (ADS)

Zuo, Chao; Chen, Qian; Gu, Guohua; Feng, Shijie; Feng, Fangxiaoyu; Li, Rubin; Shen, Guochen

2013-08-01

This paper introduces a high-speed three-dimensional (3-D) shape measurement technique for dynamic scenes by using bi-frequency tripolar pulse-width-modulation (TPWM) fringe projection. Two wrapped phase maps with different wavelengths can be obtained simultaneously by our bi-frequency phase-shifting algorithm. Then the two phase maps are unwrapped using a simple look-up-table based number-theoretical approach. To guarantee the robustness of phase unwrapping as well as the high sinusoidality of projected patterns, TPWM technique is employed to generate ideal fringe patterns with slight defocus. We detailed our technique, including its principle, pattern design, and system setup. Several experiments on dynamic scenes were performed, verifying that our method can achieve a speed of 1250 frames per second for fast, dense, and accurate 3-D measurements.

Roles of Diffusion Dynamics in Stem Cell Signaling and Three-Dimensional Tissue Development.

PubMed

McMurtrey, Richard J

2017-09-15

Recent advancements in the ability to construct three-dimensional (3D) tissues and organoids from stem cells and biomaterials have not only opened abundant new research avenues in disease modeling and regenerative medicine but also have ignited investigation into important aspects of molecular diffusion in 3D cellular architectures. This article describes fundamental mechanics of diffusion with equations for modeling these dynamic processes under a variety of scenarios in 3D cellular tissue constructs. The effects of these diffusion processes and resultant concentration gradients are described in the context of the major molecular signaling pathways in stem cells that both mediate and are influenced by gas and nutrient concentrations, including how diffusion phenomena can affect stem cell state, cell differentiation, and metabolic states of the cell. The application of these diffusion models and pathways is of vital importance for future studies of developmental processes, disease modeling, and tissue regeneration.

Three-Dimensional Macroporous Polypyrrole-Derived Graphene Electrode Prepared by the Hydrogen Bubble Dynamic Template for Supercapacitors and Metal-Free Catalysts.

PubMed

Yang, Xiaoqing; Liu, Anran; Zhao, Yuewu; Lu, Huijia; Zhang, Yuanjian; Wei, Wei; Li, Ying; Liu, Songqin

2015-10-28

We report a general method for the fabrication of three-dimensional (3D) macroporous graphene/conducting polymer modified electrode and nitrogen-doped graphene modified electrode. This method involves three consecutive steps. First, the 3D macroporous graphene (3D MG) electrode was fabricated electrochemically by reducing graphene oxide dispersion on different conducting substrates and used hydrogen bubbles as the dynamic template. The morphology and pore size of 3D MG could be governed by the use of surfactants and the dynamics of bubble generation and departure. Second, 3D macroporous graphene/polypyrrole (MGPPy) composites were constructed via directly electropolymerizing pyrrole monomer onto the networks of 3D MG. Due to the benefit of the good conductivity of 3D MG and pseudocapacitance of PPy, the composites manifest outstanding area specific capacitance of 196 mF cm(-2) at a current density of 1 mA cm(-2). The symmetric supercapacitor device assembled by the composite materials had a good capacity property. Finally, the nitrogen-doped MGPPy (N-MGPPy or MGPPy-X) with 3D macroporous nanostructure and well-regulated nitrogen doping was prepared via thermal treatment of the composites. The resultant N-MGPPy electrode was explored as a good electrocatalyst for the oxygen reduction reaction (ORR) with the current density value of 5.56 mA cm(-2) (-0.132 V vs Ag/AgCl). Moreover, the fuel tolerance and durability under the electrochemical environment of the N-MGPPy catalyst were found to be superior to the Pt/C catalyst.

From N=4 Galilean superparticle to three-dimensional non-relativistic N=4 superfields

NASA Astrophysics Data System (ADS)

Fedoruk, Sergey; Ivanov, Evgeny; Lukierski, Jerzy

2018-05-01

We consider the general N=4 , d = 3 Galilean superalgebra with arbitrary central charges and study its dynamical realizations. Using the nonlinear realization techniques, we introduce a class of actions for N=4 three-dimensional non-relativistic superparticle, such that they are linear in the central charge Maurer-Cartan one-forms. As a prerequisite to the quantization, we analyze the phase space constraints structure of our model for various choices of the central charges. The first class constraints generate gauge transformations, involving fermionic κ-gauge transformations. The quantization of the model gives rise to the collection of free N=4 , d = 3 Galilean superfields, which can be further employed, e.g., for description of three-dimensional non-relativistic N=4 supersymmetric theories.

An integrated guidance and control approach in three-dimensional space for hypersonic missile constrained by impact angles.

PubMed

Liu, Xiaodong; Huang, Wanwei; Du, Lifu

2017-01-01

A new robust three-dimensional integrated guidance and control (3D-IGC) approach is investigated for sliding-to-turn (STT) hypersonic missile, which encounters high uncertainties and strict impact angle constraints. First, a nonlinear state-space model with more generality is established facing to the design of 3D-IGC law. With regard to the as-built nonlinear system, a robust dynamic inversion control (RDIC) approach is proposed to overcome the robustness deficiency of traditional DIC, and then it is applied to construct the basic 3D-IGC law combining with backstepping method. In order to avoid the problems of "explosion of terms" and high-frequency chattering, an improved 3D-IGC law is further proposed by introducing dynamic surface control and continuous approximation approaches. From the computer simulation on a hypersonic missile, the proposed 3D-IGC law not only guarantees the stable flight, but also presents the precise control on terminal locations and impact angles. Moreover, it possesses smooth control output and strong robustness. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Dynamical measurements of motion behavior of free fluorescent sphere using the wide field temporal focusing microscopy with astigmatism method (Conference Presentation)

NASA Astrophysics Data System (ADS)

Lien, Chi-Hsiang; Lin, Chun-Yu; Chen, Shean-Jen; Chien, Fan-Ching

2017-02-01

A three-dimensional (3D) single fluorescent particle tracking strategy based on temporal focusing multiphoton excitation microscopy (TFMPEM) combined with astigmatism imaging is proposed for delivering nanoscale-level axial information that reveals 3D trajectories of single fluorospheres in the axially-resolved multiphoton excitation volume without z-axis scanning. It provides the dynamical ability by measuring the diffusion coefficient of fluorospheres in glycerol solutions with a position standard deviation of 14 nm and 21 nm in the lateral and axial direction and a frame rate of 100 Hz. Moreover, the optical trapping force based on the TFMPEM is minimized to avoid the interference in the tracing measurements compared to that in the spatial focusing MPE approaches. Therefore, we presented a three dimensional single particle tracking strategy to overcome the limitation of the time resolution of the multiphoton imaging using fast frame rate of TFMPEM, and provide three dimensional locations of multiple particles using an astigmatism method.

Dyamical Systems Theory and Lagrangian Data Assimilation in 4D Geophysical Fluid Dynamics

DTIC Science & Technology

The long-term goal of our project (known as OCEAN 3D +1) was to better understand and predict ocean circulation features that are fundamentally three...dimensional in space and that vary in time. In particular, we sought to quantify the dynamical processes that govern the formation , evolution, and...predictability of 3D +1 transport pathways in the ocean. Our approach was to develop algorithms to thoroughly analyze a hierarchy of model and

Evaluation of sequence alignments and oligonucleotide probes with respect to three-dimensional structure of ribosomal RNA using ARB software package

PubMed Central

Kumar, Yadhu; Westram, Ralf; Kipfer, Peter; Meier, Harald; Ludwig, Wolfgang

2006-01-01

Background Availability of high-resolution RNA crystal structures for the 30S and 50S ribosomal subunits and the subsequent validation of comparative secondary structure models have prompted the biologists to use three-dimensional structure of ribosomal RNA (rRNA) for evaluating sequence alignments of rRNA genes. Furthermore, the secondary and tertiary structural features of rRNA are highly useful and successfully employed in designing rRNA targeted oligonucleotide probes intended for in situ hybridization experiments. RNA3D, a program to combine sequence alignment information with three-dimensional structure of rRNA was developed. Integration into ARB software package, which is used extensively by the scientific community for phylogenetic analysis and molecular probe designing, has substantially extended the functionality of ARB software suite with 3D environment. Results Three-dimensional structure of rRNA is visualized in OpenGL 3D environment with the abilities to change the display and overlay information onto the molecule, dynamically. Phylogenetic information derived from the multiple sequence alignments can be overlaid onto the molecule structure in a real time. Superimposition of both statistical and non-statistical sequence associated information onto the rRNA 3D structure can be done using customizable color scheme, which is also applied to a textual sequence alignment for reference. Oligonucleotide probes designed by ARB probe design tools can be mapped onto the 3D structure along with the probe accessibility models for evaluation with respect to secondary and tertiary structural conformations of rRNA. Conclusion Visualization of three-dimensional structure of rRNA in an intuitive display provides the biologists with the greater possibilities to carry out structure based phylogenetic analysis. Coupled with secondary structure models of rRNA, RNA3D program aids in validating the sequence alignments of rRNA genes and evaluating probe target sites. Superimposition of the information derived from the multiple sequence alignment onto the molecule dynamically allows the researchers to observe any sequence inherited characteristics (phylogenetic information) in real-time environment. The extended ARB software package is made freely available for the scientific community via . PMID:16672074

Dynamic Fracture Simulations of Explosively Loaded Cylinders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arthur, Carly W.; Goto, D. M.

2015-11-30

This report documents the modeling results of high explosive experiments investigating dynamic fracture of steel (AerMet® 100 alloy) cylinders. The experiments were conducted at Lawrence Livermore National Laboratory (LLNL) during 2007 to 2008 [10]. A principal objective of this study was to gain an understanding of dynamic material failure through the analysis of hydrodynamic computer code simulations. Two-dimensional and three-dimensional computational cylinder models were analyzed using the ALE3D multi-physics computer code.

The Impact of Three-Dimensional Computational Modeling on Student Understanding of Astronomy Concepts: A Qualitative Analysis. Research Report

ERIC Educational Resources Information Center

Hansen, John; Barnett, Michael; MaKinster, James; Keating, Thomas

2004-01-01

In this study, we explore an alternate mode for teaching and learning the dynamic, three-dimensional (3D) relationships that are central to understanding astronomical concepts. To this end, we implemented an innovative undergraduate course in which we used inexpensive computer modeling tools. As the second of a two-paper series, this report…

Three dimensional cross-correlation dynamic light scattering by non-ergodic turbid media.

PubMed

Haro-Pérez, C; Ojeda-Mendoza, G J; Rojas-Ochoa, L F

2011-06-28

We investigate dynamic light scattering by non-ergodic turbid media with an adapted version of the method proposed by Pusey and van Megen [Physica A 157, 705 (1989)]. Our formulation follows the derivation of the original method by extending it to the three dimensional cross-correlation scheme (3DDLS). The main finding is an expression to obtain the dynamic structure factor from light scattering that takes into account the system turbidity and the peculiarities of the 3D geometry. From 3DDLS measurements in well-controlled solid-like systems of different turbidity, we confirm that our results can be interpreted reasonably well by the theoretical approach described here. Good agreement is found with earlier reported results on similar systems.

A spectral-Tchebychev solution for three-dimensional dynamics of curved beams under mixed boundary conditions

NASA Astrophysics Data System (ADS)

Bediz, Bekir; Aksoy, Serdar

2018-01-01

This paper presents the application of the spectral-Tchebychev (ST) technique for solution of three-dimensional dynamics of curved beams/structures having variable and arbitrary cross-section under mixed boundary conditions. To accurately capture the vibrational behavior of curved structures, a three-dimensional (3D) solution approach is required since these structures generally exhibit coupled motions. In this study, the integral boundary value problem (IBVP) governing the dynamics of the curved structures is found using extended Hamilton's principle where the strain energy is expressed using 3D linear elasticity equation. To solve the IBVP numerically, the 3D spectral Tchebychev (3D-ST) approach is used. To evaluate the integral and derivative operations defined by the IBVP and to render the complex geometry into an equivalent straight beam with rectangular cross-section, a series of coordinate transformations are applied. To validate and assess the performance of the presented solution approach, two case studies are performed: (i) curved beam with rectangular cross-section, (ii) curved and pretwisted beam with airfoil cross-section. In both cases, the results (natural frequencies and mode shapes) are also found using a finite element (FE) solution approach. It is shown that the difference in predicted natural frequencies are less than 1%, and the mode shapes are in excellent agreement based on the modal assurance criteria (MAC) analyses; however, the presented spectral-Tchebychev solution approach significantly reduces the computational burden. Therefore, it can be concluded that the presented solution approach can capture the 3D vibrational behavior of curved beams as accurately as an FE solution, but for a fraction of the computational cost.

Inverse and Direct Energy Cascades in Three-Dimensional Magnetohydrodynamic Turbulence at Low Magnetic Reynolds Number

NASA Astrophysics Data System (ADS)

Baker, Nathaniel T.; Pothérat, Alban; Davoust, Laurent; Debray, François

2018-06-01

This experimental study analyzes the relationship between the dimensionality of turbulence and the upscale or downscale nature of its energy transfers. We do so by forcing low-R m magnetohydrodynamic turbulence in a confined channel, while precisely controlling its dimensionality by means of an externally applied magnetic field. We first identify a specific length scale l^⊥ c that separates smaller 3D structures from larger quasi-2D ones. We then show that an inverse energy cascade of horizontal kinetic energy along horizontal scales is always observable at large scales, and that it extends well into the region of 3D structures. At the same time, a direct energy cascade confined to the smallest and strongly 3D scales is observed. These dynamics therefore appear not to be simply determined by the dimensionality of individual scales, nor by the forcing scale, unlike in other studies. In fact, our findings suggest that the relationship between kinematics and dynamics is not universal and may strongly depend on the forcing and dissipating mechanisms at play.

Structural and congenital heart disease interventions: the role of three-dimensional printing.

PubMed

Meier, L M; Meineri, M; Qua Hiansen, J; Horlick, E M

2017-02-01

Advances in catheter-based interventions in structural and congenital heart disease have mandated an increased demand for three-dimensional (3D) visualisation of complex cardiac anatomy. Despite progress in 3D imaging modalities, the pre- and periprocedural visualisation of spatial anatomy is relegated to two-dimensional flat screen representations. 3D printing is an evolving technology based on the concept of additive manufacturing, where computerised digital surface renders are converted into physical models. Printed models replicate complex structures in tangible forms that cardiovascular physicians and surgeons can use for education, preprocedural planning and device testing. In this review we discuss the different steps of the 3D printing process, which include image acquisition, segmentation, printing methods and materials. We also examine the expanded applications of 3D printing in the catheter-based treatment of adult patients with structural and congenital heart disease while highlighting the current limitations of this technology in terms of segmentation, model accuracy and dynamic capabilities. Furthermore, we provide information on the resources needed to establish a hospital-based 3D printing laboratory.

Dynamic concision for three-dimensional reconstruction of human organ built with virtual reality modelling language (VRML).

PubMed

Yu, Zheng-yang; Zheng, Shu-sen; Chen, Lei-ting; He, Xiao-qian; Wang, Jian-jun

2005-07-01

This research studies the process of 3D reconstruction and dynamic concision based on 2D medical digital images using virtual reality modelling language (VRML) and JavaScript language, with a focus on how to realize the dynamic concision of 3D medical model with script node and sensor node in VRML. The 3D reconstruction and concision of body internal organs can be built with such high quality that they are better than those obtained from the traditional methods. With the function of dynamic concision, the VRML browser can offer better windows for man-computer interaction in real-time environment than ever before. 3D reconstruction and dynamic concision with VRML can be used to meet the requirement for the medical observation of 3D reconstruction and have a promising prospect in the fields of medical imaging.

Dynamic concision for three-dimensional reconstruction of human organ built with virtual reality modelling language (VRML)*

PubMed Central

Yu, Zheng-yang; Zheng, Shu-sen; Chen, Lei-ting; He, Xiao-qian; Wang, Jian-jun

2005-01-01

This research studies the process of 3D reconstruction and dynamic concision based on 2D medical digital images using virtual reality modelling language (VRML) and JavaScript language, with a focus on how to realize the dynamic concision of 3D medical model with script node and sensor node in VRML. The 3D reconstruction and concision of body internal organs can be built with such high quality that they are better than those obtained from the traditional methods. With the function of dynamic concision, the VRML browser can offer better windows for man-computer interaction in real-time environment than ever before. 3D reconstruction and dynamic concision with VRML can be used to meet the requirement for the medical observation of 3D reconstruction and have a promising prospect in the fields of medical imaging. PMID:15973760

Visualization of spatial-temporal data based on 3D virtual scene

NASA Astrophysics Data System (ADS)

Wang, Xianghong; Liu, Jiping; Wang, Yong; Bi, Junfang

2009-10-01

The main purpose of this paper is to realize the expression of the three-dimensional dynamic visualization of spatialtemporal data based on three-dimensional virtual scene, using three-dimensional visualization technology, and combining with GIS so that the people's abilities of cognizing time and space are enhanced and improved by designing dynamic symbol and interactive expression. Using particle systems, three-dimensional simulation, virtual reality and other visual means, we can simulate the situations produced by changing the spatial location and property information of geographical entities over time, then explore and analyze its movement and transformation rules by changing the interactive manner, and also replay history and forecast of future. In this paper, the main research object is the vehicle track and the typhoon path and spatial-temporal data, through three-dimensional dynamic simulation of its track, and realize its timely monitoring its trends and historical track replaying; according to visualization techniques of spatialtemporal data in Three-dimensional virtual scene, providing us with excellent spatial-temporal information cognitive instrument not only can add clarity to show spatial-temporal information of the changes and developments in the situation, but also be used for future development and changes in the prediction and deduction.

Rolled-up Functionalized Nanomembranes as Three-Dimensional Cavities for Single Cell Studies

PubMed Central

2014-01-01

We use micropatterning and strain engineering to encapsulate single living mammalian cells into transparent tubular architectures consisting of three-dimensional (3D) rolled-up nanomembranes. By using optical microscopy, we demonstrate that these structures are suitable for the scrutiny of cellular dynamics within confined 3D-microenvironments. We show that spatial confinement of mitotic mammalian cells inside tubular architectures can perturb metaphase plate formation, delay mitotic progression, and cause chromosomal instability in both a transformed and nontransformed human cell line. These findings could provide important clues into how spatial constraints dictate cellular behavior and function. PMID:24598026

3D Protein Dynamics in the Cell Nucleus.

PubMed

Singh, Anand P; Galland, Rémi; Finch-Edmondson, Megan L; Grenci, Gianluca; Sibarita, Jean-Baptiste; Studer, Vincent; Viasnoff, Virgile; Saunders, Timothy E

2017-01-10

The three-dimensional (3D) architecture of the cell nucleus plays an important role in protein dynamics and in regulating gene expression. However, protein dynamics within the 3D nucleus are poorly understood. Here, we present, to our knowledge, a novel combination of 1) single-objective based light-sheet microscopy, 2) photoconvertible proteins, and 3) fluorescence correlation microscopy, to quantitatively measure 3D protein dynamics in the nucleus. We are able to acquire >3400 autocorrelation functions at multiple spatial positions within a nucleus, without significant photobleaching, allowing us to make reliable estimates of diffusion dynamics. Using this tool, we demonstrate spatial heterogeneity in Polymerase II dynamics in live U2OS cells. Further, we provide detailed measurements of human-Yes-associated protein diffusion dynamics in a human gastric cancer epithelial cell line. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Annular dynamics of memo3D annuloplasty ring evaluated by 3D transesophageal echocardiography.

PubMed

Nishi, Hiroyuki; Toda, Koichi; Miyagawa, Shigeru; Yoshikawa, Yasushi; Fukushima, Satsuki; Yoshioka, Daisuke; Sawa, Yoshiki

2018-04-01

We assessed the mitral annular motion after mitral valve repair with the Sorin Memo 3D® (Sorin Group Italia S.r.L., Saluggia, Italy), which is a unique complete semirigid annuloplasty ring intended to restore the systolic profile of the mitral annulus while adapting to the physiologic dynamism of the annulus, using transesophageal real-time three-dimensional echocardiography. 17 patients (12 male; mean age 60.4 ± 14.9 years) who underwent mitral annuloplasty using the Memo 3D ring were investigated. Mitral annular motion was assessed using QLAB®version8 allowing for a full evaluation of the mitral annulus dynamics. The mitral annular dimensions were measured throughout the cardiac cycle using 4D MV assessment2® while saddle shape was assessed through sequential measurements by RealView®. Saddle shape configuration of the mitral annulus and posterior and anterior leaflet motion could be observed during systole and diastole. The mitral annular area changed during the cardiac cycle by 5.7 ± 1.8%.The circumference length and diameter also changed throughout the cardiac cycle. The annular height was significantly higher in mid-systole than in mid-diastole (p < 0.05). The Memo 3D ring maintained a physiological saddle-shape configuration throughout the cardiac cycle. Real-time three-dimensional echocardiography analysis confirmed the motion and flexibility of the Memo 3D ring upon implantation.

Perceiving environmental properties from motion information: Minimal conditions

NASA Technical Reports Server (NTRS)

Proffitt, Dennis R.; Kaiser, Mary K.

1989-01-01

The status of motion as a minimal information source for perceiving the environmental properties of surface segregation, three-dimensional (3-D) form, displacement, and dynamics is discussed. The selection of these particular properties was motivated by a desire to present research on perceiving properties that span the range of dimensional complexity.

Virtual Environment for Surgical Room of the Future.

DTIC Science & Technology

1995-10-01

Design; 1. wire frame Dynamic Interaction 2. surface B. Acoustic Three-Dimensional Modeling; 3. solid based on radiosity modeling B. Dynamic...infection control of people and E. Rendering and Shadowing equipment 1. ray tracing D. Fluid Flow 2. radiosity F. Animation OBJECT RECOGNITION COMMUNICATION

2-D and 3-D oscillating wing aerodynamics for a range of angles of attack including stall

NASA Technical Reports Server (NTRS)

Piziali, R. A.

1994-01-01

A comprehensive experimental investigation of the pressure distribution over a semispan wing undergoing pitching motions representative of a helicopter rotor blade was conducted. Testing the wing in the nonrotating condition isolates the three-dimensional (3-D) blade aerodynamic and dynamic stall characteristics from the complications of the rotor blade environment. The test has generated a very complete, detailed, and accurate body of data. These data include static and dynamic pressure distributions, surface flow visualizations, two-dimensional (2-D) airfoil data from the same model and installation, and important supporting blockage and wall pressure distributions. This body of data is sufficiently comprehensive and accurate that it can be used for the validation of rotor blade aerodynamic models over a broad range of the important parameters including 3-D dynamic stall. This data report presents all the cycle-averaged lift, drag, and pitching moment coefficient data versus angle of attack obtained from the instantaneous pressure data for the 3-D wing and the 2-D airfoil. Also presented are examples of the following: cycle-to-cycle variations occurring for incipient or lightly stalled conditions; 3-D surface flow visualizations; supporting blockage and wall pressure distributions; and underlying detailed pressure results.

Lack of robustness of textural measures obtained from 3D brain tumor MRIs impose a need for standardization.

PubMed

Molina, David; Pérez-Beteta, Julián; Martínez-González, Alicia; Martino, Juan; Velasquez, Carlos; Arana, Estanislao; Pérez-García, Víctor M

2017-01-01

Textural measures have been widely explored as imaging biomarkers in cancer. However, their robustness under dynamic range and spatial resolution changes in brain 3D magnetic resonance images (MRI) has not been assessed. The aim of this work was to study potential variations of textural measures due to changes in MRI protocols. Twenty patients harboring glioblastoma with pretreatment 3D T1-weighted MRIs were included in the study. Four different spatial resolution combinations and three dynamic ranges were studied for each patient. Sixteen three-dimensional textural heterogeneity measures were computed for each patient and configuration including co-occurrence matrices (CM) features and run-length matrices (RLM) features. The coefficient of variation was used to assess the robustness of the measures in two series of experiments corresponding to (i) changing the dynamic range and (ii) changing the matrix size. No textural measures were robust under dynamic range changes. Entropy was the only textural feature robust under spatial resolution changes (coefficient of variation under 10% in all cases). Textural measures of three-dimensional brain tumor images are not robust neither under dynamic range nor under matrix size changes. Standards should be harmonized to use textural features as imaging biomarkers in radiomic-based studies. The implications of this work go beyond the specific tumor type studied here and pose the need for standardization in textural feature calculation of oncological images.

Geometrically nonlinear analysis of layered composite plates and shells

NASA Technical Reports Server (NTRS)

Chao, W. C.; Reddy, J. N.

1983-01-01

A degenerated three dimensional finite element, based on the incremental total Lagrangian formulation of a three dimensional layered anisotropic medium was developed. Its use in the geometrically nonlinear, static and dynamic, analysis of layered composite plates and shells is demonstrated. A two dimenisonal finite element based on the Sanders shell theory with the von Karman (nonlinear) strains was developed. It is shown that the deflections obtained by the 2D shell element deviate from those obtained by the more accurate 3D element for deep shells. The 3D degenerated element can be used to model general shells that are not necessarily doubly curved. The 3D degenerated element is computationally more demanding than the 2D shell theory element for a given problem. It is found that the 3D element is an efficient element for the analysis of layered composite plates and shells undergoing large displacements and transient motion.

Three-dimensional simulations of void collapse in energetic materials

NASA Astrophysics Data System (ADS)

Rai, Nirmal Kumar; Udaykumar, H. S.

2018-03-01

The collapse of voids in porous energetic materials leads to hot-spot formation and reaction initiation. This work advances the current knowledge of the dynamics of void collapse and hot-spot formation using 3D reactive void collapse simulations in HMX. Four different void shapes, i.e., sphere, cylinder, plate, and ellipsoid, are studied. For all four shapes, collapse generates complex three-dimensional (3D) baroclinic vortical structures. The hot spots are collocated with regions of intense vorticity. The differences in the vortical structures for the different void shapes are shown to significantly impact the relative sensitivity of the voids. Voids of high surface area generate hot spots of greater intensity; intricate, highly contorted vortical structures lead to hot spots of corresponding tortuosity and therefore enhanced growth rates of reaction fronts. In addition, all 3D voids are shown to be more sensitive than their two-dimensional (2D) counterparts. The results provide physical insights into hot-spot formation and growth and point to the limitations of 2D analyses of hot-spot formation.

Adipogenesis of human adipose-derived stem cells within three-dimensional hollow fiber-based bioreactors.

PubMed

Gerlach, Jörg C; Lin, Yen-Chih; Brayfield, Candace A; Minteer, Danielle M; Li, Han; Rubin, J Peter; Marra, Kacey G

2012-01-01

To further differentiate adipose-derived stem cells (ASCs) into mature adipocytes and create three-dimensional (3D) adipose tissue in vitro, we applied multicompartment hollow fiber-based bioreactor technology with decentral mass exchange for more physiological substrate gradients and integral oxygenation. We hypothesize that a dynamic 3D perfusion in such a bioreactor will result in longer-term culture of human adipocytes in vitro, thus providing metabolically active tissue serving as a diagnostic model for screening drugs to treat diabetes. ASCs were isolated from discarded human abdominal subcutaneous adipose tissue and then inoculated into dynamic 3D culture bioreactors to undergo adipogenic differentiation. Insulin-stimulated glucose uptake from the medium was assessed with and without TNF-alpha. 3D adipose tissue was generated in the 3D-bioreactors. Immunohistochemical staining indicated that 3D-bioreactor culture displayed multiple mature adipocyte markers with more unilocular morphologies as compared with two-dimensional (2D) cultures. Results of real-time polymerase chain reaction showed 3D-bioreactor treatment had more efficient differentiation in fatty acid-binding protein 4 expression. Repeated insulin stimulation resulted in increased glucose uptake, with a return to baseline between testing. Importantly, TNF-alpha inhibited glucose uptake, an indication of the metabolic activity of the tissue. 3D bioreactors allow more mature adipocyte differentiation of ASCs compared with traditional 2D culture and generate adipose tissue in vitro for up to 2 months. Reproducible metabolic activity of the adipose tissue in the bioreactor was demonstrated, which is potentially useful for drug discovery. We present here, to the best of our knowledge for the first time, the development of a coherent 3D high density fat-like tissue consisting of unilocular structure from primary adipose stem cells in vitro.

Adipogenesis of Human Adipose-Derived Stem Cells Within Three-Dimensional Hollow Fiber-Based Bioreactors

PubMed Central

Gerlach, Jörg C.; Lin, Yen-Chih; Brayfield, Candace A.; Minteer, Danielle M.; Li, Han; Rubin, J. Peter

2012-01-01

To further differentiate adipose-derived stem cells (ASCs) into mature adipocytes and create three-dimensional (3D) adipose tissue in vitro, we applied multicompartment hollow fiber-based bioreactor technology with decentral mass exchange for more physiological substrate gradients and integral oxygenation. We hypothesize that a dynamic 3D perfusion in such a bioreactor will result in longer-term culture of human adipocytes in vitro, thus providing metabolically active tissue serving as a diagnostic model for screening drugs to treat diabetes. ASCs were isolated from discarded human abdominal subcutaneous adipose tissue and then inoculated into dynamic 3D culture bioreactors to undergo adipogenic differentiation. Insulin-stimulated glucose uptake from the medium was assessed with and without TNF-alpha. 3D adipose tissue was generated in the 3D-bioreactors. Immunohistochemical staining indicated that 3D-bioreactor culture displayed multiple mature adipocyte markers with more unilocular morphologies as compared with two-dimensional (2D) cultures. Results of real-time polymerase chain reaction showed 3D-bioreactor treatment had more efficient differentiation in fatty acid-binding protein 4 expression. Repeated insulin stimulation resulted in increased glucose uptake, with a return to baseline between testing. Importantly, TNF-alpha inhibited glucose uptake, an indication of the metabolic activity of the tissue. 3D bioreactors allow more mature adipocyte differentiation of ASCs compared with traditional 2D culture and generate adipose tissue in vitro for up to 2 months. Reproducible metabolic activity of the adipose tissue in the bioreactor was demonstrated, which is potentially useful for drug discovery. We present here, to the best of our knowledge for the first time, the development of a coherent 3D high density fat-like tissue consisting of unilocular structure from primary adipose stem cells in vitro. PMID:21902468

Three-dimensional mapping and regulation of action potential propagation in nanoelectronics-innervated tissues.

PubMed

Dai, Xiaochuan; Zhou, Wei; Gao, Teng; Liu, Jia; Lieber, Charles M

2016-09-01

Real-time mapping and manipulation of electrophysiology in three-dimensional (3D) tissues could have important impacts on fundamental scientific and clinical studies, yet realization is hampered by a lack of effective methods. Here we introduce tissue-scaffold-mimicking 3D nanoelectronic arrays consisting of 64 addressable devices with subcellular dimensions and a submillisecond temporal resolution. Real-time extracellular action potential (AP) recordings reveal quantitative maps of AP propagation in 3D cardiac tissues, enable in situ tracing of the evolving topology of 3D conducting pathways in developing cardiac tissues and probe the dynamics of AP conduction characteristics in a transient arrhythmia disease model and subsequent tissue self-adaptation. We further demonstrate simultaneous multisite stimulation and mapping to actively manipulate the frequency and direction of AP propagation. These results establish new methodologies for 3D spatiotemporal tissue recording and control, and demonstrate the potential to impact regenerative medicine, pharmacology and electronic therapeutics.

Three-dimensional mapping and regulation of action potential propagation in nanoelectronics innervated tissues

PubMed Central

Dai, Xiaochuan; Zhou, Wei; Gao, Teng; Liu, Jia; Lieber, Charles M.

2016-01-01

Real-time mapping and manipulation of electrophysiology in three-dimensional (3D) tissues could impact broadly fundamental scientific and clinical studies, yet realization lacks effective methods. Here we introduce tissue-scaffold-mimicking 3D nanoelectronic arrays consisting of 64 addressable devices with subcellular dimensions and sub-millisecond time-resolution. Real-time extracellular action potential (AP) recordings reveal quantitative maps of AP propagation in 3D cardiac tissues, enable in situ tracing of the evolving topology of 3D conducting pathways in developing cardiac tissues, and probe the dynamics of AP conduction characteristics in a transient arrhythmia disease model and subsequent tissue self-adaptation. We further demonstrate simultaneous multi-site stimulation and mapping to manipulate actively the frequency and direction of AP propagation. These results establish new methodologies for 3D spatiotemporal tissue recording and control, and demonstrate the potential to impact regenerative medicine, pharmacology and electronic therapeutics. PMID:27347837

Reconfigurable Three-Dimensional Gold Nanorod Plasmonic Nanostructures Organized on DNA Origami Tripod.

PubMed

Zhan, Pengfei; Dutta, Palash K; Wang, Pengfei; Song, Gang; Dai, Mingjie; Zhao, Shu-Xia; Wang, Zhen-Gang; Yin, Peng; Zhang, Wei; Ding, Baoquan; Ke, Yonggang

2017-02-28

Distinct electromagnetic properties can emerge from the three-dimensional (3D) configuration of a plasmonic nanostructure. Furthermore, the reconfiguration of a dynamic plasmonic nanostructure, driven by physical or chemical stimuli, may generate a tailored plasmonic response. In this work, we constructed a 3D reconfigurable plasmonic nanostructure with controllable, reversible conformational transformation using bottom-up DNA self-assembly. Three gold nanorods (AuNRs) were positioned onto a reconfigurable DNA origami tripod. The internanorod angle and distance were precisely tuned through operating the origami tripod by toehold-mediated strand displacement. The transduction of conformational change manifested into a controlled shift of the plasmonic resonance peak, which was studied by dark-field microscopy, and agrees well with electrodynamic calculations. This new 3D plasmonic nanostructure not only provides a method to study the plasmonic resonance of AuNRs at prescribed 3D conformations but also demonstrates that DNA origami can serve as a general self-assembly platform for constructing various 3D reconfigurable plasmonic nanostructures with customized optical properties.

[The dynamic concision for three-dimensional reconstruction of human organ built with virtual reality modeling language (VRML)].

PubMed

Yu, Zhengyang; Zheng, Shusen; Chen, Huaiqing; Wang, Jianjun; Xiong, Qingwen; Jing, Wanjun; Zeng, Yu

2006-10-01

This research studies the process of dynamic concision and 3D reconstruction from medical body data using VRML and JavaScript language, focuses on how to realize the dynamic concision of 3D medical model built with VRML. The 2D medical digital images firstly are modified and manipulated by 2D image software. Then, based on these images, 3D mould is built with VRML and JavaScript language. After programming in JavaScript to control 3D model, the function of dynamic concision realized by Script node and sensor node in VRML. The 3D reconstruction and concision of body internal organs can be formed in high quality near to those got in traditional methods. By this way, with the function of dynamic concision, VRML browser can offer better windows of man-computer interaction in real time environment than before. 3D reconstruction and dynamic concision with VRML can be used to meet the requirement for the medical observation of 3D reconstruction and has a promising prospect in the fields of medical image.

Infusion of a Gaming Paradigm into Computer-Aided Engineering Design Tools

DTIC Science & Technology

2012-05-03

Virtual Test Bed (VTB), and the gaming tool, Unity3D . This hybrid gaming environment coupled a three-dimensional (3D) multibody vehicle system model...from Google Earth to the 3D visual front-end fabricated around Unity3D . The hybrid environment was sufficiently developed to support analyses of the...ndFr Cti3r4 G’OjrdFr ctior-2 The VTB simulation of the vehicle dynamics ran concurrently with and interacted with the gaming engine, Unity3D which

Instructor-Led Approach to Integrating an Augmented Reality Sandbox into a Large-Enrollment Introductory Geoscience Course for Nonmajors Produces No Gains

ERIC Educational Resources Information Center

Giorgis, Scott; Mahlen, Nancy; Anne, Kirk

2017-01-01

The augmented reality (AR) sandbox bridges the gap between two-dimensional (2D) and three-dimensional (3D) visualization by projecting a digital topographic map onto a sandbox landscape. As the landscape is altered, the map dynamically adjusts, providing an opportunity to discover how to read topographic maps. We tested the hypothesis that the AR…

Efficient three-dimensional Poisson solvers in open rectangular conducting pipe

NASA Astrophysics Data System (ADS)

Qiang, Ji

2016-06-01

Three-dimensional (3D) Poisson solver plays an important role in the study of space-charge effects on charged particle beam dynamics in particle accelerators. In this paper, we propose three new 3D Poisson solvers for a charged particle beam in an open rectangular conducting pipe. These three solvers include a spectral integrated Green function (IGF) solver, a 3D spectral solver, and a 3D integrated Green function solver. These solvers effectively handle the longitudinal open boundary condition using a finite computational domain that contains the beam itself. This saves the computational cost of using an extra larger longitudinal domain in order to set up an appropriate finite boundary condition. Using an integrated Green function also avoids the need to resolve rapid variation of the Green function inside the beam. The numerical operational cost of the spectral IGF solver and the 3D IGF solver scales as O(N log(N)) , where N is the number of grid points. The cost of the 3D spectral solver scales as O(Nn N) , where Nn is the maximum longitudinal mode number. We compare these three solvers using several numerical examples and discuss the advantageous regime of each solver in the physical application.

Measurement of three-dimensional posture and trajectory of lower body during standing long jumping utilizing body-mounted sensors.

PubMed

Ibata, Yuki; Kitamura, Seiji; Motoi, Kosuke; Sagawa, Koichi

2013-01-01

The measurement method of three-dimensional posture and flying trajectory of lower body during jumping motion using body-mounted wireless inertial measurement units (WIMU) is introduced. The WIMU is composed of three-dimensional (3D) accelerometer and gyroscope of two kinds with different dynamic range and one 3D geomagnetic sensor to adapt to quick movement. Three WIMUs are mounted under the chest, right thigh and right shank. Thin film pressure sensors are connected to the shank WIMU and are installed under right heel and tiptoe to distinguish the state of the body motion between grounding and jumping. Initial and final postures of trunk, thigh and shank at standing-still are obtained using gravitational acceleration and geomagnetism. The posture of body is determined using the 3D direction of each segment updated by the numerical integration of angular velocity. Flying motion is detected from pressure sensors and 3D flying trajectory is derived by the double integration of trunk acceleration applying the 3D velocity of trunk at takeoff. Standing long jump experiments are performed and experimental results show that the joint angle and flying trajectory agree with the actual motion measured by the optical motion capture system.

Microfluidic 3D cell culture: potential application for tissue-based bioassays

PubMed Central

Li, XiuJun (James); Valadez, Alejandra V.; Zuo, Peng; Nie, Zhihong

2014-01-01

Current fundamental investigations of human biology and the development of therapeutic drugs, commonly rely on two-dimensional (2D) monolayer cell culture systems. However, 2D cell culture systems do not accurately recapitulate the structure, function, physiology of living tissues, as well as highly complex and dynamic three-dimensional (3D) environments in vivo. The microfluidic technology can provide micro-scale complex structures and well-controlled parameters to mimic the in vivo environment of cells. The combination of microfluidic technology with 3D cell culture offers great potential for in vivo-like tissue-based applications, such as the emerging organ-on-a-chip system. This article will review recent advances in microfluidic technology for 3D cell culture and their biological applications. PMID:22793034

Establishment and verification of three-dimensional dynamic model for heavy-haul train-track coupled system

NASA Astrophysics Data System (ADS)

Liu, Pengfei; Zhai, Wanming; Wang, Kaiyun

2016-11-01

For the long heavy-haul train, the basic principles of the inter-vehicle interaction and train-track dynamic interaction are analysed firstly. Based on the theories of train longitudinal dynamics and vehicle-track coupled dynamics, a three-dimensional (3-D) dynamic model of the heavy-haul train-track coupled system is established through a modularised method. Specifically, this model includes the subsystems such as the train control, the vehicle, the wheel-rail relation and the line geometries. And for the calculation of the wheel-rail interaction force under the driving or braking conditions, the large creep phenomenon that may occur within the wheel-rail contact patch is considered. For the coupler and draft gear system, the coupler forces in three directions and the coupler lateral tilt angles in curves are calculated. Then, according to the characteristics of the long heavy-haul train, an efficient solving method is developed to improve the computational efficiency for such a large system. Some basic principles which should be followed in order to meet the requirement of calculation accuracy are determined. Finally, the 3-D train-track coupled model is verified by comparing the calculated results with the running test results. It is indicated that the proposed dynamic model could simulate the dynamic performance of the heavy-haul train well.

Three-dimensional Dendritic Needle Network model with application to Al-Cu directional solidification experiments

NASA Astrophysics Data System (ADS)

Tourret, D.; Karma, A.; Clarke, A. J.; Gibbs, P. J.; Imhoff, S. D.

2015-06-01

We present a three-dimensional (3D) extension of a previously proposed multi-scale Dendritic Needle Network (DNN) approach for the growth of complex dendritic microstructures. Using a new formulation of the DNN dynamics equations for dendritic paraboloid-branches of a given thickness, one can directly extend the DNN approach to 3D modeling. We validate this new formulation against known scaling laws and analytical solutions that describe the early transient and steady-state growth regimes, respectively. Finally, we compare the predictions of the model to in situ X-ray imaging of Al-Cu alloy solidification experiments. The comparison shows a very good quantitative agreement between 3D simulations and thin sample experiments. It also highlights the importance of full 3D modeling to accurately predict the primary dendrite arm spacing that is significantly over-estimated by 2D simulations.

Three-dimensional Dendritic Needle Network model with application to Al-Cu directional solidification experiments

DOE PAGES

Tourret, D.; Karma, A.; Clarke, A. J.; ...

2015-06-11

We present a three-dimensional (3D) extension of a previously proposed multi-scale Dendritic Needle Network (DNN) approach for the growth of complex dendritic microstructures. Using a new formulation of the DNN dynamics equations for dendritic paraboloid-branches of a given thickness, one can directly extend the DNN approach to 3D modeling. We validate this new formulation against known scaling laws and analytical solutions that describe the early transient and steady-state growth regimes, respectively. Finally, we compare the predictions of the model to in situ X-ray imaging of Al-Cu alloy solidification experiments. The comparison shows a very good quantitative agreement between 3D simulationsmore » and thin sample experiments. It also highlights the importance of full 3D modeling to accurately predict the primary dendrite arm spacing that is significantly over-estimated by 2D simulations.« less

Dynamics of optically levitated microparticles in vacuum placed in 2D and 3D optical potentials possessing orbital angular momentum

NASA Astrophysics Data System (ADS)

Arita, Yoshihiko; Mazilu, Michael; Chen, Mingzhou; Vettenburg, Tom; Auñón, Juan M.; Wright, Ewan M.; Dholakia, Kishan

2017-04-01

We demonstrate the transfer of orbital angular momentum to optically levitated microparticles in vacuum [1]. We prepare two-dimensional and three-dimensional optical potentials. In the former case the microparticle is placed within a Laguerre-Gaussian beam and orbits the annular beam profile with increasing angular velocity as the air drag coefficient is reduced. We explore the particle dynamics as a function of the topological charge of the levitating beam. Our results reveal that there is a fundamental limit to the orbital angular momentum that may be transferred to a trapped particle, dependent upon the beam parameters and inertial forces present. This effect was predicted theoretically [2] and can be understood considering the underlying dynamics arising from the link between the magnitude of the azimuthal index and the beam radius [3]. Whilst a Laguerre-Gaussian beam scales in size with azimuthal index `, recently we have created a "perfect" vortex beam whose radial intensity profile and radius are both independent of topological charge [4, 5]. As the Fourier transform of a perfect vortex yields a Bessel beam. Imaging a perfect vortex, with its subsequent propagation thus realises a complex three dimensional optical field. In this scenario we load individual silica microparticles into this field and observe their trajectories. The optical gradient and scattering forces interplay with the inertial and gravitational forces acting on the trapped particle, including the rotational degrees of freedom. As a result the trapped microparticle exhibits a complex three dimensional motion that includes a periodic orbital motion between the Bessel and the perfect vortex beam. We are able to determine the three dimensional optical potential in situ by tracking the particle. This first demonstration of trapping microparticles within a complex three dimensional optical potential in vacuum opens up new possibilities for fundamental studies of many-body dynamics, mesoscopic entanglement [6, 7], and optical binding [8, 9].

Dynamic 3D echocardiography in virtual reality

PubMed Central

van den Bosch, Annemien E; Koning, Anton HJ; Meijboom, Folkert J; McGhie, Jackie S; Simoons, Maarten L; van der Spek, Peter J; Bogers, Ad JJC

2005-01-01

Background This pilot study was performed to evaluate whether virtual reality is applicable for three-dimensional echocardiography and if three-dimensional echocardiographic 'holograms' have the potential to become a clinically useful tool. Methods Three-dimensional echocardiographic data sets from 2 normal subjects and from 4 patients with a mitral valve pathological condition were included in the study. The three-dimensional data sets were acquired with the Philips Sonos 7500 echo-system and transferred to the BARCO (Barco N.V., Kortrijk, Belgium) I-space. Ten independent observers assessed the 6 three-dimensional data sets with and without mitral valve pathology. After 10 minutes' instruction in the I-Space, all of the observers could use the virtual pointer that is necessary to create cut planes in the hologram. Results The 10 independent observers correctly assessed the normal and pathological mitral valve in the holograms (analysis time approximately 10 minutes). Conclusion this report shows that dynamic holographic imaging of three-dimensional echocardiographic data is feasible. However, the applicability and use-fullness of this technology in clinical practice is still limited. PMID:16375768

Three-dimensional tomographic imaging for dynamic radiation behavior study using infrared imaging video bolometers in large helical device plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sano, Ryuichi; Iwama, Naofumi; Peterson, Byron J.

A three-dimensional (3D) tomography system using four InfraRed imaging Video Bolometers (IRVBs) has been designed with a helical periodicity assumption for the purpose of plasma radiation measurement in the large helical device. For the spatial inversion of large sized arrays, the system has been numerically and experimentally examined using the Tikhonov regularization with the criterion of minimum generalized cross validation, which is the standard solver of inverse problems. The 3D transport code EMC3-EIRENE for impurity behavior and related radiation has been used to produce phantoms for numerical tests, and the relative calibration of the IRVB images has been carried outmore » with a simple function model of the decaying plasma in a radiation collapse. The tomography system can respond to temporal changes in the plasma profile and identify the 3D dynamic behavior of radiation, such as the radiation enhancement that starts from the inboard side of the torus, during the radiation collapse. The reconstruction results are also consistent with the output signals of a resistive bolometer. These results indicate that the designed 3D tomography system is available for the 3D imaging of radiation. The first 3D direct tomographic measurement of a magnetically confined plasma has been achieved.« less

A novel procedure to assess anismus using three-dimensional dynamic anal ultrasonography.

PubMed

Murad-Regadas, S M; Regadas, F S P; Rodrigues, L V; Souza, M H L P; Lima, D M R; Silva, F R S; Filho, F S P R

2007-02-01

This study aimed to determine the value of three-dimensional (3D) dynamic endosonography in the assessment of anismus. Sixty-one women submitted to anorectal manometry were enrolled including 40 healthy women and 21 patients with anismus diagnosed by manometry. Patients were submitted to 3D endosonography. Images were acquired at rest and during straining and analysed in axial and midline longitudinal planes. Sphincter integrity was quantified. The angle between the internal edge of the puborectalis with a vertical line according to the anal canal axis was calculated at rest and during straining. The angle increased in 39 of the 40 normal individuals and decreased in all patients with anismus during straining compared with the angle at rest (88.36 degrees ) and straining (98.65 degrees ) in normal individuals. In the anismus group, the angle decreased at rest (90.91 degrees ) and straining (84.89 degrees ). The difference between angle sizes in normal and anismus patients during straining was statistically significant (P < 0.5). Three-dimensional endosonography is a useful method to assess patients with anismus confirming the anorectal manometric results.

Vorticity and helicity decompositions and dynamics with real Schur form of the velocity gradient

NASA Astrophysics Data System (ADS)

Zhu, Jian-Zhou

2018-03-01

The real Schur form (RSF) of a generic velocity gradient field ∇u is exploited to expose the structures of flows, in particular, our field decomposition resulting in two vorticities with only mutual linkage as the topological content of the global helicity (accordingly decomposed into two equal parts). The local transformation to the RSF may indicate alternative (co)rotating frame(s) for specifying the objective argument(s) of the constitutive equation. When ∇u is uniformly of RSF in a fixed Cartesian coordinate frame, i.e., ux = ux(x, y) and uy = uy(x, y), but uz = uz(x, y, z), the model, with the decomposed vorticities both frozen-in to u, is for two-component-two-dimensional-coupled-with-one-component-three-dimensional flows in between two-dimensional-three-component (2D3C) and fully three-dimensional-three-component ones and may help curing the pathology in the helical 2D3C absolute equilibrium, making the latter effectively work in more realistic situations.

Dynamic motion analysis of dart throwers motion visualized through computerized tomography and calculation of the axis of rotation.

PubMed

Edirisinghe, Y; Troupis, J M; Patel, M; Smith, J; Crossett, M

2014-05-01

We used a dynamic three-dimensional (3D) mapping method to model the wrist in dynamic unrestricted dart throwers motion in three men and four women. With the aid of precision landmark identification, a 3D coordinate system was applied to the distal radius and the movement of the carpus was described. Subsequently, with dynamic 3D reconstructions and freedom to position the camera viewpoint anywhere in space, we observed the motion pathways of all carpal bones in dart throwers motion and calculated its axis of rotation. This was calculated to lie in 27° of anteversion from the coronal plane and 44° of varus angulation relative to the transverse plane. This technique is a safe and a feasible carpal imaging method to gain key information for decision making in future hand surgical and rehabilitative practices.

Analysis of the Material Properties of Early Chondrogenic Differentiated Adipose-Derived Stromal Cells (ASC) Using an in vitro Three-dimensional Micromass Culture System

PubMed Central

Xu, Yue; Balooch, Guive; Chiou, Michael; Bekerman, Elena; Ritchie, Robert O.; Longaker, Michael T.

2009-01-01

Cartilage is an avascular tissue with only a limited potential to heal and chondrocytes in vitro have poor proliferative capacity. Recently, adipose-derived stromal cells (ASC) have demonstrated a great potential for application to tissue engineering due to their ability to differentiate into cartilage, bone, and fat. In this study, we have utilized a high density three-dimensional (3D) micromass model system of early chondrogenesis with ASC. The material properties of these micromasses showed a significant increase in dynamic and static elastic modulus during the early chondrogenic differentiation process. These data suggest that the 3D micromass culture system represents an in vitro model of early chondrogenesis with dynamic cell signaling interactions associated with the mechanical properties of chondrocyte differentiation. PMID:17543281

Analysis of the material properties of early chondrogenic differentiated adipose-derived stromal cells (ASC) using an in vitro three-dimensional micromass culture system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Yue; Balooch, Guive; Chiou, Michael

2007-07-27

Cartilage is an avascular tissue with only a limited potential to heal and chondrocytes in vitro have poor proliferative capacity. Recently, adipose-derived stromal cells (ASC) have demonstrated a great potential for application to tissue engineering due to their ability to differentiate into cartilage, bone, and fat. In this study, we have utilized a high density three-dimensional (3D) micromass model system of early chondrogenesis with ASC. The material properties of these micromasses showed a significant increase in dynamic and static elastic modulus during the early chondrogenic differentiation process. These data suggest that the 3D micromass culture system represents an in vitromore » model of early chondrogenesis with dynamic cell signaling interactions associated with the mechanical properties of chondrocyte differentiation.« less

Pulse Phase Dynamic Thermal Tomography Investigation on the Defects of the Solid-Propellant Missile Engine Cladding Layer

NASA Astrophysics Data System (ADS)

Peng, Wei; Wang, Fei; Liu, Jun-yan; Xiao, Peng; Wang, Yang; Dai, Jing-min

2018-04-01

Pulse phase dynamic thermal tomography (PP-DTT) was introduced as a nondestructive inspection technique to detect the defects of the solid-propellant missile engine cladding layer. One-dimensional thermal wave mathematical model stimulated by pulse signal was developed and employed to investigate the thermal wave transmission characteristics. The pulse phase algorithm was used to extract the thermal wave characteristic of thermal radiation. Depth calibration curve was obtained by fuzzy c-means algorithm. Moreover, PP-DTT, a depth-resolved photothermal imaging modality, was employed to enable three-dimensional (3D) visualization of cladding layer defects. The comparison experiment between PP-DTT and classical dynamic thermal tomography was investigated. The results showed that PP-DTT can reconstruct the 3D topography of defects in a high quality.

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 emerging field of fully resolved, highly detailed 3D-modeling approaches. We present the developed general framework for 1D/3D hybrid modeling and apply it to investigate electrically active neurons and their intracellular spatio-temporal calcium dynamics.

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 the emerging field of fully resolved, highly detailed 3D-modeling approaches. We present the developed general framework for 1D/3D hybrid modeling and apply it to investigate electrically active neurons and their intracellular spatio-temporal calcium dynamics. PMID:25120463

Fluctuations and symmetries in two-dimensional active gels.

PubMed

Sarkar, N; Basu, A

2011-04-01

Motivated by the unique physical properties of biological active matter, e.g., cytoskeletal dynamics in eukaryotic cells, we set up effective two-dimensional (2d) coarse-grained hydrodynamic equations for the dynamics of thin active gels with polar or nematic symmetries. We use the well-known three-dimensional (3d) descriptions (K. Kruse et al., Eur. Phys. J. E 16, 5 (2005); A. Basu et al., Eur. Phys. J. E 27, 149 (2008)) for thin active-gel samples confined between parallel plates with appropriate boundary conditions to derive the effective 2d constitutive relations between appropriate thermodynamic fluxes and generalised forces for small deviations from equilibrium. We consider three distinct cases, characterised by spatial symmetries and boundary conditions, and show how such considerations dictate the structure of the constitutive relations. We use these to study the linear instabilities, calculate the correlation functions and the diffusion constant of a small tagged particle, and elucidate their dependences on the activity or nonequilibrium drive.

Generalized thick strip modelling for vortex-induced vibration of long flexible cylinders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bao, Y., E-mail: ybao@sjtu.edu.cn; Department of Aeronautics, Imperial College London, South Kensington Campus, London; Palacios, R., E-mail: r.palacios@imperial.ac.uk

2016-09-15

We propose a generalized strip modelling method that is computationally efficient for the VIV prediction of long flexible cylinders in three-dimensional incompressible flow. In order to overcome the shortcomings of conventional strip-theory-based 2D models, the fluid domain is divided into “thick” strips, which are sufficiently thick to locally resolve the small scale turbulence effects and three dimensionality of the flow around the cylinder. An attractive feature of the model is that we independently construct a three-dimensional scale resolving model for individual strips, which have local spanwise scale along the cylinder's axial direction and are only coupled through the structural modelmore » of the cylinder. Therefore, this approach is able to cover the full spectrum for fully resolved 3D modelling to 2D strip theory. The connection between these strips is achieved through the calculation of a tensioned beam equation, which is used to represent the dynamics of the flexible body. In the limit, however, a single “thick” strip would fill the full 3D domain. A parallel Fourier spectral/hp element method is employed to solve the 3D flow dynamics in the strip-domain, and then the VIV response prediction is achieved through the strip–structure interactions. Numerical tests on both laminar and turbulent flows as well as the comparison against the fully resolved DNS are presented to demonstrate the applicability of this approach.« less

Capturing method for integral three-dimensional imaging using multiviewpoint robotic cameras

NASA Astrophysics Data System (ADS)

Ikeya, Kensuke; Arai, Jun; Mishina, Tomoyuki; Yamaguchi, Masahiro

2018-03-01

Integral three-dimensional (3-D) technology for next-generation 3-D television must be able to capture dynamic moving subjects with pan, tilt, and zoom camerawork as good as in current TV program production. We propose a capturing method for integral 3-D imaging using multiviewpoint robotic cameras. The cameras are controlled through a cooperative synchronous system composed of a master camera controlled by a camera operator and other reference cameras that are utilized for 3-D reconstruction. When the operator captures a subject using the master camera, the region reproduced by the integral 3-D display is regulated in real space according to the subject's position and view angle of the master camera. Using the cooperative control function, the reference cameras can capture images at the narrowest view angle that does not lose any part of the object region, thereby maximizing the resolution of the image. 3-D models are reconstructed by estimating the depth from complementary multiviewpoint images captured by robotic cameras arranged in a two-dimensional array. The model is converted into elemental images to generate the integral 3-D images. In experiments, we reconstructed integral 3-D images of karate players and confirmed that the proposed method satisfied the above requirements.

A Head in Virtual Reality: Development of A Dynamic Head and Neck Model

ERIC Educational Resources Information Center

Nguyen, Ngan; Wilson, Timothy D.

2009-01-01

Advances in computer and interface technologies have made it possible to create three-dimensional (3D) computerized models of anatomical structures for visualization, manipulation, and interaction in a virtual 3D environment. In the past few decades, a multitude of digital models have been developed to facilitate complex spatial learning of the…

3D visualization of unsteady 2D airplane wake vortices

NASA Technical Reports Server (NTRS)

Ma, Kwan-Liu; Zheng, Z. C.

1994-01-01

Air flowing around the wing tips of an airplane forms horizontal tornado-like vortices that can be dangerous to following aircraft. The dynamics of such vortices, including ground and atmospheric effects, can be predicted by numerical simulation, allowing the safety and capacity of airports to be improved. In this paper, we introduce three-dimensional techniques for visualizing time-dependent, two-dimensional wake vortex computations, and the hazard strength of such vortices near the ground. We describe a vortex core tracing algorithm and a local tiling method to visualize the vortex evolution. The tiling method converts time-dependent, two-dimensional vortex cores into three-dimensional vortex tubes. Finally, a novel approach calculates the induced rolling moment on the following airplane at each grid point within a region near the vortex tubes and thus allows three-dimensional visualization of the hazard strength of the vortices. We also suggest ways of combining multiple visualization methods to present more information simultaneously.

Two-dimensional and three-dimensional dynamic imaging of live biofilms in a microchannel by time-of-flight secondary ion mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hua, Xin; Marshall, Matthew J.; Xiong, Yijia

2015-05-01

A vacuum compatible microfluidic reactor, SALVI (System for Analysis at the Liquid Vacuum Interface) was employed for in situ chemical imaging of live biofilms using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Depth profiling by sputtering materials in sequential layers resulted in live biofilm spatial chemical mapping. 2D images were reconstructed to report the first 3D images of hydrated biofilm elucidating spatial and chemical heterogeneity. 2D image principal component analysis (PCA) was conducted among biofilms at different locations in the microchannel. Our approach directly visualized spatial and chemical heterogeneity within the living biofilm by dynamic liquid ToF-SIMS.

3D culture models of tissues under tension.

PubMed

Eyckmans, Jeroen; Chen, Christopher S

2017-01-01

Cells dynamically assemble and organize into complex tissues during development, and the resulting three-dimensional (3D) arrangement of cells and their surrounding extracellular matrix in turn feeds back to regulate cell and tissue function. Recent advances in engineered cultures of cells to model 3D tissues or organoids have begun to capture this dynamic reciprocity between form and function. Here, we describe the underlying principles that have advanced the field, focusing in particular on recent progress in using mechanical constraints to recapitulate the structure and function of musculoskeletal tissues. © 2017. Published by The Company of Biologists Ltd.

Lack of robustness of textural measures obtained from 3D brain tumor MRIs impose a need for standardization

PubMed Central

Pérez-Beteta, Julián; Martínez-González, Alicia; Martino, Juan; Velasquez, Carlos; Arana, Estanislao; Pérez-García, Víctor M.

2017-01-01

Purpose Textural measures have been widely explored as imaging biomarkers in cancer. However, their robustness under dynamic range and spatial resolution changes in brain 3D magnetic resonance images (MRI) has not been assessed. The aim of this work was to study potential variations of textural measures due to changes in MRI protocols. Materials and methods Twenty patients harboring glioblastoma with pretreatment 3D T1-weighted MRIs were included in the study. Four different spatial resolution combinations and three dynamic ranges were studied for each patient. Sixteen three-dimensional textural heterogeneity measures were computed for each patient and configuration including co-occurrence matrices (CM) features and run-length matrices (RLM) features. The coefficient of variation was used to assess the robustness of the measures in two series of experiments corresponding to (i) changing the dynamic range and (ii) changing the matrix size. Results No textural measures were robust under dynamic range changes. Entropy was the only textural feature robust under spatial resolution changes (coefficient of variation under 10% in all cases). Conclusion Textural measures of three-dimensional brain tumor images are not robust neither under dynamic range nor under matrix size changes. Standards should be harmonized to use textural features as imaging biomarkers in radiomic-based studies. The implications of this work go beyond the specific tumor type studied here and pose the need for standardization in textural feature calculation of oncological images. PMID:28586353

One Dimensional(1D)-to-2D Crossover of Spin Correlations in the 3D Magnet ZnMn 2O 4

DOE PAGES

Disseler, S. M.; Chen, Y.; Yeo, S.; ...

2015-12-08

In this paper we report on the intriguing evolution of the dynamical spin correlations of the frustrated spinel ZnMn 2O 4. Inelastic neutron scattering and magnetization studies reveal that the dynamical correlations at high temperatures are 1D. At lower temperature, these dynamical correlations become 2D. Surprisingly, the dynamical correlations condense into a quasi 2D Ising-like ordered state, making this a rare observation of two dimensional order on the spinel lattice. Remarkably, 3D ordering is not observed down to temperatures as low as 300 mK. This unprecedented dimensional crossover stems from frustrated exchange couplings due to the huge Jahn-Teller distortions aroundmore » Mn 3+ ions on the spinel lattice.« less

4D Biofabrication of Branching Multicellular Structures: A Morphogenesis Simulation Based on Turing’s Reaction-Diffusion Dynamics

NASA Astrophysics Data System (ADS)

Zhu, Xiaolu; Yang, Hao

2017-12-01

The recently emerged four-dimensional (4D) biofabrication technique aims to create dynamic three-dimensional (3D) biological structures that can transform their shapes or functionalities with time when an external stimulus is imposed or when cell postprinting self-assembly occurs. The evolution of 3D pattern of branching geometry via self-assembly of cells is critical for 4D biofabrication of artificial organs or tissues with branched geometry. However, it is still unclear that how the formation and evolution of these branching pattern are biologically encoded. We study the 4D fabrication of lung branching structures utilizing a simulation model on the reaction-diffusion mechanism, which is established using partial differential equations of four variables, describing the reaction and diffusion process of morphogens with time during the development process of lung branching. The simulation results present the forming process of 3D branching pattern, and also interpret the behaviors of side branching and tip splitting as the stalk growing, through 3D visualization of numerical simulation.

Multidimensional immunolabeling and 4D time-lapse imaging of vital ex vivo lung tissue

PubMed Central

Vierkotten, Sarah; Lindner, Michael; Königshoff, Melanie; Eickelberg, Oliver

2015-01-01

During the last decades, the study of cell behavior was largely accomplished in uncoated or extracellular matrix (ECM)-coated plastic dishes. To date, considerable cell biological efforts have tried to model in vitro the natural microenvironment found in vivo. For the lung, explants cultured ex vivo as lung tissue cultures (LTCs) provide a three-dimensional (3D) tissue model containing all cells in their natural microenvironment. Techniques for assessing the dynamic live interaction between ECM and cellular tissue components, however, are still missing. Here, we describe specific multidimensional immunolabeling of living 3D-LTCs, derived from healthy and fibrotic mouse lungs, as well as patient-derived 3D-LTCs, and concomitant real-time four-dimensional multichannel imaging thereof. This approach allowed the evaluation of dynamic interactions between mesenchymal cells and macrophages with their ECM. Furthermore, fibroblasts transiently expressing focal adhesions markers incorporated into the 3D-LTCs, paving new ways for studying the dynamic interaction between cellular adhesions and their natural-derived ECM. A novel protein transfer technology (FuseIt/Ibidi) shuttled fluorescently labeled α-smooth muscle actin antibodies into the native cells of living 3D-LTCs, enabling live monitoring of α-smooth muscle actin-positive stress fibers in native tissue myofibroblasts residing in fibrotic lesions of 3D-LTCs. Finally, this technique can be applied to healthy and diseased human lung tissue, as well as to adherent cells in conventional two-dimensional cell culture. This novel method will provide valuable new insights into the dynamics of ECM (patho)biology, studying in detail the interaction between ECM and cellular tissue components in their natural microenvironment. PMID:26092995

3DSDSCAR--a three dimensional structural database for sialic acid-containing carbohydrates through molecular dynamics simulation.

PubMed

Veluraja, Kasinadar; Selvin, Jeyasigamani F A; Venkateshwari, Selvakumar; Priyadarzini, Thanu R K

2010-09-23

The inherent flexibility and lack of strong intramolecular interactions of oligosaccharides demand the use of theoretical methods for their structural elucidation. In spite of the developments of theoretical methods, not much research on glycoinformatics is done so far when compared to bioinformatics research on proteins and nucleic acids. We have developed three dimensional structural database for a sialic acid-containing carbohydrates (3DSDSCAR). This is an open-access database that provides 3D structural models of a given sialic acid-containing carbohydrate. At present, 3DSDSCAR contains 60 conformational models, belonging to 14 different sialic acid-containing carbohydrates, deduced through 10 ns molecular dynamics (MD) simulations. The database is available at the URL: http://www.3dsdscar.org. Copyright 2010 Elsevier Ltd. All rights reserved.

Inertia-dependent dynamics of three-dimensional vesicles and red blood cells in shear flow.

PubMed

Luo, Zheng Yuan; Wang, Shu Qi; He, Long; Xu, Feng; Bai, Bo Feng

2013-10-28

A three-dimensional (3D) simulation study of the effect of inertia on the dynamics of vesicles and red blood cells (RBCs) has not been reported. Here, we developed a 3D model based on the front tracking method to investigate how inertia affects the dynamics of spherical/non-spherical vesicles and biconcave-shaped RBCs with the Reynolds number ranging from 0.1 to 10. The results showed that inertia induced non-spherical vesicles transitioned from tumbling to swinging, which was not observed in previous 2D models. The critical viscosity ratio of inner/outer fluids for the tumbling–swinging transition remarkably increased with an increasing Reynolds number. The deformation of vesicles was greatly enhanced by inertia, and the frequency of tumbling and tank-treading was significantly decreased by inertia. We also found that RBCs can transit from tumbling to steady tank-treading through the swinging regime when the Reynolds number increased from 0.1 to 10. These results indicate that inertia needs to be considered at moderate Reynolds number (Re ~ 1) in the study of blood flow in the human body and the flow of deformable particle suspension in inertial microfluidic devices. The developed 3D model provided new insights into the dynamics of RBCs under shear flow, thus holding great potential to better understand blood flow behaviors under normal/disease conditions.

