WorldWideScience

Sample records for three-dimensional multi-mesh material

  1. MATERIALS COMPATIBILITY STUDY FOR THREE-DIMENSIONAL PRINTER MATERIALS

    Science.gov (United States)

    2017-09-01

    MATERIALS COMPATIBILITY STUDY FOR THREE-DIMENSIONAL PRINTER MATERIALS ECBC-TR-1459 James D. Wright Jr. Mary...REPORT DATE (DD-MM-YYYY) XX-09-2017 2. REPORT TYPE Final 3. DATES COVERED (From - To) Mar 2016 – Dec 2016 4. TITLE AND SUBTITLE Materials ...Compatibility Study for Three-Dimensional Printer Materials 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Wright

  2. Isotropic three-dimensional left-handed meta-materials

    OpenAIRE

    Koschny, Th.; Zhang, L.; Soukoulis, C. M.

    2005-01-01

    We investigate three-dimensional left-handed and related meta-materials based on a fully symmetric multi-gap single-ring SRR design and crossing continuous wires. We demonstrate isotropic transmission properties of a SRR-only meta-material and the corresponding left-handed material which possesses a negative effective index of refraction due to simultaneously negative effective permeability and permittivity. Minor deviations from complete isotropy are due to the finite thickness of the meta-m...

  3. Three-dimensional simulations of void collapse in energetic materials

    Science.gov (United States)

    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.

  4. Three-dimensional magnetic properties of soft magnetic composite materials

    International Nuclear Information System (INIS)

    Lin, Z.W.; Zhu, J.G.

    2007-01-01

    A three-dimensional (3-D) magnetic property measurement system, which can control the three components of the magnetic flux density B vector and measure the magnetic field strength H vector in a cubic sample of soft magnetic material, has been developed and calibrated. This paper studies the relationship between the B and H loci in 3-D space, and the power losses features of a soft magnetic composite when the B loci are controlled to be circles with increasing magnitudes and ellipses evolving from a straight line to circle in three orthogonal planes. It is found that the B and H loci lie in the same magnetization plane, but the H loci and power losses strongly depend on the orientation, position, and process of magnetization. On the other hand, the H vector evolves into a unique locus, and the power loss approaches a unique value, respectively, when the B vector evolves into the round locus with the same magnitude from either a series of circles or ellipses

  5. Advanced three dimensional characterization of silica-based ultraporous materials

    OpenAIRE

    Foray , Genevieve; Roiban , L.; Rong , Q.; Perret , A.; Ihiawakrim , D.; Masenelli-Varlot , K.; Maire , E.; Yrieix , B.

    2016-01-01

    International audience; Whatever the field of application (building, transportation, packaging, etc.) energy losses must be reduced to meet the government target of a 40% cut in CO 2 emissions. This leads to a challenge for materials scientists: designing materials with thermal conductivities lower than 0.015 W m À1 K À1 under ambient conditions. Such a low value requires reducing air molecule mobility in highly porous materials, and silica-based superinsulation materials (SIM) made of packed...

  6. BioProgrammable One, Two, and Three Dimensional Materials

    Science.gov (United States)

    2017-01-18

    with electron beam lithography to simultaneously control material structure at the nano- and macroscopic length scales. The Nguyen group has...probe the structure of the nanoparticle core, oligonucleotide shell, counterion- cloud and inter-PAE electrolyte-mediated interactions. DISTRIBUTION...hydrophobic small molecules (for which multiple syntheses have already been established), and coating them in an amphiphilic polymer containing

  7. Three-dimensional multifunctional hierarchical nanocomposites: multifunctional materials

    Science.gov (United States)

    Ghasemi-Nejhad, Mehrdad N.; Cao, Anyuan

    2007-04-01

    Traditional 1-D and 2-D composite materials have excellent in-plane properties. However, they are susceptible to interlaminar crack and crack growth leading to delaminations and catastrophic failure of the composite structures. To remedy these problems, researchers have developed 3-D composites using through-the-thickness stitching and/or braiding. However, these two techniques have their own problems. For braiding, the part thickness should be known a priori, which is not practical. Besides the fiber architecture is not arranged orthogonally. For the stitching, it has been shown that while through-the-thickness properties increase, in-plane properties decrease. Here, we explain a novel technique, developed by the authors and co-workers, to develop 3-D multifunctional hierarchical nanocomposites with superior properties. In this approach, multi-walled carbon nanotubes (MWCNTs) are grown vertically over 2-D microfiber woven fabric cloth, without altering the 2-D cloth architecture, to create nano-forests coating of MWCNTs in the thickness direction to yield 3-D orthogonal fiber architechture. The 3-D nano-forest woven cloths are later impregnated with the resins and are subsequently stacked, vacuum bagged, and cured to give 3-D multifunctional hierarchical nanocomposites. Since MWCNTs have superior mechanical, thermal, and electrical properties, the hierarchically developed 3-D multifunctional nanocomposites have enhanced mechanical, thermal, thermomechanical, damping, and electrical properties by many folds.

  8. Three-dimensional printing and nanotechnology for enhanced implantable materials

    Science.gov (United States)

    Tappa, Karthik Kumar

    Orthopedic and oro-maxillofacial implants have revolutionized treatment of bone diseases and fractures. Currently available metallic implants have been in clinical use for more than 40 years and have proved medically efficacious. However, several drawbacks remain, such as excessive stiffness, accumulation of metal ions in surrounding tissue, growth restriction, required removal/revision surgery, inability to carry drugs, and susceptibility to infection. The need for additional revision surgery increases financial costs and prolongs recovery time for patients. These metallic implants are bulk manufactured and often do not meet patient's requirements. A surgeon must machine (cut, weld, trim or drill holes) them in order to best suit the patient specifications. Over the past few decades, attempts have been made to replace these metallic implants with suitable biodegradable materials to prevent secondary/revision surgery. Recent advances in biomaterials have shown multiple uses for lactic acid polymers in bone implant technology. However, a targeted/localized drug delivery system needs to be incorporated in these polymers, and they need to be customized to treat orthopedic implant-related infections and other bone diseases such as osteomyelitis, osteosarcoma and osteoporosis. Rapid Prototyping (RP) using additive manufacturing (AM) or 3D printing could allow customization of constructs for personalized medicine. The goal of this study was to engineer customizable and biodegradable implant materials that can elute bioactive compounds for personalized medicine and targeted drug delivery. Post-operative infections are the most common complications following dental, orthopedic and bone implant surgeries. Preventing post-surgical infections is therefore a critical need that current polymethylmethacrylate (PMMA) bone cements fail to address. Calcium Phosphate Cements (CPCs) are unique in their ability to crystallize calcium and phosphate salts into hydroxyapatite (HA) and

  9. An `H'-shape three-dimensional meta-material used in honeycomb structure absorbing material

    Science.gov (United States)

    Huang, Daqing; Kang, Feiyu; Zhou, Zhuohui; Cheng, Hongfei; Ding, Heyan

    2015-03-01

    An `H'-shape three-dimensional meta-material structure which loaded on the sidewall of honeycomb structure absorbing material was designed and fabricated in this project. The simulation results demonstrated a super-wide absorption band below -10 dB between 2.3 and 18 GHz, which expanded 7 GHz compared with the absorber without meta-material. The relative impedance curve was analyzed, which showed that the meta-material has little impact on the impedance-matching characteristics of the honeycomb structure absorbing material. We further studied the distribution of both electronic field energy and magnetic field energy. The former one indicated that the low-frequency absorption peaks could easily be moved by adjusting the parameters of the parallel-plate capacitors which generate electric resonance, and the latter one illustrated that the three-dimensional meta-material could generate magnetic resonance between units which would not exist in two-dimensional meta-material. Then we verified the simulation results through experiment which display a similar absorbing curve. The differences between simulation results and experiment results were caused by the addition substrate of the meta-material, which could not be eliminated in this experiment. However, it still implied that we can obtain a meta-material absorber that has a super-wide absorbing band if we can put the meta-material on the sidewall of the honeycomb without attachments.

  10. Three-diemensional materials science: An intersection of three-dimensional reconstructions and simulations

    DEFF Research Database (Denmark)

    Thornton, Katsuyo; Poulsen, Henning Friis

    2008-01-01

    The recent development of experimental techniques that rapidly reconstruct the three-dimensional microstructures of solids has given rise to new possibilities for developing a deeper understanding of the evolution of microstructures and the effects of microstructures on materials properties. Comb...... an overview of this emerging field of materials science, as well as brief descriptions of selected methods and their applicability.......The recent development of experimental techniques that rapidly reconstruct the three-dimensional microstructures of solids has given rise to new possibilities for developing a deeper understanding of the evolution of microstructures and the effects of microstructures on materials properties....... Combined with three-dimensional (3D) simulations and analyses that are capable of handling the complexity of these microstructures, 3D reconstruction, or tomography, has become a powerful tool that provides clear insights into materials processing and properties. This introductory article provides...

  11. Segregation of Granular Material in Two and Three-Dimensional Units

    Indian Academy of Sciences (India)

    Segregation of particulate materials in mixtures is controlledby differences in density, shape, and size. Experiments on segregationwere performed in two and three-dimensional demonstrationunits. The results conclusively indicated that the segregationof solids is affected by the shape, size and density ofgranular particles.

  12. The three-dimensional microstructure of polycrystalline materials unravelled by synchrotron light

    DEFF Research Database (Denmark)

    Ludwig, W.; King, A.; Herbig, M.

    2011-01-01

    (different crystallographic phases, cracks, porosities) can be detected using 3D imaging modes exploiting Fresnel diffraction and the coherence properties of third generation synchrotron beams. X-ray diffraction contrast tomography, a technique based on Bragg diffraction imaging, provides access to the 3D......The three-dimensional microstructure of polycrystalline materials unravelled by synchrotron light Synchrotron radiation X-ray imaging and diffraction techniques offer new possibilities for non-destructive bulk characterization of polycrystalline materials. Minute changes in electron density...

  13. Capillary pressure and liquid wicking in three-dimensional nonwoven materials

    Science.gov (United States)

    Mao, N.; Russell, S. J.

    2008-08-01

    The capillary pressure and liquid wicking in fibrous nonwoven materials depend on the structural arrangement of fibers in three dimensions, which is influenced by the method and conditions used to manufacture the material. By adapting the hydraulic radius mechanism and drag force theory, a model is established for predicting the directional capillary pressure in three-dimensional nonwoven materials. As a case study, equations to predict the velocity of liquid wicking in a one-dimensional wicking strip test for nonwovens having a three-dimensional fiber orientation distribution are given based on the newly established capillary pressure model. These models and equations are based on measurable structural parameters including the fiber orientation distribution, fiber diameter, and fabric porosity.

  14. Cyrogenic and radiation resistant properties of three dimensional fabric reinforced composite materials

    International Nuclear Information System (INIS)

    Yasuda, J.; Hirodawa, T.; Uemura, T.; Iwasaki, Y.; Nishijima, S.; Okada, T.; Okuyama, H.; Wang, Y.A.

    1988-01-01

    The insulating and/or structural materials for the fusion superconducting magnets are used under such strict environments as the cryogenic temperatures, high stresses and radiation environments. It is recognized that the usual laminated composite materials reinforced by glass clothes (2D-GFRP) are difficult to be used in such strict conditions. The three dimensional glass fabric reinforced composite materials (3D-GFRP) have high interlaminar shear strength due to the fibers in thickness direction. The cryogenic and radiation resistance properties of 3D-GFRP had been measured and the results compared with those of the 2D-GFRP

  15. A three-dimensional model for T-shaped acoustic resonators with sound absorption materials.

    Science.gov (United States)

    Yu, Ganghua; Cheng, Li; Li, Deyu

    2011-05-01

    Recent development in noise control using T-shaped acoustic resonators calls for the development of more reliable and accurate models to predict their acoustic characteristics, which is unfortunately lacking in the literature. This paper attempts to establish such a model based on three-dimensional theory for T-shaped acoustic resonators containing sound absorption materials. The model is validated by experiments using various configurations. Predictions on fundamental and high-order resonance frequencies are compared with those obtained from the one-dimensional model and finite element analyses, and the effects of the physical and geometric parameters of the absorption materials on the resonance frequencies and Q-factor are also investigated numerically and experimentally. Limitations and applicability of existing one-dimensional models are assessed. The proposed general three-dimensional model proved to be able to provide an accurate and reliable prediction on the resonance frequencies for T-shaped acoustic resonators with or without absorption materials. This can eventually meet the requirement for resonator array design in terms of accuracy.

  16. The three-dimensional microstructure of polycrystalline materials unravelled by synchrotron light

    DEFF Research Database (Denmark)

    Ludwig, W.; King, A.; Herbig, M.

    2011-01-01

    (different crystallographic phases, cracks, porosities) can be detected using 3D imaging modes exploiting Fresnel diffraction and the coherence properties of third generation synchrotron beams. X-ray diffraction contrast tomography, a technique based on Bragg diffraction imaging, provides access to the 3D......The three-dimensional microstructure of polycrystalline materials unravelled by synchrotron light Synchrotron radiation X-ray imaging and diffraction techniques offer new possibilities for non-destructive bulk characterization of polycrystalline materials. Minute changes in electron density...... shape, orientation and elastic strain state of the individual grains from polycrystalline sample volumes containing several hundred up to a few thousand grains. Combining both imaging modalities allows a comprehensive description of the microstructure of the material at the micrometer length scale...

  17. Three-dimensional organic Dirac-line materials due to nonsymmorphic symmetry: A data mining approach

    Science.gov (United States)

    Geilhufe, R. Matthias; Bouhon, Adrien; Borysov, Stanislav S.; Balatsky, Alexander V.

    2017-01-01

    A data mining study of electronic Kohn-Sham band structures was performed to identify Dirac materials within the Organic Materials Database. Out of that, the three-dimensional organic crystal 5,6-bis(trifluoromethyl)-2-methoxy-1 H -1,3-diazepine was found to host different Dirac-line nodes within the band structure. From a group theoretical analysis, it is possible to distinguish between Dirac-line nodes occurring due to twofold degenerate energy levels protected by the monoclinic crystalline symmetry and twofold degenerate accidental crossings protected by the topology of the electronic band structure. The obtained results can be generalized to all materials having the space group P 21/c (No. 14, C2h 5) by introducing three distinct topological classes.

  18. Three-dimensional Mesoscale Simulations of Detonation Initiation in Energetic Materials with Density-based Kinetics

    Science.gov (United States)

    Jackson, Thomas; Jost, A. M.; Zhang, Ju; Sridharan, P.; Amadio, G.

    2017-06-01

    In this work we present three-dimensional mesoscale simulations of detonation initiation in energetic materials. We solve the reactive Euler equations, with the energy equation augmented by a power deposition term. The reaction rate at the mesoscale is modelled using a density-based kinetics scheme, adapted from standard Ignition and Growth models. The deposition term is based on previous results of simulations of pore collapse at the microscale, modelled at the mesoscale as hot-spots. We carry out three-dimensional mesoscale simulations of random packs of HMX crystals in a binder, and show that the transition between no-detonation and detonation depends on the number density of the hot-spots, the initial radius of the hot-spot, the post-shock pressure of an imposed shock, and the amplitude of the power deposition term. The trends of transition at lower pressure of the imposed shock for larger number density of pore observed in experiments is reproduced. Initial attempts to improve the agreement between the simulation and experiments through calibration of various parameters will also be made.

  19. Three-dimensional vibration analysis of functionally graded material plates in thermal environment

    Science.gov (United States)

    Li, Q.; Iu, V. P.; Kou, K. P.

    2009-07-01

    Free vibration of functionally graded material rectangular plates with simply supported and clamped edges in the thermal environment is studied based on the three-dimensional linear theory of elasticity. Simply supported and clamped FGM plates with temperature-dependent material properties subjected to uniform temperature rise, linear temperature rise and nonlinear temperature rise are considered. The three displacements of the plates are expanded by a series of Chebyshev polynomials multiplied by appropriate functions to satisfy the essential boundary conditions. The natural frequencies are obtained by Ritz method. The numerical results of the present approach are compared with the results of other researchers for the validation. Parametric study is performed for supported conditions, temperature fields, volume fraction indices of FGM plates.

  20. Three-dimensional vibration analysis of functionally graded material sandwich plates

    Science.gov (United States)

    Li, Q.; Iu, V. P.; Kou, K. P.

    2008-03-01

    Free vibration of functionally graded material sandwich rectangular plates with simply supported and clamped edges is studied based on the three-dimensional linear theory of elasticity. Two common types of FGM sandwich plates, namely, the sandwich with FGM facesheet and homogeneous core and the sandwich with homogeneous facesheet and FGM core, are considered. The three displacements of the plates are expanded by a series of Chebyshev polynomials multiplied by appropriate functions to satisfy the essential boundary conditions. The natural frequencies are obtained by Ritz method. Rapid convergence is observed in this study. The natural frequencies of simply supported power-law FGM sandwich plates are compared with results from different two-dimensional plate theories. Parametric study is performed for varying volume fraction, layer thickness ratios, thickness-length ratios and aspect ratios of the sandwich plates.

  1. A novel three-dimensional scaffold for regenerative endodontics: materials and biological characterizations.

    Science.gov (United States)

    Bottino, Marco C; Yassen, Ghaeth H; Platt, Jeffrey A; Labban, Nawaf; Windsor, L Jack; Spolnik, Kenneth J; Bressiani, Ana H A

    2015-11-01

    An electrospun nanocomposite fibrous material holds promise as a scaffold, as well as a drug-delivery device to aid in root maturogenesis and the regeneration of the pulp-dentine complex. A novel three-dimensional (3D) nanocomposite scaffold composed of polydioxanone (PDS II®) and halloysite nanotubes (HNTs) was designed and fabricated by electrospinning. Morphology, structure, mechanical properties and cell compatibility studies were carried out to evaluate the effects of HNTs incorporation (0.5-10 wt% relative to PDS w/w). Overall, a 3D porous network was seen in the different fabricated electrospun scaffolds, regardless of the HNT content. The incorporation of HNTs at 10 wt% led to a significant (p endodontics. Copyright © 2013 John Wiley & Sons, Ltd.

  2. Three-dimensional Architecture Enabled by Strained Two-dimensional Material Heterojunction.

    Science.gov (United States)

    Lou, Shuai; Liu, Yin; Yang, Fuyi; Lin, Shuren; Zhang, Ruopeng; Deng, Yang; Wang, Michael; Tom, Kyle B; Zhou, Fei; Ding, Hong; Bustillo, Karen C; Wang, Xi; Yan, Shancheng; Scott, Mary; Minor, Andrew; Yao, Jie

    2018-03-14

    Engineering the structure of materials endows them with novel physical properties across a wide range of length scales. With high in-plane stiffness and strength, but low flexural rigidity, two-dimensional (2D) materials are excellent building blocks for nanostructure engineering. They can be easily bent and folded to build three-dimensional (3D) architectures. Taking advantage of the large lattice mismatch between the constituents, we demonstrate a 3D heterogeneous architecture combining a basal Bi 2 Se 3 nanoplate and wavelike Bi 2 Te 3 edges buckling up and down forming periodic ripples. Unlike 2D heterostructures directly grown on substrates, the solution-based synthesis allows the heterostructures to be free from substrate influence during the formation process. The balance between bending and in-plane strain energies gives rise to controllable rippling of the material. Our experimental results show clear evidence that the wavelengths and amplitudes of the ripples are dependent on both the widths and thicknesses of the rippled material, matching well with continuum mechanics analysis. The rippled Bi 2 Se 3 /Bi 2 Te 3 heterojunction broadens the horizon for the application of 2D materials heterojunction and the design and fabrication of 3D architectures based on them, which could provide a platform to enable nanoscale structure generation and associated photonic/electronic properties manipulation for optoelectronic and electromechanic applications.

  3. Three-Dimensional (3D Printing of Polymer-Metal Hybrid Materials by Fused Deposition Modeling

    Directory of Open Access Journals (Sweden)

    Susanna Fafenrot

    2017-10-01

    Full Text Available Fused deposition modeling (FDM is a three-dimensional (3D printing technology that is usually performed with polymers that are molten in a printer nozzle and placed line by line on the printing bed or the previous layer, respectively. Nowadays, hybrid materials combining polymers with functional materials are also commercially available. Especially combinations of polymers with metal particles result in printed objects with interesting optical and mechanical properties. The mechanical properties of objects printed with two of these metal-polymer blends were compared to common poly (lactide acid (PLA printed objects. Tensile tests and bending tests show that hybrid materials mostly containing bronze have significantly reduced mechanical properties. Tensile strengths of the 3D-printed objects were unexpectedly nearly identical with those of the original filaments, indicating sufficient quality of the printing process. Our investigations show that while FDM printing allows for producing objects with mechanical properties similar to the original materials, metal-polymer blends cannot be used for the rapid manufacturing of objects necessitating mechanical strength.

  4. Three-Dimensional (3D) Printing of Polymer-Metal Hybrid Materials by Fused Deposition Modeling.

    Science.gov (United States)

    Fafenrot, Susanna; Grimmelsmann, Nils; Wortmann, Martin; Ehrmann, Andrea

    2017-10-19

    Fused deposition modeling (FDM) is a three-dimensional (3D) printing technology that is usually performed with polymers that are molten in a printer nozzle and placed line by line on the printing bed or the previous layer, respectively. Nowadays, hybrid materials combining polymers with functional materials are also commercially available. Especially combinations of polymers with metal particles result in printed objects with interesting optical and mechanical properties. The mechanical properties of objects printed with two of these metal-polymer blends were compared to common poly (lactide acid) (PLA) printed objects. Tensile tests and bending tests show that hybrid materials mostly containing bronze have significantly reduced mechanical properties. Tensile strengths of the 3D-printed objects were unexpectedly nearly identical with those of the original filaments, indicating sufficient quality of the printing process. Our investigations show that while FDM printing allows for producing objects with mechanical properties similar to the original materials, metal-polymer blends cannot be used for the rapid manufacturing of objects necessitating mechanical strength.

  5. Evaluation of Three-Dimensional Printed Materials for Simulation by Computed Tomography and Ultrasound Imaging.

    Science.gov (United States)

    Mooney, James J; Sarwani, Nabeel; Coleman, Melissa L; Fotos, Joseph S

    2017-06-01

    The use of three-dimensional (3D) printing allows for creation of custom models for clinical care, education, and simulation. Medical imaging, given the significant role it plays in both clinical diagnostics and procedures, remains an important area for such education and simulation. Unfortunately, the materials appropriate for use in simulation involving radiographic or ultrasound imaging remains poorly understood. Therefore, our study was intended to explore the characteristics of readily available 3D printing materials when visualized by computed tomography (CT) and ultrasound. Seven 3D printing materials were examined in standard shapes (cube, cylinder, triangular prism) with a selection of printing methods ("open," "whole," and "solid" forms). For CT imaging, these objects were suspended in a gelatin matrix molded to match a standard human CT phantom. For ultrasound imaging, the objects were placed in acrylic forms filled with a gelatin matrix. All images were examined using OsiriX software. Computed tomography imaging revealed marked variation in materials' Hounsfield units as well as patterning and artifact. The Hounsfield unit variations revealed a number of materials suitable for simulation various human tissues. Ultrasound imaging showed echogenicity in all materials, with some variability in shadowing and posterior wall visualization. We were able to demonstrate the potential utility for 3D printing in the creation of CT and ultrasound simulation models. The similar appearance of materials via ultrasound supports their broad utility for select tissue types, whereas the more variable appearance via CT suggests greater potential for simulating differing tissues but requiring multiple printer technologies to do so.