Optimal management of reconfigurable manufacturing system modeling with Petri nets developed three-dimensional - RPD3D

NASA Astrophysics Data System (ADS)

Teodor, F.; Marinescu, V.; Epureanu, A.

2016-11-01

Modeling of reconfigurable manufacturing systems would have done using existing Petri net types, but the complexity and dynamics of the new manufacturing system, mainly data reconfiguration feature, required looking for a more compact representation with many variables that to model as accurately not only the normal operation of the production system but can capture and model and reconfiguration process. Thus, it was necessary to create a new class of Petri nets, called RPD3D (Developed Petri nets with three dimensional) showing the name of both lineage (new class derived from Petri nets developed, created in 2000 by Prof. Dr. Ing Vasile Marinescu in his doctoral thesis) [1], but the most important of the new features defining (transformation from one 2D model into a 3D model).The idea was to introduce the classical model of a Petri third dimension to be able to overlay multiple levels (layers) formed in 2D or 3D Petri nets that interact with each other (receiving or giving commands to enable or disable the various modules together simulating the operation of reconfigurable manufacturing systems). The aim is to present a new type of Petri nets called RPD3D - Developed Petri three-dimensional model used for optimal control and simulation of reconfigurable manufacturing systems manufacture of products such systems.

The performance analysis of three-dimensional track-before-detect algorithm based on Fisher-Tippett-Gnedenko theorem

NASA Astrophysics Data System (ADS)

Cho, Hoonkyung; Chun, Joohwan; Song, Sungchan

2016-09-01

The dim moving target tracking from the infrared image sequence in the presence of high clutter and noise has been recently under intensive investigation. The track-before-detect (TBD) algorithm processing the image sequence over a number of frames before decisions on the target track and existence is known to be especially attractive in very low SNR environments (⩽ 3 dB). In this paper, we shortly present a three-dimensional (3-D) TBD with dynamic programming (TBD-DP) algorithm using multiple IR image sensors. Since traditional two-dimensional TBD algorithm cannot track and detect the along the viewing direction, we use 3-D TBD with multiple sensors and also strictly analyze the detection performance (false alarm and detection probabilities) based on Fisher-Tippett-Gnedenko theorem. The 3-D TBD-DP algorithm which does not require a separate image registration step uses the pixel intensity values jointly read off from multiple image frames to compute the merit function required in the DP process. Therefore, we also establish the relationship between the pixel coordinates of image frame and the reference coordinates.

Design and Implementation of High-Performance GIS Dynamic Objects Rendering Engine

NASA Astrophysics Data System (ADS)

Zhong, Y.; Wang, S.; Li, R.; Yun, W.; Song, G.

2017-12-01

Spatio-temporal dynamic visualization is more vivid than static visualization. It important to use dynamic visualization techniques to reveal the variation process and trend vividly and comprehensively for the geographical phenomenon. To deal with challenges caused by dynamic visualization of both 2D and 3D spatial dynamic targets, especially for different spatial data types require high-performance GIS dynamic objects rendering engine. The main approach for improving the rendering engine with vast dynamic targets relies on key technologies of high-performance GIS, including memory computing, parallel computing, GPU computing and high-performance algorisms. In this study, high-performance GIS dynamic objects rendering engine is designed and implemented for solving the problem based on hybrid accelerative techniques. The high-performance GIS rendering engine contains GPU computing, OpenGL technology, and high-performance algorism with the advantage of 64-bit memory computing. It processes 2D, 3D dynamic target data efficiently and runs smoothly with vast dynamic target data. The prototype system of high-performance GIS dynamic objects rendering engine is developed based SuperMap GIS iObjects. The experiments are designed for large-scale spatial data visualization, the results showed that the high-performance GIS dynamic objects rendering engine have the advantage of high performance. Rendering two-dimensional and three-dimensional dynamic objects achieve 20 times faster on GPU than on CPU.

Shear-wave elasticity measurements of three-dimensional cell cultures for mechanobiology

PubMed Central

Kuo, Po-Ling; Charng, Ching-Che; Wu, Po-Chen

2017-01-01

ABSTRACT Studying mechanobiology in three-dimensional (3D) cell cultures better recapitulates cell behaviors in response to various types of mechanical stimuli in vivo. Stiffening of the extracellular matrix resulting from cell remodeling potentiates many pathological conditions, including advanced cancers. However, an effective tool for measuring the spatiotemporal changes in elastic properties of such 3D cell cultures without directly contacting the samples has not been reported previously. We describe an ultrasonic shear-wave-based platform for quantitatively evaluating the spatiotemporal dynamics of the elasticity of a matrix remodeled by cells cultured in 3D environments. We used this approach to measure the elasticity changes of 3D matrices grown with highly invasive lung cancer cells and cardiac myoblasts, and to delineate the principal mechanism underlying the stiffening of matrices remodeled by these cells. The described approach can be a useful tool in fields investigating and manipulating the mechanotransduction of cells in 3D contexts, and also has potential as a drug-screening platform. PMID:27505887

Operating scheme for the light-emitting diode array of a volumetric display that exhibits multiple full-color dynamic images

NASA Astrophysics Data System (ADS)

Hirayama, Ryuji; Shiraki, Atsushi; Nakayama, Hirotaka; Kakue, Takashi; Shimobaba, Tomoyoshi; Ito, Tomoyoshi

2017-07-01

We designed and developed a control circuit for a three-dimensional (3-D) light-emitting diode (LED) array to be used in volumetric displays exhibiting full-color dynamic 3-D images. The circuit was implemented on a field-programmable gate array; therefore, pulse-width modulation, which requires high-speed processing, could be operated in real time. We experimentally evaluated the developed system by measuring the luminance of an LED with varying input and confirmed that the system works appropriately. In addition, we demonstrated that the volumetric display exhibits different full-color dynamic two-dimensional images in two orthogonal directions. Each of the exhibited images could be obtained only from the prescribed viewpoint. Such directional characteristics of the system are beneficial for applications, including digital signage, security systems, art, and amusement.

The 3-dimensional cellular automata for HIV infection

NASA Astrophysics Data System (ADS)

Mo, Youbin; Ren, Bin; Yang, Wencao; Shuai, Jianwei

2014-04-01

The HIV infection dynamics is discussed in detail with a 3-dimensional cellular automata model in this paper. The model can reproduce the three-phase development, i.e., the acute period, the asymptotic period and the AIDS period, observed in the HIV-infected patients in a clinic. We show that the 3D HIV model performs a better robustness on the model parameters than the 2D cellular automata. Furthermore, we reveal that the occurrence of a perpetual source to successively generate infectious waves to spread to the whole system drives the model from the asymptotic state to the AIDS state.

Software Aids In Graphical Depiction Of Flow Data

NASA Technical Reports Server (NTRS)

Stegeman, J. D.

1995-01-01

Interactive Data Display System (IDDS) computer program is graphical-display program designed to assist in visualization of three-dimensional flow in turbomachinery. Grid and simulation data files in PLOT3D format required for input. Able to unwrap volumetric data cone associated with centrifugal compressor and display results in easy-to-understand two- or three-dimensional plots. IDDS provides majority of visualization and analysis capability for Integrated Computational Fluid Dynamics and Experiment (ICE) system. IDDS invoked from any subsystem, or used as stand-alone package of display software. Generates contour, vector, shaded, x-y, and carpet plots. Written in C language. Input file format used by IDDS is that of PLOT3D (COSMIC item ARC-12782).

Surprising loss of three-dimensionality in low-energy spin correlations on approaching superconductivity in Fe1 +yTe1 -xSex

NASA Astrophysics Data System (ADS)

Xu, Zhijun; Schneeloch, J. A.; Wen, Jinsheng; Winn, B. L.; Granroth, G. E.; Zhao, Yang; Gu, Genda; Zaliznyak, Igor; Tranquada, J. M.; Birgeneau, R. J.; Xu, Guangyong

2017-10-01

We report inelastic neutron scattering measurements of low-energy (ℏ ω ≲10 meV) magnetic excitations in the "11" system Fe1 +yTe1 -xSex . The spin correlations are two-dimensional (2D) in the superconducting samples at low temperature, but appear much more three-dimensional (3D) when the temperature rises well above Tc˜15 K, with a clear increase of the (dynamic) spin correlation length perpendicular to the Fe planes. This behavior is extremely unusual; typically, the suppression of thermal fluctuations at low temperature would favor the enhancement of 3D correlations, or even ordering, and the reversion to 2D cannot be naturally explained when only the spin degree of freedom is considered. Our results suggest that the low temperature physics in the 11 system, in particular the evolution of low-energy spin excitations towards superconducting pairing, intrinsically involves changes in orbital correlations.

Breast segmentation in MR images using three-dimensional spiral scanning and dynamic programming

NASA Astrophysics Data System (ADS)

Jiang, Luan; Lian, Yanyun; Gu, Yajia; Li, Qiang

2013-03-01

Magnetic resonance (MR) imaging has been widely used for risk assessment and diagnosis of breast cancer in clinic. To develop a computer-aided diagnosis (CAD) system, breast segmentation is the first important and challenging task. The accuracy of subsequent quantitative measurement of breast density and abnormalities depends on accurate definition of the breast area in the images. The purpose of this study is to develop and evaluate a fully automated method for accurate segmentation of breast in three-dimensional (3-D) MR images. A fast method was developed to identify bounding box, i.e., the volume of interest (VOI), for breasts. A 3-D spiral scanning method was used to transform the VOI of each breast into a single two-dimensional (2-D) generalized polar-coordinate image. Dynamic programming technique was applied to the transformed 2-D image for delineating the "optimal" contour of the breast. The contour of the breast in the transformed 2-D image was utilized to reconstruct the segmentation results in the 3-D MR images using interpolation and lookup table. The preliminary results on 17 cases show that the proposed method can obtain accurate segmentation of the breast based on subjective observation. By comparing with the manually delineated region of 16 breasts in 8 cases, an overlap index of 87.6% +/- 3.8% (mean +/- SD), and a volume agreement of 93.4% +/- 4.5% (mean +/- SD) were achieved, respectively. It took approximately 3 minutes for our method to segment the breast in an MR scan of 256 slices.

On-line observation of cell growth in a three-dimensional matrix on surface-modified microelectrode arrays.

PubMed

Lin, Shu-Ping; Kyriakides, Themis R; Chen, Jia-Jin J

2009-06-01

Despite many successful applications of microelectrode arrays (MEAs), typical two-dimensional in-vitro cultures do not project the full scale of the cell growth environment in the three-dimensional (3D) in-vivo setting. This study aims to on-line monitor in-vitro cell growth in a 3D matrix on the surface-modified MEAs with a dynamic perfusion culture system. A 3D matrix consisting of poly(ethylene glycol) hydrogel supplemented with poly-D-lysine was subsequently synthesized in situ on the self-assembled monolayer modified MEAs. FTIR spectrum analysis revealed a peak at 2100 cm(-1) due to the degradation of the structure of the 3D matrix. After 2 wks, microscopic examination revealed that the non-degraded area was around 1500 microm(2) and provided enough space for cell growth. Fluorescence microscopy revealed that the degraded 3D matrix was non-cytotoxic allowing the growth of NIH3T3 fibroblasts and cortical neurons in vitro. Time-course changes of total impedance including resistance and reactance were recorded for 8 days to evaluate the cell growth in the 3D matrix on the MEA. A consistent trend reflecting changes of reactance and total impedance was observed. These in-vitro assays demonstrate that our 3D matrix can construct a biomimetic system for cell growth and analysis of cell surface interactions.

Three-body problem in d-dimensional space: Ground state, (quasi)-exact-solvability

NASA Astrophysics Data System (ADS)

Turbiner, Alexander V.; Miller, Willard; Escobar-Ruiz, M. A.

2018-02-01

As a straightforward generalization and extension of our previous paper [A. V. Turbiner et al., "Three-body problem in 3D space: Ground state, (quasi)-exact-solvability," J. Phys. A: Math. Theor. 50, 215201 (2017)], we study the aspects of the quantum and classical dynamics of a 3-body system with equal masses, each body with d degrees of freedom, with interaction depending only on mutual (relative) distances. The study is restricted to solutions in the space of relative motion which are functions of mutual (relative) distances only. It is shown that the ground state (and some other states) in the quantum case and the planar trajectories (which are in the interaction plane) in the classical case are of this type. The quantum (and classical) Hamiltonian for which these states are eigenfunctions is derived. It corresponds to a three-dimensional quantum particle moving in a curved space with special d-dimension-independent metric in a certain d-dependent singular potential, while at d = 1, it elegantly degenerates to a two-dimensional particle moving in flat space. It admits a description in terms of pure geometrical characteristics of the interaction triangle which is defined by the three relative distances. The kinetic energy of the system is d-independent; it has a hidden sl(4, R) Lie (Poisson) algebra structure, alternatively, the hidden algebra h(3) typical for the H3 Calogero model as in the d = 3 case. We find an exactly solvable three-body S3-permutationally invariant, generalized harmonic oscillator-type potential as well as a quasi-exactly solvable three-body sextic polynomial type potential with singular terms. For both models, an extra first order integral exists. For d = 1, the whole family of 3-body (two-dimensional) Calogero-Moser-Sutherland systems as well as the Tremblay-Turbiner-Winternitz model is reproduced. It is shown that a straightforward generalization of the 3-body (rational) Calogero model to d > 1 leads to two primitive quasi-exactly solvable problems. The extension to the case of non-equal masses is straightforward and is briefly discussed.

Ultrathin thermoresponsive self-folding 3D graphene

PubMed Central

Xu, Weinan; Qin, Zhao; Chen, Chun-Teh; Kwag, Hye Rin; Ma, Qinli; Sarkar, Anjishnu; Buehler, Markus J.; Gracias, David H.

2017-01-01

Graphene and other two-dimensional materials have unique physical and chemical properties of broad relevance. It has been suggested that the transformation of these atomically planar materials to three-dimensional (3D) geometries by bending, wrinkling, or folding could significantly alter their properties and lead to novel structures and devices with compact form factors, but strategies to enable this shape change remain limited. We report a benign thermally responsive method to fold and unfold monolayer graphene into predesigned, ordered 3D structures. The methodology involves the surface functionalization of monolayer graphene using ultrathin noncovalently bonded mussel-inspired polydopamine and thermoresponsive poly(N-isopropylacrylamide) brushes. The functionalized graphene is micropatterned and self-folds into ordered 3D structures with reversible deformation under a full control by temperature. The structures are characterized using spectroscopy and microscopy, and self-folding is rationalized using a multiscale molecular dynamics model. Our work demonstrates the potential to design and fabricate ordered 3D graphene structures with predictable shape and dynamics. We highlight applicability by encapsulating live cells and creating nonlinear resistor and creased transistor devices. PMID:28989963

Biodynamic profiling of three-dimensional tissue growth techniques

NASA Astrophysics Data System (ADS)

Sun, Hao; Merrill, Dan; Turek, John; Nolte, David

2016-03-01

Three-dimensional tissue culture presents a more biologically relevant environment in which to perform drug development than conventional two-dimensional cell culture. However, obtaining high-content information from inside three dimensional tissue has presented an obstacle to rapid adoption of 3D tissue culture for pharmaceutical applications. Biodynamic imaging is a high-content three-dimensional optical imaging technology based on low-coherence interferometry and digital holography that uses intracellular dynamics as high-content image contrast. In this paper, we use biodynamic imaging to compare pharmaceutical responses to Taxol of three-dimensional multicellular spheroids grown by three different growth techniques: rotating bioreactor, hanging-drop and plate-grown spheroids. The three growth techniques have systematic variations among tissue cohesiveness and intracellular activity and consequently display different pharmacodynamics under identical drug dose conditions. The in vitro tissue cultures are also compared to ex vivo living biopsies. These results demonstrate that three-dimensional tissue cultures are not equivalent, and that drug-response studies must take into account the growth method.

Impact of Basal Hydrology Near Grounding Lines: Results from the MISMIP-3D and MISMIP+ Experiments Using the Community Ice Sheet Model

NASA Astrophysics Data System (ADS)

Leguy, G.; Lipscomb, W. H.; Asay-Davis, X.

2017-12-01

Ice sheets and ice shelves are linked by the transition zone, the region where the grounded ice lifts off the bedrock and begins to float. Adequate resolution of the transition zone is necessary for numerically accurate ice sheet-ice shelf simulations. In previous work we have shown that by using a simple parameterization of the basal hydrology, a smoother transition in basal water pressure between floating and grounded ice improves the numerical accuracy of a one-dimensional vertically integrated fixed-grid model. We used a set of experiments based on the Marine Ice Sheet Model Intercomparison Project (MISMIP) to show that reliable grounding-line dynamics at resolutions 1 km is achievable. In this presentation we use the Community Ice Sheet Model (CISM) to demonstrate how the representation of basal lubrication impacts three-dimensional models using the MISMIP-3D and MISMIP+ experiments. To this end we will compare three different Stokes approximations: the Shallow Shelf Approximation (SSA), a depth-integrated higher-order approximation, and the Blatter-Pattyn model. The results from our one-dimensional model carry over to the 3-D models; a resolution of 1 km (and in some cases 2 km) remains sufficient to accurately simulate grounding-line dynamics.

Atom-based 3D-QSAR, induced fit docking, and molecular dynamics simulations study of thieno[2,3-b]pyridines negative allosteric modulators of mGluR5.

PubMed

Vijaya Prabhu, Sitrarasu; Singh, Sanjeev Kumar

2018-05-28

Atom-based three dimensional-quantitative structure-activity relationship (3D-QSAR) model was developed on the basis of 5-point pharmacophore hypothesis (AARRR) with two hydrogen bond acceptors (A) and three aromatic rings for the derivatives of thieno[2,3-b]pyridine, which modulates the activity to inhibit the mGluR5 receptor. Generation of a highly predictive 3D-QSAR model was performed using the alignment of predicted pharmacophore hypothesis for the training set (R 2  = 0.84, SD = 0.26, F = 45.8, N = 29) and test set (Q 2  = 0.74, RMSE = 0.235, Pearson-R = 0.94, N = 9). The best pharmacophore hypothesis AARRR was selected, and developed three dimensional-quantitative structure activity relationship (3D-QSAR) model also supported the outcome of this study by means of favorable and unfavorable electron withdrawing group and hydrophobic regions of most active compound 42d and least active compound 18b. Following, induced fit docking and binding free energy calculations reveals the reliable binding orientation of the compounds. Finally, molecular dynamics simulations for 100 ns were performed to depict the protein-ligand stability. We anticipate that the resulted outcome could be supportive to discover potent negative allosteric modulators for metabotropic glutamate receptor 5 (mGluR5).

Effect of a Material Contrast on a Dynamic Rupture: 3-D

NASA Astrophysics Data System (ADS)

Harris, R. A.; Day, S. M.

2003-12-01

We use numerical simulations of spontaneously propagating ruptures to examine the effect of a material contrast on earthquake dynamics. We specifically study the case of a lateral contrast whereby the fault is the boundary between two different rock-types. This scenario was previously studied in two-dimensions by Harris and Day [BSSA, 1997], and Andrews and Ben-Zion [JGR, 1997], in addition to subsequent 2-D studies, but it has not been known if the two-dimensional results are applicable to the real three-dimensional world. The addition of the third dimension implies a transition from pure mode II (i.e., plane-strain) to mixed-mode crack dynamics, which is more complicated since in mode II the shear and normal stresses are coupled whereas in mode III (i.e., anti-plane strain) they are not coupled. We use a slip-weakening fracture criterion and examine the effect on an earthquake rupture of material contrasts of up to 50 percent across the fault zone. We find a surprisingly good agreement between our earlier 2-D results, and our 3-D results for along-strike propagation. We find that the analytical solution presented in Harris and Day [BSSA, 1997] does an excellent job at predicting the bilateral, along-strike rupture velocities for the three-dimensional situation. In contrast, the along-dip propagation behaves much as expected for a purely mode-III rupture, with the rupture velocities up-dip and down-dip showing the expected symmetries.

A Java tool for dynamic web-based 3D visualization of anatomy and overlapping gene or protein expression patterns.

PubMed

Gerth, Victor E; Vize, Peter D

2005-04-01

The Gene Expression Viewer is a web-launched three-dimensional visualization tool, tailored to compare surface reconstructions of multi-channel image volumes generated by confocal microscopy or micro-CT.

A neural network model of three-dimensional dynamic electron density in the inner magnetosphere

NASA Astrophysics Data System (ADS)

Chu, X.; Bortnik, J.; Li, W.; Ma, Q.; Denton, R.; Yue, C.; Angelopoulos, V.; Thorne, R. M.; Darrouzet, F.; Ozhogin, P.; Kletzing, C. A.; Wang, Y.; Menietti, J.

2017-09-01

A plasma density model of the inner magnetosphere is important for a variety of applications including the study of wave-particle interactions, and wave excitation and propagation. Previous empirical models have been developed under many limiting assumptions and do not resolve short-term variations, which are especially important during storms. We present a three-dimensional dynamic electron density (DEN3D) model developed using a feedforward neural network with electron densities obtained from four satellite missions. The DEN3D model takes spacecraft location and time series of solar and geomagnetic indices (F10.7, SYM-H, and AL) as inputs. It can reproduce the observed density with a correlation coefficient of 0.95 and predict test data set with error less than a factor of 2. Its predictive ability on out-of-sample data is tested on field-aligned density profiles from the IMAGE satellite. DEN3D's predictive ability provides unprecedented opportunities to gain insight into the 3-D behavior of the inner magnetospheric plasma density at any time and location. As an example, we apply DEN3D to a storm that occurred on 1 June 2013. It successfully reproduces various well-known dynamic features in three dimensions, such as plasmaspheric erosion and recovery, as well as plume formation. Storm time long-term density variations are consistent with expectations; short-term variations appear to be modulated by substorm activity or enhanced convection, an effect that requires further study together with multispacecraft in situ or imaging measurements. Investigating plasmaspheric refilling with the model, we find that it is not monotonic in time and is more complex than expected from previous studies, deserving further attention.

Modeling of abnormal mechanical properties of nickel-based single crystal superalloy by three-dimensional discrete dislocation dynamics

NASA Astrophysics Data System (ADS)

Yang, Hui; Li, Zhenhuan; Huang, Minsheng

2014-12-01

Unlike common single crystals, the nickel-based single crystal superalloy shows surprisingly anomalous flow strength (i.e. with the increase of temperature, the yield strength first increases to a peak value and then decreases) and tension-compression (TC) asymmetry. A comprehensive three-dimensional discrete dislocation dynamics (3D-DDD) procedure was developed to model these abnormal mechanical properties. For this purpose, a series of complicated dynamic evolution details of Kear-Wilsdorf (KW) locks, which are closely related to the flow strength anomaly and TC asymmetry, were incorporated into this 3D-DDD framework. Moreover, the activation of the cubic slip system, which is the origin of the decrease in yield strength with increasing temperature at relatively high temperatures, was especially taken into account by introducing a competition criterion between the unlocking of the KW locks and the activation of the cubic slip system. To test our framework, a series of 3D-DDD simulations were performed on a representative volume cell model with a cuboidal Ni3Al precipitate phase embedded in a nickel matrix. Results show that the present 3D-DDD procedure can successfully capture the dynamic evolution of KW locks, the flow strength anomaly and TC asymmetry. Then, the underlying dislocation mechanisms leading to these abnormal mechanical responses were investigated and discussed in detail. Finally, a cyclic deformation of the nickel-based single crystal superalloy was modeled by using the present DDD model, with a special focus on the influence of KW locks on the Bauschinger effect and cyclic softening.

A three-dimensional insight into the complexity of flow convergence in mitral regurgitation: adjunctive benefit of anatomic regurgitant orifice area.

PubMed

Chandra, Sonal; Salgo, Ivan S; Sugeng, Lissa; Weinert, Lynn; Settlemier, Scott H; Mor-Avi, Victor; Lang, Roberto M

2011-09-01

Mitral effective regurgitant orifice area (EROA) using the flow convergence (FC) method is used to quantify the severity of mitral regurgitation (MR). However, it is challenging and prone to interobserver variability in complex valvular pathology. We hypothesized that real-time three-dimensional (3D) transesophageal echocardiography (RT3D TEE) derived anatomic regurgitant orifice area (AROA) can be a reasonable adjunct, irrespective of valvular geometry. Our goals were to 1) to determine the regurgitant orifice morphology and distance suitable for FC measurement using 3D computational flow dynamics and finite element analysis (FEA), and (2) to measure AROA from RT3D TEE and compare it with 2D FC derived EROA measurements. We studied 61 patients. EROA was calculated from 2D TEE images using the 2D-FC technique, and AROA was obtained from zoomed RT3DE TEE acquisitions using prototype software. 3D computational fluid dynamics by FEA were applied to 3D TEE images to determine the effects of mitral valve (MV) orifice geometry on FC pattern. 3D FEA analysis revealed that a central regurgitant orifice is suitable for FC measurements at an optimal distance from the orifice but complex MV orifice resulting in eccentric jets yielded nonaxisymmetric isovelocity contours close to the orifice where the assumptions underlying FC are problematic. EROA and AROA measurements correlated well (r = 0.81) with a nonsignificant bias. However, in patients with eccentric MR, the bias was larger than in central MR. Intermeasurement variability was higher for the 2D FC technique than for RT3DE-based measurements. With its superior reproducibility, 3D analysis of the AROA is a useful alternative to quantify MR when 2D FC measurements are challenging.

A study in three-dimensional chaotic dynamics: Granular flow and transport in a bi-axial spherical tumbler

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christov, Ivan C.; Lueptow, Richard M.; Ottino, Julio M.

We study three-dimensional (3D) chaotic dynamics through an analysis of transport in a granular flow in a half-full spherical tumbler rotated sequentially about two orthogonal axes (a bi-axial “blinking” tumbler). The flow is essentially quasi-two-dimensional in any vertical slice of the sphere during rotation about a single axis, and we provide an explicit exact solution to the model in this case. Hence, the cross-sectional flow can be represented by a twist map, allowing us to express the 3D flow as a linked twist map (LTM). We prove that if the rates of rotation about each axis are equal, then (inmore » the absence of stochasticity) particle trajectories are restricted to two-dimensional (2D) surfaces consisting of a portion of a hemispherical shell closed by a “cap''; if the rotation rates are unequal, then particles can leave the surface they start on and traverse a volume of the tumbler. The period-one structures of the governing LTM are examined in detail: analytical expressions are provided for the location of period-one curves, their extent into the bulk of the granular material, and their dependence on the protocol parameters (rates and durations of rotations). Exploiting the restriction of trajectories to 2D surfaces in the case of equal rotation rates about the axes, a method is proposed for identifying and constructing 3D Kolmogorov--Arnold--Moser (KAM) tubes around the normally elliptic period-one curves. The invariant manifold structure arising from the normally hyperbolic period-one curves is also examined. When the motion is restricted to 2D surfaces, the structure of manifolds of the hyperbolic points in the bulk differs from that corresponding to hyperbolic points in the flowing layer. Each is reminiscent of a template provided by a non-integrable perturbation to a Hamiltonian system, though the governing LTM is not. This highlights the novel 3D chaotic behaviors observed in this model dynamical system.« less

A study in three-dimensional chaotic dynamics: Granular flow and transport in a bi-axial spherical tumbler

DOE PAGES

Christov, Ivan C.; Lueptow, Richard M.; Ottino, Julio M.; ...

2014-05-22

We study three-dimensional (3D) chaotic dynamics through an analysis of transport in a granular flow in a half-full spherical tumbler rotated sequentially about two orthogonal axes (a bi-axial “blinking” tumbler). The flow is essentially quasi-two-dimensional in any vertical slice of the sphere during rotation about a single axis, and we provide an explicit exact solution to the model in this case. Hence, the cross-sectional flow can be represented by a twist map, allowing us to express the 3D flow as a linked twist map (LTM). We prove that if the rates of rotation about each axis are equal, then (inmore » the absence of stochasticity) particle trajectories are restricted to two-dimensional (2D) surfaces consisting of a portion of a hemispherical shell closed by a “cap''; if the rotation rates are unequal, then particles can leave the surface they start on and traverse a volume of the tumbler. The period-one structures of the governing LTM are examined in detail: analytical expressions are provided for the location of period-one curves, their extent into the bulk of the granular material, and their dependence on the protocol parameters (rates and durations of rotations). Exploiting the restriction of trajectories to 2D surfaces in the case of equal rotation rates about the axes, a method is proposed for identifying and constructing 3D Kolmogorov--Arnold--Moser (KAM) tubes around the normally elliptic period-one curves. The invariant manifold structure arising from the normally hyperbolic period-one curves is also examined. When the motion is restricted to 2D surfaces, the structure of manifolds of the hyperbolic points in the bulk differs from that corresponding to hyperbolic points in the flowing layer. Each is reminiscent of a template provided by a non-integrable perturbation to a Hamiltonian system, though the governing LTM is not. This highlights the novel 3D chaotic behaviors observed in this model dynamical system.« less

SubductionGenerator: A program to build three-dimensional plate configurations

NASA Astrophysics Data System (ADS)

Jadamec, M. A.; Kreylos, O.; Billen, M. I.; Turcotte, D. L.; Knepley, M.

2016-12-01

Geologic, geochemical, and geophysical data from subduction zones indicate that a two-dimensional paradigm for plate tectonic boundaries is no longer adequate to explain the observations. Many open source software packages exist to simulate the viscous flow of the Earth, such as the dynamics of subduction. However, there are few open source programs that generate the three-dimensional model input. We present an open source software program, SubductionGenerator, that constructs the three-dimensional initial thermal structure and plate boundary structure. A 3D model mesh and tectonic configuration are constructed based on a user specified model domain, slab surface, seafloor age grid file, and shear zone surface. The initial 3D thermal structure for the plates and mantle within the model domain is then constructed using a series of libraries within the code that use a half-space cooling model, plate cooling model, and smoothing functions. The code maps the initial 3D thermal structure and the 3D plate interface onto the mesh nodes using a series of libraries including a k-d tree to increase efficiency. In this way, complicated geometries and multiple plates with variable thickness can be built onto a multi-resolution finite element mesh with a 3D thermal structure and 3D isotropic shear zones oriented at any angle with respect to the grid. SubductionGenerator is aimed at model set-ups more representative of the earth, which can be particularly challenging to construct. Examples include subduction zones where the physical attributes vary in space, such as slab dip and temperature, and overriding plate temperature and thickness. Thus, the program can been used to construct initial tectonic configurations for triple junctions and plate boundary corners.

A novel two-dimensional dynamic anal ultrasonography technique to assess anismus comparing with three-dimensional echodefecography.

PubMed

Murad-Regadas, S M; Regadas, F S P; Barreto, R G L; Rodrigues, L V; de Souza, M H L P

2009-10-01

The aim of this prospective study was to test two-dimensional dynamic anorectal ultrasonography (2D-DAUS) in the assessment of anismus and compare it with echodefecography (ECD). Fifty consecutive female patients with outlet delay were submitted to 2D and 3D-DAUS, measuring the relaxing or contracting puborectalis muscle angle during straining. The patients were assigned to one of two groups based on ECD findings. Group I consisted of 29 patients without anismus and group II included 21 patients diagnosed with anismus. Subsequently 2D-DAUS images were checked for anismus and compared with ECD findings. Upon straining, the angle produced by the movement of the puborectalis muscle decreased in 26 out of the 29 (89.6%) patients of group I and increased 19 out of the 21 (90.4%) patients of group II. The mean angle during straining differed significantly between group I and group II. The index of agreement between the two scanning modes was 89.6% (26/29) for group I (Kappa: 0.796; CI: 95%; range: 0.51-1.0) and 90.4% (19/21) for group II (Kappa: 0.796; CI: 95%; range: 0.51-1.0). Two-dimensional dynamic anal ultrasonography can be used as an alternative method to assess patients with anismus, although the 3-D modality is more precise to evaluate the PR angle as the sphincters integrity as the whole muscle length is clearly visualized.

Control of Multiple Exciton Generation and Electron-Phonon Coupling by Interior Nanospace in Hyperstructured Quantum Dot Superlattice.

PubMed

Chang, I-Ya; Kim, DaeGwi; Hyeon-Deuk, Kim

2017-09-20

The possibility of precisely manipulating interior nanospace, which can be adjusted by ligand-attaching down to the subnanometer regime, in a hyperstructured quantum dot (QD) superlattice (QDSL) induces a new kind of collective resonant coupling among QDs and opens up new opportunities for developing advanced optoelectric and photovoltaic devices. Here, we report the first real-time dynamics simulations of the multiple exciton generation (MEG) in one-, two-, and three-dimensional (1D, 2D, and 3D) hyperstructured H-passivated Si QDSLs, accounting for thermally fluctuating band energies and phonon dynamics obtained by finite-temperature ab initio molecular dynamics simulations. We computationally demonstrated that the MEG was significantly accelerated, especially in the 3D QDSL compared to the 1D and 2D QDSLs. The MEG acceleration in the 3D QDSL was almost 1.9 times the isolated QD case. The dimension-dependent MEG acceleration was attributed not only to the static density of states but also to the dynamical electron-phonon couplings depending on the dimensionality of the hyperstructured QDSL, which is effectively controlled by the interior nanospace. Such dimension-dependent modifications originated from the short-range quantum resonance among component QDs and were intrinsic to the hyperstructured QDSL. We propose that photoexcited dynamics including the MEG process can be effectively controlled by only manipulating the interior nanospace of the hyperstructured QDSL without changing component QD size, shape, compositions, ligand, etc.

Three-dimensional dynamical and chemical modelling of the upper atmosphere

NASA Technical Reports Server (NTRS)

Prinn, R. G.; Alyea, F. N.; Cunnold, D. M.

1976-01-01

Progress in coding a 3-D upper atmospheric model and in modeling the ozone perturbation resulting from the shuttle booster exhaust is reported. A time-dependent version of a 2-D model was studied and the sulfur cycle in the stratosphere was investigated. The role of meteorology in influencing stratospheric composition measurements was also studied.

4D BADA-based Trajectory Generator and 3D Guidance Algorithm

NASA Technical Reports Server (NTRS)

Palacios, Eduardo Sepulveda; Johnson, Marcus A.

2013-01-01

This paper presents a hybrid integration between aerodynamic, airline procedures and other BADA-based (Base of Aircraft Data) coefficients with a classical aircraft dynamic model. This paper also describes a three-dimensional guidance algorithm implemented in order to produce commands for the aircraft to follow a flight plan. The software chosen for this work is MATLAB.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ulvestad, A.; Welland, M. J.; Cha, W.

Crystallographic imperfections can significantly alter material properties and responses to external stimuli, including solute induced phase transformations and crystal growth and dissolution . Despite recent progress in imaging defects using both electron and x-ray techniques, in situ three-dimensional imaging studies of defect dynamics, necessary to understand and engineer nanoscale processes, remains challenging. Here, we report in situ three-dimensional imaging of defect dynamics during the hydriding phase transformation of individual palladium nanocrystals by Bragg Coherent Diffractive Imaging (BCDI) . During constant pressure experiments, we observed that the phase transformation begins after the nucleation of dislocations in large (300 nm) particles. Themore » 3D dislocation network shows that dislocations are close to the phase boundary. The 3D phase morphology resolved by BCDI suggests that the hydrogen-rich phase is more similar to a spherical cap on the hydrogen-poor phase than the core-shell model commonly assumed. We substantiate this conclusion using 3D phase field modeling and demonstrate how phase morphology affects the critical size for dislocation nucleation. We determine the size dependence of the transformation pressure for large (150-300 nm) palladium nanocrystals using variable pressure experiments. Our results reveal a pathway for solute induced structural phase transformations in nanocrystals and demonstrate BCDI as a novel method for understanding dislocation dynamics in phase transforming systems at the nanoscale.« less

Dynamical Chern-Simons Theory in the Brillouin Zone

NASA Astrophysics Data System (ADS)

Lian, Biao; Vafa, Cumrun; Vafa, Farzan; Zhang, Shou-Cheng

Berry connection is conventionally defined as a static gauge field in the Brillouin zone. Here we show that for three-dimensional (3d) time-reversal invariant superconductors, a generalized Berry gauge field behaves as a dynamical fluctuating field of a Chern-Simons gauge theory. The gapless nodal lines in the momentum space play the role of Wilson loop observables, while their linking and knot invariants modify the gravitational theta angle. This angle induces a topological gravitomagnetoelectric effect where a temperature gradient induces a rotational energy flow. We also show how topological strings may be realized in the 6 dimensional phase space, where the physical space defects play the role of topological D-branes.

Dynamic Self-Assembly of Gold/Polymer Nanocomposites: pH-Encoded Switching between 1D Nanowires and 3D Nanosponges.

PubMed

Zhang, Qi; Xu, Tian-Yi; Zhao, Cai-Xin; Jin, Wei-Hang; Wang, Qian; Qu, Da-Hui

2017-10-05

The design of tunable dynamic self-assembly of nanoparticles with switchable assembled dimensions and morphologies is a challenging goal whose realization is vital for the evolution of smart nanomaterials. Herein, we report on chitosan polymer as an effective supramolecular "glue" for aldehyde-modified Au nanoparticles to reversibly modulate the states of self-assembled nanocomposites. By simultaneous integration of dynamic covalent Schiff base interactions and noncovalent hydrogen bonds, the chitosan/Au nanocomposites could reversibly transform their assembled morphologies from one-dimensional nanowires to three-dimensional nanosponges in response to the variation of pH value. Moreover, the obtained nanosponges could be used as an efficient pH-controlled cargo release system. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Three-dimensional audio-magnetotelluric sounding in monitoring coalbed methane reservoirs

NASA Astrophysics Data System (ADS)

Wang, Nan; Zhao, Shanshan; Hui, Jian; Qin, Qiming

2017-03-01

Audio-magnetotelluric (AMT) sounding is widely employed in rapid resistivity delineation of objective geometry in near surface exploration. According to reservoir patterns and electrical parameters obtained in Qinshui Basin, China, two-dimensional and three-dimensional synthetic "objective anomaly" models were designed and inverted with the availability of a modular system for electromagnetic inversion (ModEM). The results revealed that 3-D full impedance inversion yielded the subsurface models closest to synthetic models. One or more conductive targets were correctly recovered. Therefore, conductive aquifers in the study area, including hydrous coalbed methane (CBM) reservoirs, were suggested to be the interpretation signs for reservoir characterization. With the aim of dynamic monitoring of CBM reservoirs, the AMT surveys in continuous years (June 2013-May 2015) were carried out. 3-D inversion results demonstrated that conductive anomalies accumulated around the producing reservoirs at the corresponding depths if CBM reservoirs were in high water production rates. In contrast, smaller conductive anomalies were generally identical with rapid gas production or stopping production of reservoirs. These analyses were in accordance with actual production history of CBM wells. The dynamic traces of conductive anomalies revealed that reservoir water migrated deep or converged in axial parts and wings of folds, which contributed significantly to formations of CBM traps. Then the well spacing scenario was also evaluated based on the dynamic production analysis. Wells distributed near closed faults or flat folds, rather than open faults, had CBM production potential to ascertain stable gas production. Therefore, three-dimensional AMT sounding becomes an attractive option with the ability of dynamic monitoring of CBM reservoirs, and lays a solid foundation of quantitative evaluation of reservoir parameters.

3D Medical Collaboration Technology to Enhance Emergency Healthcare

PubMed Central

Welch, Greg; Sonnenwald, Diane H; Fuchs, Henry; Cairns, Bruce; Mayer-Patel, Ketan; Söderholm, Hanna M.; Yang, Ruigang; State, Andrei; Towles, Herman; Ilie, Adrian; Ampalam, Manoj; Krishnan, Srinivas; Noel, Vincent; Noland, Michael; Manning, James E.

2009-01-01

Two-dimensional (2D) videoconferencing has been explored widely in the past 15–20 years to support collaboration in healthcare. Two issues that arise in most evaluations of 2D videoconferencing in telemedicine are the difficulty obtaining optimal camera views and poor depth perception. To address these problems, we are exploring the use of a small array of cameras to reconstruct dynamic three-dimensional (3D) views of a remote environment and of events taking place within. The 3D views could be sent across wired or wireless networks to remote healthcare professionals equipped with fixed displays or with mobile devices such as personal digital assistants (PDAs). The remote professionals’ viewpoints could be specified manually or automatically (continuously) via user head or PDA tracking, giving the remote viewers head-slaved or hand-slaved virtual cameras for monoscopic or stereoscopic viewing of the dynamic reconstructions. We call this idea remote 3D medical collaboration. In this article we motivate and explain the vision for 3D medical collaboration technology; we describe the relevant computer vision, computer graphics, display, and networking research; we present a proof-of-concept prototype system; and we present evaluation results supporting the general hypothesis that 3D remote medical collaboration technology could offer benefits over conventional 2D videoconferencing in emergency healthcare. PMID:19521951

3D medical collaboration technology to enhance emergency healthcare.

PubMed

Welch, Gregory F; Sonnenwald, Diane H; Fuchs, Henry; Cairns, Bruce; Mayer-Patel, Ketan; Söderholm, Hanna M; Yang, Ruigang; State, Andrei; Towles, Herman; Ilie, Adrian; Ampalam, Manoj K; Krishnan, Srinivas; Noel, Vincent; Noland, Michael; Manning, James E

2009-04-19

Two-dimensional (2D) videoconferencing has been explored widely in the past 15-20 years to support collaboration in healthcare. Two issues that arise in most evaluations of 2D videoconferencing in telemedicine are the difficulty obtaining optimal camera views and poor depth perception. To address these problems, we are exploring the use of a small array of cameras to reconstruct dynamic three-dimensional (3D) views of a remote environment and of events taking place within. The 3D views could be sent across wired or wireless networks to remote healthcare professionals equipped with fixed displays or with mobile devices such as personal digital assistants (PDAs). The remote professionals' viewpoints could be specified manually or automatically (continuously) via user head or PDA tracking, giving the remote viewers head-slaved or hand-slaved virtual cameras for monoscopic or stereoscopic viewing of the dynamic reconstructions. We call this idea remote 3D medical collaboration. In this article we motivate and explain the vision for 3D medical collaboration technology; we describe the relevant computer vision, computer graphics, display, and networking research; we present a proof-of-concept prototype system; and we present evaluation results supporting the general hypothesis that 3D remote medical collaboration technology could offer benefits over conventional 2D videoconferencing in emergency healthcare.

Three-dimensional particle tracking velocimetry using dynamic vision sensors

NASA Astrophysics Data System (ADS)

Borer, D.; Delbruck, T.; Rösgen, T.

2017-12-01

A fast-flow visualization method is presented based on tracking neutrally buoyant soap bubbles with a set of neuromorphic cameras. The "dynamic vision sensors" register only the changes in brightness with very low latency, capturing fast processes at a low data rate. The data consist of a stream of asynchronous events, each encoding the corresponding pixel position, the time instant of the event and the sign of the change in logarithmic intensity. The work uses three such synchronized cameras to perform 3D particle tracking in a medium sized wind tunnel. The data analysis relies on Kalman filters to associate the asynchronous events with individual tracers and to reconstruct the three-dimensional path and velocity based on calibrated sensor information.

Systematic literature review of digital three-dimensional superimposition techniques to create virtual dental patients.

PubMed

Joda, Tim; Brägger, Urs; Gallucci, German

2015-01-01

Digital developments have led to the opportunity to compose simulated patient models based on three-dimensional (3D) skeletal, facial, and dental imaging. The aim of this systematic review is to provide an update on the current knowledge, to report on the technical progress in the field of 3D virtual patient science, and to identify further research needs to accomplish clinical translation. Searches were performed electronically (MEDLINE and OVID) and manually up to March 2014 for studies of 3D fusion imaging to create a virtual dental patient. Inclusion criteria were limited to human studies reporting on the technical protocol for superimposition of at least two different 3D data sets and medical field of interest. Of the 403 titles originally retrieved, 51 abstracts and, subsequently, 21 full texts were selected for review. Of the 21 full texts, 18 studies were included in the systematic review. Most of the investigations were designed as feasibility studies. Three different types of 3D data were identified for simulation: facial skeleton, extraoral soft tissue, and dentition. A total of 112 patients were investigated in the development of 3D virtual models. Superimposition of data on the facial skeleton, soft tissue, and/or dentition is a feasible technique to create a virtual patient under static conditions. Three-dimensional image fusion is of interest and importance in all fields of dental medicine. Future research should focus on the real-time replication of a human head, including dynamic movements, capturing data in a single step.

S2PLOT: Three-dimensional (3D) Plotting Library

NASA Astrophysics Data System (ADS)

Barnes, D. G.; Fluke, C. J.; Bourke, P. D.; Parry, O. T.

2011-03-01

We present a new, three-dimensional (3D) plotting library with advanced features, and support for standard and enhanced display devices. The library - S2PLOT - is written in C and can be used by C, C++ and FORTRAN programs on GNU/Linux and Apple/OSX systems. S2PLOT draws objects in a 3D (x,y,z) Cartesian space and the user interactively controls how this space is rendered at run time. With a PGPLOT inspired interface, S2PLOT provides astronomers with elegant techniques for displaying and exploring 3D data sets directly from their program code, and the potential to use stereoscopic and dome display devices. The S2PLOT architecture supports dynamic geometry and can be used to plot time-evolving data sets, such as might be produced by simulation codes. In this paper, we introduce S2PLOT to the astronomical community, describe its potential applications, and present some example uses of the library.

Three-dimensional carbon allotropes comprising phenyl rings and acetylenic chains in sp+ sp 2 hybrid networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jian -Tao; Chen, Changfeng; Li, Han -Dong

Here, we here identify by ab initio calculations a new type of three-dimensional (3D) carbon allotropes that consist of phenyl rings connected by linear acetylenic chains in sp+ sp 2 bonding networks. These structures are constructed by inserting acetylenic or diacetylenic bonds into an all sp 2-hybridized rhombohedral polybenzene lattice, and the resulting 3D phenylacetylene and phenyldiacetylene nets comprise a 12-atom and 18-atom rhombohedral primitive unit cells R - 3m symmetry, which are characterized as the 3D chiral crystalline modification of 2D graphyne and graphdiyne, respectively. Simulated phonon spectra reveal that these structures are dynamically stable. Electronic band calculations indicatemore » that phenylacetylene is metallic, while phenyldiacetylene is a semiconductor with an indirect band gap of 0.58 eV. The present results establish a new type of carbon phases and offer insights into their outstanding structural and electronic properties.« less

Three-dimensional carbon allotropes comprising phenyl rings and acetylenic chains in sp+ sp 2 hybrid networks

DOE PAGES

Wang, Jian -Tao; Chen, Changfeng; Li, Han -Dong; ...

2016-04-18

Here, we here identify by ab initio calculations a new type of three-dimensional (3D) carbon allotropes that consist of phenyl rings connected by linear acetylenic chains in sp+ sp 2 bonding networks. These structures are constructed by inserting acetylenic or diacetylenic bonds into an all sp 2-hybridized rhombohedral polybenzene lattice, and the resulting 3D phenylacetylene and phenyldiacetylene nets comprise a 12-atom and 18-atom rhombohedral primitive unit cells R - 3m symmetry, which are characterized as the 3D chiral crystalline modification of 2D graphyne and graphdiyne, respectively. Simulated phonon spectra reveal that these structures are dynamically stable. Electronic band calculations indicatemore » that phenylacetylene is metallic, while phenyldiacetylene is a semiconductor with an indirect band gap of 0.58 eV. The present results establish a new type of carbon phases and offer insights into their outstanding structural and electronic properties.« less

Integration of fringe projection and two-dimensional digital image correlation for three-dimensional displacements measurements

NASA Astrophysics Data System (ADS)

Felipe-Sesé, Luis; López-Alba, Elías; Siegmann, Philip; Díaz, Francisco A.

2016-12-01

A low-cost approach for three-dimensional (3-D) full-field displacement measurement is applied for the analysis of large displacements involved in two different mechanical events. The method is based on a combination of fringe projection and two-dimensional digital image correlation (DIC) techniques. The two techniques have been employed simultaneously using an RGB camera and a color encoding method; therefore, it is possible to measure in-plane and out-of-plane displacements at the same time with only one camera even at high speed rates. The potential of the proposed methodology has been employed for the analysis of large displacements during contact experiments in a soft material block. Displacement results have been successfully compared with those obtained using a 3D-DIC commercial system. Moreover, the analysis of displacements during an impact test on a metal plate was performed to emphasize the application of the methodology for dynamics events. Results show a good level of agreement, highlighting the potential of FP + 2D DIC as low-cost alternative for the analysis of large deformations problems.

4D bioprinting: the next-generation technology for biofabrication enabled by stimuli-responsive materials.

PubMed

Li, Yi-Chen; Zhang, Yu Shrike; Akpek, Ali; Shin, Su Ryon; Khademhosseini, Ali

2016-12-02

Four-dimensional (4D) bioprinting, encompassing a wide range of disciplines including bioengineering, materials science, chemistry, and computer sciences, is emerging as the next-generation biofabrication technology. By utilizing stimuli-responsive materials and advanced three-dimensional (3D) bioprinting strategies, 4D bioprinting aims to create dynamic 3D patterned biological structures that can transform their shapes or behavior under various stimuli. In this review, we highlight the potential use of various stimuli-responsive materials for 4D printing and their extension into biofabrication. We first discuss the state of the art and limitations associated with current 3D printing modalities and their transition into the inclusion of the additional time dimension. We then suggest the potential use of different stimuli-responsive biomaterials as the bioink that may achieve 4D bioprinting where transformation of fabricated biological constructs can be realized. We finally conclude with future perspectives.

Surprising loss of three-dimensionality in low-energy spin correlations on approaching superconductivity in Fe 1 + y Te 1 - x Se x

DOE PAGES

Xu, Zhijun; Schneeloch, J. A.; Wen, Jinsheng; ...

2017-10-06

We report inelastic neutron scattering measurements of low-energy ( ℏ ω ≲ 10 meV) magnetic excitations in the “11” system Fe 1+y Te 1-x Se x. The spin correlations are two-dimensional (2D) in the superconducting samples at low temperature, but appear much more three-dimensional (3D) when the temperature rises well above T c ~ 15 K, with a clear increase of the (dynamic) spin correlation length perpendicular to the Fe planes. This behavior is extremely unusual; typically, the suppression of thermal fluctuations at low temperature would favor the enhancement of 3D correlations, or even ordering, and the reversion to 2Dmore » cannot be naturally explained when only the spin degree of freedom is considered. Our results suggest that the low temperature physics in the 11 system, in particular the evolution of low-energy spin excitations towards superconducting pairing, intrinsically involves changes in orbital correlations.« less

Surprising loss of three-dimensionality in low-energy spin correlations on approaching superconductivity in Fe 1 + y Te 1 - x Se x

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Zhijun; Schneeloch, J. A.; Wen, Jinsheng

We report inelastic neutron scattering measurements of low-energy ( ℏ ω ≲ 10 meV) magnetic excitations in the “11” system Fe 1+y Te 1-x Se x. The spin correlations are two-dimensional (2D) in the superconducting samples at low temperature, but appear much more three-dimensional (3D) when the temperature rises well above T c ~ 15 K, with a clear increase of the (dynamic) spin correlation length perpendicular to the Fe planes. This behavior is extremely unusual; typically, the suppression of thermal fluctuations at low temperature would favor the enhancement of 3D correlations, or even ordering, and the reversion to 2Dmore » cannot be naturally explained when only the spin degree of freedom is considered. Our results suggest that the low temperature physics in the 11 system, in particular the evolution of low-energy spin excitations towards superconducting pairing, intrinsically involves changes in orbital correlations.« less

Detection of one-dimensional migration of single self-interstitial atoms in tungsten using high-voltage electron microscopy

PubMed Central

Amino, T.; Arakawa, K.; Mori, H.

2016-01-01

The dynamic behaviour of atomic-size disarrangements of atoms—point defects (self-interstitial atoms (SIAs) and vacancies)—often governs the macroscopic properties of crystalline materials. However, the dynamics of SIAs have not been fully uncovered because of their rapid migration. Using a combination of high-voltage transmission electron microscopy and exhaustive kinetic Monte Carlo simulations, we determine the dynamics of the rapidly migrating SIAs from the formation process of the nanoscale SIA clusters in tungsten as a typical body-centred cubic (BCC) structure metal under the constant-rate production of both types of point defects with high-energy electron irradiation, which must reflect the dynamics of individual SIAs. We reveal that the migration dimension of SIAs is not three-dimensional (3D) but one-dimensional (1D). This result overturns the long-standing and well-accepted view of SIAs in BCC metals and supports recent results obtained by ab-initio simulations. The SIA dynamics clarified here will be one of the key factors to accurately predict the lifetimes of nuclear fission and fusion materials. PMID:27185352

High-frame-rate full-vocal-tract 3D dynamic speech imaging.

PubMed

Fu, Maojing; Barlaz, Marissa S; Holtrop, Joseph L; Perry, Jamie L; Kuehn, David P; Shosted, Ryan K; Liang, Zhi-Pei; Sutton, Bradley P

2017-04-01

To achieve high temporal frame rate, high spatial resolution and full-vocal-tract coverage for three-dimensional dynamic speech MRI by using low-rank modeling and sparse sampling. Three-dimensional dynamic speech MRI is enabled by integrating a novel data acquisition strategy and an image reconstruction method with the partial separability model: (a) a self-navigated sparse sampling strategy that accelerates data acquisition by collecting high-nominal-frame-rate cone navigator sand imaging data within a single repetition time, and (b) are construction method that recovers high-quality speech dynamics from sparse (k,t)-space data by enforcing joint low-rank and spatiotemporal total variation constraints. The proposed method has been evaluated through in vivo experiments. A nominal temporal frame rate of 166 frames per second (defined based on a repetition time of 5.99 ms) was achieved for an imaging volume covering the entire vocal tract with a spatial resolution of 2.2 × 2.2 × 5.0 mm 3 . Practical utility of the proposed method was demonstrated via both validation experiments and a phonetics investigation. Three-dimensional dynamic speech imaging is possible with full-vocal-tract coverage, high spatial resolution and high nominal frame rate to provide dynamic speech data useful for phonetic studies. Magn Reson Med 77:1619-1629, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Adiabatic Invariant Approach to Transverse Instability: Landau Dynamics of Soliton Filaments.

PubMed

Kevrekidis, P G; Wang, Wenlong; Carretero-González, R; Frantzeskakis, D J

2017-06-16

Consider a lower-dimensional solitonic structure embedded in a higher-dimensional space, e.g., a 1D dark soliton embedded in 2D space, a ring dark soliton in 2D space, a spherical shell soliton in 3D space, etc. By extending the Landau dynamics approach [Phys. Rev. Lett. 93, 240403 (2004)PRLTAO0031-900710.1103/PhysRevLett.93.240403], we show that it is possible to capture the transverse dynamical modes (the "Kelvin modes") of the undulation of this "soliton filament" within the higher-dimensional space. These are the transverse stability or instability modes and are the ones potentially responsible for the breakup of the soliton into structures such as vortices, vortex rings, etc. We present the theory and case examples in 2D and 3D, corroborating the results by numerical stability and dynamical computations.

3D Flow visualization in virtual reality

NASA Astrophysics Data System (ADS)

Pietraszewski, Noah; Dhillon, Ranbir; Green, Melissa

2017-11-01

By viewing fluid dynamic isosurfaces in virtual reality (VR), many of the issues associated with the rendering of three-dimensional objects on a two-dimensional screen can be addressed. In addition, viewing a variety of unsteady 3D data sets in VR opens up novel opportunities for education and community outreach. In this work, the vortex wake of a bio-inspired pitching panel was visualized using a three-dimensional structural model of Q-criterion isosurfaces rendered in virtual reality using the HTC Vive. Utilizing the Unity cross-platform gaming engine, a program was developed to allow the user to control and change this model's position and orientation in three-dimensional space. In addition to controlling the model's position and orientation, the user can ``scroll'' forward and backward in time to analyze the formation and shedding of vortices in the wake. Finally, the user can toggle between different quantities, while keeping the time step constant, to analyze flow parameter relationships at specific times during flow development. The information, data, or work presented herein was funded in part by an award from NYS Department of Economic Development (DED) through the Syracuse Center of Excellence.

Exciton recombination dynamics in CdSe nanowires: bimolecular to three-carrier Auger kinetics.

PubMed

Robel, István; Bunker, Bruce A; Kamat, Prashant V; Kuno, Masaru

2006-07-01

Ultrafast relaxation dynamics of charge carriers in CdSe quantum wires with diameters between 6 and 8 nm are studied as a function of carrier density. At high electron-hole pair densities above 10(19) cm(-3) the dominant process for carrier cooling is the "bimolecular" Auger recombination of one-dimensional (1D) excitons. However, below this excitation level an unexpected transition from a bimolecular (exciton-exciton) to a three-carrier Auger relaxation mechanism occurs. Thus, depending on excitation intensity, electron-hole pair relaxation dynamics in the nanowires exhibit either 1D or 0D (quantum dot) character. This dual nature of the recovery kinetics defines an optimal intensity for achieving optical gain in solution-grown nanowires given the different carrier-density-dependent scaling of relaxation rates in either regime.

A three dimensional immersed smoothed finite element method (3D IS-FEM) for fluid-structure interaction problems

NASA Astrophysics Data System (ADS)

Zhang, Zhi-Qian; Liu, G. R.; Khoo, Boo Cheong

2013-02-01

A three-dimensional immersed smoothed finite element method (3D IS-FEM) using four-node tetrahedral element is proposed to solve 3D fluid-structure interaction (FSI) problems. The 3D IS-FEM is able to determine accurately the physical deformation of the nonlinear solids placed within the incompressible viscous fluid governed by Navier-Stokes equations. The method employs the semi-implicit characteristic-based split scheme to solve the fluid flows and smoothed finite element methods to calculate the transient dynamics responses of the nonlinear solids based on explicit time integration. To impose the FSI conditions, a novel, effective and sufficiently general technique via simple linear interpolation is presented based on Lagrangian fictitious fluid meshes coinciding with the moving and deforming solid meshes. In the comparisons to the referenced works including experiments, it is clear that the proposed 3D IS-FEM ensures stability of the scheme with the second order spatial convergence property; and the IS-FEM is fairly independent of a wide range of mesh size ratio.

4-D photoacoustic tomography.

PubMed

Xiang, Liangzhong; Wang, Bo; Ji, Lijun; Jiang, Huabei

2013-01-01

Photoacoustic tomography (PAT) offers three-dimensional (3D) structural and functional imaging of living biological tissue with label-free, optical absorption contrast. These attributes lend PAT imaging to a wide variety of applications in clinical medicine and preclinical research. Despite advances in live animal imaging with PAT, there is still a need for 3D imaging at centimeter depths in real-time. We report the development of four dimensional (4D) PAT, which integrates time resolutions with 3D spatial resolution, obtained using spherical arrays of ultrasonic detectors. The 4D PAT technique generates motion pictures of imaged tissue, enabling real time tracking of dynamic physiological and pathological processes at hundred micrometer-millisecond resolutions. The 4D PAT technique is used here to image needle-based drug delivery and pharmacokinetics. We also use this technique to monitor 1) fast hemodynamic changes during inter-ictal epileptic seizures and 2) temperature variations during tumor thermal therapy.

Imaging galectin-3 dependent endocytosis with lattice light-sheet microscopy

NASA Astrophysics Data System (ADS)

Baek, Jongho; Lou, Jieqiong; Coelho, Simao; Lim, Yean Jin; Seidlitz, Silvia; Nicovich, Philip R.; Wunder, Christian; Johannes, Ludger; Gaus, Katharina

2017-04-01

Lattice light-sheet (LLS) microscopy provides ultrathin light sheets of a two-dimensional optical lattice that allows us imaging three-dimensional (3D) objects for hundreds of time points at sub-second intervals and at or below the diffraction limit. Galectin-3 (Gal3), a carbohydrate-binding protein, triggers glycosphingolipid (GSL)-dependent biogenesis of morphologically distinct endocytic vesicles that are cargo specific and clathrin independent. In this study, we apply LLS microscopy to study the dynamics of Gal3 dependent endocytosis in live T cells. This will allow us to observe Gal3-mediated endocytosis at high temporal and excellent 3D spatial resolution, which may shed light on our understanding of the mechanism and physiological function of Gal3-induced endocytosis.

Complexity dynamics and Hopf bifurcation analysis based on the first Lyapunov coefficient about 3D IS-LM macroeconomics system

NASA Astrophysics Data System (ADS)

Ma, Junhai; Ren, Wenbo; Zhan, Xueli

2017-04-01

Based on the study of scholars at home and abroad, this paper improves the three-dimensional IS-LM model in macroeconomics, analyzes the equilibrium point of the system and stability conditions, focuses on the parameters and complex dynamic characteristics when Hopf bifurcation occurs in the three-dimensional IS-LM macroeconomics system. In order to analyze the stability of limit cycles when Hopf bifurcation occurs, this paper further introduces the first Lyapunov coefficient to judge the limit cycles, i.e. from a practical view of the business cycle. Numerical simulation results show that within the range of most of the parameters, the limit cycle of 3D IS-LM macroeconomics is stable, that is, the business cycle is stable; with the increase of the parameters, limit cycles becomes unstable, and the value range of the parameters in this situation is small. The research results of this paper have good guide significance for the analysis of macroeconomics system.

THE ROLE OF A FLUX ROPE EJECTION IN A THREE-DIMENSIONAL MAGNETOHYDRODYNAMIC SIMULATION OF A SOLAR FLARE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishida, Keisuke; Shibata, Kazunari; Nishizuka, Naoto, E-mail: nishida@kwasan.kyoto-u.ac.jp

2013-10-01

We investigated the dynamic evolution of a three-dimensional (3D) flux rope eruption and magnetic reconnection process in a solar flare by simply extending the two-dimensional (2D) resistive magnetohydrodynamic simulation model of solar flares with low β plasma to a 3D model. We succeeded in reproducing a current sheet and bi-directional reconnection outflows just below the flux rope during the eruption in our 3D simulations. We calculated four cases of a strongly twisted flux rope and a weakly twisted flux rope in 2D and 3D simulations. The time evolution of a weakly twisted flux rope in the 3D simulation shows behaviorsmore » similar to those of the 2D simulation, while a strongly twisted flux rope in the 3D simulation clearly shows a different time evolution from the 2D simulation except for the initial phase evolution. The ejection speeds of both strongly and weakly twisted flux ropes in 3D simulations are larger than in the 2D simulations, and the reconnection rates in 3D cases are also larger than in the 2D cases. This indicates positive feedback between the ejection speed of a flux rope and the reconnection rate even in the 3D simulation, and we conclude that the plasmoid-induced reconnection model can be applied to 3D. We also found that small-scale plasmoids are formed inside a current sheet and make it turbulent. These small-scale plasmoid ejections have a role in locally increasing the reconnection rate intermittently as observed in solar flares, coupled with a global eruption of a flux rope.« less

Hepatic Differentiation of Human Induced Pluripotent Stem Cells in a Perfused Three-Dimensional Multicompartment Bioreactor.

PubMed

Freyer, Nora; Knöspel, Fanny; Strahl, Nadja; Amini, Leila; Schrade, Petra; Bachmann, Sebastian; Damm, Georg; Seehofer, Daniel; Jacobs, Frank; Monshouwer, Mario; Zeilinger, Katrin

2016-01-01

The hepatic differentiation of human induced pluripotent stem cells (hiPSC) holds great potential for application in regenerative medicine, pharmacological drug screening, and toxicity testing. However, full maturation of hiPSC into functional hepatocytes has not yet been achieved. In this study, we investigated the potential of a dynamic three-dimensional (3D) hollow fiber membrane bioreactor technology to improve the hepatic differentiation of hiPSC in comparison to static two-dimensional (2D) cultures. A total of 100 × 10(6) hiPSC were seeded into each 3D bioreactor (n = 3). Differentiation into definitive endoderm (DE) was induced by adding activin A, Wnt3a, and sodium butyrate to the culture medium. For further maturation, hepatocyte growth factor and oncostatin M were added. The same differentiation protocol was applied to hiPSC maintained in 2D cultures. Secretion of alpha-fetoprotein (AFP), a marker for DE, was significantly (p < 0.05) higher in 2D cultures, while secretion of albumin, a typical characteristic for mature hepatocytes, was higher after hepatic differentiation of hiPSC in 3D bioreactors. Functional analysis of multiple cytochrome P450 (CYP) isoenzymes showed activity of CYP1A2, CYP2B6, and CYP3A4 in both groups, although at a lower level compared to primary human hepatocytes (PHH). CYP2B6 activities were significantly (p < 0.05) higher in 3D bioreactors compared with 2D cultures, which is in line with results from gene expression. Immunofluorescence staining showed that the majority of cells was positive for albumin, cytokeratin 18 (CK18), and hepatocyte nuclear factor 4-alpha (HNF4A) at the end of the differentiation process. In addition, cytokeratin 19 (CK19) staining revealed the formation of bile duct-like structures in 3D bioreactors similar to native liver tissue. The results indicate a better maturation of hiPSC in the 3D bioreactor system compared to 2D cultures and emphasize the potential of dynamic 3D culture systems in stem cell differentiation approaches for improved formation of differentiated tissue structures.

Hepatic Differentiation of Human Induced Pluripotent Stem Cells in a Perfused Three-Dimensional Multicompartment Bioreactor

PubMed Central

Freyer, Nora; Knöspel, Fanny; Strahl, Nadja; Amini, Leila; Schrade, Petra; Bachmann, Sebastian; Damm, Georg; Seehofer, Daniel; Jacobs, Frank; Monshouwer, Mario; Zeilinger, Katrin

2016-01-01

Abstract The hepatic differentiation of human induced pluripotent stem cells (hiPSC) holds great potential for application in regenerative medicine, pharmacological drug screening, and toxicity testing. However, full maturation of hiPSC into functional hepatocytes has not yet been achieved. In this study, we investigated the potential of a dynamic three-dimensional (3D) hollow fiber membrane bioreactor technology to improve the hepatic differentiation of hiPSC in comparison to static two-dimensional (2D) cultures. A total of 100 × 106 hiPSC were seeded into each 3D bioreactor (n = 3). Differentiation into definitive endoderm (DE) was induced by adding activin A, Wnt3a, and sodium butyrate to the culture medium. For further maturation, hepatocyte growth factor and oncostatin M were added. The same differentiation protocol was applied to hiPSC maintained in 2D cultures. Secretion of alpha-fetoprotein (AFP), a marker for DE, was significantly (p < 0.05) higher in 2D cultures, while secretion of albumin, a typical characteristic for mature hepatocytes, was higher after hepatic differentiation of hiPSC in 3D bioreactors. Functional analysis of multiple cytochrome P450 (CYP) isoenzymes showed activity of CYP1A2, CYP2B6, and CYP3A4 in both groups, although at a lower level compared to primary human hepatocytes (PHH). CYP2B6 activities were significantly (p < 0.05) higher in 3D bioreactors compared with 2D cultures, which is in line with results from gene expression. Immunofluorescence staining showed that the majority of cells was positive for albumin, cytokeratin 18 (CK18), and hepatocyte nuclear factor 4-alpha (HNF4A) at the end of the differentiation process. In addition, cytokeratin 19 (CK19) staining revealed the formation of bile duct-like structures in 3D bioreactors similar to native liver tissue. The results indicate a better maturation of hiPSC in the 3D bioreactor system compared to 2D cultures and emphasize the potential of dynamic 3D culture systems in stem cell differentiation approaches for improved formation of differentiated tissue structures. PMID:27610270

The Progenitor Dependence of Core-collapse Supernovae from Three-dimensional Simulations with Progenitor Models of 12–40 M ⊙

NASA Astrophysics Data System (ADS)

Ott, Christian D.; Roberts, Luke F.; da Silva Schneider, André; Fedrow, Joseph M.; Haas, Roland; Schnetter, Erik

2018-03-01

We present a first study of the progenitor star dependence of the three-dimensional (3D) neutrino mechanism of core-collapse supernovae. We employ full 3D general-relativistic multi-group neutrino radiation-hydrodynamics and simulate the postbounce evolutions of progenitors with zero-age main sequence masses of 12, 15, 20, 27, and 40 M ⊙. All progenitors, with the exception of the 12 M ⊙ star, experience shock runaway by the end of their simulations. In most cases, a strongly asymmetric explosion will result. We find three qualitatively distinct evolutions that suggest a complex dependence of explosion dynamics on progenitor density structure, neutrino heating, and 3D flow. (1) Progenitors with massive cores, shallow density profiles, and high post-core-bounce accretion rates experience very strong neutrino heating and neutrino-driven turbulent convection, leading to early shock runaway. Accretion continues at a high rate, likely leading to black hole formation. (2) Intermediate progenitors experience neutrino-driven, turbulence-aided explosions triggered by the arrival of density discontinuities at the shock. These occur typically at the silicon/silicon–oxygen shell boundary. (3) Progenitors with small cores and density profiles without strong discontinuities experience shock recession and develop the 3D standing-accretion shock instability (SASI). Shock runaway ensues late, once declining accretion rate, SASI, and neutrino-driven convection create favorable conditions. These differences in explosion times and dynamics result in a non-monotonic relationship between progenitor and compact remnant mass.

Left ventricular volume estimation in cardiac three-dimensional ultrasound: a semiautomatic border detection approach.

PubMed

van Stralen, Marijn; Bosch, Johan G; Voormolen, Marco M; van Burken, Gerard; Krenning, Boudewijn J; van Geuns, Robert-Jan M; Lancée, Charles T; de Jong, Nico; Reiber, Johan H C

2005-10-01

We propose a semiautomatic endocardial border detection method for three-dimensional (3D) time series of cardiac ultrasound (US) data based on pattern matching and dynamic programming, operating on two-dimensional (2D) slices of the 3D plus time data, for the estimation of full cycle left ventricular volume, with minimal user interaction. The presented method is generally applicable to 3D US data and evaluated on data acquired with the Fast Rotating Ultrasound (FRU-) Transducer, developed by Erasmus Medical Center (Rotterdam, the Netherlands), a conventional phased-array transducer, rotating at very high speed around its image axis. The detection is based on endocardial edge pattern matching using dynamic programming, which is constrained by a 3D plus time shape model. It is applied to an automatically selected subset of 2D images of the original data set, for typically 10 equidistant rotation angles and 16 cardiac phases (160 images). Initialization requires the drawing of four contours per patient manually. We evaluated this method on 14 patients against MRI end-diastole and end-systole volumes. Initialization requires the drawing of four contours per patient manually. We evaluated this method on 14 patients against MRI end-diastolic (ED) and end-systolic (ES) volumes. The semiautomatic border detection approach shows good correlations with MRI ED/ES volumes (r = 0.938) and low interobserver variability (y = 1.005x - 16.7, r = 0.943) over full-cycle volume estimations. It shows a high consistency in tracking the user-defined initial borders over space and time. We show that the ease of the acquisition using the FRU-transducer and the semiautomatic endocardial border detection method together can provide a way to quickly estimate the left ventricular volume over the full cardiac cycle using little user interaction.

Recent advances in photorefractive polymers

NASA Astrophysics Data System (ADS)

Thomas, Jayan; Christenson, C. W.; Lynn, B.; Blanche, P.-A.; Voorakaranam, R.; Norwood, R. A.; Yamamoto, M.; Peyghambarian, N.

2011-10-01

Photorefractive composites derived from conducting polymers offer the advantage of dynamically recording holograms without the need for processing of any kind. Thus, they are the material of choice for many cutting edge applications, such as updatable three-dimensional (3D) displays and 3D telepresence. Using photorefractive polymers, 3D images or holograms can be seen with the unassisted eye and are very similar to how humans see the actual environment surrounding them. Absence of a large-area and dynamically updatable holographic recording medium has prevented realization of the concept. The development of a novel nonlinear optical chromophore doped photoconductive polymer composite as the recording medium for a refreshable holographic display is discussed. Further improvements in the polymer composites could bring applications in telemedicine, advertising, updatable 3D maps and entertainment.

Bringing macromolecular machinery to life using 3D animation.

PubMed

Iwasa, Janet H

2015-04-01

Over the past decade, there has been a rapid rise in the use of three-dimensional (3D) animation to depict molecular and cellular processes. Much of the growth in molecular animation has been in the educational arena, but increasingly, 3D animation software is finding its way into research laboratories. In this review, I will discuss a number of ways in which 3d animation software can play a valuable role in visualizing and communicating macromolecular structures and dynamics. I will also consider the challenges of using animation tools within the research sphere. Copyright © 2015. Published by Elsevier Ltd.

A two dimensional interface element for coupling of independently modeled three dimensional finite element meshes and extensions to dynamic and non-linear regimes

NASA Technical Reports Server (NTRS)

Aminpour, Mohammad

1995-01-01

The work reported here pertains only to the first year of research for a three year proposal period. As a prelude to this two dimensional interface element, the one dimensional element was tested and errors were discovered in the code for built-up structures and curved interfaces. These errors were corrected and the benchmark Boeing composite crown panel was analyzed successfully. A study of various splines led to the conclusion that cubic B-splines best suit this interface element application. A least squares approach combined with cubic B-splines was constructed to make a smooth function from the noisy data obtained with random error in the coordinate data points of the Boeing crown panel analysis. Preliminary investigations for the formulation of discontinuous 2-D shell and 3-D solid elements were conducted.

Three-Dimensional Thermal Boundary Layer Corrections for Circular Heat Flux Gauges Mounted in a Flat Plate with a Surface Temperature Discontinuity

NASA Technical Reports Server (NTRS)

Kandula, M.; Haddad, G. F.; Chen, R.-H.

2006-01-01

Three-dimensional Navier-Stokes computational fluid dynamics (CFD) analysis has been performed in an effort to determine thermal boundary layer correction factors for circular convective heat flux gauges (such as Schmidt-Boelter and plug type)mounted flush in a flat plate subjected to a stepwise surface temperature discontinuity. Turbulent flow solutions with temperature-dependent properties are obtained for a free stream Reynolds number of 1E6, and freestream Mach numbers of 2 and 4. The effect of gauge diameter and the plate surface temperature have been investigated. The 3-D CFD results for the heat flux correction factors are compared to quasi-21) results deduced from constant property integral solutions and also 2-D CFD analysis with both constant and variable properties. The role of three-dimensionality and of property variations on the heat flux correction factors has been demonstrated.

Dynamic 3D culture promotes spontaneous embryonic stem cell differentiation in vitro.

PubMed

Gerlach, Jörg C; Hout, Mariah; Edsbagge, Josefina; Björquist, Petter; Lübberstedt, Marc; Miki, Toshio; Stachelscheid, Harald; Schmelzer, Eva; Schatten, Gerald; Zeilinger, Katrin

2010-02-01

Spontaneous in vitro differentiation of mouse embryonic stem cells (mESC) is promoted by a dynamic, three-dimensional (3D), tissue-density perfusion technique with continuous medium perfusion and exchange in a novel four-compartment, interwoven capillary bioreactor. We compared ectodermal, endodermal, and mesodermal immunoreactive tissue structures formed by mESC at culture day 10 with mouse fetal tissue development at gestational day E9.5. The results show that the bioreactor cultures more closely resemble mouse fetal tissue development at gestational day E9.5 than control mESC cultured in Petri dishes.

Self-Assembly of Coherently Dynamic, Auxetic Two-Dimensional Protein Crystals

PubMed Central

Suzuki, Yuta; Cardone, Giovanni; Restrepo, David; Zavattieri, Pablo D.; Baker, Timothy S.; Tezcan, F. Akif

2016-01-01

Two-dimensional (2D) crystalline materials possess unique structural, mechanical, and electronic properties1,2, which have rendered them highly attractive in many applications3-5. Although there have been advances in preparing 2D materials that consist of one or few atomic/molecular layers6,7, bottom-up assembly of 2D crystalline materials remains a considerable challenge and an active area of development8-10. Even more challenging is the design of dynamic 2D lattices that can undergo large-scale motions without loss of crystallinity. Dynamicity in porous 3D crystalline solids has been exploited for stimuli-responsive functions and adaptive behavior11-13. As in the case of such 3D materials, integrating flexibility/adaptiveness into crystalline 2D lattices would greatly broaden the functional scope of 2D materials. Here we report the self-assembly of unsupported, 2D protein lattices with precise spatial arrangements and patterns through a readily accessible design strategy. Three single- or double-point mutants of the C4 symmetric protein RhuA were designed to assemble via different modes of intermolecular interactions (single disulfide, double disulfide and metal coordination) into crystalline 2D arrays. Owing to the flexibility of the single disulfide interactions, the lattices of one of the variants (C98RhuA) are essentially defect-free and undergo substantial but fully correlated changes in molecular arrangement, giving coherently dynamic 2D molecular lattices. Notably, C98RhuA lattices possess a Poisson's ratio of −1, the lowest thermodynamically possible value for an isotropic material. PMID:27135928

Single-camera displacement field correlation method for centrosymmetric 3D dynamic deformation measurement

NASA Astrophysics Data System (ADS)

Zhao, Jiaye; Wen, Huihui; Liu, Zhanwei; Rong, Jili; Xie, Huimin

2018-05-01

Three-dimensional (3D) deformation measurements are a key issue in experimental mechanics. In this paper, a displacement field correlation (DFC) method to measure centrosymmetric 3D dynamic deformation using a single camera is proposed for the first time. When 3D deformation information is collected by a camera at a tilted angle, the measured displacement fields are coupling fields of both the in-plane and out-of-plane displacements. The features of the coupling field are analysed in detail, and a decoupling algorithm based on DFC is proposed. The 3D deformation to be measured can be inverted and reconstructed using only one coupling field. The accuracy of this method was validated by a high-speed impact experiment that simulated an underwater explosion. The experimental results show that the approach proposed in this paper can be used in 3D deformation measurements with higher sensitivity and accuracy, and is especially suitable for high-speed centrosymmetric deformation. In addition, this method avoids the non-synchronisation problem associated with using a pair of high-speed cameras, as is common in 3D dynamic measurements.

Ultrafast Dynamics of Energetic Materials

DTIC Science & Technology

2014-01-23

redistributed in condensed-phase materials. In this subproject we developed a technique termed three-dimensional IR- Raman spectroscopy that allowed us to...Fang, 2011, “The distribution of local enhancement factors in surface enhanced Raman -active substrates and the vibrational dynamics in the liquid phase...3. (invited) “Vibrational energy and molecular thermometers in liquids: Ultrafast IR- Raman spectroscopy”, Brandt C. Pein and Dana D. Dlott, To

Exploring the Roles of Proline in Three-Dimensional Domain Swapping from Structure Analysis and Molecular Dynamics Simulations.

PubMed

Huang, Yongqi; Gao, Meng; Su, Zhengding

2018-02-01

Three-dimensional (3D) domain swapping is a mechanism to form protein oligomers. It has been proposed that several factors, including proline residues in the hinge region, may affect the occurrence of 3D domain swapping. Although introducing prolines into the hinge region has been found to promote domain swapping for some proteins, the opposite effect has also been observed in several studies. So far, how proline affects 3D domain swapping remains elusive. In this work, based on a large set of 3D domain-swapped structures, we performed a systematic analysis to explore the correlation between the presence of proline in the hinge region and the occurrence of 3D domain swapping. We further analyzed the conformations of proline and pre-proline residues to investigate the roles of proline in 3D domain swapping. We found that more than 40% of the domain-swapped structures contained proline residues in the hinge region. Unexpectedly, conformational transitions of proline residues were rarely observed upon domain swapping. Our analyses showed that hinge regions containing proline residues preferred more extended conformations, which may be beneficial for the occurrence of domain swapping by facilitating opening of the exchanged segments.

Electroelastic fields in a layered piezoelectric cylindrical shell under dynamic load

NASA Astrophysics Data System (ADS)

Saviz, M. R.; Shakeri, M.; Yas, M. H.

2007-10-01

The objective of this paper is to demonstrate layerwise theory for the analysis of thick laminated piezoelectric shell structures. A general finite element formulation using the layerwise theory is developed for a laminated cylindrical shell with piezoelectric layers, subjected to dynamic loads. The quadratic approximation of the displacement and electric potential in the thickness direction is considered. The governing equations are reduced to two-dimensional (2D) differential equations. The three-dimensional (3D) elasticity solution is also presented. The resulting equations are solved by a proper finite element method. The numerical results for static loading are compared with exact solutions of benchmark problems. Numerical examples of the dynamic problem are presented. The convergence is studied, as is the influence of the electromechanical coupling on the axisymmetric free-vibration characteristics of a thick cylinder.

Note: "Lock-in accelerometry" to follow sink dynamics in shaken granular matter.

PubMed

Sánchez-Colina, G; Alonso-Llanes, L; Martínez, E; Batista-Leyva, A J; Clement, C; Fliedner, C; Toussaint, R; Altshuler, E

2014-12-01

Understanding the penetration dynamics of intruders in granular beds is relevant not only for fundamental physics, but also for geophysical processes and construction on sediments or granular soils in areas potentially affected by earthquakes. While the penetration of intruders in two dimensional (2D) laboratory granular beds can be followed using video recording, this is useless in three dimensional (3D) beds of non-transparent materials such as common sand. Here, we propose a method to quantify the sink dynamics of an intruder into laterally shaken granular beds based on the temporal correlations between the signals from a reference accelerometer fixed to the shaken granular bed, and a probe accelerometer deployed inside the intruder. Due to its analogy with the working principle of a lock-in amplifier, we call this technique lock-in accelerometry.

Lattice Light Sheet Microscopy: Imaging Molecules to Embryos at High Spatiotemporal Resolution

PubMed Central

Chen, Bi-Chang; Legant, Wesley R.; Wang, Kai; Shao, Lin; Milkie, Daniel E.; Davidson, Michael W.; Janetopoulos, Chris; Wu, Xufeng S.; Hammer, John A.; Liu, Zhe; English, Brian P.; Mimori-Kiyosue, Yuko; Romero, Daniel P.; Ritter, Alex T.; Lippincott-Schwartz, Jennifer; Fritz-Laylin, Lillian; Mullins, R. Dyche; Mitchell, Diana M.; Bembenek, Joshua N.; Reymann, Anne-Cecile; Böhme, Ralph; Grill, Stephan W.; Wang, Jennifer T.; Seydoux, Geraldine; Tulu, U. Serdar; Kiehart, Daniel P.; Betzig, Eric

2015-01-01

Although fluorescence microscopy provides a crucial window into the physiology of living specimens, many biological processes are too fragile, too small, or occur too rapidly to see clearly with existing tools. We crafted ultra-thin light sheets from two-dimensional optical lattices that allowed us to image three-dimensional (3D) dynamics for hundreds of volumes, often at sub-second intervals, at the diffraction limit and beyond. We applied this to systems spanning four orders of magnitude in space and time, including the diffusion of single transcription factor molecules in stem cell spheroids, the dynamic instability of mitotic microtubules, the immunological synapse, neutrophil motility in a 3D matrix, and embryogenesis in Caenorhabditis elegans and Drosophila melanogaster. The results provide a visceral reminder of the beauty and complexity of living systems. PMID:25342811

Modeling hydrodynamics, water quality, and benthic processes to predict ecological effects in Narragansett Bay

EPA Science Inventory

The environmental fluid dynamics code (EFDC) was used to study the three dimensional (3D) circulation, water quality, and ecology in Narragansett Bay, RI. Predictions of the Bay hydrodynamics included the behavior of the water surface elevation, currents, salinity, and temperatur...

Characterization of 3-Dimensional PET Systems for Accurate Quantification of Myocardial Blood Flow.

PubMed

Renaud, Jennifer M; Yip, Kathy; Guimond, Jean; Trottier, Mikaël; Pibarot, Philippe; Turcotte, Eric; Maguire, Conor; Lalonde, Lucille; Gulenchyn, Karen; Farncombe, Troy; Wisenberg, Gerald; Moody, Jonathan; Lee, Benjamin; Port, Steven C; Turkington, Timothy G; Beanlands, Rob S; deKemp, Robert A

2017-01-01

Three-dimensional (3D) mode imaging is the current standard for PET/CT systems. Dynamic imaging for quantification of myocardial blood flow with short-lived tracers, such as 82 Rb-chloride, requires accuracy to be maintained over a wide range of isotope activities and scanner counting rates. We proposed new performance standard measurements to characterize the dynamic range of PET systems for accurate quantitative imaging. 82 Rb or 13 N-ammonia (1,100-3,000 MBq) was injected into the heart wall insert of an anthropomorphic torso phantom. A decaying isotope scan was obtained over 5 half-lives on 9 different 3D PET/CT systems and 1 3D/2-dimensional PET-only system. Dynamic images (28 × 15 s) were reconstructed using iterative algorithms with all corrections enabled. Dynamic range was defined as the maximum activity in the myocardial wall with less than 10% bias, from which corresponding dead-time, counting rates, and/or injected activity limits were established for each scanner. Scatter correction residual bias was estimated as the maximum cavity blood-to-myocardium activity ratio. Image quality was assessed via the coefficient of variation measuring nonuniformity of the left ventricular myocardium activity distribution. Maximum recommended injected activity/body weight, peak dead-time correction factor, counting rates, and residual scatter bias for accurate cardiac myocardial blood flow imaging were 3-14 MBq/kg, 1.5-4.0, 22-64 Mcps singles and 4-14 Mcps prompt coincidence counting rates, and 2%-10% on the investigated scanners. Nonuniformity of the myocardial activity distribution varied from 3% to 16%. Accurate dynamic imaging is possible on the 10 3D PET systems if the maximum injected MBq/kg values are respected to limit peak dead-time losses during the bolus first-pass transit. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

The northern tidal dynamic of Aceh waters: A 3D numerical model

NASA Astrophysics Data System (ADS)

Irham, M.; Miswar, E.; Ilhamsyah, Y.; Setiawan, I.

2018-05-01

The northern tidal dynamic of Aceh waters studied by employing three-dimensional (3D) numerical hydrodynamic model. The purpose of this study is to understand the phenomena and the characteristic of the northern tidal dynamic of Aceh waters. The research used the explicit-splitting scheme numerical model of Navier-Stokes formulation. The result displays that the vertical rotation of flow movement (vertical eddy) at a depth of 15 to 25 meter eastern part of the study area. Hence, the result also informs that the current circulation identically to the upwelling in the western region of Aceh during the wet season and vice versa. However, during the transitional season, the flow circulation depends on how the tidal dynamic occurs in the area.

Attractors of three-dimensional fast-rotating Navier-Stokes equations

NASA Astrophysics Data System (ADS)

Trahe, Markus

The three-dimensional (3-D) rotating Navier-Stokes equations describe the dynamics of rotating, incompressible, viscous fluids. In this work, they are considered with smooth, time-independent forces and the original statements implied by the classical "Taylor-Proudman Theorem" of geophysics are rigorously proved. It is shown that fully developed turbulence of 3-D fast-rotating fluids is essentially characterized by turbulence of two-dimensional (2-D) fluids in terms of numbers of degrees of freedom. In this context, the 3-D nonlinear "resonant limit equations", which arise in a non-linear averaging process as the rotation frequency O → infinity, are studied and optimal (2-D-type) upper bounds for fractal box and Hausdorff dimensions of the global attractor as well as upper bounds for box dimensions of exponential attractors are determined. Then, the convergence of exponential attractors for the full 3-D rotating Navier-Stokes equations to exponential attractors for the resonant limit equations as O → infinity in the sense of full Hausdorff-metric distances is established. This provides upper and lower semi-continuity of exponential attractors with respect to the rotation frequency and implies that the number of degrees of freedom (attractor dimension) of 3-D fast-rotating fluids is close to that of 2-D fluids. Finally, the algebraic-geometric structure of the Poincare curves, which control the resonances and small divisor estimates for partial differential equations, is further investigated; the 3-D nonlinear limit resonant operators are characterized by three-wave interactions governed by these curves. A new canonical transformation between those curves is constructed; with far-reaching consequences on the density of the latter.

A three-dimensional model of co-rotating streams in the solar wind. 2: Hydrodynamic streams

NASA Technical Reports Server (NTRS)

Pizzo, V. J.

1979-01-01

Theoretical aspects of corotating solar wind dynamics on a global scale are explored by means of numerical simulations executed with a nonlinear, inviscid, adiabatic, single-fluid, three-dimensional (3-D) hydrodynamic formulation. A simple, hypothetical 3-D stream structure is defined on a source surface located at 35 solar radius and carefully documents its evolution to 1 AU under the influence of solar rotation. By manipulating the structure of this prototype configuration at the source surface, it is possible to elucidate the factors most strongly affecting stream evolution: (1) the intrinsic correlations among density, temperature, and velocity existing near the source; (2) the amplitude of the stream; (3) the longitudinal breadth of the stream; (4) the latitudinal breadth of the stream; and (5) the heliographic latitude of the centroid of the stream.

3D Magnetic Reconnection

NASA Astrophysics Data System (ADS)

Parnell, Clare E.; Maclean, Rhona C.; Haynes, Andrew L.; Galsgaard, Klaus

2011-08-01

Magnetic reconnection is an important process that is prevalent in a wide range of astrophysical bodies. It is the mechanism that permits magnetic fields to relax to a lower energy state through the global restructuring of the magnetic field and is thus associated with a range of dynamic phenomena such as solar flares and CMEs. The characteristics of three-dimensional reconnection are reviewed revealing how much more diverse it is than reconnection in two dimensions. For instance, three-dimensional reconnection can occur both in the vicinity of null points, as well as in the absence of them. It occurs continuously and continually throughout a diffusion volume, as opposed to at a single point, as it does in two dimensions. This means that in three-dimensions field lines do not reconnect in pairs of lines making the visualisation and interpretation of three-dimensional reconnection difficult. By considering particular numerical 3D magnetohydrodynamic models of reconnection, we consider how magnetic reconnection can lead to complex magnetic topologies and current sheet formation. Indeed, it has been found that even simple interactions, such as the emergence of a flux tube, can naturally give rise to `turbulent-like' reconnection regions.

Development of three-dimensional memory (3D-M)

NASA Astrophysics Data System (ADS)

Yu, Hong-Yu; Shen, Chen; Jiang, Lingli; Dong, Bin; Zhang, Guobiao

2016-10-01

Since the invention of 3-D ROM in 1996, three-dimensional memory (3D-M) has been under development for nearly two decades. In this presentation, we'll review the 3D-M history and compare different 3D-Ms (including 3D-OTP from Matrix Semiconductor, 3D-NAND from Samsung and 3D-XPoint from Intel/Micron).

Space shuttle main engine numerical modeling code modifications and analysis

NASA Technical Reports Server (NTRS)

Ziebarth, John P.

1988-01-01

The user of computational fluid dynamics (CFD) codes must be concerned with the accuracy and efficiency of the codes if they are to be used for timely design and analysis of complicated three-dimensional fluid flow configurations. A brief discussion of how accuracy and efficiency effect the CFD solution process is given. A more detailed discussion of how efficiency can be enhanced by using a few Cray Research Inc. utilities to address vectorization is presented and these utilities are applied to a three-dimensional Navier-Stokes CFD code (INS3D).

Implementation of a 3D mixing layer code on parallel computers

NASA Technical Reports Server (NTRS)

Roe, K.; Thakur, R.; Dang, T.; Bogucz, E.

1995-01-01

This paper summarizes our progress and experience in the development of a Computational-Fluid-Dynamics code on parallel computers to simulate three-dimensional spatially-developing mixing layers. In this initial study, the three-dimensional time-dependent Euler equations are solved using a finite-volume explicit time-marching algorithm. The code was first programmed in Fortran 77 for sequential computers. The code was then converted for use on parallel computers using the conventional message-passing technique, while we have not been able to compile the code with the present version of HPF compilers.

Effective equations for matter-wave gap solitons in higher-order transversal states.

PubMed

Mateo, A Muñoz; Delgado, V

2013-10-01

We demonstrate that an important class of nonlinear stationary solutions of the three-dimensional (3D) Gross-Pitaevskii equation (GPE) exhibiting nontrivial transversal configurations can be found and characterized in terms of an effective one-dimensional (1D) model. Using a variational approach we derive effective equations of lower dimensionality for BECs in (m,n(r)) transversal states (states featuring a central vortex of charge m as well as n(r) concentric zero-density rings at every z plane) which provides us with a good approximate solution of the original 3D problem. Since the specifics of the transversal dynamics can be absorbed in the renormalization of a couple of parameters, the functional form of the equations obtained is universal. The model proposed finds its principal application in the study of the existence and classification of 3D gap solitons supported by 1D optical lattices, where in addition to providing a good estimate for the 3D wave functions it is able to make very good predictions for the μ(N) curves characterizing the different fundamental families. We have corroborated the validity of our model by comparing its predictions with those from the exact numerical solution of the full 3D GPE.

The three-dimensional Event-Driven Graphics Environment (3D-EDGE)

NASA Technical Reports Server (NTRS)

Freedman, Jeffrey; Hahn, Roger; Schwartz, David M.

1993-01-01

Stanford Telecom developed the Three-Dimensional Event-Driven Graphics Environment (3D-EDGE) for NASA GSFC's (GSFC) Communications Link Analysis and Simulation System (CLASS). 3D-EDGE consists of a library of object-oriented subroutines which allow engineers with little or no computer graphics experience to programmatically manipulate, render, animate, and access complex three-dimensional objects.

3-D scapular kinematics during arm elevation: effect of motion velocity.

PubMed

Fayad, F; Hoffmann, G; Hanneton, S; Yazbeck, C; Lefevre-Colau, M M; Poiraudeau, S; Revel, M; Roby-Brami, A

2006-11-01

No three-dimensional (3-D) data exist on the influence of motion velocity on scapular kinematics. The effect of arm elevation velocity has been studied only in a two-dimensional setting. Thirty healthy subjects performed dominant (right) arm elevation in two planes, sagittal and frontal, and at slow and fast self-selected arm speed. Scapular orientation and humeral elevation were measured at 30 Hz recording frequency with use of a 6-degree-of-freedom electromagnetic system (Polhemus Fastraka). Motion was computed according to the International Society of Biomechanics standards. Scapular orientation was also determined with the arm held in different static positions. We obtained a full 3-D kinematic description of scapula achieving a reliable, complex 3-D motion during humeral elevation and lowering. The maximal sagittal arm elevation showed a characteristic "M"-shape pattern of protraction/retraction curve. Scapular rotations did not differ significantly between slow and fast movements. Moreover, protraction/retraction and tilt angular values did not differ significantly between static and dynamic tasks. However, scapular lateral rotation values differed between static and dynamic measurements during sagittal and frontal arm elevation. Lateral scapular rotation appears to be less in static than in dynamic measurement, particularly in the sagittal plane. Interpolation of statically recorded positions of the bones cannot reflect the kinematics of the scapula.

Two-Dimensional SiO2/VO2 Photonic Crystals with Statically Visible and Dynamically Infrared Modulated for Smart Window Deployment.

PubMed

Ke, Yujie; Balin, Igal; Wang, Ning; Lu, Qi; Tok, Alfred Iing Yoong; White, Timothy J; Magdassi, Shlomo; Abdulhalim, Ibrahim; Long, Yi

2016-12-07

Two-dimensional (2D) photonic structures, widely used for generating photonic band gaps (PBG) in a variety of materials, are for the first time integrated with the temperature-dependent phase change of vanadium dioxide (VO 2 ). VO 2 possesses thermochromic properties, whose potential remains unrealized due to an undesirable yellow-brown color. Here, a SiO 2 /VO 2 core/shell 2D photonic crystal is demonstrated to exhibit static visible light tunability and dynamic near-infrared (NIR) modulation. Three-dimensional (3D) finite difference time domain (FDTD) simulations predict that the transmittance can be tuned across the visible spectrum, while maintaining good solar regulation efficiency (ΔT sol = 11.0%) and high solar transmittance (T lum = 49.6%). Experiments show that the color changes of VO 2 films are accompanied by NIR modulation. This work presents a novel way to manipulate VO 2 photonic structures to modulate light transmission as a function of wavelength at different temperatures.

Structure, stability, thermodynamic properties, and infrared spectra of the protonated water octamer H(+)(H2O)8.

PubMed

Karthikeyan, S; Park, Mina; Shin, Ilgyou; Kim, Kwang S

2008-10-16

We investigated various two-dimensional (2D) and three-dimensional (3D) structures of H (+)(H 2O) 8, using density functional theory (DFT), Moller-Plesset second-order perturbation theory (MP2), and coupled cluster theory with single, double, and perturbative triple excitations (CCSD(T)). The 3D structure is more stable than the 2D structure at all levels of theory on the Born-Oppenheimer surface. With the zero-point energy (ZPE) correction, the predicted structure varies depending on the level of theory. The DFT employing Becke's three parameters with Lee-Yang-Parr functionals (B3LYP) favors the 2D structure. At the complete basis set (CBS) limit, the MP2 calculation favors the 3D structure by 0.29 kcal/mol, and the CCSD(T) calculation favors the 3D structure by 0.27 kcal/mol. It is thus expected that both 2D and 3D structures are nearly isoenergetic near 0 K. At 100 K, all the calculations show that the 2D structure is much more stable in free binding energy than the 3D structure. The DFT and MP2 vibrational spectra of the 2D structure are consistent with the experimental spectra. First-principles Car-Parrinello molecular dynamics (CPMD) simulations show that the 2D Zundel-type vibrational spectra are in good agreement with the experiment.

3DScapeCS: application of three dimensional, parallel, dynamic network visualization in Cytoscape

PubMed Central

2013-01-01

Background The exponential growth of gigantic biological data from various sources, such as protein-protein interaction (PPI), genome sequences scaffolding, Mass spectrometry (MS) molecular networking and metabolic flux, demands an efficient way for better visualization and interpretation beyond the conventional, two-dimensional visualization tools. Results We developed a 3D Cytoscape Client/Server (3DScapeCS) plugin, which adopted Cytoscape in interpreting different types of data, and UbiGraph for three-dimensional visualization. The extra dimension is useful in accommodating, visualizing, and distinguishing large-scale networks with multiple crossed connections in five case studies. Conclusions Evaluation on several experimental data using 3DScapeCS and its special features, including multilevel graph layout, time-course data animation, and parallel visualization has proven its usefulness in visualizing complex data and help to make insightful conclusions. PMID:24225050

Three-Dimensional Road Network by Fusion of Polarimetric and Interferometric SAR Data

NASA Technical Reports Server (NTRS)

Gamba, P.; Houshmand, B.

1998-01-01

In this paper a fuzzy classification procedure is applied to polarimetric radar measurements, and street pixels are detected. These data are successively grouped into consistent roads by means of a dynamic programming approach based on the fuzzy membership function values. Further fusion of the 2D road network extracted and 3D TOPSAR measurements provides a powerful way to analyze urban infrastructures.

Feedback-based, system-level properties of vertebrate-microbial interactions.

PubMed

Rivas, Ariel L; Jankowski, Mark D; Piccinini, Renata; Leitner, Gabriel; Schwarz, Daniel; Anderson, Kevin L; Fair, Jeanne M; Hoogesteijn, Almira L; Wolter, Wilfried; Chaffer, Marcelo; Blum, Shlomo; Were, Tom; Konah, Stephen N; Kempaiah, Prakash; Ong'echa, John M; Diesterbeck, Ulrike S; Pilla, Rachel; Czerny, Claus-Peter; Hittner, James B; Hyman, James M; Perkins, Douglas J

2013-01-01

Improved characterization of infectious disease dynamics is required. To that end, three-dimensional (3D) data analysis of feedback-like processes may be considered. To detect infectious disease data patterns, a systems biology (SB) and evolutionary biology (EB) approach was evaluated, which utilizes leukocyte data structures designed to diminish data variability and enhance discrimination. Using data collected from one avian and two mammalian (human and bovine) species infected with viral, parasite, or bacterial agents (both sensitive and resistant to antimicrobials), four data structures were explored: (i) counts or percentages of a single leukocyte type, such as lymphocytes, neutrophils, or macrophages (the classic approach), and three levels of the SB/EB approach, which assessed (ii) 2D, (iii) 3D, and (iv) multi-dimensional (rotating 3D) host-microbial interactions. In all studies, no classic data structure discriminated disease-positive (D+, or observations in which a microbe was isolated) from disease-negative (D-, or microbial-negative) groups: D+ and D- data distributions overlapped. In contrast, multi-dimensional analysis of indicators designed to possess desirable features, such as a single line of observations, displayed a continuous, circular data structure, whose abrupt inflections facilitated partitioning into subsets statistically significantly different from one another. In all studies, the 3D, SB/EB approach distinguished three (steady, positive, and negative) feedback phases, in which D- data characterized the steady state phase, and D+ data were found in the positive and negative phases. In humans, spatial patterns revealed false-negative observations and three malaria-positive data classes. In both humans and bovines, methicillin-resistant Staphylococcus aureus (MRSA) infections were discriminated from non-MRSA infections. More information can be extracted, from the same data, provided that data are structured, their 3D relationships are considered, and well-conserved (feedback-like) functions are estimated. Patterns emerging from such structures may distinguish well-conserved from recently developed host-microbial interactions. Applications include diagnosis, error detection, and modeling.

Skin-Friction Measurements in a 3-D, Supersonic Shock-Wave/Boundary-Layer Interaction

NASA Technical Reports Server (NTRS)

Wideman, J. K.; Brown, J. L.; Miles, J. B.; Ozcan, O.

1994-01-01

The experimental documentation of a three-dimensional shock-wave/boundary-layer interaction in a nominal Mach 3 cylinder, aligned with the free-stream flow, and 20 deg. half-angle conical flare offset 1.27 cm from the cylinder centerline. Surface oil flow, laser light sheet illumination, and schlieren were used to document the flow topology. The data includes surface-pressure and skin-friction measurements. A laser interferometric skin friction data. Included in the skin-friction data are measurements within separated regions and three-dimensional measurements in highly-swept regions. The skin-friction data will be particularly valuable in turbulence modeling and computational fluid dynamics validation.

Contrast-enhanced time-resolved 4D MRA of congenital heart and vessel anomalies: image quality and diagnostic value compared with 3D MRA.

PubMed

Vogt, Florian M; Theysohn, Jens M; Michna, Dariusz; Hunold, Peter; Neudorf, Ulrich; Kinner, Sonja; Barkhausen, Jörg; Quick, Harald H

2013-09-01

To evaluate time-resolved interleaved stochastic trajectories (TWIST) contrast-enhanced 4D magnetic resonance angiography (MRA) and compare it with 3D FLASH MRA in patients with congenital heart and vessel anomalies. Twenty-six patients with congenital heart and vessel anomalies underwent contrast-enhanced MRA with both 3D FLASH and 4D TWIST MRA. Images were subjectively evaluated regarding total image quality, artefacts, diagnostic value and added diagnostic value of 4D dynamic imaging. Quantitative comparison included signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and vessel sharpness measurements. Three-dimensional FLASH MRA was judged to be significantly better in terms of image quality (4.0 ± 0.6 vs 3.4 ± 0.6, P < 0.05) and artefacts (3.8 ± 0.4 vs 3.3 ± 0.5, P < 0.05); no difference in diagnostic value was found (4.2 ± 0.4 vs 4.0 ± 0.4); important additional functional information was found in 21/26 patients. SNR and CNR were higher in the pulmonary trunk in 4D TWIST, but slightly higher in the systemic arteries in 3D FLASH. No difference in vessel sharpness delineation was found. Although image quality was inferior compared with 3D FLASH MRA, 4D TWIST MRA yields robust images and added diagnostic value through dynamic acquisition was found. Thus, 4D TWIST MRA is an attractive alternative to 3D FLASH MRA. • New magnetic resonance angiography (MRA) techniques are increasingly introduced for congenital cardiovascular problems. • Time-resolved angiography with interleaved stochastic trajectories (TWIST) is an example. • Four-dimensional TWIST MRA provided inferior image quality compared to 3D FLASH MRA but without significant difference in vessel sharpness. • Four-dimensional TWIST MRA gave added diagnostic value.

Analysis of the diffraction effects for a multi-view autostereoscopic three-dimensional display system based on shutter parallax barriers with full resolution

NASA Astrophysics Data System (ADS)

Meng, Yang; Yu, Zhongyuan; Jia, Fangda; Zhang, Chunyu; Wang, Ye; Liu, Yumin; Ye, Han; Chen, Laurence Lujun

2017-10-01

A multi-view autostereoscopic three-dimensional (3D) system is built by using a 2D display screen and a customized parallax-barrier shutter (PBS) screen. The shutter screen is controlled dynamically by address driving matrix circuit and it is placed in front of the display screen at a certain location. The system could achieve densest viewpoints due to its specially optical and geometric design which is based on concept of "eye space". The resolution of 3D imaging is not reduced compared to 2D mode by using limited time division multiplexing technology. The diffraction effects may play an important role in 3D display imaging quality, especially when applied to small screen, such as iPhone screen etc. For small screen, diffraction effects may contribute crosstalk between binocular views, image brightness uniformity etc. Therefore, diffraction effects are analyzed and considered in a one-dimensional shutter screen model of the 3D display, in which the numerical simulation of light from display pixels on display screen through parallax barrier slits to each viewing zone in eye space, is performed. The simulation results provide guidance for criteria screen size over which the impact of diffraction effects are ignorable, and below which diffraction effects must be taken into account. Finally, the simulation results are compared to the corresponding experimental measurements and observation with discussion.

Vibro-acoustic modeling and analysis of a coupled acoustic system comprising a partially opened cavity coupled with a flexible plate

NASA Astrophysics Data System (ADS)

Shi, Shuangxia; Su, Zhu; Jin, Guoyong; Liu, Zhigang

2018-01-01

This paper is concerned with the modeling and solution method of a three-dimensional (3D) coupled acoustic system comprising a partially opened cavity coupled with a flexible plate and an exterior field of semi-infinite size, which is ubiquitously encountered in architectural acoustics and is a reasonable representation of many engineering occasions. A general solution method is presented to predict the dynamic behaviors of the three-dimensional (3D) acoustic coupled system, in which the displacement of the plate and the sound pressure in the cavity are respectively constructed in the form of the two-dimensional and three-dimensional modified Fourier series with several auxiliary functions introduced to ensure the uniform convergence of the solution over the entire solution domain. The effect of the opening is taken into account via the work done by the sound pressure acting at the coupling aperture that is contributed from the vibration of particles on the acoustic coupling interface and on the structural-acoustic coupling interface. Both the acoustic coupling between finite cavity and exterior field and the structural-acoustic coupling between flexible plate and interior acoustic field are considered in the vibro-acoustic modeling of the three-dimensional acoustic coupled acoustic system. The dynamic responses of the coupled structural-acoustic system are obtained using the Rayleigh-Ritz procedure based on the energy expressions for the coupled system. The accuracy and effectiveness of the proposed method are validated through numerical examples and comparison with results obtained by the boundary element analysis. Furthermore, the influence of the opening and the cavity volume on the acoustic behaviors of opened cavity system is studied.

Steady-State Computation of Constant Rotational Rate Dynamic Stability Derivatives

NASA Technical Reports Server (NTRS)

Park, Michael A.; Green, Lawrence L.

2000-01-01

Dynamic stability derivatives are essential to predicting the open and closed loop performance, stability, and controllability of aircraft. Computational determination of constant-rate dynamic stability derivatives (derivatives of aircraft forces and moments with respect to constant rotational rates) is currently performed indirectly with finite differencing of multiple time-accurate computational fluid dynamics solutions. Typical time-accurate solutions require excessive amounts of computational time to complete. Formulating Navier-Stokes (N-S) equations in a rotating noninertial reference frame and applying an automatic differentiation tool to the modified code has the potential for directly computing these derivatives with a single, much faster steady-state calculation. The ability to rapidly determine static and dynamic stability derivatives by computational methods can benefit multidisciplinary design methodologies and reduce dependency on wind tunnel measurements. The CFL3D thin-layer N-S computational fluid dynamics code was modified for this study to allow calculations on complex three-dimensional configurations with constant rotation rate components in all three axes. These CFL3D modifications also have direct application to rotorcraft and turbomachinery analyses. The modified CFL3D steady-state calculation is a new capability that showed excellent agreement with results calculated by a similar formulation. The application of automatic differentiation to CFL3D allows the static stability and body-axis rate derivatives to be calculated quickly and exactly.

Static and dynamic crystalline lens accommodation evaluated using quantitative 3-D OCT.

PubMed

Gambra, Enrique; Ortiz, Sergio; Perez-Merino, Pablo; Gora, Michalina; Wojtkowski, Maciej; Marcos, Susana

2013-01-01

Custom high-resolution high-speed anterior segment spectral domain Optical Coherence Tomography (OCT) provided with automatic quantification and distortion correction algorithms was used to characterize three-dimensionally (3-D) the human crystalline lens in vivo in four subjects, for accommodative demands between 0 to 6 D in 1 D steps. Anterior and posterior lens radii of curvature decreased with accommodative demand at rates of 0.73 and 0.20 mm/D, resulting in an increase of the estimated optical power of the eye of 0.62 D per diopter of accommodative demand. Dynamic fluctuations in crystalline lens radii of curvature, anterior chamber depth and lens thickness were also estimated from dynamic 2-D OCT images (14 Hz), acquired during 5-s of steady fixation, for different accommodative demands. Estimates of the eye power from dynamical geometrical measurements revealed an increase of the fluctuations of the accommodative response from 0.07 D to 0.47 D between 0 and 6 D (0.044 D per D of accommodative demand). A sensitivity analysis showed that the fluctuations of accommodation were driven by dynamic changes in the lens surfaces, particularly in the posterior lens surface.

Static and dynamic crystalline lens accommodation evaluated using quantitative 3-D OCT

PubMed Central

Gambra, Enrique; Ortiz, Sergio; Perez-Merino, Pablo; Gora, Michalina; Wojtkowski, Maciej; Marcos, Susana

2013-01-01

Custom high-resolution high-speed anterior segment spectral domain Optical Coherence Tomography (OCT) provided with automatic quantification and distortion correction algorithms was used to characterize three-dimensionally (3-D) the human crystalline lens in vivo in four subjects, for accommodative demands between 0 to 6 D in 1 D steps. Anterior and posterior lens radii of curvature decreased with accommodative demand at rates of 0.73 and 0.20 mm/D, resulting in an increase of the estimated optical power of the eye of 0.62 D per diopter of accommodative demand. Dynamic fluctuations in crystalline lens radii of curvature, anterior chamber depth and lens thickness were also estimated from dynamic 2-D OCT images (14 Hz), acquired during 5-s of steady fixation, for different accommodative demands. Estimates of the eye power from dynamical geometrical measurements revealed an increase of the fluctuations of the accommodative response from 0.07 D to 0.47 D between 0 and 6 D (0.044 D per D of accommodative demand). A sensitivity analysis showed that the fluctuations of accommodation were driven by dynamic changes in the lens surfaces, particularly in the posterior lens surface. PMID:24049680

Building the 3D Geological Model of Wall Rock of Salt Caverns Based on Integration Method of Multi-source data

NASA Astrophysics Data System (ADS)

Yongzhi, WANG; hui, WANG; Lixia, LIAO; Dongsen, LI

2017-02-01

In order to analyse the geological characteristics of salt rock and stability of salt caverns, rough three-dimensional (3D) models of salt rock stratum and the 3D models of salt caverns on study areas are built by 3D GIS spatial modeling technique. During implementing, multi-source data, such as basic geographic data, DEM, geological plane map, geological section map, engineering geological data, and sonar data are used. In this study, the 3D spatial analyzing and calculation methods, such as 3D GIS intersection detection method in three-dimensional space, Boolean operations between three-dimensional space entities, three-dimensional space grid discretization, are used to build 3D models on wall rock of salt caverns. Our methods can provide effective calculation models for numerical simulation and analysis of the creep characteristics of wall rock in salt caverns.

Lagrangian transport in a class of three-dimensional buoyancy-driven flows

NASA Astrophysics Data System (ADS)

Contreras, Sebastian; Speetjens, Michel; Clercx, Herman

2017-11-01

The study concerns the Lagrangian dynamics of three-dimensional (3D) buoyancy-driven cavity flows under steady and laminar conditions due to a global temperature gradient imposed via an opposite hot and cold sidewall. This serves as archetypal configuration for natural-convection flows in which gravity is perpendicular to the global temperature gradient. Limited insight into the Lagrangian properties of this class of flows motivates this study. The 3D Lagrangian dynamics are investigated in terms of the generic structure of the Lagrangian flow topology that is described in terms of the Grashof number (Gr) and the Prandtl number (Pr). Gr is the principal control parameter for the flow topology: vanishing Gr yields a state of closed streamlines (integrable state); increasing Gr causes the formation of toroidal coherent structures embedded in chaotic streamlines governed by Hamiltonian mechanisms. Fluid inertia prevails for ``smaller'' Gr. A buoyancy-induced bifurcation of the flow topology occurs for ``larger'' Gr and underlies the emergence of ``secondary rolls'' and secondary tori for ``larger'' Pr. Stagnation points and corresponding manifold interactions are key to the dynamics. S.C. acknowledges financial support from Consejo Nacional de Ciencia y Tecnología (CONACYT).

Large depth of focus dynamic micro integral imaging for optical see-through augmented reality display using a focus-tunable lens.

PubMed

Shen, Xin; Javidi, Bahram

2018-03-01

We have developed a three-dimensional (3D) dynamic integral-imaging (InIm)-system-based optical see-through augmented reality display with enhanced depth range of a 3D augmented image. A focus-tunable lens is adopted in the 3D display unit to relay the elemental images with various positions to the micro lens array. Based on resolution priority integral imaging, multiple lenslet image planes are generated to enhance the depth range of the 3D image. The depth range is further increased by utilizing both the real and virtual 3D imaging fields. The 3D reconstructed image and the real-world scene are overlaid using an optical see-through display for augmented reality. The proposed system can significantly enhance the depth range of a 3D reconstructed image with high image quality in the micro InIm unit. This approach provides enhanced functionality for augmented information and adjusts the vergence-accommodation conflict of a traditional augmented reality display.

Three-dimensional biomechanical properties of human vocal folds: parameter optimization of a numerical model to match in vitro dynamics.

PubMed

Yang, Anxiong; Berry, David A; Kaltenbacher, Manfred; Döllinger, Michael

2012-02-01

The human voice signal originates from the vibrations of the two vocal folds within the larynx. The interactions of several intrinsic laryngeal muscles adduct and shape the vocal folds to facilitate vibration in response to airflow. Three-dimensional vocal fold dynamics are extracted from in vitro hemilarynx experiments and fitted by a numerical three-dimensional-multi-mass-model (3DM) using an optimization procedure. In this work, the 3DM dynamics are optimized over 24 experimental data sets to estimate biomechanical vocal fold properties during phonation. Accuracy of the optimization is verified by low normalized error (0.13 ± 0.02), high correlation (83% ± 2%), and reproducible subglottal pressure values. The optimized, 3DM parameters yielded biomechanical variations in tissue properties along the vocal fold surface, including variations in both the local mass and stiffness of vocal folds. That is, both mass and stiffness increased along the superior-to-inferior direction. These variations were statistically analyzed under different experimental conditions (e.g., an increase in tension as a function of vocal fold elongation and an increase in stiffness and a decrease in mass as a function of glottal airflow). The study showed that physiologically relevant vocal fold tissue properties, which cannot be directly measured during in vivo human phonation, can be captured using this 3D-modeling technique. © 2012 Acoustical Society of America

Three-dimensional biomechanical properties of human vocal folds: Parameter optimization of a numerical model to match in vitro dynamics

PubMed Central

Yang, Anxiong; Berry, David A.; Kaltenbacher, Manfred; Döllinger, Michael

2012-01-01

The human voice signal originates from the vibrations of the two vocal folds within the larynx. The interactions of several intrinsic laryngeal muscles adduct and shape the vocal folds to facilitate vibration in response to airflow. Three-dimensional vocal fold dynamics are extracted from in vitro hemilarynx experiments and fitted by a numerical three-dimensional-multi-mass-model (3DM) using an optimization procedure. In this work, the 3DM dynamics are optimized over 24 experimental data sets to estimate biomechanical vocal fold properties during phonation. Accuracy of the optimization is verified by low normalized error (0.13 ± 0.02), high correlation (83% ± 2%), and reproducible subglottal pressure values. The optimized, 3DM parameters yielded biomechanical variations in tissue properties along the vocal fold surface, including variations in both the local mass and stiffness of vocal folds. That is, both mass and stiffness increased along the superior-to-inferior direction. These variations were statistically analyzed under different experimental conditions (e.g., an increase in tension as a function of vocal fold elongation and an increase in stiffness and a decrease in mass as a function of glottal airflow). The study showed that physiologically relevant vocal fold tissue properties, which cannot be directly measured during in vivo human phonation, can be captured using this 3D-modeling technique. PMID:22352511

Introducing 3-Dimensional Printing of a Human Anatomic Pathology Specimen: Potential Benefits for Undergraduate and Postgraduate Education and Anatomic Pathology Practice.

PubMed

Mahmoud, Amr; Bennett, Michael

2015-08-01

Three-dimensional (3D) printing, a rapidly advancing technology, is widely applied in fields such as mechanical engineering and architecture. Three-dimensional printing has been introduced recently into medical practice in areas such as reconstructive surgery, as well as in clinical research. Three-dimensionally printed models of anatomic and autopsy pathology specimens can be used for demonstrating pathology entities to undergraduate medical, dental, and biomedical students, as well as for postgraduate training in examination of gross specimens for anatomic pathology residents and pathology assistants, aiding clinicopathological correlation at multidisciplinary team meetings, and guiding reconstructive surgical procedures. To apply 3D printing in anatomic pathology for teaching, training, and clinical correlation purposes. Multicolored 3D printing of human anatomic pathology specimens was achieved using a ZCorp 510 3D printer (3D Systems, Rock Hill, South Carolina) following creation of a 3D model using Autodesk 123D Catch software (Autodesk, Inc, San Francisco, California). Three-dimensionally printed models of anatomic pathology specimens created included pancreatoduodenectomy (Whipple operation) and radical nephrectomy specimens. The models accurately depicted the topographic anatomy of selected specimens and illustrated the anatomic relation of excised lesions to adjacent normal tissues. Three-dimensional printing of human anatomic pathology specimens is achievable. Advances in 3D printing technology may further improve the quality of 3D printable anatomic pathology specimens.

3D dust clouds (Yukawa Balls) in strongly coupled dusty plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melzer, A.; Passvogel, M.; Miksch, T.

2010-06-16

Three-dimensional finite systems of charged dust particles confined to concentric spherical shells in a dusty plasma, so-called 'Yukawa balls', have been studied with respect to their static and dynamic properties. Here, we review the charging of particles in a dusty plasma discharge by computer simulations and the respective particle arrangements. The normal mode spectrum of Yukawa balls is measured from the 3D thermal Brownian motion of the dust particles around their equilibrium positions.

Three-dimensional motion-picture imaging of dynamic object by parallel-phase-shifting digital holographic microscopy using an inverted magnification optical system

NASA Astrophysics Data System (ADS)

Fukuda, Takahito; Shinomura, Masato; Xia, Peng; Awatsuji, Yasuhiro; Nishio, Kenzo; Matoba, Osamu

2017-04-01

We constructed a parallel-phase-shifting digital holographic microscopy (PPSDHM) system using an inverted magnification optical system, and succeeded in three-dimensional (3D) motion-picture imaging for 3D displacement of a microscopic object. In the PPSDHM system, the inverted and afocal magnification optical system consisted of a microscope objective (16.56 mm focal length and 0.25 numerical aperture) and a convex lens (300 mm focal length and 82 mm aperture diameter). A polarization-imaging camera was used to record multiple phase-shifted holograms with a single-shot exposure. We recorded an alum crystal, sinking down in aqueous solution of alum, by the constructed PPSDHM system at 60 frames/s for about 20 s and reconstructed high-quality 3D motion-picture image of the crystal. Then, we calculated amounts of displacement of the crystal from the amounts in the focus plane and the magnifications of the magnification optical system, and obtained the 3D trajectory of the crystal by that amounts.

Three-dimensional data-tracking dynamic optimization simulations of human locomotion generated by direct collocation.

PubMed

Lin, Yi-Chung; Pandy, Marcus G

2017-07-05

The aim of this study was to perform full-body three-dimensional (3D) dynamic optimization simulations of human locomotion by driving a neuromusculoskeletal model toward in vivo measurements of body-segmental kinematics and ground reaction forces. Gait data were recorded from 5 healthy participants who walked at their preferred speeds and ran at 2m/s. Participant-specific data-tracking dynamic optimization solutions were generated for one stride cycle using direct collocation in tandem with an OpenSim-MATLAB interface. The body was represented as a 12-segment, 21-degree-of-freedom skeleton actuated by 66 muscle-tendon units. Foot-ground interaction was simulated using six contact spheres under each foot. The dynamic optimization problem was to find the set of muscle excitations needed to reproduce 3D measurements of body-segmental motions and ground reaction forces while minimizing the time integral of muscle activations squared. Direct collocation took on average 2.7±1.0h and 2.2±1.6h of CPU time, respectively, to solve the optimization problems for walking and running. Model-computed kinematics and foot-ground forces were in good agreement with corresponding experimental data while the calculated muscle excitation patterns were consistent with measured EMG activity. The results demonstrate the feasibility of implementing direct collocation on a detailed neuromusculoskeletal model with foot-ground contact to accurately and efficiently generate 3D data-tracking dynamic optimization simulations of human locomotion. The proposed method offers a viable tool for creating feasible initial guesses needed to perform predictive simulations of movement using dynamic optimization theory. The source code for implementing the model and computational algorithm may be downloaded at http://simtk.org/home/datatracking. Copyright © 2017 Elsevier Ltd. All rights reserved.

Three-dimensional analysis of the early development of the dentition

PubMed Central

Peterkova, R; Hovorakova, M; Peterka, M; Lesot, H

2014-01-01

Tooth development has attracted the attention of researchers since the 19th century. It became obvious even then that morphogenesis could not fully be appreciated from two-dimensional histological sections. Therefore, methods of three-dimensional (3D) reconstructions were employed to visualize the surface morphology of developing structures and to help appreciate the complexity of early tooth morphogenesis. The present review surveys the data provided by computer-aided 3D analyses to update classical knowledge of early odontogenesis in the laboratory mouse and in humans. 3D reconstructions have demonstrated that odontogenesis in the early stages is a complex process which also includes the development of rudimentary odontogenic structures with different fates. Their developmental, evolutionary, and pathological aspects are discussed. The combination of in situ hybridization and 3D reconstruction have demonstrated the temporo-spatial dynamics of the signalling centres that reflect transient existence of rudimentary tooth primordia at loci where teeth were present in ancestors. The rudiments can rescue their suppressed development and revitalize, and then their subsequent autonomous development can give rise to oral pathologies. This shows that tooth-forming potential in mammals can be greater than that observed from their functional dentitions. From this perspective, the mouse rudimentary tooth primordia represent a natural model to test possibilities of tooth regeneration. PMID:24495023

3D annotation and manipulation of medical anatomical structures

NASA Astrophysics Data System (ADS)

Vitanovski, Dime; Schaller, Christian; Hahn, Dieter; Daum, Volker; Hornegger, Joachim

2009-02-01

Although the medical scanners are rapidly moving towards a three-dimensional paradigm, the manipulation and annotation/labeling of the acquired data is still performed in a standard 2D environment. Editing and annotation of three-dimensional medical structures is currently a complex task and rather time-consuming, as it is carried out in 2D projections of the original object. A major problem in 2D annotation is the depth ambiguity, which requires 3D landmarks to be identified and localized in at least two of the cutting planes. Operating directly in a three-dimensional space enables the implicit consideration of the full 3D local context, which significantly increases accuracy and speed. A three-dimensional environment is as well more natural optimizing the user's comfort and acceptance. The 3D annotation environment requires the three-dimensional manipulation device and display. By means of two novel and advanced technologies, Wii Nintendo Controller and Philips 3D WoWvx display, we define an appropriate 3D annotation tool and a suitable 3D visualization monitor. We define non-coplanar setting of four Infrared LEDs with a known and exact position, which are tracked by the Wii and from which we compute the pose of the device by applying a standard pose estimation algorithm. The novel 3D renderer developed by Philips uses either the Z-value of a 3D volume, or it computes the depth information out of a 2D image, to provide a real 3D experience without having some special glasses. Within this paper we present a new framework for manipulation and annotation of medical landmarks directly in three-dimensional volume.

3D-PDR: Three-dimensional photodissociation region code

NASA Astrophysics Data System (ADS)

Bisbas, T. G.; Bell, T. A.; Viti, S.; Yates, J.; Barlow, M. J.

2018-03-01

3D-PDR is a three-dimensional photodissociation region code written in Fortran. It uses the Sundials package (written in C) to solve the set of ordinary differential equations and it is the successor of the one-dimensional PDR code UCL_PDR (ascl:1303.004). Using the HEALpix ray-tracing scheme (ascl:1107.018), 3D-PDR solves a three-dimensional escape probability routine and evaluates the attenuation of the far-ultraviolet radiation in the PDR and the propagation of FIR/submm emission lines out of the PDR. The code is parallelized (OpenMP) and can be applied to 1D and 3D problems.

The XTT Cell Proliferation Assay Applied to Cell Layers Embedded in Three-Dimensional Matrix

PubMed Central

Huyck, Lynn; Ampe, Christophe

2012-01-01

Abstract Cell proliferation, a main target in cancer therapy, is influenced by the surrounding three-dimensional (3D) extracellular matrix (ECM). In vitro drug screening is, thus, optimally performed under conditions in which cells are grown (embedded or trapped) in dense 3D matrices, as these most closely mimic the adhesive and mechanical properties of natural ECM. Measuring cell proliferation under these conditions is, however, technically more challenging compared with two-dimensional (2D) culture and other “3D culture conditions,” such as growth on top of a matrix (pseudo-3D) or in spongy scaffolds with large pore sizes. Consequently, such measurements are only slowly applied on a wider scale. To advance this, we report on the equal quality (dynamic range, background, linearity) of measuring the proliferation of cell layers embedded in dense 3D matrices (collagen, Matrigel) compared with cells in 2D culture using the easy (one-step) and in 2D well-validated, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT)-assay. The comparison stresses the differences in proliferation kinetics and drug sensitivity of matrix-embedded cells versus 2D culture. Using the specific cell-layer-embedded 3D matrix setup, quantitative measurements of cell proliferation and cell invasion are shown to be possible in similar assay conditions, and cytostatic, cytotoxic, and anti-invasive drug effects can thus be reliably determined and compared in physiologically relevant settings. This approach in the 3D matrix holds promise for improving early-stage, high-throughput drug screening, targeting either highly invasive or highly proliferative subpopulations of cancers or both. PMID:22574651

Towards a voxel-based geographic automata for the simulation of geospatial processes

NASA Astrophysics Data System (ADS)

Jjumba, Anthony; Dragićević, Suzana

2016-07-01

Many geographic processes evolve in a three dimensional space and time continuum. However, when they are represented with the aid of geographic information systems (GIS) or geosimulation models they are modelled in a framework of two-dimensional space with an added temporal component. The objective of this study is to propose the design and implementation of voxel-based automata as a methodological approach for representing spatial processes evolving in the four-dimensional (4D) space-time domain. Similar to geographic automata models which are developed to capture and forecast geospatial processes that change in a two-dimensional spatial framework using cells (raster geospatial data), voxel automata rely on the automata theory and use three-dimensional volumetric units (voxels). Transition rules have been developed to represent various spatial processes which range from the movement of an object in 3D to the diffusion of airborne particles and landslide simulation. In addition, the proposed 4D models demonstrate that complex processes can be readily reproduced from simple transition functions without complex methodological approaches. The voxel-based automata approach provides a unique basis to model geospatial processes in 4D for the purpose of improving representation, analysis and understanding their spatiotemporal dynamics. This study contributes to the advancement of the concepts and framework of 4D GIS.

Multicomponent Supramolecular Systems: Self-Organization in Coordination-Driven Self-Assembly

PubMed Central

Zheng, Yao-Rong; Yang, Hai-Bo; Ghosh, Koushik; Zhao, Liang; Stang, Peter J.

2009-01-01

The self-organization of multicomponent supramolecular systems involving a variety of two-dimensional (2-D) polygons and three-dimensional (3-D) cages is presented. Nine self-organizing systems, SS1–SS9, have been studied. Each involving the simultaneous mixing of organoplatinum acceptors and pyridyl donors of varying geometry and their selective self-assembly into three to four specific 2-D (rectangular, triangular, and rhomboid) and/or 3-D (triangular prism and distorted and nondistorted trigonal bipyramidal) supramolecules. The formation of these discrete structures is characterized using NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS). In all cases, the self-organization process is directed by: (1) the geometric information encoded within the molecular subunits and (2) a thermodynamically driven dynamic self-correction process. The result is the selective self-assembly of multiple discrete products from a randomly formed complex. The influence of key experimental variables – temperature and solvent – on the self-correction process and the fidelity of the resulting self-organization systems is also described. PMID:19544512

3D MALDI Mass Spectrometry Imaging of a Single Cell: Spatial Mapping of Lipids in the Embryonic Development of Zebrafish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dueñas, Maria Emilia; Essner, Jeffrey J.; Lee, Young Jin

The zebrafish ( Danio rerio) has been widely used as a model vertebrate system to study lipid metabolism, the roles of lipids in diseases, and lipid dynamics in embryonic development. Here, we applied high-spatial resolution matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry imaging (MSI) to map and visualize the three-dimensional spatial distribution of phospholipid classes, phosphatidylcholine (PC), phosphatidylethanolamines (PE), and phosphatidylinositol (PI), in newly fertilized individual zebrafish embryos. This is the first time MALDI-MSI has been applied for three dimensional chemical imaging of a single cell. PC molecular species are present inside the yolk in addition to the blastodisc, while PE andmore » PI species are mostly absent in the yolk. Two-dimensional MSI was also studied for embryos at different cell stages (1-, 2-, 4-, 8-, and 16-cell stage) to investigate the localization changes of some lipids at various cell developmental stages. Lastly, four different normalization approaches were compared to find reliable relative quantification in 2D- and 3D- MALDI MSI data sets.« less

3D MALDI Mass Spectrometry Imaging of a Single Cell: Spatial Mapping of Lipids in the Embryonic Development of Zebrafish

DOE PAGES

Dueñas, Maria Emilia; Essner, Jeffrey J.; Lee, Young Jin

2017-11-02

The zebrafish ( Danio rerio) has been widely used as a model vertebrate system to study lipid metabolism, the roles of lipids in diseases, and lipid dynamics in embryonic development. Here, we applied high-spatial resolution matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry imaging (MSI) to map and visualize the three-dimensional spatial distribution of phospholipid classes, phosphatidylcholine (PC), phosphatidylethanolamines (PE), and phosphatidylinositol (PI), in newly fertilized individual zebrafish embryos. This is the first time MALDI-MSI has been applied for three dimensional chemical imaging of a single cell. PC molecular species are present inside the yolk in addition to the blastodisc, while PE andmore » PI species are mostly absent in the yolk. Two-dimensional MSI was also studied for embryos at different cell stages (1-, 2-, 4-, 8-, and 16-cell stage) to investigate the localization changes of some lipids at various cell developmental stages. Lastly, four different normalization approaches were compared to find reliable relative quantification in 2D- and 3D- MALDI MSI data sets.« less

A wavelet ridge extraction method employing a novel cost function in two-dimensional wavelet transform profilometry

NASA Astrophysics Data System (ADS)

Wang, Jianhua; Yang, Yanxi

2018-05-01

We present a new wavelet ridge extraction method employing a novel cost function in two-dimensional wavelet transform profilometry (2-D WTP). First of all, the maximum value point is extracted from two-dimensional wavelet transform coefficient modulus, and the local extreme value points over 90% of maximum value are also obtained, they both constitute wavelet ridge candidates. Then, the gradient of rotate factor is introduced into the Abid's cost function, and the logarithmic Logistic model is used to adjust and improve the cost function weights so as to obtain more reasonable value estimation. At last, the dynamic programming method is used to accurately find the optimal wavelet ridge, and the wrapped phase can be obtained by extracting the phase at the ridge. Its advantage is that, the fringe pattern with low signal-to-noise ratio can be demodulated accurately, and its noise immunity will be better. Meanwhile, only one fringe pattern is needed to projected to measured object, so dynamic three-dimensional (3-D) measurement in harsh environment can be realized. Computer simulation and experimental results show that, for the fringe pattern with noise pollution, the 3-D surface recovery accuracy by the proposed algorithm is increased. In addition, the demodulation phase accuracy of Morlet, Fan and Cauchy mother wavelets are compared.