  6. Dynamics of pre-strained bi-material elastic systems linearized three-dimensional approach

    CERN Document Server

    Akbarov, Surkay D

    2015-01-01

    This book deals with dynamics of pre-stressed or pre-strained bi-material elastic systems consisting of stack of pre-stressed layers, stack of pre-stressed layers and pre-stressed half space (or half plane), stack of pre-stressed layers as well as absolute rigid foundation, pre-stressed compound solid and hollow cylinders and pre-stressed sandwich hollow cylinders. The problems considered in the book relate to the dynamics of a moving and oscillating moving load, forced vibration caused by linearly located or point located time-harmonic forces acting to the foregoing systems. Moreover, a considerable part of the book relate to the problems regarding the near surface, torsional and axisymmetric longitudinal waves propagation and dispersion in the noted above bi-material elastic systems. The book carries out the investigations within the framework of the piecewise homogeneous body model with the use of the Three-Dimensional Linearized Theory of Elastic Waves in Initially Stressed Bodies.

  7. A novel three-dimensional auxetic lattice meta-material with enhanced stiffness

    Science.gov (United States)

    Chen, Yu; Fu, Ming-Hui

    2017-10-01

    This paper proposes a three-dimensional (3D) lattice meta-material made by extending the existing two-dimensional enhanced auxetic model to a 3D one. With narrow ribs embedded into every cell of the typical 3D re-entrant honeycomb (TRH), the new structure can also be considered as an enhanced design of the TRH. A combination of theoretical and numerical analysis is carried out to gain a deeper understanding of the elastic behavior of the new 3D structure and its dependence on the geometric parameters. The new structure is proved analytically and numerically to exhibit a negative Poisson’s ratio, while its Young’s modulus is significantly improved compared to that of the TRH. It is remarkable that the Young’s modulus of the new structure increases linearly with the relative density while an approximate square relation is found between that of the THR and the relative density, which reveals that the dominated deformation model of the micro-structures has been changed by the embedded ribs from bending to stretching. The present layout may be promising for some special applications due to its superior performance and may provide a new concept for the optimization design of 3D auxetic materials, whose stiffness is relatively low.

  8. Recent advances in three-dimensional graphene based materials for catalysis applications.

    Science.gov (United States)

    Qiu, Bocheng; Xing, Mingyang; Zhang, Jinlong

    2018-03-21

    Over the past few decades, two-dimensional graphene based materials (2DGMs) have piqued the interest of scientists worldwide, and the exploration of their potential applications in catalysis, sensors, electronic devices and energy storage due to their extraordinary physical and chemical properties has rapidly progressed. As for these 2DGMs, there is a complementary need to assemble 2D building blocks hierarchically into more complicated and hierarchical three-dimensional graphene-based materials (3DGMs). Such a capability is vitally crucial in order to design sophisticated and multi-functional catalysts with tailorable properties. This comprehensive review describes some important recent advances with respect to 3DGMs, including their preparation methods, characterization and applications in catalysis, e.g., photocatalysis, electrocatalysis, organic catalysis, and CO oxidation. The importance of the relationship between the structure and catalytic performance, a topic which has become a central focus of research in order to develop high-performance catalytic systems, is discussed. Likely future developments and their associated challenges are proposed and discussed.

  9. Three-dimensional reconstruction of fracture surfaces of CFRP type composite materials

    International Nuclear Information System (INIS)

    Lobo, Raquel de Moraes

    2009-01-01

    The three-dimensional reconstruction of fracture surfaces of CFRP type composite materials is presented in this work as a possible method for the fractographic analysis of this material, whose rupture surface can present an accentuated roughness, with great variation in height. Two methods are presented for this purpose: the reconstruction for variable focus, carried through with images of optic microscopy and the reconstruction for parallax, carried through with pair of stereo images, obtained by means of scanning electronic microscopy. An evaluation is carried through for each one of the two methods, having argued its limits and the efficiency of each one of them, before the difficulties of analysis of unidirectional and multidirectional composite materials. The method of variable focus presented an excellent reconstruction result, but it has the need of a great number of images, spent time of the instrument and magnifying limit of the images as factors to be considered in the choice of better method. The tilting of the specimen, during the parallax method, discloses alterations in the histograms of the images acquired in the clockwise direction that limit the use of the method for materials with high roughness. The acquiring of images in only one direction and the construction of a region of interest, located in the center of the image are suggestions to turn the method most including. The linearity of the projections of features in the inclined image also suggests the possibility to carry through the reconstruction using, instead of only two, multiple images gotten in the counter-clockwise direction. The alterations proposals to modify the routine, are suggested so that the program can be applied in a more comprehensive form, independent of the quality of the observed fracture surface. (author)

  10. Three-dimensional visualization of material flow during friction stir welding by two pairs of X-ray transmission systems

    International Nuclear Information System (INIS)

    Morisada, Y.; Fujii, H.; Kawahito, Y.; Nakata, K.; Tanaka, M.

    2011-01-01

    Material flow during friction stir welding is crucial to obtaining sound joints. However, this phenomenon is still not fully understood despite many investigations and numerous models. In this study, the material flow is three-dimensionally visualized by X-ray radiography using a tiny spherical tungsten tracer. The movement of the tracer during the friction stir welding is observed by two pairs of X-ray transmission real-time imaging systems. The three-dimensional material flow is obtained by following the locus of the tracer.

  11. Extending the XFEM approach for fast transient three-dimensional crack propagation in ductile materials

    International Nuclear Information System (INIS)

    Pelee-De-Saint-Maurice, Romains

    2014-01-01

    This PhD thesis presents numerical methods is dedicated to three-dimensional crack propagation in the framework of fast explicit structural dynamics using EUROPLEXUS software (currently abbreviated EPX, co-owned by CEA and EC/JRC). An approach based on the well-known XFEM method is proposed, representing the crack through level set functions. Special care is given to the update of the level set functions from the propagation velocity expressed on the crack edge, since the most widely used method based on the solution of Hamilton-Jacobi equations lacks robustness for fast transient crack propagations, even when level-sets are computed on an auxiliary regular finite difference grid. It is therefore chosen instead to implement a 3D approximated geometric method to update both level-sets. As far as failure mechanics is concerned, a local stress criterion on the edge of the crack, first developed by Haboussa et al., gives characteristic parameters of the material fracture. Mechanical equivalent quantities (strain, deformation) around the crack front are weighted by a Gaussian function, which gives more importance to Gauss integration points located near the crack tip. The maximum of the equivalent stress tensor near the crack tip gives the direction of the crack, and the Kanninen equation gives the crack velocity. Besides, because of the discontinuous displacement field, the numerical integration for elements cut by the crack yields performance issues. Increasing the number of quadrature points is CPU time consuming and quite hard to handle if it is chosen to change the number of points only for elements in the vicinity of the crack. Another approach tested here consists in keeping constant the number and position of quadrature points and modifying their weights in cut elements to obtain an accurate integration of several reference discontinuous fields. The proposed methods are tested and validated on significant examples, both two-dimensional, to ensure the backward

  12. Electron Tomography: A Three-Dimensional Analytic Tool for Hard and Soft Materials Research.

    Science.gov (United States)

    Ercius, Peter; Alaidi, Osama; Rames, Matthew J; Ren, Gang

    2015-10-14

    Three-dimensional (3D) structural analysis is essential to understand the relationship between the structure and function of an object. Many analytical techniques, such as X-ray diffraction, neutron spectroscopy, and electron microscopy imaging, are used to provide structural information. Transmission electron microscopy (TEM), one of the most popular analytic tools, has been widely used for structural analysis in both physical and biological sciences for many decades, in which 3D objects are projected into two-dimensional (2D) images. In many cases, 2D-projection images are insufficient to understand the relationship between the 3D structure and the function of nanoscale objects. Electron tomography (ET) is a technique that retrieves 3D structural information from a tilt series of 2D projections, and is gradually becoming a mature technology with sub-nanometer resolution. Distinct methods to overcome sample-based limitations have been separately developed in both physical and biological science, although they share some basic concepts of ET. This review discusses the common basis for 3D characterization, and specifies difficulties and solutions regarding both hard and soft materials research. It is hoped that novel solutions based on current state-of-the-art techniques for advanced applications in hybrid matter systems can be motivated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. A three-dimensional strain measurement method in elastic transparent materials using tomographic particle image velocimetry.

    Directory of Open Access Journals (Sweden)

    Azuma Takahashi

    Full Text Available The mechanical interaction between blood vessels and medical devices can induce strains in these vessels. Measuring and understanding these strains is necessary to identify the causes of vascular complications. This study develops a method to measure the three-dimensional (3D distribution of strain using tomographic particle image velocimetry (Tomo-PIV and compares the measurement accuracy with the gauge strain in tensile tests.The test system for measuring 3D strain distribution consists of two cameras, a laser, a universal testing machine, an acrylic chamber with a glycerol water solution for adjusting the refractive index with the silicone, and dumbbell-shaped specimens mixed with fluorescent tracer particles. 3D images of the particles were reconstructed from 2D images using a multiplicative algebraic reconstruction technique (MART and motion tracking enhancement. Distributions of the 3D displacements were calculated using a digital volume correlation. To evaluate the accuracy of the measurement method in terms of particle density and interrogation voxel size, the gauge strain and one of the two cameras for Tomo-PIV were used as a video-extensometer in the tensile test. The results show that the optimal particle density and interrogation voxel size are 0.014 particles per pixel and 40 × 40 × 40 voxels with a 75% overlap. The maximum measurement error was maintained at less than 2.5% in the 4-mm-wide region of the specimen.We successfully developed a method to experimentally measure 3D strain distribution in an elastic silicone material using Tomo-PIV and fluorescent particles. To the best of our knowledge, this is the first report that applies Tomo-PIV to investigate 3D strain measurements in elastic materials with large deformation and validates the measurement accuracy.

  14. Three dimensional finite element analysis of layered fiber-reinforced composite materials

    Science.gov (United States)

    Lee, J. D.

    1980-01-01

    A three-dimensional finite element analysis was performed for a biaxially loaded composite laminate (with a centered hole) consisting of several fiber-reinforced composite layers each with a specified fiber orientation. The detailed stress distribution around the hole was determined. Also, the locations of initial damage zones due to different failure mechanisms were indicated.

  15. Three-Dimensional Printing of X-Ray Computed Tomography Datasets with Multiple Materials Using Open-Source Data Processing

    Science.gov (United States)

    Sander, Ian M.; McGoldrick, Matthew T.; Helms, My N.; Betts, Aislinn; van Avermaete, Anthony; Owers, Elizabeth; Doney, Evan; Liepert, Taimi; Niebur, Glen; Liepert, Douglas; Leevy, W. Matthew

    2017-01-01

    Advances in three-dimensional (3D) printing allow for digital files to be turned into a "printed" physical product. For example, complex anatomical models derived from clinical or pre-clinical X-ray computed tomography (CT) data of patients or research specimens can be constructed using various printable materials. Although 3D printing…

  16. Three-Dimensionally Isotropic Negative Refractive Index Materials from Block Copolymer Self-Assembled Chiral Gyroid Networks

    KAUST Repository

    Hur, Kahyun

    2011-10-17

    Metamaterials are engineered artificial materials that offer new functionalities such as super-resolution imaging and cloaking. Calculations of the photonic properties of three-dimensionally isotropic metamaterials with cubic double gyroid and alternating gyroid morphologies from block copolymer self-assembly are presented.

  17. Material migration in tokamak plasmas with a three-dimensional boundary

    International Nuclear Information System (INIS)

    Laengner, Ruth

    2013-01-01

    In this work, the influence of a 3D boundary induced by resonant magnetic perturbations (RMPs) on the material migration, i.e. the erosion from wall material due to the plasma surface interaction and the transport of these impurities is investigated for the first time. With applied RMPs two new domains occur in the magnetic field structure. Three dimensional SOL flux tubes with predominantly transport parallel to short magnetic field lines and a region of longer stochastic field lines with diffusive gradient driven radial transport. The plasma wall interaction and the material transport in these domains were investigated. A globally higher radial electric field E r as well as local changes in the magnetic field structure such as pressure driven sonic flows or locally higher E r fields can potentially influence the material transport with applied RMPs. The experiments were performed at the tokamak TEXTOR, the RMPs were induced by the dynamic ergodic divertor (DED). The plasma discharges and DED application was chosen to have a spatially separated 3D structure to be able to investigate the underlying physics. Two spherical carbon test limiters were positioned in different poloidal and toroidal positions which allowed to analyse the material migration in a 3D SOL flux tube and a stochastic region at the same time. Methane doped with 13 C was injected through the test limiters during three different plasma scenarios, without RMPs, with static RMPs and an RMP sweep. The test limiters and the injected methane were monitored in situ with different cameras and spectrometers. The deposition of the injected particles was measured post mortem by colourimetry, nuclear reaction analysis and secondary ion mass spectrometry. The most profound change from no RMP to the RMP cases is a 90 re-direction of the low ionised carbon C + and C 2+ into the E r x B-drift direction. From a comparison of the experiments and numerical field line tracing it was found that this is a global effect

  18. Characteristics of sandwich-type structural elements built of advanced composite materials from three dimensional fabrics

    Directory of Open Access Journals (Sweden)

    Castejón, L.

    1997-12-01

    Full Text Available Sandwich-type structures have proved to be alternatives of great success for several fields of application, and specially in the building sector. This is due to their outstanding properties of .specific rigidity and strength against bending loads and other range of advantages like fatigue and impact resistance, attainment of flat and smooth surfaces, high electric and thermal insulation, design versatility and some others. However, traditional sandwich structures present problems like their tendency towards delamination, stress concentrations in bores or screwed Joints, and pre resistance. These problems are alleviated thanks to the use of new sandwich structures built using three dimensional structures of advanced composite materials, maintaining the present advantages for more traditional sandwich structures. At this rate, these new structures can be applied in several areas where conventional sandwich structures used to be like walls, partitions, floor and ceiling structures, domes, vaults and dwellings, but with greater success.

    Las estructuras tipo sándwich han demostrado ser alternativas de gran éxito para diversos campos de aplicación y, en concreto, en el sector de la construcción, listo es gracias a sus excelentes propiedades de rigidez y resistencia específica frente a cargas de flexión y otra larga lista de ventajas, a la que pertenecen, por ejemplo, su buena resistencia a fatiga, resistencia al impacto, obtención de superficies lisas y suaves, elevado aislamiento térmico y eléctrico, versatilidad de diseño y otras. Sin embargo, las estructuras sándwich, tradicionales presentan una problemática consistente en su tendencia a la delaminación, concentraciones de tensiones ¿aparecidas ante la existencia de agujeros o uniones atornilladas y resistencia al fuego. Estos problemas son pifiados gracias a la aplicación de estructuras novedosas tipo sándwich, construidas a partir de tejidos tridimensionales de materiales

  19. Hypersonic modulation of light in three-dimensional photonic and phononic band-gap materials.

    Science.gov (United States)

    Akimov, A V; Tanaka, Y; Pevtsov, A B; Kaplan, S F; Golubev, V G; Tamura, S; Yakovlev, D R; Bayer, M

    2008-07-18

    The elastic coupling between the a-SiO2 spheres composing opal films brings forth three-dimensional periodic structures which besides a photonic stop band are predicted to also exhibit complete phononic band gaps. The influence of elastic crystal vibrations on the photonic band structure has been studied by injection of coherent hypersonic wave packets generated in a metal transducer by subpicosecond laser pulses. These studies show that light with energies close to the photonic band gap can be efficiently modulated by hypersonic waves.

  20. Real-time terahertz material characterization by numerical three-dimensional optimization.

    Science.gov (United States)

    Scheller, Maik

    2011-05-23

    Terahertz time domain spectroscopy allows for characterization of dielectrics even in cases where the samples thickness is unknown. However, a parameter extraction over a broad frequency range with simultaneous thickness determination is time consuming using conventional algorithms due to the large number of optimization steps. In this paper we present a novel method to extract the data. By employing a three dimensional optimization algorithm the calculation effort is significantly reduced while preserving the same accuracy level as conventional approaches. The presented method is even fast enough to be used in imaging applications.

  1. Observation of three-dimensional internal structure of steel materials by means of serial sectioning with ultrasonic elliptical vibration cutting.

    Science.gov (United States)

    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.

  2. Three-Dimensional Elasticity Solutions for Sound Radiation of Functionally Graded Materials Plates considering State Space Method

    Directory of Open Access Journals (Sweden)

    Tieliang Yang

    2016-01-01

    Full Text Available This paper presents an analytical study for sound radiation of functionally graded materials (FGM plate based on the three-dimensional theory of elasticity. The FGM plate is a mixture of metal and ceramic, and its material properties are assumed to have smooth and continuous variation in the thickness direction according to a power-law distribution in terms of volume fractions of the constituents. Based on the three-dimensional theory of elasticity and state space method, the governing equations with variable coefficients of the FGM plate are derived. The sound radiation of the vibration plate is calculated with Rayleigh integral. Comparisons of the present results with those of solutions in the available literature are made and good agreements are achieved. Finally, some parametric studies are carried out to investigate the sound radiation properties of FGM plates.

  3. Three-dimensional free vibration analysis of functionally graded material plates resting on an elastic foundation

    Science.gov (United States)

    Amini, M. H.; Soleimani, M.; Rastgoo, A.

    2009-08-01

    This paper describes a method for three-dimensional free vibration analysis of rectangular FGM plates resting on an elastic foundation using Chebyshev polynomials and Ritz's method. The thickness can vary from thin to very thick. The elastic foundation is considered as a Winkler model. The analysis is based on a linear, small-strain, three-dimensional elasticity theory. The proposed technique yields very accurate natural frequencies and mode shapes of rectangular plates with arbitrary boundary conditions. A simple and general programme has been used for this purpose. For a plate with geometric symmetry, the vibration modes can be classified into symmetric and antisymmetric ones in that direction. In such a case, the computational cost can be greatly reduced while maintaining the same level of accuracy. Convergence studies and a comparison have been carried out using isotropic and FGM square plates with four simply-supported and clamped edges as examples. The results show that the present method enables rapid convergence, stable numerical operation and very high computational accuracy. Parametric investigations are presented for two-constituent metal-ceramic functionally graded clamped square plates on an elastic foundation with respect to different thickness-side ratios, gradient indexes and foundation stiffnesses.

  4. Three-dimensional free vibration analysis of functionally graded material plates resting on an elastic foundation

    International Nuclear Information System (INIS)

    Amini, M H; Soleimani, M; Rastgoo, A

    2009-01-01

    This paper describes a method for three-dimensional free vibration analysis of rectangular FGM plates resting on an elastic foundation using Chebyshev polynomials and Ritz's method. The thickness can vary from thin to very thick. The elastic foundation is considered as a Winkler model. The analysis is based on a linear, small-strain, three-dimensional elasticity theory. The proposed technique yields very accurate natural frequencies and mode shapes of rectangular plates with arbitrary boundary conditions. A simple and general programme has been used for this purpose. For a plate with geometric symmetry, the vibration modes can be classified into symmetric and antisymmetric ones in that direction. In such a case, the computational cost can be greatly reduced while maintaining the same level of accuracy. Convergence studies and a comparison have been carried out using isotropic and FGM square plates with four simply-supported and clamped edges as examples. The results show that the present method enables rapid convergence, stable numerical operation and very high computational accuracy. Parametric investigations are presented for two-constituent metal–ceramic functionally graded clamped square plates on an elastic foundation with respect to different thickness–side ratios, gradient indexes and foundation stiffnesses

  5. Three-dimensional reticular tin-manganese oxide composite anode materials for lithium ion batteries

    International Nuclear Information System (INIS)

    Zhu, X.J.; Guo, Z.P.; Zhang, P.; Du, G.D.; Poh, C.K.; Chen, Z.X.; Li, S.; Liu, H.K.

    2010-01-01

    Tin-manganese oxide film with three-dimensional (3D) reticular structure has been prepared by electrostatic spray deposition (ESD). X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicate that the film is amorphous. X-ray-photoemission spectroscopy (XPS) demonstrates that the 3D grid is composed of tin-manganese oxide. As an anode electrode for the lithium ion battery, the tin-manganese oxide film has 1188.3 mAh g -1 of initial discharge capacity and very good capacity retention of 656.2 mAh g -1 up to the 30th cycle. Such a composite film can be used as an anode for lithium ion batteries with higher energy densities.

  6. Formulation of stiffness equation for a three-dimensional isoparametric element with elastic-plastic material and large deformation

    International Nuclear Information System (INIS)

    Chang, T.Y.; Prachuktam, S.; Reich, M.

    1975-01-01

    The formulation of the stiffness equation for an 8 to 21 node isoparametric element with elastic-plastic material and large deformation is presented. The formulation has been implemented in a nonlinear finite element program for the analysis of three-dimensional continuums. To demonstrate the utility of the formulation, a thick-walled cylinder was analyzed and the results are compared favorably with a known solution. The element type presented can be applied not only to 3-D continuums, but also to plate or shell structures, for which degenerated isoparametric elements may be used

  7. Novel Two- and Three-Dimensional Organometallic-Organic Hybrid Materials Based on Polyphosphorus Complexes.

    Science.gov (United States)

    Attenberger, Bianca; Peresypkina, Eugenia V; Scheer, Manfred

    2015-07-20

    The reaction of the silver salt Ag[Al{OC(CF3)3}4] (1) with the P2 ligand complex [Cp2Mo2(CO)4(η(2)-P2)] (2) and the organic ditopic linker trans-1,2-di(pyridine-4-yl)ethene (dpe) results in the formation of four novel organometallic-organic hybrid compounds. Depending on the reaction conditions, the two-dimensional networks [{Cp2Mo2(CO)4(μ4,η(1:1:2:2)-P2)}(μ,η(1:1)-C12H10N2)Ag]n[Al{OC(CF3)3}4]n·0.075nCH2Cl2·1.425nC6H6 (3) and [{Cp2Mo2(CO)4(μ3,η(2:2:2)-P2)}2(μ,η(1:1)-C12H10N2)3Ag2]n[Al{OC(CF3)3}4]2n·2nC7H8 (4) are accessible. The latter shows a two-dimensional (2D) → 2D interpenetration structure. Furthermore, the formation of a unique three-dimensional polymer [{Cp2Mo2(CO)4(μ4,η(1:1:2:2)-P2)}(μ,η(1:1)-C12H10N2)Ag]n[Al{OC(CF3)3}4]n·0.3nCH2Cl2 (5b) together with another 2D polymer [{Cp2Mo2(CO)4(μ4,η(1:1:2:2)-P2)}(μ,η(1:1)-C12H10N2)3Ag2]n[Al{OC(CF3)3}4]2n·0.75CH2Cl2·0.5C7H8 (5a) was observed. In three of these polymers, unprecedented organometallic nodes were realized including one, two, or even four silver cations. All products were characterized by X-ray structural analysis and classified by the structural characteristics in three different network topologies.