Microfabrication and Test of a Three-Dimensional Polymer Hydro-focusing Unit for Flow Cytometry Applications

NASA Technical Reports Server (NTRS)

Yang, Ren; Feeback, Daniel L.; Wang, Wan-Jun

2005-01-01

This paper details a novel three-dimensional (3D) hydro-focusing micro cell sorter for micro flow cytometry applications. The unit was microfabricated by means of SU-8 3D lithography. The 3D microstructure for coaxial sheathing was designed, microfabricated, and tested. Three-dimensional hydrofocusing capability was demonstrated with an experiment to sort labeled tanned sheep erythrocytes (red blood cells). This polymer hydro-focusing microstructure is easily microfabricated and integrated with other polymer microfluidic structures. Keywords: SU-8, three-dimensional hydro-focusing, microfluidic, microchannel, cytometer

THREE-DIMENSIONAL RANDOM ACCESS MULTIPHOTON MICROSCOPY FOR FAST FUNCTIONAL IMAGING OF NEURONAL ACTIVITY

PubMed Central

Reddy, Gaddum Duemani; Kelleher, Keith; Fink, Rudy; Saggau, Peter

2009-01-01

The dynamic ability of neuronal dendrites to shape and integrate synaptic responses is the hallmark of information processing in the brain. Effectively studying this phenomenon requires concurrent measurements at multiple sites on live neurons. Significant progress has been made by optical imaging systems which combine confocal and multiphoton microscopy with inertia-free laser scanning. However, all systems developed to date restrict fast imaging to two dimensions. This severely limits the extent to which neurons can be studied, since they represent complex three-dimensional (3D) structures. Here we present a novel imaging system that utilizes a unique arrangement of acousto-optic deflectors to steer a focused ultra-fast laser beam to arbitrary locations in 3D space without moving the objective lens. As we demonstrate, this highly versatile random-access multiphoton microscope supports functional imaging of complex 3D cellular structures such as neuronal dendrites or neural populations at acquisition rates on the order of tens of kilohertz. PMID:18432198

An Advanced, Three-Dimensional Plotting Library for Astronomy

NASA Astrophysics Data System (ADS)

Barnes, David G.; Fluke, Christopher J.; Bourke, Paul D.; Parry, Owen T.

2006-07-01

We present a new, three-dimensional (3D) plotting library with advanced features, and support for standard and enhanced display devices. The library - s2plot - is written in c and can be used by c, c++, and fortran programs on GNU/Linux and Apple/OSX systems. s2plot draws objects in a 3D (x,y,z) Cartesian space and the user interactively controls how this space is rendered at run time. With a pgplot-inspired interface, s2plot provides astronomers with elegant techniques for displaying and exploring 3D data sets directly from their program code, and the potential to use stereoscopic and dome display devices. The s2plot architecture supports dynamic geometry and can be used to plot time-evolving data sets, such as might be produced by simulation codes. In this paper, we introduce s2plot to the astronomical community, describe its potential applications, and present some example uses of the library.

Two-component dark-bright solitons in three-dimensional atomic Bose-Einstein condensates.

PubMed

Wang, Wenlong; Kevrekidis, P G

2017-03-01

In the present work, we revisit two-component Bose-Einstein condensates in their fully three-dimensional (3D) form. Motivated by earlier studies of dark-bright solitons in the 1D case, we explore the stability of these structures in their fully 3D form in two variants. In one the dark soliton is planar and trapping a planar bright (disk) soliton. In the other case, a dark spherical shell soliton creates an effective potential in which a bright spherical shell of atoms is trapped in the second component. We identify these solutions as numerically exact states (up to a prescribed accuracy) and perform a Bogolyubov-de Gennes linearization analysis that illustrates that both structures can be dynamically stable in suitable intervals of sufficiently low chemical potentials. We corroborate this finding theoretically by analyzing the stability via degenerate perturbation theory near the linear limit of the system. When the solitary waves are found to be unstable, we explore their dynamical evolution via direct numerical simulations which, in turn, reveal wave forms that are more robust. Finally, using the SO(2) symmetry of the model, we produce multi-dark-bright planar or shell solitons involved in pairwise oscillatory motion.

Reduction of Thermal Conductivity by Nanoscale 3D Phononic Crystal

PubMed Central

Yang, Lina; Yang, Nuo; Li, Baowen

2013-01-01

We studied how the period length and the mass ratio affect the thermal conductivity of isotopic nanoscale three-dimensional (3D) phononic crystal of Si. Simulation results by equilibrium molecular dynamics show isotopic nanoscale 3D phononic crystals can significantly reduce the thermal conductivity of bulk Si at high temperature (1000 K), which leads to a larger ZT than unity. The thermal conductivity decreases as the period length and mass ratio increases. The phonon dispersion curves show an obvious decrease of group velocities in 3D phononic crystals. The phonon's localization and band gap is also clearly observed in spectra of normalized inverse participation ratio in nanoscale 3D phononic crystal. PMID:23378898

Quantification of collagen contraction in three-dimensional cell culture.

PubMed

Kopanska, Katarzyna S; Bussonnier, Matthias; Geraldo, Sara; Simon, Anthony; Vignjevic, Danijela; Betz, Timo

2015-01-01

Many different cell types including fibroblasts, smooth muscle cells, endothelial cells, and cancer cells exert traction forces on the fibrous components of the extracellular matrix. This can be observed as matrix contraction both macro- and microscopically in three-dimensional (3D) tissues models such as collagen type I gels. The quantification of local contraction at the micron scale, including its directionality and speed, in correlation with other parameters such as cell invasion, local protein or gene expression, can provide useful information to study wound healing, organism development, and cancer metastasis. In this article, we present a set of tools to quantify the flow dynamics of collagen contraction, induced by cells migrating out of a multicellular cancer spheroid into a three-dimensional (3D) collagen matrix. We adapted a pseudo-speckle technique that can be applied to bright-field and fluorescent microscopy time series. The image analysis presented here is based on an in-house written software developed in the Matlab (Mathworks) programming environment. The analysis program is freely available from GitHub following the link: http://dx.doi.org/10.5281/zenodo.10116. This tool provides an automatized technique to measure collagen contraction that can be utilized in different 3D cellular systems. Copyright © 2015 Elsevier Inc. All rights reserved.

A system of three-dimensional complex variables

NASA Technical Reports Server (NTRS)

Martin, E. Dale

1986-01-01

Some results of a new theory of multidimensional complex variables are reported, including analytic functions of a three-dimensional (3-D) complex variable. Three-dimensional complex numbers are defined, including vector properties and rules of multiplication. The necessary conditions for a function of a 3-D variable to be analytic are given and shown to be analogous to the 2-D Cauchy-Riemann equations. A simple example also demonstrates the analogy between the newly defined 3-D complex velocity and 3-D complex potential and the corresponding ordinary complex velocity and complex potential in two dimensions.

Digestive toxicities after palliative three-dimensional conformal radiation therapy (3D-CRT) for cervico-thoracic spinal metastases.

PubMed

Peyraga, Guillaume; Caron, Delphine; Lizee, Thibaut; Metayer, Yann; Septans, Anne-Lise; Pointreau, Yoann; Denis, Fabrice; Ganem, Gerard; Lafond, Cedrik; Roche, Sophie; Dupuis, Olivier

2018-06-01

The palliative treatment for cervico-thoracic spinal metastases is based on a three-dimensional conformal radiation therapy (3D-CRT). Digestive toxicities are common and cause a clinical impact frequently underestimated in patients. We performed a retrospective study of digestive side effects occurring after palliative 3D-CRT for cervico-thoracic spinal metastases. All patients receiving palliative 3D-CRT at Jean Bernard Center from January 2013 to December 2014 for spinal metastases between the 5th cervical vertebra (C5) and the 12th thoracic vertebra (T12) were eligible. Three-dimensional conformal RT was delivered by a linear accelerator (CLINAC, Varian). Premedication to prevent digestive toxicities was not used. Adverse events ("esophagitis" and "nausea and/or vomiting") were evaluated according to the NCI-CTCae (version 4). From January 2013 to December 2014, 128 patients met the study criteria. The median age was 68.6 years [31.8; 88.6]. Most patients (84.4%) received 30 Gy in 10 fractions. The median overall time of treatment was 13 days [3-33]. Forty patients (31.3%) suffered from grade ≥ 2 of "esophagitis" (35 grade 2 (27.4%) and 5 grade 3 (3.9%)). Eight patients (6.3%) suffered from grade ≥ 2 of "nausea and/or vomiting" (6 grade 2 (4.7%), 1 grade 3 (0.8%), and 1 grade 4 (0.8%)). The high incidence of moderate to severe digestive toxicities after palliative 3D-CRT for cervico-thoracic spinal metastases led to consider static or dynamic intensity-modulated radiation therapy (IMRT) to reduce the dose to organ at risk (the esophagus and stomach). Dosimetric studies and implementation in the clinic should be the next steps.

1-Dimensional AgVO3 nanowires hybrid with 2-dimensional graphene nanosheets to create 3-dimensional composite aerogels and their improved electrochemical properties

NASA Astrophysics Data System (ADS)

Liang, Liying; Xu, Yimeng; Lei, Yong; Liu, Haimei

2014-03-01

Three-dimensional (3D) porous composite aerogels have been synthesized via an innovative in situ hydrothermal method assisted by a freeze-drying process. In this hybrid structure, one-dimensional (1D) AgVO3 nanowires are uniformly dispersed on two-dimensional (2D) graphene nanosheet surfaces and/or are penetrated through the graphene sheets, forming 3D porous composite aerogels. As cathode materials for lithium-ion batteries, the composite aerogels exhibit high discharge capacity, excellent rate capability, and good cycling stability.Three-dimensional (3D) porous composite aerogels have been synthesized via an innovative in situ hydrothermal method assisted by a freeze-drying process. In this hybrid structure, one-dimensional (1D) AgVO3 nanowires are uniformly dispersed on two-dimensional (2D) graphene nanosheet surfaces and/or are penetrated through the graphene sheets, forming 3D porous composite aerogels. As cathode materials for lithium-ion batteries, the composite aerogels exhibit high discharge capacity, excellent rate capability, and good cycling stability. Electronic supplementary information (ESI) available: Preparation, characterization, SEM images, XRD patterns, and XPS of AgVO3/GAs. See DOI: 10.1039/c3nr06899d

TEMPEST: A computer code for three-dimensional analysis of transient fluid dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fort, J.A.

TEMPEST (Transient Energy Momentum and Pressure Equations Solutions in Three dimensions) is a powerful tool for solving engineering problems in nuclear energy, waste processing, chemical processing, and environmental restoration because it analyzes and illustrates 3-D time-dependent computational fluid dynamics and heat transfer analysis. It is a family of codes with two primary versions, a N- Version (available to public) and a T-Version (not currently available to public). This handout discusses its capabilities, applications, numerical algorithms, development status, and availability and assistance.

Dirac-, Rashba-, and Weyl-type spin-orbit couplings: Toward experimental realization in ultracold atoms

NASA Astrophysics Data System (ADS)

Wang, Bao-Zong; Lu, Yue-Hui; Sun, Wei; Chen, Shuai; Deng, Youjin; Liu, Xiong-Jun

2018-01-01

We propose a hierarchy set of minimal optical Raman lattice schemes to pave the way for experimental realization of high-dimensional spin-orbit (SO) couplings for ultracold atoms, including two-dimensional (2D) Dirac type, 2D Rashba type, and three-dimensional (3D) Weyl type. The proposed Dirac-type SO coupling exhibits precisely controllable high symmetry, for which a large topological phase region is predicted. The generation of 2D Rashba and 3D Weyl types requires that two sources of laser beams have distinct frequencies of factor 2 difference. Surprisingly, we find that 133Cs atoms provide an ideal candidate for the realization. A common and essential feature is of high controllability and absent of any fine-tuning in the realization, and the resulting SO coupled ultracold atoms have a long lifetime. In particular, a long-lived topological Bose gas of 2D Dirac SO coupling has been proved in the follow-up experiment. These schemes essentially improve over the current experimental accessibility and controllability, and open a realistic way to explore novel high-dimensional SO physics, particularly quantum many-body physics and quantum far-from-equilibrium dynamics with novel topology for ultracold atoms.

Three-dimensional chimera patterns in networks of spiking neuron oscillators

NASA Astrophysics Data System (ADS)

Kasimatis, T.; Hizanidis, J.; Provata, A.

2018-05-01

We study the stable spatiotemporal patterns that arise in a three-dimensional (3D) network of neuron oscillators, whose dynamics is described by the leaky integrate-and-fire (LIF) model. More specifically, we investigate the form of the chimera states induced by a 3D coupling matrix with nonlocal topology. The observed patterns are in many cases direct generalizations of the corresponding two-dimensional (2D) patterns, e.g., spheres, layers, and cylinder grids. We also find cylindrical and "cross-layered" chimeras that do not have an equivalent in 2D systems. Quantitative measures are calculated, such as the ratio of synchronized and unsynchronized neurons as a function of the coupling range, the mean phase velocities, and the distribution of neurons in mean phase velocities. Based on these measures, the chimeras are categorized in two families. The first family of patterns is observed for weaker coupling and exhibits higher mean phase velocities for the unsynchronized areas of the network. The opposite holds for the second family, where the unsynchronized areas have lower mean phase velocities. The various measures demonstrate discontinuities, indicating criticality as the parameters cross from the first family of patterns to the second.

Robust hypothesis tests for detecting statistical evidence of two-dimensional and three-dimensional interactions in single-molecule measurements

NASA Astrophysics Data System (ADS)

Calderon, Christopher P.; Weiss, Lucien E.; Moerner, W. E.

2014-05-01

Experimental advances have improved the two- (2D) and three-dimensional (3D) spatial resolution that can be extracted from in vivo single-molecule measurements. This enables researchers to quantitatively infer the magnitude and directionality of forces experienced by biomolecules in their native environment. Situations where such force information is relevant range from mitosis to directed transport of protein cargo along cytoskeletal structures. Models commonly applied to quantify single-molecule dynamics assume that effective forces and velocity in the x ,y (or x ,y,z) directions are statistically independent, but this assumption is physically unrealistic in many situations. We present a hypothesis testing approach capable of determining if there is evidence of statistical dependence between positional coordinates in experimentally measured trajectories; if the hypothesis of independence between spatial coordinates is rejected, then a new model accounting for 2D (3D) interactions can and should be considered. Our hypothesis testing technique is robust, meaning it can detect interactions, even if the noise statistics are not well captured by the model. The approach is demonstrated on control simulations and on experimental data (directed transport of intraflagellar transport protein 88 homolog in the primary cilium).

Turbulent mixing of a critical fluid: The non-perturbative renormalization

NASA Astrophysics Data System (ADS)

Hnatič, M.; Kalagov, G.; Nalimov, M.

2018-01-01

Non-perturbative Renormalization Group (NPRG) technique is applied to a stochastical model of a non-conserved scalar order parameter near its critical point, subject to turbulent advection. The compressible advecting flow is modeled by a random Gaussian velocity field with zero mean and correlation function 〈υjυi 〉 ∼ (Pji⊥ + αPji∥) /k d + ζ. Depending on the relations between the parameters ζ, α and the space dimensionality d, the model reveals several types of scaling regimes. Some of them are well known (model A of equilibrium critical dynamics and linear passive scalar field advected by a random turbulent flow), but there is a new nonequilibrium regime (universality class) associated with new nontrivial fixed points of the renormalization group equations. We have obtained the phase diagram (d, ζ) of possible scaling regimes in the system. The physical point d = 3, ζ = 4 / 3 corresponding to three-dimensional fully developed Kolmogorov's turbulence, where critical fluctuations are irrelevant, is stable for α ≲ 2.26. Otherwise, in the case of "strong compressibility" α ≳ 2.26, the critical fluctuations of the order parameter become relevant for three-dimensional turbulence. Estimations of critical exponents for each scaling regime are presented.

3D structural fluctuation of IgG1 antibody revealed by individual particle electron tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xing; Zhang, Lei; Tong, Huimin

2015-05-05

Commonly used methods for determining protein structure, including X-ray crystallography and single-particle reconstruction, often provide a single and unique three-dimensional (3D) structure. However, in these methods, the protein dynamics and flexibility/fluctuation remain mostly unknown. Here, we utilized advances in electron tomography (ET) to study the antibody flexibility and fluctuation through structural determination of individual antibody particles rather than averaging multiple antibody particles together. Through individual-particle electron tomography (IPET) 3D reconstruction from negatively-stained ET images, we obtained 120 ab-initio 3D density maps at an intermediate resolution (~1–3 nm) from 120 individual IgG1 antibody particles. Using these maps as a constraint, wemore » derived 120 conformations of the antibody via structural flexible docking of the crystal structure to these maps by targeted molecular dynamics simulations. Statistical analysis of the various conformations disclosed the antibody 3D conformational flexibility through the distribution of its domain distances and orientations. This blueprint approach, if extended to other flexible proteins, may serve as a useful methodology towards understanding protein dynamics and functions.« less

Time-dependent optical response of three-dimensional Au nanoparticle arrays formed on silica nanowires

NASA Astrophysics Data System (ADS)

Di Mario, Lorenzo; Otomalo, Tadele Orbula; Catone, Daniele; O'Keeffe, Patrick; Tian, Lin; Turchini, Stefano; Palpant, Bruno; Martelli, Faustino

2018-03-01

We present stationary and transient absorption measurements on 3D Au nanoparticle (NP)-decorated Si O2 nanowire arrays. The 3D NP array has been produced by the dewetting of a thin Au film deposited on silica nanowires produced by oxidation of silicon nanowires. The experimental behaviors of the spectral and temporal dynamics observed in the experiment are accurately described by a two-step, three-temperature model. Using an arbitrary set of Au NPs with different aspect ratios, we demonstrate that the width of the experimental spectra, the energy shift of their position with time, and the asymmetry between the two positive wings in the dynamical variation of absorption can all be attributed to the nonuniform shape distribution of the Au NPs in the sample.

Modeling dynamic stall on wind turbine blades under rotationally augmented flow fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guntur, S.; Schreck, S.; Sorensen, N. N.

It is well known that airfoils under unsteady flow conditions with a periodically varying angle of attack exhibit aerodynamic characteristics different from those under steady flow conditions, a phenomenon commonly known as dynamic stall. It is also well known that the steady aerodynamic characteristics of airfoils in the inboard region of a rotating blade differ from those under steady two-dimensional (2D) flow conditions, a phenomenon commonly known as rotational augmentation. This paper presents an investigation of these two phenomena together in the inboard parts of wind turbine blades. This analysis is carried out using data from three sources: (1) themore » National Renewable Energy Laboratory’s Unsteady Aerodynamics Experiment Phase VI experimental data, including constant as well as continuously pitching blade conditions during axial operation, (2) data from unsteady Delayed Detached Eddy Simulations (DDES) carried out using the Technical University of Denmark’s in-house flow solver Ellipsys3D, and (3) data from a simplified model based on the blade element momentum method with a dynamic stall subroutine that uses rotationally augmented steady-state polars obtained from steady Phase VI experimental sequences, instead of the traditional 2D nonrotating data. The aim of this work is twofold. First, the blade loads estimated by the DDES simulations are compared to three select cases of the N sequence experimental data, which serves as a validation of the DDES method. Results show reasonable agreement between the two data in two out of three cases studied. Second, the dynamic time series of the lift and the moment polars obtained from the experiments are compared to those from the dynamic stall subroutine that uses the rotationally augmented steady polars. This allowed the differences between the stall phenomenon on the inboard parts of harmonically pitching blades on a rotating wind turbine and the classic dynamic stall representation in 2D flow to be investigated. Results from the dynamic stall subroutine indicated a good qualitative agreement between the model and the experimental data in many cases, which suggests that the current 2D dynamic stall model as used in BEM-based aeroelastic codes may provide a reasonably accurate representation of three-dimensional rotor aerodynamics when used in combination with a robust rotational augmentation model.« less

Dynamical Localization for Discrete Anderson Dirac Operators

NASA Astrophysics Data System (ADS)

Prado, Roberto A.; de Oliveira, César R.; Carvalho, Silas L.

2017-04-01

We establish dynamical localization for random Dirac operators on the d-dimensional lattice, with d\\in { 1, 2, 3} , in the three usual regimes: large disorder, band edge and 1D. These operators are discrete versions of the continuous Dirac operators and consist in the sum of a discrete free Dirac operator with a random potential. The potential is a diagonal matrix formed by different scalar potentials, which are sequences of independent and identically distributed random variables according to an absolutely continuous probability measure with bounded density and of compact support. We prove the exponential decay of fractional moments of the Green function for such models in each of the above regimes, i.e., (j) throughout the spectrum at larger disorder, (jj) for energies near the band edges at arbitrary disorder and (jjj) in dimension one, for all energies in the spectrum and arbitrary disorder. Dynamical localization in theses regimes follows from the fractional moments method. The result in the one-dimensional regime contrast with one that was previously obtained for 1D Dirac model with Bernoulli potential.

Feedback-Based, System-Level Properties of Vertebrate-Microbial Interactions

PubMed Central

Rivas, Ariel L.; Jankowski, Mark D.; Piccinini, Renata; Leitner, Gabriel; Schwarz, Daniel; Anderson, Kevin L.; Fair, Jeanne M.; Hoogesteijn, Almira L.; Wolter, Wilfried; Chaffer, Marcelo; Blum, Shlomo; Were, Tom; Konah, Stephen N.; Kempaiah, Prakash; Ong’echa, John M.; Diesterbeck, Ulrike S.; Pilla, Rachel; Czerny, Claus-Peter; Hittner, James B.; Hyman, James M.; Perkins, Douglas J.

2013-01-01

Background Improved characterization of infectious disease dynamics is required. To that end, three-dimensional (3D) data analysis of feedback-like processes may be considered. Methods To detect infectious disease data patterns, a systems biology (SB) and evolutionary biology (EB) approach was evaluated, which utilizes leukocyte data structures designed to diminish data variability and enhance discrimination. Using data collected from one avian and two mammalian (human and bovine) species infected with viral, parasite, or bacterial agents (both sensitive and resistant to antimicrobials), four data structures were explored: (i) counts or percentages of a single leukocyte type, such as lymphocytes, neutrophils, or macrophages (the classic approach), and three levels of the SB/EB approach, which assessed (ii) 2D, (iii) 3D, and (iv) multi-dimensional (rotating 3D) host-microbial interactions. Results In all studies, no classic data structure discriminated disease-positive (D+, or observations in which a microbe was isolated) from disease-negative (D–, or microbial-negative) groups: D+ and D– data distributions overlapped. In contrast, multi-dimensional analysis of indicators designed to possess desirable features, such as a single line of observations, displayed a continuous, circular data structure, whose abrupt inflections facilitated partitioning into subsets statistically significantly different from one another. In all studies, the 3D, SB/EB approach distinguished three (steady, positive, and negative) feedback phases, in which D– data characterized the steady state phase, and D+ data were found in the positive and negative phases. In humans, spatial patterns revealed false-negative observations and three malaria-positive data classes. In both humans and bovines, methicillin-resistant Staphylococcus aureus (MRSA) infections were discriminated from non-MRSA infections. Conclusions More information can be extracted, from the same data, provided that data are structured, their 3D relationships are considered, and well-conserved (feedback-like) functions are estimated. Patterns emerging from such structures may distinguish well-conserved from recently developed host-microbial interactions. Applications include diagnosis, error detection, and modeling. PMID:23437039

Digital stereo-holographic microscopy for studying three-dimensional particle dynamics

NASA Astrophysics Data System (ADS)

Byeon, Hyeokjun; Go, Taesik; Lee, Sang Joon

2018-06-01

A digital stereo-holographic microscopy (DsHM) with two viewing angles is proposed to measure 3D information of microscale particles. This approach includes two volumetric recordings and numerical reconstruction, and it involves the combination of separately reconstructed holograms. The 3D positional information of a particle was determined by searching the center of the overlapped reconstructed volume. After confirming the proposed technique using static spherical particles, the 3D information of moving particles suspended in a Hagen-Poiseiulle flow was successfully obtained. Moreover, the 3D information of nonspherical particles, including ellipsoidal particles and red blood cells, were measured using the proposed technique. In addition to 3D positional information, the orientation and shape of the test samples were obtained from the plane images by slicing the overlapped volume perpendicular to the directions of the image recordings. This DsHM technique will be useful in analyzing the 3D dynamic behavior of various nonspherical particles, which cannot be measured by conventional digital holographic microscopy.

Three-dimensional imaging technology offers promise in medicine.

PubMed

Karako, Kenji; Wu, Qiong; Gao, Jianjun

2014-04-01

Medical imaging plays an increasingly important role in the diagnosis and treatment of disease. Currently, medical equipment mainly has two-dimensional (2D) imaging systems. Although this conventional imaging largely satisfies clinical requirements, it cannot depict pathologic changes in 3 dimensions. The development of three-dimensional (3D) imaging technology has encouraged advances in medical imaging. Three-dimensional imaging technology offers doctors much more information on a pathology than 2D imaging, thus significantly improving diagnostic capability and the quality of treatment. Moreover, the combination of 3D imaging with augmented reality significantly improves surgical navigation process. The advantages of 3D imaging technology have made it an important component of technological progress in the field of medical imaging.

Simultaneous Detection of Static and Dynamic Signals by a Flexible Sensor Based on 3D Graphene.

PubMed

Xu, Rongqing; Wang, Di; Zhang, Hongchao; Xie, Na; Lu, Shan; Qu, Ke

2017-05-08

A flexible acoustic pressure sensor was developed based on the change in electrical resistance of three-dimensional (3D) graphene change under the acoustic waves action. The sensor was constructed by 3D graphene foam (GF) wrapped in flexible polydimethylsiloxane (PDMS). Tuning forks and human physiological tests indicated that the acoustic pressure sensor can sensitively detect the deformation and the acoustic pressure in real time. The results are of significance to the development of graphene-based applications in the field of health monitoring, in vitro diagnostics, advanced therapies, and transient pressure detection.

System and Method for Measuring Skin Movement and Strain and Related Techniques

NASA Technical Reports Server (NTRS)

Newman, Dava J. (Inventor); Wessendorf, Ashley M. (Inventor)

2015-01-01

Described herein are systems and techniques for a motion capture system and a three-dimensional (3D) tracking system used to record body position and/or movements/motions and using the data to measure skin strain (a strain field) all along the body while a joint is in motion (dynamic) as well as in a fixed position (static). The data and technique can be used to quantify strains, calculate 3D contours, and derive patterns believed to reveal skin's properties during natural motions.

Fast interactive real-time volume rendering of real-time three-dimensional echocardiography: an implementation for low-end computers

NASA Technical Reports Server (NTRS)

Saracino, G.; Greenberg, N. L.; Shiota, T.; Corsi, C.; Lamberti, C.; Thomas, J. D.

2002-01-01

Real-time three-dimensional echocardiography (RT3DE) is an innovative cardiac imaging modality. However, partly due to lack of user-friendly software, RT3DE has not been widely accepted as a clinical tool. The object of this study was to develop and implement a fast and interactive volume renderer of RT3DE datasets designed for a clinical environment where speed and simplicity are not secondary to accuracy. Thirty-six patients (20 regurgitation, 8 normal, 8 cardiomyopathy) were imaged using RT3DE. Using our newly developed software, all 3D data sets were rendered in real-time throughout the cardiac cycle and assessment of cardiac function and pathology was performed for each case. The real-time interactive volume visualization system is user friendly and instantly provides consistent and reliable 3D images without expensive workstations or dedicated hardware. We believe that this novel tool can be used clinically for dynamic visualization of cardiac anatomy.

Insights into the three-dimensional Lagrangian geometry of the Antarctic polar vortex

NASA Astrophysics Data System (ADS)

Curbelo, Jezabel; José García-Garrido, Víctor; Mechoso, Carlos Roberto; Mancho, Ana Maria; Wiggins, Stephen; Niang, Coumba

2017-07-01

In this paper we study the three-dimensional (3-D) Lagrangian structures in the stratospheric polar vortex (SPV) above Antarctica. We analyse and visualize these structures using Lagrangian descriptor function M. The procedure for calculation with reanalysis data is explained. Benchmarks are computed and analysed that allow us to compare 2-D and 3-D aspects of Lagrangian transport. Dynamical systems concepts appropriate to 3-D, such as normally hyperbolic invariant curves, are discussed and applied. In order to illustrate our approach we select an interval of time in which the SPV is relatively undisturbed (August 1979) and an interval of rapid SPV changes (October 1979). Our results provide new insights into the Lagrangian structure of the vertical extension of the stratospheric polar vortex and its evolution. Our results also show complex Lagrangian patterns indicative of strong mixing processes in the upper troposphere and lower stratosphere. Finally, during the transition to summer in the late spring, we illustrate the vertical structure of two counterrotating vortices, one the polar and the other an emerging one, and the invariant separatrix that divides them.

Performance of a reduced-order FSI model for flow-induced vocal fold vibration

NASA Astrophysics Data System (ADS)

Chang, Siyuan; Luo, Haoxiang; Luo's lab Team

2016-11-01

Vocal fold vibration during speech production involves a three-dimensional unsteady glottal jet flow and three-dimensional nonlinear tissue mechanics. A full 3D fluid-structure interaction (FSI) model is computationally expensive even though it provides most accurate information about the system. On the other hand, an efficient reduced-order FSI model is useful for fast simulation and analysis of the vocal fold dynamics, which is often needed in procedures such as optimization and parameter estimation. In this work, we study the performance of a reduced-order model as compared with the corresponding full 3D model in terms of its accuracy in predicting the vibration frequency and deformation mode. In the reduced-order model, we use a 1D flow model coupled with a 3D tissue model. Two different hyperelastic tissue behaviors are assumed. In addition, the vocal fold thickness and subglottal pressure are varied for systematic comparison. The result shows that the reduced-order model provides consistent predictions as the full 3D model across different tissue material assumptions and subglottal pressures. However, the vocal fold thickness has most effect on the model accuracy, especially when the vocal fold is thin. Supported by the NSF.

Comparison of quasi-static and dynamic squats: a three-dimensional kinematic, kinetic and electromyographic study of the lower limbs.

PubMed

Clément, Julien; Hagemeister, Nicola; Aissaoui, Rachid; de Guise, Jacques A

2014-01-01

Numerous studies have described 3D kinematics, 3D kinetics and electromyography (EMG) of the lower limbs during quasi-static or dynamic squatting activities. One study compared these two squatting conditions but only at low speed on healthy subjects, and provided no information on kinetics and EMG of the lower limbs. The purpose of the present study was to contrast simultaneous recordings of 3D kinematics, 3D kinetics and EMG of the lower limbs during quasi-stat ic and fast-dynamic squats in healthy and pathological subjects. Ten subjects were recruited: five healthy and five osteoarthritis subjects. A motion-capture system, force plate, and surface electrodes respectively recorded 3D kinematics, 3D kinetics and EMG of the lower limbs. Each subject performed a quasi-static squat and several fast-dynamic squats from 0° to 70° of knee flexion. The two squatting conditions were compared for positions where quasi-static and fast-dynamic knee flexion-extension angles were similar. Mean differences between quasi-static and fast-dynamic squats were 1.5° for rotations, 1.9 mm for translations, 2.1% of subjects' body weight for ground reaction forces, 6.6 Nm for torques, 11.2 mm for center of pressure, and 6.3% of maximum fast-dynamic electromyographic activities for EMG. Some significant differences (p<0.05) were found in internal rotation, anterior translation, vertical force and EMG. All differences between quasi-static and fast-dynamic squats were small. 69.5% of compared data were equivalent. In conclusion, this study showed that quasi-static and fast-dynamic squatting activities are comparable in terms of 3D kinematics, 3D kinetics and EMG, although some reservations still remain. Copyright © 2014 Elsevier B.V. All rights reserved.

Single calibration multiplane stereo-PIV: the effect of mitral valve orientation on three-dimensional flow in a left ventricle model

NASA Astrophysics Data System (ADS)

Saaid, Hicham; Segers, Patrick; Novara, Matteo; Claessens, Tom; Verdonck, Pascal

2018-03-01

The characterization of flow patterns in the left ventricle may help the development and interpretation of flow-based parameters of cardiac function and (patho-)physiology. Yet, in vivo visualization of highly dynamic three-dimensional flow patterns in an opaque and moving chamber is a challenging task. This has been shown in several recent multidisciplinary studies where in vivo imaging methods are often complemented by in silico solutions, or by in vitro methods. Because of its distinctive features, particle image velocimetry (PIV) has been extensively used to investigate flow dynamics in the cardiovascular field. However, full volumetric PIV data in a dynamically changing geometry such as the left ventricle remain extremely scarce, which justifies the present study. An investigation of the left ventricle flow making use of a customized cardiovascular simulator is presented; a multiplane scanning-stereoscopic PIV setup is used, which allows for the measurement of independent planes across the measurement volume. Due to the accuracy in traversing the illumination and imaging systems, the present setup allows to reconstruct the flow in a 3D volume performing only one single calibration. The effects of the orientation of a prosthetic mitral valve in anatomical and anti-anatomical configurations have been investigated during the diastolic filling time. The measurement is performed in a phase-locked manner; the mean velocity components are presented together with the vorticity and turbulent kinetic energy maps. The reconstructed 3D flow structures downstream the bileaflet mitral valve are shown, which provides additional insight of the highly three-dimensional flow.

Interfacing 3D Engineered Neuronal Cultures to Micro-Electrode Arrays: An Innovative In Vitro Experimental Model.

PubMed

Tedesco, Mariateresa; Frega, Monica; Martinoia, Sergio; Pesce, Mattia; Massobrio, Paolo

2015-10-18

Currently, large-scale networks derived from dissociated neurons growing and developing in vitro on extracellular micro-transducer devices are the gold-standard experimental model to study basic neurophysiological mechanisms involved in the formation and maintenance of neuronal cell assemblies. However, in vitro studies have been limited to the recording of the electrophysiological activity generated by bi-dimensional (2D) neural networks. Nonetheless, given the intricate relationship between structure and dynamics, a significant improvement is necessary to investigate the formation and the developing dynamics of three-dimensional (3D) networks. In this work, a novel experimental platform in which 3D hippocampal or cortical networks are coupled to planar Micro-Electrode Arrays (MEAs) is presented. 3D networks are realized by seeding neurons in a scaffold constituted of glass microbeads (30-40 µm in diameter) on which neurons are able to grow and form complex interconnected 3D assemblies. In this way, it is possible to design engineered 3D networks made up of 5-8 layers with an expected final cell density. The increasing complexity in the morphological organization of the 3D assembly induces an enhancement of the electrophysiological patterns displayed by this type of networks. Compared with the standard 2D networks, where highly stereotyped bursting activity emerges, the 3D structure alters the bursting activity in terms of duration and frequency, as well as it allows observation of more random spiking activity. In this sense, the developed 3D model more closely resembles in vivo neural networks.

Interfacing 3D Engineered Neuronal Cultures to Micro-Electrode Arrays: An Innovative In Vitro Experimental Model

PubMed Central

Tedesco, Mariateresa; Frega, Monica; Martinoia, Sergio; Pesce, Mattia; Massobrio, Paolo

2015-01-01

Currently, large-scale networks derived from dissociated neurons growing and developing in vitro on extracellular micro-transducer devices are the gold-standard experimental model to study basic neurophysiological mechanisms involved in the formation and maintenance of neuronal cell assemblies. However, in vitro studies have been limited to the recording of the electrophysiological activity generated by bi-dimensional (2D) neural networks. Nonetheless, given the intricate relationship between structure and dynamics, a significant improvement is necessary to investigate the formation and the developing dynamics of three-dimensional (3D) networks. In this work, a novel experimental platform in which 3D hippocampal or cortical networks are coupled to planar Micro-Electrode Arrays (MEAs) is presented. 3D networks are realized by seeding neurons in a scaffold constituted of glass microbeads (30-40 µm in diameter) on which neurons are able to grow and form complex interconnected 3D assemblies. In this way, it is possible to design engineered 3D networks made up of 5-8 layers with an expected final cell density. The increasing complexity in the morphological organization of the 3D assembly induces an enhancement of the electrophysiological patterns displayed by this type of networks. Compared with the standard 2D networks, where highly stereotyped bursting activity emerges, the 3D structure alters the bursting activity in terms of duration and frequency, as well as it allows observation of more random spiking activity. In this sense, the developed 3D model more closely resembles in vivo neural networks. PMID:26554533

Three-Dimensional Printing of pH-Responsive and Functional Polymers on an Affordable Desktop Printer.

PubMed

Nadgorny, Milena; Xiao, Zeyun; Chen, Chao; Connal, Luke A

2016-10-26

In this work we describe the synthesis, thermal and rheological characterization, hot-melt extrusion, and three-dimensional printing (3DP) of poly(2-vinylpyridine) (P2VP). We investigate the effect of thermal processing conditions on physical properties of produced filaments in order to achieve high quality, 3D-printable filaments for material extrusion 3DP (ME3DP). Mechanical properties and processing performances of P2VP were enhanced by addition of 12 wt % acrylonitrile-butadiene-styrene (ABS), which reinforced P2VP fibers. We 3D-print P2VP filaments using an affordable 3D printer. The pyridine moieties are cross-linked and quaternized postprinting to form 3D-printed pH-responsive hydrogels. The printed objects exhibited dynamic and reversible pH-dependent swelling. These hydrogels act as flow-regulating valves, controlling the flow rate with pH. Additionally, a macroporous P2VP membrane was 3D-printed and the coordinating ability of the pyridyl groups was employed to immobilize silver precursors on its surface. After the reduction of silver ions, the structure was used to catalyze the reduction of 4-nitrophenol to 4-aminophenol with a high efficiency. This is a facile technique to print recyclable catalytic objects.

A study to evaluate the reliability of using two-dimensional photographs, three-dimensional images, and stereoscopic projected three-dimensional images for patient assessment.

PubMed

Zhu, S; Yang, Y; Khambay, B

2017-03-01

Clinicians are accustomed to viewing conventional two-dimensional (2D) photographs and assume that viewing three-dimensional (3D) images is similar. Facial images captured in 3D are not viewed in true 3D; this may alter clinical judgement. The aim of this study was to evaluate the reliability of using conventional photographs, 3D images, and stereoscopic projected 3D images to rate the severity of the deformity in pre-surgical class III patients. Forty adult patients were recruited. Eight raters assessed facial height, symmetry, and profile using the three different viewing media and a 100-mm visual analogue scale (VAS), and appraised the most informative viewing medium. Inter-rater consistency was above good for all three media. Intra-rater reliability was not significantly different for rating facial height using 2D (P=0.704), symmetry using 3D (P=0.056), and profile using projected 3D (P=0.749). Using projected 3D for rating profile and symmetry resulted in significantly lower median VAS scores than either 3D or 2D images (all P<0.05). For 75% of the raters, stereoscopic 3D projection was the preferred method for rating. The reliability of assessing specific characteristics was dependent on the viewing medium. Clinicians should be aware that the visual information provided when viewing 3D images is not the same as when viewing 2D photographs, especially for facial depth, and this may change the clinical impression. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

On the Rigorous Derivation of the 3D Cubic Nonlinear Schrödinger Equation with a Quadratic Trap

NASA Astrophysics Data System (ADS)

Chen, Xuwen

2013-11-01

We consider the dynamics of the three-dimensional N-body Schrödinger equation in the presence of a quadratic trap. We assume the pair interaction potential is N 3 β-1 V( N β x). We justify the mean-field approximation and offer a rigorous derivation of the three-dimensional cubic nonlinear Schrödinger equation (NLS) with a quadratic trap. We establish the space-time bound conjectured by Klainerman and Machedon (Commun Math Phys 279:169-185, 2008) for by adapting and simplifying an argument in Chen and Pavlović (Annales Henri Poincaré, 2013) which solves the problem for in the absence of a trap.

Laser irradiated fluorescent perfluorocarbon microparticles in 2-D and 3-D breast cancer cell models

NASA Astrophysics Data System (ADS)

Niu, Chengcheng; Wang, Long; Wang, Zhigang; Xu, Yan; Hu, Yihe; Peng, Qinghai

2017-03-01

Perfluorocarbon (PFC) droplets were studied as new generation ultrasound contrast agents via acoustic or optical droplet vaporization (ADV or ODV). Little is known about the ODV irradiated vaporization mechanisms of PFC-microparticle complexs and the stability of the new bubbles produced. In this study, fluorescent perfluorohexane (PFH) poly(lactic-co-glycolic acid) (PLGA) particles were used as a model to study the process of particle vaporization and bubble stability following excitation in two-dimensional (2-D) and three-dimensional (3-D) cell models. We observed localization of the fluorescent agent on the microparticle coating material initially and after vaporization under fluorescence microscopy. Furthermore, the stability and growth dynamics of the newly created bubbles were observed for 11 min following vaporization. The particles were co-cultured with 2-D cells to form 3-D spheroids and could be vaporized even when encapsulated within the spheroids via laser irradiation, which provides an effective basis for further work.

A comparative study of Rayleigh-Taylor and Richtmyer-Meshkov instabilities in 2D and 3D in tantalum

NASA Astrophysics Data System (ADS)

Sternberger, Z.; Maddox, B. R.; Opachich, Y. P.; Wehrenberg, C. E.; Kraus, R. G.; Remington, B. A.; Randall, G. C.; Farrell, M.; Ravichandran, G.

2017-01-01

Driving a shock wave through the interface between two materials with different densities can result in the Richtmyer-Meshkov or Rayleigh-Taylor instability and initial perturbations at the interface will grow. If the shock wave is sufficiently strong, the instability will lead to plastic flow at the interface. Material strength will reduce the amount of plastic flow and suppress growth. While such instabilities have been investigated in 2D, no studies of this phenomena have been performed in 3D on materials with strength. Initial perturbations to seed the hydrodynamic instability were coined into tantalum recovery targets. Two types of perturbations were used, two dimensional (2D) perturbations (hill and valley) and three-dimensional (3D) perturbations (egg crate pattern). The targets were subjected to dynamic loading using the Janus laser at the Jupiter Laser Facility. Shock pressures ranged from 50 GPa up to 150 GPa and were calibrated using VISAR drive targets.

Assessment of Preconditioner for a USM3D Hierarchical Adaptive Nonlinear Method (HANIM) (Invited)

NASA Technical Reports Server (NTRS)

Pandya, Mohagna J.; Diskin, Boris; Thomas, James L.; Frink, Neal T.

2016-01-01

Enhancements to the previously reported mixed-element USM3D Hierarchical Adaptive Nonlinear Iteration Method (HANIM) framework have been made to further improve robustness, efficiency, and accuracy of computational fluid dynamic simulations. The key enhancements include a multi-color line-implicit preconditioner, a discretely consistent symmetry boundary condition, and a line-mapping method for the turbulence source term discretization. The USM3D iterative convergence for the turbulent flows is assessed on four configurations. The configurations include a two-dimensional (2D) bump-in-channel, the 2D NACA 0012 airfoil, a three-dimensional (3D) bump-in-channel, and a 3D hemisphere cylinder. The Reynolds Averaged Navier Stokes (RANS) solutions have been obtained using a Spalart-Allmaras turbulence model and families of uniformly refined nested grids. Two types of HANIM solutions using line- and point-implicit preconditioners have been computed. Additional solutions using the point-implicit preconditioner alone (PA) method that broadly represents the baseline solver technology have also been computed. The line-implicit HANIM shows superior iterative convergence in most cases with progressively increasing benefits on finer grids.

Rewritable three-dimensional holographic data storage via optical forces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yetisen, Ali K., E-mail: ayetisen@mgh.harvard.edu; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; Montelongo, Yunuen

2016-08-08

The development of nanostructures that can be reversibly arranged and assembled into 3D patterns may enable optical tunability. However, current dynamic recording materials such as photorefractive polymers cannot be used to store information permanently while also retaining configurability. Here, we describe the synthesis and optimization of a silver nanoparticle doped poly(2-hydroxyethyl methacrylate-co-methacrylic acid) recording medium for reversibly recording 3D holograms. We theoretically and experimentally demonstrate organizing nanoparticles into 3D assemblies in the recording medium using optical forces produced by the gradients of standing waves. The nanoparticles in the recording medium are organized by multiple nanosecond laser pulses to produce reconfigurablemore » slanted multilayer structures. We demonstrate the capability of producing rewritable optical elements such as multilayer Bragg diffraction gratings, 1D photonic crystals, and 3D multiplexed optical gratings. We also show that 3D virtual holograms can be reversibly recorded. This recording strategy may have applications in reconfigurable optical elements, data storage devices, and dynamic holographic displays.« less

Effect of dynamic three-dimensional culture on osteogenic potential of human periodontal ligament-derived mesenchymal stem cells entrapped in alginate microbeads.

PubMed

Vecchiatini, R; Penolazzi, L; Lambertini, E; Angelozzi, M; Morganti, C; Mazzitelli, S; Trombelli, L; Nastruzzi, C; Piva, R

2015-08-01

Bioreactors are devices that efficiently create an environment that enables cell cultures to grow in a three-dimensional (3D) context mimicking in vivo conditions. In this study, we investigate the effect of dynamic fluid flow on the osteogenic potential of human mesenchymal stem cells obtained from periodontal ligament and entrapped in alginate microbeads. After proper immunophenotyping, cells were encapsulated in barium alginate, cultured in 3D static or 3D dynamic conditions represented by a bioreactor system. Calcein-AM/propidium iodide staining was used to assess cellular viability. Quantitative real-time polymerase chain reaction was used to analyze the expression of osteogenic markers (Runx2 and COL1). Alizarin Red S staining and the Fourier transform infrared spectroscopy were used to assess mineral matrix deposition. Optimal encapsulation procedure, in terms of polymer pumping rate, distance from droplet generator to the gelling bath and atomizing airflow was assessed. Cell viability was not affected by encapsulation in alginate microbeads. Bioreactor cell exposure was effective in anticipating osteogenic differentiation and improving mineral matrix deposition. For the first time human mesenchymal stem cells obtained from periodontal ligaments encapsulated in alginate microbeads were cultured in a bioreactor system. This combination could represent a promising strategy to create a cell-based smart system with enhanced osteogenic potential useful for many different dental applications. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Performance of a reduced-order FSI model for flow-induced vocal fold vibration

NASA Astrophysics Data System (ADS)

Luo, Haoxiang; Chang, Siyuan; Chen, Ye; Rousseau, Bernard; PhonoSim Team

2017-11-01

Vocal fold vibration during speech production involves a three-dimensional unsteady glottal jet flow and three-dimensional nonlinear tissue mechanics. A full 3D fluid-structure interaction (FSI) model is computationally expensive even though it provides most accurate information about the system. On the other hand, an efficient reduced-order FSI model is useful for fast simulation and analysis of the vocal fold dynamics, which can be applied in procedures such as optimization and parameter estimation. In this work, we study performance of a reduced-order model as compared with the corresponding full 3D model in terms of its accuracy in predicting the vibration frequency and deformation mode. In the reduced-order model, we use a 1D flow model coupled with a 3D tissue model that is the same as in the full 3D model. Two different hyperelastic tissue behaviors are assumed. In addition, the vocal fold thickness and subglottal pressure are varied for systematic comparison. The result shows that the reduced-order model provides consistent predictions as the full 3D model across different tissue material assumptions and subglottal pressures. However, the vocal fold thickness has most effect on the model accuracy, especially when the vocal fold is thin.

Three-dimensional photography for the evaluation of facial profiles in obstructive sleep apnoea.

PubMed

Lin, Shih-Wei; Sutherland, Kate; Liao, Yu-Fang; Cistulli, Peter A; Chuang, Li-Pang; Chou, Yu-Ting; Chang, Chih-Hao; Lee, Chung-Shu; Li, Li-Fu; Chen, Ning-Hung

2018-06-01

Craniofacial structure is an important determinant of obstructive sleep apnoea (OSA) syndrome risk. Three-dimensional stereo-photogrammetry (3dMD) is a novel technique which allows quantification of the craniofacial profile. This study compares the facial images of OSA patients captured by 3dMD to three-dimensional computed tomography (3-D CT) and two-dimensional (2-D) digital photogrammetry. Measurements were correlated with indices of OSA severity. Thirty-eight patients diagnosed with OSA were included, and digital photogrammetry, 3dMD and 3-D CT were performed. Distances, areas, angles and volumes from the images captured by three methods were analysed. Almost all measurements captured by 3dMD showed strong agreement with 3-D CT measurements. Results from 2-D digital photogrammetry showed poor agreement with 3-D CT. Mandibular width, neck perimeter size and maxillary volume measurements correlated well with the severity of OSA using all three imaging methods. Mandibular length, facial width, binocular width, neck width, cranial base triangle area, cranial base area 1 and middle cranial fossa volume correlated well with OSA severity using 3dMD and 3-D CT, but not with 2-D digital photogrammetry. 3dMD provided accurate craniofacial measurements of OSA patients, which were highly concordant with those obtained by CT, while avoiding the radiation associated with CT. © 2018 Asian Pacific Society of Respirology.

Three-dimensional color Doppler echocardiographic quantification of tricuspid regurgitation orifice area: comparison with conventional two-dimensional measures.

PubMed

Chen, Tien-En; Kwon, Susan H; Enriquez-Sarano, Maurice; Wong, Benjamin F; Mankad, Sunil V

2013-10-01

Three-dimensional (3D) color Doppler echocardiography (CDE) provides directly measured vena contracta area (VCA). However, a large comprehensive 3D color Doppler echocardiographic study with sufficiently severe tricuspid regurgitation (TR) to verify its value in determining TR severity in comparison with conventional quantitative and semiquantitative two-dimensional (2D) parameters has not been previously conducted. The aim of this study was to examine the utility and feasibility of directly measured VCA by 3D transthoracic CDE, its correlation with 2D echocardiographic measurements of TR, and its ability to determine severe TR. Ninety-two patients with mild or greater TR prospectively underwent 2D and 3D transthoracic echocardiography. Two-dimensional evaluation of TR severity included the ratio of jet area to right atrial area, vena contracta width, and quantification of effective regurgitant orifice area using the flow convergence method. Full-volume breath-hold 3D color data sets of TR were obtained using a real-time 3D echocardiography system. VCA was directly measured by 3D-guided direct planimetry of the color jet. Subgroup analysis included the presence of a pacemaker, eccentricity of the TR jet, ellipticity of the orifice shape, underlying TR mechanism, and baseline rhythm. Three-dimensional VCA correlated well with effective regurgitant orifice area (r = 0.62, P < .0001), moderately with vena contracta width (r = 0.42, P < .0001), and weakly with jet area/right atrial area ratio. Subgroup analysis comparing 3D VCA with 2D effective regurgitant orifice area demonstrated excellent correlation for organic TR (r = 0.86, P < .0001), regular rhythm (r = 0.78, P < .0001), and circular orifice (r = 0.72, P < .0001) but poor correlation in atrial fibrillation rhythm (r = 0.23, P = .0033). Receiver operating characteristic curve analysis for 3D VCA demonstrated good accuracy for severe TR determination. Three-dimensional VCA measurement is feasible and obtainable in the majority of patients with mild or greater TR. Three-dimensional VCA measurement is also feasible in patients with atrial fibrillation but performed poorly even with <20% cycle length variation. Three-dimensional VCA has good cutoff accuracy in determining severe TR. This simple, straightforward 3D color Doppler measurement shows promise as an alternative for the quantification of TR. Copyright © 2013 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

Three-dimensional single-mode nonlinear ablative Rayleigh-Taylor instability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, R.; Aluie, H.; Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14627

The nonlinear evolution of the single-mode ablative Rayleigh-Taylor instability is studied in three dimensions. As the mode wavelength approaches the cutoff of the linear spectrum (short-wavelength modes), it is found that the three-dimensional (3D) terminal bubble velocity greatly exceeds both the two-dimensional (2D) value and the classical 3D bubble velocity. Unlike in 2D, the 3D short-wavelength bubble velocity does not saturate. The growing 3D bubble acceleration is driven by the unbounded accumulation of vorticity inside the bubble. The vorticity is transferred by mass ablation from the Rayleigh-Taylor spikes to the ablated plasma filling the bubble volume.

Primate translational vestibuloocular reflexes. I. High-frequency dynamics and three-dimensional properties during lateral motion

NASA Technical Reports Server (NTRS)

Angelaki, D. E.; McHenry, M. Q.; Hess, B. J.

2000-01-01

The dynamics and three-dimensional (3-D) properties of the primate translational vestibuloocular reflex (trVOR) for high-frequency (4-12 Hz, +/-0.3-0.4 g) lateral motion were investigated during near-target viewing at center and eccentric targets. Horizontal response gains increased with frequency and depended on target eccentricity. The larger the horizontal and vertical target eccentricity, the steeper the dependence of horizontal response gain on frequency. In addition to horizontal eye movements, robust torsional response components also were present at all frequencies. During center-target fixation, torsional response phase was opposite (anticompensatory) to that expected for an "apparent" tilt response. Instead torsional response components depended systematically on vertical-target eccentricity, increasing in amplitude when looking down and reversing phase when looking up. As a result the trVOR eye velocity vector systematically tilted away from a purely horizontal direction, through an angle that increased with vertical eccentricity with a slope of approximately 0.7. This systematic dependence of torsional eye velocity tilt on vertical eye position suggests that the trVOR might follow the 3-D kinematic requirements that have been shown to govern visually guided eye movements and near-target fixation.

Three-Dimensional Dynamic Bone Histomorphometry

PubMed Central

Slyfield, C.R.; Tkachenko, E.V.; Wilson, D.L.; Hernandez, C.J.

2011-01-01

Dynamic bone histomorphometry is the standard method for measuring bone remodeling at the level of individual events. While dynamic bone histomorphometry is an invaluable tool for understanding osteoporosis and other metabolic bone diseases, the technique’s two-dimensional nature requires the use of stereology and prevents measures of individual remodeling event number and size. Here, we use a novel three-dimensional fluorescence imaging technique to achieve measures of individual resorption cavities and formation events. We perform this three-dimensional histomorphometry approach using a common model of postmenopausal osteoporosis, the ovariectomized rat. The three-dimensional images demonstrate the spatial relationship between resorption cavities and formation events consistent with the hemi-osteonal model of cancellous bone remodeling. Established ovariectomy was associated with significant increases in the number of resorption cavities per unit bone surface (2.38 ± 0.24 mm−2 SHAM v. 3.86 ± 0.35 mm−2 OVX, mean ± SD, p < 0.05) and total volume occupied by cavities per unit bone volume (0.38 ± 0.06% SHAM v. 1.12 ± 0.18% OVX, p < 0.001), but no difference in surface area per resorption cavity, maximum cavity depth, or cavity volume. Additionally, we find that established ovariectomy is associated with increased size of bone formation events due to merging of formation events (23,700 ± 6,890 μm2 SHAM v. 33,300 ± 7,950 μm2 OVX). No differences in mineral apposition rate (determined in 3D) were associated with established ovariectomy. That established estrogen depletion is associated with increased number of remodeling events with only subtle changes in remodeling event size suggests that circulating estrogens may have their primary effect on the origination of new basic multicellular units with relatively little effect on the progression and termination of active remodeling events. PMID:22028195

Potential for change in US diagnosis of hip dysplasia solely caused by changes in probe orientation: patterns of alpha-angle variation revealed by using three-dimensional US.

PubMed

Jaremko, Jacob L; Mabee, Myles; Swami, Vimarsha G; Jamieson, Lucy; Chow, Kelvin; Thompson, Richard B

2014-12-01

To use three-dimensional ( 3D three-dimensional ) ultrasonography (US) to quantify the alpha-angle variability due to changing probe orientation during two-dimensional ( 2D two-dimensional ) US of the infant hip and its effect on the diagnostic classification of developmental dysplasia of the hip ( DDH developmental dysplasia of the hip ). In this institutional research ethics board-approved prospective study, with parental written informed consent, 13-MHz 3D three-dimensional US was added to initial 2D two-dimensional US for 56 hips in 35 infants (mean age, 41.7 days; range, 4-112 days), 26 of whom were female (mean age, 38.7 days; range, 6-112 days) and nine of whom were male (mean age, 50.2 days; range, 4-111 days). Findings in 20 hips were normal at the initial visit and were initially inconclusive but normalized spontaneously at follow-up in 23 hips; 13 hips were treated for dysplasia. With the computer algorithm, 3D three-dimensional US data were resectioned in planes tilted in 5° increments away from a central plane, as if slowly rotating a 2D two-dimensional US probe, until resulting images no longer met Graf quality criteria. On each acceptable 2D two-dimensional image, two observers measured alpha angles, and descriptive statistics, including mean, standard deviation, and limits of agreement, were computed. Acceptable 2D two-dimensional images were produced over a range of probe orientations averaging 24° (maximum, 45°) from the central plane. Over this range, alpha-angle variation was 19° (upper limit of agreement), leading to alteration of the diagnostic category of hip dysplasia in 54% of hips scanned. Use of 3D three-dimensional US showed that alpha angles measured at routine 2D two-dimensional US of the hip can vary substantially between 2D two-dimensional scans solely because of changes in probe positioning. Not only could normal hips appear dysplastic, but dysplastic hips also could have normal alpha angles. Three-dimensional US can display the full acetabular shape, which might improve DDH developmental dysplasia of the hip assessment accuracy. © RSNA, 2014.

Three-pattern decomposition of global atmospheric circulation: part II—dynamical equations of horizontal, meridional and zonal circulations

NASA Astrophysics Data System (ADS)

Hu, Shujuan; Cheng, Jianbo; Xu, Ming; Chou, Jifan

2018-04-01

The three-pattern decomposition of global atmospheric circulation (TPDGAC) partitions three-dimensional (3D) atmospheric circulation into horizontal, meridional and zonal components to study the 3D structures of global atmospheric circulation. This paper incorporates the three-pattern decomposition model (TPDM) into primitive equations of atmospheric dynamics and establishes a new set of dynamical equations of the horizontal, meridional and zonal circulations in which the operator properties are studied and energy conservation laws are preserved, as in the primitive equations. The physical significance of the newly established equations is demonstrated. Our findings reveal that the new equations are essentially the 3D vorticity equations of atmosphere and that the time evolution rules of the horizontal, meridional and zonal circulations can be described from the perspective of 3D vorticity evolution. The new set of dynamical equations includes decomposed expressions that can be used to explore the source terms of large-scale atmospheric circulation variations. A simplified model is presented to demonstrate the potential applications of the new equations for studying the dynamics of the Rossby, Hadley and Walker circulations. The model shows that the horizontal air temperature anomaly gradient (ATAG) induces changes in meridional and zonal circulations and promotes the baroclinic evolution of the horizontal circulation. The simplified model also indicates that the absolute vorticity of the horizontal circulation is not conserved, and its changes can be described by changes in the vertical vorticities of the meridional and zonal circulations. Moreover, the thermodynamic equation shows that the induced meridional and zonal circulations and advection transport by the horizontal circulation in turn cause a redistribution of the air temperature. The simplified model reveals the fundamental rules between the evolution of the air temperature and the horizontal, meridional and zonal components of global atmospheric circulation.

Three-dimensional printing: technologies, applications, and limitations in neurosurgery.

PubMed

Pucci, Josephine U; Christophe, Brandon R; Sisti, Jonathan A; Connolly, Edward S

2017-09-01

Three-dimensional (3D) printers are a developing technology penetrating a variety of markets, including the medical sector. Since its introduction to the medical field in the late 1980s, 3D printers have constructed a range of devices, such as dentures, hearing aids, and prosthetics. With the ultimate goals of decreasing healthcare costs and improving patient care and outcomes, neurosurgeons are utilizing this dynamic technology, as well. Digital Imaging and Communication in Medicine (DICOM) can be translated into Stereolithography (STL) files, which are then read and methodically built by 3D Printers. Vessels, tumors, and skulls are just a few of the anatomical structures created in a variety of materials, which enable surgeons to conduct research, educate surgeons in training, and improve pre-operative planning without risk to patients. Due to the infancy of the field and a wide range of technologies with varying advantages and disadvantages, there is currently no standard 3D printing process for patient care and medical research. In an effort to enable clinicians to optimize the use of additive manufacturing (AM) technologies, we outline the most suitable 3D printing models and computer-aided design (CAD) software for 3D printing in neurosurgery, their applications, and the limitations that need to be overcome if 3D printers are to become common practice in the neurosurgical field. Copyright © 2017 Elsevier Inc. All rights reserved.

Exact rebinning methods for three-dimensional PET.

PubMed

Liu, X; Defrise, M; Michel, C; Sibomana, M; Comtat, C; Kinahan, P; Townsend, D

1999-08-01

The high computational cost of data processing in volume PET imaging is still hindering the routine application of this successful technique, especially in the case of dynamic studies. This paper describes two new algorithms based on an exact rebinning equation, which can be applied to accelerate the processing of three-dimensional (3-D) PET data. The first algorithm, FOREPROJ, is a fast-forward projection algorithm that allows calculation of the 3-D attenuation correction factors (ACF's) directly from a two-dimensional (2-D) transmission scan, without first reconstructing the attenuation map and then performing a 3-D forward projection. The use of FOREPROJ speeds up the estimation of the 3-D ACF's by more than a factor five. The second algorithm, FOREX, is a rebinning algorithm that is also more than five times faster, compared to the standard reprojection algorithm (3DRP) and does not suffer from the image distortions generated by the even faster approximate Fourier rebinning (FORE) method at large axial apertures. However, FOREX is probably not required by most existing scanners, as the axial apertures are not large enough to show improvements over FORE with clinical data. Both algorithms have been implemented and applied to data simulated for a scanner with a large axial aperture (30 degrees), and also to data acquired with the ECAT HR and the ECAT HR+ scanners. Results demonstrate the excellent accuracy achieved by these algorithms and the important speedup when the sinogram sizes are powers of two.

Alpha models for rotating Navier-Stokes equations in geophysics with nonlinear dispersive regularization

NASA Astrophysics Data System (ADS)

Kim, Bong-Sik

Three dimensional (3D) Navier-Stokes-alpha equations are considered for uniformly rotating geophysical fluid flows (large Coriolis parameter f = 2O). The Navier-Stokes-alpha equations are a nonlinear dispersive regularization of usual Navier-Stokes equations obtained by Lagrangian averaging. The focus is on the existence and global regularity of solutions of the 3D rotating Navier-Stokes-alpha equations and the uniform convergence of these solutions to those of the original 3D rotating Navier-Stokes equations for large Coriolis parameters f as alpha → 0. Methods are based on fast singular oscillating limits and results are obtained for periodic boundary conditions for all domain aspect ratios, including the case of three wave resonances which yields nonlinear "2½-dimensional" limit resonant equations for f → 0. The existence and global regularity of solutions of limit resonant equations is established, uniformly in alpha. Bootstrapping from global regularity of the limit equations, the existence of a regular solution of the full 3D rotating Navier-Stokes-alpha equations for large f for an infinite time is established. Then, the uniform convergence of a regular solution of the 3D rotating Navier-Stokes-alpha equations (alpha ≠ 0) to the one of the original 3D rotating NavierStokes equations (alpha = 0) for f large but fixed as alpha → 0 follows; this implies "shadowing" of trajectories of the limit dynamical systems by those of the perturbed alpha-dynamical systems. All the estimates are uniform in alpha, in contrast with previous estimates in the literature which blow up as alpha → 0. Finally, the existence of global attractors as well as exponential attractors is established for large f and the estimates are uniform in alpha.

Extracting cardiac shapes and motion of the chick embryo heart outflow tract from four-dimensional optical coherence tomography images

NASA Astrophysics Data System (ADS)

Yin, Xin; Liu, Aiping; Thornburg, Kent L.; Wang, Ruikang K.; Rugonyi, Sandra

2012-09-01

Recent advances in optical coherence tomography (OCT), and the development of image reconstruction algorithms, enabled four-dimensional (4-D) (three-dimensional imaging over time) imaging of the embryonic heart. To further analyze and quantify the dynamics of cardiac beating, segmentation procedures that can extract the shape of the heart and its motion are needed. Most previous studies analyzed cardiac image sequences using manually extracted shapes and measurements. However, this is time consuming and subject to inter-operator variability. Automated or semi-automated analyses of 4-D cardiac OCT images, although very desirable, are also extremely challenging. This work proposes a robust algorithm to semi automatically detect and track cardiac tissue layers from 4-D OCT images of early (tubular) embryonic hearts. Our algorithm uses a two-dimensional (2-D) deformable double-line model (DLM) to detect target cardiac tissues. The detection algorithm uses a maximum-likelihood estimator and was successfully applied to 4-D in vivo OCT images of the heart outflow tract of day three chicken embryos. The extracted shapes captured the dynamics of the chick embryonic heart outflow tract wall, enabling further analysis of cardiac motion.

Three dimensional fabrication at small size scales

PubMed Central

Leong, Timothy G.; Zarafshar, Aasiyeh M.; Gracias, David H.

2010-01-01

Despite the fact that we live in a three-dimensional (3D) world and macroscale engineering is 3D, conventional sub-mm scale engineering is inherently two-dimensional (2D). New fabrication and patterning strategies are needed to enable truly three-dimensionally-engineered structures at small size scales. Here, we review strategies that have been developed over the last two decades that seek to enable such millimeter to nanoscale 3D fabrication and patterning. A focus of this review is the strategy of self-assembly, specifically in a biologically inspired, more deterministic form known as self-folding. Self-folding methods can leverage the strengths of lithography to enable the construction of precisely patterned 3D structures and “smart” components. This self-assembling approach is compared with other 3D fabrication paradigms, and its advantages and disadvantages are discussed. PMID:20349446

Rapid, High-Throughput Tracking of Bacterial Motility in 3D via Phase-Contrast Holographic Video Microscopy

PubMed Central

Cheong, Fook Chiong; Wong, Chui Ching; Gao, YunFeng; Nai, Mui Hoon; Cui, Yidan; Park, Sungsu; Kenney, Linda J.; Lim, Chwee Teck

2015-01-01

Tracking fast-swimming bacteria in three dimensions can be extremely challenging with current optical techniques and a microscopic approach that can rapidly acquire volumetric information is required. Here, we introduce phase-contrast holographic video microscopy as a solution for the simultaneous tracking of multiple fast moving cells in three dimensions. This technique uses interference patterns formed between the scattered and the incident field to infer the three-dimensional (3D) position and size of bacteria. Using this optical approach, motility dynamics of multiple bacteria in three dimensions, such as speed and turn angles, can be obtained within minutes. We demonstrated the feasibility of this method by effectively tracking multiple bacteria species, including Escherichia coli, Agrobacterium tumefaciens, and Pseudomonas aeruginosa. In addition, we combined our fast 3D imaging technique with a microfluidic device to present an example of a drug/chemical assay to study effects on bacterial motility. PMID:25762336

Web-based Three-dimensional Virtual Body Structures: W3D-VBS

PubMed Central

Temkin, Bharti; Acosta, Eric; Hatfield, Paul; Onal, Erhan; Tong, Alex

2002-01-01

Major efforts are being made to improve the teaching of human anatomy to foster cognition of visuospatial relationships. The Visible Human Project of the National Library of Medicine makes it possible to create virtual reality-based applications for teaching anatomy. Integration of traditional cadaver and illustration-based methods with Internet-based simulations brings us closer to this goal. Web-based three-dimensional Virtual Body Structures (W3D-VBS) is a next-generation immersive anatomical training system for teaching human anatomy over the Internet. It uses Visible Human data to dynamically explore, select, extract, visualize, manipulate, and stereoscopically palpate realistic virtual body structures with a haptic device. Tracking user’s progress through evaluation tools helps customize lesson plans. A self-guided “virtual tour” of the whole body allows investigation of labeled virtual dissections repetitively, at any time and place a user requires it. PMID:12223495

Tunable electromagnetically induced transparency in coupled three-dimensional split-ring-resonator metamaterials

PubMed Central

Han, Song; Cong, Longqing; Lin, Hai; Xiao, Boxun; Yang, Helin; Singh, Ranjan

2016-01-01

Metamaterials have recently enabled coupling induced transparency due to interference effects in coupled subwavelength resonators. In this work, we present a three dimensional (3-D) metamaterial design with six-fold rotational symmetry that shows electromagnetically induced transparency with a strong polarization dependence to the incident electromagnetic wave due to the ultra-sharp resonance line width as a result of interaction between the constituent meta-atoms. However, when the six-fold rotationally symmetric unit cell design was re-arranged into a fourfold rotational symmetry, we observed the excitation of a polarization insensitive dual-band transparency. Thus, the 3-D split-ring resonators allow new schemes to observe single and multi-band classical analogues of electromagnetically induced transparencies that has huge potential applications in slowing down light, sensing modalities, and filtering functionalities either in the passive mode or the active mode where such effects could be tuned by integrating materials with dynamic properties. PMID:26857034

Web-based three-dimensional Virtual Body Structures: W3D-VBS.

PubMed

Temkin, Bharti; Acosta, Eric; Hatfield, Paul; Onal, Erhan; Tong, Alex

2002-01-01

Major efforts are being made to improve the teaching of human anatomy to foster cognition of visuospatial relationships. The Visible Human Project of the National Library of Medicine makes it possible to create virtual reality-based applications for teaching anatomy. Integration of traditional cadaver and illustration-based methods with Internet-based simulations brings us closer to this goal. Web-based three-dimensional Virtual Body Structures (W3D-VBS) is a next-generation immersive anatomical training system for teaching human anatomy over the Internet. It uses Visible Human data to dynamically explore, select, extract, visualize, manipulate, and stereoscopically palpate realistic virtual body structures with a haptic device. Tracking user's progress through evaluation tools helps customize lesson plans. A self-guided "virtual tour" of the whole body allows investigation of labeled virtual dissections repetitively, at any time and place a user requires it.

3DProIN: Protein-Protein Interaction Networks and Structure Visualization.

PubMed

Li, Hui; Liu, Chunmei

2014-06-14

3DProIN is a computational tool to visualize protein-protein interaction networks in both two dimensional (2D) and three dimensional (3D) view. It models protein-protein interactions in a graph and explores the biologically relevant features of the tertiary structures of each protein in the network. Properties such as color, shape and name of each node (protein) of the network can be edited in either 2D or 3D views. 3DProIN is implemented using 3D Java and C programming languages. The internet crawl technique is also used to parse dynamically grasped protein interactions from protein data bank (PDB). It is a java applet component that is embedded in the web page and it can be used on different platforms including Linux, Mac and Window using web browsers such as Firefox, Internet Explorer, Chrome and Safari. It also was converted into a mac app and submitted to the App store as a free app. Mac users can also download the app from our website. 3DProIN is available for academic research at http://bicompute.appspot.com.

Coherent backscattering enhancement in cavities. Highlights of the role of symmetry.

PubMed

Gallot, Thomas; Catheline, Stefan; Roux, Philippe

2011-04-01

Through experiments and simulations, the consequences of symmetry on coherent backscattering enhancement (CBE) are studied in cavities. Three main results are highlighted. First, the CBE outside the source is observed: (a) on a single symmetric point in a one-dimensional (1-D) cavity, in a disk and in a symmetric chaotic plate; (b) on three symmetric points in a two-dimensional (2-D) rectangle; and (c) on seven symmetric points in a three-dimensional (3-D) parallelepiped cavity. Second, the existence of enhanced intensity lines and planes in 2-D and 3-D simple-shape cavities is demonstrated. Third, it is shown how the anti-symmetry caused by the special boundary conditions is responsible for the existence of a coherent backscattering decrement with a dimensional dependence of R = (½)(d), with d = 1,2,3 as the dimensionality of the cavity.

Application of two- and three-dimensional computational fluid dynamics models to complex ecological stream flows

NASA Astrophysics Data System (ADS)

Shen, Yi; Diplas, Panayiotis

2008-01-01

SummaryComplex flow patterns generated by irregular channel topography, such as boulders, submerged large woody debris, riprap and spur dikes, provide unique habitat for many aquatic organisms. Numerical modeling of the flow structures surrounding these obstructions is challenging, yet it represents an important tool for aquatic habitat assessment. In this study, the ability of two- (2-D) and three-dimensional (3-D) computational fluid dynamics models to reproduce these localized complex flow features is examined. The 3-D model is validated with laboratory data obtained from the literature for the case of a flow around a hemisphere under emergent and submerged conditions. The performance of the 2-D and 3-D models is then evaluated by comparing the numerical results with field measurements of flow around several boulders located at a reach of the Smith River, a regulated mountainous stream, obtained at base and peak flows. Close agreement between measured values and the velocity profiles predicted by the two models is obtained outside the wakes behind the hemisphere and boulders. However, the results suggest that in the vicinity of these obstructions the 3-D model is better suited for reproducing the circulation flow behavior at both low and high discharges. Application of the 2-D and 3-D models to meso-scale stream flows of ecological significance is furthermore demonstrated by using a recently developed spatial hydraulic metric to quantify flow complexity surrounding a number of brown trout spawning sites. It is concluded that the 3-D model can provide a much more accurate description of the heterogeneous velocity patterns favored by many aquatic species over a broad range of flows, especially under deep flow conditions when the various obstructions are submerged. Issues pertaining to selection of appropriate models for a variety of flow regimes and potential implication of the 3-D model on the development of better habitat suitability criteria are discussed. The research suggests ways of improving the modeling practices for ecosystem management studies.

Color Constancy in Two-Dimensional and Three-Dimensional Scenes: Effects of Viewing Methods and Surface Texture.

PubMed

Morimoto, Takuma; Mizokami, Yoko; Yaguchi, Hirohisa; Buck, Steven L

2017-01-01

There has been debate about how and why color constancy may be better in three-dimensional (3-D) scenes than in two-dimensional (2-D) scenes. Although some studies have shown better color constancy for 3-D conditions, the role of specific cues remains unclear. In this study, we compared color constancy for a 3-D miniature room (a real scene consisting of actual objects) and 2-D still images of that room presented on a monitor using three viewing methods: binocular viewing, monocular viewing, and head movement. We found that color constancy was better for the 3-D room; however, color constancy for the 2-D image improved when the viewing method caused the scene to be perceived more like a 3-D scene. Separate measurements of the perceptual 3-D effect of each viewing method also supported these results. An additional experiment comparing a miniature room and its image with and without texture suggested that surface texture of scene objects contributes to color constancy.

A comprehensive study of MPI parallelism in three-dimensional discrete element method (DEM) simulation of complex-shaped granular particles

NASA Astrophysics Data System (ADS)

Yan, Beichuan; Regueiro, Richard A.

2018-02-01

A three-dimensional (3D) DEM code for simulating complex-shaped granular particles is parallelized using message-passing interface (MPI). The concepts of link-block, ghost/border layer, and migration layer are put forward for design of the parallel algorithm, and theoretical scalability function of 3-D DEM scalability and memory usage is derived. Many performance-critical implementation details are managed optimally to achieve high performance and scalability, such as: minimizing communication overhead, maintaining dynamic load balance, handling particle migrations across block borders, transmitting C++ dynamic objects of particles between MPI processes efficiently, eliminating redundant contact information between adjacent MPI processes. The code executes on multiple US Department of Defense (DoD) supercomputers and tests up to 2048 compute nodes for simulating 10 million three-axis ellipsoidal particles. Performance analyses of the code including speedup, efficiency, scalability, and granularity across five orders of magnitude of simulation scale (number of particles) are provided, and they demonstrate high speedup and excellent scalability. It is also discovered that communication time is a decreasing function of the number of compute nodes in strong scaling measurements. The code's capability of simulating a large number of complex-shaped particles on modern supercomputers will be of value in both laboratory studies on micromechanical properties of granular materials and many realistic engineering applications involving granular materials.

Distributed augmented reality with 3-D lung dynamics--a planning tool concept.

PubMed

Hamza-Lup, Felix G; Santhanam, Anand P; Imielińska, Celina; Meeks, Sanford L; Rolland, Jannick P

2007-01-01

Augmented reality (AR) systems add visual information to the world by using advanced display techniques. The advances in miniaturization and reduced hardware costs make some of these systems feasible for applications in a wide set of fields. We present a potential component of the cyber infrastructure for the operating room of the future: a distributed AR-based software-hardware system that allows real-time visualization of three-dimensional (3-D) lung dynamics superimposed directly on the patient's body. Several emergency events (e.g., closed and tension pneumothorax) and surgical procedures related to lung (e.g., lung transplantation, lung volume reduction surgery, surgical treatment of lung infections, lung cancer surgery) could benefit from the proposed prototype.

Integration of Computed Tomography and Three-Dimensional Echocardiography for Hybrid Three-Dimensional Printing in Congenital Heart Disease.

PubMed

Gosnell, Jordan; Pietila, Todd; Samuel, Bennett P; Kurup, Harikrishnan K N; Haw, Marcus P; Vettukattil, Joseph J

2016-12-01

Three-dimensional (3D) printing is an emerging technology aiding diagnostics, education, and interventional, and surgical planning in congenital heart disease (CHD). Three-dimensional printing has been derived from computed tomography, cardiac magnetic resonance, and 3D echocardiography. However, individually the imaging modalities may not provide adequate visualization of complex CHD. The integration of the strengths of two or more imaging modalities has the potential to enhance visualization of cardiac pathomorphology. We describe the feasibility of hybrid 3D printing from two imaging modalities in a patient with congenitally corrected transposition of the great arteries (L-TGA). Hybrid 3D printing may be useful as an additional tool for cardiologists and cardiothoracic surgeons in planning interventions in children and adults with CHD.

Tools for 3D scientific visualization in computational aerodynamics at NASA Ames Research Center

NASA Technical Reports Server (NTRS)

Bancroft, Gordon; Plessel, Todd; Merritt, Fergus; Watson, Val

1989-01-01

Hardware, software, and techniques used by the Fluid Dynamics Division (NASA) for performing visualization of computational aerodynamics, which can be applied to the visualization of flow fields from computer simulations of fluid dynamics about the Space Shuttle, are discussed. Three visualization techniques applied, post-processing, tracking, and steering, are described, as well as the post-processing software packages used, PLOT3D, SURF (Surface Modeller), GAS (Graphical Animation System), and FAST (Flow Analysis software Toolkit). Using post-processing methods a flow simulation was executed on a supercomputer and, after the simulation was complete, the results were processed for viewing. It is shown that the high-resolution, high-performance three-dimensional workstation combined with specially developed display and animation software provides a good tool for analyzing flow field solutions obtained from supercomputers.

Structure and spectral features of H+(H2O)7: Eigen versus Zundel forms.

PubMed

Shin, Ilgyou; Park, Mina; Min, Seung Kyu; Lee, Eun Cheol; Suh, Seung Bum; Kim, Kwang S

2006-12-21

The two dimensional (2D) to three dimensional (3D) transition for the protonated water cluster has been controversial, in particular, for H(+)(H(2)O)(7). For H(+)(H(2)O)(7) the 3D structure is predicted to be lower in energy than the 2D structure at most levels of theory without zero-point energy (ZPE) correction. On the other hand, with ZPE correction it is predicted to be either 2D or 3D depending on the calculational levels. Although the ZPE correction favors the 3D structure at the level of coupled cluster theory with singles, doubles, and perturbative triples excitations [CCSD(T)] using the aug-cc-pVDZ basis set, the result based on the anharmonic zero-point vibrational energy correction favors the 2D structure. Therefore, the authors investigated the energies based on the complete basis set limit scheme (which we devised in an unbiased way) at the resolution of the identity approximation Moller-Plesset second order perturbation theory and CCSD(T) levels, and found that the 2D structure has the lowest energy for H(+)(H(2)O)(7) [though nearly isoenergetic to the 3D structure for D(+)(D(2)O)(7)]. This structure has the Zundel-type configuration, but it shows the quantum probabilistic distribution including some of the Eigen-type configuration. The vibrational spectra of MP2/aug-cc-pVDZ calculations and Car-Parrinello molecular dynamics simulations, taking into account the thermal and dynamic effects, show that the 2D Zundel-type form is in good agreement with experiments.

Structure and spectral features of H+(H2O)7: Eigen versus Zundel forms

NASA Astrophysics Data System (ADS)

Shin, Ilgyou; Park, Mina; Min, Seung Kyu; Lee, Eun Cheol; Suh, Seung Bum; Kim, Kwang S.

2006-12-01

The two dimensional (2D) to three dimensional (3D) transition for the protonated water cluster has been controversial, in particular, for H+(H2O)7. For H+(H2O)7 the 3D structure is predicted to be lower in energy than the 2D structure at most levels of theory without zero-point energy (ZPE) correction. On the other hand, with ZPE correction it is predicted to be either 2D or 3D depending on the calculational levels. Although the ZPE correction favors the 3D structure at the level of coupled cluster theory with singles, doubles, and perturbative triples excitations [CCSD(T)] using the aug-cc-pVDZ basis set, the result based on the anharmonic zero-point vibrational energy correction favors the 2D structure. Therefore, the authors investigated the energies based on the complete basis set limit scheme (which we devised in an unbiased way) at the resolution of the identity approximation Møller-Plesset second order perturbation theory and CCSD(T) levels, and found that the 2D structure has the lowest energy for H+(H2O)7 [though nearly isoenergetic to the 3D structure for D+(D2O)7]. This structure has the Zundel-type configuration, but it shows the quantum probabilistic distribution including some of the Eigen-type configuration. The vibrational spectra of MP2/aug-cc-pVDZ calculations and Car-Parrinello molecular dynamics simulations, taking into account the thermal and dynamic effects, show that the 2D Zundel-type form is in good agreement with experiments.

In vivo multiphoton imaging of human skin: assessment of topical corticosteroid-induced epidermis atrophy and depigmentation

NASA Astrophysics Data System (ADS)

Ait El Madani, Hassan; Tancrède-Bohin, Emmanuelle; Bensussan, Armand; Colonna, Anne; Dupuy, Alain; Bagot, Martine; Pena, Ana-Maria

2012-02-01

Multiphoton microscopy has emerged in the past decade as a promising tool for noninvasive skin imaging. Our aim was to evaluate the potential of multiphoton microscopy to detect topical corticosteroids side effects within the epidermis and to provide new insights into their dynamics. Healthy volunteers were topically treated with clobetasol propionate on a small region of their forearms under overnight occlusion for three weeks. The treated region of each patient was investigated at D0, D7, D15, D22 (end of the treatment), and D60. Our study shows that multiphoton microscopy allows for the detection of corticoid-induced epidermis modifications: thinning of stratum corneum compactum and epidermis, decrease of keratinocytes size, and changes in their morphology from D7 to D22. We also show that multiphoton microscopy enables in vivo three-dimensional (3-D) quantitative assessment of melanin content. We observe that melanin density decreases during treatment and almost completely disappears at D22. Moreover, these alterations are reversible as they are no longer present at D60. Our study demonstrates that multiphoton microscopy is a convenient and powerful tool for noninvasive 3-D dynamical studies of skin integrity and pigmentation.

Three dimensional Lagrangian structures in the Antarctic Polar Vortex.

NASA Astrophysics Data System (ADS)

Mancho, Ana M.; Garcia-Garrido, Victor J.; Curbelo, Jezabel; Niang, Coumba; Mechoso, Carlos R.; Wiggins, Stephen

2017-04-01

Dynamical systems theory has supported the description of transport processes in fluid dynamics. For understanding trajectory patterns in chaotic advection the geometrical approach by Poincaré seeks for spatial structures that separate regions corresponding to qualitatively different types of trajectories. These structures have been referred to as Lagrangian Coherent Structures (LCS), which typically in geophysical flows are well described under the approach of incompressible 2D flows. Different tools have been used to visualize LCS. In this presentation we use Lagrangian Descriptors [1,2,3,4] (function M) for visualizing 3D Lagrangian structures in the atmosphere, in particular in the Antarctic Polar Vortex. The function M is computed in a fully 3D incompressible flow obtained from data provided by the European Centre for Medium-Range Weather Forecast and it is represented in 2D surfaces. We discuss the findings during the final warming that took place in the spring of 1979 [5]. This research is supported by MINECO grant MTM2014-56392-R. Support is acknowledged also from CSIC grant COOPB20265, U.S. NSF grant AGS-1245069 and ONR grant No. N00014- 01-1-0769. C. Niang acknowledges Fundacion Mujeres por Africa and ICMAT Severo Ochoa project SEV-2011-0087 for financial support. [1] C. Mendoza, A. M. Mancho. The hidden geometry of ocean flows. Physical Review Letters 105 (2010), 3, 038501-1-038501-4. [2] A. M. Mancho, S. Wiggins, J. Curbelo, C. Mendoza. Lagrangian Descriptors: A Method for Revealing Phase Space Structures of General Time Dependent Dynamical Systems. Communications in Nonlinear Science and Numerical Simulation. 18 (2013) 3530-3557. [3] C. Lopesino, F. Balibrea-Iniesta, S. Wiggins and A. M. Mancho. Lagrangian descriptors for two dimensional, area preserving autonomous and nonautonomous maps. Communications in Nonlinear Science and Numerical Simulations, 27 (2015) (1-3), 40-51. [4] C. Lopesino, F. Balibrea-Iniesta, V. J. García-Garrido, S. Wiggins, and A. M. Mancho, A. M. A theoretical framework for lagrangian descriptors. International Journal of Bifurcation and Chaos (2017) to appear. [5] The three-dimensional Lagrangian geometry of the Antarctic Polar Vortex circulation. Preprint.

Recognition Of Complex Three Dimensional Objects Using Three Dimensional Moment Invariants

NASA Astrophysics Data System (ADS)

Sadjadi, Firooz A.

1985-01-01

A technique for the recognition of complex three dimensional objects is presented. The complex 3-D objects are represented in terms of their 3-D moment invariants, algebraic expressions that remain invariant independent of the 3-D objects' orientations and locations in the field of view. The technique of 3-D moment invariants has been used successfully for simple 3-D object recognition in the past. In this work we have extended this method for the representation of more complex objects. Two complex objects are represented digitally; their 3-D moment invariants have been calculated, and then the invariancy of these 3-D invariant moment expressions is verified by changing the orientation and the location of the objects in the field of view. The results of this study have significant impact on 3-D robotic vision, 3-D target recognition, scene analysis and artificial intelligence.

Neural dynamics of 3-D surface perception: figure-ground separation and lightness perception.

PubMed

Kelly, F; Grossberg, S

2000-11-01

This article develops the FACADE theory of three-dimensional (3-D) vision to simulate data concerning how two-dimensional pictures give rise to 3-D percepts of occluded and occluding surfaces. The theory suggests how geometrical and contrastive properties of an image can either cooperate or compete when forming the boundary and surface representations that subserve conscious visual percepts. Spatially long-range cooperation and short-range competition work together to separate boundaries of occluding figures from their occluded neighbors, thereby providing sensitivity to T-junctions without the need to assume that T-junction "detectors" exist. Both boundary and surface representations of occluded objects may be amodally completed, whereas the surface representations of unoccluded objects become visible through modal processes. Computer simulations include Bregman-Kanizsa figure-ground separation, Kanizsa stratification, and various lightness percepts, including the Münker-White, Benary cross, and checkerboard percepts.

Optical patterning and dynamics of torons and hopfions in a chiral nematic with photo-tunable equilibrium pitch

NASA Astrophysics Data System (ADS)

Sohn, Hayley; Ackerman, Paul; Smalyukh, Ivan

Three-dimensional (3D) topological solitons arise in field theories ranging from particle physics to condensed matter and cosmology. They are the 3D counterparts of 2D skyrmions (often called ``baby skyrmions''), which attract a great deal of interest in studies of chiral ferromagnets and enable the emerging field of skyrmionics. In chiral nematic liquid crystals, the stability of such solitons is enhanced by the chiral medium's tendency to twist the director field describing the 3D spatial patterns of molecular alignment. However, their experimental realization, control and detailed studies remain limited. We combine experimental realization and numerical modeling of such light-responsive solitonic structures, including elementary torons and hopfions, in confined chiral nematic liquid crystals with photo-tunable cholesteric pitch. We show that the optical tunability of the pitch allows for using low-intensity light to control the soliton stability, dimensions, spatial patterning and dynamics.

A matrix-free implicit unstructured multigrid finite volume method for simulating structural dynamics and fluid structure interaction

NASA Astrophysics Data System (ADS)

Lv, X.; Zhao, Y.; Huang, X. Y.; Xia, G. H.; Su, X. H.

2007-07-01

A new three-dimensional (3D) matrix-free implicit unstructured multigrid finite volume (FV) solver for structural dynamics is presented in this paper. The solver is first validated using classical 2D and 3D cantilever problems. It is shown that very accurate predictions of the fundamental natural frequencies of the problems can be obtained by the solver with fast convergence rates. This method has been integrated into our existing FV compressible solver [X. Lv, Y. Zhao, et al., An efficient parallel/unstructured-multigrid preconditioned implicit method for simulating 3d unsteady compressible flows with moving objects, Journal of Computational Physics 215(2) (2006) 661-690] based on the immersed membrane method (IMM) [X. Lv, Y. Zhao, et al., as mentioned above]. Results for the interaction between the fluid and an immersed fixed-free cantilever are also presented to demonstrate the potential of this integrated fluid-structure interaction approach.

Three-dimensional single-mode nonlinear ablative Rayleigh-Taylor instability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, R.; Betti, R.; Sanz, J.

The nonlinear evolution of the single-mode ablative Rayleigh-Taylor instability is studied in three dimensions. As the mode wavelength approaches the cutoff of the linear spectrum (short-wavelength modes), it is found that the three-dimensional (3D) terminal bubble velocity greatly exceeds both the two-dimensional (2D) value and the classical 3D bubble velocity. Unlike in 2D, the 3D short-wavelength bubble velocity does not saturate. The growing 3D bubble acceleration is driven by the unbounded accumulation of vorticity inside the bubble. As a result, the vorticity is transferred by mass ablation from the Rayleigh-Taylor spikes to the ablated plasma filling the bubble volume.

Dynamics and Control of Three-Dimensional Perching Maneuver under Dynamic Stall Influence

NASA Astrophysics Data System (ADS)

Feroskhan, Mir Alikhan Bin Mohammad

Perching is a type of aggressive maneuver performed by the class 'Aves' species to attain precision point landing with a generally short landing distance. Perching capability is desirable on unmanned aerial vehicles (UAVs) due to its efficient deceleration process that potentially expands the functionality and flight envelope of the aircraft. This dissertation extends the previous works on perching, which is mostly limited to two-dimensional (2D) cases, to its state-of-the-art threedimensional (3D) variety. This dissertation presents the aerodynamic modeling and optimization framework adopted to generate unprecedented variants of the 3D perching maneuver that include the sideslip perching trajectory, which ameliorates the existing 2D perching concept by eliminating the undesirable undershoot and reliance on gravity. The sideslip perching technique methodically utilizes the lateral and longitudinal drag mechanisms through consecutive phases of yawing and pitching-up motion. Since perching maneuver involves high rates of change in the angles of attack and large turn rates, introduction of three internal variables thus becomes necessary for addressing the influence of dynamic stall delay on the UAV's transient post-stall behavior. These variables are then integrated into a static nonlinear aerodynamic model, developed using empirical and analytical methods, and into an optimization framework that generates a trajectory of sideslip perching maneuver, acquiring over 70% velocity reduction. An impact study of the dynamic stall influence on the optimal perching trajectories suggests that consideration of dynamic stall delay is essential due to the significant discrepancies in the corresponding control inputs required. A comparative study between 2D and 3D perching is also conducted to examine the different drag mechanisms employed by 2D and 3D perching respectively. 3D perching is presented as a more efficient deceleration technique with respect to spatial costs and initial altitude range. Contraction analysis is shown to be a useful technique in identifying the state variables that are required to be tracked for attaining stability of optimal perching trajectories. Based on the selected tracking variables, two sliding control strategies are proposed and comparatively examined to close the control loop and provide the required robustness and convergence to the optimal perching trajectory in the presence of perturbations and dynamic stall model inaccuracies. This dissertation concludes that the sliding controller with the adaptive gain feature is more effective and essential in providing better tracking performance through illustrations of the corresponding convergence area and at higher intensity of perturbations.

Microfabrication and Test of a Three-Dimensional Polymer Hydro-focusing Unit for Flow Cytometry Applications

NASA Technical Reports Server (NTRS)

Yang, Ren; Feeback, Daniel L.; Wang, Wanjun

2004-01-01

This paper details a novel three-dimensional (3D) hydro-focusing micro cell sorter for micro flow cytometry applications. The unit was microfabricated by means of SU-8 3D lithography. The 3D microstructure for coaxial sheathing was designed, microfabricated, and tested. Three-dimensional hydro-focusing capability was demonstrated with an experiment to sort labeled tanned sheep erythrocytes (red blood cells). This polymer hydro-focusing microstructure is easily microfabricated and integrated with other polymer microfluidic structures.

Microfabrication and Test of a Three-Dimensional Polymer Hydro-Focusing Unit for Flow Cytometry Applications

NASA Technical Reports Server (NTRS)

Yang, Ren; Feedback, Daniel L.; Wang, Wanjun

2004-01-01

This paper details a novel three-dimensional (3D) hydro-focusing micro cell sorter for micro flow cytometry applications. The unit was micro-fabricated by means of SU-8 3D lithography. The 3D microstructure for coaxial sheathing was designed, micro-fabricated, and tested. Three-dimensional hydrofocusing capability was demonstrated with an experiment to sort labeled tanned sheep erythrocytes (red blood cells). This polymer hydro-focusing microstructure is easily micro-fabricated and integrated with other polymer microfluidic structures.

4D Magnetic Resonance Velocimetry in a 3D printed brain aneurysm

NASA Astrophysics Data System (ADS)

Amili, Omid; Schiavazzi, Daniele; Coletti, Filippo

2016-11-01

Cerebral aneurysms are of great clinical importance. It is believed that hemodynamics play a critical role in the development, growth, and rupture of brain arteries with such condition. The flow structure in the aneurysm sac is complex, unsteady, and three-dimensional. Therefore the time-resolved measurement of the three-dimensional three-component velocity field is crucial to predict the clinical outcome. In this study magnetic resonance velocimetry is used to assess the fluid dynamics inside a 3D printed model of a giant intracranial aneurysm. We reach sub-millimeter resolution while resolving sixteen instances within the cardiac cycle. The physiological flow waveform is imposed using an in-house built pump in a flow circuit where the cardiovascular impedance is matched. The flow evolution over time is reconstructed in detail. The complex flow structure is characterized by vortical and helical motions that reside in the aneurysm for most part of the cycle. The 4D pressured distribution is also reconstructed from the velocity field. The present case study was used in a previous CFD challenge, therefore these results may provide useful experimental comparison for simulations performed by other research groups.

Advanced development of BEM for elastic and inelastic dynamic analysis of solids

NASA Technical Reports Server (NTRS)

Banerjee, P. K.; Ahmad, S.; Wang, H. C.

1989-01-01

Direct Boundary Element formulations and their numerical implementation for periodic and transient elastic as well as inelastic transient dynamic analyses of two-dimensional, axisymmetric and three-dimensional solids are presented. The inelastic formulation is based on an initial stress approach and is the first of its kind in the field of Boundary Element Methods. This formulation employs the Navier-Cauchy equation of motion, Graffi's dynamic reciprocal theorem, Stokes' fundamental solution, and the divergence theorem, together with kinematical and constitutive equations to obtain the pertinent integral equations of the problem in the time domain within the context of the small displacement theory of elastoplasticity. The dynamic (periodic, transient as well as nonlinear transient) formulations have been applied to a range of problems. The numerical formulations presented here are included in the BEST3D and GPBEST systems.

Ultrafast energy- and momentum-resolved dynamics of magnetic correlations in the photo-doped Mott insulator Sr 2IrO 4

DOE PAGES

Dean, M. P. M.; Cao, Y.; Liu, X.; ...

2016-05-09

Measuring how the magnetic correlations evolve in doped Mott insulators has greatly improved our understanding of the pseudogap, non-Fermi liquids and high-temperature superconductivity 1, 2, 3, 4. Recently, photo-excitation has been used to induce similarly exotic states transiently 5, 6, 7. However, the lack of available probes of magnetic correlations in the time domain hinders our understanding of these photo-induced states and how they could be controlled. Here, we implement magnetic resonant inelastic X-ray scattering at a free-electron laser to directly determine the magnetic dynamics after photo-doping the Mott insulator Sr 2IrO 4. We find that the non-equilibrium state, 2more » ps after the excitation, exhibits strongly suppressed long-range magnetic order, but hosts photo-carriers that induce strong, non-thermal magnetic correlations. These two-dimensional (2D) in-plane Néel correlations recover within a few picoseconds, whereas the three-dimensional (3D) long-range magnetic order restores on a fluence-dependent timescale of a few hundred picoseconds. In conclusion, the marked difference in these two timescales implies that the dimensionality of magnetic correlations is vital for our understanding of ultrafast magnetic dynamics.« less

MPACT Theory Manual, Version 2.2.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Downar, Thomas; Collins, Benjamin S.; Gehin, Jess C.

2016-06-09

This theory manual describes the three-dimensional (3-D) whole-core, pin-resolved transport calculation methodology employed in the MPACT code. To provide sub-pin level power distributions with sufficient accuracy, MPACT employs the method of characteristics (MOC) solutions in the framework of a 3-D coarse mesh finite difference (CMFD) formulation. MPACT provides a 3D MOC solution, but also a 2D/1D solution in which the 2D planar solution is provided by MOC and the axial coupling is resolved by one-dimensional (1-D) lower order (diffusion or P3) solutions. In Chapter 2 of the manual, the MOC methodology is described for calculating the regional angular and scalarmore » fluxes from the Boltzmann transport equation. In Chapter 3, the 2D/1D methodology is described, together with the description of the CMFD iteration process involving dynamic homogenization and solution of the multigroup CMFD linear system. A description of the MPACT depletion algorithm is given in Chapter 4, followed by a discussion of the subgroup and ESSM resonance processing methods in Chapter 5. The final Chapter 6 describes a simplified thermal hydraulics model in MPACT.« less

Virtual Diagnostics Interface: Real Time Comparison of Experimental Data and CFD Predictions for a NASA Ares I-Like Vehicle

NASA Technical Reports Server (NTRS)

Schwartz, Richard J.; Fleming, Gary A.

2007-01-01

Virtual Diagnostics Interface technology, or ViDI, is a suite of techniques utilizing image processing, data handling and three-dimensional computer graphics. These techniques aid in the design, implementation, and analysis of complex aerospace experiments. LiveView3D is a software application component of ViDI used to display experimental wind tunnel data in real-time within an interactive, three-dimensional virtual environment. The LiveView3D software application was under development at NASA Langley Research Center (LaRC) for nearly three years. LiveView3D recently was upgraded to perform real-time (as well as post-test) comparisons of experimental data with pre-computed Computational Fluid Dynamics (CFD) predictions. This capability was utilized to compare experimental measurements with CFD predictions of the surface pressure distribution of the NASA Ares I Crew Launch Vehicle (CLV) - like vehicle when tested in the NASA LaRC Unitary Plan Wind Tunnel (UPWT) in December 2006 - January 2007 timeframe. The wind tunnel tests were conducted to develop a database of experimentally-measured aerodynamic performance of the CLV-like configuration for validation of CFD predictive codes.

Explicit densities of multidimensional ballistic Lévy walks.

PubMed

Magdziarz, Marcin; Zorawik, Tomasz

2016-08-01

Lévy walks have proved to be useful models of stochastic dynamics with a number of applications in the modeling of real-life phenomena. In this paper we derive explicit formulas for densities of the two- (2D) and three-dimensional (3D) ballistic Lévy walks, which are most important in applications. It turns out that in the 3D case the densities are given by elementary functions. The densities of the 2D Lévy walks are expressed in terms of hypergeometric functions and the right-side Riemann-Liouville fractional derivative, which allows us to efficiently evaluate them numerically. The theoretical results agree perfectly with Monte Carlo simulations.

Quantitative 3D evolution of colloidal nanoparticle oxidation in solution

DOE PAGES

Sun, Yugang; Zuo, Xiaobing; Sankaranarayanan, Subramanian K. R. S.; ...

2017-04-21

Real-time tracking three-dimensional (3D) evolution of colloidal nanoparticles in solution is essential for understanding complex mechanisms involved in nanoparticle growth and transformation. We simultaneously use time-resolved small-angle and wide-angle x-ray scattering to monitor oxidation of highly uniform colloidal iron nanoparticles, enabling the reconstruction of intermediate 3D morphologies of the nanoparticles with a spatial resolution of ~5 Å. The in-situ probing combined with large-scale reactive molecular dynamics simulations reveals the transformational details from the solid metal nanoparticles to hollow metal oxide nanoshells via nanoscale Kirkendall process, for example, coalescence of voids upon their growth, reversing of mass diffusion direction depending onmore » crystallinity, and so forth. In conclusion, our results highlight the complex interplay between defect chemistry and defect dynamics in determining nanoparticle transformation and formation.« less

Computer-aided modeling and prediction of performance of the modified Lundell class of alternators in space station solar dynamic power systems

NASA Technical Reports Server (NTRS)

Demerdash, Nabeel A. O.; Wang, Ren-Hong

1988-01-01

The main purpose of this project is the development of computer-aided models for purposes of studying the effects of various design changes on the parameters and performance characteristics of the modified Lundell class of alternators (MLA) as components of a solar dynamic power system supplying electric energy needs in the forthcoming space station. Key to this modeling effort is the computation of magnetic field distribution in MLAs. Since the nature of the magnetic field is three-dimensional, the first step in the investigation was to apply the finite element method to discretize volume, using the tetrahedron as the basic 3-D element. Details of the stator 3-D finite element grid are given. A preliminary look at the early stage of a 3-D rotor grid is presented.

Quantitative 3D evolution of colloidal nanoparticle oxidation in solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Yugang; Zuo, Xiaobing; Sankaranarayanan, Subramanian K. R. S.

Real-time tracking three-dimensional (3D) evolution of colloidal nanoparticles in solution is essential for understanding complex mechanisms involved in nanoparticle growth and transformation. We simultaneously use time-resolved small-angle and wide-angle x-ray scattering to monitor oxidation of highly uniform colloidal iron nanoparticles, enabling the reconstruction of intermediate 3D morphologies of the nanoparticles with a spatial resolution of ~5 Å. The in-situ probing combined with large-scale reactive molecular dynamics simulations reveals the transformational details from the solid metal nanoparticles to hollow metal oxide nanoshells via nanoscale Kirkendall process, for example, coalescence of voids upon their growth, reversing of mass diffusion direction depending onmore » crystallinity, and so forth. In conclusion, our results highlight the complex interplay between defect chemistry and defect dynamics in determining nanoparticle transformation and formation.« less

Liarozole inhibits transforming growth factor-β3–mediated extracellular matrix formation in human three-dimensional leiomyoma cultures

PubMed Central

Levy, Gary; Malik, Minnie; Britten, Joy; Gilden, Melissa; Segars, James; Catherino, William H.

2014-01-01

Objective To investigate the impact of liarozole on transforming growth factor-β3 (TGF-β3) expression, TGF-β3 controlled profibrotic cytokines, and extracellular matrix formation in a three-dimensional (3D) leiomyoma model system. Design Molecular and immunohistochemical analysis in a cell line evaluated in a three-dimensional culture. Setting Laboratory study. Patient(s) None. Intervention(s) Treatment of leiomyoma and myometrial cells with liarozole and TGF-β3 in a three-dimensional culture system. Main Outcome Measure(s) Quantitative real-time reverse-transcriptase polymerase chain reaction and Western blotting to assess fold gene and protein expression of TGF-β3 and TGF-β3 regulated fibrotic cytokines: collagen 1A1 (COL1A1), fibronectin, and versican before and after treatment with liarozole, and confirmatory immunohistochemical stains of treated three-dimensional cultures. Result(s) Both TGF-β3 gene and protein expression were elevated in leiomyoma cells compared with myometrium in two-dimensional and 3D cultures. Treatment with liarozole decreased TGF-β3 gene and protein expression. Extracellular matrix components versican, COL1A1, and fibronectin were also decreased by liarozole treatment in 3D cultures. Treatment of 3D cultures with TGF-β3 increased gene expression and protein production of COL1A1, fibronectin, and versican. Conclusion(s) Liarozole decreased TGF-β3 and TGF-β3–mediated extracellular matrix expression in a 3D uterine leiomyoma culture system. PMID:24825427

Three-dimensional ultrasonic scanning.

PubMed

Fredfeldt, K E; Holm, H H; Pedersen, J F

1984-01-01

Simple experiments which form the basis for a true 3-D demonstration of sectional images are presented and a method for genuine 3-D display of dynamic ultrasound images is described. Eight ultrasound images are recorded with a slightly different angulation of the transducer. The images are extracted from the video signal from a conventional ultrasound scanner and stored in eight digital memories. After recording, each image is displayed on an oscilloscope screen, which is viewed via a fast oscillating mirror. The position of the mirror determines which of the eight images are to be displayed and thereby ensures a correct spatial relationship of the images, resulting in a true 3-D scan presentation.

3D photomechanical model of tooth enamel ablation by Er-laser radiation

NASA Astrophysics Data System (ADS)

Belikov, Andrey V.; Shatilova, Ksenia V.; Skrypnik, Alexei V.

2014-02-01

The three-dimensional (3D) photomechanical model of human tooth enamel ablation is described. It takes into account: the structural peculiarities of enamel, Er-laser beam energy spatial distribution and laser radiation attenuation in the tissue. Dynamics change of enamel coefficient of absorption during ablation is also discussed. We consider the 3D photomechanical model of incomplete removal (modification) of the enamel rods by the pressure of water contained in the enamel pores and heated by laser radiation, and complete removal (ablation) of the enamel rods as result of hydroxyapatite heated by laser radiation and evaporation. Modeling results are in close agreement with the experimental results.

Decoupling diffusional from dimensional control of signaling in 3D culture reveals a role for myosin in tubulogenesis

PubMed Central

Raghavan, Srivatsan; Shen, Colette J.; Desai, Ravi A.; Sniadecki, Nathan J.; Nelson, Celeste M.; Chen, Christopher S.

2010-01-01

We present a novel microfabricated platform to culture cells within arrays of micrometer-scale three-dimensional (3D) extracellular matrix scaffolds (microgels). These microscale cultures eliminate diffusion barriers that are intrinsic to traditional 3D culture systems (macrogels) and enable uniform cytokine stimulation of the entire culture population, as well as allow immunolabeling, imaging and population-based biochemical assays across the relatively coplanar microgels. Examining early signaling associated with hepatocyte growth factor (HGF)-mediated scattering and tubulogenesis of MDCK cells revealed that 3D culture modulates cellular responses both through dimensionality and altered stimulation rates. Comparing responses in 2D culture, microgels and macrogels demonstrated that HGF-induced ERK signaling was driven by the dynamics of stimulation and not by whether cells were in a 2D or 3D environment, and that this ERK signaling was equally important for HGF-induced cell scattering on 2D substrates and tubulogenesis in 3D. By contrast, we discovered a specific HGF-induced increase in myosin expression leading to sustained downregulation of myosin activity that occurred only within 3D contexts and was required for 3D tubulogenesis but not 2D scattering. Interestingly, although absent in cells on collagen-coated plates, downregulation of myosin activity also occurred for cells on collagen gels, but was transient and mediated by a combination of myosin dephosphorylation and enhanced myosin expression. Furthermore, upregulating myosin activity via siRNA targeted to a myosin phosphatase did not attenuate scattering in 2D but did inhibit tubulogenesis in 3D. Together, these results demonstrate that cellular responses to soluble cues in 3D culture are regulated by both rates of stimulation and by matrix dimensionality, and highlight the importance of decoupling these effects to identify early signals relevant to cellular function in 3D environments. PMID:20682635

Preoperative planning and real-time assisted navigation by three-dimensional individual digital model in partial nephrectomy with three-dimensional laparoscopic system.

PubMed

Wang, Dongwen; Zhang, Bin; Yuan, Xiaobin; Zhang, Xuhui; Liu, Chen

2015-09-01

To evaluate the feasibility and effectiveness of preoperative planning and real-time assisted surgical navigation for three-dimensional laparoscopic partial nephrectomy under the guidance of three-dimensional individual digital model (3D-IDM) created using three-dimensional medical image reconstructing and guiding system (3D-MIRGS). Between May 2012 and February 2014, 44 patients with cT1 renal tumors underwent retroperitoneal laparoscopic partial nephrectomy (LPN) using a three-dimensional laparoscopic system. The 3D-IDMs were created using the 3D-MIRGS in 21 patients (3D-MIRGS group) between February 2013 and February 2014. After preoperative planning, operations were real-time assisted using composite 3D-IDMs, which were fused with two-dimensional retrolaparoscopic images. The remaining 23 patients underwent surgery without 3D-MIRGS between May 2012 and February 2013; 14 of these patients were selected as a control group. Preoperative aspects and dimensions used for an anatomical score, "radius; exophytic/endophytic; nearness; anterior/posterior; location" nephrometry score, tumor size, operative time (OT), segmental renal artery clamping (SRAC) time, estimated blood loss (EBL), postoperative hospitalization, the preoperative serum creatinine level and ipsilateral glomerular filtration rate (GFR), as well as postoperative 6-month data were compared between groups. All the SRAC procedures were technically successful, and each targeted tumor was excised completely; final pathological margin results were negative. The OT was shorter (159.0 vs. 193.2 min; p < 0.001), and EBL (148.1 vs. 176.1 mL; p < 0.001) was reduced in the 3D-MIRGS group compared with controls. No statistically significant differences in SRAC time or postoperative hospitalization were found between the groups. Neither group showed any statistically significant increases in serum creatinine level or decreases in ipsilateral GFR postoperatively. Preoperative planning and real-time assisted surgical navigation using the 3D-IDM reconstructed from 3D-MIRGS and combined with the 3D laparoscopic system can facilitate LPN and result in precise SRAC and accurate excision of tumor that is both effective and safe.

Three-Dimensional Geometric Modeling of Membrane-bound Organelles in Ventricular Myocytes: Bridging the Gap between Microscopic Imaging and Mathematical Simulation

PubMed Central

Yu, Zeyun; Holst, Michael J.; Hayashi, Takeharu; Bajaj, Chandrajit L.; Ellisman, Mark H.; McCammon, J. Andrew; Hoshijima, Masahiko

2009-01-01

A general framework of image-based geometric processing is presented to bridge the gap between three-dimensional (3D) imaging that provides structural details of a biological system and mathematical simulation where high-quality surface or volumetric meshes are required. A 3D density map is processed in the order of image pre-processing (contrast enhancement and anisotropic filtering), feature extraction (boundary segmentation and skeletonization), and high-quality and realistic surface (triangular) and volumetric (tetrahedral) mesh generation. While the tool-chain described is applicable to general types of 3D imaging data, the performance is demonstrated specifically on membrane-bound organelles in ventricular myocytes that are imaged and reconstructed with electron microscopic (EM) tomography and two-photon microscopy (T-PM). Of particular interest in this study are two types of membrane-bound Ca2+-handling organelles, namely, transverse tubules (T-tubules) and junctional sarcoplasmic reticulum (jSR), both of which play an important role in regulating the excitation-contraction (E-C) coupling through dynamic Ca2+ mobilization in cardiomyocytes. PMID:18835449

Three-dimensional geometric modeling of membrane-bound organelles in ventricular myocytes: bridging the gap between microscopic imaging and mathematical simulation.

PubMed

Yu, Zeyun; Holst, Michael J; Hayashi, Takeharu; Bajaj, Chandrajit L; Ellisman, Mark H; McCammon, J Andrew; Hoshijima, Masahiko

2008-12-01

A general framework of image-based geometric processing is presented to bridge the gap between three-dimensional (3D) imaging that provides structural details of a biological system and mathematical simulation where high-quality surface or volumetric meshes are required. A 3D density map is processed in the order of image pre-processing (contrast enhancement and anisotropic filtering), feature extraction (boundary segmentation and skeletonization), and high-quality and realistic surface (triangular) and volumetric (tetrahedral) mesh generation. While the tool-chain described is applicable to general types of 3D imaging data, the performance is demonstrated specifically on membrane-bound organelles in ventricular myocytes that are imaged and reconstructed with electron microscopic (EM) tomography and two-photon microscopy (T-PM). Of particular interest in this study are two types of membrane-bound Ca(2+)-handling organelles, namely, transverse tubules (T-tubules) and junctional sarcoplasmic reticulum (jSR), both of which play an important role in regulating the excitation-contraction (E-C) coupling through dynamic Ca(2+) mobilization in cardiomyocytes.

NASA-VOF3D: A three-dimensional computer program for incompressible flows with free surfaces

NASA Astrophysics Data System (ADS)

Torrey, M. D.; Mjolsness, R. C.; Stein, L. R.

1987-07-01

Presented is the NASA-VOF3D three-dimensional, transient, free-surface hydrodynamics program. This three-dimensional extension of NASA-VOF2D will, in principle, permit treatment in full three-dimensional generality of the wide variety of applications that could be treated by NASA-VOF2D only within the two-dimensional idealization. In particular, it, like NASA-VOF2D, is specifically designed to calculate confined flows in a low g environment. The code is presently restricted to cylindrical geometry. The code is based on the fractional volume-of-fluid method and allows multiple free surfaces with surface tension and wall adhesion. It also has a partial cell treatment that allows curved boundaries and internal obstacles. This report provides a brief discussion of the numerical method, a code listing, and some sample problems.

Modeling liver physiology: combining fractals, imaging and animation.

PubMed

Lin, Debbie W; Johnson, Scott; Hunt, C Anthony

2004-01-01

Physiological modeling of vascular and microvascular networks in several key human organ systems is critical for a deeper understanding of pharmacology and the effect of pharmacotherapies on disease. Like the lung and the kidney, the morphology of its vascular and microvascular system plays a major role in its functional capability. To understand liver function in absorption and metabolism of food and drugs, one must examine the morphology and physiology at both higher and lower level liver function. We have developed validated virtualized dynamic three dimensional (3D) models of liver secondary units and primary units by combining a number of different methods: three-dimensional rendering, fractals, and animation. We have simulated particle dynamics in the liver secondary unit. The resulting models are suitable for use in helping researchers easily visualize and gain intuition on results of in silico liver experiments.

A 2.5-dimensional method for the prediction of structure-borne low-frequency noise from concrete rail transit bridges.

PubMed

Li, Qi; Song, Xiaodong; Wu, Dingjun

2014-05-01

Predicting structure-borne noise from bridges subjected to moving trains using the three-dimensional (3D) boundary element method (BEM) is a time consuming process. This paper presents a two-and-a-half dimensional (2.5D) BEM-based procedure for simulating bridge-borne low-frequency noise with higher efficiency, yet no loss of accuracy. The two-dimensional (2D) BEM of a bridge with a constant cross section along the track direction is adopted to calculate the spatial modal acoustic transfer vectors (MATVs) of the bridge using the space-wave number transforms of its 3D modal shapes. The MATVs calculated using the 2.5D method are then validated by those computed using the 3D BEM. The bridge-borne noise is finally obtained through the MATVs and modal coordinate responses of the bridge, considering time-varying vehicle-track-bridge dynamic interaction. The presented procedure is applied to predict the sound pressure radiating from a U-shaped concrete bridge, and the computed results are compared with those obtained from field tests on Shanghai rail transit line 8. The numerical results match well with the measured results in both time and frequency domains at near-field points. Nevertheless, the computed results are smaller than the measured ones for far-field points, mainly due to the sound radiation from adjacent spans neglected in the current model.

Quantum Dynamics Study of the Isotopic Effect on Capture Reactions: HD, D2 + CH3

NASA Technical Reports Server (NTRS)

Wang, Dunyou; Kwak, Dochan (Technical Monitor)

2002-01-01

Time-dependent wave-packet-propagation calculations are reported for the isotopic reactions, HD + CH3 and D2 + CH3, in six degrees of freedom and for zero total angular momentum. Initial state selected reaction probabilities for different initial rotational-vibrational states are presented in this study. This study shows that excitations of the HD(D2) enhances the reactivities; whereas the excitations of the CH3 umbrella mode have the opposite effects. This is consistent with the reaction of H2 + CH3. The comparison of these three isotopic reactions also shows the isotopic effects in the initial-state-selected reaction probabilities. The cumulative reaction probabilities (CRP) are obtained by summing over initial-state-selected reaction probabilities. The energy-shift approximation to account for the contribution of degrees of freedom missing in the six dimensionality calculation is employed to obtain approximate full-dimensional CRPs. The rate constant comparison shows H2 + CH3 reaction has the biggest reactivity, then HD + CH3, and D2 + CH3 has the smallest.

Scaling analysis of [Fe(pyrazole)4]2[Nb(CN)8] molecular magnet

NASA Astrophysics Data System (ADS)

Konieczny, P.; Pełka, R.; Zieliński, P. M.; Pratt, F. L.; Pinkowicz, D.; Sieklucka, B.; Wasiutyński, T.

2013-10-01

The critical behaviour of the three dimensional (3D) molecular magnet {[FeII(pirazol)4]2[NbIV(CN)8]·4H2O}n has been studied with the use of experimental techniques such as ac magnetometry and zero field μSR spectroscopy. The sample orders magnetically below Tc=7.8 K. The measurements allowed to determine static exponents β, γ, and the dynamic exponent w. The resulting exponent values indicate that the studied system belongs to the universality class of the 3D Heisenberg model.

Dislocation Dissociation Strongly Influences on Frank—Read Source Nucleation and Microplasticy of Materials with Low Stacking Fault Energy

NASA Astrophysics Data System (ADS)

Huang, Min-Sheng; Zhu, Ya-Xin; Li, Zhen-Huan

2014-04-01

The influence of dislocation dissociation on the evolution of Frank—Read (F-R) sources is studied using a three-dimensional discrete dislocation dynamics simulation (3D-DDD). The classical Orowan nucleation stress and recently proposed Benzerga nucleation time models for F-R sources are improved. This work shows that it is necessary to introduce the dislocation dissociation scheme into 3D-DDD simulation, especially for simulations on micro-plasticity of small sized materials with low stacking fault energy.

Real three-dimensional objects: effects on mental rotation.

PubMed

Felix, Michael C; Parker, Joshua D; Lee, Charles; Gabriel, Kara I

2011-08-01

The current experiment investigated real three-dimensional (3D) objects with regard to performance on a mental rotation task and whether the appearance of sex differences may be mediated by experiences with spatially related activities. 40 men and 40 women were presented with alternating timed trials consisting of real-3D objects or two-dimensional illustrations of 3D objects. Sex differences in spatially related activities did not significantly influence the finding that men outperformed women on mental rotation of either stimulus type. However, on measures related to spatial activities, self-reported proficiency using maps correlated positively with performance only on trials with illustrations whereas self-reported proficiency using GPS correlated negatively with performance regardless of stimulus dimensionality. Findings may be interpreted as suggesting that rotating real-3D objects utilizes distinct but overlapping spatial skills compared to rotating two-dimensional representations of 3D objects, and real-3D objects can enhance mental rotation performance.

Heteroleptic metallosupramolecular racks, rectangles, and trigonal prisms: stoichiometry-controlled reversible interconversion.

PubMed

Neogi, Subhadip; Lorenz, Yvonne; Engeser, Marianne; Samanta, Debabrata; Schmittel, Michael

2013-06-17

A simple approach toward preparation of heteroleptic two-dimensional (2D) rectangles and three-dimensional (3D) triangular prisms is described utilizing the HETPYP (HETeroleptic PYridyl and Phenanthroline metal complexes) concept. By mixing metal-loaded linear bisphenanthrolines of varying lengths with diverse (multi)pyridine (py) ligands in a proper ratio, six different self-assembled architectures arise cleanly and spontaneously in the absence of any template. They are characterized by (1)H and DOSY NMR, ESI-FT-ICR mass spectrometry as well as by Job plots and UV-vis titrations. Density functional theory (DFT) computations provide information about each structure. A stoichiometry-controlled supramolecule-to-supramolecule interconversion based on the relative amounts of metal bisphenanthroline and bipyridine forces the rectangular assembly to reorganize to a rack architecture and back to the rectangle, as clearly supported by variable temperature and DOSY NMR as well as dynamic light scattering data. The highly dynamic nature of the assemblies represents a promising starting point for constitutional dynamic materials.

Energy transfer in turbulence under rotation

NASA Astrophysics Data System (ADS)

Buzzicotti, Michele; Aluie, Hussein; Biferale, Luca; Linkmann, Moritz

2018-03-01

It is known that rapidly rotating turbulent flows are characterized by the emergence of simultaneous upscale and downscale energy transfer. Indeed, both numerics and experiments show the formation of large-scale anisotropic vortices together with the development of small-scale dissipative structures. However the organization of interactions leading to this complex dynamics remains unclear. Two different mechanisms are known to be able to transfer energy upscale in a turbulent flow. The first is characterized by two-dimensional interactions among triads lying on the two-dimensional, three-component (2D3C)/slow manifold, namely on the Fourier plane perpendicular to the rotation axis. The second mechanism is three-dimensional and consists of interactions between triads with the same sign of helicity (homochiral). Here, we present a detailed numerical study of rotating flows using a suite of high-Reynolds-number direct numerical simulations (DNS) within different parameter regimes to analyze both upscale and downscale cascade ranges. We find that the upscale cascade at wave numbers close to the forcing scale is generated by increasingly dominant homochiral interactions which couple the three-dimensional bulk and the 2D3C plane. This coupling produces an accumulation of energy in the 2D3C plane, which then transfers energy to smaller wave numbers thanks to the two-dimensional mechanism. In the forward cascade range, we find that the energy transfer is dominated by heterochiral triads and is dominated primarily by interaction within the fast manifold where kz≠0 . We further analyze the energy transfer in different regions in the real-space domain. In particular, we distinguish high-strain from high-vorticity regions and we uncover that while the mean transfer is produced inside regions of strain, the rare but extreme events of energy transfer occur primarily inside the large-scale column vortices.

The investigation of tethered satellite system dynamics

NASA Technical Reports Server (NTRS)

Lorenzini, E.

1985-01-01

A progress report is presented that deals with three major topics related to Tethered Satellite System Dynamics. The SAO rotational dynamics computer code was updated. The program is now suitable to deal with inclined orbits. The output has been also modified in order to show the satellite Euler angles referred to the rotating orbital frame. The three-dimensional high resolution computer program SLACK3 was developed. The code simulates the three-dimensional dynamics of a tether going slack taking into account the effect produced by boom rotations. Preliminary simulations on the three-dimensional dynamics of a recoiling slack tether are shown in this report. A program to evaluate the electric potential around a severed tether is immersed in a plasma. The potential is computed on a three-dimensional grid axially symmetric with respect to the tether longitudinal axis. The electric potential variations due to the plasma are presently under investigation.

Making three-dimensional echocardiography more tangible: a workflow for three-dimensional printing with echocardiographic data.

PubMed

Mashari, Azad; Montealegre-Gallegos, Mario; Knio, Ziyad; Yeh, Lu; Jeganathan, Jelliffe; Matyal, Robina; Khabbaz, Kamal R; Mahmood, Feroze

2016-12-01

Three-dimensional (3D) printing is a rapidly evolving technology with several potential applications in the diagnosis and management of cardiac disease. Recently, 3D printing (i.e. rapid prototyping) derived from 3D transesophageal echocardiography (TEE) has become possible. Due to the multiple steps involved and the specific equipment required for each step, it might be difficult to start implementing echocardiography-derived 3D printing in a clinical setting. In this review, we provide an overview of this process, including its logistics and organization of tools and materials, 3D TEE image acquisition strategies, data export, format conversion, segmentation, and printing. Generation of patient-specific models of cardiac anatomy from echocardiographic data is a feasible, practical application of 3D printing technology. © 2016 The authors.

Ab initio RNA folding by discrete molecular dynamics: From structure prediction to folding mechanisms

PubMed Central

Ding, Feng; Sharma, Shantanu; Chalasani, Poornima; Demidov, Vadim V.; Broude, Natalia E.; Dokholyan, Nikolay V.

2008-01-01

RNA molecules with novel functions have revived interest in the accurate prediction of RNA three-dimensional (3D) structure and folding dynamics. However, existing methods are inefficient in automated 3D structure prediction. Here, we report a robust computational approach for rapid folding of RNA molecules. We develop a simplified RNA model for discrete molecular dynamics (DMD) simulations, incorporating base-pairing and base-stacking interactions. We demonstrate correct folding of 150 structurally diverse RNA sequences. The majority of DMD-predicted 3D structures have <4 Å deviations from experimental structures. The secondary structures corresponding to the predicted 3D structures consist of 94% native base-pair interactions. Folding thermodynamics and kinetics of tRNAPhe, pseudoknots, and mRNA fragments in DMD simulations are in agreement with previous experimental findings. Folding of RNA molecules features transient, non-native conformations, suggesting non-hierarchical RNA folding. Our method allows rapid conformational sampling of RNA folding, with computational time increasing linearly with RNA length. We envision this approach as a promising tool for RNA structural and functional analyses. PMID:18456842

Study of optical design of three-dimensional digital ophthalmoscopes.

PubMed

Fang, Yi-Chin; Yen, Chih-Ta; Chu, Chin-Hsien

2015-10-01

This study primarily involves using optical zoom structures to design a three-dimensional (3D) human-eye optical sensory system with infrared and visible light. According to experimental data on two-dimensional (2D) and 3D images, human-eye recognition of 3D images is substantially higher (approximately 13.182%) than that of 2D images. Thus, 3D images are more effective than 2D images when they are used at work or in high-recognition devices. In the optical system design, infrared and visible light wavebands were incorporated as light sources to perform simulations. The results can be used to facilitate the design of optical systems suitable for 3D digital ophthalmoscopes.

Enhancement of viability of muscle precursor cells on 3D scaffold in a perfusion bioreactor.

PubMed

Cimetta, E; Flaibani, M; Mella, M; Serena, E; Boldrin, L; De Coppi, P; Elvassore, N

2007-05-01

The aim of this study was to develop a methodology for the in vitro expansion of skeletal-muscle precursor cells (SMPC) in a three-dimensional (3D) environment in order to fabricate a cellularized artificial graft characterized by high density of viable cells and uniform cell distribution over the entire 3D domain. Cell seeding and culture within 3D porous scaffolds by conventional static techniques can lead to a uniform cell distribution only on the scaffold surface, whereas dynamic culture systems have the potential of allowing a uniform growth of SMPCs within the entire scaffold structure. In this work, we designed and developed a perfusion bioreactor able to ensure long-term culture conditions and uniform flow of medium through 3D collagen sponges. A mathematical model to assist the design of the experimental setup and of the operative conditions was developed. The effects of dynamic vs static culture in terms of cell viability and spatial distribution within 3D collagen scaffolds were evaluated at 1, 4 and 7 days and for different flow rates of 1, 2, 3.5 and 4.5 ml/min using C2C12 muscle cell line and SMPCs derived from satellite cells. C2C12 cells, after 7 days of culture in our bioreactor, perfused applying a 3.5 ml/min flow rate, showed a higher viability resulting in a three-fold increase when compared with the same parameter evaluated for cultures kept under static conditions. In addition, dynamic culture resulted in a more uniform 3D cell distribution. The 3.5 ml/min flow rate in the bioreactor was also applied to satellite cell-derived SMPCs cultured on 3D collagen scaffolds. The dynamic culture conditions improved cell viability leading to higher cell density and uniform distribution throughout the entire 3D collagen sponge for both C2C12 and satellite cells.

Rotary culture enhances pre-osteoblast aggregation and mineralization.

PubMed

Facer, S R; Zaharias, R S; Andracki, M E; Lafoon, J; Hunter, S K; Schneider, G B

2005-06-01

Three-dimensional environments have been shown to enhance cell aggregation and osteoblast differentiation. Thus, we hypothesized that three-dimensional (3D) growth environments would enhance the mineralization rate of human embryonic palatal mesenchymal (HEPM) pre-osteoblasts. The objective of this study was to investigate the potential use of rotary cell culture systems (RCCS) as a means to enhance the osteogenic potential of pre-osteoblast cells. HEPM cells were cultured in a RCCS to create 3D enviroments. Tissue culture plastic (2D) cultures served as our control. 3D environments promoted three-dimensional aggregate formations. Increased calcium and phosphorus deposition was significantly enhanced three- to 18-fold (P < 0.001) in 3D cultures as compared with 2D environments. 3D cultures mineralized in 1 wk as compared with the 2D cultures, which took 4 wks, a decrease in time of nearly 75%. In conclusion, our studies demonstrated that 3D environments enhanced osteoblast cell aggregation and mineralization.

An Interactive Preprocessor Program with Graphics for a Three-Dimensional Finite Element Code.

ERIC Educational Resources Information Center

Hamilton, Claude Hayden, III

The development and capabilities of an interactive preprocessor program with graphics for an existing three-dimensional finite element code is presented. This preprocessor program, EDGAP3D, is designed to be used in conjunction with the Texas Three Dimensional Grain Analysis Program (TXCAP3D). The code presented in this research is capable of the…

Quantification of instantaneous flow rate and dynamically changing effective orifice area using a geometry independent three-dimensional digital color Doppler method: An in vitro study mimicking mitral regurgitation.

PubMed

Li, Xiaokui; Wanitkun, Suthep; Li, Xiang-Ning; Hashimoto, Ikuo; Mori, Yoshiki; Rusk, Rosemary A; Hicks, Shannon E; Sahn, David J

2002-10-01

Our study was intended to test the accuracy of a 3-dimensional (3D) digital color Doppler flow convergence (FC) method for assessing the effective orifice area (EOA) in a new dynamic orifice model mimicking a variety of mitral regurgitation. FC surface area methods for detecting EOA have been reported to be useful for quantifying the severity of valvular regurgitation. With our new 3D digital direct FC method, all raw velocity data are available and variable Nyquist limits can be selected for computation of direct FC surface area for computing instantaneous flow rate and temporal change of EOA. A 7.0-MHz multiplane transesophageal probe from an ultrasound system (ATL HDI 5000) was linked and controlled by a computer workstation to provide 3D images. Three differently shaped latex orifices (zigzag, arc, and straight slit, each with cutting-edge length of 1 cm) were used to mimic the dynamic orifice of mitral regurgitation. 3D FC surface computation was performed on parallel slices through the 3D data set at aliasing velocities (14-48 cm/s) selected to maximize the regularity and minimize lateral dropout of the visualized 3D FC at 5 points per cardiac cycle. Using continuous wave velocity for each, 3D-calculated EOA was compared with EOA determined by using continuous wave Doppler and the flow rate from a reference ultrasonic flow meter. Simultaneous digital video images were also recorded to define the actual orifice size for 9 stroke volumes (15-55 mL/beat with maximum flow rates 45-182 mL/s). Over the 9 pulsatile flow states and 3 orifices, 3D FC EOAs (0.05-0.63 cm(2)) from different phases of the cardiac cycle in each pump setting correlated well with reference EOA (r = 0.89-0.92, SEE = 0.027-0.055cm(2)) and they also correlated well with digital video images of the actual orifice peak (r = 0.97-0.98, SEE = 0.016-0.019 cm(2)), although they were consistently smaller, as expected by the contraction coefficient. The digital 3D FC method can accurately predict flow rate, and, thus, EOA (in conjunction with continuous wave Doppler), because it allows direct FC surface measurement despite temporal variability of FC shape.