  8. Novel Two- and Three-Dimensional Organometallic–Organic Hybrid Materials Based on Polyphosphorus Complexes

    Science.gov (United States)

    2015-01-01

    The reaction of the silver salt Ag[Al{OC(CF3)3}4] (1) with the P2 ligand complex [Cp2Mo2(CO)4(η2-P2)] (2) and the organic ditopic linker trans-1,2-di(pyridine-4-yl)ethene (dpe) results in the formation of four novel organometallic–organic hybrid compounds. Depending on the reaction conditions, the two-dimensional networks [{Cp2Mo2(CO)4(μ4,η1:1:2:2-P2)}(μ,η1:1-C12H10N2)Ag]n[Al{OC(CF3)3}4]n·0.075nCH2Cl2·1.425nC6H6 (3) and [{Cp2Mo2(CO)4(μ3,η2:2:2-P2)}2(μ,η1:1-C12H10N2)3Ag2]n[Al{OC(CF3)3}4]2n·2nC7H8 (4) are accessible. The latter shows a two-dimensional (2D) → 2D interpenetration structure. Furthermore, the formation of a unique three-dimensional polymer [{Cp2Mo2(CO)4(μ4,η1:1:2:2-P2)}(μ,η1:1-C12H10N2)Ag]n[Al{OC(CF3)3}4]n·0.3nCH2Cl2 (5b) together with another 2D polymer [{Cp2Mo2(CO)4(μ4,η1:1:2:2-P2)}(μ,η1:1-C12H10N2)3Ag2]n[Al{OC(CF3)3}4]2n·0.75CH2Cl2·0.5C7H8 (5a) was observed. In three of these polymers, unprecedented organometallic nodes were realized including one, two, or even four silver cations. All products were characterized by X-ray structural analysis and classified by the structural characteristics in three different network topologies. PMID:26121218

  9. Three-Dimensional Thermomechanical Simulation and Experimental Validation on Failure of Dissimilar Material Welds

    Science.gov (United States)

    Santosh, R.; Das, S. K.; Das, G.; Korody, J.; Kumar, S.; Singh, P. K.; Ghosh, M.

    2016-07-01

    Dissimilar material weld joints, consisting of low-alloy steel and 304LN austenitic stainless steel (SS), have critical application in boiling water reactors in the nuclear industry. It was predicted that phase transformation adjacent to the fusion boundary and stress distribution across the transition joint play a key role in the structural degeneration of these welds. Quantitatively, to evaluate their contribution, two different joints were considered. One was fabricated with buttering material 309L SS (M/S Mishra Dhatu Nigam Limited, Hyderabad, India), and the other was produced with buttering material IN182 (M/S Mishra Dhatu Nigam Limited, Hyderabad, India). Base materials remained the same for both. Thermomechanical simulation on dissimilar material welds was performed using finite-element modeling to predict the thermal effect and stress prone area. Temperature-dependent thermal and structural properties were considered for simulation. Simulation results were compared with microstructural characteristics, and data were obtained from the in-situ tensile test. Simulation results exhibited that stress was at maximum in the buttering material and made the zone weaker with respect to adjacent areas. During the validation of results, it was observed that failure occurred through buttering material and endorsed the inference. The variation in mechanical properties of the two welds was explained considering the effect of thermal state and stress distribution.

  10. A new TriBeam system for three-dimensional multimodal materials analysis

    Science.gov (United States)

    Echlin, McLean P.; Mottura, Alessandro; Torbet, Christopher J.; Pollock, Tresa M.

    2012-02-01

    The unique capabilities of ultrashort pulse femtosecond lasers have been integrated with a focused ion beam (FIB) platform to create a new system for rapid 3D materials analysis. The femtosecond laser allows for in situ layer-by-layer material ablation with high material removal rates. The high pulse frequency (1 kHz) of ultrashort (150 fs) laser pulses can induce material ablation with virtually no thermal damage to the surrounding area, permitting high resolution imaging, as well as crystallographic and elemental analysis, without intermediate surface preparation or removal of the sample from the chamber. The TriBeam system combines the high resolution and broad detector capabilities of the DualBeamTM microscope with the high material removal rates of the femtosecond laser, allowing 3D datasets to be acquired at rates 4-6 orders of magnitude faster than 3D FIB datasets. Design features that permit coupling of laser and electron optics systems and positioning of a stage in the multiple analysis positions are discussed. Initial in situ multilayer data are presented.

  11. Hysteretic Four-Step Spin Crossover within a Three-Dimensional Porous Hofmann-like Material

    Energy Technology Data Exchange (ETDEWEB)

    Clements, John E.; Price, Jason R.; Neville, Suzanne M.; Kepert, Cameron J. (Sydney); (Aust. Synch.)

    2016-10-21

    Materials that display multiple stepped spin crossover (SCO) transitions with accompanying hysteresis present the opportunity for ternary, quaternary, and quinary electronic switching and data storage but are rare in existence. Herein, we present the first report of a four-step hysteretic SCO framework. Single-crystal structure analysis of a porous 3D Hofmann-like material showed long-range ordering of spin states: HS, HS0.67LS0.33, HS0.5LS0.5, HS0.33LS0.67, and LS. These detailed structural studies provide insight into how multistep SCO materials can be rationally designed through control of host–host and host–guest interactions.

  12. Three-dimensional Hierarchical Metal oxide-Carbon Electrode Material for High Efficient Microbial Electrosynthesis

    DEFF Research Database (Denmark)

    Cui, Mengmeng; Nie, Huarong; Zhang, Tian

    2017-01-01

    The production of hierarchical hybrid conductive materials that are mesoporous, with pores spanning from sub-micron to microns in size, is important for large-area electrode applications. Here, a simple one-step, low-cost method to fabricate a metal oxide-carbon hybrid materials with a hierarchical...... pore structure in a microwave oven is demonstrated. Microwave pyrolysis of ferrocene using carbon felt as a microwave absorber, a method that is rapid (tens of seconds), does not require harsh conditions nor costly equipment is utilized, and can be readily scaled up. The produced material has a high...... specific surface area, a multi-length scale porous structure and a high conductivity, and is quite stable, making it promising for many practical applications. As an electrode in microbial electrosynthesis, the performance is improved by a factor of five and an optimal biofilm of the microorganism...

  13. The performance of human dental pulp stem cells on different three-dimensional scaffold materials.

    NARCIS (Netherlands)

    Zhang, W.; Walboomers, X.F.; Kuppevelt, A.H.M.S.M. van; Daamen, W.F.; Bian, Z.; Jansen, J.A.

    2006-01-01

    The aim of this study was to investigate the in vitro and in vivo behavior of human dental pulp stem cells (DPSCs) isolated from impacted third molars, when seeded onto different 3-dimensional (3-D) scaffold materials: i.e. a spongeous collagen, a porous ceramic, and a fibrous titanium mesh.

  14. Terahertz (THz) Optical Parameters of Three-Dimensional (3-D) Printing Materials

    Science.gov (United States)

    2017-03-01

    additively created structures versus those created using standard processes , such as injection molding , casting, or machining. Terahertz (THz) radiation...nonconductive extrusion industry. Quantifying parts manufactured using additive processes is an unknown, as is understanding the material properties of...OTHER AUTHORIZED DOCUMENTS. TRADE NAMES USE OF TRADE NAMES OR MANUFACTURERS IN THIS REPORT DOES NOT CONSTITUTE AN OFFICIAL ENDORSEMENT OR

  15. Three-dimensional biomaterial degradation - Material choice, design and extrinsic factor considerations.

    Science.gov (United States)

    Yildirimer, Lara; Seifalian, Alexander M

    2014-01-01

    The apparent difficulty to precisely control fine-tuning of biomaterial degradation has initiated the recent paradigm shift from conventional top-down fabrication methods to more nature-inspired bottom-up assemblies. Sophistication of material fabrication techniques allows today's scientists to reach beyond conventional natural materials in order to synthesise tomorrow's 'designer material'. Material degradation into smaller components and subsequent release of encapsulated cells or cell-signalling agents have opened medically exploitable avenues, transforming the area of regenerative medicine into a dynamic and self-propagating branch of modern medicine. The aim to synthesise ever more refined scaffolding structures in order to create micro- and nanoenvironments resembling those found in natural tissues now represents an ever growing niche in the materials sciences. Recently, we have developed and conducted the world's first in-human tracheal transplantation using a non-degradable completely synthetic biomaterial. Fuelled by such clinical potential, we are currently developing a biodegradable version suitable for skin tissue engineering and paediatric applications. However, despite enormous efforts, current, as yet insurmountable challenges include precise biomaterial degradation within pre-determined spatial and temporal confines in an effort to release bio-signalling agents in such orchestrated fashion as to fully regenerate functioning tissues. In this review, the authors, almost anti-climactically, ask the readers to step out of the artificially over-constructed spiral of ever more convoluted scaffold fabrication techniques and consider the benefits of controllable bottom-up scaffold fabrication methods. It will further be investigated how scaffold designs and fabrication methods may influence degradation and subsequent release of incorporated elements. A focus will be placed on the delivery of growth factors, stem cells and therapeutic agents alone or in

  16. Three-dimensional imaging of nanoscale materials by using coherent x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Jianwei

    2011-04-18

    X-ray crystallography is currently the primary methodology used to determine the 3D structure of materials and macromolecules. However, many nanostructures, disordered materials, biomaterials, hybrid materials and biological specimens are noncrystalline and, hence, their structures are not accessible by X-ray crystallography. Probing these structures therefore requires the employment of different approaches. A very promising technique currently under rapid development is X-ray diffraction microscopy (or lensless imaging), in which the coherent X-ray diffraction pattern of a noncrystalline specimen is measured and then directly phased to obtain a high-resolution image. Through the DOE support over the past three years, we have applied X-ray diffraction microscopy to quantitative imaging of GaN quantum dot particles, and revealed the internal GaN-Ga2O3 core shell structure in three dimensions. By exploiting the abrupt change in the scattering cross-section near electronic resonances, we carried out the first experimental demonstration of resonant X-ray diffraction microscopy for element specific imaging. We performed nondestructive and quantitative imaging of buried Bi structures inside a Si crystal by directly phasing coherent X-ray diffraction patterns acquired below and above the Bi M5 edge. We have also applied X-ray diffraction microscopy to nondestructive imaging of mineral crystals inside biological composite materials - intramuscular fish bone - at the nanometer scale resolution. We identified mineral crystals in collagen fibrils at different stages of mineralization and proposed a dynamic mechanism to account for the nucleation and growth of mineral crystals in the collagen matrix. In addition, we have also discovered a novel 3D imaging modality, denoted ankylography, which allows for complete 3D structure determination without the necessity of sample titling or scanning. We showed that when the diffraction pattern of a finite object is sampled at a

  17. Investigating the Role of Surface Materials and Three Dimensional Architecture on In Vitro Differentiation of Porcine Monocyte-Derived Dendritic Cells

    DEFF Research Database (Denmark)

    Hartmann, Sofie Bruun; Mohanty, Soumyaranjan; Skovgaard, Kerstin

    2016-01-01

    in materials other than polystyrene and applying three-dimensional structures more similar to the in vivo environment. Polydimethylsiloxane (PDMS) is an often used polymer for lab-on-a-chip devices but not much is known about the effect of changing the culture surface material from polystyrene to PDMS......-dimensional PDMS and carbonised three-dimensional PDMS. Cells cultured conventionally (on two-dimensional polystyrene) differentiated into moDCs as expected. Interestingly, gene expression of a wide range of cytokines, chemokines, and pattern recognition receptors was influenced by culture surface material...... and architecture. Distinct clustering of cells, based on similar expression patterns of 46 genes of interest, was seen for cells isolated from two- and three-dimensional polystyrene as well as two- and three-dimensional PDMS. Changing the material from polystyrene to PDMS resulted in cells with expression patterns...

  18. Three-dimensional nanomechanical mapping of amorphous and crystalline phase transitions in phase-change materials.

    Science.gov (United States)

    Grishin, Ilja; Huey, Bryan D; Kolosov, Oleg V

    2013-11-13

    The nanostructure of micrometer-sized domains (bits) in phase-change materials (PCM) that undergo switching between amorphous and crystalline phases plays a key role in the performance of optical PCM-based memories. Here, we explore the dynamics of such phase transitions by mapping PCM nanostructures in three dimensions with nanoscale resolution by combining precision Ar ion beam cross-sectional polishing and nanomechanical ultrasonic force microscopy (UFM) mapping. Surface and bulk phase changes of laser written submicrometer to micrometer sized amorphous-to-crystalline (SET) and crystalline-to-amorphous (RESET) bits in chalcogenide Ge2Sb2Te5 PCM are observed with 10-20 nm lateral and 4 nm depth resolution. UFM mapping shows that the Young's moduli of crystalline SET bits exceed the moduli of amorphous areas by 11 ± 2%, with crystalline content extending from a few nanometers to 50 nm in depth depending on the energy of the switching pulses. The RESET bits written with 50 ps pulses reveal shallower depth penetration and show 30-50 nm lateral and few nanometer vertical wavelike topography that is anticorrelated with the elastic modulus distribution. Reverse switching of amorphous RESET bits results in the full recovery of subsurface nanomechanical properties accompanied with only partial topography recovery, resulting in surface corrugations attributed to quenching. This precision sectioning and nanomechanical mapping approach could be applicable to a wide range of amorphous, nanocrystalline, and glass-forming materials for 3D nanomechanical mapping of amorphous-crystalline transitions.

  19. Three dimensional printing technology and materials for treatment of elbow fractures.

    Science.gov (United States)

    Yang, Long; Grottkau, Brian; He, Zhixu; Ye, Chuan

    2017-11-01

    3D printing is a rapid prototyping technology that uses a 3D digital model to physically build an object. The aim of this study was to evaluate the peri-operative effect of 3D printing in treating complex elbow fractures and its role in physician-patient communication and determine which material is best for surgical model printing. Forty patients with elbow fractures were randomly divided into a 3D printing-assisted surgery group (n = 20) and a conventional surgery group (n = 20). Surgery duration, intra-operative blood loss, anatomic reduction rate, incidence of complications and elbow function score were compared between the two groups. The printing parameters, the advantages and the disadvantages of PLA and ABS were also compared. The independent-samples t-test was used to compare the data between groups. A questionnaire was designed for orthopaedic surgeons to evaluate the verisimilitude, the appearance of being true or real, and effectiveness of the 3D printing fracture model. Another questionnaire was designed to evaluate physician-patient communication effectiveness. The 3D group showed shorter surgical duration, lower blood loss and higher elbow function score, compared with the conventional group. PLA is an environmentally friendly material, whereas ABS produce an odour in the printing process. Curling edges occurred easily in the printing process with ABS and were observed in four of ten ABS models but in only one PLA model. The overall scores given by the surgeons about the verisimilitude and effectiveness of the 3D model were relatively high. Patient satisfaction scores for the 3D model were higher than those for the 2D imaging data during physician-patient discussions. 3D-printed models can accurately depict the anatomic characteristics of fracture sites, help surgeons determine a surgical plan and represent an effective tool for physician-patient communication. PLA is more suitable for desktop fused deposition printing in surgical modeling

  20. Conformal coating of thin polymer electrolyte layer on nanostructured electrode materials for three-dimensional battery applications.

    Science.gov (United States)

    Gowda, Sanketh R; Reddy, Arava Leela Mohana; Shaijumon, Manikoth M; Zhan, Xiaobo; Ci, Lijie; Ajayan, Pulickel M

    2011-01-12

    Various three-dimensional (3D) battery architectures have been proposed to address effective power delivery in micro/nanoscale devices and for increasing the stored energy per electrode footprint area. One step toward obtaining 3D configurations in batteries is the formation of core-shell nanowires that combines electrode and electrolyte materials. One of the major challenges however in creating such architectures has been the coating of conformal thin nanolayers of polymer electrolytes around nanostructured electrodes. Here we show conformal coatings of 25-30 nm poly(methyl methacralate) electrolyte layers around individual Ni-Sn nanowires used as anodes for Li ion battery. This configuration shows high discharge capacity and excellent capacity retention even at high rates over extended cycling, allowing for scalable increase in areal capacity with electrode thickness. Our results demonstrate conformal nanoscale anode-electrolyte architectures for an efficient Li ion battery system.

  1. Three-Dimensional Finite Element Simulations for the Thermal Characteristics of PCRAMs with Different Buffer Layer Materials

    International Nuclear Information System (INIS)

    Yue-Feng, Gong; Zhi-Tang, Song; Yun, Ling; Yan, Liu; Yi-Jin, Li; Song-Lin, Feng

    2010-01-01

    Simulation of the heat consumption in phase change random access memories (PCRAMs) is investigated by a three-dimensional finite element model. It is revealed that the thermal conductivity and electrical conductivity of the buffer layer are crucial in controlling the heating efficiency in RESET process. The buffer layer materials W, TiN, WO 3 , TiO 2 and poly-germanium (poly-Ge) are applied in the simulation respectively, and compared with each other. The simulation results show that limitation of electrical conductivity is effective on heating efficiency and the limitation of thermal conductivity is important on the reliable RESET process. (cross-disciplinary physics and related areas of science and technology)

  2. One-step pyrolysis route to three dimensional nitrogen-doped porous carbon as anode materials for microbial fuel cells

    Science.gov (United States)

    Bi, Linlin; Ci, Suqin; Cai, Pingwei; Li, Hao; Wen, Zhenhai

    2018-01-01

    The design and synthesis of low-cost and favourable anode materials is crucial to both power production efficiency and overall performance of microbial fuel cells (MFCs). Herein, we reported the preparation of three dimensional (3D) nitrogen-doped porous carbons (N/PCs) by one-step pyrolysis of solid mixture of sodium citrate and melamine. a variety of techniques, including electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), etc., were applied to characterize the surface physicochemical properties of the products, featuring macroporous structure with rich nitrogen doping on the as-prepared N/PCs. When applied as anode materials of MFC, the N/PCs exhibits a maximum power density of 2777.7 mW m-2, approximately twice higher than that of the MFCs with the commercial carbon cloth (CC) as anode. The significantly improved performance of the N/PCs was attributed to the unique structure and properties, such as favourable porous structure, good electrical conductivity, and large pore volume (0.7 cm3 g-1) in the present N/PCs. Nitrogen dopant on the surface of porous carbon contributed to an increasing in biocompatibility, resulting in a suitable micro-environment for microbial growth and thus helps to decrease charge transfer resistance at the electrode interface.

  3. Three-Dimensional SnS Decorated Carbon Nano-Networks as Anode Materials for Lithium and Sodium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Yanli Zhou

    2018-02-01

    Full Text Available The three-dimensional (3D SnS decorated carbon nano-networks (SnS@C were synthesized via a facile two-step method of freeze-drying combined with post-heat treatment. The lithium and sodium storage performances of above composites acting as anode materials were investigated. As anode materials for lithium ion batteries, a high reversible capacity of 780 mAh·g−1 for SnS@C composites can be obtained at 100 mA·g−1 after 100 cycles. Even cycled at a high current density of 2 A·g−1, the reversible capacity of this composite can be maintained at 610 mAh·g−1 after 1000 cycles. The initial charge capacity for sodium ion batteries can reach 333 mAh·g−1, and it retains a reversible capacity of 186 mAh·g−1 at 100 mA·g−1 after 100 cycles. The good lithium or sodium storage performances are likely attributed to the synergistic effects of the conductive carbon nano-networks and small SnS nanoparticles.

  4. Semi-automated delineation of breast cancer tumors and subsequent materialization using three-dimensional printing (rapid prototyping).

    Science.gov (United States)

    Schulz-Wendtland, Rüdiger; Harz, Markus; Meier-Meitinger, Martina; Brehm, Barbara; Wacker, Till; Hahn, Horst K; Wagner, Florian; Wittenberg, Thomas; Beckmann, Matthias W; Uder, Michael; Fasching, Peter A; Emons, Julius

    2017-03-01

    Three-dimensional (3D) printing has become widely available, and a few cases of its use in clinical practice have been described. The aim of this study was to explore facilities for the semi-automated delineation of breast cancer tumors and to assess the feasibility of 3D printing of breast cancer tumors. In a case series of five patients, different 3D imaging methods-magnetic resonance imaging (MRI), digital breast tomosynthesis (DBT), and 3D ultrasound-were used to capture 3D data for breast cancer tumors. The volumes of the breast tumors were calculated to assess the comparability of the breast tumor models, and the MRI information was used to render models on a commercially available 3D printer to materialize the tumors. The tumor volumes calculated from the different 3D methods appeared to be comparable. Tumor models with volumes between 325 mm 3 and 7,770 mm 3 were printed and compared with the models rendered from MRI. The materialization of the tumors reflected the computer models of them. 3D printing (rapid prototyping) appears to be feasible. Scenarios for the clinical use of the technology might include presenting the model to the surgeon to provide a better understanding of the tumor's spatial characteristics in the breast, in order to improve decision-making in relation to neoadjuvant chemotherapy or surgical approaches. J. Surg. Oncol. 2017;115:238-242. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Three dimensional system integration

    CERN Document Server

    Papanikolaou, Antonis; Radojcic, Riko

    2010-01-01

    Three-dimensional (3D) integrated circuit (IC) stacking is the next big step in electronic system integration. It enables packing more functionality, as well as integration of heterogeneous materials, devices, and signals, in the same space (volume). This results in consumer electronics (e.g., mobile, handheld devices) which can run more powerful applications, such as full-length movies and 3D games, with longer battery life. This technology is so promising that it is expected to be a mainstream technology a few years from now, less than 10-15 years from its original conception. To achieve thi

  6. Three-dimensional metamaterials

    Science.gov (United States)

    Burckel, David Bruce [Albuquerque, NM

    2012-06-12

    A fabrication method is capable of creating canonical metamaterial structures arrayed in a three-dimensional geometry. The method uses a membrane suspended over a cavity with predefined pattern as a directional evaporation mask. Metallic and/or dielectric material can be evaporated at high vacuum through the patterned membrane to deposit resonator structures on the interior walls of the cavity, thereby providing a unit cell of micron-scale dimension. The method can produce volumetric metamaterial structures comprising layers of such unit cells of resonator structures.