THREE-DIMENSIONAL MODELING OF THE DYNAMICS OF THERAPEUTIC ULTRASOUND CONTRAST AGENTS

PubMed Central

Hsiao, Chao-Tsung; Lu, Xiaozhen; Chahine, Georges

2010-01-01

A 3-D thick-shell contrast agent dynamics model was developed by coupling a finite volume Navier-Stokes solver and a potential boundary element method flow solver to simulate the dynamics of thick-shelled contrast agents subjected to pressure waves. The 3-D model was validated using a spherical thick-shell model validated by experimental observations. We then used this model to study shell break-up during nonspherical deformations resulting from multiple contrast agent interaction or the presence of a nearby solid wall. Our simulations indicate that the thick viscous shell resists the contrast agent from forming a re-entrant jet, as normally observed for an air bubble oscillating near a solid wall. Instead, the shell thickness varies significantly from location to location during the dynamics, and this could lead to shell break-up caused by local shell thinning and stretching. PMID:20950929

Development of a Reduced-Order Three-Dimensional Flow Model for Thermal Mixing and Stratification Simulation during Reactor Transients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Rui

2017-09-03

Mixing, thermal-stratification, and mass transport phenomena in large pools or enclosures play major roles for the safety of reactor systems. Depending on the fidelity requirement and computational resources, various modeling methods, from the 0-D perfect mixing model to 3-D Computational Fluid Dynamics (CFD) models, are available. Each is associated with its own advantages and shortcomings. It is very desirable to develop an advanced and efficient thermal mixing and stratification modeling capability embedded in a modern system analysis code to improve the accuracy of reactor safety analyses and to reduce modeling uncertainties. An advanced system analysis tool, SAM, is being developedmore » at Argonne National Laboratory for advanced non-LWR reactor safety analysis. While SAM is being developed as a system-level modeling and simulation tool, a reduced-order three-dimensional module is under development to model the multi-dimensional flow and thermal mixing and stratification in large enclosures of reactor systems. This paper provides an overview of the three-dimensional finite element flow model in SAM, including the governing equations, stabilization scheme, and solution methods. Additionally, several verification and validation tests are presented, including lid-driven cavity flow, natural convection inside a cavity, laminar flow in a channel of parallel plates. Based on the comparisons with the analytical solutions and experimental results, it is demonstrated that the developed 3-D fluid model can perform very well for a wide range of flow problems.« less

The moving confluence route technology with WAD scheme for 3D hydrodynamic simulation in high altitude inland waters

NASA Astrophysics Data System (ADS)

Wang, Yonggui; Yang, Yinqun; Chen, Xiaolong; Engel, Bernard A.; Zhang, Wanshun

2018-04-01

For three-dimensional hydrodynamic simulations in inland waters, the rapid changes with moving boundary and various input conditions should be considered. Some models are developed with moving boundary but the dynamic change of discharges is unresolved or ignored. For better hydrodynamic simulation in inland waters, the widely used 3D model, ECOMSED, has been improved by moving confluence route (MCR) method with a wetting and drying scheme (WAD). The fixed locations of water and pollutants inputs from tributaries, point sources and non-point sources have been changed to dynamic confluence routes as the boundary moving. The improved model was applied in an inland water area, Qingshuihai reservoir, Kunming City, China, for a one-year hydrodynamic simulation. The results were verified by water level, flow velocity and water mass conservation. Detailed water level variation analysis and velocity field comparison at different times showed that the improved model has better performance for simulating the boundary moving phenomenon and moving discharges along with water level changing than the original one. The improved three-dimensional model is available for hydrodynamics simulation in water bodies where water boundary shifts along with change of water level and have various inlets.

Single-camera three-dimensional tracking of natural particulate and zooplankton

NASA Astrophysics Data System (ADS)

Troutman, Valerie A.; Dabiri, John O.

2018-07-01

We develop and characterize an image processing algorithm to adapt single-camera defocusing digital particle image velocimetry (DDPIV) for three-dimensional (3D) particle tracking velocimetry (PTV) of natural particulates, such as those present in the ocean. The conventional DDPIV technique is extended to facilitate tracking of non-uniform, non-spherical particles within a volume depth an order of magnitude larger than current single-camera applications (i.e. 10 cm  ×  10 cm  ×  24 cm depth) by a dynamic template matching method. This 2D cross-correlation method does not rely on precise determination of the centroid of the tracked objects. To accommodate the broad range of particle number densities found in natural marine environments, the performance of the measurement technique at higher particle densities has been improved by utilizing the time-history of tracked objects to inform 3D reconstruction. The developed processing algorithms were analyzed using synthetically generated images of flow induced by Hill’s spherical vortex, and the capabilities of the measurement technique were demonstrated empirically through volumetric reconstructions of the 3D trajectories of particles and highly non-spherical, 5 mm zooplankton.

Three-dimensional simulation of beam propagation and heat transfer in static gas Cs DPALs using wave optics and fluid dynamics models

NASA Astrophysics Data System (ADS)

Waichman, Karol; Barmashenko, Boris D.; Rosenwaks, Salman

2017-10-01

Analysis of beam propagation, kinetic and fluid dynamic processes in Cs diode pumped alkali lasers (DPALs), using wave optics model and gasdynamic code, is reported. The analysis is based on a three-dimensional, time-dependent computational fluid dynamics (3D CFD) model. The Navier-Stokes equations for momentum, heat and mass transfer are solved by a commercial Ansys FLUENT solver based on the finite volume discretization technique. The CFD code which solves the gas conservation equations includes effects of natural convection and temperature diffusion of the species in the DPAL mixture. The DPAL kinetic processes in the Cs/He/C2H6 gas mixture dealt with in this paper involve the three lowest energy levels of Cs, (1) 62S1/2, (2) 62P1/2 and (3) 62P3/2. The kinetic processes include absorption due to the 1->3 D2 transition followed by relaxation the 3 to 2 fine structure levels and stimulated emission due to the 2->1 D1 transition. Collisional quenching of levels 2 and 3 and spontaneous emission from these levels are also considered. The gas flow conservation equations are coupled to fast-Fourier-transform algorithm for transverse mode propagation to obtain a solution of the scalar paraxial propagation equation for the laser beam. The wave propagation equation is solved by the split-step beam propagation method where the gain and refractive index in the DPAL medium affect the wave amplitude and phase. Using the CFD and beam propagation models, the gas flow pattern and spatial distributions of the pump and laser intensities in the resonator were calculated for end-pumped Cs DPAL. The laser power, DPAL medium temperature and the laser beam quality were calculated as a function of pump power. The results of the theoretical model for laser power were compared to experimental results of Cs DPAL.

Generic Hypersonic Inlet Module Analysis

NASA Technical Reports Server (NTRS)

Cockrell, Chares E., Jr.; Huebner, Lawrence D.

2004-01-01

A computational study associated with an internal inlet drag analysis was performed for a generic hypersonic inlet module. The purpose of this study was to determine the feasibility of computing the internal drag force for a generic scramjet engine module using computational methods. The computational study consisted of obtaining two-dimensional (2D) and three-dimensional (3D) computational fluid dynamics (CFD) solutions using the Euler and parabolized Navier-Stokes (PNS) equations. The solution accuracy was assessed by comparisons with experimental pitot pressure data. The CFD analysis indicates that the 3D PNS solutions show the best agreement with experimental pitot pressure data. The internal inlet drag analysis consisted of obtaining drag force predictions based on experimental data and 3D CFD solutions. A comparative assessment of each of the drag prediction methods is made and the sensitivity of CFD drag values to computational procedures is documented. The analysis indicates that the CFD drag predictions are highly sensitive to the computational procedure used.

The limits of hamiltonian structures in three-dimensional elasticity, shells, and rods

NASA Astrophysics Data System (ADS)

Ge, Z.; Kruse, H. P.; Marsden, J. E.

1996-01-01

This paper uses Hamiltonian structures to study the problem of the limit of three-dimensional (3D) elastic models to shell and rod models. In the case of shells, we show that the Hamiltonian structure for a three-dimensional elastic body converges, in a sense made precise, to that for a shell model described by a one-director Cosserat surface as the thickness goes to zero. We study limiting procedures that give rise to unconstrained as well as constrained Cosserat director models. The case of a rod is also considered and similar convergence results are established, with the limiting model being a geometrically exact director rod model (in the framework developed by Antman, Simo, and coworkers). The resulting model may or may not have constraints, depending on the nature of the constitutive relations and their behavior under the limiting procedure. The closeness of Hamiltonian structures is measured by the closeness of Poisson brackets on certain classes of functions, as well as the Hamiltonians. This provides one way of justifying the dynamic one-director model for shells. Another way of stating the convergence result is that there is an almost-Poisson embedding from the phase space of the shell to the phase space of the 3D elastic body, which implies that, in the sense of Hamiltonian structures, the dynamics of the elastic body is close to that of the shell. The constitutive equations of the 3D model and their behavior as the thickness tends to zero dictates whether the limiting 2D model is a constrained or an unconstrained director model. We apply our theory in the specific case of a 3D Saint Venant-Kirchhoff material and derive the corresponding limiting shell and rod theories. The limiting shell model is an interesting Kirchhoff-like shell model in which the stored energy function is explicitly derived in terms of the shell curvature. For rods, one gets (with an additional inextensibility constraint) a one-director Kirchhoff elastic rod model, which reduces to the well-known Euler elastica if one adds an additional single constraint that the director lines up with the Frenet frame.

Nonlinear complexity behaviors of agent-based 3D Potts financial dynamics with random environments

NASA Astrophysics Data System (ADS)

Xing, Yani; Wang, Jun

2018-02-01

A new microscopic 3D Potts interaction financial price model is established in this work, to investigate the nonlinear complexity behaviors of stock markets. 3D Potts model, which extends the 2D Potts model to three-dimensional, is a cubic lattice model to explain the interaction behavior among the agents. In order to explore the complexity of real financial markets and the 3D Potts financial model, a new random coarse-grained Lempel-Ziv complexity is proposed to certain series, such as the price returns, the price volatilities, and the random time d-returns. Then the composite multiscale entropy (CMSE) method is applied to the intrinsic mode functions (IMFs) and the corresponding shuffled data to study the complexity behaviors. The empirical results indicate that the 3D financial model is feasible.

Effects of aeration on matrix temperature by infrared thermal imager and computational fluid dynamics during sludge bio-drying.

PubMed

Yu, Dawei; Yang, Min; Qi, Lu; Liu, Mengmeng; Wang, Yawei; Wei, Yuansong

2017-10-01

The effect of aeration on the pile matrix temperature was investigated using thermocouples and Infrared Thermal Imager (IRI) for temperature sensing, and Computational Fluid Dynamics (CFD) for modelling of temperature variation during aeration in a full-scale sludge biodrying plant. With aeration saving of 20%, the improved strategy speeded up biodrying from 21 days to 14 days, while achieving similar drying effect. A persistent thermocouple recorded the one-dimensional (1D) total temperature variation of all aeration strategies. The IRI captured the rapid two-dimensional (2D) pile temperature dropped from 72.5 °C to 30.3 °C during 6 min of aeration, which mechanism suggested as the latent heat of moisture evaporation and sensible heat of air exchange. The CFD three-dimensional (3D) CFD results highlight the importance of latent heat rather than sensible heat. Therefore, the pile temperature drop inferred is ΔT = 5.38 °C theoretically and ΔT = 5.17 ± 4.56 °C practically, per unit of MC removed. These findings also emphasize the possibility of a pile temperature valley, due to excessive aeration under unsaturated vapour conditions. Surface temperature monitored by IRI coupled with 3D temperature simulated by CFD rapidly gives a clear matrix temperature evolution, empowering biodrying by more accurate temperature and aeration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Color Constancy in Two-Dimensional and Three-Dimensional Scenes: Effects of Viewing Methods and Surface Texture

PubMed Central

Morimoto, Takuma; Mizokami, Yoko; Yaguchi, Hirohisa; Buck, Steven L.

2017-01-01

There has been debate about how and why color constancy may be better in three-dimensional (3-D) scenes than in two-dimensional (2-D) scenes. Although some studies have shown better color constancy for 3-D conditions, the role of specific cues remains unclear. In this study, we compared color constancy for a 3-D miniature room (a real scene consisting of actual objects) and 2-D still images of that room presented on a monitor using three viewing methods: binocular viewing, monocular viewing, and head movement. We found that color constancy was better for the 3-D room; however, color constancy for the 2-D image improved when the viewing method caused the scene to be perceived more like a 3-D scene. Separate measurements of the perceptual 3-D effect of each viewing method also supported these results. An additional experiment comparing a miniature room and its image with and without texture suggested that surface texture of scene objects contributes to color constancy. PMID:29238513

Three-dimensional (3-D) model utilization for fracture reconstruction in oral and maxillofacial surgery: A case report

NASA Astrophysics Data System (ADS)

Damayanti, Ista; Lilies, Latief, Benny S.

2017-02-01

Three-dimensional (3-D) printing has been identified as an innovative manufacturing technology of functional parts. The 3-D model was produced based on CT-Scan using Osyrix software, where automatic segmentation was performed and convert into STL format. This STL format was then ready to be produced physically, layer-by-layer to create 3-D model.

Application of ground-penetrating radar imagery for three-dimensional visualisation of near-surface structures in ice-rich permafrost, Barrow, Alaska

USGS Publications Warehouse

Munroe, Jeffrey S.; Doolittle, James A.; Kanevskiy, Mikhail; Hinkel, Kenneth M.; Nelson, Frederick E.; Jones, Benjamin M.; Shur, Yuri; Kimble, John M.

2007-01-01

Three-dimensional ground-penetrating radar (3D GPR) was used to investigate the subsurface structure of ice-wedge polygons and other features of the frozen active layer and near-surface permafrost near Barrow, Alaska. Surveys were conducted at three sites located on landscapes of different geomorphic age. At each site, sediment cores were collected and characterised to aid interpretation of GPR data. At two sites, 3D GPR was able to delineate subsurface ice-wedge networks with high fidelity. Three-dimensional GPR data also revealed a fundamental difference in ice-wedge morphology between these two sites that is consistent with differences in landscape age. At a third site, the combination of two-dimensional and 3D GPR revealed the location of an active frost boil with ataxitic cryostructure. When supplemented by analysis of soil cores, 3D GPR offers considerable potential for imaging, interpreting and 3D mapping of near-surface soil and ice structures in permafrost environments.

The 3D Navier-Stokes analysis of a Mach 2.68 bifurcated rectangular mixed-compression inlet

NASA Technical Reports Server (NTRS)

Mizukami, M.; Saunders, J. D.

1995-01-01

The supersonic diffuser of a Mach 2.68 bifurcated, rectangular, mixed-compression inlet was analyzed using a three-dimensional (3D) Navier-Stokes flow solver. A two-equation turbulence model, and a porous bleed model based on unchoked bleed hole discharge coefficients were used. Comparisons were made with experimental data, inviscid theory, and two-dimensional Navier-Stokes analyses. The main objective was to gain insight into the inlet fluid dynamics. Examination of the computational results along with the experimental data suggest that the cowl shock-sidewall boundary layer interaction near the leading edge caused a substantial separation in the wind tunnel inlet model. As a result, the inlet performance may have been compromised by increased spillage and higher bleed mass flow requirements. The internal flow contained substantial waves that were not in the original inviscid design. 3D effects were fairly minor for this inlet at on-design conditions. Navier-Stokes analysis appears to be an useful tool for gaining insight into the inlet fluid dynamics. It provides a higher fidelity simulation of the flowfield than the original inviscid design, by taking into account boundary layers, porous bleed, and their interactions with shock waves.

Heat Shock Protein Genes Undergo Dynamic Alteration in Their Three-Dimensional Structure and Genome Organization in Response to Thermal Stress

PubMed Central

Chowdhary, Surabhi; Kainth, Amoldeep S.

2017-01-01

ABSTRACT Three-dimensional (3D) chromatin organization is important for proper gene regulation, yet how the genome is remodeled in response to stress is largely unknown. Here, we use a highly sensitive version of chromosome conformation capture in combination with fluorescence microscopy to investigate Heat Shock Protein (HSP) gene conformation and 3D nuclear organization in budding yeast. In response to acute thermal stress, HSP genes undergo intense intragenic folding interactions that go well beyond 5′-3′ gene looping previously described for RNA polymerase II genes. These interactions include looping between upstream activation sequence (UAS) and promoter elements, promoter and terminator regions, and regulatory and coding regions (gene “crumpling”). They are also dynamic, being prominent within 60 s, peaking within 2.5 min, and attenuating within 30 min, and correlate with HSP gene transcriptional activity. With similarly striking kinetics, activated HSP genes, both chromosomally linked and unlinked, coalesce into discrete intranuclear foci. Constitutively transcribed genes also loop and crumple yet fail to coalesce. Notably, a missense mutation in transcription factor TFIIB suppresses gene looping, yet neither crumpling nor HSP gene coalescence is affected. An inactivating promoter mutation, in contrast, obviates all three. Our results provide evidence for widespread, transcription-associated gene crumpling and demonstrate the de novo assembly and disassembly of HSP gene foci. PMID:28970326

Heat Shock Protein Genes Undergo Dynamic Alteration in Their Three-Dimensional Structure and Genome Organization in Response to Thermal Stress.

PubMed

Chowdhary, Surabhi; Kainth, Amoldeep S; Gross, David S

2017-12-15

Three-dimensional (3D) chromatin organization is important for proper gene regulation, yet how the genome is remodeled in response to stress is largely unknown. Here, we use a highly sensitive version of chromosome conformation capture in combination with fluorescence microscopy to investigate Heat Shock Protein ( HSP ) gene conformation and 3D nuclear organization in budding yeast. In response to acute thermal stress, HSP genes undergo intense intragenic folding interactions that go well beyond 5'-3' gene looping previously described for RNA polymerase II genes. These interactions include looping between upstream activation sequence (UAS) and promoter elements, promoter and terminator regions, and regulatory and coding regions (gene "crumpling"). They are also dynamic, being prominent within 60 s, peaking within 2.5 min, and attenuating within 30 min, and correlate with HSP gene transcriptional activity. With similarly striking kinetics, activated HSP genes, both chromosomally linked and unlinked, coalesce into discrete intranuclear foci. Constitutively transcribed genes also loop and crumple yet fail to coalesce. Notably, a missense mutation in transcription factor TFIIB suppresses gene looping, yet neither crumpling nor HSP gene coalescence is affected. An inactivating promoter mutation, in contrast, obviates all three. Our results provide evidence for widespread, transcription-associated gene crumpling and demonstrate the de novo assembly and disassembly of HSP gene foci. Copyright © 2017 American Society for Microbiology.

Development of Three-Dimensional Completion of Complex Objects

ERIC Educational Resources Information Center

Soska, Kasey C.; Johnson, Scott P.

2013-01-01

Three-dimensional (3D) object completion, the ability to perceive the backs of objects seen from a single viewpoint, emerges at around 6 months of age. Yet, only relatively simple 3D objects have been used in assessing its development. This study examined infants' 3D object completion when presented with more complex stimuli. Infants…

Experimental Evidence for Improved Neuroimaging Interpretation Using Three-Dimensional Graphic Models

ERIC Educational Resources Information Center

Ruisoto, Pablo; Juanes, Juan Antonio; Contador, Israel; Mayoral, Paula; Prats-Galino, Alberto

2012-01-01

Three-dimensional (3D) or volumetric visualization is a useful resource for learning about the anatomy of the human brain. However, the effectiveness of 3D spatial visualization has not yet been assessed systematically. This report analyzes whether 3D volumetric visualization helps learners to identify and locate subcortical structures more…

GaN: From three- to two-dimensional single-layer crystal and its multilayer van der Waals solids

NASA Astrophysics Data System (ADS)

Onen, A.; Kecik, D.; Durgun, E.; Ciraci, S.

2016-02-01

Three-dimensional (3D) GaN is a III-V compound semiconductor with potential optoelectronic applications. In this paper, starting from 3D GaN in wurtzite and zinc-blende structures, we investigated the mechanical, electronic, and optical properties of the 2D single-layer honeycomb structure of GaN (g -GaN ) and its bilayer, trilayer, and multilayer van der Waals solids using density-functional theory. Based on high-temperature ab initio molecular-dynamics calculations, we first showed that g -GaN can remain stable at high temperature. Then we performed a comparative study to reveal how the physical properties vary with dimensionality. While 3D GaN is a direct-band-gap semiconductor, g -GaN in two dimensions has a relatively wider indirect band gap. Moreover, 2D g -GaN displays a higher Poisson ratio and slightly less charge transfer from cation to anion. In two dimensions, the optical-absorption spectra of 3D crystalline phases are modified dramatically, and their absorption onset energy is blueshifted. We also showed that the physical properties predicted for freestanding g -GaN are preserved when g -GaN is grown on metallic as well as semiconducting substrates. In particular, 3D layered blue phosphorus, being nearly lattice-matched to g -GaN , is found to be an excellent substrate for growing g -GaN . Bilayer, trilayer, and van der Waals crystals can be constructed by a special stacking sequence of g -GaN , and they can display electronic and optical properties that can be controlled by the number of g -GaN layers. In particular, their fundamental band gap decreases and changes from indirect to direct with an increasing number of g -GaN layers.

3D printing of bacteria into functional complex materials.

PubMed

Schaffner, Manuel; Rühs, Patrick A; Coulter, Fergal; Kilcher, Samuel; Studart, André R

2017-12-01

Despite recent advances to control the spatial composition and dynamic functionalities of bacteria embedded in materials, bacterial localization into complex three-dimensional (3D) geometries remains a major challenge. We demonstrate a 3D printing approach to create bacteria-derived functional materials by combining the natural diverse metabolism of bacteria with the shape design freedom of additive manufacturing. To achieve this, we embedded bacteria in a biocompatible and functionalized 3D printing ink and printed two types of "living materials" capable of degrading pollutants and of producing medically relevant bacterial cellulose. With this versatile bacteria-printing platform, complex materials displaying spatially specific compositions, geometry, and properties not accessed by standard technologies can be assembled from bottom up for new biotechnological and biomedical applications.

Extended capability of the integrated transport analysis suite, TASK3D-a, for LHD experiment

NASA Astrophysics Data System (ADS)

Yokoyama, M.; Seki, R.; Suzuki, C.; Sato, M.; Emoto, M.; Murakami, S.; Osakabe, M.; Tsujimura, T. Ii.; Yoshimura, Y.; Ido, T.; Ogawa, K.; Satake, S.; Suzuki, Y.; Goto, T.; Ida, K.; Pablant, N.; Gates, D.; Warmer, F.; Vincenzi, P.; Simulation Reactor Research Project, Numerical; LHD Experiment Group

2017-12-01

The integrated transport analysis suite, TASK3D-a (Analysis), has been developed to be capable for routine whole-discharge analyses of plasmas confined in three-dimensional (3D) magnetic configurations such as the LHD. The routine dynamic energy balance analysis for NBI-heated plasmas was made possible in the first version released in September 2012. The suite has been further extended through implementing additional modules for neoclassical transport and ECH deposition for 3D configurations. A module has also been added for creating systematic data for the International Stellarator-Heliotron Confinement and Profile Database. Improvement of neutral beam injection modules for multiple-ion species plasmas and loose coupling with a large-simulation code are also highlights of recent developments.

3D printing of bacteria into functional complex materials

PubMed Central

Schaffner, Manuel; Rühs, Patrick A.; Coulter, Fergal; Kilcher, Samuel; Studart, André R.

2017-01-01

Despite recent advances to control the spatial composition and dynamic functionalities of bacteria embedded in materials, bacterial localization into complex three-dimensional (3D) geometries remains a major challenge. We demonstrate a 3D printing approach to create bacteria-derived functional materials by combining the natural diverse metabolism of bacteria with the shape design freedom of additive manufacturing. To achieve this, we embedded bacteria in a biocompatible and functionalized 3D printing ink and printed two types of “living materials” capable of degrading pollutants and of producing medically relevant bacterial cellulose. With this versatile bacteria-printing platform, complex materials displaying spatially specific compositions, geometry, and properties not accessed by standard technologies can be assembled from bottom up for new biotechnological and biomedical applications. PMID:29214219

3D Feature Extraction for Unstructured Grids

NASA Technical Reports Server (NTRS)

Silver, Deborah

1996-01-01

Visualization techniques provide tools that help scientists identify observed phenomena in scientific simulation. To be useful, these tools must allow the user to extract regions, classify and visualize them, abstract them for simplified representations, and track their evolution. Object Segmentation provides a technique to extract and quantify regions of interest within these massive datasets. This article explores basic algorithms to extract coherent amorphous regions from two-dimensional and three-dimensional scalar unstructured grids. The techniques are applied to datasets from Computational Fluid Dynamics and those from Finite Element Analysis.

Matrix-Assisted Three-Dimensional Printing of Cellulose Nanofibers for Paper Microfluidics.

PubMed

Shin, Sungchul; Hyun, Jinho

2017-08-09

A cellulose nanofiber (CNF), one of the most attractive green bioresources, was adopted for construction of microfluidic devices using matrix-assisted three-dimensional (3D) printing. CNF hydrogels can support structures printed using CAD design in a 3D hydrogel environment with the appropriate combination of rheological properties between the CNF hydrogel and ink materials. Amazingly, the structure printed freely in the bulky CNF hydrogels was able to retain its highly resolved 3D features in an ultrathin two-dimensional (2D) paper using a simple drying process. The dimensional change in the CNF hydrogels from 3D to 2D resulted from simple dehydration of the CNFs and provided transparent, stackable paper-based 3D channel devices. As a proof of principle, the rheological properties of the CNF hydrogels, the 3D structure of the ink, the formation of channels by evacuation of the ink, and the highly localized selectivity of the devices are described.

Design of a rotational three-dimensional nonimaging device by a compensated two-dimensional design process.

PubMed

Yang, Yi; Qian, Ke-Yuan; Luo, Yi

2006-07-20

A compensation process has been developed to design rotational three-dimensional (3D) nonimaging devices. By compensating the desired light distribution during a two-dimensional (2D) design process for an extended Lambertian source using a compensation coefficient, the meridian plane of a 3D device with good performance can be obtained. This method is suitable in many cases with fast calculation speed. Solutions to two kinds of optical design problems have been proposed, and the limitation of this compensated 2D design method is discussed.

A Dynamic Three-Dimensional Network Visualization Program for Integration into CyberCIEGE and Other Network Visualization Scenarios

DTIC Science & Technology

2007-06-01

information flow involved in network attacks. This kind of information can be invaluable in learning how to best setup and defend computer networks...administrators, and those interested in learning about securing networks a way to conceptualize this complex system of computing. NTAV3D will provide a three...teaching with visual and other components can make learning more effective” (Baxley et al, 2006). A hyperbox (Alpern and Carter, 1991) is

Phase Diagrams of Three-Dimensional Anderson and Quantum Percolation Models Using Deep Three-Dimensional Convolutional Neural Network

NASA Astrophysics Data System (ADS)

Mano, Tomohiro; Ohtsuki, Tomi

2017-11-01

The three-dimensional Anderson model is a well-studied model of disordered electron systems that shows the delocalization-localization transition. As in our previous papers on two- and three-dimensional (2D, 3D) quantum phase transitions [J. Phys. Soc. Jpn. 85, 123706 (2016), 86, 044708 (2017)], we used an image recognition algorithm based on a multilayered convolutional neural network. However, in contrast to previous papers in which 2D image recognition was used, we applied 3D image recognition to analyze entire 3D wave functions. We show that a full phase diagram of the disorder-energy plane is obtained once the 3D convolutional neural network has been trained at the band center. We further demonstrate that the full phase diagram for 3D quantum bond and site percolations can be drawn by training the 3D Anderson model at the band center.

Ultrafast energy- and momentum-resolved dynamics of magnetic correlations in the photo-doped Mott insulator Sr2IrO4.

PubMed

Dean, M P M; Cao, Y; Liu, X; Wall, S; Zhu, D; Mankowsky, R; Thampy, V; Chen, X M; Vale, J G; Casa, D; Kim, Jungho; Said, A H; Juhas, P; Alonso-Mori, R; Glownia, J M; Robert, A; Robinson, J; Sikorski, M; Song, S; Kozina, M; Lemke, H; Patthey, L; Owada, S; Katayama, T; Yabashi, M; Tanaka, Yoshikazu; Togashi, T; Liu, J; Rayan Serrao, C; Kim, B J; Huber, L; Chang, C-L; McMorrow, D F; Först, M; Hill, J P

2016-06-01

Measuring how the magnetic correlations evolve in doped Mott insulators has greatly improved our understanding of the pseudogap, non-Fermi liquids and high-temperature superconductivity. Recently, photo-excitation has been used to induce similarly exotic states transiently. However, the lack of available probes of magnetic correlations in the time domain hinders our understanding of these photo-induced states and how they could be controlled. Here, we implement magnetic resonant inelastic X-ray scattering at a free-electron laser to directly determine the magnetic dynamics after photo-doping the Mott insulator Sr2IrO4. We find that the non-equilibrium state, 2 ps after the excitation, exhibits strongly suppressed long-range magnetic order, but hosts photo-carriers that induce strong, non-thermal magnetic correlations. These two-dimensional (2D) in-plane Néel correlations recover within a few picoseconds, whereas the three-dimensional (3D) long-range magnetic order restores on a fluence-dependent timescale of a few hundred picoseconds. The marked difference in these two timescales implies that the dimensionality of magnetic correlations is vital for our understanding of ultrafast magnetic dynamics.

Observation of three-dimensional internal structure of steel materials by means of serial sectioning with ultrasonic elliptical vibration cutting.

PubMed

Fujisaki, K; Yokota, H; Nakatsuchi, H; Yamagata, Y; Nishikawa, T; Udagawa, T; Makinouchi, A

2010-01-01

A three-dimensional (3D) internal structure observation system based on serial sectioning was developed from an ultrasonic elliptical vibration cutting device and an optical microscope combined with a high-precision positioning device. For bearing steel samples, the cutting device created mirrored surfaces suitable for optical metallography, even for long-cutting distances during serial sectioning of these ferrous materials. Serial sectioning progressed automatically by means of numerical control. The system was used to observe inclusions in steel materials on a scale of several tens of micrometers. Three specimens containing inclusions were prepared from bearing steels. These inclusions could be detected as two-dimensional (2D) sectional images with resolution better than 1 mum. A three-dimensional (3D) model of each inclusion was reconstructed from the 2D serial images. The microscopic 3D models had sharp edges and complicated surfaces.

Three-dimensional graphene foam as a biocompatible and conductive scaffold for neural stem cells

PubMed Central

Li, Ning; Zhang, Qi; Gao, Song; Song, Qin; Huang, Rong; Wang, Long; Liu, Liwei; Dai, Jianwu; Tang, Mingliang; Cheng, Guosheng

2013-01-01

Neural stem cell (NSC) based therapy provides a promising approach for neural regeneration. For the success of NSC clinical application, a scaffold is required to provide three-dimensional (3D) cell growth microenvironments and appropriate synergistic cell guidance cues. Here, we report the first utilization of graphene foam, a 3D porous structure, as a novel scaffold for NSCs in vitro. It was found that three-dimensional graphene foams (3D-GFs) can not only support NSC growth, but also keep cell at an active proliferation state with upregulation of Ki67 expression than that of two-dimensional graphene films. Meanwhile, phenotypic analysis indicated that 3D-GFs can enhance the NSC differentiation towards astrocytes and especially neurons. Furthermore, a good electrical coupling of 3D-GFs with differentiated NSCs for efficient electrical stimulation was observed. Our findings implicate 3D-GFs could offer a powerful platform for NSC research, neural tissue engineering and neural prostheses. PMID:23549373

Cortical dynamics of three-dimensional figure-ground perception of two-dimensional pictures.

PubMed

Grossberg, S

1997-07-01

This article develops the FACADE theory of 3-dimensional (3-D) vision and figure-ground separation to explain data concerning how 2-dimensional pictures give rise to 3-D percepts of occluding and occluded objects. The model describes how geometrical and contrastive properties of a picture can either cooperate or compete when forming the boundaries and surface representation that subserve conscious percepts. Spatially long-range cooperation and spatially short-range competition work together to separate the boundaries of occluding figures from their occluded neighbors. This boundary ownership process is sensitive to image T junctions at which occluded figures contact occluding figures. These boundaries control the filling-in of color within multiple depth-sensitive surface representations. Feedback between surface and boundary representations strengthens consistent boundaries while inhibiting inconsistent ones. Both the boundary and the surface representations of occluded objects may be amodally completed, while the surface representations of unoccluded objects become visible through modal completion. Functional roles for conscious modal and amodal representations in object recognition, spatial attention, and reaching behaviors are discussed. Model interactions are interpreted in terms of visual, temporal, and parietal cortices.

Computational fluid dynamics (CFD) study on the fetal aortic coarctation

NASA Astrophysics Data System (ADS)

Zhou, Yue; Zhang, Yutao; Wang, Jingying

2018-03-01

Blood flows in normal and coarctate fetal aortas are simulated by the CFD technique using T-rex grids. The three-dimensional (3-D) digital model of the fetal arota is reconstructed by the computer-aided design (CAD) software based on two-dimensional (2-D) ultrasono tomographic images. Simulation results displays the development and enhancement of the secondary flow structure in the coarctate fetal arota. As the diameter narrow ratio rises greater than 45%, the pressure and wall shear stress (WSS) of the aorta arch increase exponentially, which is consistent with the conventional clinical concept. The present study also demonstrates that CFD is a very promising assistant technique to investigate human cardiovascular diseases.

A low-cost microwell device for high-resolution imaging of neurite outgrowth in 3D

NASA Astrophysics Data System (ADS)

Ren, Yuan; Mlodzianoski, Michael J.; Cheun Lee, Aih; Huang, Fang; Suter, Daniel M.

2018-06-01

Objective. Current neuronal cell culture is mostly performed on two-dimensional (2D) surfaces, which lack many of the important features of the native environment of neurons, including topographical cues, deformable extracellular matrix, and spatial isotropy or anisotropy in three dimensions. Although three-dimensional (3D) cell culture systems provide a more physiologically relevant environment than 2D systems, their popularity is greatly hampered by the lack of easy-to-make-and-use devices. We aim to develop a widely applicable 3D culture procedure to facilitate the transition of neuronal cultures from 2D to 3D. Approach. We made a simple microwell device for 3D neuronal cell culture that is inexpensive, easy to assemble, and fully compatible with commonly used imaging techniques, including super-resolution microscopy. Main results. We developed a novel gel mixture to support 3D neurite regeneration of Aplysia bag cell neurons, a system that has been extensively used for quantitative analysis of growth cone dynamics in 2D. We found that the morphology and growth pattern of bag cell growth cones in 3D culture closely resemble the ones of growth cones observed in vivo. We demonstrated the capability of our device for high-resolution imaging of cytoskeletal and signaling proteins as well as organelles. Significance. Neuronal cell culture has been a valuable tool for neuroscientists to study the behavior of neurons in a controlled environment. Compared to 2D, neurons cultured in 3D retain the majority of their native characteristics, while offering higher accessibility, control, and repeatability. We expect that our microwell device will facilitate a wider adoption of 3D neuronal cultures to study the mechanisms of neurite regeneration.

NEUTRINO-DRIVEN TURBULENT CONVECTION AND STANDING ACCRETION SHOCK INSTABILITY IN THREE-DIMENSIONAL CORE-COLLAPSE SUPERNOVAE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdikamalov, Ernazar; Ott, Christian D.; Radice, David

2015-07-20

We conduct a series of numerical experiments into the nature of three-dimensional (3D) hydrodynamics in the postbounce stalled-shock phase of core-collapse supernovae using 3D general-relativistic hydrodynamic simulations of a 27 M{sub ⊙} progenitor star with a neutrino leakage/heating scheme. We vary the strength of neutrino heating and find three cases of 3D dynamics: (1) neutrino-driven convection, (2) initially neutrino-driven convection and subsequent development of the standing accretion shock instability (SASI), and (3) SASI-dominated evolution. This confirms previous 3D results of Hanke et al. and Couch and Connor. We carry out simulations with resolutions differing by up to a factor ofmore » ∼4 and demonstrate that low resolution is artificially favorable for explosion in the 3D convection-dominated case since it decreases the efficiency of energy transport to small scales. Low resolution results in higher radial convective fluxes of energy and enthalpy, more fully buoyant mass, and stronger neutrino heating. In the SASI-dominated case, lower resolution damps SASI oscillations. In the convection-dominated case, a quasi-stationary angular kinetic energy spectrum E(ℓ) develops in the heating layer. Like other 3D studies, we find E(ℓ) ∝ℓ{sup −1} in the “inertial range,” while theory and local simulations argue for E(ℓ) ∝ ℓ{sup −5/3}. We argue that current 3D simulations do not resolve the inertial range of turbulence and are affected by numerical viscosity up to the energy-containing scale, creating a “bottleneck” that prevents an efficient turbulent cascade.« less

Who Needs 3D When the Universe Is Flat?

ERIC Educational Resources Information Center

Eriksson, Urban; Linder, Cedric; Airey, John; Redfors, Andreas

2014-01-01

An overlooked feature in astronomy education is the need for students to learn to extrapolate three-dimensionality and the challenges that this may involve. Discerning critical features in the night sky that are embedded in dimensionality is a long-term learning process. Several articles have addressed the usefulness of three-dimensional (3D)…

Modeling and simulation of three dimensional manipulations of biological micro/nanoparticles by applying cylindrical contact mechanics models by means of AFM

NASA Astrophysics Data System (ADS)

Korayem, M. H.; Saraee, M. B.; Mahmoodi, Z.; Dehghani, S.

2015-11-01

This paper has attempted to investigate the effective forces in 3D manipulation of biological micro/nano particles. Most of the recent researches have only examined 2D spherical geometries but in this paper, the cylindrical geometries, which are much closer to the real geometries, were considered. For achieving a more accurate modeling, manipulation dynamics was also considered to be three dimensional which have been done for the first time. Because of the sensibility to the amount of endurable applied forces, manipulation process of biological micro/nano particles has some restrictions. Therefore, applied forces exerted on the particles in all different directions were simulated in order to restrict all those possible damages cause by operator of the AFM. Those data from simulated forces will bring a more accurate and sensible understanding for the operator to operate. For the validation of results, the proposed model was compared with the model presented for manipulation of gold nanoparticle and then, by reducing the effective parameters in the 3D manipulation, the results were compared with those obtained for the 2D cylindrical model and with the experimental results of spherical nanoparticle in the 2D manipulation.

Generalized three-dimensional lattice Boltzmann color-gradient method for immiscible two-phase pore-scale imbibition and drainage in porous media

NASA Astrophysics Data System (ADS)

Leclaire, Sébastien; Parmigiani, Andrea; Malaspinas, Orestis; Chopard, Bastien; Latt, Jonas

2017-03-01

This article presents a three-dimensional numerical framework for the simulation of fluid-fluid immiscible compounds in complex geometries, based on the multiple-relaxation-time lattice Boltzmann method to model the fluid dynamics and the color-gradient approach to model multicomponent flow interaction. New lattice weights for the lattices D3Q15, D3Q19, and D3Q27 that improve the Galilean invariance of the color-gradient model as well as for modeling the interfacial tension are derived and provided in the Appendix. The presented method proposes in particular an approach to model the interaction between the fluid compound and the solid, and to maintain a precise contact angle between the two-component interface and the wall. Contrarily to previous approaches proposed in the literature, this method yields accurate solutions even in complex geometries and does not suffer from numerical artifacts like nonphysical mass transfer along the solid wall, which is crucial for modeling imbibition-type problems. The article also proposes an approach to model inflow and outflow boundaries with the color-gradient method by generalizing the regularized boundary conditions. The numerical framework is first validated for three-dimensional (3D) stationary state (Jurin's law) and time-dependent (Washburn's law and capillary waves) problems. Then, the usefulness of the method for practical problems of pore-scale flow imbibition and drainage in porous media is demonstrated. Through the simulation of nonwetting displacement in two-dimensional random porous media networks, we show that the model properly reproduces three main invasion regimes (stable displacement, capillary fingering, and viscous fingering) as well as the saturating zone transition between these regimes. Finally, the ability to simulate immiscible two-component flow imbibition and drainage is validated, with excellent results, by numerical simulations in a Berea sandstone, a frequently used benchmark case used in this field, using a complex geometry that originates from a 3D scan of a porous sandstone. The methods presented in this article were implemented in the open-source PALABOS library, a general C++ matrix-based library well adapted for massive fluid flow parallel computation.

Three-dimensional bio-printing.

PubMed

Gu, Qi; Hao, Jie; Lu, YangJie; Wang, Liu; Wallace, Gordon G; Zhou, Qi

2015-05-01

Three-dimensional (3D) printing technology has been widely used in various manufacturing operations including automotive, defence and space industries. 3D printing has the advantages of personalization, flexibility and high resolution, and is therefore becoming increasingly visible in the high-tech fields. Three-dimensional bio-printing technology also holds promise for future use in medical applications. At present 3D bio-printing is mainly used for simulating and reconstructing some hard tissues or for preparing drug-delivery systems in the medical area. The fabrication of 3D structures with living cells and bioactive moieties spatially distributed throughout will be realisable. Fabrication of complex tissues and organs is still at the exploratory stage. This review summarize the development of 3D bio-printing and its potential in medical applications, as well as discussing the current challenges faced by 3D bio-printing.

Microstructurally Based Cross-slip Mechanisms and Their Effects on Dislocation Microstructure Evolution in fcc Crystals

DTIC Science & Technology

2015-01-01

still necessary. One such model that could bridge this gap is discrete dis- location dynamics ( DDD ) simulations, in which both the time- and length-scale...limitations from atomic simulations are greatly reduced. Over the past two decades, two-dimen- sional (2D) and three-dimensional (3D) DDD methods have...dislocation ensem- bles according to physics-based rules [27–34]. The physics that can be incorporated in DDD simulations can range http://dx.doi.org

RockFall analyst: A GIS extension for three-dimensional and spatially distributed rockfall hazard modeling

NASA Astrophysics Data System (ADS)

Lan, Hengxing; Derek Martin, C.; Lim, C. H.

2007-02-01

Geographic information system (GIS) modeling is used in combination with three-dimensional (3D) rockfall process modeling to assess rockfall hazards. A GIS extension, RockFall Analyst (RA), which is capable of effectively handling large amounts of geospatial information relative to rockfall behaviors, has been developed in ArcGIS using ArcObjects and C#. The 3D rockfall model considers dynamic processes on a cell plane basis. It uses inputs of distributed parameters in terms of raster and polygon features created in GIS. Two major components are included in RA: particle-based rockfall process modeling and geostatistics-based rockfall raster modeling. Rockfall process simulation results, 3D rockfall trajectories and their velocity features either for point seeders or polyline seeders are stored in 3D shape files. Distributed raster modeling, based on 3D rockfall trajectories and a spatial geostatistical technique, represents the distribution of spatial frequency, the flying and/or bouncing height, and the kinetic energy of falling rocks. A distribution of rockfall hazard can be created by taking these rockfall characteristics into account. A barrier analysis tool is also provided in RA to aid barrier design. An application of these modeling techniques to a case study is provided. The RA has been tested in ArcGIS 8.2, 8.3, 9.0 and 9.1.

Dynamic System Coupler Program (DYSCO 4.1). Volume 1. Theoretical Manual

DTIC Science & Technology

1989-01-01

present analysis is as follows: 1. Triplet X, Y, Z represents an inertia frame, R. The R system coordinates are the rotor shaft axes when there is...small perturbation analysis . 2.5 3-D MODAL STRUCTURE - CFM3 A three-dimensional structure is represented as a linear combination of orth­ ogonal modes...Include rotor blade damage modeling, Elgen analysis development, general time history solution development, frequency domain solution development

Massively parallel implementation of 3D-RISM calculation with volumetric 3D-FFT.

PubMed

Maruyama, Yutaka; Yoshida, Norio; Tadano, Hiroto; Takahashi, Daisuke; Sato, Mitsuhisa; Hirata, Fumio

2014-07-05

A new three-dimensional reference interaction site model (3D-RISM) program for massively parallel machines combined with the volumetric 3D fast Fourier transform (3D-FFT) was developed, and tested on the RIKEN K supercomputer. The ordinary parallel 3D-RISM program has a limitation on the number of parallelizations because of the limitations of the slab-type 3D-FFT. The volumetric 3D-FFT relieves this limitation drastically. We tested the 3D-RISM calculation on the large and fine calculation cell (2048(3) grid points) on 16,384 nodes, each having eight CPU cores. The new 3D-RISM program achieved excellent scalability to the parallelization, running on the RIKEN K supercomputer. As a benchmark application, we employed the program, combined with molecular dynamics simulation, to analyze the oligomerization process of chymotrypsin Inhibitor 2 mutant. The results demonstrate that the massive parallel 3D-RISM program is effective to analyze the hydration properties of the large biomolecular systems. Copyright © 2014 Wiley Periodicals, Inc.

Four-dimensional wavelet compression of arbitrarily sized echocardiographic data.

PubMed

Zeng, Li; Jansen, Christian P; Marsch, Stephan; Unser, Michael; Hunziker, Patrick R

2002-09-01

Wavelet-based methods have become most popular for the compression of two-dimensional medical images and sequences. The standard implementations consider data sizes that are powers of two. There is also a large body of literature treating issues such as the choice of the "optimal" wavelets and the performance comparison of competing algorithms. With the advent of telemedicine, there is a strong incentive to extend these techniques to higher dimensional data such as dynamic three-dimensional (3-D) echocardiography [four-dimensional (4-D) datasets]. One of the practical difficulties is that the size of this data is often not a multiple of a power of two, which can lead to increased computational complexity and impaired compression power. Our contribution in this paper is to present a genuine 4-D extension of the well-known zerotree algorithm for arbitrarily sized data. The key component of our method is a one-dimensional wavelet algorithm that can handle arbitrarily sized input signals. The method uses a pair of symmetric/antisymmetric wavelets (10/6) together with some appropriate midpoint symmetry boundary conditions that reduce border artifacts. The zerotree structure is also adapted so that it can accommodate noneven data splitting. We have applied our method to the compression of real 3-D dynamic sequences from clinical cardiac ultrasound examinations. Our new algorithm compares very favorably with other more ad hoc adaptations (image extension and tiling) of the standard powers-of-two methods, in terms of both compression performance and computational cost. It is vastly superior to slice-by-slice wavelet encoding. This was seen not only in numerical image quality parameters but also in expert ratings, where significant improvement using the new approach could be documented. Our validation experiments show that one can safely compress 4-D data sets at ratios of 128:1 without compromising the diagnostic value of the images. We also display some more extreme compression results at ratios of 2000:1 where some key diagnostically relevant key features are preserved.

Comparison of infrared and 3D digital image correlation techniques applied for mechanical testing of materials

NASA Astrophysics Data System (ADS)

Krstulović-Opara, Lovre; Surjak, Martin; Vesenjak, Matej; Tonković, Zdenko; Kodvanj, Janoš; Domazet, Željko

2015-11-01

To investigate the applicability of infrared thermography as a tool for acquiring dynamic yielding in metals, a comparison of infrared thermography with three dimensional digital image correlation has been made. Dynamical tension tests and three point bending tests of aluminum alloys have been performed to evaluate results obtained by IR thermography in order to detect capabilities and limits for these two methods. Both approaches detect pastification zone migrations during the yielding process. The results of the tension test and three point bending test proved the validity of the IR approach as a method for evaluating the dynamic yielding process when used on complex structures such as cellular porous materials. The stability of the yielding process in the three point bending test, as contrary to the fluctuation of the plastification front in the tension test, is of great importance for the validation of numerical constitutive models. The research proved strong performance, robustness and reliability of the IR approach when used to evaluate yielding during dynamic loading processes, while the 3D DIC method proved to be superior in the low velocity loading regimes. This research based on two basic tests, proved the conclusions and suggestions presented in our previous research on porous materials where middle wave infrared thermography was applied.

Measurement of 3-D Vibrational Motion by Dynamic Photogrammetry Using Least-Square Image Matching for Sub-Pixel Targeting to Improve Accuracy.

PubMed

Lee, Hyoseong; Rhee, Huinam; Oh, Jae Hong; Park, Jin Ho

2016-03-11

This paper deals with an improved methodology to measure three-dimensional dynamic displacements of a structure by digital close-range photogrammetry. A series of stereo images of a vibrating structure installed with targets are taken at specified intervals by using two daily-use cameras. A new methodology is proposed to accurately trace the spatial displacement of each target in three-dimensional space. This method combines the correlation and the least-square image matching so that the sub-pixel targeting can be obtained to increase the measurement accuracy. Collinearity and space resection theory are used to determine the interior and exterior orientation parameters. To verify the proposed method, experiments have been performed to measure displacements of a cantilevered beam excited by an electrodynamic shaker, which is vibrating in a complex configuration with mixed bending and torsional motions simultaneously with multiple frequencies. The results by the present method showed good agreement with the measurement by two laser displacement sensors. The proposed methodology only requires inexpensive daily-use cameras, and can remotely detect the dynamic displacement of a structure vibrating in a complex three-dimensional defection shape up to sub-pixel accuracy. It has abundant potential applications to various fields, e.g., remote vibration monitoring of an inaccessible or dangerous facility.

Measurement of 3-D Vibrational Motion by Dynamic Photogrammetry Using Least-Square Image Matching for Sub-Pixel Targeting to Improve Accuracy

PubMed Central

Lee, Hyoseong; Rhee, Huinam; Oh, Jae Hong; Park, Jin Ho

2016-01-01

This paper deals with an improved methodology to measure three-dimensional dynamic displacements of a structure by digital close-range photogrammetry. A series of stereo images of a vibrating structure installed with targets are taken at specified intervals by using two daily-use cameras. A new methodology is proposed to accurately trace the spatial displacement of each target in three-dimensional space. This method combines the correlation and the least-square image matching so that the sub-pixel targeting can be obtained to increase the measurement accuracy. Collinearity and space resection theory are used to determine the interior and exterior orientation parameters. To verify the proposed method, experiments have been performed to measure displacements of a cantilevered beam excited by an electrodynamic shaker, which is vibrating in a complex configuration with mixed bending and torsional motions simultaneously with multiple frequencies. The results by the present method showed good agreement with the measurement by two laser displacement sensors. The proposed methodology only requires inexpensive daily-use cameras, and can remotely detect the dynamic displacement of a structure vibrating in a complex three-dimensional defection shape up to sub-pixel accuracy. It has abundant potential applications to various fields, e.g., remote vibration monitoring of an inaccessible or dangerous facility. PMID:26978366

Evolutionary dynamics of 3D genome architecture following polyploidization in cotton.

PubMed

Wang, Maojun; Wang, Pengcheng; Lin, Min; Ye, Zhengxiu; Li, Guoliang; Tu, Lili; Shen, Chao; Li, Jianying; Yang, Qingyong; Zhang, Xianlong

2018-02-01

The formation of polyploids significantly increases the complexity of transcriptional regulation, which is expected to be reflected in sophisticated higher-order chromatin structures. However, knowledge of three-dimensional (3D) genome structure and its dynamics during polyploidization remains poor. Here, we characterize 3D genome architectures for diploid and tetraploid cotton, and find the existence of A/B compartments and topologically associated domains (TADs). By comparing each subgenome in tetraploids with its extant diploid progenitor, we find that genome allopolyploidization has contributed to the switching of A/B compartments and the reorganization of TADs in both subgenomes. We also show that the formation of TAD boundaries during polyploidization preferentially occurs in open chromatin, coinciding with the deposition of active chromatin modification. Furthermore, analysis of inter-subgenomic chromatin interactions has revealed the spatial proximity of homoeologous genes, possibly associated with their coordinated expression. This study advances our understanding of chromatin organization in plants and sheds new light on the relationship between 3D genome evolution and transcriptional regulation.

STARS: A general-purpose finite element computer program for analysis of engineering structures

NASA Technical Reports Server (NTRS)

Gupta, K. K.

1984-01-01

STARS (Structural Analysis Routines) is primarily an interactive, graphics-oriented, finite-element computer program for analyzing the static, stability, free vibration, and dynamic responses of damped and undamped structures, including rotating systems. The element library consists of one-dimensional (1-D) line elements, two-dimensional (2-D) triangular and quadrilateral shell elements, and three-dimensional (3-D) tetrahedral and hexahedral solid elements. These elements enable the solution of structural problems that include truss, beam, space frame, plane, plate, shell, and solid structures, or any combination thereof. Zero, finite, and interdependent deflection boundary conditions can be implemented by the program. The associated dynamic response analysis capability provides for initial deformation and velocity inputs, whereas the transient excitation may be either forces or accelerations. An effective in-core or out-of-core solution strategy is automatically employed by the program, depending on the size of the problem. Data input may be at random within a data set, and the program offers certain automatic data-generation features. Input data are formatted as an optimal combination of free and fixed formats. Interactive graphics capabilities enable convenient display of nodal deformations, mode shapes, and element stresses.

Three-dimensional scene reconstruction from a two-dimensional image

NASA Astrophysics Data System (ADS)

Parkins, Franz; Jacobs, Eddie

2017-05-01

We propose and simulate a method of reconstructing a three-dimensional scene from a two-dimensional image for developing and augmenting world models for autonomous navigation. This is an extension of the Perspective-n-Point (PnP) method which uses a sampling of the 3D scene, 2D image point parings, and Random Sampling Consensus (RANSAC) to infer the pose of the object and produce a 3D mesh of the original scene. Using object recognition and segmentation, we simulate the implementation on a scene of 3D objects with an eye to implementation on embeddable hardware. The final solution will be deployed on the NVIDIA Tegra platform.

Dynamic CT myocardial perfusion imaging: performance of 3D semi-automated evaluation software.

PubMed

Ebersberger, Ullrich; Marcus, Roy P; Schoepf, U Joseph; Lo, Gladys G; Wang, Yining; Blanke, Philipp; Geyer, Lucas L; Gray, J Cranston; McQuiston, Andrew D; Cho, Young Jun; Scheuering, Michael; Canstein, Christian; Nikolaou, Konstantin; Hoffmann, Ellen; Bamberg, Fabian

2014-01-01

To evaluate the performance of three-dimensional semi-automated evaluation software for the assessment of myocardial blood flow (MBF) and blood volume (MBV) at dynamic myocardial perfusion computed tomography (CT). Volume-based software relying on marginal space learning and probabilistic boosting tree-based contour fitting was applied to CT myocardial perfusion imaging data of 37 subjects. In addition, all image data were analysed manually and both approaches were compared with SPECT findings. Study endpoints included time of analysis and conventional measures of diagnostic accuracy. Of 592 analysable segments, 42 showed perfusion defects on SPECT. Average analysis times for the manual and software-based approaches were 49.1 ± 11.2 and 16.5 ± 3.7 min respectively (P < 0.01). There was strong agreement between the two measures of interest (MBF, ICC = 0.91, and MBV, ICC = 0.88, both P < 0.01) and no significant difference in MBF/MBV with respect to diagnostic accuracy between the two approaches for both MBF and MBV for manual versus software-based approach; respectively; all comparisons P > 0.05. Three-dimensional semi-automated evaluation of dynamic myocardial perfusion CT data provides similar measures and diagnostic accuracy to manual evaluation, albeit with substantially reduced analysis times. This capability may aid the integration of this test into clinical workflows. • Myocardial perfusion CT is attractive for comprehensive coronary heart disease assessment. • Traditional image analysis methods are cumbersome and time-consuming. • Automated 3D perfusion software shortens analysis times. • Automated 3D perfusion software increases standardisation of myocardial perfusion CT. • Automated, standardised analysis fosters myocardial perfusion CT integration into clinical practice.

Seamless lamination of a concave-convex architecture with single-layer graphene.

PubMed

Park, Ji-Hoon; Lim, Taekyung; Baik, Jaeyoon; Seo, Keumyoung; Moon, Youngkwon; Park, Noejung; Shin, Hyun-Joon; Kwak, Sang Kyu; Ju, Sanghyun; Ahn, Joung Real

2015-11-21

Graphene has been used as an electrode and channel material in electronic devices because of its superior physical properties. Recently, electronic devices have changed from a planar to a complicated three-dimensional (3D) geometry to overcome the limitations of planar devices. The evolution of electronic devices requires that graphene be adaptable to a 3D substrate. Here, we demonstrate that chemical-vapor-deposited single-layer graphene can be transferred onto a silicon dioxide substrate with a 3D geometry, such as a concave-convex architecture. A variety of silicon dioxide concave-convex architectures were uniformly and seamlessly laminated with graphene using a thermal treatment. The planar graphene was stretched to cover the concave-convex architecture, and the resulting strain on the curved graphene was spatially resolved by confocal Raman spectroscopy; molecular dynamic simulations were also conducted and supported the observations. Changes in electrical resistivity caused by the spatially varying strain induced as the graphene-silicon dioxide laminate varies dimensionally from 2D to 3D were measured by using a four-point probe. The resistivity measurements suggest that the electrical resistivity can be systematically controlled by the 3D geometry of the graphene-silicon dioxide laminate. This 3D graphene-insulator laminate will broaden the range of graphene applications beyond planar structures to 3D materials.

AdS3 to dS3 transition in the near horizon of asymptotically de Sitter solutions

NASA Astrophysics Data System (ADS)

Sadeghian, S.; Vahidinia, M. H.

2017-08-01

We consider two solutions of Einstein-Λ theory which admit the extremal vanishing horizon (EVH) limit, odd-dimensional multispinning Kerr black hole (in the presence of cosmological constant) and cosmological soliton. We show that the near horizon EVH geometry of Kerr has a three-dimensional maximally symmetric subspace whose curvature depends on rotational parameters and the cosmological constant. In the Kerr-dS case, this subspace interpolates between AdS3 , three-dimensional flat and dS3 by varying rotational parameters, while the near horizon of the EVH cosmological soliton always has a dS3 . The feature of the EVH cosmological soliton is that it is regular everywhere on the horizon. In the near EVH case, these three-dimensional parts turn into the corresponding locally maximally symmetric spacetimes with a horizon: Kerr-dS3 , flat space cosmology or BTZ black hole. We show that their thermodynamics match with the thermodynamics of the original near EVH black holes. We also briefly discuss the holographic two-dimensional CFT dual to the near horizon of EVH solutions.

Dynamical density delay maps: simple, new method for visualising the behaviour of complex systems

PubMed Central

2014-01-01

Background Physiologic signals, such as cardiac interbeat intervals, exhibit complex fluctuations. However, capturing important dynamical properties, including nonstationarities may not be feasible from conventional time series graphical representations. Methods We introduce a simple-to-implement visualisation method, termed dynamical density delay mapping (“D3-Map” technique) that provides an animated representation of a system’s dynamics. The method is based on a generalization of conventional two-dimensional (2D) Poincaré plots, which are scatter plots where each data point, x(n), in a time series is plotted against the adjacent one, x(n + 1). First, we divide the original time series, x(n) (n = 1,…, N), into a sequence of segments (windows). Next, for each segment, a three-dimensional (3D) Poincaré surface plot of x(n), x(n + 1), h[x(n),x(n + 1)] is generated, in which the third dimension, h, represents the relative frequency of occurrence of each (x(n),x(n + 1)) point. This 3D Poincaré surface is then chromatised by mapping the relative frequency h values onto a colour scheme. We also generate a colourised 2D contour plot from each time series segment using the same colourmap scheme as for the 3D Poincaré surface. Finally, the original time series graph, the colourised 3D Poincaré surface plot, and its projection as a colourised 2D contour map for each segment, are animated to create the full “D3-Map.” Results We first exemplify the D3-Map method using the cardiac interbeat interval time series from a healthy subject during sleeping hours. The animations uncover complex dynamical changes, such as transitions between states, and the relative amount of time the system spends in each state. We also illustrate the utility of the method in detecting hidden temporal patterns in the heart rate dynamics of a patient with atrial fibrillation. The videos, as well as the source code, are made publicly available. Conclusions Animations based on density delay maps provide a new way of visualising dynamical properties of complex systems not apparent in time series graphs or standard Poincaré plot representations. Trainees in a variety of fields may find the animations useful as illustrations of fundamental but challenging concepts, such as nonstationarity and multistability. For investigators, the method may facilitate data exploration. PMID:24438439

Three-Dimensional (3D) Printers in Libraries: Perspective and Preliminary Safety Analysis

ERIC Educational Resources Information Center

Bharti, Neelam; Singh, Shailendra

2017-01-01

As an emerging technology, three-dimensional (3D) printing has gained much attention as a rapid prototyping and small-scale manufacturing technology around the world. In the changing scenario of library inclusion, Makerspaces are becoming a part of most public and academic libraries, and 3D printing is one of the technologies included in…

Three-Dimensional Interpretation of Sculptural Heritage with Digital and Tangible 3D Printed Replicas

ERIC Educational Resources Information Center

Saorin, José Luis; Carbonell-Carrera, Carlos; Cantero, Jorge de la Torre; Meier, Cecile; Aleman, Drago Diaz

2017-01-01

Spatial interpretation features as a skill to acquire in the educational curricula. The visualization and interpretation of three-dimensional objects in tactile devices and the possibility of digital manufacturing with 3D printers, offers an opportunity to include replicas of sculptures in teaching and, thus, facilitate the 3D interpretation of…

Fuzzy rule-based image segmentation in dynamic MR images of the liver

NASA Astrophysics Data System (ADS)

Kobashi, Syoji; Hata, Yutaka; Tokimoto, Yasuhiro; Ishikawa, Makato

2000-06-01

This paper presents a fuzzy rule-based region growing method for segmenting two-dimensional (2-D) and three-dimensional (3- D) magnetic resonance (MR) images. The method is an extension of the conventional region growing method. The proposed method evaluates the growing criteria by using fuzzy inference techniques. The use of the fuzzy if-then rules is appropriate for describing the knowledge of the legions on the MR images. To evaluate the performance of the proposed method, it was applied to artificially generated images. In comparison with the conventional method, the proposed method shows high robustness for noisy images. The method then applied for segmenting the dynamic MR images of the liver. The dynamic MR imaging has been used for diagnosis of hepatocellular carcinoma (HCC), portal hypertension, and so on. Segmenting the liver, portal vein (PV), and inferior vena cava (IVC) can give useful description for the diagnosis, and is a basis work of a pres-surgery planning system and a virtual endoscope. To apply the proposed method, fuzzy if-then rules are derived from the time-density curve of ROIs. In the experimental results, the 2-D reconstructed and 3-D rendered images of the segmented liver, PV, and IVC are shown. The evaluation by a physician shows that the generated images are comparable to the hepatic anatomy, and they would be useful to understanding, diagnosis, and pre-surgery planning.

The accuracy of three-dimensional fused deposition modeling (FDM) compared with three-dimensional CT-Scans on the measurement of the mandibular ramus vertical length, gonion-menton length, and gonial angle

NASA Astrophysics Data System (ADS)

Savitri, I. T.; Badri, C.; Sulistyani, L. D.

2017-08-01

Presurgical treatment planning plays an important role in the reconstruction and correction of defects in the craniomaxillofacial region. The advance of solid freeform fabrication techniques has significantly improved the process of preparing a biomodel using computer-aided design and data from medical imaging. Many factors are implicated in the accuracy of the 3D model. To determine the accuracy of three-dimensional fused deposition modeling (FDM) models compared with three-dimensional CT scans in the measurement of the mandibular ramus vertical length, gonion-menton length, and gonial angle. Eight 3D models were produced from the CT scan data (DICOM file) of eight patients at the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, University of Indonesia, Cipto Mangunkusumo Hospital. Three measurements were done three times by two examiners. The measurements of the 3D CT scans were made using OsiriX software, while the measurements of the 3D models were made using a digital caliper and goniometry. The measurement results were then compared. There is no significant difference between the measurements of the mandibular ramus vertical length, gonion-menton length, and gonial angle using 3D CT scans and FDM 3D models. FDM 3D models are considered accurate and are acceptable for clinical applications in dental and craniomaxillofacial surgery.

Quantifying frontal plane knee motion during single limb squats: reliability and validity of 2-dimensional measures.

PubMed

Gwynne, Craig R; Curran, Sarah A

2014-12-01

Clinical assessment of lower limb kinematics during dynamic tasks may identify individuals who demonstrate abnormal movement patterns that may lead to etiology of exacerbation of knee conditions such as patellofemoral joint (PFJt) pain. The purpose of this study was to determine the reliability, validity and associated measurement error of a clinically appropriate two-dimensional (2-D) procedure of quantifying frontal plane knee alignment during single limb squats. Nine female and nine male recreationally active subjects with no history of PFJt pain had frontal plane limb alignment assessed using three-dimensional (3-D) motion analysis and digital video cameras (2-D analysis) while performing single limb squats. The association between 2-D and 3-D measures was quantified using Pearson's product correlation coefficients. Intraclass correlation coefficients (ICCs) were determined for within- and between-session reliability of 2-D data and standard error of measurement (SEM) was used to establish measurement error. Frontal plane limb alignment assessed with 2-D analysis demonstrated good correlation compared with 3-D methods (r = 0.64 to 0.78, p < 0.001). Within-session (0.86) and between-session ICCs (0.74) demonstrated good reliability for 2-D measures and SEM scores ranged from 2° to 4°. 2-D measures have good consistency and may provide a valid measure of lower limb alignment when compared to existing 3-D methods. Assessment of lower limb kinematics using 2-D methods may be an accurate and clinically useful alternative to 3-D motion analysis when identifying individuals who demonstrate abnormal movement patterns associated with PFJt pain. 2b.

A one-dimensional free energy surface does not account for two-probe folding kinetics of protein alpha(3)D.

PubMed

Liu, Feng; Dumont, Charles; Zhu, Yongjin; DeGrado, William F; Gai, Feng; Gruebele, Martin

2009-02-14

We present fluorescence-detected measurements of the temperature-jump relaxation kinetics of the designed three-helix bundle protein alpha(3)D taken under solvent conditions identical to previous infrared-detected kinetics. The fluorescence-detected rate is similar to the IR-detected rate only at the lowest temperature where we could measure it (326 K). The fluorescence-detected rate decreases by a factor of 3 over the 326-344 K temperature range, whereas the IR-detected rate remains nearly constant over the same range. To investigate this probe dependence, we tested an extensive set of physically reasonable one-dimensional (1D) free energy surfaces by Langevin dynamics simulation. The simulations included coordinate- and temperature-dependent roughness, diffusion coefficients, and IR/fluorescence spectroscopic signatures. None of these can reproduce the IR and fluorescence data simultaneously, forcing us to the conclusion that a 1D free energy surface cannot accurately describe the folding of alpha(3)D. This supports the hypothesis that alpha(3)D has a multidimensional free energy surface conducive to downhill folding at 326 K, and that it is already an incipient downhill folder with probe-dependent kinetics near its melting point.