  7. Fabrication of a radiopaque fit-testing material to evaluate the three-dimensional accuracy of dental prostheses.

    Science.gov (United States)

    Oka, Yuzo; Sasaki, Jun-Ichi; Wakabayashi, Kazumichi; Nakano, Yoshiro; Okamura, Shin-Ya; Nakamura, Takashi; Imazato, Satoshi; Yatani, Hirofumi

    2016-07-01

    The objective of this study was to fabricate a radiopaque prosthetic fit-testing material, and to develop methodology to evaluate the fitting accuracy of prostheses three-dimensionally (3D) using a combination of the silicone replica technique and micro-computed tomography (μCT). Eight types of prototype specimens of fit-testing materials were prepared by adding contrast agents (zirconia, alumina, and barium-glass) to a commercially available fit-testing material. These specimens were evaluated on their mechanical properties, X-ray absorption coefficients, reproducibility of cement space, and suitability for 3D analysis by μCT. Then, silicone replicas made from prototype specimens were assessed for accurate 3D morphology. Subsequently, color-mapping analyses of the silicone replicas were performed according to replica thickness, and the results were compared with stereomicroscopic images. The mechanical properties, X-ray absorption coefficients, and reproducibility of the cement space demonstrated that prototypes containing 20wt% zirconia (Zr-20) or barium glass (diameter 2μm; Ba2-20) were useful as fit-testing materials. However, the morphology of the Ba2-20 silicone replica was unable to be accurately described using μCT because of its low X-ray absorption threshold. Zr-20, however, could be clearly observed on μCT imaging. Furthermore, color-mapping analysis of the μCT images demonstrated that Zr-20 was the most suitable for 3D observation of prosthetic fit. This method could allow any professional to evaluate the fit of any type of dental prosthesis, such as inlays, crowns, and fixed and removable dentures. This study demonstrated that the technique presented in the current study is able to accurately describe the abutment-crown prosthetic discrepancy based on silicone replicas. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. A three-dimensional vertically aligned functionalized multilayer graphene architecture: an approach for graphene-based thermal interfacial materials.

    Science.gov (United States)

    Liang, Qizhen; Yao, Xuxia; Wang, Wei; Liu, Yan; Wong, Ching Ping

    2011-03-22

    Thermally conductive functionalized multilayer graphene sheets (fMGs) are efficiently aligned in large-scale by a vacuum filtration method at room temperature, as evidenced by SEM images and polarized Raman spectroscopy. A remarkably strong anisotropy in properties of aligned fMGs is observed. High electrical (∼386 S cm(-1)) and thermal conductivity (∼112 W m(-1) K(-1) at 25 °C) and ultralow coefficient of thermal expansion (∼-0.71 ppm K(-1)) in the in-plane direction of A-fMGs are obtained without any reduction process. Aligned fMGs are vertically assembled between contacted silicon/silicon surfaces with pure indium as a metallic medium. Thus-constructed three-dimensional vertically aligned fMG thermal interfacial material (VA-fMG TIM) architecture has significantly higher equivalent thermal conductivity (75.5 W m(-1) K(-1)) and lower contact thermal resistance (5.1 mm2 K W(-1)), compared with their counterpart from A-fMGs that are recumbent between silicon surfaces. This finding provides a throughout approach for a graphene-based TIM assembly as well as knowledge of vertically aligned graphene architectures, which may not only facilitate graphene's application in current demanding thermal management but also promote its widespread applications in electrodes of energy storage devices, conductive polymeric composites, etc.

  9. Two iridates, two models, and two approaches: A comparative study on magnetism in three-dimensional honeycomb materials

    Science.gov (United States)

    Lee, Eric Kin-Ho; Rau, Jeffrey G.; Kim, Yong Baek

    2016-05-01

    Two recent theoretical works studied the role of Kitaev interactions in the newly observed incommensurate magnetic order in the hyper-honeycomb (β -Li2IrO3 ) and stripy-honeycomb (γ -Li2IrO3 ) iridates. Each of these works analyzed a different model (J K Γ versus coupled zigzag chain model) using a contrasting method (classical versus soft-spin analysis). The lack of commonality between these works precludes meaningful comparisons and a proper understanding of these unusual orderings. In this study, we complete the unfinished picture initiated by these two works by solving both models with both approaches for both three-dimensional (3D) honeycomb iridates. Through comparisons between all combinations of models, techniques, and materials, we find that the bond-isotropic J K Γ model consistently predicts the experimental phase of β -Li2IrO3 regardless of the method used, while the experimental phase of γ -Li2IrO3 can be generated by the soft-spin approach with eigenmode mixing irrespective of the model used. To gain further insights, we solve a one-dimensional (1D) quantum spin-chain model related to both 3D models using the density matrix renormalization group method to form a benchmark. We discover that in the 1D model, incommensurate correlations in the classical and soft-spin analysis survive in the quantum limit only in the presence of the symmetric-off-diagonal exchange Γ found in the J K Γ model. The relevance of these results to the real materials is also discussed.

  10. Three-dimensional printing of X-ray computed tomography datasets with multiple materials using open-source data processing.

    Science.gov (United States)

    Sander, Ian M; McGoldrick, Matthew T; Helms, My N; Betts, Aislinn; van Avermaete, Anthony; Owers, Elizabeth; Doney, Evan; Liepert, Taimi; Niebur, Glen; Liepert, Douglas; Leevy, W Matthew

    2017-07-01

    Advances in three-dimensional (3D) printing allow for digital files to be turned into a "printed" physical product. For example, complex anatomical models derived from clinical or pre-clinical X-ray computed tomography (CT) data of patients or research specimens can be constructed using various printable materials. Although 3D printing has the potential to advance learning, many academic programs have been slow to adopt its use in the classroom despite increased availability of the equipment and digital databases already established for educational use. Herein, a protocol is reported for the production of enlarged bone core and accurate representation of human sinus passages in a 3D printed format using entirely consumer-grade printers and a combination of free-software platforms. The comparative resolutions of three surface rendering programs were also determined using the sinuses, a human body, and a human wrist data files to compare the abilities of different software available for surface map generation of biomedical data. Data shows that 3D Slicer provided highest compatibility and surface resolution for anatomical 3D printing. Generated surface maps were then 3D printed via fused deposition modeling (FDM printing). In conclusion, a methodological approach that explains the production of anatomical models using entirely consumer-grade, fused deposition modeling machines, and a combination of free software platforms is presented in this report. The methods outlined will facilitate the incorporation of 3D printed anatomical models in the classroom. Anat Sci Educ 10: 383-391. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

  11. Electrostatic Spray Deposition-Based Manganese Oxide Films—From Pseudocapacitive Charge Storage Materials to Three-Dimensional Microelectrode Integrands

    Directory of Open Access Journals (Sweden)

    Richa Agrawal

    2017-07-01

    Full Text Available In this study, porous manganese oxide (MnOx thin films were synthesized via electrostatic spray deposition (ESD and evaluated as pseudocapacitive electrode materials in neutral aqueous media. Very interestingly, the gravimetric specific capacitance of the ESD-based electrodes underwent a marked enhancement upon electrochemical cycling, from 72 F∙g−1 to 225 F∙g−1, with a concomitant improvement in kinetics and conductivity. The change in capacitance and resistivity is attributed to a partial electrochemical phase transformation from the spinel-type hausmannite Mn3O4 to the conducting layered birnessite MnO2. Furthermore, the films were able to retain 88.4% of the maximal capacitance after 1000 cycles. Upon verifying the viability of the manganese oxide films for pseudocapacitive applications, the thin films were integrated onto carbon micro-pillars created via carbon microelectromechanical systems (C-MEMS for examining their application as potential microelectrode candidates. In a symmetric two-electrode cell setup, the MnOx/C-MEMS microelectrodes were able to deliver specific capacitances as high as 0.055 F∙cm−2 and stack capacitances as high as 7.4 F·cm−3, with maximal stack energy and power densities of 0.51 mWh·cm−3 and 28.3 mW·cm−3, respectively. The excellent areal capacitance of the MnOx-MEs is attributed to the pseudocapacitive MnOx as well as the three-dimensional architectural framework provided by the carbon micro-pillars.

  12. Beating the wavelength limit: three-dimensional imaging of buried subwavelength fractures in sculpture and construction materials by terahertz time-domain reflection spectroscopy.

    Science.gov (United States)

    Schwerdtfeger, M; Castro-Camus, E; Krügener, K; Viöl, W; Koch, M

    2013-01-20

    We use reflection terahertz spectroscopy to locate and produce three-dimensional images of air gaps between stones that resemble fractures, even of subwavelength thicknesses. This technique is found to be promising tool for sculpture and building damage evaluation as well as structural quality control in other dielectric materials.

  13. Investigating the Role of Surface Materials and Three Dimensional Architecture on In Vitro Differentiation of Porcine Monocyte-Derived Dendritic Cells.

    Directory of Open Access Journals (Sweden)

    Sofie Bruun Hartmann

    Full Text Available In vitro generation of dendritic-like cells through differentiation of peripheral blood monocytes is typically done using two-dimensional polystyrene culture plates. In the process of optimising cell culture techniques, engineers have developed fluidic micro-devises usually manufactured in materials other than polystyrene and applying three-dimensional structures more similar to the in vivo environment. Polydimethylsiloxane (PDMS is an often used polymer for lab-on-a-chip devices but not much is known about the effect of changing the culture surface material from polystyrene to PDMS. In the present study the differentiation of porcine monocytes to monocyte-derived dendritic cells (moDCs was investigated using CD172apos pig blood monocytes stimulated with GM-CSF and IL-4. Monocytes were cultured on surfaces made of two- and three-dimensional polystyrene as well as two- and three-dimensional PDMS and carbonised three-dimensional PDMS. Cells cultured conventionally (on two-dimensional polystyrene differentiated into moDCs as expected. Interestingly, gene expression of a wide range of cytokines, chemokines, and pattern recognition receptors was influenced by culture surface material and architecture. Distinct clustering of cells, based on similar expression patterns of 46 genes of interest, was seen for cells isolated from two- and three-dimensional polystyrene as well as two- and three-dimensional PDMS. Changing the material from polystyrene to PDMS resulted in cells with expression patterns usually associated with macrophage expression (upregulation of CD163 and downregulation of CD1a, FLT3, LAMP3 and BATF3. However, this was purely based on gene expression level, and no functional assays were included in this study which would be necessary in order to classify the cells as being macrophages. When changing to three-dimensional culture the cells became increasingly activated in terms of IL6, IL8, IL10 and CCR5 gene expression. Further stimulation

  14. User's manual for three dimensional FDTD version C code for scattering from frequency-independent dielectric and magnetic materials

    Science.gov (United States)

    Beggs, John H.; Luebbers, Raymond J.; Kunz, Karl S.

    1992-01-01

    The Penn State Finite Difference Time Domain Electromagnetic Scattering Code Version C is a three-dimensional numerical electromagnetic scattering code based on the Finite Difference Time Domain (FDTD) technique. The supplied version of the code is one version of our current three-dimensional FDTD code set. The manual given here provides a description of the code and corresponding results for several scattering problems. The manual is organized into 14 sections: introduction, description of the FDTD method, operation, resource requirements, Version C code capabilities, a brief description of the default scattering geometry, a brief description of each subroutine, a description of the include file (COMMONC.FOR), a section briefly discussing radar cross section computations, a section discussing some scattering results, a new problem checklist, references, and figure titles.

  15. Development of three-dimensional trajectory model for detecting source region of the radioactive materials released into the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Kyung Suk; Park, Ki Hyun; Min, Byung Il; Kim, Sora; Yang, Byung Mo [Nuclear Environmental Safety Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-05-15

    It is necessary to consider the overall countermeasure for analysis of nuclear activities according to the increase of the nuclear facilities like nuclear power and reprocessing plants in the neighboring countries including China, Taiwan, North Korea, Japan and South Korea. South Korea and comprehensive nuclear-test-ban treaty organization (CTBTO) are now operating the monitoring instruments to detect radionuclides released into the air. It is important to estimate the origin of radionuclides measured using the detection technology as well as the monitoring analysis in aspects of investigation and security of the nuclear activities in neighboring countries. A three-dimensional forward/backward trajectory model has been developed to estimate the origin of radionuclides for a covert nuclear activity. The developed trajectory model was composed of forward and backward modules to track the particle positions using finite difference method. A three-dimensional trajectory model was validated using the measured data at Chernobyl accident. The calculated results showed a good agreement by using the high concentration measurements and the locations where was near a release point. The three-dimensional trajectory model had some uncertainty according to the release time, release height and time interval of the trajectory at each release points. An atmospheric dispersion model called long-range accident dose assessment system (LADAS), based on the fields of regards (FOR) technique, was applied to reduce the uncertainties of the trajectory model and to improve the detective technology for estimating the radioisotopes emission area. The detective technology developed in this study can evaluate in release area and origin for covert nuclear activities based on measured radioisotopes at monitoring stations, and it might play critical tool to improve the ability of the nuclear safety field.

  16. Development of three-dimensional trajectory model for detecting source region of the radioactive materials released into the atmosphere

    International Nuclear Information System (INIS)

    Suh, Kyung Suk; Park, Ki Hyun; Min, Byung Il; Kim, Sora; Yang, Byung Mo

    2016-01-01

    It is necessary to consider the overall countermeasure for analysis of nuclear activities according to the increase of the nuclear facilities like nuclear power and reprocessing plants in the neighboring countries including China, Taiwan, North Korea, Japan and South Korea. South Korea and comprehensive nuclear-test-ban treaty organization (CTBTO) are now operating the monitoring instruments to detect radionuclides released into the air. It is important to estimate the origin of radionuclides measured using the detection technology as well as the monitoring analysis in aspects of investigation and security of the nuclear activities in neighboring countries. A three-dimensional forward/backward trajectory model has been developed to estimate the origin of radionuclides for a covert nuclear activity. The developed trajectory model was composed of forward and backward modules to track the particle positions using finite difference method. A three-dimensional trajectory model was validated using the measured data at Chernobyl accident. The calculated results showed a good agreement by using the high concentration measurements and the locations where was near a release point. The three-dimensional trajectory model had some uncertainty according to the release time, release height and time interval of the trajectory at each release points. An atmospheric dispersion model called long-range accident dose assessment system (LADAS), based on the fields of regards (FOR) technique, was applied to reduce the uncertainties of the trajectory model and to improve the detective technology for estimating the radioisotopes emission area. The detective technology developed in this study can evaluate in release area and origin for covert nuclear activities based on measured radioisotopes at monitoring stations, and it might play critical tool to improve the ability of the nuclear safety field

  17. Three-dimensional echocardiography

    International Nuclear Information System (INIS)

    Buck, Thomas

    2011-01-01

    Presents tips and tricks for beginners and experts Provides educational material for 3D training courses Features comprehensively illustrated cases Includes an accompanying DVD with video clips of all sample cases Three-dimensional echocardiography is the most recent fundamental advancement in echocardiography. Since real-time 3D echocardiography became commercially available in 2002, it has rapidly been accepted in echo labs worldwide. This book covers all clinically relevant aspects of this fascinating new technology, including a comprehensive explanation of its basic principles, practical aspects of clinical application, and detailed descriptions of specific uses in the broad spectrum of clinically important heart disease. The book was written by a group of well-recognized international experts in the field, who have not only been involved in the scientific and clinical evolution of 3D echocardiography since its inception but are also intensively involved in expert training courses. As a result, the clear focus of this book is on the practical application of 3D echocardiography in daily clinical routine with tips and tricks for both beginners and experts, accompanied by more than 150 case examples comprehensively illustrated in more than 800 images and more than 500 videos provided on a DVD. In addition to an in-depth review of the most recent literature on real-time 3D echocardiography, this book represents an invaluable reference work for beginners and expert users of 3D echocardiography. - Tips and tricks for beginners and experts - Educational material for 3D training courses - Comprehensively illustrated cases - DVD with video clips of all sample cases.

  18. Three-dimensional neuroimaging

    International Nuclear Information System (INIS)

    Toga, A.W.

    1990-01-01

    This book reports on new neuroimaging technologies that are revolutionizing the study of the brain be enabling investigators to visualize its structure and entire pattern of functional activity in three dimensions. The book provides a theoretical and practical explanation of the new science of creating three-dimensional computer images of the brain. The coverage includes a review of the technology and methodology of neuroimaging, the instrumentation and procedures, issues of quantification, analytic protocols, and descriptions of neuroimaging systems. Examples are given to illustrate the use of three-dimensional enuroimaging to quantitate spatial measurements, perform analysis of autoradiographic and histological studies, and study the relationship between brain structure and function

  19. Self-destruction of three-dimensional modern paintings caused by untypical materials – finding conservation solutions.

    Directory of Open Access Journals (Sweden)

    Katarzyna Mikstal

    2012-06-01

    Full Text Available The aim of this article is to indicate the relation between matter and an idea within a work of art – three-dimensional painting which involves untypical and undurable techniques. The essay introduces the problem of retaining the idea throughout the proper preserving of the substance while taking considerable care of its authenticity and complying with the rules of restoration ethical code. The author suggests solutions for working with non-standard objects which are exposed to destruction to a much bigger extent than traditional, flateasel painting.Le but de cet article est de souligner la relation entre la matière et l’idée dans une oeuvre d'art – en particulier la peinture tridimensionnelle qui implique des techniques atypiques et non durables. L'étude met en évidence le problème de conserver l'idée lors de la préservation de la substance, en prenant veillant à l’authenticité et en respectant les règles déontologiques de la restauration. L'auteur suggère des solutions pour travailler sur ces objets échappant aux standards traditionnels, et exposés dans une plus grande mesure à la destruction qu’une peinture de chevalet bi-dimensionnelle.

  20. Three-dimensional graphene-like carbon frameworks as a new electrode material for electrochemical determination of small biomolecules.

    Science.gov (United States)

    Deng, Wenfang; Yuan, Xiaoyan; Tan, Yueming; Ma, Ming; Xie, Qingji

    2016-11-15

    Three-dimensional (3D) graphene-like carbon frameworks (3DGLCFs) were facilely prepared via copyrolysis of polyaniline and nickel nitrate powder, followed by acid etching. The as-prepared 3DGLCFs possess graphene-like network structure, high specific surface area, and high content nitrogen dopant. Because these features enable large electrochemically active surface area, rapid electron transfer, and fast transport of analytes to electrode surface, the 3DGLCFs modified glassy carbon electrode (GCE) shows current response much higher than commercial graphene (CG) modified GCE towards the oxidation of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The anodic peak separations at 3DGLCFs/GCE are 0.23V between AA and DA, 0.13V between DA and UA, and 0.36V between AA and UA. For the simultaneous electrochemical determination of AA, DA and UA using differential pulse voltammetry, the 3DGLCFs/GCE shows linear response ranges of 1.25×10(-5)-4×10(-4)M for AA, 5×10(-8)-1.0×10(-5)M for DA, and 5×10(-8)-1.5×10(-5)M for UA, with low detection limits of 2×10(-6)M for AA, 1×10(-8)M for DA, and 1×10(-8)M for UA. The 3DGLCFs/GCE was also applied for the measurement of human serum, exhibiting satisfactory recoveries. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Three-dimensional fabric analysis for anisotropic material using multi-directional scanning line. Application to x-ray CI image

    International Nuclear Information System (INIS)

    Takemura, Takato; Takahashi, Manabu; Oda, Masanobu; Hirai, Hidekazu; Murakoshi, Atsushi; Miura, Makoto

    2007-01-01

    In microscopic analysis, materials are characterized by a three-dimensional (3D) microstructure which is composed of constituent elements such as pores, voids and cracks. A material's mechanical and hydrological properties are strongly dependent on its microstructure. In order to discuss the mechanics of geomaterials on a microstructural level, detailed information on their 3D macrostructure is required. X-ray computed tomography is a powerful non-destructive method for determining the microstructure, however it can be difficult to determine a material's microstructure from the reconstructed 3D image. We successfully evaluated the 3D microstructural anisotropy of porous and fibrous materials using a multi-directional scanning line method that employs straightforward image analysis, and its results were visualized using stereonet projection. (author)

  2. Investigation of electronic band structure and charge transfer mechanism of oxidized three-dimensional graphene as metal-free anodes material for dye sensitized solar cell application

    Science.gov (United States)

    Loeblein, Manuela; Bruno, Annalisa; Loh, G. C.; Bolker, Asaf; Saguy, Cecile; Antila, Liisa; Tsang, Siu Hon; Teo, Edwin Hang Tong

    2017-10-01

    Dye-sensitized solar cells (DSSCs) offer an optimal trade-off between conversion-efficiency and low-cost fabrication. However, since all its electrodes need to fulfill stringent work-function requirements, its materials have remained unchanged since DSSC's first report early-90s. Here we describe a new material, oxidized-three-dimensional-graphene (o-3D-C), with a band gap of 0.2 eV and suitable electronic band-structure as alternative metal-free material for DSSCs-anodes. o-3D-C/dye-complex has a strong chemical bonding via carboxylic-group chemisorption with full saturation after 12 sec at capacity of ∼450 mg/g (600x faster and 7x higher than optimized metal surfaces). Furthermore, fluorescence quenching of life-time by 28-35% was measured demonstrating charge-transfer from dye to o-3D-C.

  3. Three-Dimensional Digital Evaluation of the Fit of Endocrowns Fabricated from Different CAD/CAM Materials.

    Science.gov (United States)

    Zimmermann, Moritz; Valcanaia, Andre; Neiva, Gisele; Mehl, Albert; Fasbinder, Dennis

    2018-03-06

    A wide variety of CAD/CAM materials are available for single-tooth restorations. CAD/CAM material characteristics are different and may influence CAM fabrication accuracy. There is no study investigating the influence of different CAD/CAM materials on the final fit of the restoration. The aim of this study was to evaluate the fit of endocrowns fabricated from different CAD/CAM materials using a new 3D evaluation method with an intraoral scanning system. The null hypothesis was that there are no significant differences for the fitting accuracy of different CAD/CAM materials. Preparation for an endocrown was performed on a maxillary right first molar on a typodont, and restorations were fabricated with a chairside CAD/CAM system (CEREC Omnicam, MCXL). Three groups using three different CAD/CAM materials were established (each n = 10): zirconia-reinforced lithium silicate ceramic (Celtra Duo; CD), leucite-reinforced silicate ceramic (Empress CAD; EM), resin nanoceramic (Lava Ultimate; LU). A 3D digital measurement technique (OraCheck, Cyfex AG) using an intraoral scanner (CEREC Omnicam) was used to measure the difference in fit between the three materials for a master endocrown preparation. The preparation scan and the endocrown fit scan were matched with special difference analysis software OraCheck. Three areas were selected for fitting accuracy measurements: margin (MA), axial (AX), occlusal (OC). Statistical analysis was performed using 80% percentile, one-way ANOVA, and post-hoc Scheffé test. Significance level was set to p = 0.05. Results varied from best 88.9 ± 7.7 μm for marginal fit of resin nanoceramic restorations (LU_MA) to worst 182.3 ± 24.0 μm for occlusal fit of zirconia-reinforced lithium silicate restorations (CD_OC). Statistically significant differences were found both within and among the test groups. Group CD performed statistically significantly different from group LU for marginal fit (MA) and axial fit (AX) (p 0.05). Deviation pattern for

  4. Three-Dimensional Flows

    CERN Document Server

    Araujo, Vitor; Viana, Marcelo

    2010-01-01

    In this book, the authors present the elements of a general theory for flows on three-dimensional compact boundaryless manifolds, encompassing flows with equilibria accumulated by regular orbits. The book aims to provide a global perspective of this theory and make it easier for the reader to digest the growing literature on this subject. This is not the first book on the subject of dynamical systems, but there are distinct aspects which together make this book unique. Firstly, this book treats mostly continuous time dynamical systems, instead of its discrete counterpart, exhaustively treated

  5. Portable magnetic tweezers device enables visualization of the three-dimensional microscale deformation of soft biological materials.

    Science.gov (United States)

    Yang, Yali; Lin, Jun; Meschewski, Ryan; Watson, Erin; Valentine, Megan T

    2011-07-01

    We have designed and built a magnetic tweezers device that enables the application of calibrated stresses to soft materials while simultaneously measuring their microscale deformation using confocal microscopy. Unlike previous magnetic tweezers designs, our device is entirely portable, allowing easy use on microscopes in core imaging facilities or in collaborators' laboratories. The imaging capabilities of the microscope are unimpaired, enabling the 3-D structures of fluorescently labeled materials to be precisely determined under applied load. With this device, we can apply a large range of forces (~1-1200 pN) over micron-scale contact areas to beads that are either embedded within 3-D matrices or attached to the surface of thin slab gels. To demonstrate the usefulness of this instrument, we have studied two important and biologically relevant materials: polyacrylamide-based hydrogel films typical of those used in cell traction force microscopy, and reconstituted networks of microtubules, essential cytoskeletal filaments.

  6. Comparative three-dimensional finite element analysis of implant-supported fixed complete arch mandibular prostheses in two materials

    Directory of Open Access Journals (Sweden)

    João Paulo Mendes Tribst

    2017-01-01

    Conclusions: The stress generated in all constituents of the system was not significantly influenced by the framework's material. This allows suggesting that in cases without components, the use of a framework in zirconia has biomechanical behavior similar to that of a Ti bar.

  7. Comparative three-dimensional finite element analysis of implant-supported fixed complete arch mandibular prostheses in two materials.

    Science.gov (United States)

    Tribst, João Paulo Mendes; de Morais, Dayana Campanelli; Alonso, Alexandre Abhdala; Piva, Amanda Maria de Oliveira Dal; Borges, Alexandre Luis Souto

    2017-01-01

    The increase of requests for implant-supported prosthesis (ISP) with zirconia as infrastructure has attracted a lot of attention due to its esthetics, biocompatibility, and survival rate similar to metallic infrastructure. The aim of this study was to evaluate the influence of two different framework materials on stress distribution over a bone tissue-simulating material. Two ISP were modeled and divided into two infrastructure materials: titanium (Ti) and zirconia. Then, these bars were attached to a modeled jaw with polyurethane properties to simulate bone tissue. An axial load of 200 N was applied on a standardized area for both systems. Maximum principal stress (MPS) on solids and microstrain (MS) generated through the jaw were analyzed by finite element analysis. According to MS, both models showed strains on peri-implant region of the penultimate (same side of the load application) and central implants. For MPS, more stress concentration was slightly higher in the left posterior region for Ti's bar. In prosthetic fixation screws, the MPS prevailed strongly in Ti protocol, while for zirconia's bar, the cervical of the penultimate implant was the one that highlighted larger areas of possible damages. The stress generated in all constituents of the system was not significantly influenced by the framework's material. This allows suggesting that in cases without components, the use of a framework in zirconia has biomechanical behavior similar to that of a Ti bar.

  8. Highly efficient hybrid photovoltaics based on hyperbranched three-dimensional TiO2 electron transporting materials

    KAUST Repository

    Mahmood, Khalid

    2015-03-23

    A 3D hyperbranched TiO2 electron transporting material is demonstrated, which exhibits superior carrier transport and lifetime, as well as excellent infiltration, leading to highly efficient mesostructured hybrid solar cells, such as lead-halide perovskites (15.5%) and dye-sensitized solar cells (11.2%).

  9. Three-dimensional finite element analysis of molars with thin-walled prosthetic crowns made of various materials.

    Science.gov (United States)

    Dejak, Beata; Młotkowski, Andrzej; Langot, Cezary

    2012-04-01

    The aim of the study was to compare the strength of thin-walled molar crowns made of various materials under simulation of mastication. Five 3D FE models of the first lower molar with the use of contact elements were created: intact tooth; tooth with a zirconia crown; tooth with a porcelain crown; tooth with a gold alloy crown and tooth with a composite crown. The computer simulations of mastication were conducted. For the models, equivalent stresseswere calculated using the modified von Mises failure criterion (mvM). Contact stresses at the adhesive interface between the cement and tooth structure under the crowns were analyzed. Equivalent stresses in the crowns, did not exceed the tensile strength of their material. The mvM stresses in resin cement under the zirconia crown were 1.3 MPa, and under the composite crown they increased over 6 times. The tensile and shear contact stressesunder the stiff crowns (ceramics and gold alloy), were several times lower than those under the composite one. The maximum mvM stresses in the tooth structure for the zirconia crown were only 2.8 MPa, whereas for the composite crown were 6.4 MPa. The higher elastic modulus the crown was, the lower the equivalent stresses occurred in the composite luting cement and in the tooth structures. Also contact stresses decreased with the increasing stiffness of the crowns. Under physiological loads, the thin-walled crowns perfectly luted to molars, made of zirconia ceramic, gold alloys and composite resin are resistant to failure. Prosthetic crowns made of stiff materials are less prone to debonding than those made of composite resin. Prosthetic crowns made of a material with a higher elastic modulus than enamel will strengthen the dental structures of molar teeth. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  10. Quantitative evaluation of ultrasonic C-scan image in acoustically homogeneous and layered anisotropic materials using three dimensional ray tracing method.

    Science.gov (United States)

    Kolkoori, Sanjeevareddy; Hoehne, Christian; Prager, Jens; Rethmeier, Michael; Kreutzbruck, Marc

    2014-02-01

    Quantitative evaluation of ultrasonic C-scan images in homogeneous and layered anisotropic austenitic materials is of general importance for understanding the influence of anisotropy on wave fields during ultrasonic non-destructive testing and evaluation of these materials. In this contribution, a three dimensional ray tracing method is presented for evaluating ultrasonic C-scan images quantitatively in general homogeneous and layered anisotropic austenitic materials. The directivity of the ultrasonic ray source in general homogeneous columnar grained anisotropic austenitic steel material (including layback orientation) is obtained in three dimensions based on Lamb's reciprocity theorem. As a prerequisite for ray tracing model, the problem of ultrasonic ray energy reflection and transmission coefficients at an interface between (a) isotropic base material and anisotropic austenitic weld material (including layback orientation), (b) two adjacent anisotropic weld metals and (c) anisotropic weld metal and isotropic base material is solved in three dimensions. The influence of columnar grain orientation and layback orientation on ultrasonic C-scan image is quantitatively analyzed in the context of ultrasonic testing of homogeneous and layered austenitic steel materials. The presented quantitative results provide valuable information during ultrasonic characterization of homogeneous and layered anisotropic austenitic steel materials. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Determining the representative volume element size for three-dimensional microstructural material characterization. Part 2: Application to experimental data

    Science.gov (United States)

    Harris, William M.; Chiu, Wilson K. S.

    2015-05-01

    Improved microstructural imaging and characterization methods have recently opened the door for quantitative evaluation of microstructures of such functional materials as solid oxide fuel cell and battery electrodes and composite gas separation membranes. Accurate quantitative characterization of these structures relies on the concept of a representative volume element (RVE) to provide a sufficiently large sample to be statistically representative of the material. In Part 1 of this work, several models were described to determine the RVE size for several common microstructural properties: volume fraction, particle size, and network contiguity. In this work, extensive synchrotron X-ray nanotomography imaging of a multiphase composite gas separation membrane is used to provide an experimental comparison to the model predictions. Results suggest that the models provide a reasonable estimate of RVE size, and can serve as a starting point for researchers planning imaging and characterization experiments.

  12. User's manual for three dimensional FDTD version D code for scattering from frequency-dependent dielectric and magnetic materials

    Science.gov (United States)

    Beggs, John H.; Luebbers, Raymond J.; Kunz, Karl S.

    1992-01-01

    The Penn State Finite Difference Time Domain Electromagnetic Scattering Code version D is a 3-D numerical electromagnetic scattering code based upon the finite difference time domain technique (FDTD). The manual provides a description of the code and corresponding results for several scattering problems. The manual is organized into 14 sections: introduction; description of the FDTD method; operation; resource requirements; version D code capabilities; a brief description of the default scattering geometry; a brief description of each subroutine; a description of the include file; a section briefly discussing Radar Cross Section computations; a section discussing some scattering results; a sample problem setup section; a new problem checklist; references and figure titles. The FDTD technique models transient electromagnetic scattering and interactions with objects of arbitrary shape and/or material composition. In the FDTD method, Maxwell's curl equations are discretized in time-space and all derivatives (temporal and spatial) are approximated by central differences.

  13. Three-dimensional transient cooling simulations of a portable electronic device using PCM (phase change materials) in multi-fin heat sink

    International Nuclear Information System (INIS)

    Wang, Yi-Hsien; Yang, Yue-Tzu

    2011-01-01

    Transient three-dimensional heat transfer numerical simulations were conducted to investigate a hybrid PCM (phase change materials) based multi-fin heat sink. Numerical computation was conducted with different amounts of fins (0 fin, 3 fins and 6 fins), various heating power level (2 W, 3 W and 4 W), different orientation tests (vertical/horizontal/slanted), and charge and discharge modes. Calculating time step (0.03 s, 0.05 s, and 0.07 s) size was discussed for transient accuracy as well. The theoretical model developed is validated by comparing numerical predictions with the available experimental data in the literature. The results showed that the transient surface temperatures are predicted with a maximum discrepancy within 10.2%. The operation temperature can be controlled well by the attendance of phase change material and the longer melting time can be conducted by using a multi-fin hybrid heat sink respectively. -- Highlights: → Electronic device cooling use phase change materials. → N-eicosane is adapted as phase change materials. → Present surface transient temperatures prediction error is within 10.2%. → Hybrid PCM-heat sink system provides stable operation temperature. → Orientation effects show independent on the phase change performance.

  14. Utility of time-resolved three-dimensional magnetic resonance digital subtraction angiography without contrast material for assessment of intracranial dural arterio-venous fistula

    International Nuclear Information System (INIS)

    Hori, Masaaki; Aoki, Shigeki; Nakanishi, Atsushi; Shimoji, Keigo; Kamagata, Koji; Houshito, Haruyoshi; Kuwatsuru, Ryohei; Oishi, Hidenori; Arai, Hajime

    2011-01-01

    Background: Intracranial dural arteriovenous fistula (DAVF) is an arteriovenous shunting disease of the dura. Magnetic resonance angiography (MRA) is expected to be a safer alternative method in evaluation of DAVF, compared with invasive intra-arterial digital subtraction angiography (IADSA). Purpose: To evaluate the diagnostic use of time-spatial labeling inversion pulse (Time-SLIP) three-dimensional (3D) magnetic resonance digital subtraction angiography (MRDSA) without contrast material in six patients with DAVF. Material and Methods: Images for 3D time-of-flight MRA, which has been a valuable tool for the diagnosis of DAVF but provide little or less hemodynamic information, and Time-SLIP 3D MRDSA, were acquired for each patient. The presence, side, and grade of the disease were evaluated according to IADSA. Results: In all patients, the presence and side of the DAVF were correctly identified by both 3D time-of-flight MRA and Time-SLIP 3D MRDSA. Cortical reflux present in a patient with a grade 2b DAVF was not detected by Time-SLIP 3D MRDSA, when compared with IADSA findings. Conclusion: Time-SLIP 3D MRDSA provides hemodynamic information without contrast material and is a useful complementary tool for diagnosis of DAVF

  15. Three dimensional energy profile:

    International Nuclear Information System (INIS)

    Kowsari, Reza; Zerriffi, Hisham

    2011-01-01

    The provision of adequate, reliable, and affordable energy has been considered as a cornerstone of development. More than one-third of the world's population has a very limited access to modern energy services and suffers from its various negative consequences. Researchers have been exploring various dimensions of household energy use in order to design strategies to provide secure access to modern energy services. However, despite more than three decades of effort, our understanding of household energy use patterns is very limited, particularly in the context of rural regions of the developing world. Through this paper, the past and the current trends in the field of energy analysis are investigated. The literature on rural energy and energy transition in developing world has been explored and the factors affecting households' decisions on energy use are listed. The and the factors affecting households' decisions on energy use are listed. The gaps identified in the literature on rural household energy analysis provide a basis for developing an alternative model that can create a more realistic view of household energy use. The three dimensional energy profile is presented as a new conceptual model for assessment of household energy use. This framework acts as a basis for building new theoretical and empirical models of rural household energy use. - Highlights: ► Reviews literature on household energy, energy transitions and decision-making in developing countries. ► Identifies gaps in rural household energy analysis and develops a new conceptual framework. ► The 3-d energy profile provides a holistic view of household energy system characteristics. ► Illustrates the use of the framework for understanding household energy transitions.

  16. Three-dimensional ICT reconstruction

    International Nuclear Information System (INIS)

    Zhang Aidong; Li Ju; Chen Fa; Sun Lingxia

    2005-01-01

    The three-dimensional ICT reconstruction method is the hot topic of recent ICT technology research. In the context, qualified visual three-dimensional ICT pictures are achieved through multi-piece two-dimensional images accumulation by, combining with thresholding method and linear interpolation. Different direction and different position images of the reconstructed pictures are got by rotation and interception respectively. The convenient and quick method is significantly instructive to more complicated three-dimensional reconstruction of ICT images. (authors)

  17. Three-dimensional ICT reconstruction

    International Nuclear Information System (INIS)

    Zhang Aidong; Li Ju; Chen Fa; Sun Lingxia

    2004-01-01

    The three-dimensional ICT reconstruction method is the hot topic of recent ICT technology research. In the context qualified visual three-dimensional ICT pictures are achieved through multi-piece two-dimensional images accumulation by order, combining with thresholding method and linear interpolation. Different direction and different position images of the reconstructed pictures are got by rotation and interception respectively. The convenient and quick method is significantly instructive to more complicated three-dimensional reconstruction of ICT images. (authors)

  18. Effect of different restorative crown and customized abutment materials on stress distribution in single implants and peripheral bone: A three-dimensional finite element analysis study.

    Science.gov (United States)

    Kaleli, Necati; Sarac, Duygu; Külünk, Safak; Öztürk, Özgür

    2018-03-01

    In recent years, the use of resin-matrix ceramics and polyetheretherketone (PEEK) abutments has been suggested to absorb excessive stresses on dental implants. However, only a few studies have evaluated the effect of these materials on stress distribution in implants and peripheral bone structure. The purpose of this finite element analysis was to evaluate the biomechanical behaviors of resin-matrix ceramics and PEEK customized abutments in terms of stress distribution in implants and peripheral bone. Three-dimensional (3D) models of a bone-level implant system and a titanium base abutment were created by using the standard tessellation language (STL) data of original implant components. An anatomic customized abutment and a maxillary right second premolar crown were then modeled over the titanium base abutment. A bone block representing the maxillary right premolar area was created, and the implant was placed in the bone block with 100% osseointegration. Six different models were created according to combinations of restoration materials (translucent zirconia [TZI], lithium disilicate glass ceramic [IPS], polymer-infiltrated hybrid ceramic [VTE]), and customized abutment materials (PEEK and zirconia). In each model, the implants were loaded vertically (200 N) and obliquely (100 N). The stress distribution in the crown, implant, and abutments was evaluated through the von Mises stress analysis, and the stress distribution in the peripheral bone was examined through the maximum and minimum principal stress analyses. The oblique load resulted in high stress values in the implant components, restorative crown, and cortical bone. Low stress values were observed in the VTE crowns. Zirconia customized abutments exhibited higher stress values than PEEK customized abutments. The stress distributions in the implant and peripheral bone were similar in all models. Changes in restoration and customized abutment material did not affect stress distribution in the implant and

  19. Magnetic solid-phase extraction using nanoporous three dimensional graphene hybrid materials for high-capacity enrichment and simultaneous detection of nine bisphenol analogs from water sample.

    Science.gov (United States)

    Wang, Lingling; Zhang, Zhenzhen; Zhang, Jing; Zhang, Lei

    2016-09-09

    The synthesis of a magnetic nanoporous three dimensional graphene (3DG)/ZnFe2O4 composite has been achieved. Through formation of graphene hydrogel, ZnFe2O4 magnetic particles was successfully introduced into the nanoporous 3DG, resulting in a magnetic porous carbon material. The morphology, structure, and magnetic behavior of the as-prepared 3DG/ZnFe2O4 were characterized by using the techniques of SEM, XRD, BET, VSM, FTIR, Raman and TGA. The 3DG/ZnFe2O4 has a high specific surface area and super paramagnetism. Its performance was evaluated by the magnetic solid-phase extraction of nine bisphenol analogs (BPs) from water samples followed by HPLC analysis, and showed excellent adsorption capability for the nine target compounds. Under optimized condition, the lower method detection limits (0.05-0.18ngmL(-1)), the higher enrichment factors (800 fold) and good recoveries (95.1-103.8%) with relative standard deviation (RSD) values less than 6.2% were achieved. The results indicated that the developed method based on the use of 3DG/ZnFe2O4 as the magnetic adsorbent has the advantages of convenience and high efficiency, and can be successfully applied to detect the nine BPs in real water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Channel shape and interpoly dielectric material effects on electrical characteristics of floating-gate-type three-dimensional fin channel flash memories

    Science.gov (United States)

    Liu, Yongxun; Nabatame, Toshihide; Nguyen, Num; Matsukawa, Takashi; Endo, Kazuhiko; O'uchi, Shinichi; Tsukada, Junichi; Yamauchi, Hiromi; Ishikawa, Yuki; Mizubayashi, Wataru; Morita, Yukinori; Migita, Shinji; Ota, Hiroyuki; Chikyow, Toyohiro; Masahara, Meishoku

    2015-04-01

    Floating-gate (FG)-type three-dimensional (3D) fin channel flash memories with triangular fin (TF) and rectangular fin (RF) channels and different interpoly dielectric (IPD) materials have been successfully fabricated using (100)- and (110)-oriented silicon-on-insulator (SOI) wafers and orientation-dependent wet etching. The electrical characteristics of the fabricated FG-type 3D fin channel flash memories including threshold voltage (Vt) variability, program/erase (P/E) speed, memory window, endurance, and data retention at room temperature and 85 °C have been comparatively investigated. A higher P/E speed, a larger memory window, and a lower-voltage operation are experimentally obtained in the TF channel flash memories with an Al2O3-nitride-oxide (ANO) IPD layer (TF-ANO) than in the RF channel ones with the same ANO IPD layer (RF-ANO) and the TF channel ones with an oxide-nitride-oxide (ONO) IPD layer (TF-ONO). The larger memory window and lower-voltage operation of TF-ANO flash memories are due to the high-k effect of the Al2O3 layer and the electric field enhancement at the sharp foot edges of the TF channels. It was also found that data retention for all fabricated FG-type 3D fin channel flash memories shows a weak dependence on temperature.

  1. Evaluation by medical students of the educational value of multi-material and multi-colored three-dimensional printed models of the upper limb for anatomical education.

    Science.gov (United States)

    Mogali, Sreenivasulu Reddy; Yeong, Wai Yee; Tan, Heang Kuan Joel; Tan, Gerald Jit Shen; Abrahams, Peter H; Zary, Nabil; Low-Beer, Naomi; Ferenczi, Michael Alan

    2018-01-01

    For centuries, cadaveric material has been the cornerstone of anatomical education. For reasons of changes in curriculum emphasis, cost, availability, expertise, and ethical concerns, several medical schools have replaced wet cadaveric specimens with plastinated prosections, plastic models, imaging, and digital models. Discussions about the qualities and limitations of these alternative teaching resources are on-going. We hypothesize that three-dimensional printed (3DP) models can replace or indeed enhance existing resources for anatomical education. A novel multi-colored and multi-material 3DP model of the upper limb was developed based on a plastinated upper limb prosection, capturing muscles, nerves, arteries and bones with a spatial resolution of ∼1 mm. This study aims to examine the educational value of the 3DP model from the learner's point of view. Students (n = 15) compared the developed 3DP models with the plastinated prosections, and provided their views on their learning experience using 3DP models using a survey and focus group discussion. Anatomical features in 3DP models were rated as accurate by all students. Several positive aspects of 3DP models were highlighted, such as the color coding by tissue type, flexibility and that less care was needed in the handling and examination of the specimen than plastinated specimens which facilitated the appreciation of relations between the anatomical structures. However, students reported that anatomical features in 3DP models are less realistic compared to the plastinated specimens. Multi-colored, multi-material 3DP models are a valuable resource for anatomical education and an excellent adjunct to wet cadaveric or plastinated prosections. Anat Sci Educ 11: 54-64. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

  2. Three-dimensional cheese-like carbon nanoarchitecture with tremendous surface area and pore construction derived from corn as superior electrode materials for supercapacitors

    Science.gov (United States)

    Gopiraman, Mayakrishnan; Deng, Dian; Kim, Byoung-Suhk; Chung, Ill-Min; Kim, Ick Soo

    2017-07-01

    Highly porous carbon nanoarchitectures (HPCNs) were derived from biomass materials, namely, corn fibers (CF), corn leafs (CL), and corn cobs (CC). We surprisingly found that by a very simple activation process the CF, CL, and CC materials can be transformed into exciting two-dimensional (2D) and three-dimensional (3D) carbon nanoarchitectures with excellent physicochemical properties. FESEM and HRTEM results confirmed a three different carbon forms (such as foams-like carbon, carbon sheets with several holes and cheese-like carbon morphology) of HPCNs. Huge surface area (2394-3475 m2/g) with excellent pore properties of HPCNs was determined by BET analysis. Well condensed graphitic plans of HPCNs were confirmed by XRD, XPS and Raman analyses. As an electrode material, HPCNs demonstrated a maximum specific capacitance (Cs) of 575 F/g in 1.0 M H2SO4 with good stability over 20,000 cycles. The CC-700 °C showed a tremendous Cs of 375 F/g even at 20000th cycles. To the best of our knowledge, this is the highest Cs by the biomass derived activated carbons in aqueous electrolytes. The CC-700 °C exhibited excellent charge-discharge behavior at various current densities (0.5-10 A g-1). Notably, CC-700 °C demonstrated an excellent Cs of 207 F/g at current density of 10 A g-1. An extraordinary change-discharge behavior was noticed at low current density of 0.5 A g-1.

  3. Three dimensional moire pattern alignment

    Science.gov (United States)

    Juday, Richard D. (Inventor)

    1991-01-01

    An apparatus is disclosed for determining three dimensional positioning relative to a predetermined point utilizing moire interference patterns such that the patterns are complementary when viewed on axis from the predetermined distance. Further, the invention includes means for determining rotational positioning in addition to three dimensional translational positioning.

  4. The Three-Dimensional Sign.

    Science.gov (United States)

    Davis, Daniel R.