Fabrication of three-dimensional millimeter-height structures using direct ultraviolet lithography on liquid-state photoresist for simple and fast manufacturing

NASA Astrophysics Data System (ADS)

Kim, Jungkwun; Yoon, Yong-Kyu

2015-07-01

A rapid three-dimensional (3-D) ultraviolet (UV) lithography process for the fabrication of millimeter-tall high aspect ratio complex structures is presented. The liquid-state negative-tone photosensitive polyurethane, LF55GN, has been directly photopatterned using multidirectionally projected UV light for 3-D micropattern formation. The proposed lithographic scheme enabled us to overcome the maximum height obtained with a photopatternable epoxy, SU8, which has been conventionally most commonly used for the fabrication of tall and high aspect ratio microstructures. Also, the fabrication process time has been significantly reduced by eliminating photoresist-baking steps. Computer-controlled multidirectional UV lithography has been employed to fabricate 3-D structures, where the UV-exposure substrate is dynamically tilt-rotating during UV exposure to create various 3-D ray traces in the polyurethane layer. LF55GN has been characterized to provide feasible fabrication conditions for the multidirectional UV lithography. Very tall structures including a 6-mm tall triangular slab and a 5-mm tall hexablaze have been successfully fabricated. A 4.5-mm tall air-lifted polymer-core bowtie monopole antenna, which is the tallest monopole structure fabricated by photolithography and subsequent metallization, has been successfully demonstrated. The antenna shows a resonant radiation frequency of 12.34 GHz, a return loss of 36 dB, and a 10 dB bandwidth of 7%.

Pressure-based high-order TVD methodology for dynamic stall control

NASA Astrophysics Data System (ADS)

Yang, H. Q.; Przekwas, A. J.

1992-01-01

The quantitative prediction of the dynamics of separating unsteady flows, such as dynamic stall, is of crucial importance. This six-month SBIR Phase 1 study has developed several new pressure-based methodologies for solving 3D Navier-Stokes equations in both stationary and moving (body-comforting) coordinates. The present pressure-based algorithm is equally efficient for low speed incompressible flows and high speed compressible flows. The discretization of convective terms by the presently developed high-order TVD schemes requires no artificial dissipation and can properly resolve the concentrated vortices in the wing-body with minimum numerical diffusion. It is demonstrated that the proposed Newton's iteration technique not only increases the convergence rate but also strongly couples the iteration between pressure and velocities. The proposed hyperbolization of the pressure correction equation is shown to increase the solver's efficiency. The above proposed methodologies were implemented in an existing CFD code, REFLEQS. The modified code was used to simulate both static and dynamic stalls on two- and three-dimensional wing-body configurations. Three-dimensional effect and flow physics are discussed.

Introducing a Virtual Reality Experience in Anatomic Pathology Education.

PubMed

Madrigal, Emilio; Prajapati, Shyam; Hernandez-Prera, Juan C

2016-10-01

A proper examination of surgical specimens is fundamental in anatomic pathology (AP) education. However, the resources available to residents may not always be suitable for efficient skill acquisition. We propose a method to enhance AP education by introducing high-definition videos featuring methods for appropriate specimen handling, viewable on two-dimensional (2D) and stereoscopic three-dimensional (3D) platforms. A stereo camera system recorded the gross processing of commonly encountered specimens. Three edited videos, with instructional audio voiceovers, were experienced by nine junior residents in a crossover study to assess the effects of the exposure (2D vs 3D movie views) on self-reported physiologic symptoms. A questionnaire was used to analyze viewer acceptance. All surveyed residents found the videos beneficial in preparation to examine a new specimen type. Viewer data suggest an improvement in specimen handling confidence and knowledge and enthusiasm toward 3D technology. None of the participants encountered significant motion sickness. Our novel method provides the foundation to create a robust teaching library. AP is inherently a visual discipline, and by building on the strengths of traditional teaching methods, our dynamic approach allows viewers to appreciate the procedural actions involved in specimen processing. © American Society for Clinical Pathology, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Echocardiography Comparison Between Two and Three Dimensional Echocardiograms

NASA Technical Reports Server (NTRS)

2003-01-01

Echocardiography uses sound waves to image the heart and other organs. Developing a compact version of the latest technology improved the ease of monitoring crew member health, a critical task during long space flights. NASA researchers plan to adapt the three-dimensional (3-D) echocardiogram for space flight. The two-dimensional (2-D) echocardiogram utilized in orbit on the International Space Station (ISS) was effective, but difficult to use with precision. A heart image from a 2-D echocardiogram (left) is of a better quality than that from a 3-D device (right), but the 3-D imaging procedure is more user-friendly.

Virtual three-dimensional blackboard: three-dimensional finger tracking with a single camera

NASA Astrophysics Data System (ADS)

Wu, Andrew; Hassan-Shafique, Khurram; Shah, Mubarak; da Vitoria Lobo, N.

2004-01-01

We present a method for three-dimensional (3D) tracking of a human finger from a monocular sequence of images. To recover the third dimension from the two-dimensional images, we use the fact that the motion of the human arm is highly constrained owing to the dependencies between elbow and forearm and the physical constraints on joint angles. We use these anthropometric constraints to derive a 3D trajectory of a gesticulating arm. The system is fully automated and does not require human intervention. The system presented can be used as a visualization tool, as a user-input interface, or as part of some gesture-analysis system in which 3D information is important.

Three-dimensional macro-structures of two-dimensional nanomaterials.

PubMed

Shehzad, Khurram; Xu, Yang; Gao, Chao; Duan, Xiangfeng

2016-10-21

If two-dimensional (2D) nanomaterials are ever to be utilized as components of practical, macroscopic devices on a large scale, there is a complementary need to controllably assemble these 2D building blocks into more sophisticated and hierarchical three-dimensional (3D) architectures. Such a capability is key to design and build complex, functional devices with tailored properties. This review provides a comprehensive overview of the various experimental strategies currently used to fabricate the 3D macro-structures of 2D nanomaterials. Additionally, various approaches for the decoration of the 3D macro-structures with organic molecules, polymers, and inorganic materials are reviewed. Finally, we discuss the applications of 3D macro-structures, especially in the areas of energy, environment, sensing, and electronics, and describe the existing challenges and the outlook for this fast emerging field.

Two-dimensional vocal tracts with three-dimensional behavior in the numerical generation of vowels.

PubMed

Arnela, Marc; Guasch, Oriol

2014-01-01

Two-dimensional (2D) numerical simulations of vocal tract acoustics may provide a good balance between the high quality of three-dimensional (3D) finite element approaches and the low computational cost of one-dimensional (1D) techniques. However, 2D models are usually generated by considering the 2D vocal tract as a midsagittal cut of a 3D version, i.e., using the same radius function, wall impedance, glottal flow, and radiation losses as in 3D, which leads to strong discrepancies in the resulting vocal tract transfer functions. In this work, a four step methodology is proposed to match the behavior of 2D simulations with that of 3D vocal tracts with circular cross-sections. First, the 2D vocal tract profile becomes modified to tune the formant locations. Second, the 2D wall impedance is adjusted to fit the formant bandwidths. Third, the 2D glottal flow gets scaled to recover 3D pressure levels. Fourth and last, the 2D radiation model is tuned to match the 3D model following an optimization process. The procedure is tested for vowels /a/, /i/, and /u/ and the obtained results are compared with those of a full 3D simulation, a conventional 2D approach, and a 1D chain matrix model.

Two- and three-dimensional natural and mixed convection simulation using modular zonal models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wurtz, E.; Nataf, J.M.; Winkelmann, F.

We demonstrate the use of the zonal model approach, which is a simplified method for calculating natural and mixed convection in rooms. Zonal models use a coarse grid and use balance equations, state equations, hydrostatic pressure drop equations and power law equations of the form {ital m} = {ital C}{Delta}{sup {ital n}}. The advantage of the zonal approach and its modular implementation are discussed. The zonal model resolution of nonlinear equation systems is demonstrated for three cases: a 2-D room, a 3-D room and a pair of 3-D rooms separated by a partition with an opening. A sensitivity analysis withmore » respect to physical parameters and grid coarseness is presented. Results are compared to computational fluid dynamics (CFD) calculations and experimental data.« less

In Vivo, High-Frequency Three-Dimensional Cardiac MR Elastography: Feasibility in Normal Volunteers

PubMed Central

Arani, Arvin; Glaser, Kevin L.; Arunachalam, Shivaram P.; Rossman, Phillip J.; Lake, David S.; Trzasko, Joshua D.; Manduca, Armando; McGee, Kiaran P.; Ehman, Richard L.; Araoz, Philip A.

2016-01-01

Purpose Noninvasive stiffness imaging techniques (elastography) can image myocardial tissue biomechanics in vivo. For cardiac MR elastography (MRE) techniques, the optimal vibration frequency for in vivo experiments is unknown. Furthermore, the accuracy of cardiac MRE has never been evaluated in a geometrically accurate phantom. Therefore, the purpose of this study was to determine the necessary driving frequency to obtain accurate three-dimensional (3D) cardiac MRE stiffness estimates in a geometrically accurate diastolic cardiac phantom and to determine the optimal vibration frequency that can be introduced in healthy volunteers. Methods The 3D cardiac MRE was performed on eight healthy volunteers using 80 Hz, 100 Hz, 140 Hz, 180 Hz, and 220 Hz vibration frequencies. These frequencies were tested in a geometrically accurate diastolic heart phantom and compared with dynamic mechanical analysis (DMA). Results The 3D Cardiac MRE was shown to be feasible in volunteers at frequencies as high as 180 Hz. MRE and DMA agreed within 5% at frequencies greater than 180 Hz in the cardiac phantom. However, octahedral shear strain signal to noise ratios and myocardial coverage was shown to be highest at a frequency of 140 Hz across all subjects. Conclusion This study motivates future evaluation of high-frequency 3D MRE in patient populations. PMID:26778442

Viscous Incompressible Flow Computations for 3-D Steady and Unsteady Flows

NASA Technical Reports Server (NTRS)

Kwak, Dochan

2001-01-01

This viewgraph presentation gives an overview of viscous incompressible flow computations for three-dimensional steady and unsteady flows. Details are given on the use of computational fluid dynamics (CFD) as an engineering tool, solution methods for incompressible Navier-Stokes equations, numerical and physical characteristics of the primitive variable approach, and the role of CFD in the past and in current engineering and research applications.

Three-dimensional high-definition neuroendoscopic surgery: a controlled comparative laboratory study with two-dimensional endoscopy and clinical application.

PubMed

Inoue, Daisuke; Yoshimoto, Koji; Uemura, Munenori; Yoshida, Masaki; Ohuchida, Kenoki; Kenmotsu, Hajime; Tomikawa, Morimasa; Sasaki, Tomio; Hashizume, Makoto

2013-11-01

The purpose of this research was to investigate the usefulness of three-dimensional (3D) endoscopy compared with two-dimensional (2D) endoscopy in neuroendoscopic surgeries in a comparative study and to test the clinical applications. Forty-three examinees were divided into three groups according to their endoscopic experience: novice, beginner, or expert. Examinees performed three separate tasks using 3D and 2D endoscopy. A recently developed 3D high-definition (HD) neuroendoscope, 4.7 mm in diameter (Shinko Optical Co., Ltd., Tokyo, Japan) was used. In one of the three tasks, we developed a full-sized skull model of acrylic-based plastic using a 3D printer and a patient's thin slice computed tomography data, and evaluated the execution time and total path length of the tip of the pointer using an optical tracking system. Sixteen patients underwent endoscopic transnasal transsphenoidal pituitary surgery using both 3D and 2D endoscopy. Horizontal motion was evaluated using task 1, and anteroposterior motion was evaluated with task 3. Execution time and total path length in task 3 using the 3D system in both novice and beginner groups were significantly shorter than with the 2D system (p < 0.05), although no significant difference between 2D and 3D systems in task 1 was seen. In both the novice and beginner groups, the 3D system was better for depth perception than horizontal motion. No difference was seen in the expert group in this regard. The 3D HD endoscope was used for the pituitary surgery and was found very useful to identify the spatial relationship of carotid arteries and bony structures. The use of a 3D neuroendoscope improved depth perception and task performance. Our results suggest that 3D endoscopes could shorten the learning curve of young neurosurgeons and play an important role in both general surgery and neurosurgery. Georg Thieme Verlag KG Stuttgart · New York.

Gas Dynamic Modernization of Axial Uncooled Turbine by Means of CFD and Optimization Software

NASA Astrophysics Data System (ADS)

Marchukov, E. Yu; Egorov, I. N.

2018-01-01

The results of multicriteria optimization of three-stage low-pressure turbine are described in the paper. The aim of the optimization is to improve turbine operation process by three criteria: turbine outlet flow angle, value of residual swirl at the turbine outlet, and turbine efficiency. Full reprofiling of all blade rows is carried out while solving optimization problem. Reprofiling includes a change in both shape of flat blade sections (profiles) and three-dimensional shape of the blades. The study is carried out with 3D numerical models of turbines.

Three-Dimensional Anatomic Evaluation of the Anterior Cruciate Ligament for Planning Reconstruction

PubMed Central

Hoshino, Yuichi; Kim, Donghwi; Fu, Freddie H.

2012-01-01

Anatomic study related to the anterior cruciate ligament (ACL) reconstruction surgery has been developed in accordance with the progress of imaging technology. Advances in imaging techniques, especially the move from two-dimensional (2D) to three-dimensional (3D) image analysis, substantially contribute to anatomic understanding and its application to advanced ACL reconstruction surgery. This paper introduces previous research about image analysis of the ACL anatomy and its application to ACL reconstruction surgery. Crucial bony landmarks for the accurate placement of the ACL graft can be identified by 3D imaging technique. Additionally, 3D-CT analysis of the ACL insertion site anatomy provides better and more consistent evaluation than conventional “clock-face” reference and roentgenologic quadrant method. Since the human anatomy has a complex three-dimensional structure, further anatomic research using three-dimensional imaging analysis and its clinical application by navigation system or other technologies is warranted for the improvement of the ACL reconstruction. PMID:22567310

3D motion picture of transparent gas flow by parallel phase-shifting digital holography

NASA Astrophysics Data System (ADS)

Awatsuji, Yasuhiro; Fukuda, Takahito; Wang, Yexin; Xia, Peng; Kakue, Takashi; Nishio, Kenzo; Matoba, Osamu

2018-03-01

Parallel phase-shifting digital holography is a technique capable of recording three-dimensional (3D) motion picture of dynamic object, quantitatively. This technique can record single hologram of an object with an image sensor having a phase-shift array device and reconstructs the instantaneous 3D image of the object with a computer. In this technique, a single hologram in which the multiple holograms required for phase-shifting digital holography are multiplexed by using space-division multiplexing technique pixel by pixel. We demonstrate 3D motion picture of dynamic and transparent gas flow recorded and reconstructed by the technique. A compressed air duster was used to generate the gas flow. A motion picture of the hologram of the gas flow was recorded at 180,000 frames/s by parallel phase-shifting digital holography. The phase motion picture of the gas flow was reconstructed from the motion picture of the hologram. The Abel inversion was applied to the phase motion picture and then the 3D motion picture of the gas flow was obtained.

Performance evaluation of an improved optical computed tomography polymer gel dosimeter system for 3D dose verification of static and dynamic phantom deliveries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopatiuk-Tirpak, O.; Langen, K. M.; Meeks, S. L.

2008-09-15

The performance of a next-generation optical computed tomography scanner (OCTOPUS-5X) is characterized in the context of three-dimensional gel dosimetry. Large-volume (2.2 L), muscle-equivalent, radiation-sensitive polymer gel dosimeters (BANG-3) were used. Improvements in scanner design leading to shorter acquisition times are discussed. The spatial resolution, detectable absorbance range, and reproducibility are assessed. An efficient method for calibrating gel dosimeters using the depth-dose relationship is applied, with photon- and electron-based deliveries yielding equivalent results. A procedure involving a preirradiation scan was used to reduce the edge artifacts in reconstructed images, thereby increasing the useful cross-sectional area of the dosimeter by nearly amore » factor of 2. Dose distributions derived from optical density measurements using the calibration coefficient show good agreement with the treatment planning system simulations and radiographic film measurements. The feasibility of use for motion (four-dimensional) dosimetry is demonstrated on an example comparing dose distributions from static and dynamic delivery of a single-field photon plan. The capability to visualize three-dimensional dose distributions is also illustrated.« less

Three-dimensional compound comparison methods and their application in drug discovery.

PubMed

Shin, Woong-Hee; Zhu, Xiaolei; Bures, Mark Gregory; Kihara, Daisuke

2015-07-16

Virtual screening has been widely used in the drug discovery process. Ligand-based virtual screening (LBVS) methods compare a library of compounds with a known active ligand. Two notable advantages of LBVS methods are that they do not require structural information of a target receptor and that they are faster than structure-based methods. LBVS methods can be classified based on the complexity of ligand structure information utilized: one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D). Unlike 1D and 2D methods, 3D methods can have enhanced performance since they treat the conformational flexibility of compounds. In this paper, a number of 3D methods will be reviewed. In addition, four representative 3D methods were benchmarked to understand their performance in virtual screening. Specifically, we tested overall performance in key aspects including the ability to find dissimilar active compounds, and computational speed.

Multi-purpose two- and three-dimensional momentum imaging of charged particles for attosecond experiments at 1 kHz repetition rate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Månsson, Erik P., E-mail: erik.mansson@sljus.lu.se; Sorensen, Stacey L.; Gisselbrecht, Mathieu

2014-12-15

We report on the versatile design and operation of a two-sided spectrometer for the imaging of charged-particle momenta in two dimensions (2D) and three dimensions (3D). The benefits of 3D detection are to discern particles of different mass and to study correlations between fragments from multi-ionization processes, while 2D detectors are more efficient for single-ionization applications. Combining these detector types in one instrument allows us to detect positive and negative particles simultaneously and to reduce acquisition times by using the 2D detector at a higher ionization rate when the third dimension is not required. The combined access to electronic andmore » nuclear dynamics available when both sides are used together is important for studying photoreactions in samples of increasing complexity. The possibilities and limitations of 3D momentum imaging of electrons or ions in the same spectrometer geometry are investigated analytically and three different modes of operation demonstrated experimentally, with infrared or extreme ultraviolet light and an atomic/molecular beam.« less

Three-dimensional display technologies

PubMed Central

Geng, Jason

2014-01-01

The physical world around us is three-dimensional (3D), yet traditional display devices can show only two-dimensional (2D) flat images that lack depth (i.e., the third dimension) information. This fundamental restriction greatly limits our ability to perceive and to understand the complexity of real-world objects. Nearly 50% of the capability of the human brain is devoted to processing visual information [Human Anatomy & Physiology (Pearson, 2012)]. Flat images and 2D displays do not harness the brain’s power effectively. With rapid advances in the electronics, optics, laser, and photonics fields, true 3D display technologies are making their way into the marketplace. 3D movies, 3D TV, 3D mobile devices, and 3D games have increasingly demanded true 3D display with no eyeglasses (autostereoscopic). Therefore, it would be very beneficial to readers of this journal to have a systematic review of state-of-the-art 3D display technologies. PMID:25530827

Dynamic in vivo 3D atlantoaxial spine kinematics during upright rotation.

PubMed

Anderst, William; Rynearson, Bryan; West, Tyler; Donaldson, William; Lee, Joon

2017-07-26

Diagnosing dysfunctional atlantoaxial motion is challenging given limitations of current diagnostic imaging techniques. Three-dimensional imaging during upright functional motion may be useful in identifying dynamic instability not apparent on static imaging. Abnormal atlantoaxial motion has been linked to numerous pathologies including whiplash, cervicogenic headaches, C2 fractures, and rheumatoid arthritis. However, normal C1/C2 rotational kinematics under dynamic physiologic loading have not been previously reported owing to imaging difficulties. The objective of this study was to determine dynamic three-dimensional in vivo C1/C2 kinematics during upright axial rotation. Twenty young healthy adults performed full head rotation while seated within a biplane X-ray system while radiographs were collected at 30 images per second. Six degree-of-freedom kinematics were determined for C1 and C2 via a validated volumetric model-based tracking process. The maximum global head rotation (to one side) was 73.6±8.3°, whereas maximum C1 rotation relative to C2 was 36.8±6.7°. The relationship between C1/C2 rotation and head rotation was linear through midrange motion (±20° head rotation from neutral) in a nearly 1:1 ratio. Coupled rotation between C1 and C2 included 4.5±3.1° of flexion and 6.4±8.2° of extension, and 9.8±3.8° of contralateral bending. Translational motion of C1 relative to C2 was 7.8±1.5mm ipsilaterally, 2.2±1.2mm inferiorly, and 3.3±1.0mm posteriorly. We believe this is the first study describing 3D dynamic atlantoaxial kinematics under true physiologic conditions in healthy subjects. C1/C2 rotation accounts for approximately half of total head axial rotation. Additionally, C1 undergoes coupled flexion/extension and contralateral bending, in addition to inferior, lateral and posterior translation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Three-dimensional unstructured grid refinement and optimization using edge-swapping

NASA Technical Reports Server (NTRS)

Gandhi, Amar; Barth, Timothy

1993-01-01

This paper presents a three-dimensional (3-D) 'edge-swapping method based on local transformations. This method extends Lawson's edge-swapping algorithm into 3-D. The 3-D edge-swapping algorithm is employed for the purpose of refining and optimizing unstructured meshes according to arbitrary mesh-quality measures. Several criteria including Delaunay triangulations are examined. Extensions from two to three dimensions of several known properties of Delaunay triangulations are also discussed.

3D Imaging with Structured Illumination for Advanced Security Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Birch, Gabriel Carisle; Dagel, Amber Lynn; Kast, Brian A.

2015-09-01

Three-dimensional (3D) information in a physical security system is a highly useful dis- criminator. The two-dimensional data from an imaging systems fails to provide target dis- tance and three-dimensional motion vector, which can be used to reduce nuisance alarm rates and increase system effectiveness. However, 3D imaging devices designed primarily for use in physical security systems are uncommon. This report discusses an architecture favorable to physical security systems; an inexpensive snapshot 3D imaging system utilizing a simple illumination system. The method of acquiring 3D data, tests to understand illumination de- sign, and software modifications possible to maximize information gathering capabilitymore » are discussed.« less

Three dimensional measurement with an electrically tunable focused plenoptic camera

NASA Astrophysics Data System (ADS)

Lei, Yu; Tong, Qing; Xin, Zhaowei; Wei, Dong; Zhang, Xinyu; Liao, Jing; Wang, Haiwei; Xie, Changsheng

2017-03-01

A liquid crystal microlens array (LCMLA) with an arrayed microhole pattern electrode based on nematic liquid crystal materials using a fabrication method including traditional UV-photolithography and wet etching is presented. Its focusing performance is measured under different voltage signals applied between the electrodes of the LCMLA. The experimental outcome shows that the focal length of the LCMLA can be tuned easily by only changing the root mean square value of the voltage signal applied. The developed LCMLA is further integrated with a main lens and an imaging sensor to construct a LCMLA-based focused plenoptic camera (LCFPC) prototype. The focused range of the LCFPC can be shifted electrically along the optical axis of the imaging system. The principles and methods for acquiring several key parameters such as three dimensional (3D) depth, positioning, and motion expression are given. The depth resolution is discussed in detail. Experiments are carried out to obtain the static and dynamic 3D information of objects chosen.

Three dimensional measurement with an electrically tunable focused plenoptic camera.

PubMed

Lei, Yu; Tong, Qing; Xin, Zhaowei; Wei, Dong; Zhang, Xinyu; Liao, Jing; Wang, Haiwei; Xie, Changsheng

2017-03-01

A liquid crystal microlens array (LCMLA) with an arrayed microhole pattern electrode based on nematic liquid crystal materials using a fabrication method including traditional UV-photolithography and wet etching is presented. Its focusing performance is measured under different voltage signals applied between the electrodes of the LCMLA. The experimental outcome shows that the focal length of the LCMLA can be tuned easily by only changing the root mean square value of the voltage signal applied. The developed LCMLA is further integrated with a main lens and an imaging sensor to construct a LCMLA-based focused plenoptic camera (LCFPC) prototype. The focused range of the LCFPC can be shifted electrically along the optical axis of the imaging system. The principles and methods for acquiring several key parameters such as three dimensional (3D) depth, positioning, and motion expression are given. The depth resolution is discussed in detail. Experiments are carried out to obtain the static and dynamic 3D information of objects chosen.

Overview of Three-Dimensional Atomic-Resolution Holography and Imaging Techniques: Recent Advances in Local-Structure Science

NASA Astrophysics Data System (ADS)

Daimon, Hiroshi

2018-06-01

Local three-dimensional (3D) atomic arrangements without periodicity have not been able to be studied until recently. Recently, several holographies and related techniques have been developed to reveal the 3D atomic arrangement around specific atoms with no translational symmetry. This review gives an overview of these new local 3D atomic imaging techniques.

ENERGY DISSIPATION AND LANDAU DAMPING IN TWO- AND THREE-DIMENSIONAL PLASMA TURBULENCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Tak Chu; Howes, Gregory G.; Klein, Kristopher G.

Plasma turbulence is ubiquitous in space and astrophysical plasmas, playing an important role in plasma energization, but the physical mechanisms leading to dissipation of the turbulent energy remain to be definitively identified. Kinetic simulations in two dimensions (2D) have been extensively used to study the dissipation process. How the limitation to 2D affects energy dissipation remains unclear. This work provides a model of comparison between two- and three-dimensional (3D) plasma turbulence using gyrokinetic simulations; it also explores the dynamics of distribution functions during the dissipation process. It is found that both 2D and 3D nonlinear gyrokinetic simulations of a low-betamore » plasma generate electron velocity-space structures with the same characteristics as that of the linear Landau damping of Alfvén waves in a 3D linear simulation. The continual occurrence of the velocity-space structures throughout the turbulence simulations suggests that the action of Landau damping may be responsible for the turbulent energy transfer to electrons in both 2D and 3D, and makes possible the subsequent irreversible heating of the plasma through collisional smoothing of the velocity-space fluctuations. Although, in the 2D case where variation along the equilibrium magnetic field is absent, it may be expected that Landau damping is not possible, a common trigonometric factor appears in the 2D resonant denominator, leaving the resonance condition unchanged from the 3D case. The evolution of the 2D and 3D cases is qualitatively similar. However, quantitatively, the nonlinear energy cascade and subsequent dissipation is significantly slower in the 2D case.« less

Evaluating mental workload of two-dimensional and three-dimensional visualization for anatomical structure localization.

PubMed

Foo, Jung-Leng; Martinez-Escobar, Marisol; Juhnke, Bethany; Cassidy, Keely; Hisley, Kenneth; Lobe, Thom; Winer, Eliot

2013-01-01

Visualization of medical data in three-dimensional (3D) or two-dimensional (2D) views is a complex area of research. In many fields 3D views are used to understand the shape of an object, and 2D views are used to understand spatial relationships. It is unclear how 2D/3D views play a role in the medical field. Using 3D views can potentially decrease the learning curve experienced with traditional 2D views by providing a whole representation of the patient's anatomy. However, there are challenges with 3D views compared with 2D. This current study expands on a previous study to evaluate the mental workload associated with both 2D and 3D views. Twenty-five first-year medical students were asked to localize three anatomical structures--gallbladder, celiac trunk, and superior mesenteric artery--in either 2D or 3D environments. Accuracy and time were taken as the objective measures for mental workload. The NASA Task Load Index (NASA-TLX) was used as a subjective measure for mental workload. Results showed that participants viewing in 3D had higher localization accuracy and a lower subjective measure of mental workload, specifically, the mental demand component of the NASA-TLX. Results from this study may prove useful for designing curricula in anatomy education and improving training procedures for surgeons.

A three-dimensional virtual environment for modeling mechanical cardiopulmonary interactions.

PubMed

Kaye, J M; Primiano, F P; Metaxas, D N

1998-06-01

We have developed a real-time computer system for modeling mechanical physiological behavior in an interactive, 3-D virtual environment. Such an environment can be used to facilitate exploration of cardiopulmonary physiology, particularly in situations that are difficult to reproduce clinically. We integrate 3-D deformable body dynamics with new, formal models of (scalar) cardiorespiratory physiology, associating the scalar physiological variables and parameters with the corresponding 3-D anatomy. Our framework enables us to drive a high-dimensional system (the 3-D anatomical models) from one with fewer parameters (the scalar physiological models) because of the nature of the domain and our intended application. Our approach is amenable to modeling patient-specific circumstances in two ways. First, using CT scan data, we apply semi-automatic methods for extracting and reconstructing the anatomy to use in our simulations. Second, our scalar physiological models are defined in terms of clinically measurable, patient-specific parameters. This paper describes our approach, problems we have encountered and a sample of results showing normal breathing and acute effects of pneumothoraces.

Modeling the Epithelial Morphogenesis of Germ Band Retraction in Three Dimensions

NASA Astrophysics Data System (ADS)

McCleery, W. Tyler; Veldhuis, Jim; Brodland, G. Wayne; Crews, Sarah M.; Hutson, M. Shane

2015-03-01

Embryogenesis of higher-order organisms is driven by an intricate coordination of cellular mechanics. Mechanical analysis of certain developmental events, e.g., dorsal closure in the fruit fly D. melanogaster, has been sufficiently described using two-dimensional models. Here, we present a three-dimensional modeling technique to investigate germ band retraction (GBR) - a whole-embryo, irreducibly 3D morphogenetic event. At the start of GBR, the epithelial tissue known as the germ band is initially wrapped around the posterior end of an ellipsoidal fly embryo. This tissue then retracts as an adjacent epithelial tissue, the amnioserosa, simultaneously contracts. We hypothesize that proper GBR requires maintenance of cell-cell connectivity in the amnioserosa, as well as both cell and tissue topology on the embryo's ellipsoidal surface. The exact interfacial tensions are less important. We test the dynamic interactions between these two tissues on a 3D ellipsoidal last. To speed simulation run times and focus on the relevant tissues, epithelial cells are defined as polygons constrained to lie on the surface of the ellipsoidal last. These cells have adjustable parameters such as edge tensions and cell pressures. Tissue movements are simulated by balancing these dynamic cell-level forces with viscous resistance and allowing cells to exchange neighbors. This modeling approach helps elucidate the multicellular stress fields in normal and aberrant development, providing deeper insight into the mechanical interdependence of developing tissues.

Binary Colloidal Alloy Test-5: Three-Dimensional Melt

NASA Technical Reports Server (NTRS)

Yodh, Arjun G.

2008-01-01

Binary Colloidal Alloy Test - 5: Three-Dimensional Melt (BCAT-5-3DMelt) photographs initially randomized colloidal samples in microgravity to determine their resulting structure over time. BCAT-5-3D-Melt will allow the scientists to capture the kinetics (evolution) of their samples, as well as the final equilibrium state of each sample. BCAT-5-3D-Melt will look at the mechanisms of melting using three-dimensional temperature sensitive colloidal crystals. Results will help scientists develop fundamental physics concepts previously shadowed by the effects of gravity.

Optical monitoring of scoliosis by 3D medical laser scanner

NASA Astrophysics Data System (ADS)

Rodríguez-Quiñonez, Julio C.; Sergiyenko, Oleg Yu.; Preciado, Luis C. Basaca; Tyrsa, Vera V.; Gurko, Alexander G.; Podrygalo, Mikhail A.; Lopez, Moises Rivas; Balbuena, Daniel Hernandez

2014-03-01

Three dimensional recording of the human body surface or anatomical areas have gained importance in many medical applications. In this paper, our 3D Medical Laser Scanner is presented. It is based on the novel principle of dynamic triangulation. We analyze the method of operation, medical applications, orthopedically diseases as Scoliosis and the most common types of skin to employ the system the most proper way. It is analyzed a group of medical problems related to the application of optical scanning in optimal way. Finally, experiments are conducted to verify the performance of the proposed system and its method uncertainty.

A review on noise suppression and aberration compensation in holographic particle image velocimetry

NASA Astrophysics Data System (ADS)

Tamrin, K. F.; Rahmatullah, B.

2016-12-01

Understanding three-dimensional (3D) fluid flow behaviour is undeniably crucial in improving performance and efficiency in a wide range of applications in engineering and medical fields. Holographic particle image velocimetry (HPIV) is a potential tool to probe and characterize complex flow dynamics since it is a truly three-dimensional three-component measurement technique. The technique relies on the coherent light scattered by small seeding particles that are assumed to faithfully follow the flow for subsequent reconstruction of the same the event afterward. However, extraction of useful 3D displacement data from these particle images is usually aggravated by noise and aberration which are inherent within the optical system. Noise and aberration have been considered as major hurdles in HPIV in obtaining accurate particle image identification and its corresponding 3D position. Major contributions to noise include zero-order diffraction, out-of-focus particles, virtual image and emulsion grain scattering. Noise suppression is crucial to ensure that particle image can be distinctly differentiated from background noise while aberration compensation forms particle image with high integrity. This paper reviews a number of HPIV configurations that have been proposed to address these issues, summarizes the key findings and outlines a basis for follow-on research.

Quantification of turbulence and velocity in stenotic flow using spiral three-dimensional phase-contrast MRI.

PubMed

Petersson, Sven; Dyverfeldt, Petter; Sigfridsson, Andreas; Lantz, Jonas; Carlhäll, Carl-Johan; Ebbers, Tino

2016-03-01

Evaluate spiral three-dimensional (3D) phase contrast MRI for the assessment of turbulence and velocity in stenotic flow. A-stack-of-spirals 3D phase contrast MRI sequence was evaluated in vitro against a conventional Cartesian sequence. Measurements were made in a flow phantom with a 75% stenosis. Both spiral and Cartesian imaging were performed using different scan orientations and flow rates. Volume flow rate, maximum velocity and turbulent kinetic energy (TKE) were computed for both methods. Moreover, the estimated TKE was compared with computational fluid dynamics (CFD) data. There was good agreement between the turbulent kinetic energy from the spiral, Cartesian and CFD data. Flow rate and maximum velocity from the spiral data agreed well with Cartesian data. As expected, the short echo time of the spiral sequence resulted in less prominent displacement artifacts compared with the Cartesian sequence. However, both spiral and Cartesian flow rate estimates were sensitive to displacement when the flow was oblique to the encoding directions. Spiral 3D phase contrast MRI appears favorable for the assessment of stenotic flow. The spiral sequence was more than three times faster and less sensitive to displacement artifacts when compared with a conventional Cartesian sequence. © 2015 Wiley Periodicals, Inc.

Novel Visualization Approaches in Environmental Mineralogy

NASA Astrophysics Data System (ADS)

Anderson, C. D.; Lopano, C. L.; Hummer, D. R.; Heaney, P. J.; Post, J. E.; Kubicki, J. D.; Sofo, J. O.

2006-05-01

Communicating the complexities of atomic scale reactions between minerals and fluids is fraught with intrinsic challenges. For example, an increasing number of techniques are now available for the interrogation of dynamical processes at the mineral-fluid interface. However, the time-dependent behavior of atomic interactions between a solid and a liquid is often not adequately captured by two-dimensional line drawings or images. At the same time, the necessity for describing these reactions to general audiences is growing more urgent, as funding agencies are amplifying their encouragement to scientists to reach across disciplines and to justify their studies to public audiences. To overcome the shortcomings of traditional graphical representations, the Center for Environmental Kinetics Analysis is creating three-dimensional visualizations of experimental and simulated mineral reactions. These visualizations are then displayed on a stereo 3D projection system called the GeoWall. Made possible (and affordable) by recent improvements in computer and data projector technology, the GeoWall system uses a combination of computer software and hardware, polarizing filters and polarizing glasses, to present visualizations in true 3D. The three-dimensional views greatly improve comprehension of complex multidimensional data, and animations of time series foster better understanding of the underlying processes. The visualizations also offer an effective means to communicate the complexities of environmental mineralogy to colleagues, students and the public. Here we present three different kinds of datasets that demonstrate the effectiveness of the GeoWall in clarifying complex environmental reactions at the atomic scale. First, a time-resolved series of diffraction patterns obtained during the hydrothermal synthesis of metal oxide phases from precursor solutions can be viewed as a surface with interactive controls for peak scaling and color mapping. Second, the results of Rietveld analysis of cation exchange reactions in Mn oxides has provided three-dimensional difference Fourier maps. When stitched together in a temporal series, these offer an animated view of changes in atomic configurations during the process of exchange. Finally, molecular dynamical simulations are visualized as three-dimensional reactions between vibrating atoms in both the solid and the aqueous phases.

Comparison of two- and three-dimensional Navier-Stokes solutions with NASA experimental data for CAST-10 airfoil

NASA Technical Reports Server (NTRS)

Swanson, R. Charles; Radespiel, Rolf; Mccormick, V. Edward

1989-01-01

The two-dimensional (2-D) and three-dimensional Navier-Stokes equations are solved for flow over a NAE CAST-10 airfoil model. Recently developed finite-volume codes that apply a multistage time stepping scheme in conjunction with steady state acceleration techniques are used to solve the equations. Two-dimensional results are shown for flow conditions uncorrected and corrected for wind tunnel wall interference effects. Predicted surface pressures from 3-D simulations are compared with those from 2-D calculations. The focus of the 3-D computations is the influence of the sidewall boundary layers. Topological features of the 3-D flow fields are indicated. Lift and drag results are compared with experimental measurements.

Computational techniques to enable visualizing shapes of objects of extra spatial dimensions

NASA Astrophysics Data System (ADS)

Black, Don Vaughn, II

Envisioning extra dimensions beyond the three of common experience is a daunting challenge for three dimensional observers. Intuition relies on experience gained in a three dimensional environment. Gaining experience with virtual four dimensional objects and virtual three manifolds in four-space on a personal computer may provide the basis for an intuitive grasp of four dimensions. In order to enable such a capability for ourselves, it is first necessary to devise and implement a computationally tractable method to visualize, explore, and manipulate objects of dimension beyond three on the personal computer. A technology is described in this dissertation to convert a representation of higher dimensional models into a format that may be displayed in realtime on graphics cards available on many off-the-shelf personal computers. As a result, an opportunity has been created to experience the shape of four dimensional objects on the desktop computer. The ultimate goal has been to provide the user a tangible and memorable experience with mathematical models of four dimensional objects such that the user can see the model from any user selected vantage point. By use of a 4D GUI, an arbitrary convex hull or 3D silhouette of the 4D model can be rotated, panned, scrolled, and zoomed until a suitable dimensionally reduced view or Aspect is obtained. The 4D GUI then allows the user to manipulate a 3-flat hyperplane cutting tool to slice the model at an arbitrary orientation and position to extract or "pluck" an embedded 3D slice or "aspect" from the embedding four-space. This plucked 3D aspect can be viewed from all angles via a conventional 3D viewer using three multiple POV viewports, and optionally exported to a third party CAD viewer for further manipulation. Plucking and Manipulating the Aspect provides a tangible experience for the end-user in the same manner as any 3D Computer Aided Design viewing and manipulation tool does for the engineer or a 3D video game provides for the nascent student.

Three-dimensional cascaded system analysis of a 50 µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis.

PubMed

Zhao, C; Vassiljev, N; Konstantinidis, A C; Speller, R D; Kanicki, J

2017-03-07

High-resolution, low-noise x-ray detectors based on the complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been developed and proposed for digital breast tomosynthesis (DBT). In this study, we evaluated the three-dimensional (3D) imaging performance of a 50 µm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). The two-dimensional (2D) angle-dependent modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) were experimentally characterized and modeled using the cascaded system analysis at oblique incident angles up to 30°. The cascaded system model was extended to the 3D spatial frequency space in combination with the filtered back-projection (FBP) reconstruction method to calculate the 3D and in-plane MTF, NNPS and DQE parameters. The results demonstrate that the beam obliquity blurs the 2D MTF and DQE in the high spatial frequency range. However, this effect can be eliminated after FBP image reconstruction. In addition, impacts of the image acquisition geometry and detector parameters were evaluated using the 3D cascaded system analysis for DBT. The result shows that a wider projection angle range (e.g.  ±30°) improves the low spatial frequency (below 5 mm -1 ) performance of the CMOS APS detector. In addition, to maintain a high spatial resolution for DBT, a focal spot size of smaller than 0.3 mm should be used. Theoretical analysis suggests that a pixelated scintillator in combination with the 50 µm pixel pitch CMOS APS detector could further improve the 3D image resolution. Finally, the 3D imaging performance of the CMOS APS and an indirect amorphous silicon (a-Si:H) thin-film transistor (TFT) passive pixel sensor (PPS) detector was simulated and compared.

Three-dimensional cascaded system analysis of a 50 µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis

NASA Astrophysics Data System (ADS)

Zhao, C.; Vassiljev, N.; Konstantinidis, A. C.; Speller, R. D.; Kanicki, J.

2017-03-01

High-resolution, low-noise x-ray detectors based on the complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been developed and proposed for digital breast tomosynthesis (DBT). In this study, we evaluated the three-dimensional (3D) imaging performance of a 50 µm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). The two-dimensional (2D) angle-dependent modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) were experimentally characterized and modeled using the cascaded system analysis at oblique incident angles up to 30°. The cascaded system model was extended to the 3D spatial frequency space in combination with the filtered back-projection (FBP) reconstruction method to calculate the 3D and in-plane MTF, NNPS and DQE parameters. The results demonstrate that the beam obliquity blurs the 2D MTF and DQE in the high spatial frequency range. However, this effect can be eliminated after FBP image reconstruction. In addition, impacts of the image acquisition geometry and detector parameters were evaluated using the 3D cascaded system analysis for DBT. The result shows that a wider projection angle range (e.g.  ±30°) improves the low spatial frequency (below 5 mm-1) performance of the CMOS APS detector. In addition, to maintain a high spatial resolution for DBT, a focal spot size of smaller than 0.3 mm should be used. Theoretical analysis suggests that a pixelated scintillator in combination with the 50 µm pixel pitch CMOS APS detector could further improve the 3D image resolution. Finally, the 3D imaging performance of the CMOS APS and an indirect amorphous silicon (a-Si:H) thin-film transistor (TFT) passive pixel sensor (PPS) detector was simulated and compared.

Speckle-based three-dimensional velocity measurement using spatial filtering velocimetry.

PubMed

Iversen, Theis F Q; Jakobsen, Michael L; Hanson, Steen G

2011-04-10

We present an optical method for measuring the real-time three-dimensional (3D) translational velocity of a diffusely scattering rigid object observed through an imaging system. The method is based on a combination of the motion of random speckle patterns and regular fringe patterns. The speckle pattern is formed in the observation plane of the imaging system due to reflection from an area of the object illuminated by a coherent light source. The speckle pattern translates in response to in-plane translation of the object, and the presence of an angular offset reference wave coinciding with the speckle pattern in the observation plane gives rise to interference, resulting in a fringe pattern that translates in response to the out-of-plane translation of the object. Numerical calculations are performed to evaluate the dynamic properties of the intensity distribution and the response of realistic spatial filters designed to measure the three components of the object's translational velocity. Furthermore, experimental data are presented that demonstrate full 3D velocity measurement. © 2011 Optical Society of America

Invasive plants transform the three-dimensional structure of rain forests

PubMed Central

Asner, Gregory P.; Hughes, R. Flint; Vitousek, Peter M.; Knapp, David E.; Kennedy-Bowdoin, Ty; Boardman, Joseph; Martin, Roberta E.; Eastwood, Michael; Green, Robert O.

2008-01-01

Biological invasions contribute to global environmental change, but the dynamics and consequences of most invasions are difficult to assess at regional scales. We deployed an airborne remote sensing system that mapped the location and impacts of five highly invasive plant species across 221,875 ha of Hawaiian ecosystems, identifying four distinct ways that these species transform the three-dimensional (3D) structure of native rain forests. In lowland to montane forests, three invasive tree species replace native midcanopy and understory plants, whereas one understory invader excludes native species at the ground level. A fifth invasive nitrogen-fixing tree, in combination with a midcanopy alien tree, replaces native plants at all canopy levels in lowland forests. We conclude that this diverse array of alien plant species, each representing a different growth form or functional type, is changing the fundamental 3D structure of native Hawaiian rain forests. Our work also demonstrates how an airborne mapping strategy can identify and track the spread of certain invasive plant species, determine ecological consequences of their proliferation, and provide detailed geographic information to conservation and management efforts. PMID:18316720

Single-shot real-time three dimensional measurement based on hue-height mapping

NASA Astrophysics Data System (ADS)

Wan, Yingying; Cao, Yiping; Chen, Cheng; Fu, Guangkai; Wang, Yapin; Li, Chengmeng

2018-06-01

A single-shot three-dimensional (3D) measurement based on hue-height mapping is proposed. The color fringe pattern is encoded by three sinusoidal fringes with the same frequency but different shifting phase into red (R), green (G) and blue (B) color channels, respectively. It is found that the hue of the captured color fringe pattern on the reference plane maintains monotonic in one period even it has the color crosstalk. Thus, unlike the traditional color phase shifting technique, the hue information is utilized to decode the color fringe pattern and map to the pixels of the fringe displacement in the proposed method. Because the monotonicity of the hue is limited within one period, displacement unwrapping is proposed to obtain the continuous displacement that is finally used to map to the height distribution. This method directly utilizes the hue under the effect of color crosstalk for mapping the height so that no color calibration is involved. Also, as it requires only single shot deformed color fringe pattern, this method can be applied into the real-time or dynamic 3D measurements.

Anderson transition in a three-dimensional kicked rotor

NASA Astrophysics Data System (ADS)

Wang, Jiao; García-García, Antonio M.

2009-03-01

We investigate Anderson localization in a three-dimensional (3D) kicked rotor. By a finite-size scaling analysis we identify a mobility edge for a certain value of the kicking strength k=kc . For k>kc dynamical localization does not occur, all eigenstates are delocalized and the spectral correlations are well described by Wigner-Dyson statistics. This can be understood by mapping the kicked rotor problem onto a 3D Anderson model (AM) where a band of metallic states exists for sufficiently weak disorder. Around the critical region k≈kc we carry out a detailed study of the level statistics and quantum diffusion. In agreement with the predictions of the one parameter scaling theory (OPT) and with previous numerical simulations, the number variance is linear, level repulsion is still observed, and quantum diffusion is anomalous with ⟨p2⟩∝t2/3 . We note that in the 3D kicked rotor the dynamics is not random but deterministic. In order to estimate the differences between these two situations we have studied a 3D kicked rotor in which the kinetic term of the associated evolution matrix is random. A detailed numerical comparison shows that the differences between the two cases are relatively small. However in the deterministic case only a small set of irrational periods was used. A qualitative analysis of a much larger set suggests that deviations between the random and the deterministic kicked rotor can be important for certain choices of periods. Heuristically it is expected that localization effects will be weaker in a nonrandom potential since destructive interference will be less effective to arrest quantum diffusion. However we have found that certain choices of irrational periods enhance Anderson localization effects.

[3D Virtual Reality Laparoscopic Simulation in Surgical Education - Results of a Pilot Study].

PubMed

Kneist, W; Huber, T; Paschold, M; Lang, H

2016-06-01

The use of three-dimensional imaging in laparoscopy is a growing issue and has led to 3D systems in laparoscopic simulation. Studies on box trainers have shown differing results concerning the benefit of 3D imaging. There are currently no studies analysing 3D imaging in virtual reality laparoscopy (VRL). Five surgical fellows, 10 surgical residents and 29 undergraduate medical students performed abstract and procedural tasks on a VRL simulator using conventional 2D and 3D imaging in a randomised order. No significant differences between the two imaging systems were shown for students or medical professionals. Participants who preferred three-dimensional imaging showed significantly better results in 2D as wells as in 3D imaging. First results on three-dimensional imaging on box trainers showed different results. Some studies resulted in an advantage of 3D imaging for laparoscopic novices. This study did not confirm the superiority of 3D imaging over conventional 2D imaging in a VRL simulator. In the present study on 3D imaging on a VRL simulator there was no significant advantage for 3D imaging compared to conventional 2D imaging. Georg Thieme Verlag KG Stuttgart · New York.

Dynamic three-dimensional phase-contrast technique in MRI: application to complex flow analysis around the artificial heart valve

NASA Astrophysics Data System (ADS)

Kim, Soo Jeong; Lee, Dong Hyuk; Song, Inchang; Kim, Nam Gook; Park, Jae-Hyeung; Kim, JongHyo; Han, Man Chung; Min, Byong Goo

1998-07-01

Phase-contrast (PC) method of magnetic resonance imaging (MRI) has bee used for quantitative measurements of flow velocity and volume flow rate. It is a noninvasive technique which provides an accurate two-dimensional velocity image. Moreover, Phase Contrast Cine magnetic resonance imaging combines the flow dependent contrast of PC-MRI with the ability of cardiac cine imaging to produce images throughout the cardiac cycle. However, the accuracy of the data acquired from the single through-plane velocity encoding can be reduced by the effect of flow direction, because in many practical cases flow directions are not uniform throughout the whole region of interest. In this study, we present dynamic three-dimensional velocity vector mapping method using PC-MRI which can visualize the complex flow pattern through 3D volume rendered images displayed dynamically. The direction of velocity mapping can be selected along any three orthogonal axes. By vector summation, the three maps can be combined to form a velocity vector map that determines the velocity regardless of the flow direction. At the same time, Cine method is used to observe the dynamic change of flow. We performed a phantom study to evaluate the accuracy of the suggested PC-MRI in continuous and pulsatile flow measurement. Pulsatile flow wave form is generated by the ventricular assistant device (VAD), HEMO-PULSA (Biomedlab, Seoul, Korea). We varied flow velocity, pulsatile flow wave form, and pulsing rate. The PC-MRI-derived velocities were compared with Doppler-derived results. The velocities of the two measurements showed a significant linear correlation. Dynamic three-dimensional velocity vector mapping was carried out for two cases. First, we applied to the flow analysis around the artificial heart valve in a flat phantom. We could observe the flow pattern around the valve through the 3-dimensional cine image. Next, it is applied to the complex flow inside the polymer sac that is used as ventricle in totally implantable artificial heart (TAH). As a result we could observe the flow pattern around the valves of the sac, though complex flow can not be detected correctly in the conventional phase contrast method. In addition, we could calculate the cardiac output from TAH sac by quantitative measurement of the volume of flow across the outlet valve.

Fluid dynamics of flapping aquatic flight in the bird wrasse: three-dimensional unsteady computations with fin deformation.

PubMed

Ramamurti, Ravi; Sandberg, William C; Löhner, Rainald; Walker, Jeffrey A; Westneat, Mark W

2002-10-01

Many fishes that swim with the paired pectoral fins use fin-stroke parameters that produce thrust force from lift in a mechanism of underwater flight. These locomotor mechanisms are of interest to behavioral biologists, biomechanics researchers and engineers. In the present study, we performed the first three-dimensional unsteady computations of fish swimming with oscillating and deforming fins. The objective of these computations was to investigate the fluid dynamics of force production associated with the flapping aquatic flight of the bird wrasse Gomphosus varius. For this computational work, we used the geometry of the wrasse and its pectoral fin, and previously measured fin kinematics, as the starting points for computational investigation of three-dimensional (3-D) unsteady fluid dynamics. We performed a 3-D steady computation and a complete set of 3-D quasisteady computations for a range of pectoral fin positions and surface velocities. An unstructured, grid-based, unsteady Navier-Stokes solver with automatic adaptive remeshing was then used to compute the unsteady flow about the wrasse through several complete cycles of pectoral fin oscillation. The shape deformation of the pectoral fin throughout the oscillation was taken from the experimental kinematics. The pressure distribution on the body of the bird wrasse and its pectoral fins was computed and integrated to give body and fin forces which were decomposed into lift and thrust. The velocity field variation on the surface of the wrasse body, on the pectoral fins and in the near-wake was computed throughout the swimming cycle. We compared our computational results for the steady, quasi-steady and unsteady cases with the experimental data on axial and vertical acceleration obtained from the pectoral fin kinematics experiments. These comparisons show that steady state computations are incapable of describing the fluid dynamics of flapping fins. Quasi-steady state computations, with correct incorporation of the experimental kinematics, are useful when determining trends in force production, but do not provide accurate estimates of the magnitudes of the forces produced. By contrast, unsteady computations about the deforming pectoral fins using experimentally measured fin kinematics were found to give excellent agreement, both in the time history of force production throughout the flapping strokes and in the magnitudes of the generated forces.

Real-time dynamic display of registered 4D cardiac MR and ultrasound images using a GPU

NASA Astrophysics Data System (ADS)

Zhang, Q.; Huang, X.; Eagleson, R.; Guiraudon, G.; Peters, T. M.

2007-03-01

In minimally invasive image-guided surgical interventions, different imaging modalities, such as magnetic resonance imaging (MRI), computed tomography (CT), and real-time three-dimensional (3D) ultrasound (US), can provide complementary, multi-spectral image information. Multimodality dynamic image registration is a well-established approach that permits real-time diagnostic information to be enhanced by placing lower-quality real-time images within a high quality anatomical context. For the guidance of cardiac procedures, it would be valuable to register dynamic MRI or CT with intraoperative US. However, in practice, either the high computational cost prohibits such real-time visualization of volumetric multimodal images in a real-world medical environment, or else the resulting image quality is not satisfactory for accurate guidance during the intervention. Modern graphics processing units (GPUs) provide the programmability, parallelism and increased computational precision to begin to address this problem. In this work, we first outline our research on dynamic 3D cardiac MR and US image acquisition, real-time dual-modality registration and US tracking. Then we describe image processing and optimization techniques for 4D (3D + time) cardiac image real-time rendering. We also present our multimodality 4D medical image visualization engine, which directly runs on a GPU in real-time by exploiting the advantages of the graphics hardware. In addition, techniques such as multiple transfer functions for different imaging modalities, dynamic texture binding, advanced texture sampling and multimodality image compositing are employed to facilitate the real-time display and manipulation of the registered dual-modality dynamic 3D MR and US cardiac datasets.

Three-dimensional magnetophotonic crystals based on artificial opals

NASA Astrophysics Data System (ADS)

Baryshev, A. V.; Kodama, T.; Nishimura, K.; Uchida, H.; Inoue, M.

2004-06-01

We fabricated and experimentally investigated three-dimensional magnetophotonic crystals (3D MPCs) based on artificial opals. Opal samples with three-dimensional dielectric lattices were impregnated with different types of magnetic material. Magnetic and structural properties of 3D MPCs were studied by field emission scanning electron microscopy, x-ray diffraction analysis, and vibrating sample magnetometer. We have shown that magnetic materials synthesized in voids of opal lattices and the composites obtained have typical magnetic properties.

A theoretical and computational study of lithium-ion battery thermal management for electric vehicles using heat pipes

NASA Astrophysics Data System (ADS)

Greco, Angelo; Cao, Dongpu; Jiang, Xi; Yang, Hong

2014-07-01

A simplified one-dimensional transient computational model of a prismatic lithium-ion battery cell is developed using thermal circuit approach in conjunction with the thermal model of the heat pipe. The proposed model is compared to an analytical solution based on variable separation as well as three-dimensional (3D) computational fluid dynamics (CFD) simulations. The three approaches, i.e. the 1D computational model, analytical solution, and 3D CFD simulations, yielded nearly identical results for the thermal behaviours. Therefore the 1D model is considered to be sufficient to predict the temperature distribution of lithium-ion battery thermal management using heat pipes. Moreover, a maximum temperature of 27.6 °C was predicted for the design of the heat pipe setup in a distributed configuration, while a maximum temperature of 51.5 °C was predicted when forced convection was applied to the same configuration. The higher surface contact of the heat pipes allows a better cooling management compared to forced convection cooling. Accordingly, heat pipes can be used to achieve effective thermal management of a battery pack with confined surface areas.

A spatiotemporal-based scheme for efficient registration-based segmentation of thoracic 4-D MRI.

PubMed

Yang, Y; Van Reeth, E; Poh, C L; Tan, C H; Tham, I W K

2014-05-01

Dynamic three-dimensional (3-D) (four-dimensional, 4-D) magnetic resonance (MR) imaging is gaining importance in the study of pulmonary motion for respiratory diseases and pulmonary tumor motion for radiotherapy. To perform quantitative analysis using 4-D MR images, segmentation of anatomical structures such as the lung and pulmonary tumor is required. Manual segmentation of entire thoracic 4-D MRI data that typically contains many 3-D volumes acquired over several breathing cycles is extremely tedious, time consuming, and suffers high user variability. This requires the development of new automated segmentation schemes for 4-D MRI data segmentation. Registration-based segmentation technique that uses automatic registration methods for segmentation has been shown to be an accurate method to segment structures for 4-D data series. However, directly applying registration-based segmentation to segment 4-D MRI series lacks efficiency. Here we propose an automated 4-D registration-based segmentation scheme that is based on spatiotemporal information for the segmentation of thoracic 4-D MR lung images. The proposed scheme saved up to 95% of computation amount while achieving comparable accurate segmentations compared to directly applying registration-based segmentation to 4-D dataset. The scheme facilitates rapid 3-D/4-D visualization of the lung and tumor motion and potentially the tracking of tumor during radiation delivery.

Local invariants in non-ideal flows of neutral fluids and two-fluid plasmas

NASA Astrophysics Data System (ADS)

Zhu, Jian-Zhou

2018-03-01

The main objective is the locally invariant geometric object of any (magneto-)fluid dynamics with forcing and damping (nonideal), while more attention is paid to the untouched dynamical properties of two-fluid fashion. Specifically, local structures, beyond the well-known "frozen-in" to the barotropic flows of the generalized vorticities, of the two-fluid model of plasma flows are presented. More general non-barotropic situations are also considered. A modified Euler equation [T. Tao, "Finite time blowup for Lagrangian modifications of the three-dimensional Euler equation," Ann. PDE 2, 9 (2016)] is also accordingly analyzed and remarked from the angle of view of the two-fluid model, with emphasis on the local structures. The local constraints of high-order differential forms such as helicity, among others, find simple formulation for possible practices in modeling the dynamics. Thus, the Cauchy invariants equation [N. Besse and U. Frisch, "Geometric formulation of the Cauchy invariants for incompressible Euler flow in flat and curved spaces," J. Fluid Mech. 825, 412 (2017)] may be enabled to find applications in non-ideal flows. Some formal examples are offered to demonstrate the calculations, and particularly interestingly the two-dimensional-three-component (2D3C) or the 2D passive scalar problem presents that a locally invariant Θ = 2θζ, with θ and ζ being, respectively, the scalar value of the "vertical velocity" (or the passive scalar) and the "vertical vorticity," may be used as if it were the spatial density of the globally invariant helicity, providing a Lagrangian prescription to control the latter in some situations of studying its physical effects in rapidly rotating flows (ubiquitous in atmosphere of astrophysical objects) with marked 2D3C vortical modes or in purely 2D passive scalars.

Three-channel dynamic photometric stereo: a new method for 4D surface reconstruction and volume recovery

NASA Astrophysics Data System (ADS)

Schroeder, Walter; Schulze, Wolfram; Wetter, Thomas; Chen, Chi-Hsien

2008-08-01

Three-dimensional (3D) body surface reconstruction is an important field in health care. A popular method for this purpose is laser scanning. However, using Photometric Stereo (PS) to record lumbar lordosis and the surface contour of the back poses a viable alternative due to its lower costs and higher flexibility compared to laser techniques and other methods of three-dimensional body surface reconstruction. In this work, we extended the traditional PS method and proposed a new method for obtaining surface and volume data of a moving object. The principle of traditional Photometric Stereo uses at least three images of a static object taken under different light sources to obtain 3D information of the object. Instead of using normal light, the light sources in the proposed method consist of the RGB-Color-Model's three colors: red, green and blue. A series of pictures taken with a video camera can now be separated into the different color channels. Each set of the three images can then be used to calculate the surface normals as a traditional PS. This method waives the requirement that the object imaged must be kept still as in almost all the other body surface reconstruction methods. By putting two cameras opposite to a moving object and lighting the object with the colored light, the time-varying surface (4D) data can easily be calculated. The obtained information can be used in many medical fields such as rehabilitation, diabetes screening or orthopedics.

Boundary element modelling of dynamic behavior of piecewise homogeneous anisotropic elastic solids

NASA Astrophysics Data System (ADS)

Igumnov, L. A.; Markov, I. P.; Litvinchuk, S. Yu

2018-04-01

A traditional direct boundary integral equations method is applied to solve three-dimensional dynamic problems of piecewise homogeneous linear elastic solids. The materials of homogeneous parts are considered to be generally anisotropic. The technique used to solve the boundary integral equations is based on the boundary element method applied together with the Radau IIA convolution quadrature method. A numerical example of suddenly loaded 3D prismatic rod consisting of two subdomains with different anisotropic elastic properties is presented to verify the accuracy of the proposed formulation.

Embryonic stem cells growing in 3-dimensions shift from reliance on the substrate to each other for mechanical support.

PubMed

Teo, Ailing; Lim, Mayasari; Weihs, Daphne

2015-07-16

Embryonic stem cells (ESCs) grow into three-dimensional (3D) spheroid structures en-route to tissue growth. In vitro spheroids can be controllably induced on a two-dimensional (2D) substrate with high viability. Here we use a method for inducing pluripotent embryoid body (EB) formation on flat polyacrylamide gels while simultaneously evaluating the dynamic changes in the mechano-biology of the growing 3D spheroids. During colony growth in 3D, pluripotency is conserved while the spheroid-substrate interactions change significantly. We correlate colony-size, cell-applied traction-forces, and expressions of cell-surface molecules indicating cell-cell and cell-substrate interactions, while verifying pluripotency. We show that as the colony size increases with time, the stresses applied by the spheroid to the gel decrease in the 3D growing EBs; control cells growing in 2D-monolayers maintain unvarying forces. Concurrently, focal-adhesion mediated cell-substrate interactions give way to E-cadherin cell-cell connections, while pluripotency. The mechano-biological changes occurring in the growing embryoid body are required for stabilization of the growing pluripotent 3D-structure, and can affect its potential uses including differentiation. This could enable development of more effective expansion, differentiation, and separation approaches for clinical purposes. Copyright © 2015 Elsevier Ltd. All rights reserved.

GRID3D-v2: An updated version of the GRID2D/3D computer program for generating grid systems in complex-shaped three-dimensional spatial domains

NASA Technical Reports Server (NTRS)

Steinthorsson, E.; Shih, T. I-P.; Roelke, R. J.

1991-01-01

In order to generate good quality systems for complicated three-dimensional spatial domains, the grid-generation method used must be able to exert rather precise controls over grid-point distributions. Several techniques are presented that enhance control of grid-point distribution for a class of algebraic grid-generation methods known as the two-, four-, and six-boundary methods. These techniques include variable stretching functions from bilinear interpolation, interpolating functions based on tension splines, and normalized K-factors. The techniques developed in this study were incorporated into a new version of GRID3D called GRID3D-v2. The usefulness of GRID3D-v2 was demonstrated by using it to generate a three-dimensional grid system in the coolent passage of a radial turbine blade with serpentine channels and pin fins.

In Situ Three-Dimensional Reciprocal-Space Mapping of Diffuse Scattering Intensity Distribution and Data Analysis for Precursor Phenomenon in Shape-Memory Alloy

NASA Astrophysics Data System (ADS)

Cheng, Tian-Le; Ma, Fengde D.; Zhou, Jie E.; Jennings, Guy; Ren, Yang; Jin, Yongmei M.; Wang, Yu U.

2012-01-01

Diffuse scattering contains rich information on various structural disorders, thus providing a useful means to study the nanoscale structural deviations from the average crystal structures determined by Bragg peak analysis. Extraction of maximal information from diffuse scattering requires concerted efforts in high-quality three-dimensional (3D) data measurement, quantitative data analysis and visualization, theoretical interpretation, and computer simulations. Such an endeavor is undertaken to study the correlated dynamic atomic position fluctuations caused by thermal vibrations (phonons) in precursor state of shape-memory alloys. High-quality 3D diffuse scattering intensity data around representative Bragg peaks are collected by using in situ high-energy synchrotron x-ray diffraction and two-dimensional digital x-ray detector (image plate). Computational algorithms and codes are developed to construct the 3D reciprocal-space map of diffuse scattering intensity distribution from the measured data, which are further visualized and quantitatively analyzed to reveal in situ physical behaviors. Diffuse scattering intensity distribution is explicitly formulated in terms of atomic position fluctuations to interpret the experimental observations and identify the most relevant physical mechanisms, which help set up reduced structural models with minimal parameters to be efficiently determined by computer simulations. Such combined procedures are demonstrated by a study of phonon softening phenomenon in precursor state and premartensitic transformation of Ni-Mn-Ga shape-memory alloy.

Waterlike anomalies in a two-dimensional core-softened potential

NASA Astrophysics Data System (ADS)

Bordin, José Rafael; Barbosa, Marcia C.

2018-02-01

We investigate the structural, thermodynamic, and dynamic behavior of a two-dimensional (2D) core-corona system using Langevin dynamics simulations. The particles are modeled by employing a core-softened potential which exhibits waterlike anomalies in three dimensions. In previous studies in a quasi-2D system a new region in the pressure versus temperature phase diagram of structural anomalies was observed. Here we show that for the two-dimensional case two regions in the pressure versus temperature phase diagram with structural, density, and diffusion anomalies are observed. Our findings indicate that, while the anomalous region at lower densities is due the competition between the two length scales in the potential at higher densities, the anomalous region is related to the reentrance of the melting line.

Assessment of the facial features and chin development of fetuses with use of serial three-dimensional sonography and the mandibular size monogram in a Chinese population.

PubMed

Tsai, Meng-Yin; Lan, Kuo-Chung; Ou, Chia-Yo; Chen, Jen-Huang; Chang, Shiuh-Young; Hsu, Te-Yao

2004-02-01

Our purpose was to evaluate whether the application of serial three-dimensional (3D) sonography and the mandibular size monogram can allow observation of dynamic changes in facial features, as well as chin development in utero. The mandibular size monogram has been established through a cross-sectional study involving 183 fetal images. The serial changes of facial features and chin development are assessed in a cohort study involving 40 patients. The monogram reveals that the Biparietal distance (BPD)/Mandibular body length (MBL) ratio is gradually decreased with the advance of gestational age. The cohort study conducted with serial 3D sonography shows the same tendency. Both the images and the results of paired-samples t test (P<.001) statistical analysis suggest that the fetuses develop wider chins and broader facial features in later weeks. The serial 3D sonography and mandibular size monogram display disproportionate growth of the fetal head and chin that leads to changes in facial features in late gestation. This fact must be considered when we evaluate fetuses at risk for development of micrognathia.