    1997-01-01

    Discusses the implications of the three-dimensional sign proposed by Harris (1990) for general linguistic theory and the philosophy of language. The article places the principal characteristics of the three-dimensional sign (contextuality, cotemporality, communicational relevance, and experiential grounding) against those of the two-dimensional…

  5. Towards three-dimensional optical metamaterials

    Science.gov (United States)

    Tanaka, Takuo; Ishikawa, Atsushi

    2017-12-01

    Metamaterials have opened up the possibility of unprecedented and fascinating concepts and applications in optics and photonics. Examples include negative refraction, perfect lenses, cloaking, perfect absorbers, and so on. Since these metamaterials are man-made materials composed of sub-wavelength structures, their development strongly depends on the advancement of micro- and nano-fabrication technologies. In particular, the realization of three-dimensional metamaterials is one of the big challenges in this research field. In this review, we describe recent progress in the fabrication technologies for three-dimensional metamaterials, as well as proposed applications.

  6. Towards three-dimensional optical metamaterials.

    Science.gov (United States)

    Tanaka, Takuo; Ishikawa, Atsushi

    2017-01-01

    Metamaterials have opened up the possibility of unprecedented and fascinating concepts and applications in optics and photonics. Examples include negative refraction, perfect lenses, cloaking, perfect absorbers, and so on. Since these metamaterials are man-made materials composed of sub-wavelength structures, their development strongly depends on the advancement of micro- and nano-fabrication technologies. In particular, the realization of three-dimensional metamaterials is one of the big challenges in this research field. In this review, we describe recent progress in the fabrication technologies for three-dimensional metamaterials, as well as proposed applications.

  7. Three dimensional imaging of otoliths

    International Nuclear Information System (INIS)

    Barry, B.; Markwitz, A.; David, B.

    2008-01-01

    Otoliths are small structures in fish ears made of calcium carbonate which carry a record of the environment in which the fish live. Traditionally, in order to study their microchemistry by a scanning technique such as PIXE the otoliths have been either ground down by hand or thin sectioned to expose the otolith core. However this technique is subject to human error in judging the core position. In this study we have scanned successive layers of otoliths 50 and 100 μm apart by removing the otolith material in a lapping machine which can be set to a few μm precision. In one study by comparing data from otoliths from the two ears of a freshwater species we found that polishing by hand could miss the core and thus give misleading results as to the life cycle of the fish. In another example we showed detail in a marine species which could be used to build a three dimensional picture of the Sr distribution. (author)

  8. Thermophysical analysis for three-dimensional MHD stagnation-point flow of nano-material influenced by an exponential stretching surface

    Directory of Open Access Journals (Sweden)

    Fiaz Ur Rehman

    2018-03-01

    Full Text Available In the present paper a theoretical investigation is performed to analyze heat and mass transport enhancement of water-based nanofluid for three dimensional (3D MHD stagnation-point flow caused by an exponentially stretched surface. Water is considered as a base fluid. There are three (3 types of nanoparticles considered in this study namely, CuO (Copper oxide, Fe3O4 (Magnetite, and Al2O3 (Alumina are considered along with water. In this problem we invoked the boundary layer phenomena and suitable similarity transformation, as a result our three dimensional non-linear equations of describing current problem are transmuted into nonlinear and non-homogeneous differential equations involving ordinary derivatives. We solved the final equations by applying homotopy analysis technique. Influential outcomes of aggressing parameters involved in this study, effecting profiles of temperature field and velocity are explained in detail. Graphical results of involved parameters appearing in considered nanofluid are presented separately. It is worth mentioning that Skin-friction along x and y-direction is maximum for Copper oxide-water nanofluid and minimum for Alumina-water nanofluid. Result for local Nusselt number is maximum for Copper oxide-water nanofluid and is minimum for magnetite-water nanofluid. Keywords: Heat transfer, Nanofluids, Stagnation-point flow, Three-dimensional flow, Nano particles, Boundary layer

  9. Three-Dimensional Dynamic Loading of Sand

    Science.gov (United States)

    2011-02-01

    oading conditions exist at the bulk scale, and exam ples include planetary impact and crater formation, tectonic plate movement , ballistic im pact and...found further way from an impact event, where the bulk material does not necessarily experience uniform loading in excess of the Hugoniot elastic li...either as a collection of quartz spheres in a three-dimensional rectilinear dom ain for t he mesoscale simulations or as a single representative material

  10. Thermophysical analysis for three-dimensional MHD stagnation-point flow of nano-material influenced by an exponential stretching surface

    Science.gov (United States)

    Ur Rehman, Fiaz; Nadeem, Sohail; Ur Rehman, Hafeez; Ul Haq, Rizwan

    2018-03-01

    In the present paper a theoretical investigation is performed to analyze heat and mass transport enhancement of water-based nanofluid for three dimensional (3D) MHD stagnation-point flow caused by an exponentially stretched surface. Water is considered as a base fluid. There are three (3) types of nanoparticles considered in this study namely, CuO (Copper oxide), Fe3O4 (Magnetite), and Al2O3 (Alumina) are considered along with water. In this problem we invoked the boundary layer phenomena and suitable similarity transformation, as a result our three dimensional non-linear equations of describing current problem are transmuted into nonlinear and non-homogeneous differential equations involving ordinary derivatives. We solved the final equations by applying homotopy analysis technique. Influential outcomes of aggressing parameters involved in this study, effecting profiles of temperature field and velocity are explained in detail. Graphical results of involved parameters appearing in considered nanofluid are presented separately. It is worth mentioning that Skin-friction along x and y-direction is maximum for Copper oxide-water nanofluid and minimum for Alumina-water nanofluid. Result for local Nusselt number is maximum for Copper oxide-water nanofluid and is minimum for magnetite-water nanofluid.

  11. An internal magnetic field strategy to reuse pulverized active materials for high performance: a magnetic three-dimensional ordered macroporous TiO2/CoPt/α-Fe2O3 nanocomposite anode.

    Science.gov (United States)

    Tang, Yiping; Hong, Liang; Li, Jiquan; Hou, Guangya; Cao, Huazhen; Wu, Liankui; Zheng, Guoqu; Wu, Qingliu

    2017-05-09

    A ferromagnetic three-dimensional ordered macroporous TiO 2 /CoPt/α-Fe 2 O 3 (3DOMTCF) nanocomposite was synthesized via a sol-gel approach templated by poly(methyl methacrylate) (PMMA) microspheres. After magnetization, it exhibited an extremely high reversible capacity and a long cycle life, which were ascribed to the internal magnetic field for reusing pulverized active materials and its unique structure.

  12. Equilibrium: three-dimensional configurations

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    This chapter considers toroidal MHD configurations that are inherently three-dimensional. The motivation for investigation such complicated equilibria is that they possess the potential for providing toroidal confinement without the need of a net toroidal current. This leads to a number of advantages with respect to fusion power generation. First, the attractive feature of steady-state operation becomes more feasible since such configurations no longer require a toroidal current transformer. Second, with zero net current, one potentially dangerous class of MHD instabilities, the current-driven kink modes, is eliminated. Finally, three-dimensional configurations possess nondegenerate flux surfaces even in the absence of plasma pressure and plasma current. Although there is an enormous range of possible three-dimensional equilibria, the configurations of interest are accurately described as axisymmetric tori with superimposed helical fields; furthermore, they possess no net toroidal current. Instead, two different and less obvious restoring forces are developed: the helical sideband force and the toroidal dipole current force. Each is discussed in detail in Chapter 7. A detailed discussion of the parallel current constraint, including its physical significance, is given in section 7.2. A general analysis of helical sideband equilibria, along with a detailed description of the Elmo bumpy torus, is presented in sections 7.3 and 7.4. A general description of toroidal dipole-current equilibria, including a detailed discussion of stellarators, heliotrons, and torsatrons, is given in sections 7.5 and 7.6

  13. Three-dimensional Imaging, Visualization, and Display

    CERN Document Server

    Javidi, Bahram; Son, Jung-Young

    2009-01-01

    Three-Dimensional Imaging, Visualization, and Display describes recent developments, as well as the prospects and challenges facing 3D imaging, visualization, and display systems and devices. With the rapid advances in electronics, hardware, and software, 3D imaging techniques can now be implemented with commercially available components and can be used for many applications. This volume discusses the state-of-the-art in 3D display and visualization technologies, including binocular, multi-view, holographic, and image reproduction and capture techniques. It also covers 3D optical systems, 3D display instruments, 3D imaging applications, and details several attractive methods for producing 3D moving pictures. This book integrates the background material with new advances and applications in the field, and the available online supplement will include full color videos of 3D display systems. Three-Dimensional Imaging, Visualization, and Display is suitable for electrical engineers, computer scientists, optical e...

  14. Arching in three-dimensional clogging

    Directory of Open Access Journals (Sweden)

    Török János

    2017-01-01

    Full Text Available Arching in dry granular material is a long established concept, however it remains still an open question how three-dimensional orifices clog. We investigate by means of numerical simulations and experimental data how the outflow creates a blocked configuration of particles. We define the concave surface of the clogged dome by two independent methods (geometric and density based. The average shape of the cupola for spheres is almost a hemisphere but individual samples have large holes in the structure indicating a blocked state composed of two-dimensional force chains rather than three-dimensional objects. The force chain structure justifies this assumption. For long particles the clogged configurations display large variations, and in certain cases the empty region reaches a height of 5 hole diameters. These structures involve vertical walls consisting of horizontally placed stable stacking of particles.

  15. Arching in three-dimensional clogging

    Science.gov (United States)

    Török, János; Lévay, Sára; Szabó, Balázs; Somfai, Ellák; Wegner, Sandra; Stannarius, Ralf; Börzsönyi, Tamás

    2017-06-01

    Arching in dry granular material is a long established concept, however it remains still an open question how three-dimensional orifices clog. We investigate by means of numerical simulations and experimental data how the outflow creates a blocked configuration of particles. We define the concave surface of the clogged dome by two independent methods (geometric and density based). The average shape of the cupola for spheres is almost a hemisphere but individual samples have large holes in the structure indicating a blocked state composed of two-dimensional force chains rather than three-dimensional objects. The force chain structure justifies this assumption. For long particles the clogged configurations display large variations, and in certain cases the empty region reaches a height of 5 hole diameters. These structures involve vertical walls consisting of horizontally placed stable stacking of particles.

  16. Data reading with the aid of one-photon and two-photon luminescence in three-dimensional optical memory devices based on photochromic materials

    International Nuclear Information System (INIS)

    Akimov, Denis A; Zheltikov, Aleksei M; Koroteev, Nikolai I; Naumov, A N; Fedotov, Andrei B; Magnitskiy, Sergey A; Sidorov-Biryukov, D A; Sokolyuk, N T

    1998-01-01

    The problem of nondestructive reading of the data stored in the interior of a photochromic sample was analysed. A comparison was made of the feasibility of reading based on one-photon and two-photon luminescence. A model was proposed for the processes of reading the data stored in photochromic molecules with the aid of one-photon and two-photon luminescence. In addition to photochromic transitions, account was taken of the transfer of populations between optically coupled transitions in molecules under the action of the exciting radiation. This model provided a satisfactory description of the kinetics of decay of the coloured form of bulk samples of spiropyran and made it possible to determine experimentally the quantum yield of the reverse photoreaction as well as the two-photon absorption cross section of the coloured form. Measurements were made of the characteristic erasure times of the data stored in a photochromic medium under one-photon and two-photon luminescence reading conditions. It was found that the use of two-photon luminescence made it possible to enhance considerably the contrast and localisation of the optical data reading scheme in three-dimensional optical memory devices. The experimental results were used to estimate the two-photon absorption cross section of the coloured form of a sample of indoline spiropyran in a polymethyl methacrylate matrix. (laser applications and other topics in quantum electronics)

  17. Three-Dimensional Reconstruction of Sandpile Interiors

    Science.gov (United States)

    Seidler, G. T.

    2001-03-01

    The granular bed, or sandpile, has become one of the condensed matter physicist's favorite systems. In addition to conceptual appeal, the simplest sandpile of monodisperse hard spheres is a valuable model system for understanding powders, liquids, and metallic glasses. Any fundamental approach to the transport and mechanical properties of three-dimensional mesoscale disordered materials must follow from a thorough understanding of their structure. However, in the overwhelming majority of cases, structure measurements have been limited to the mean filling fraction and the structural autocorrelation function. This is particularly unfortunate in the ongoing sandpile renaissance, where some of the most interesting questions concern structure and the relationship between structure and dynamics. I will discuss the combination of synchrotron x-ray microtomography and computer vision algorithms to perform three-dimensional virtual reconstructions of real sandpiles. This technique is rapid and noninvasive, and is applicable to samples large enough to separate bulk and boundary properties. The resulting complete knowledge of structure can be used to calculate otherwise inaccessible correlation functions. I will present results for several measures of the bond-orientational order in three-dimensional sandpiles, including fabric tensors and nematic order parameters.

  18. Real three-dimensional biquadrics

    Energy Technology Data Exchange (ETDEWEB)

    Krasnov, Vyacheslav A [P.G. Demidov Yaroslavl State University, Yaroslavl (Russian Federation)

    2010-09-07

    We find the topological types of biquadrics (complete intersections of two real four-dimensional quadrics). The rigid isotopy classes of real three-dimensional biquadrics were described long ago: there are nine such classes. We find the correspondence between the topological types of real biquadrics and their rigid isotopy classes, and show that only two rigid isotopy classes have the same topological type. One of these classes consists of real GM-varieties and the other contains no GM-varieties. We also study the sets of real lines on real biquadrics.

  19. PERFORMANCE ENHANCEMENT OF A MINIATURE STIRLING CRYOCOOLER WITH A MULTI MESH REGENERATOR DESIGN

    Directory of Open Access Journals (Sweden)

    KISHOR KUMAR V. V.

    2017-06-01

    Full Text Available A parametric study has been carried out using the software REGEN 3.3 to optimize the regenerator of a miniature Stirling cryocooler operating with a warm end temperature of 300 K and cold end temperature of 80 K. Regenerator designs which produce the maximum coefficient of performance (COP of the system is considered as an optimized regenerator. The length and diameter of the regenerator were fixed from the cooler system requirements. Single mesh regenerators made of 200, 250, 300, 400 and 450 Stainless Steel wire meshes were considered and the optimum phase angle and mesh size were obtained. A maximum COP of 0.1475 was obtained for 300 mesh regenerator at 70° phase angle. Then multi mesh regenerators were considered with finer mesh on the cold end and coarser mesh on the hot end. The optimum size and length of each mesh in the multi mesh regenerator and the optimum phase angle were calculated. The maximum COP of 0.156 was obtained for 200 300-400 multi mesh regenerator at 70° phase angle. The COP and net refrigeration obtained for an optimized multi mesh regenerator was found to be significantly higher than that of a single mesh regenerator. Thus a multi mesh regenerator design with a proper combination of regenerator mesh size and length can enhance the regenerator effectiveness.

  20. Three-dimensional activated graphene network-sulfonate-terminated polymer nanocomposite as a new electrode material for the sensitive determination of dopamine and heavy metal ions.

    Science.gov (United States)

    Yuan, Xiaoyan; Zhang, Yijia; Yang, Lu; Deng, Wenfang; Tan, Yueming; Ma, Ming; Xie, Qingji

    2015-03-07

    We report here that three-dimensional activated graphene networks (3DAGNs) are a better matrix to prepare graphene-polymer nanocomposites for sensitive electroanalysis than two-dimensional graphene nanosheets (2DGNs). 3DAGNs were synthesized in advance by the direct carbonization and simultaneous chemical activation of a cobalt ion-impregnated D113-type ion exchange resin, which showed an interconnected network structure and a large specific surface area. Then, the 3DAGN-sulfonate-terminated polymer (STP) nanocomposite was prepared via the in situ chemical co-polymerization of m-aminobenzene sulfonic acid and aniline in the presence of 3DAGNs. The 3DAGN-STP nanocomposite can adsorb dopamine (DA) and heavy metal ions, which was confirmed by quartz crystal microbalance studies. The 3DAGN-STP modified glassy carbon electrode (GCE) was used for the electrochemical detection of DA in the presence of ascorbic acid and uric acid, with a linear response range of 0.1-32 μM and a limit of detection of 10 nM. In addition, differential pulse voltammetry was used for the simultaneous determination of Cd(2+) and Pb(2+) at the 3DAGN-STP/GCE further modified with a bismuth film, exhibiting linear response ranges of 1-70 μg L(-1) for Cd(2+) and 1-80 μg L(-1) for Pb(2+) with limits of detection of 0.1 μg L(-1) for Cd(2+) and 0.2 μg L(-1) for Pb(2+). Because the 3DAGN-STP can integrate the advantages of 3DAGNs with STPs, the 3DAGN-STP/GCE was more sensitive than the bare GCE, 3DAGN/GCE, and 2DGN-STP/GCE for the determination of DA and heavy metal ions.

  1. Three dimensional periodic foundations for base seismic isolation

    International Nuclear Information System (INIS)

    Yan, Y; Mo, Y L; Cheng, Z; Shi, Z; Menq, F; Tang, Y

    2015-01-01

    Based on the concept of phononic crystals, periodic foundations made of periodic materials are investigated in this paper. The periodic foundations can provide low frequency band gaps, which cover the main frequency ranges of seismic waves. Therefore, the periodic foundations are able to protect the upper structures during earthquake events. In this paper, the basic theory of three dimensional periodic foundations is studied and the finite element method was used to conduct the sensitivity study. A simplified three-dimensional periodic foundation with a superstructure was tested in the field and the feasibility of three dimensional periodic foundations was proved. The test results showed that the response of the upper structure with the three dimensional periodic foundation was reduced under excitation waves with the main frequency falling in the attenuation zones. The finite element analysis results are consistent with the experimental data, indicating that three dimensional periodic foundations are a feasible way of reducing seismic vibrations. (paper)

  2. A multi-mesh finite element method for phase-field based photonic band structure optimization

    Science.gov (United States)

    Wu, Shengyang; Hu, Xianliang; Zhu, Shengfeng

    2018-03-01

    A novel finite element method with multiple meshes is proposed, which is applied to solve the phase-field models for photonic band structures optimization. In our approach, fine meshes are used for the phase field evolution, which allows fine resolution for shape representations. The coarse meshes are adopted for the finite element analysis of the state equation. Such a multi-mesh approach could save a considerable amount of computational costs. Numerical convergence is illustrated through comparisons between our computational results and benchmarks. The efficiency and robustness of the multi-mesh approach are also shown.

  3. Metalized, three-dimensional structured oxygen cathode materials for lithium/air batteries and method for making and using the same

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Weibing; Buettner-Garrett, Josh

    2017-04-18

    This disclosure relates generally to cathode materials for electrochemical energy cells, more particularly to metal/air electrochemical energy cell cathode materials containing silver vanadium oxide and methods of making and using the same. The metal/air electrochemical energy cell can be a lithium/air electrochemical energy cell. Moreover the silver vanadium oxide can be a catalyst for one or more of oxidation and reduction processes of the electrochemical energy cell.

  4. The three-dimensional microstructure of polycrystalline materials unravelled by synchrotron light; La microstructure 3D des materiaux polycristallins vue sous la lumiere synchrotron

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, W.; Herbig, M. [Universite de Lyon, INSA-Lyon, MATEIS, UMR 5510 CNRS, LyonTech Campus, Bat. Saint-Exupery, 25 avenue Jean Capelle, F-69621 Villeurbanne Cedex (France); Ludwig, W.; King, A; Reischig, P. [European Synchrotron Radiation Facility, 6 rue J. Horowitz, BP 220, F-38043 Grenoble (France); Marrow, J. [University of Oxford, Department of Materiels, Parks road, Oxford OX1 3PH (United Kingdom); Babout, L. [Computer Engineering Department, Technical University of Lodz, ul. Stefanowskiego 18/22, PL-90- 537 Lodz (Poland); Mejdal Lauridsen, E. [Materials Research Department, Riso National Laboratory for Sustainable Energy, Technical University of Denmark (DTU), Building 228, PO Box 49, DK-4000 Roskilde (Denmark); Proudhon, H. [MINES ParisTech, Centre des Materiaux, UMR 7633 CNRS, BP 87, F-91003 Evry Cedex (France)

    2011-07-01

    Synchrotron radiation X-ray imaging and diffraction techniques offer new possibilities for non-destructive bulk characterization of polycrystalline materials. Minute changes in electron density (different crystallographic phases, cracks, porosities) can be detected using 3D imaging modes exploiting Fresnel diffraction and the coherence properties of third generation synchrotron beams. X-ray diffraction contrast tomography, a technique based on Bragg diffraction imaging, provides access to the 3D shape, orientation and elastic strain state of the individual grains from polycrystalline sample volumes containing several hundred up to a few thousand grains. Combining both imaging modalities allows a comprehensive description of the microstructure of the material at the micrometer length scale. Repeated observations during (interrupted) mechanical tests provide unprecedented insight into crystallographic and grain microstructure related aspects of polycrystal deformation and degradation mechanisms in materials, fulfilling some conditions on grain size and deformation state. (authors)

  5. Three dimensional magnetic abacus memory.

    Science.gov (United States)

    Zhang, ShiLei; Zhang, JingYan; Baker, Alexander A; Wang, ShouGuo; Yu, GuangHua; Hesjedal, Thorsten

    2014-08-22

    Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately, the magnetic abacus adopts a new encoding scheme. It is inspired by the idea of second quantisation, dealing with the memory state of the entire stack simultaneously. Direct read operations are implemented by measuring the artificially engineered 'quantised' Hall voltage, each representing a count of the spin-up and spin-down layers in the stack. This new memory system further allows for both flexible scaling of the system and fast communication among cells. The magnetic abacus provides a promising approach for future nonvolatile 3D magnetic random access memory.

  6. Three-Dimensional Laser Microvision

    Science.gov (United States)

    Shimotahira, Hiroshi; Iizuka, Keigo; Chu, Sun-Chun; Wah, Christopher; Costen, Furnie; Yoshikuni, Yuzo

    2001-04-01

    A three-dimensional (3-D) optical imaging system offering high resolution in all three dimensions, requiring minimum manipulation and capable of real-time operation, is presented. The system derives its capabilities from use of the superstructure grating laser source in the implementation of a laser step frequency radar for depth information acquisition. A synthetic aperture radar technique was also used to further enhance its lateral resolution as well as extend the depth of focus. High-speed operation was made possible by a dual computer system consisting of a host and a remote microcomputer supported by a dual-channel Small Computer System Interface parallel data transfer system. The system is capable of operating near real time. The 3-D display of a tunneling diode, a microwave integrated circuit, and a see-through image taken by the system operating near real time are included. The depth resolution is 40 m; lateral resolution with a synthetic aperture approach is a fraction of a micrometer and that without it is approximately 10 m.

  7. Three dimensional magnetic abacus memory

    Science.gov (United States)

    Zhang, Shilei; Zhang, Jingyan; Baker, Alexander; Wang, Shouguo; Yu, Guanghua; Hesjedal, Thorsten

    2015-03-01

    Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the individual data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately, the magnetic abacus adopts a new encoding scheme which envisages a classical abacus with the beads operated by electron spins. It is inspired by the idea of second quantization, dealing with the memory state of the entire stack simultaneously. Direct read operations are implemented by measuring the artificially engineered `quantized' Hall voltage, representing a count of the spin-up and spin-down layers in the stack. This concept of `second quantization of memory' realizes the 3D memory architecture with superior reading and operation efficiency, thus is a promising approach for future nonvolatile magnetic random access memory.

  8. Evaluation by Medical Students of the Educational Value of Multi-Material and Multi-Colored Three-Dimensional Printed Models of the Upper Limb for Anatomical Education

    Science.gov (United States)

    Mogali, Sreenivasulu Reddy; Yeong, Wai Yee; Tan, Heang Kuan Joel; Tan, Gerald Jit Shen; Abrahams, Peter H.; Zary, Nabil; Low-Beer, Naomi; Ferenczi, Michael Alan

    2018-01-01

    For centuries, cadaveric material has been the cornerstone of anatomical education. For reasons of changes in curriculum emphasis, cost, availability, expertise, and ethical concerns, several medical schools have replaced wet cadaveric specimens with plastinated prosections, plastic models, imaging, and digital models. Discussions about the…

  9. Comparison of two three-dimensional cephalometric analysis computer software

    OpenAIRE

    Sawchuk, Dena; Alhadlaq, Adel; Alkhadra, Thamer; Carlyle, Terry D; Kusnoto, Budi; El-Bialy, Tarek

    2014-01-01

    Background: Three-dimensional cephalometric analyses are getting more attraction in orthodontics. The aim of this study was to compare two softwares to evaluate three-dimensional cephalometric analyses of orthodontic treatment outcomes. Materials and Methods: Twenty cone beam computed tomography images were obtained using i-CAT® imaging system from patient's records as part of their regular orthodontic records. The images were analyzed using InVivoDental5.0 (Anatomage Inc.) and 3DCeph™ (Unive...

  10. Three-dimensional finite element analysis of the stress distribution pattern in a mandibular first molar tooth restored with five different restorative materials

    Directory of Open Access Journals (Sweden)

    Kathleen Manuela D'souza

    2017-01-01

    Conclusions: ICZ crown displayed the highest peak von Mises stress values under maximum and masticatory bite forces. ICZ and Lava crowns also allowed the least amount of stress distribution to the surrounding tooth structure, which is indicative of a favorable response of the underlying tooth structure to the overlying full-coverage indirect restorative material. These results suggest that ICZ and Lava crowns can be recommended for clinical use in cases of badly damaged teeth.

  11. Measurement of fibre-fibre contact in three-dimensional images of fibrous materials obtained from X-ray synchrotron microtomography

    International Nuclear Information System (INIS)

    Malmberg, F.; Lindblad, J.; Ostlund, C.; Almgren, K.M.; Gamstedt, E.K.

    2011-01-01

    A series of wood-fibre mats was investigated using high-resolution phase-contrast microtomography at the beamline ID 19 of the European Synchrotron Radiation Facility in Grenoble, France. A method for data reduction to quantify the degree of fibre-fibre contact has been derived. The degree of fibre-fibre contact and bonding plays a fundamental role in the mechanical properties of cellulose-fibre mats, paper materials and cellulose-fibre composites. The proposed computerised automated method consists of two parts. First, fibre lumens are segmented using a watershed based method. This information is then used to identify fibre-fibre contacts in projections along the z-axis of the material. The method is tested on microtomographic images of mats made of wood pulp fibres, and is shown to successfully detect differences in the amount of fibre-fibre contact between samples. The degree of fibre-fibre contact correlates well with measured out-of-plane strength of the fibrous material.

  12. Three dimensional thrust chamber life prediction

    Science.gov (United States)

    Armstrong, W. H.; Brogren, E. W.

    1976-01-01

    A study was performed to analytically determine the cyclic thermomechanical behavior and fatigue life of three configurations of a Plug Nozzle Thrust Chamber. This thrust chamber is a test model which represents the current trend in nozzle design calling for high performance coupled with weight and volume limitations as well as extended life for reusability. The study involved the use of different materials and material combinations to evaluate their application to the problem of low-cycle fatigue in the thrust chamber. The thermal and structural analyses were carried out on a three-dimensional basis. Results are presented which show plots of continuous temperature histories and temperature distributions at selected times during the operating cycle of the thrust chamber. Computed structural data show critical regions for low-cycle fatigue and the histories of strain within the regions for each operation cycle.

  13. Ordered three-dimensional interconnected nanoarchitectures in anodic porous alumina

    Science.gov (United States)

    Martín, Jaime; Martín-González, Marisol; Fernández, Jose Francisco; Caballero-Calero, Olga

    2014-01-01

    Three-dimensional nanostructures combine properties of nanoscale materials with the advantages of being macro-sized pieces when the time comes to manipulate, measure their properties, or make a device. However, the amount of compounds with the ability to self-organize in ordered three-dimensional nanostructures is limited. Therefore, template-based fabrication strategies become the key approach towards three-dimensional nanostructures. Here we report the simple fabrication of a template based on anodic aluminum oxide, having a well-defined, ordered, tunable, homogeneous 3D nanotubular network in the sub 100 nm range. The three-dimensional templates are then employed to achieve three-dimensional, ordered nanowire-networks in Bi2Te3 and polystyrene. Lastly, we demonstrate the photonic crystal behavior of both the template and the polystyrene three-dimensional nanostructure. Our approach may establish the foundations for future high-throughput, cheap, photonic materials and devices made of simple commodity plastics, metals, and semiconductors. PMID:25342247

  14. Three-Dimensional Porous Si and SiO2 with In Situ Decorated Carbon Nanotubes As Anode Materials for Li-ion Batteries.

    Science.gov (United States)

    Su, Junming; Zhao, Jiayue; Li, Liangyu; Zhang, Congcong; Chen, Chunguang; Huang, Tao; Yu, Aishui

    2017-05-31

    A high-capacity Si anode is always accompanied by very large volume expansion and structural collapse during the lithium-ion insertion/extraction process. To stabilize the structure of the Si anode, magnesium vapor thermal reduction has been used to synthesize porous Si and SiO 2 (pSS) particles, followed by in situ growth of carbon nanotubes (CNTs) in pSS pores through a chemical vapor deposition (CVD) process. Field-emission scanning electron microscopy and high-resolution transmission electron microscopy have shown that the final product (pSS/CNTs) possesses adequate void space intertwined by uniformly distributed CNTs and inactive silica in particle form. pSS/CNTs with such an elaborate structural design deliver improved electrochemical performance, with better coulombic efficiency (70% at the first cycle), cycling capability (1200 mAh g -1 at 0.5 A g -1 after 200 cycles), and rate capability (1984, 1654, 1385, 1072, and 800 mAh g -1 at current densities of 0.1, 0.2, 0.5, 1, and 2 A g -1 , respectively), compared to pSS and porous Si/CNTs. These merits of pSS/CNTs are attributed to the capability of void space to absorb the volume changes and that of the silica to confine the excessive lithiation expansion of the Si anode. In addition, CNTs have interwound the particles, leading to significant enhancement of electronic conductivity before and after Si-anode pulverization. This simple and scalable strategy makes it easy to expand the application to manufacturing other alloy anode materials.

  15. Three-dimensional detectors for neutron imaging

    Science.gov (United States)

    Mendicino, R.; Dalla Betta, G.-F.

    2018-01-01

    Solid-state sensors fabricated with 3D technologies and coupled to different neutron converter materials have been developed by several groups as direct replacement of 3 He gas detectors, mainly for homeland security applications. Results so far achieved in terms of detection efficiency are quite good (up to ≃50%) and, combined with the intrinsic excellent position resolution of silicon sensors, could lead to high performance neutron imaging systems. In this paper, we review the state of the art in three-dimensional silicon sensors for thermal-neutron detection, addressing the most promising solutions for neutron imaging. Moreover, selected results from the developments at the University of Trento on 3D pixelated detectors having relatively low fabrication complexity and expected high neutron detection efficiency up to 30% will be reported.

  16. Shape memory polymers: three-dimensional isotropic modeling

    Science.gov (United States)

    Balogun, Olaniyi; Mo, Changki

    2014-04-01

    This paper presents a comprehensive three-dimensional isotropic numerical simulation for a thermo-mechanical constitutive model of shape memory polymers (SMPs). In order to predict the thermo-mechanical behavior of SMPs, a one-dimensional rheological thermo-mechanical constitutive model is adopted, translated into a three-dimensional form and a time discrete form of the three-dimensional model is then presented. Numerical simulation of this model was developed using the UMAT subroutine capabilities of the finite element software ABAQUS. Evolution of the analysis was conducted by making use of the backward difference scheme, which was applied to all quantities within the model, including the material properties. A comparison of the numerical simulation results was carried out with the available experimental data. Numerical simulation results clearly exhibit the thermo-mechanical properties of the material which include shape fixity, shape recovery, and recovery stress. Finally, a prediction for the transverse and shear directions of the material is presented.

  17. Electron tomography, three-dimensional Fourier analysis and colour prediction of a three-dimensional amorphous biophotonic nanostructure

    Science.gov (United States)

    Shawkey, Matthew D.; Saranathan, Vinodkumar; Pálsdóttir, Hildur; Crum, John; Ellisman, Mark H.; Auer, Manfred; Prum, Richard O.

    2009-01-01

    Organismal colour can be created by selective absorption of light by pigments or light scattering by photonic nanostructures. Photonic nanostructures may vary in refractive index over one, two or three dimensions and may be periodic over large spatial scales or amorphous with short-range order. Theoretical optical analysis of three-dimensional amorphous nanostructures has been challenging because these structures are difficult to describe accurately from conventional two-dimensional electron microscopy alone. Intermediate voltage electron microscopy (IVEM) with tomographic reconstruction adds three-dimensional data by using a high-power electron beam to penetrate and image sections of material sufficiently thick to contain a significant portion of the structure. Here, we use IVEM tomography to characterize a non-iridescent, three-dimensional biophotonic nanostructure: the spongy medullary layer from eastern bluebird Sialia sialis feather barbs. Tomography and three-dimensional Fourier analysis reveal that it is an amorphous, interconnected bicontinuous matrix that is appropriately ordered at local spatial scales in all three dimensions to coherently scatter light. The predicted reflectance spectra from the three-dimensional Fourier analysis are more precise than those predicted by previous two-dimensional Fourier analysis of transmission electron microscopy sections. These results highlight the usefulness, and obstacles, of tomography in the description and analysis of three-dimensional photonic structures. PMID:19158016

  18. Elastocapillary fabrication of three-dimensional microstructures

    NARCIS (Netherlands)

    van Honschoten, J.W.; Berenschot, Johan W.; Ondarcuhu, T.; Sanders, Remco G.P.; Sundaram, J.; Elwenspoek, Michael Curt; Tas, Niels Roelof

    2010-01-01

    We describe the fabrication of three-dimensional microstructures by means of capillary forces. Using an origami-like technique, planar silicon nitride structures of various geometries are folded to produce three-dimensional objects of 50–100 m. Capillarity is a particularly effective mechanism since

  19. Mesostructured Metal Germanium Sulfide and Selenide Materials Based on the Tetrahedral [Ge 4S 10] 4- and [Ge 4Se 10] 4- Units: Surfactant Templated Three-Dimensional Disordered Frameworks Perforated with Worm Holes

    Science.gov (United States)

    Wachhold, Michael; Kasthuri Rangan, K.; Lei, Ming; Thorpe, M. F.; Billinge, Simon J. L.; Petkov, Valeri; Heising, Joy; Kanatzidis, Mercouri G.

    2000-06-01

    The polymerization of [Ge4S10]4- and [Ge4Se10]4- unit clusters with the divalent metal ions Zn2+, Cd2+, Hg2+, Ni2+, and Co2+ in the presence of various surfactant cations leads to novel mesostructured phases. The surfactants are the quaternary ammonium salts C12H25NMe3Br, C14H29NMe3Br, C16H33NMe3Br, and C18H37NMe3Br, which play the role of templates, helping to assemble a three-dimensional mesostructured metal-germanium chalcogenide framework. These materials are stoichiometric in nature and have the formula of (R-NMe3)2[MGe4Q10] (Q=S, Se). The local atomic structure was probed by X-ray diffuse scattering and pair distribution function analysis methods and indicates that the adamantane clusters stay intact while the linking metal atoms possess a tetrahedral coordination environment. A model can be derived, from the comparison of measured and simulated X-ray powder diffraction patterns, describing the structure as an amorphous three-dimensional framework consisting of adamantane [Ge4Q10]4- units that are bridged by tetrahedral coordinated M2+ cations. The network structures used in the simulations were derived from corresponding disordered structures developed for amorphous silicon. The frameworks in (R-NMe3)2[MGe4Q10] are perforated with worm hole-like tunnels, occupied by the surfactant cations, which show no long-range order. This motif is supported by transmission electron microscopy images of these materials. The pore sizes of these channels were estimated to lie in the range of 20-30 Å, depending on the appointed surfactant cation length. The framework wall thickness of ca. 10 Å is thereby independent from the surfactant molecules used. Up to 80% of the surfactant molecules can be removed by thermal degradation under vacuum without loss of mesostructural integrity. Physical, chemical, and spectroscopic properties of these materials are discussed.

  20. Primary and Secondary Three Dimensional Microbatteries

    Science.gov (United States)

    Cirigliano, Nicolas

    Today's MEMS devices are limited more so by the batteries that supply their power than the fabrication methods used to build them. Thick battery electrodes are capable of providing adequate energy, but long and tortuous diffusion pathways lead to low power capabilities. On the other hand, thin film batteries can operate at significant current densities but require large surface areas to supply practical energy. This dilemma can be solved by either developing new high capacity materials or by engineering new battery designs that decouple power and energy. Three dimensional batteries redesign traditional configurations to create nonplanar interfaces between battery components. This can be done by introducing hierarchical structures into the electrode shape. Designs such as these provide a maximum surface area over which chemical reactions can occur. Furthermore, by maintaining small feature sizes, ion diffusion and electronic transport distances can remain minimal. Manipulating these properties ensures fast kinetics that are required for high power situations. Energy density is maximized by layering material in the vertical direction, thus ensuring a minimal footprint area. Three dimensional carbon electrodes are fabricated using basic MEMS techniques. A silicon mold is anisotropically etched to produce channels of a predetermined diameter. The channels are then filled using an infiltration technique with electrode slurry. Once dried, the mold is attached to a current collector and etched using a XeF2 process. Electrodes of varying feature sizes have been fabricated using this method with aspect ratios ranging from 3.5:1 to 7:1. 3D carbon electrodes are shown to obtain capacities over 8 mAh/cm2 at 0.1 mA/cm2, or nearly 700% higher than planar carbon electrodes. When assembled with a planar cathode, the battery cell produced an average discharge capacity of 40 J/cm 2 at a current density of 0.2 mA/cm2. This places the energy density values slightly less than thick

  1. Microlaser-based three-dimensional display

    Science.gov (United States)

    Takeuchi, Eric B.; Bergstedt, Robert; Hargis, David E.; Higley, Paul D.

    1999-08-01

    Three dimensional (3D) displays are critical for viewing complex multi-dimensional information and for viewing representations of the three dimensional real world. A teaming arrangement between Laser Power Corporation (LPC) and Specialty Devices, Inc. (SDI) has led to the feasibility demonstration of a directly-viewed three dimensional volumetric display. LPC has developed red, green, and blue (RGB) diode pumped solid state microlaser display technology for use as a high resolution, high brightness display engine for the three dimensional display. Concurrently, SDI has developed a unique technology for viewing high resolution three dimensional volumetric images without external viewing aids (eye wear). When coupled to LPC's display engine, the resultant all solid state three dimensional display presets a true, physical three dimensionality which is directly viewable from all angles by multiple viewers without additional viewing equipment (eye wear). The resultant volumetric display will further enable applications such as the 'virtual sandbox,' visualization of radar and sonar data, air traffic control, remote surgery and diagnostics, and CAD workstations.

  2. Three dimensional characterization and archiving system

    International Nuclear Information System (INIS)

    Sebastian, R.L.; Clark, R.; Gallman, P.

    1996-01-01

    The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D and D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D and D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. The 3D-ICAS system robotically conveys a multisensor probe near the surfaces to be inspected. The sensor position and orientation are monitored and controlled using coherent laser radar (CLR) tracking. The CLR also provides 3D facility maps which establish a 3D world view within which the robotic sensor system can operate

  3. Three dimensional characterization and archiving system

    International Nuclear Information System (INIS)

    Sebastian, R.L.; Clark, R.; Gallman, P.

    1995-01-01

    The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D ampersand D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D ampersand D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. Chemical analysis plays a vital role throughout the process of decontamination. Before clean-up operations can begin the site must be characterized with respect to the type and concentration of contaminants, and detailed site mapping must clarify areas of both high and low risk. During remediation activities chemical analysis provides a means to measure progress and to adjust clean-up strategy. Once the clean-up process has been completed the results of chemical analysis will verify that the site is in compliance with federal and local regulations

  4. Three dimensional characterization and archiving system

    Energy Technology Data Exchange (ETDEWEB)

    Sebastian, R.L.; Clark, R.; Gallman, P. [and others

    1995-12-01

    The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D&D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D&D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. Chemical analysis plays a vital role throughout the process of decontamination. Before clean-up operations can begin the site must be characterized with respect to the type and concentration of contaminants, and detailed site mapping must clarify areas of both high and low risk. During remediation activities chemical analysis provides a means to measure progress and to adjust clean-up strategy. Once the clean-up process has been completed the results of chemical analysis will verify that the site is in compliance with federal and local regulations.

  5. Three-Dimensional Printed Graphene Foams.

    Science.gov (United States)

    Sha, Junwei; Li, Yilun; Villegas Salvatierra, Rodrigo; Wang, Tuo; Dong, Pei; Ji, Yongsung; Lee, Seoung-Ki; Zhang, Chenhao; Zhang, Jibo; Smith, Robert H; Ajayan, Pulickel M; Lou, Jun; Zhao, Naiqin; Tour, James M

    2017-07-25

    An automated metal powder three-dimensional (3D) printing method for in situ synthesis of free-standing 3D graphene foams (GFs) was successfully modeled by manually placing a mixture of Ni and sucrose onto a platform and then using a commercial CO 2 laser to convert the Ni/sucrose mixture into 3D GFs. The sucrose acted as the solid carbon source for graphene, and the sintered Ni metal acted as the catalyst and template for graphene growth. This simple and efficient method combines powder metallurgy templating with 3D printing techniques and enables direct in situ 3D printing of GFs with no high-temperature furnace or lengthy growth process required. The 3D printed GFs show high-porosity (∼99.3%), low-density (∼0.015g cm -3 ), high-quality, and multilayered graphene features. The GFs have an electrical conductivity of ∼8.7 S cm -1 , a remarkable storage modulus of ∼11 kPa, and a high damping capacity of ∼0.06. These excellent physical properties of 3D printed GFs indicate potential applications in fields requiring rapid design and manufacturing of 3D carbon materials, for example, energy storage devices, damping materials, and sound absorption.

  6. Three-dimensional simulations of resistance spot welding

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Zhang, Wenqi; Perret, William

    2014-01-01

    This paper draws from the fundamentals of electro-thermo-mechanical coupling to the main aspects of finite element implementation and three-dimensional modelling of resistance welding. A new simulation environment is proposed in order to perform three-dimensional simulations and optimization of r....... The overall presentation is supported by numerical simulations of electrode misalignment caused by the flexibility of the welding machine arms and electrical shunting due to consecutive welds in the resistance spot welding of two sheets.......This paper draws from the fundamentals of electro-thermo-mechanical coupling to the main aspects of finite element implementation and three-dimensional modelling of resistance welding. A new simulation environment is proposed in order to perform three-dimensional simulations and optimization...... of resistance welding together with the simulations of conventional and special-purpose quasi-static mechanical tests. Three-dimensional simulations of resistance welding consider the electrical, thermal, mechanical and metallurgical characteristics of the material as well as the operating conditions...

  7. Novel multipole Wien filter as three-dimensional spin manipulator

    Science.gov (United States)

    Yasue, T.; Suzuki, M.; Tsuno, K.; Goto, S.; Arai, Y.; Koshikawa, T.

    2014-04-01

    Spin polarized electron beam is often used in material characterizations which relates to magnetism as well as in the high energy particle physics. The manipulation of the spin polarization toward the arbitrary direction is indispensable in such studies. In the present work, a novel multipole Wien filter is proposed as the three-dimensional spin manipulator, and a prototype 8-pole Wien filter is developed. It is applied to spin polarized low energy electron microscopy, and the variation of the magnetic contrast with managing the spin polarization is evaluated. It is confirmed that the novel multipole Wien filter can manipulate the spin polarization three-dimensionally.

  8. Novel multipole Wien filter as three-dimensional spin manipulator

    Energy Technology Data Exchange (ETDEWEB)

    Yasue, T., E-mail: yasue@isc.osakac.ac.jp; Suzuki, M.; Koshikawa, T. [Fundamental Electronics Research Institute, Osaka Electro-Communication University, 18-8 Hatsu-cho, Neyagawa, Osaka 572-8530 (Japan); Tsuno, K. [Electron Optics Solutions Tsuno, 10-11 Mihori, Akishima, Tokyo 196-0001 (Japan); Goto, S. [Sanyu Electron Co., Ltd., 1-22-6 Hyakunin-cho, Shinjyuku, Tokyo 169-0073 (Japan); Arai, Y. [Terabase Inc., Myodaiji, Okazaki, Aichi 444-8787 (Japan)

    2014-04-15

    Spin polarized electron beam is often used in material characterizations which relates to magnetism as well as in the high energy particle physics. The manipulation of the spin polarization toward the arbitrary direction is indispensable in such studies. In the present work, a novel multipole Wien filter is proposed as the three-dimensional spin manipulator, and a prototype 8-pole Wien filter is developed. It is applied to spin polarized low energy electron microscopy, and the variation of the magnetic contrast with managing the spin polarization is evaluated. It is confirmed that the novel multipole Wien filter can manipulate the spin polarization three-dimensionally.

  9. Three-dimensional boron particle loaded thermal neutron detector

    Science.gov (United States)

    Nikolic, Rebecca J.; Conway, Adam M.; Graff, Robert T.; Kuntz, Joshua D.; Reinhardt, Catherine; Voss, Lars F.; Cheung, Chin Li; Heineck, Daniel

    2014-09-09

    Three-dimensional boron particle loaded thermal neutron detectors utilize neutron sensitive conversion materials in the form of nano-powders and micro-sized particles, as opposed to thin films, suspensions, paraffin, etc. More specifically, methods to infiltrate, intersperse and embed the neutron nano-powders to form two-dimensional and/or three-dimensional charge sensitive platforms are specified. The use of nano-powders enables conformal contact with the entire charge-collecting structure regardless of its shape or configuration.