Lagrangian transport near perturbed periodic lines in three-dimensional unsteady flows

NASA Astrophysics Data System (ADS)

Speetjens, Michel

2015-11-01

Periodic lines formed by continuous strings of periodic points are key organizing entities in the Lagrangian flow topology of certain three-dimensional (3D) time-periodic flows. Such lines generically consist of elliptic and/or hyperbolic points and thus give rise to 3D flow topologies made up of families of concentric closed trajectories embedded in chaotic regions. Weak perturbation destroys the periodic lines and causes said trajectories to coalesce into families of concentric tubes. However, emergence of isolated periodic points near the disintegrating periodic lines and/or partitioning of the original lines into elliptic and hyperbolic segments interrupt the tube formation. This yields incomplete tubes that interact with the (chaotic) environment through their open ends, resulting in intricate and essentially 3D flow topologies These phenomena have been observed in various realistic flows yet the underlying mechanisms are to date only partially understood. This study deepens insight into the (perturbed) Lagrangian dynamics of these flows by way of a linearized representation of the equations of motion near the periodic lines. Predictions on the basis of this investigation are in full (qualitative) agreement with observed behavior in the actual flows

Holographic intravital microscopy for 2-D and 3-D imaging intact circulating blood cells in microcapillaries of live mice

NASA Astrophysics Data System (ADS)

Kim, Kyoohyun; Choe, Kibaek; Park, Inwon; Kim, Pilhan; Park, Yongkeun

2016-09-01

Intravital microscopy is an essential tool that reveals behaviours of live cells under conditions close to natural physiological states. So far, although various approaches for imaging cells in vivo have been proposed, most require the use of labelling and also provide only qualitative imaging information. Holographic imaging approach based on measuring the refractive index distributions of cells, however, circumvent these problems and offer quantitative and label-free imaging capability. Here, we demonstrate in vivo two- and three-dimensional holographic imaging of circulating blood cells in intact microcapillaries of live mice. The measured refractive index distributions of blood cells provide morphological and biochemical properties including three-dimensional cell shape, haemoglobin concentration, and haemoglobin contents at the individual cell level. With the present method, alterations in blood flow dynamics in live healthy and sepsis-model mice were also investigated.

Improved depth perception with three-dimensional auxiliary display and computer generated three-dimensional panoramic overviews in robot-assisted laparoscopy

PubMed Central

Wieringa, Fokko P.; Bouma, Henri; Eendebak, Pieter T.; van Basten, Jean-Paul A.; Beerlage, Harrie P.; Smits, Geert A. H. J.; Bos, Jelte E.

2014-01-01

Abstract. In comparison to open surgery, endoscopic surgery offers impaired depth perception and narrower field-of-view. To improve depth perception, the Da Vinci robot offers three-dimensional (3-D) video on the console for the surgeon but not for assistants, although both must collaborate. We improved the shared perception of the whole surgical team by connecting live 3-D monitors to all three available Da Vinci generations, probed user experience after two years by questionnaire, and compared time measurements of a predefined complex interaction task performed with a 3-D monitor versus two-dimensional. Additionally, we investigated whether the complex mental task of reconstructing a 3-D overview from an endoscopic video can be performed by a computer and shared among users. During the study, 925 robot-assisted laparoscopic procedures were performed in three hospitals, including prostatectomies, cystectomies, and nephrectomies. Thirty-one users participated in our questionnaire. Eighty-four percent preferred 3-D monitors and 100% reported spatial-perception improvement. All participating urologists indicated quicker performance of tasks requiring delicate collaboration (e.g., clip placement) when assistants used 3-D monitors. Eighteen users participated in a timing experiment during a delicate cooperation task in vitro. Teamwork was significantly (40%) faster with the 3-D monitor. Computer-generated 3-D reconstructions from recordings offered very wide interactive panoramas with educational value, although the present embodiment is vulnerable to movement artifacts. PMID:26158026

Orthogonality measurements for multidimensional chromatography in three and higher dimensional separations.

PubMed

Schure, Mark R; Davis, Joe M

2017-11-10

Orthogonality metrics (OMs) for three and higher dimensional separations are proposed as extensions of previously developed OMs, which were used to evaluate the zone utilization of two-dimensional (2D) separations. These OMs include correlation coefficients, dimensionality, information theory metrics and convex-hull metrics. In a number of these cases, lower dimensional subspace metrics exist and can be readily calculated. The metrics are used to interpret previously generated experimental data. The experimental datasets are derived from Gilar's peptide data, now modified to be three dimensional (3D), and a comprehensive 3D chromatogram from Moore and Jorgenson. The Moore and Jorgenson chromatogram, which has 25 identifiable 3D volume elements or peaks, displayed good orthogonality values over all dimensions. However, OMs based on discretization of the 3D space changed substantially with changes in binning parameters. This example highlights the importance in higher dimensions of having an abundant number of retention times as data points, especially for methods that use discretization. The Gilar data, which in a previous study produced 21 2D datasets by the pairing of 7 one-dimensional separations, was reinterpreted to produce 35 3D datasets. These datasets show a number of interesting properties, one of which is that geometric and harmonic means of lower dimensional subspace (i.e., 2D) OMs correlate well with the higher dimensional (i.e., 3D) OMs. The space utilization of the Gilar 3D datasets was ranked using OMs, with the retention times of the datasets having the largest and smallest OMs presented as graphs. A discussion concerning the orthogonality of higher dimensional techniques is given with emphasis on molecular diversity in chromatographic separations. In the information theory work, an inconsistency is found in previous studies of orthogonality using the 2D metric often identified as %O. A new choice of metric is proposed, extended to higher dimensions, characterized by mixes of ordered and random retention times, and applied to the experimental datasets. In 2D, the new metric always equals or exceeds the original one. However, results from both the original and new methods are given. Copyright © 2017 Elsevier B.V. All rights reserved.

Importance of preoperative imaging with 64-row three-dimensional multidetector computed tomography for safer video-assisted thoracic surgery in lung cancer.

PubMed

Akiba, Tadashi; Marushima, Hideki; Harada, Junta; Kobayashi, Susumu; Morikawa, Toshiaki

2009-01-01

Video-assisted thoracic surgery (VATS) has recently been adopted for complicated anatomical lung resections. During these thoracoscopic procedures, surgeons view the operative field on a two-dimensional (2-D) video monitor and cannot palpate the organ directly, thus frequently encountering anatomical difficulties. This study aimed to estimate the usefulness of preoperative three-dimensional (3-D) imaging of thoracic organs. We compared the preoperative 64-row three-dimensional multidetector computed tomography (3DMDCT) findings of lung cancer-affected thoracic organs to the operative findings. In comparison to the operative findings, the branches of pulmonary arteries, veins, and bronchi were well defined in the 3D-MDCT images of 27 patients. 3D-MDCT imaging is useful for preoperatively understanding the individual thoracic anatomy in lung cancer surgery. This modality can therefore contribute to safer anatomical pulmonary operations, especially in VATS.

Development of a system for acquiring, reconstructing, and visualizing three-dimensional ultrasonic angiograms

NASA Astrophysics Data System (ADS)

Edwards, Warren S.; Ritchie, Cameron J.; Kim, Yongmin; Mack, Laurence A.

1995-04-01

We have developed a three-dimensional (3D) imaging system using power Doppler (PD) ultrasound (US). This system can be used for visualizing and analyzing the vascular anatomy of parenchymal organs. To create the 3D PD images, we acquired a series of two-dimensional PD images from a commercial US scanner and recorded the position and orientation of each image using a 3D magnetic position sensor. Three-dimensional volumes were reconstructed using specially designed software and then volume rendered for display. We assessed the feasibility and geometric accuracy of our system with various flow phantoms. The system was then tested on a volunteer by scanning a transplanted kidney. The reconstructed volumes of the flow phantom contained less than 1 mm of geometric distortion and the 3D images of the transplanted kidney depicted the segmental, arcuate, and interlobar vessels.

3D analysis of vortical structures in an abdominal aortic aneurysm by stereoscopic PIV

NASA Astrophysics Data System (ADS)

Deplano, Valérie; Guivier-Curien, Carine; Bertrand, Eric

2016-11-01

The present work presents an experimental in vitro three-dimensional analysis of the flow dynamics in an abdominal aortic aneurysm (AAA) through stereoscopic particle image velocimetry (SPIV) measurements. The experimental set-up mimics the pathophysiological context involving a shear thinning blood analogue fluid, compliant AAA and aorto-iliac bifurcation walls and controlled inlet and outlet flow rate and pressure waveforms as well as working fluid temperature. SPIV was carefully calibrated and conducted to assess the three velocity components in the AAA volume. For the first time in the literature, the 3D vortex ring genesis, propagation, and vanishing in the AAA bulge are experimentally described and quantified. In comparison with classical 2-component PIV measurements (2C PIV), the third component of the velocity vector was shown to be of importance in such a geometry, especially, during the deceleration phase of the flow rate. The 3D velocity magnitude reached up more than 20 % of the 2D one showing that 2C PIV are definitively not accurate enough to provide a complete description of flow behaviour in an AAA. In addition to potential clinical implications of a full 3D vortex ring description in AAA evolution, the 3D in vitro experimental quantification of the flow dynamics carried out in the present study offers an interesting tool for the validation of fluid-structure interaction numerical studies dealing with AAA.

[Application of three-dimensional printing technique in orthopaedics].

PubMed

Luo, Qiang; Lau, Tak Wing; Fang, Xinshuo; Leung, Frankie

2014-03-01

To review the current progress of three-dimensional (3-D) printing technique in the clinical practice, its limitations and prospects. The recent publications associated with the clinical application of 3-D printing technique in the field of surgery, especially in orthopaedics were extensively reviewed. Currently, 3-D printing technique has been applied in orthopaedic surgery to aid diagnosis, make operative plans, and produce personalized prosthesis or implants. 3-D printing technique is a promising technique in clinical application.

An update on intraoperative three-dimensional transesophageal echocardiography

PubMed Central

2017-01-01

Transesophageal echocardiography (TEE) was first used routinely in the operating rooms in the 1980s to facilitate surgical decision-making. Since then, TEE has evolved from the standard two-dimensional (2D) exam to include focused real-time three-dimensional (RT-3D) imaging both inside and outside the operating rooms. Improved spatial and temporal resolution due to technological advances has expedited surgical interventions in diseased valves. 3D imaging has also emerged as a crucial adjunct in percutaneous interventions for structural heart disease. With continued advancement in software, RT-3D TEE will continue to impact perioperative decisions. PMID:28540070

A web-based instruction module for interpretation of craniofacial cone beam CT anatomy.

PubMed

Hassan, B A; Jacobs, R; Scarfe, W C; Al-Rawi, W T

2007-09-01

To develop a web-based module for learner instruction in the interpretation and recognition of osseous anatomy on craniofacial cone-beam CT (CBCT) images. Volumetric datasets from three CBCT systems were acquired (i-CAT, NewTom 3G and AccuiTomo FPD) for various subjects using equipment-specific scanning protocols. The datasets were processed using multiple software to provide two-dimensional (2D) multiplanar reformatted (MPR) images (e.g. sagittal, coronal and axial) and three-dimensional (3D) visual representations (e.g. maximum intensity projection, minimum intensity projection, ray sum, surface and volume rendering). Distinct didactic modules which illustrate the principles of CBCT systems, guided navigation of the volumetric dataset, and anatomic correlation of 3D models and 2D MPR graphics were developed using a hybrid combination of web authoring and image analysis techniques. Interactive web multimedia instruction was facilitated by the use of dynamic highlighting and labelling, and rendered video illustrations, supplemented with didactic textual material. HTML coding and Java scripting were heavily implemented for the blending of the educational modules. An interactive, multimedia educational tool for visualizing the morphology and interrelationships of osseous craniofacial anatomy, as depicted on CBCT MPR and 3D images, was designed and implemented. The present design of a web-based instruction module may assist radiologists and clinicians in learning how to recognize and interpret the craniofacial anatomy of CBCT based images more efficiently.

Creation of three-dimensional craniofacial standards from CBCT images

NASA Astrophysics Data System (ADS)

Subramanyan, Krishna; Palomo, Martin; Hans, Mark

2006-03-01

Low-dose three-dimensional Cone Beam Computed Tomography (CBCT) is becoming increasingly popular in the clinical practice of dental medicine. Two-dimensional Bolton Standards of dentofacial development are routinely used to identify deviations from normal craniofacial anatomy. With the advent of CBCT three dimensional imaging, we propose a set of methods to extend these 2D Bolton Standards to anatomically correct surface based 3D standards to allow analysis of morphometric changes seen in craniofacial complex. To create 3D surface standards, we have implemented series of steps. 1) Converting bi-plane 2D tracings into set of splines 2) Converting the 2D splines curves from bi-plane projection into 3D space curves 3) Creating labeled template of facial and skeletal shapes and 4) Creating 3D average surface Bolton standards. We have used datasets from patients scanned with Hitachi MercuRay CBCT scanner providing high resolution and isotropic CT volume images, digitized Bolton Standards from age 3 to 18 years of lateral and frontal male, female and average tracings and converted them into facial and skeletal 3D space curves. This new 3D standard will help in assessing shape variations due to aging in young population and provide reference to correct facial anomalies in dental medicine.

A defocus-information-free autostereoscopic three-dimensional (3D) digital reconstruction method using direct extraction of disparity information (DEDI)

NASA Astrophysics Data System (ADS)

Li, Da; Cheung, Chifai; Zhao, Xing; Ren, Mingjun; Zhang, Juan; Zhou, Liqiu

2016-10-01

Autostereoscopy based three-dimensional (3D) digital reconstruction has been widely applied in the field of medical science, entertainment, design, industrial manufacture, precision measurement and many other areas. The 3D digital model of the target can be reconstructed based on the series of two-dimensional (2D) information acquired by the autostereoscopic system, which consists multiple lens and can provide information of the target from multiple angles. This paper presents a generalized and precise autostereoscopic three-dimensional (3D) digital reconstruction method based on Direct Extraction of Disparity Information (DEDI) which can be used to any transform autostereoscopic systems and provides accurate 3D reconstruction results through error elimination process based on statistical analysis. The feasibility of DEDI method has been successfully verified through a series of optical 3D digital reconstruction experiments on different autostereoscopic systems which is highly efficient to perform the direct full 3D digital model construction based on tomography-like operation upon every depth plane with the exclusion of the defocused information. With the absolute focused information processed by DEDI method, the 3D digital model of the target can be directly and precisely formed along the axial direction with the depth information.

Menaquinone-4 enhances osteogenic potential of human amniotic fluid mesenchymal stem cells cultured in 2D and 3D dynamic culture systems.

PubMed

Mandatori, Domitilla; Penolazzi, Letizia; Pipino, Caterina; Di Tomo, Pamela; Di Silvestre, Sara; Di Pietro, Natalia; Trevisani, Sara; Angelozzi, Marco; Ucci, Mariangela; Piva, Roberta; Pandolfi, Assunta

2018-02-01

Menaquinones, also known as Vitamin K2 family, regulate calcium homeostasis in a 'bone-vascular cross-talk' and recently received particular attention for their positive effect on bone formation. Given that the correlation between menaquinones and bone metabolism to date is still unclear, the objective of our study was to investigate the possible role of menaquinone-4 (MK-4), an isoform of the menaquinones family, in the modulation of osteogenesis. For this reason, we used a model of human amniotic fluid mesenchymal stem cells (hAFMSCs) cultured both in two-dimensional (2D) and three-dimensional (3D; RCCS™bioreactor) in vitro culture systems. Furthermore, to mimic the 'bone remodelling unit' in vitro, hAFMSCs were co-cultured in the 3D system with human monocyte cells (hMCs) as osteoclast precursors. The results showed that in a conventional 2D culture system, hAFMSCs were responsive to the MK-4, which significantly improved the osteogenic process through γ-glutamyl carboxylase-dependent pathway. The same results were obtained in the 3D dynamic system where MK-4 treatment supported the osteoblast-like formation promoting the extracellular bone matrix deposition and the expression of the osteogenic-related proteins (alkaline phosphatase, osteopontin, collagen type-1 and osteocalcin). Notably, when the hAFMSCs were co-cultured in a 3D dynamic system with the hMCs, the presence of MK-4 supported the cellular aggregate formation as well as the osteogenic function of hAFMSCs, but negatively affected the osteoclastogenic process. Taken together, our results demonstrate that MK-4 supported the aggregate formation of hAFMSCs and increased the osteogenic functions. Specifically, our data could help to optimize bone regenerative medicine combining cell-based approaches with MK-4 treatment. Copyright © 2017 John Wiley & Sons, Ltd.

Management of three-dimensional intrafraction motion through real-time DMLC tracking.

PubMed

Sawant, Amit; Venkat, Raghu; Srivastava, Vikram; Carlson, David; Povzner, Sergey; Cattell, Herb; Keall, Paul

2008-05-01

Tumor tracking using a dynamic multileaf collimator (DMLC) represents a promising approach for intrafraction motion management in thoracic and abdominal cancer radiotherapy. In this work, we develop, empirically demonstrate, and characterize a novel 3D tracking algorithm for real-time, conformal, intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT)-based radiation delivery to targets moving in three dimensions. The algorithm obtains real-time information of target location from an independent position monitoring system and dynamically calculates MLC leaf positions to account for changes in target position. Initial studies were performed to evaluate the geometric accuracy of DMLC tracking of 3D target motion. In addition, dosimetric studies were performed on a clinical linac to evaluate the impact of real-time DMLC tracking for conformal, step-and-shoot (S-IMRT), dynamic (D-IMRT), and VMAT deliveries to a moving target. The efficiency of conformal and IMRT delivery in the presence of tracking was determined. Results show that submillimeter geometric accuracy in all three dimensions is achievable with DMLC tracking. Significant dosimetric improvements were observed in the presence of tracking for conformal and IMRT deliveries to moving targets. A gamma index evaluation with a 3%-3 mm criterion showed that deliveries without DMLC tracking exhibit between 1.7 (S-IMRT) and 4.8 (D-IMRT) times more dose points that fail the evaluation compared to corresponding deliveries with tracking. The efficiency of IMRT delivery, as measured in the lab, was observed to be significantly lower in case of tracking target motion perpendicular to MLC leaf travel compared to motion parallel to leaf travel. Nevertheless, these early results indicate that accurate, real-time DMLC tracking of 3D tumor motion is feasible and can potentially result in significant geometric and dosimetric advantages leading to more effective management of intrafraction motion.

Camera pose estimation for augmented reality in a small indoor dynamic scene

NASA Astrophysics Data System (ADS)

Frikha, Rawia; Ejbali, Ridha; Zaied, Mourad

2017-09-01

Camera pose estimation remains a challenging task for augmented reality (AR) applications. Simultaneous localization and mapping (SLAM)-based methods are able to estimate the six degrees of freedom camera motion while constructing a map of an unknown environment. However, these methods do not provide any reference for where to insert virtual objects since they do not have any information about scene structure and may fail in cases of occlusion of three-dimensional (3-D) map points or dynamic objects. This paper presents a real-time monocular piece wise planar SLAM method using the planar scene assumption. Using planar structures in the mapping process allows rendering virtual objects in a meaningful way on the one hand and improving the precision of the camera pose and the quality of 3-D reconstruction of the environment by adding constraints on 3-D points and poses in the optimization process on the other hand. We proposed to benefit from the 3-D planes rigidity motion in the tracking process to enhance the system robustness in the case of dynamic scenes. Experimental results show that using a constrained planar scene improves our system accuracy and robustness compared with the classical SLAM systems.

Three-Dimensional Localization of Single Molecules for Super-Resolution Imaging and Single-Particle Tracking

PubMed Central

von Diezmann, Alex; Shechtman, Yoav; Moerner, W. E.

2017-01-01

Single-molecule super-resolution fluorescence microscopy and single-particle tracking are two imaging modalities that illuminate the properties of cells and materials on spatial scales down to tens of nanometers, or with dynamical information about nanoscale particle motion in the millisecond range, respectively. These methods generally use wide-field microscopes and two-dimensional camera detectors to localize molecules to much higher precision than the diffraction limit. Given the limited total photons available from each single-molecule label, both modalities require careful mathematical analysis and image processing. Much more information can be obtained about the system under study by extending to three-dimensional (3D) single-molecule localization: without this capability, visualization of structures or motions extending in the axial direction can easily be missed or confused, compromising scientific understanding. A variety of methods for obtaining both 3D super-resolution images and 3D tracking information have been devised, each with their own strengths and weaknesses. These include imaging of multiple focal planes, point-spread-function engineering, and interferometric detection. These methods may be compared based on their ability to provide accurate and precise position information of single-molecule emitters with limited photons. To successfully apply and further develop these methods, it is essential to consider many practical concerns, including the effects of optical aberrations, field-dependence in the imaging system, fluorophore labeling density, and registration between different color channels. Selected examples of 3D super-resolution imaging and tracking are described for illustration from a variety of biological contexts and with a variety of methods, demonstrating the power of 3D localization for understanding complex systems. PMID:28151646

Algorithm for planning a double-jaw orthognathic surgery using a computer-aided surgical simulation (CASS) protocol. Part 2: three-dimensional cephalometry

PubMed Central

Xia, J. J.; Gateno, J.; Teichgraeber, J. F.; Yuan, P.; Li, J.; Chen, K.-C.; Jajoo, A.; Nicol, M.; Alfi, D. M.

2015-01-01

Three-dimensional (3D) cephalometry is not as simple as just adding a ‘third’ dimension to a traditional two-dimensional cephalometric analysis. There are more complex issues in 3D analysis. These include how reference frames are created, how size, position, orientation and shape are measured, and how symmetry is assessed. The main purpose of this article is to present the geometric principles of 3D cephalometry. In addition, the Gateno–Xia cephalometric analysis is presented; this is the first 3D cephalometric analysis to observe these principles. PMID:26573563

The application of CFD to the modelling of fires in complex geometries

NASA Astrophysics Data System (ADS)

Burns, A. D.; Clarke, D. S.; Guilbert, P.; Jones, I. P.; Simcox, S.; Wilkes, N. S.

The application of Computational Fluid Dynamics (CFD) to industrial safety is a challenging activity. In particular it involves the interaction of several different physical processes, including turbulence, combustion, radiation, buoyancy, compressible flow and shock waves in complex three-dimensional geometries. In addition, there may be multi-phase effects arising, for example, from sprinkler systems for extinguishing fires. The FLOW3D software (1-3) from Computational Fluid Dynamics Services (CFDS) is in widespread use in industrial safety problems, both within AEA Technology, and also by CFDS's commercial customers, for example references (4-13). This paper discusses some other applications of FLOW3D to safety problems. These applications illustrate the coupling of the gas flows with radiation models and combustion models, particularly for complex geometries where simpler radiation models are not applicable.

Feasibility of free-breathing dynamic contrast-enhanced MRI of gastric cancer using a golden-angle radial stack-of-stars VIBE sequence: comparison with the conventional contrast-enhanced breath-hold 3D VIBE sequence.

PubMed

Li, Huan-Huan; Zhu, Hui; Yue, Lei; Fu, Yi; Grimm, Robert; Stemmer, Alto; Fu, Cai-Xia; Peng, Wei-Jun

2018-05-01

To investigate the feasibility and diagnostic value of free-breathing, radial, stack-of-stars three-dimensional (3D) gradient echo (GRE) sequence ("golden angle") on dynamic contrast-enhanced (DCE) MRI of gastric cancer. Forty-three gastric cancer patients were divided into cooperative and uncooperative groups. Respiratory fluctuation was observed using an abdominal respiratory gating sensor. Those who breath-held for more than 15 s were placed in the cooperative group and the remainder in the uncooperative group. The 3-T MRI scanning protocol included 3D GRE and conventional breath-hold VIBE (volume-interpolated breath-hold examination) sequences, comparing images quantitatively and qualitatively. DCE-MRI parameters from VIBE images of normal gastric wall and malignant lesions were compared. For uncooperative patients, 3D GRE scored higher qualitatively, and had higher SNRs (signal-to-noise ratios) and CNRs (contrast-to-noise ratios) than conventional VIBE quantitatively. Though 3D GRE images scored lower in qualitative parameters compared with conventional VIBE for cooperative patients, it provided images with fewer artefacts. DCE parameters differed significantly between normal gastric wall and lesions, with higher Ve (extracellular volume) and lower Kep (reflux constant) in gastric cancer. The free-breathing, golden-angle, radial stack-of-stars 3D GRE technique is feasible for DCE-MRI of gastric cancer. Dynamic enhanced images can be used for quantitative analysis of this malignancy. • Golden-angle radial stack-of-stars VIBE aids gastric cancer MRI diagnosis. • The 3D GRE technique is suitable for patients unable to suspend respiration. • Method scored higher in the qualitative evaluation for uncooperative patients. • The technique produced images with fewer artefacts than conventional VIBE sequence. • Dynamic enhanced images can be used for quantitative analysis of gastric cancer.

[Application of three-dimensional digital technology in the diagnosis and treatment planning in orthodontics].

PubMed

Bai, Y X

2016-06-01

Three-dimensional(3D)digital technology has been widely used in the field of orthodontics in clinical examination, diagnosis, treatment and curative effect evaluation. 3D digital technology greatly improves the accuracy of diagnosis and treatment, and provides effective means for personalized orthodontic treatment. This review focuses on the application of 3D digital technology in the field of orthodontics.

A micromechanical constitutive model for the dynamic response of brittle materials "Dynamic response of marble"

NASA Astrophysics Data System (ADS)

Haberman, Keith

2001-07-01

A micromechanically based constitutive model for the dynamic inelastic behavior of brittle materials, specifically "Dionysus-Pentelicon marble" with distributed microcracking is presented. Dionysus-Pentelicon marble was used in the construction of the Parthenon, in Athens, Greece. The constitutive model is a key component in the ability to simulate this historic explosion and the preceding bombardment form cannon fire that occurred at the Parthenon in 1678. Experiments were performed by Rosakis (1999) that characterized the static and dynamic response of this unique material. A micromechanical constitutive model that was previously successfully used to model the dynamic response of granular brittle materials is presented. The constitutive model was fitted to the experimental data for marble and reproduced the experimentally observed basic uniaxial dynamic behavior quite well. This micromechanical constitutive model was then implemented into the three dimensional nonlinear lagrangain finite element code Dyna3d(1998). Implementing this methodology into the three dimensional nonlinear dynamic finite element code allowed the model to be exercised on several preliminary impact experiments. During future simulations, the model is to be used in conjunction with other numerical techniques to simulate projectile impact and blast loading on the Dionysus-Pentelicon marble and on the structure of the Parthenon.

Automated Reconstruction of Three-Dimensional Fish Motion, Forces, and Torques

PubMed Central

Voesenek, Cees J.; Pieters, Remco P. M.; van Leeuwen, Johan L.

2016-01-01

Fish can move freely through the water column and make complex three-dimensional motions to explore their environment, escape or feed. Nevertheless, the majority of swimming studies is currently limited to two-dimensional analyses. Accurate experimental quantification of changes in body shape, position and orientation (swimming kinematics) in three dimensions is therefore essential to advance biomechanical research of fish swimming. Here, we present a validated method that automatically tracks a swimming fish in three dimensions from multi-camera high-speed video. We use an optimisation procedure to fit a parameterised, morphology-based fish model to each set of video images. This results in a time sequence of position, orientation and body curvature. We post-process this data to derive additional kinematic parameters (e.g. velocities, accelerations) and propose an inverse-dynamics method to compute the resultant forces and torques during swimming. The presented method for quantifying 3D fish motion paves the way for future analyses of swimming biomechanics. PMID:26752597

Image volume analysis of omnidirectional parallax regular-polyhedron three-dimensional displays.

PubMed

Kim, Hwi; Hahn, Joonku; Lee, Byoungho

2009-04-13

Three-dimensional (3D) displays having regular-polyhedron structures are proposed and their imaging characteristics are analyzed. Four types of conceptual regular-polyhedron 3D displays, i.e., hexahedron, octahedron, dodecahedron, and icosahedrons, are considered. In principle, regular-polyhedron 3D display can present omnidirectional full parallax 3D images. Design conditions of structural factors such as viewing angle of facet panel and observation distance for 3D display with omnidirectional full parallax are studied. As a main issue, image volumes containing virtual 3D objects represented by the four types of regular-polyhedron displays are comparatively analyzed.

Validation of a rapid, semiautomatic image analysis tool for measurement of gastric accommodation and emptying by magnetic resonance imaging

PubMed Central

Dixit, Sudeepa; Fox, Mark; Pal, Anupam

2014-01-01

Magnetic resonance imaging (MRI) has advantages for the assessment of gastrointestinal structures and functions; however, processing MRI data is time consuming and this has limited uptake to a few specialist centers. This study introduces a semiautomatic image processing system for rapid analysis of gastrointestinal MRI. For assessment of simpler regions of interest (ROI) such as the stomach, the system generates virtual images along arbitrary planes that intersect the ROI edges in the original images. This generates seed points that are joined automatically to form contours on each adjacent two-dimensional image and reconstructed in three dimensions (3D). An alternative thresholding approach is available for rapid assessment of complex structures like the small intestine. For assessment of dynamic gastrointestinal function, such as gastric accommodation and emptying, the initial 3D reconstruction is used as reference to process adjacent image stacks automatically. This generates four-dimensional (4D) reconstructions of dynamic volume change over time. Compared with manual processing, this semiautomatic system reduced the user input required to analyze a MRI gastric emptying study (estimated 100 vs. 10,000 mouse clicks). This analysis was not subject to variation in volume measurements seen between three human observers. In conclusion, the image processing platform presented processed large volumes of MRI data, such as that produced by gastric accommodation and emptying studies, with minimal user input. 3D and 4D reconstructions of the stomach and, potentially, other gastrointestinal organs are produced faster and more accurately than manual methods. This system will facilitate the application of MRI in gastrointestinal research and clinical practice. PMID:25540229

Modeling of methanol decomposition on Pt/CeO2/ZrO2 catalyst in a packed bed microreactor

NASA Astrophysics Data System (ADS)

Pohar, Andrej; Belavič, Darko; Dolanc, Gregor; Hočevar, Stanko

2014-06-01

Methanol decomposition on Pt/CeO2/ZrO2 catalyst is studied inside a packed bed microreactor in the temperature range of 300-380 °C. The microreactor is fabricated using low-temperature co-fired ceramic (LTCC) technology, which is well suited for the production of relatively complex three-dimensional structures. It is packed with 2 wt% Pt-CeO2 catalyst, which is deposited onto ZrO2 spherical particles. A 1D mathematical model, which incorporates diffusion, convection and mass transfer through the boundary layer to the catalyst particles, as well as a 3D computational fluid dynamics model, are developed to describe the methanol decomposition process inside the packed bed. The microreactor exhibits reliable operation and no catalyst deactivation was observed during three months of experimentation. A comparison between the 1D mathematical model and the 3D model, considering the full 3D geometry of the microreactor is made and the differences between the models are identified and evaluated.

Two-photon polymerization of a three dimensional structure using beams with orbital angular momentum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Shi-Jie; Li, Yan, E-mail: li@pku.edu.cn; Liu, Zhao-Pei

The focus of a beam with orbital angular momentum exhibits internal structure instead of an elliptical intensity distribution of a Gaussian beam, and the superposition of Gauss-Laguerre beams realized by two-dimensional phase modulation can generate a complex three-dimensional (3D) focus. By taking advantage of the flexibility of this 3D focus tailoring, we have fabricated a 3D microstructure with high resolution by two-photon polymerization with a single exposure. Furthermore, we have polymerized an array of double-helix structures that demonstrates optical chirality.

Application of State-Space Smoothing to fMRI Data for Calculation of Lagged Transinformation between Human Brain Activations

NASA Astrophysics Data System (ADS)

Watanabe, Jobu

2009-09-01

Mutual information can be given a directional sense by introducing a time lag in one of the variables. In an author's previous study, to investigate the network dynamics of human brain regions, lagged transinformation (LTI) was introduced using time delayed mutual information. The LTI makes it possible to quantify the time course of dynamic information transfer between regions in the temporal domain. The LTI was applied to functional magnetic resonance imaging (fMRI) data involved in neural processing of the transformation and comparison from three-dimensional (3D) visual information to a two-dimensional (2D) location to calculate directed information flows between the activated brain regions. In the present study, for more precise estimation of LTI, Kalman filter smoothing was applied to the same fMRI data. Because the smoothing method exploits the full length of the time series data for the estimation, its application increases the precision. Large information flows were found from the bilateral prefrontal cortices to the parietal cortices. The results suggest that information of the 3D images stored as working memory was retrieved and transferred from the prefrontal cortices to the parietal cortices for comparison with information of the 2D images.

Principles of three-dimensional printing and clinical applications within the abdomen and pelvis.

PubMed

Bastawrous, Sarah; Wake, Nicole; Levin, Dmitry; Ripley, Beth

2018-04-04

Improvements in technology and reduction in costs have led to widespread interest in three-dimensional (3D) printing. 3D-printed anatomical models contribute to personalized medicine, surgical planning, and education across medical specialties, and these models are rapidly changing the landscape of clinical practice. A physical object that can be held in one's hands allows for significant advantages over standard two-dimensional (2D) or even 3D computer-based virtual models. Radiologists have the potential to play a significant role as consultants and educators across all specialties by providing 3D-printed models that enhance clinical care. This article reviews the basics of 3D printing, including how models are created from imaging data, clinical applications of 3D printing within the abdomen and pelvis, implications for education and training, limitations, and future directions.

Design and characterization of a new bioreactor for continuous ultra-slow uniaxial distraction of a three-dimensional scaffold-free stem cell culture.

PubMed

Weiss, S; Henle, P; Roth, W; Bock, R; Boeuf, S; Richter, W

2011-01-01

A computer controlled dynamic bioreactor for continuous ultra-slow uniaxial distraction of a scaffold-free three-dimensional (3D) mesenchymal stem cell pellet culture was designed to investigate the influence of stepless tensile strain on behavior of distinct primary cells like osteoblasts, chondroblasts, or stem cells without the influence of an artificial culture matrix. The main advantages of this device include the following capabilities: (1) Application of uniaxial ultra-slow stepless distraction within a range of 0.5-250 μm/h and real-time control of the distraction distance with high accuracy (mean error -3.4%); (2) tension strain can be applied on a 3D cell culture within a standard CO(2) -incubator without use of an artificial culture matrix; (3) possibility of histological investigation without loss of distraction; (4) feasibility of molecular analysis on RNA and protein level. This is the first report on a distraction device capable of applying continuous tensile strain to a scaffold-free 3D cell culture within physiological ranges of motion comparable to distraction ostegenesis in vivo. We expect the newly designed microdistraction device to increase our understanding on the regulatory mechanisms of mechanical strains on the metabolism of stem cells. Copyright © 2010 American Institute of Chemical Engineers (AIChE).

Revisiting the Al/Al₂O₃ interface: coherent interfaces and misfit accommodation.

PubMed

Pilania, Ghanshyam; Thijsse, Barend J; Hoagland, Richard G; Lazić, Ivan; Valone, Steven M; Liu, Xiang-Yang

2014-03-27

We study the coherent and semi-coherent Al/α-Al2O3 interfaces using molecular dynamics simulations with a mixed, metallic-ionic atomistic model. For the coherent interfaces, both Al-terminated and O-terminated nonstoichiometric interfaces have been studied and their relative stability has been established. To understand the misfit accommodation at the semi-coherent interface, a 1-dimensional (1D) misfit dislocation model and a 2-dimensional (2D) dislocation network model have been studied. For the latter case, our analysis reveals an interface dislocation structure with a network of three sets of parallel dislocations, each with pure-edge character, giving rise to a pattern of coherent and stacking-fault-like regions at the interface. Structural relaxation at elevated temperatures leads to a further change of the dislocation pattern, which can be understood in terms of a competition between the stacking fault energy and the dislocation interaction energy at the interface. Our results are expected to serve as an input for the subsequent dislocation dynamics models to understand and predict the macroscopic mechanical behavior of Al/α-Al2O3 composite heterostructures.

Three-dimensional imaging of dislocation propagation during crystal growth and dissolution

PubMed Central

Schenk, Anna S.; Kim, Yi-Yeoun; Kulak, Alexander N.; Campbell, James M.; Nisbet, Gareth; Meldrum, Fiona C.; Robinson, Ian K.

2015-01-01

Atomic level defects such as dislocations play key roles in determining the macroscopic properties of crystalline materials 1,2. Their effects range from increased chemical reactivity 3,4 to enhanced mechanical properties 5,6. Dislocations have been widely studied using traditional techniques such as X-ray diffraction and optical imaging. Recent advances have enabled atomic force microscopy to study single dislocations 7 in two-dimensions (2D), while transmission electron microscopy (TEM) can now visualise strain fields in three-dimensions (3D) with near atomic resolution 8–10. However, these techniques cannot offer 3D imaging of the formation or movement of dislocations during dynamic processes. Here, we describe how Bragg Coherent Diffraction Imaging (BCDI) 11,12 can be used to visualize in 3D, the entire network of dislocations present within an individual calcite crystal during repeated growth and dissolution cycles. These investigations demonstrate the potential of BCDI for studying the mechanisms underlying the response of crystalline materials to external stimuli. PMID:26030304

A novel method to acquire 3D data from serial 2D images of a dental cast

NASA Astrophysics Data System (ADS)

Yi, Yaxing; Li, Zhongke; Chen, Qi; Shao, Jun; Li, Xinshe; Liu, Zhiqin

2007-05-01

This paper introduced a newly developed method to acquire three-dimensional data from serial two-dimensional images of a dental cast. The system consists of a computer and a set of data acquiring device. The data acquiring device is used to take serial pictures of the a dental cast; an artificial neural network works to translate two-dimensional pictures to three-dimensional data; then three-dimensional image can reconstruct by the computer. The three-dimensional data acquiring of dental casts is the foundation of computer-aided diagnosis and treatment planning in orthodontics.

Anisotropic evolution of 5D Friedmann-Robertson-Walker spacetime

DOE Office of Scientific and Technical Information (OSTI.GOV)

Middleton, Chad A.; Stanley, Ethan

2011-10-15

We examine the time evolution of the five-dimensional Einstein field equations subjected to a flat, anisotropic Robertson-Walker metric, where the 3D and higher-dimensional scale factors are allowed to dynamically evolve at different rates. By adopting equations of state relating the 3D and higher-dimensional pressures to the density, we obtain an exact expression relating the higher-dimensional scale factor to a function of the 3D scale factor. This relation allows us to write the Friedmann-Robertson-Walker field equations exclusively in terms of the 3D scale factor, thus yielding a set of 4D effective Friedmann-Robertson-Walker field equations. We examine the effective field equations inmore » the general case and obtain an exact expression relating a function of the 3D scale factor to the time. This expression involves a hypergeometric function and cannot, in general, be inverted to yield an analytical expression for the 3D scale factor as a function of time. When the hypergeometric function is expanded for small and large arguments, we obtain a generalized treatment of the dynamical compactification scenario of Mohammedi [Phys. Rev. D 65, 104018 (2002)] and the 5D vacuum solution of Chodos and Detweiler [Phys. Rev. D 21, 2167 (1980)], respectively. By expanding the hypergeometric function near a branch point, we obtain the perturbative solution for the 3D scale factor in the small time regime. This solution exhibits accelerated expansion, which, remarkably, is independent of the value of the 4D equation of state parameter w. This early-time epoch of accelerated expansion arises naturally out of the anisotropic evolution of 5D spacetime when the pressure in the extra dimension is negative and offers a possible alternative to scalar field inflationary theory.« less

A 3-D Finite-Volume Non-hydrostatic Icosahedral Model (NIM)

NASA Astrophysics Data System (ADS)

Lee, Jin

2014-05-01

The Nonhydrostatic Icosahedral Model (NIM) formulates the latest numerical innovation of the three-dimensional finite-volume control volume on the quasi-uniform icosahedral grid suitable for ultra-high resolution simulations. NIM's modeling goal is to improve numerical accuracy for weather and climate simulations as well as to utilize the state-of-art computing architecture such as massive parallel CPUs and GPUs to deliver routine high-resolution forecasts in timely manner. NIM dynamic corel innovations include: * A local coordinate system remapped spherical surface to plane for numerical accuracy (Lee and MacDonald, 2009), * Grid points in a table-driven horizontal loop that allow any horizontal point sequence (A.E. MacDonald, et al., 2010), * Flux-Corrected Transport formulated on finite-volume operators to maintain conservative positive definite transport (J.-L, Lee, ET. Al., 2010), *Icosahedral grid optimization (Wang and Lee, 2011), * All differentials evaluated as three-dimensional finite-volume integrals around the control volume. The three-dimensional finite-volume solver in NIM is designed to improve pressure gradient calculation and orographic precipitation over complex terrain. NIM dynamical core has been successfully verified with various non-hydrostatic benchmark test cases such as internal gravity wave, and mountain waves in Dynamical Cores Model Inter-comparisons Projects (DCMIP). Physical parameterizations suitable for NWP are incorporated into NIM dynamical core and successfully tested with multimonth aqua-planet simulations. Recently, NIM has started real data simulations using GFS initial conditions. Results from the idealized tests as well as real-data simulations will be shown in the conference.

A simple three dimensional wide-angle beam propagation method

NASA Astrophysics Data System (ADS)

Ma, Changbao; van Keuren, Edward

2006-05-01

The development of three dimensional (3-D) waveguide structures for chip scale planar lightwave circuits (PLCs) is hampered by the lack of effective 3-D wide-angle (WA) beam propagation methods (BPMs). We present a simple 3-D wide-angle beam propagation method (WA-BPM) using Hoekstra’s scheme along with a new 3-D wave equation splitting method. The applicability, accuracy and effectiveness of our method are demonstrated by applying it to simulations of wide-angle beam propagation and comparing them with analytical solutions.

A simple three dimensional wide-angle beam propagation method.

PubMed

Ma, Changbao; Van Keuren, Edward

2006-05-29

The development of three dimensional (3-D) waveguide structures for chip scale planar lightwave circuits (PLCs) is hampered by the lack of effective 3-D wide-angle (WA) beam propagation methods (BPMs). We present a simple 3-D wide-angle beam propagation method (WA-BPM) using Hoekstra's scheme along with a new 3-D wave equation splitting method. The applicability, accuracy and effectiveness of our method are demonstrated by applying it to simulations of wide-angle beam propagation and comparing them with analytical solutions.

Three-dimensional cell culture models for investigating human viruses.

PubMed

He, Bing; Chen, Guomin; Zeng, Yi

2016-10-01

Three-dimensional (3D) culture models are physiologically relevant, as they provide reproducible results, experimental flexibility and can be adapted for high-throughput experiments. Moreover, these models bridge the gap between traditional two-dimensional (2D) monolayer cultures and animal models. 3D culture systems have significantly advanced basic cell science and tissue engineering, especially in the fields of cell biology and physiology, stem cell research, regenerative medicine, cancer research, drug discovery, and gene and protein expression studies. In addition, 3D models can provide unique insight into bacteriology, virology, parasitology and host-pathogen interactions. This review summarizes and analyzes recent progress in human virological research with 3D cell culture models. We discuss viral growth, replication, proliferation, infection, virus-host interactions and antiviral drugs in 3D culture models.

Three-dimensional interpretation of TEM soundings

NASA Astrophysics Data System (ADS)

Barsukov, P. O.; Fainberg, E. B.

2013-07-01

We describe the approach to the interpretation of electromagnetic (EM) sounding data which iteratively adjusts the three-dimensional (3D) model of the environment by local one-dimensional (1D) transformations and inversions and reconstructs the geometrical skeleton of the model. The final 3D inversion is carried out with the minimal number of the sought parameters. At each step of the interpretation, the model of the medium is corrected according to the geological information. The practical examples of the suggested method are presented.

Modelling of river plume dynamics in Öre estuary (Baltic Sea) with Telemac-3D hydrodynamic model

NASA Astrophysics Data System (ADS)

Sokolov, Alexander

2016-04-01

The main property of river plumes is their buoyancy, fresh water discharged by rivers is less dense than the receiving, saline waters. To study the processes of plume formation in case of river discharge into a brackish estuary where salinity is low (3.5 - 5 psu) a three dimensional hydrodynamic model was applied to the Öre estuary in the Baltic Sea. This estuary is a small fjord-like bay in the north part of the Baltic Sea. Size of the bay is about 8 by 8 km with maximum depth of 35 metres. River Öre has a small average freshwater discharge of 35 m3/s. But in spring during snowmelt the discharge can be many times higher. For example, in April 2015 the discharge increased from 8 m3/s to 160 m3/s in 18 days. To study river plume dynamics a finite element based three dimensional baroclinic model TELEMAC - 3D is used. The TELEMAC modelling suite is developed by the National Laboratory of Hydraulics and Environment (LNHE) of Electricité de France (EDF). Modelling domain was approximated by an unstructured mesh with element size varies from 50 to 500 m. In vertical direction a sigma-coordinate with 20 layers was used. Open sea boundary conditions were obtained from the Baltic Sea model HIROMB-BOOS using COPERNICUS marine environment monitoring service. Comparison of modelling results with observations obtained by BONUS COCOA project's field campaign in Öre estuary in 2015 shows that the model plausible simulate river plume dynamics. Modelling of age of freshwater is also discussed. This work resulted from the BONUS COCOA project was supported by BONUS (Art 185), funded jointly by the EU and the Swedish Research Council Formas.

3D printing functional materials and devices (Conference Presentation)

NASA Astrophysics Data System (ADS)

McAlpine, Michael C.

2017-05-01

The development of methods for interfacing high performance functional devices with biology could impact regenerative medicine, smart prosthetics, and human-machine interfaces. Indeed, the ability to three-dimensionally interweave biological and functional materials could enable the creation of devices possessing unique geometries, properties, and functionalities. Yet, most high quality functional materials are two dimensional, hard and brittle, and require high crystallization temperatures for maximal performance. These properties render the corresponding devices incompatible with biology, which is three-dimensional, soft, stretchable, and temperature sensitive. We overcome these dichotomies by: 1) using 3D printing and scanning for customized, interwoven, anatomically accurate device architectures; 2) employing nanotechnology as an enabling route for overcoming mechanical discrepancies while retaining high performance; and 3) 3D printing a range of soft and nanoscale materials to enable the integration of a diverse palette of high quality functional nanomaterials with biology. 3D printing is a multi-scale platform, allowing for the incorporation of functional nanoscale inks, the printing of microscale features, and ultimately the creation of macroscale devices. This three-dimensional blending of functional materials and `living' platforms may enable next-generation 3D printed devices.

Accurate facade feature extraction method for buildings from three-dimensional point cloud data considering structural information

NASA Astrophysics Data System (ADS)

Wang, Yongzhi; Ma, Yuqing; Zhu, A.-xing; Zhao, Hui; Liao, Lixia

2018-05-01

Facade features represent segmentations of building surfaces and can serve as a building framework. Extracting facade features from three-dimensional (3D) point cloud data (3D PCD) is an efficient method for 3D building modeling. By combining the advantages of 3D PCD and two-dimensional optical images, this study describes the creation of a highly accurate building facade feature extraction method from 3D PCD with a focus on structural information. The new extraction method involves three major steps: image feature extraction, exploration of the mapping method between the image features and 3D PCD, and optimization of the initial 3D PCD facade features considering structural information. Results show that the new method can extract the 3D PCD facade features of buildings more accurately and continuously. The new method is validated using a case study. In addition, the effectiveness of the new method is demonstrated by comparing it with the range image-extraction method and the optical image-extraction method in the absence of structural information. The 3D PCD facade features extracted by the new method can be applied in many fields, such as 3D building modeling and building information modeling.

Multifunctional Bioreactor System for Human Intestine Tissues

PubMed Central

2017-01-01

The three-dimensional (3D) cultivation of intestinal cells and tissues in dynamic bioreactor systems to represent in vivo intestinal microenvironments is essential for developing regenerative medicine treatments for intestinal diseases. We have previously developed in vitro human intestinal tissue systems using a 3D porous silk scaffold system with intestinal architectures and topographical features for the adhesion, growth, and differentiation of intestinal cells under static culture conditions. In this study, we designed and fabricated a multifunctional bioreactor system that incorporates pre-epithelialized 3D silk scaffolds in a dynamic culture environment for in vitro engineering of human intestine tissues. The bioreactor system allows for control of oxygen levels in perfusion fluids (aerobic simulated intestinal fluid (SIF), microaerobic SIF, and anaerobic SIF), while ensuring control over the mechanical and chemical microenvironments present in native human intestines. The bioreactor system also enables 3D cell culture with spatial separation and cultivation of cocultured epithelial and stromal cells. Preliminary functional analysis of tissues housed in the bioreactor demonstrated that the 3D tissue constructs survived and maintained typical phenotypes of intestinal epithelium, including epithelial tight junction formation, intestinal biomarker expression, microvilli formation, and mucus secretion. The unique combination of a dynamic bioreactor and 3D intestinal constructs offers utility for engineering human intestinal tissues for the study of intestinal diseases and discovery options for new treatments. PMID:29333491

Viewing region maximization of an integral floating display through location adjustment of viewing window.

PubMed

Kim, Joowhan; Min, Sung-Wook; Lee, Byoungho

2007-10-01

Integral floating display is a recently proposed three-dimensional (3D) display method which provides a dynamic 3D image in the vicinity to an observer. It has a viewing window only through which correct 3D images can be observed. However, the positional difference between the viewing window and the floating image causes limited viewing zone in integral floating system. In this paper, we provide the principle and experimental results of the location adjustment of the viewing window of the integral floating display system by modifying the elemental image region for integral imaging. We explain the characteristics of the viewing window and propose how to move the viewing window to maximize the viewing zone.

Three-Dimensional Display Technologies for Anatomical Education: A Literature Review

ERIC Educational Resources Information Center

Hackett, Matthew; Proctor, Michael

2016-01-01

Anatomy is a foundational component of biological sciences and medical education and is important for a variety of clinical tasks. To augment current curriculum and improve students' spatial knowledge of anatomy, many educators, anatomists, and researchers use three-dimensional (3D) visualization technologies. This article reviews 3D display…

Nondestructive analysis of three-dimensional objects using a fluid displacement method

USDA-ARS?s Scientific Manuscript database

Quantification of three-dimensional (3-D) objects has been a real challenge in agricultural, hydrological and environmental studies. We designed and tested a method that is capable of quantifying 3-D objects using measurements of fluid displacement. The device consists of a stand that supports a mov...

Three-Dimensional Engineered High Fidelity Normal Human Lung Tissue-Like Assemblies (TLA) as Targets for Human Respiratory Virus Infections

NASA Technical Reports Server (NTRS)

Goodwin, T. J.; Deatly, A. M.; Suderman, M. T.; Lin, Y.-H.; Chen, W.; Gupta, C. K.; Randolph, V. B.; Udem, S. A.

2003-01-01

Unlike traditional two-dimensional (2D) cell cultures, three-dimensional (3D) tissue-like assemblies (TLA) (Goodwin et aI, 1992, 1993, 2000 and Nickerson et aI. , 2001,2002) offer high organ fidelity with the potential to emulate the infective dynamics of viruses and bacteria in vivo. Thus, utilizing NASA micro gravity Rotating Wall Vessel (RWV) technology, in vitro human broncho-epithelial (HBE) TLAs were engineered to mimic in vivo tissue for study of human respiratory viruses. These 3D HBE TLAs were propagated from a human broncho-tracheal cell line with a mesenchymal component (HBTC) as the foundation matrix and either an adult human broncho-epithelial cell (BEAS-2B) or human neonatal epithelial cell (16HBE140-) as the overlying element. Resulting TLAs share several characteristic features with in vivo human respiratory epithelium including tight junctions, desmosomes and cilia (SEM, TEM). The presence of epithelium and specific lung epithelium markers furthers the contention that these HBE cells differentiate into TLAs paralleling in vivo tissues. A time course of infection of these 3D HBE TLAs with human respiratory syncytial virus (hRSV) wild type A2 strain, indicates that virus replication and virus budding are supported and manifested by increasing virus titer and detection of membrane-bound F and G glycoproteins. Infected 3D HBE TLAs remain intact for up to 12 days compared to infected 2D cultures that are destroyed in 2-3 days. Infected cells show an increased vacuolation and cellular destruction (by transmission electron microscopy) by day 9; whereas, uninfected cells remain robust and morphologically intact. Therefore, the 3D HBE TLAs mimic aspects of human respiratory epithelium providing a unique opportunity to analyze, for the first time, simulated in vivo viral infection independent of host immune response.

GEO3D - Three-Dimensional Computer Model of a Ground Source Heat Pump System

DOE Data Explorer

James Menart

2013-06-07

This file is the setup file for the computer program GEO3D. GEO3D is a computer program written by Jim Menart to simulate vertical wells in conjunction with a heat pump for ground source heat pump (GSHP) systems. This is a very detailed three-dimensional computer model. This program produces detailed heat transfer and temperature field information for a vertical GSHP system.

Three-Dimensional Reflectance Traction Microscopy

PubMed Central

Jones, Christopher A. R.; Groves, Nicholas Scott; Sun, Bo

2016-01-01

Cells in three-dimensional (3D) environments exhibit very different biochemical and biophysical phenotypes compared to the behavior of cells in two-dimensional (2D) environments. As an important biomechanical measurement, 2D traction force microscopy can not be directly extended into 3D cases. In order to quantitatively characterize the contraction field, we have developed 3D reflectance traction microscopy which combines confocal reflection imaging and partial volume correlation postprocessing. We have measured the deformation field of collagen gel under controlled mechanical stress. We have also characterized the deformation field generated by invasive breast cancer cells of different morphologies in 3D collagen matrix. In contrast to employ dispersed tracing particles or fluorescently-tagged matrix proteins, our methods provide a label-free, computationally effective strategy to study the cell mechanics in native 3D extracellular matrix. PMID:27304456

Engineering three-dimensional cell mechanical microenvironment with hydrogels.

PubMed

Huang, Guoyou; Wang, Lin; Wang, Shuqi; Han, Yulong; Wu, Jinhui; Zhang, Qiancheng; Xu, Feng; Lu, Tian Jian

2012-12-01

Cell mechanical microenvironment (CMM) significantly affects cell behaviors such as spreading, migration, proliferation and differentiation. However, most studies on cell response to mechanical stimulation are based on two-dimensional (2D) planar substrates, which cannot mimic native three-dimensional (3D) CMM. Accumulating evidence has shown that there is a significant difference in cell behavior in 2D and 3D microenvironments. Among the materials used for engineering 3D CMM, hydrogels have gained increasing attention due to their tunable properties (e.g. chemical and mechanical properties). In this paper, we provide an overview of recent advances in engineering hydrogel-based 3D CMM. Effects of mechanical cues (e.g. hydrogel stiffness and externally induced stress/strain in hydrogels) on cell behaviors are described. A variety of approaches to load mechanical stimuli in 3D hydrogel-based constructs are also discussed.

Three-dimensional modeling and animation of two carpal bones: a technique.

PubMed

Green, Jason K; Werner, Frederick W; Wang, Haoyu; Weiner, Marsha M; Sacks, Jonathan M; Short, Walter H

2004-05-01

The objectives of this study were to (a). create 3D reconstructions of two carpal bones from single CT data sets and animate these bones with experimental in vitro motion data collected during dynamic loading of the wrist joint, (b). develop a technique to calculate the minimum interbone distance between the two carpal bones, and (c). validate the interbone distance calculation process. This method utilized commercial software to create the animations and an in-house program to interface with three-dimensional CAD software to calculate the minimum distance between the irregular geometries of the bones. This interbone minimum distance provides quantitative information regarding the motion of the bones studied and may help to understand and quantify the effects of ligamentous injury.

Numerical modelling techniques of soft soil improvement via stone columns: A brief review

NASA Astrophysics Data System (ADS)

Zukri, Azhani; Nazir, Ramli

2018-04-01

There are a number of numerical studies on stone column systems in the literature. Most of the studies found were involved with two-dimensional analysis of the stone column behaviour, while only a few studies used three-dimensional analysis. The most popular software utilised in those studies was Plaxis 2D and 3D. Other types of software that used for numerical analysis are DIANA, EXAMINE, ZSoil, ABAQUS, ANSYS, NISA, GEOSTUDIO, CRISP, TOCHNOG, CESAR, GEOFEM (2D & 3D), FLAC, and FLAC 3. This paper will review the methodological approaches to model stone column numerically, both in two-dimensional and three-dimensional analyses. The numerical techniques and suitable constitutive model used in the studies will also be discussed. In addition, the validation methods conducted were to verify the numerical analysis conducted will be presented. This review paper also serves as a guide for junior engineers through the applicable procedures and considerations when constructing and running a two or three-dimensional numerical analysis while also citing numerous relevant references.

Toward laboratory torsional spine magnetic reconnection

NASA Astrophysics Data System (ADS)

Chesny, David L.; Orange, N. Brice; Oluseyi, Hakeem M.; Valletta, David R.

2017-12-01

Magnetic reconnection is a fundamental energy conversion mechanism in nature. Major attempts to study this process in controlled settings on Earth have largely been limited to reproducing approximately two-dimensional (2-D) reconnection dynamics. Other experiments describing reconnection near three-dimensional null points are non-driven, and do not induce any of the 3-D modes of spine fan, torsional fan or torsional spine reconnection. In order to study these important 3-D modes observed in astrophysical plasmas (e.g. the solar atmosphere), laboratory set-ups must be designed to induce driven reconnection about an isolated magnetic null point. As such, we consider the limited range of fundamental resistive magnetohydrodynamic (MHD) and kinetic parameters of dynamic laboratory plasmas that are necessary to induce the torsional spine reconnection (TSR) mode characterized by a driven rotational slippage of field lines - a feature that has yet to be achieved in operational laboratory magnetic reconnection experiments. Leveraging existing reconnection models, we show that within a 3$ apparatus, TSR can be achieved in dense plasma regimes ( 24~\\text{m}-3$ ) in magnetic fields of -1~\\text{T}$ . We find that MHD and kinetic parameters predict reconnection in thin current sheets on time scales of . While these plasma regimes may not explicitly replicate the plasma parameters of observed astrophysical phenomena, studying the dynamics of the TSR mode within achievable set-ups signifies an important step in understanding the fundamentals of driven 3-D magnetic reconnection and the self-organization of current sheets. Explicit control of this reconnection mode may have implications for understanding particle acceleration in astrophysical environments, and may even have practical applications to fields such as spacecraft propulsion.

Transonic Investigation of Two-Dimensional Nozzles Designed for Supersonic Cruise

NASA Technical Reports Server (NTRS)

Capone, Francis J.; Deere, Karen A.

2015-01-01

An experimental and computational investigation has been conducted to determine the off-design uninstalled drag characteristics of a two-dimensional convergent-divergent nozzle designed for a supersonic cruise civil transport. The overall objectives were to: (1) determine the effects of nozzle external flap curvature and sidewall boattail variations on boattail drag; (2) develop an experimental data base for 2D nozzles with long divergent flaps and small boattail angles and (3) provide data for correlating computational fluid dynamic predictions of nozzle boattail drag. The experimental investigation was conducted in the Langley 16-Foot Transonic Tunnel at Mach numbers from 0.80 to 1.20 at nozzle pressure ratios up to 9. Three-dimensional simulations of nozzle performance were obtained with the computational fluid dynamics code PAB3D using turbulence closure and nonlinear Reynolds stress modeling. The results of this investigation indicate that excellent correlation between experimental and predicted results was obtained for the nozzle with a moderate amount of boattail curvature. The nozzle with an external flap having a sharp shoulder (no curvature) had the lowest nozzle pressure drag. At a Mach number of 1.2, sidewall pressure drag doubled as sidewall boattail angle was increased from 4deg to 8deg. Reducing the height of the sidewall caused large decreases in both the sidewall and flap pressure drags. Summary

XD-GRASP: Golden-angle radial MRI with reconstruction of extra motion-state dimensions using compressed sensing.

PubMed

Feng, Li; Axel, Leon; Chandarana, Hersh; Block, Kai Tobias; Sodickson, Daniel K; Otazo, Ricardo

2016-02-01

To develop a novel framework for free-breathing MRI called XD-GRASP, which sorts dynamic data into extra motion-state dimensions using the self-navigation properties of radial imaging and reconstructs the multidimensional dataset using compressed sensing. Radial k-space data are continuously acquired using the golden-angle sampling scheme and sorted into multiple motion-states based on respiratory and/or cardiac motion signals derived directly from the data. The resulting undersampled multidimensional dataset is reconstructed using a compressed sensing approach that exploits sparsity along the new dynamic dimensions. The performance of XD-GRASP is demonstrated for free-breathing three-dimensional (3D) abdominal imaging, two-dimensional (2D) cardiac cine imaging and 3D dynamic contrast-enhanced (DCE) MRI of the liver, comparing against reconstructions without motion sorting in both healthy volunteers and patients. XD-GRASP separates respiratory motion from cardiac motion in cardiac imaging, and respiratory motion from contrast enhancement in liver DCE-MRI, which improves image quality and reduces motion-blurring artifacts. XD-GRASP represents a new use of sparsity for motion compensation and a novel way to handle motions in the context of a continuous acquisition paradigm. Instead of removing or correcting motion, extra motion-state dimensions are reconstructed, which improves image quality and also offers new physiological information of potential clinical value. © 2015 Wiley Periodicals, Inc.

XD-GRASP: Golden-Angle Radial MRI with Reconstruction of Extra Motion-State Dimensions Using Compressed Sensing

PubMed Central

Feng, Li; Axel, Leon; Chandarana, Hersh; Block, Kai Tobias; Sodickson, Daniel K.; Otazo, Ricardo

2015-01-01

Purpose To develop a novel framework for free-breathing MRI called XD-GRASP, which sorts dynamic data into extra motion-state dimensions using the self-navigation properties of radial imaging and reconstructs the multidimensional dataset using compressed sensing. Methods Radial k-space data are continuously acquired using the golden-angle sampling scheme and sorted into multiple motion-states based on respiratory and/or cardiac motion signals derived directly from the data. The resulting under-sampled multidimensional dataset is reconstructed using a compressed sensing approach that exploits sparsity along the new dynamic dimensions. The performance of XD-GRASP is demonstrated for free-breathing three-dimensional (3D) abdominal imaging, two-dimensional (2D) cardiac cine imaging and 3D dynamic contrast-enhanced (DCE) MRI of the liver, comparing against reconstructions without motion sorting in both healthy volunteers and patients. Results XD-GRASP separates respiratory motion from cardiac motion in cardiac imaging, and respiratory motion from contrast enhancement in liver DCE-MRI, which improves image quality and reduces motion-blurring artifacts. Conclusion XD-GRASP represents a new use of sparsity for motion compensation and a novel way to handle motions in the context of a continuous acquisition paradigm. Instead of removing or correcting motion, extra motion-state dimensions are reconstructed, which improves image quality and also offers new physiological information of potential clinical value. PMID:25809847

Active vs. spectator modes in nonadiabatic photodissociation dynamics of the hydroxymethyl radical via the 22A(3s) Rydberg state

NASA Astrophysics Data System (ADS)

Xie, Changjian; Guo, Hua

2018-01-01

The choice of the active degrees of freedom (DOFs) is a pivotal issue in a reduced-dimensional model of quantum dynamics when a full-dimensional one is not feasible. Here, several five-dimensional (5D) models are used to investigate the nonadiabatic photodissociation dynamics of the hydroxymethyl (CH2OH) radical, which possesses nine internal DOFs, in its lowest absorption band. A normal-mode based scheme is used to identify the active and spectator modes, and its predictions are confirmed by 5D quantum dynamical calculations. Our results underscore the important role of the CO stretching mode in the photodissociation dynamics of CH2OH, originating from the photo-induced promotion of an electron from the half-occupied π*CO antibonding orbital to a carbon Rydberg orbital.

3D geospatial visualizations: Animation and motion effects on spatial objects

NASA Astrophysics Data System (ADS)

Evangelidis, Konstantinos; Papadopoulos, Theofilos; Papatheodorou, Konstantinos; Mastorokostas, Paris; Hilas, Constantinos

2018-02-01

Digital Elevation Models (DEMs), in combination with high quality raster graphics provide realistic three-dimensional (3D) representations of the globe (virtual globe) and amazing navigation experience over the terrain through earth browsers. In addition, the adoption of interoperable geospatial mark-up languages (e.g. KML) and open programming libraries (Javascript) makes it also possible to create 3D spatial objects and convey on them the sensation of any type of texture by utilizing open 3D representation models (e.g. Collada). One step beyond, by employing WebGL frameworks (e.g. Cesium.js, three.js) animation and motion effects are attributed on 3D models. However, major GIS-based functionalities in combination with all the above mentioned visualization capabilities such as for example animation effects on selected areas of the terrain texture (e.g. sea waves) as well as motion effects on 3D objects moving in dynamically defined georeferenced terrain paths (e.g. the motion of an animal over a hill, or of a big fish in an ocean etc.) are not widely supported at least by open geospatial applications or development frameworks. Towards this we developed and made available to the research community, an open geospatial software application prototype that provides high level capabilities for dynamically creating user defined virtual geospatial worlds populated by selected animated and moving 3D models on user specified locations, paths and areas. At the same time, the generated code may enhance existing open visualization frameworks and programming libraries dealing with 3D simulations, with the geospatial aspect of a virtual world.

3D reconstruction techniques made easy: know-how and pictures.

PubMed

Luccichenti, Giacomo; Cademartiri, Filippo; Pezzella, Francesca Romana; Runza, Giuseppe; Belgrano, Manuel; Midiri, Massimo; Sabatini, Umberto; Bastianello, Stefano; Krestin, Gabriel P

2005-10-01

Three-dimensional reconstructions represent a visual-based tool for illustrating the basis of three-dimensional post-processing such as interpolation, ray-casting, segmentation, percentage classification, gradient calculation, shading and illumination. The knowledge of the optimal scanning and reconstruction parameters facilitates the use of three-dimensional reconstruction techniques in clinical practise. The aim of this article is to explain the principles of multidimensional image processing in a pictorial way and the advantages and limitations of the different possibilities of 3D visualisation.

Three-dimensional imaging of the craniofacial complex.

PubMed

Nguyen, Can X.; Nissanov, Jonathan; Öztürk, Cengizhan; Nuveen, Michiel J.; Tuncay, Orhan C.

2000-02-01

Orthodontic treatment requires the rearrangement of craniofacial complex elements in three planes of space, but oddly the diagnosis is done with two-dimensional images. Here we report on a three-dimensional (3D) imaging system that employs the stereoimaging method of structured light to capture the facial image. The images can be subsequently integrated with 3D cephalometric tracings derived from lateral and PA films (www.clinorthodres.com/cor-c-070). The accuracy of the reconstruction obtained with this inexpensive system is about 400 µ.