  10. Weyl and Dirac semimetals in three-dimensional solids

    Science.gov (United States)

    Armitage, N. P.; Mele, E. J.; Vishwanath, Ashvin

    2018-01-01

    Weyl and Dirac semimetals are three-dimensional phases of matter with gapless electronic excitations that are protected by topology and symmetry. As three-dimensional analogs of graphene, they have generated much recent interest. Deep connections exist with particle physics models of relativistic chiral fermions, and, despite their gaplessness, to solid-state topological and Chern insulators. Their characteristic electronic properties lead to protected surface states and novel responses to applied electric and magnetic fields. The theoretical foundations of these phases, their proposed realizations in solid-state systems, and recent experiments on candidate materials as well as their relation to other states of matter are reviewed.

  11. Parallelization method for three dimensional MOC calculation

    International Nuclear Information System (INIS)

    Zhang Zhizhu; Li Qing; Wang Kan

    2013-01-01

    A parallelization method based on angular decomposition for the three dimensional MOC was designed. To improve the parallel efficiency, the directions were pre-grouped and the groups were assembled to minimize the communication. The improved parallelization method was applied to the three dimensional MOC code TCM. The numerical results show that the calculation results of parallelization method are agreed with serial calculation results. The parallel efficiency gets obvious increase after the communication optimized and load balance. (authors)

  12. Three-dimensional effects in fracture mechanics

    International Nuclear Information System (INIS)

    Benitez, F.G.

    1991-01-01

    An overall view of the pioneering theories and works, which enlighten the three-dimensional nature of fracture mechanics during the last years is given. the main aim is not an exhaustive reviewing but the displaying of the last developments on this scientific field in a natural way. This work attempts to envisage the limits of disregarding the three-dimensional behaviour in theories, analyses and experiments. Moreover, it tries to draw attention on the scant fervour, although increasing, this three-dimensional nature of fracture has among the scientific community. Finally, a constructive discussion is presented on the use of two-dimensional solutions in the analysis of geometries which bear a three-dimensional configuration. the static two-dimensional solutions and its applications fields are reviewed. also, the static three-dimensional solutions, wherein a comparative analysis with elastoplastic and elastostatic solutions are presented. to end up, the dynamic three-dimensional solutions are compared to the asymptotic two-dimensional ones under the practical applications point of view. (author)

  13. [The application progress of three-dimensional cell culture technology in ophthalmology].

    Science.gov (United States)

    Zhao, Yun; Zhang, Lei; Zhao, Hong

    2015-11-01

    Three-dimensional cell culture technology is a kind of technology that cultures the cells in a three-dimensional cultivation by using a kind of scaffold materials in vitro. Its advantage is that the vivo microenvironment simulating degrees of the three-dimensional culture technology is higher than that of the two-dimensional planar cell culture model, and the controllability is also higher than the animal experiment. In recent years, with the development of tissue engineering technology, a varietiy of the stent of biological materials also a fast development, which provided a favorable platform for three-dimensional cell culture technology. In ophthalmology, three-dimensional cell culture has been applied to the cornea, retina and the visual system development and other optic tumor researches. The objective of this paper is to making a review the application status of the three-dimensional cell culture technology in the basic research and clinical treatment in ophthalmology.

  14. Development of three dimensional solid modeler

    International Nuclear Information System (INIS)

    Zahoor, R.M.A.

    1999-01-01

    The work presented in this thesis is aimed at developing a three dimensional solid modeler employing computer graphics techniques using C-Language. Primitives have been generated, by combination of plane surfaces, for various basic geometrical shapes including cylinder, cube and cone. Back face removal technique for hidden surface removal has also been incorporated. Various transformation techniques such as scaling, translation, and rotation have been included for the object animation. Three dimensional solid modeler has been created by the union of two primitives to demonstrate the capabilities of the developed program. (author)

  15. Three-dimensional imaging utilizing energy discrimination

    International Nuclear Information System (INIS)

    Gunter, D.L.; Hoffman, K.R.; Beck, R.N.

    1990-01-01

    An algorithm is proposed for three-dimensional image reconstruction in nuclear medicine which uses scattered radiation rather than multiple projected images to determine the source depth within the body. Images taken from numerous energy windows are combined to construct the source distribution in the body. The gamma-ray camera is not moved during the imaging process. Experiments with both Tc-99m and Ga-67 demonstrate that two channels of depth information can be extracted from the low energy images produced by scattered radiation. By combining this technique with standard SPECT reconstruction using multiple projections the authors anticipate much improved spatial resolution in the overall three-dimensional reconstruction

  16. Imaging unsteady three-dimensional transport phenomena

    Indian Academy of Sciences (India)

    2014-01-05

    Jan 5, 2014 ... The image data can be jointly analysed with the physical laws governing transport and principles of image formation. Hence, with the experiment suitably carried out, three-dimensional physical domains with unsteady processes can be accommodated. Optical methods promise to breach the holy grail of ...

  17. Three-Dimensional Printing Surgical Applications.

    Science.gov (United States)

    AlAli, Ahmad B; Griffin, Michelle F; Butler, Peter E

    2015-01-01

    Three-dimensional printing, a technology used for decades in the industrial field, gains a lot of attention in the medical field for its potential benefits. With advancement of desktop printers, this technology is accessible and a lot of research is going on in the medical field. To evaluate its application in surgical field, which may include but not limited to surgical planning, surgical education, implants, and prosthesis, which are the focus of this review. Research was conducted by searching PubMed, Web of science, and other reliable sources. We included original articles and excluded articles based on animals, those more than 10 years old, and those not in English. These articles were evaluated, and relevant studies were included in this review. Three-dimensional printing shows a potential benefit in surgical application. Printed implants were used in patient in a few cases and show successful results; however, longer follow-up and more trials are needed. Surgical and medical education is believed to be more efficient with this technology than the current practice. Printed surgical instrument and surgical planning are also believed to improve with three-dimensional printing. Three-dimensional printing can be a very powerful tool in the near future, which can aid the medical field that is facing a lot of challenges and obstacles. However, despite the reported results, further research on larger samples and analytical measurements should be conducted to ensure this technology's impact on the practice.

  18. Imaging unsteady three-dimensional transport phenomena

    Indian Academy of Sciences (India)

    2014-01-05

    Jan 5, 2014 ... physical domains with unsteady processes can be accommodated. Optical methods promise to breach the holy grail of measurements by extracting unsteady three-dimensional data in applications related to transport phenomena. Keywords. Optical measurement; fluid flow and transport; refractive index ...

  19. Three-dimensional chiral photonic superlattices.

    Science.gov (United States)

    Thiel, M; Fischer, H; von Freymann, G; Wegener, M

    2010-01-15

    We investigate three-dimensional photonic superlattices composed of polymeric helices in various spatial checkerboard-like arrangements. Depending on the relative phase shift and handedness of the chiral building blocks, different circular-dichroism resonances appear or are suppressed. Samples corresponding to four different configurations are fabricated by direct laser writing. The measured optical transmittance spectra are in good agreement with numerical calculations.

  20. Three dimensional electrochemical system for neurobiological studies

    DEFF Research Database (Denmark)

    Vazquez, Patricia; Dimaki, Maria; Svendsen, Winnie Edith

    2009-01-01

    In this work we report a novel three dimensional electrode array for electrochemical measurements in neuronal studies. The main advantage of working with these out-of-plane structures is the enhanced sensitivity of the system in terms of measuring electrochemical changes in the environment...

  1. Electron crystallography of three dimensional protein crystals

    NARCIS (Netherlands)

    Georgieva, Dilyana

    2008-01-01

    This thesis describes an investigation of the potential of electron diffraction for studying three dimensional sub-micro-crystals of proteins and pharmaceuticals. A prerequisite for using electron diffraction for structural studies is the predictable availability of tiny crystals. A method for

  2. Three-dimensional patterning methods and related devices

    Energy Technology Data Exchange (ETDEWEB)

    Putnam, Morgan C.; Kelzenberg, Michael D.; Atwater, Harry A.; Boettcher, Shannon W.; Lewis, Nathan S.; Spurgeon, Joshua M.; Turner-Evans, Daniel B.; Warren, Emily L.

    2016-12-27

    Three-dimensional patterning methods of a three-dimensional microstructure, such as a semiconductor wire array, are described, in conjunction with etching and/or deposition steps to pattern the three-dimensional microstructure.

  3. The thermoelectric performance of bulk three-dimensional graphene

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhi, E-mail: yangzhi@tyut.edu.cn [Key Lab of Advanced Transducers and Intelligent Control System, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024 (China); College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024 (China); Lan, Guoqiang; Ouyang, Bin [Department of Mining and Materials Engineering, McGill University, Montreal H3A 0C5 (Canada); Xu, Li-Chun; Liu, Ruiping [College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024 (China); Liu, Xuguang, E-mail: liuxuguang@tyut.edu.cn [Key Lab of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China); College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Song, Jun [Department of Mining and Materials Engineering, McGill University, Montreal H3A 0C5 (Canada)

    2016-11-01

    The electronic and thermoelectric properties of a new carbon bulk material, three-dimensional (3D) graphene, are investigated in this study. Our results show that 3D graphene has unique electronic structure, i.e., near the Fermi level there exist Dirac cones. More importantly, the thermoelectric performance of 3D graphene is excellent, at room temperature the thermoelectric figure of merit (ZT) is 0.21, an order of magnitude higher than that of graphene. By introducing line defects, the ZT of 3D graphene could be enhanced to 1.52, indicating 3D graphene is a powerful candidate for constructing novel thermoelectric materials. - Highlights: • There exist Dirac cones in three-dimensional (3D) graphene. • The thermoelectric performance of 3D graphene is excellent. • The defective 3D graphene has better thermoelectric performance.

  4. Three Dimensional Polarimetric Neutron Tomography of Magnetic Fields

    DEFF Research Database (Denmark)

    Sales, Morten; Strobl, Markus; Shinohara, Takenao

    2018-01-01

    -destructively with the potential to probe the interior of bulk samples which is not amenable otherwise. Using a pioneering polarimetric set-up for ToF neutron instrumentation in combination with a newly developed tailored reconstruction algorithm, the magnetic field generated by a current carrying solenoid has been measured......Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the first time successfully demonstrated a technique capable of measuring and reconstructing three dimensional magnetic field strengths and directions unobtrusively and non...... and reconstructed, thereby providing the proof-of-principle of a technique able to reveal hitherto unobtainable information on the magnetic fields in the bulk of materials and devices, due to a high degree of penetration into many materials, including metals, and the sensitivity of neutron polarisation to magnetic...

  5. Proton beam writing of three-dimensional microcavities

    International Nuclear Information System (INIS)

    Vanga, S.K.; Bettiol, A.A.

    2013-01-01

    Optical micro cavities exhibit high quality factors due to the circulation of resonant optical fields within the cavity. Polymers are good materials for the fabrication of micro cavities for practical applications due to the availability of various refractive indices and their low cost. Polymer micro cavities generally yield low Q-factors compared to semiconductor materials because of inherent material absorption losses, and their Q-factors are limited by the low index contrast between the polymer and the substrate material. In the present work, three dimensional micro cavities were fabricated in SU-8 using proton beam writing to enhance the index contrast by isolating the cavities from the substrate

  6. [Precision of three-dimensional printed brackets].

    Science.gov (United States)

    Zhang, D; Wang, L C; Zhou, Y H; Liu, X M; Li, J

    2017-08-18

    This study was based on digital orthodontic diagnosis work flow for indirect bonding transfer tray model design and three-dimensional (3D) printing, and the aim of this paper was to inspect the dimensional accuracyof 3D printed brackets, which is the foundation of the follow up work and hoped that will illuminate the clinical application of the digital orthodontics work flow. The samples which consisted of 14 cases of patients with malocclusion from Department of Orthodontics Peking University were selected, including 8 cases with tooth extraction and 6 cases without tooth extraction. All the 14 patients were taken intra-oral scan (Trios 3Shape, Denmark) and cone-beam computed tomography (CBCT, NewTom 3G volumetric scanner, Aperio Service,Italy)shooting after periodontal treatment. STL data and DICOM data were obtained from intraoral scans and CBCT images.Data segmentation, registration, fusion, automatic tooth arrangement, virtual positioning of orthodontic appliance and conversion the coordinates of malocclusion model were all done with self-programming software. The data of 3D printing model with brackets on it were output finally and printed out with EDEN260V (Objet Geometries, Israel) to make indirect bonding transfer tray. Digital vernier caliper was used to measure the length and width of upper and lower left brackets and buccal tubes on those 3D models after removal of surrounding supporting material by ultrasonic vibration and water-spray. Intra-examiner reliability was assessed by using intra-class correlation coefficients (ICC), and one-sample T test was used to compare the measurements with the standard dimensional data of the brackets. There were significant differences which range in 0.04-0.17 mm between the 13 items out of the 19 measurement items. Except for the length of the lower left premolars'brackets, mean values of the other items were greater than the test value. Although the measurement results in the width of brackets and the width and

  7. Solving implicit multi-mesh flow and conjugate heat transfer problems with RELAP-7

    International Nuclear Information System (INIS)

    Zou, L.; Peterson, J.; Zhao, H.; Zhang, H.; Andrs, D.; Martineau, R.

    2013-01-01

    The fully implicit simulation capability of RELAP-7 to solve multi-mesh flow and conjugate heat transfer problems for reactor system safety analysis is presented. Compared to general single-mesh simulations, the reactor system safety analysis-type of code has unique challenges due to its highly simplified, interconnected, one-dimensional, and zero-dimensional flow network describing multiple physics with significantly different time and length scales. To use the Jacobian-free Newton Krylov-type of solver, preconditioning is generally required for the Krylov method. The uniqueness of the reactor safety analysis-type of code in treating the interconnected flow network and conjugate heat transfer also introduces challenges in providing preconditioning matrix. Typical flow and conjugate heat transfer problems involved in reactor safety analysis using RELAP-7, as well as the special treatment on the preconditioning matrix are presented in detail. (authors)

  8. Three-dimensional imaging modalities in endodontics

    International Nuclear Information System (INIS)

    Mao, Teresa; Neelakantan, Prasanna

    2014-01-01

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome

  9. Three dimensional digital imaging of environmental data

    International Nuclear Information System (INIS)

    Nichols, R.L.; Eddy, C.A.

    1991-01-01

    The Environmental Sciences Section (ESS) of the Savannah River Laboratory has recently acquired the computer hardware (Silicon Graphics Personal Iris Workstations) and software (Dynamic Graphics, Interactive Surface and Volume Modeling) to perform three dimensional analysis of hydrogeologic data. Three dimensional digital imaging of environmental data is a powerful technique that can be used to incorporate field, analytical, and modeling results from geologic, hydrologic, ecologic, and chemical studies into a comprehensive model for visualization and interpretation. This report covers the contamination of four different sites of the Savannah River Plant. Each section of this report has a computer graphic display of the concentration of contamination in the groundwater and/or sediments of each site

  10. Three dimensional contact/impact methodology

    International Nuclear Information System (INIS)

    Kulak, R.F.

    1987-01-01

    The simulation of three-dimensional interface mechanics between reactor components and structures during static contact or dynamic impact is necessary to realistically evaluate their structural integrity to off-normal loads. In our studies of postulated core energy release events, we have found that significant structure-structure interactions occur in some reactor vessel head closure designs and that fluid-structure interactions occur within the reactor vessel. Other examples in which three-dimensional interface mechanics play an important role are: (1) impact response of shipping casks containing spent fuel, (2) whipping pipe impact on reinforced concrete panels or pipe-to-pipe impact after a pipe break, (3) aircraft crash on secondary containment structures, (4) missiles generated by turbine failures or tornados, and (5) drops of heavy components due to lifting accidents. The above is a partial list of reactor safety problems that require adequate treatment of interface mechanics and are discussed in this paper

  11. THREE DIMENSIONAL GRAPHICAL REPRESENTATION OF QUALITY

    Directory of Open Access Journals (Sweden)

    Vineet V. Kumar

    2014-03-01

    Full Text Available Quality is an important aspect for every firm in modern era of competition. Every product has tough competition in terms of market reach. The factor, which actually makes any product long run in market, is quality and hence quality is the stepping-stone for success of any firm. For everyone meaning of quality is different. We have seen several economists who have defined quality by considering different factors, but what all of them have common in them is Customer satisfaction. Customer satisfaction is the ultimate result of quality. In three-dimensional graphical representation of quality, optimum quality is obtained by using three-dimensional graph by considering some important factors governing quality of any product, limiting factor, and customer satisfaction.

  12. Three-dimensional imaging modalities in endodontics

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Teresa; Neelakantan, Prasanna [Dept. of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Saveetha University, Chennai (India)

    2014-09-15

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.

  13. Three-dimensional imaging modalities in endodontics

    Science.gov (United States)

    Mao, Teresa

    2014-01-01

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome. PMID:25279337

  14. Geometric actions for three-dimensional gravity

    Science.gov (United States)

    Barnich, G.; González, H. A.; Salgado-Rebolledo, P.

    2018-01-01

    The solution space of three-dimensional asymptotically anti-de Sitter or flat Einstein gravity is given by the coadjoint representation of two copies of the Virasoro group in the former and the centrally extended BMS3 group in the latter case. Dynamical actions that control these solution spaces are usually constructed by starting from the Chern–Simons formulation and imposing all boundary conditions. In this note, an alternative route is followed. We study in detail how to derive these actions from a group-theoretical viewpoint by constructing geometric actions for each of the coadjoint orbits, including the appropriate Hamiltonians. We briefly sketch relevant generalizations and potential applications beyond three-dimensional gravity.

  15. SNAP - a three dimensional neutron diffusion code

    International Nuclear Information System (INIS)

    McCallien, C.W.J.

    1993-02-01

    This report describes a one- two- three-dimensional multi-group diffusion code, SNAP, which is primarily intended for neutron diffusion calculations but can also carry out gamma calculations if the diffusion approximation is accurate enough. It is suitable for fast and thermal reactor core calculations and for shield calculations. SNAP can solve the multi-group neutron diffusion equations using finite difference methods. The one-dimensional slab, cylindrical and spherical geometries and the two-dimensional case are all treated as simple special cases of three-dimensional geometries. Numerous reflective and periodic symmetry options are available and may be used to reduce the number of mesh points necessary to represent the system. Extrapolation lengths can be specified at internal and external boundaries. (Author)

  16. Analysis of three-dimensional transonic compressors

    Science.gov (United States)

    Bourgeade, A.

    1984-01-01

    A method for computing the three-dimensional transonic flow around the blades of a compressor or of a propeller is given. The method is based on the use of the velocity potential, on the hypothesis that the flow is inviscid, irrotational and isentropic. The equation of the potential is solved in a transformed space such that the surface of the blade is mapped into a plane where the periodicity is implicit. This equation is in a nonconservative form and is solved with the help of a finite difference method using artificial time. A computer code is provided and some sample results are given in order to demonstrate the influence of three-dimensional effects and the blade's rotation.

  17. Three-dimensional display of document set

    Science.gov (United States)

    Lantrip, David B [Oxnard, CA; Pennock, Kelly A [Richland, WA; Pottier, Marc C [Richland, WA; Schur, Anne [Richland, WA; Thomas, James J [Richland, WA; Wise, James A [Richland, WA; York, Jeremy [Bothell, WA

    2009-06-30

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  18. Three-dimensional simulation of vortex breakdown

    Science.gov (United States)

    Kuruvila, G.; Salas, M. D.

    1990-01-01

    The integral form of the complete, unsteady, compressible, three-dimensional Navier-Stokes equations in the conservation form, cast in generalized coordinate system, are solved, numerically, to simulate the vortex breakdown phenomenon. The inviscid fluxes are discretized using Roe's upwind-biased flux-difference splitting scheme and the viscous fluxes are discretized using central differencing. Time integration is performed using a backward Euler ADI (alternating direction implicit) scheme. A full approximation multigrid is used to accelerate the convergence to steady state.

  19. Three-dimensional broadband tunable terahertz metamaterials

    DEFF Research Database (Denmark)

    Fan, Kebin; Strikwerda, Andrew; Zhang, Xin

    2013-01-01

    We present optically tunable magnetic three-dimensional (3D) metamaterials at terahertz (THz) frequencies which exhibit a tuning range of ~30% of the resonance frequency. This is accomplished by fabricating 3D array structures consisting of double-split-ring resonators (DSRRs) on silicon on sapph...... as verified through electromagnetic simulations and parameter retrieval. Our approach extends dynamic metamaterial tuning to magnetic control, and may find applications in switching and modulation, polarization control, or tunable perfect absorbers....

  20. Three-Dimensional Ocean Noise Modeling

    Science.gov (United States)

    2015-03-01

    realistic and complex three-dimensional bathymetry. This is achieved by using a parabolic equation [PE) propagation model and the reciprocity principle...explain the horizontal noise directionality observed in the Tonga Trench [Barclay, 2014], which was found not to be a 3D effect, but rather due to...modeled noise arriving on the axis of the canyon has significantly perturbed zero-crossings when compared to the equivalent Nx2D result. Theoretical

  1. Three-dimensional accelerating electromagnetic waves.

    Science.gov (United States)

    Bandres, Miguel A; Alonso, Miguel A; Kaminer, Ido; Segev, Mordechai

    2013-06-17

    We present a general theory of three-dimensional non-paraxial spatially-accelerating waves of the Maxwell equations. These waves constitute a two-dimensional structure exhibiting shape-invariant propagation along semicircular trajectories. We provide classification and characterization of possible shapes of such beams, expressed through the angular spectra of parabolic, oblate and prolate spheroidal fields. Our results facilitate the design of accelerating beams with novel structures, broadening scope and potential applications of accelerating beams.

  2. Multiparallel Three-Dimensional Optical Microscopy

    Science.gov (United States)

    Nguyen, Lam K.; Price, Jeffrey H.; Kellner, Albert L.; Bravo-Zanoquera, Miguel

    2010-01-01

    Multiparallel three-dimensional optical microscopy is a method of forming an approximate three-dimensional image of a microscope sample as a collection of images from different depths through the sample. The imaging apparatus includes a single microscope plus an assembly of beam splitters and mirrors that divide the output of the microscope into multiple channels. An imaging array of photodetectors in each channel is located at a different distance along the optical path from the microscope, corresponding to a focal plane at a different depth within the sample. The optical path leading to each photodetector array also includes lenses to compensate for the variation of magnification with distance so that the images ultimately formed on all the photodetector arrays are of the same magnification. The use of optical components common to multiple channels in a simple geometry makes it possible to obtain high light-transmission efficiency with an optically and mechanically simple assembly. In addition, because images can be read out simultaneously from all the photodetector arrays, the apparatus can support three-dimensional imaging at a high scanning rate.

  3. Three-Dimensional Audio Client Library

    Science.gov (United States)

    Rizzi, Stephen A.

    2005-01-01

    The Three-Dimensional Audio Client Library (3DAudio library) is a group of software routines written to facilitate development of both stand-alone (audio only) and immersive virtual-reality application programs that utilize three-dimensional audio displays. The library is intended to enable the development of three-dimensional audio client application programs by use of a code base common to multiple audio server computers. The 3DAudio library calls vendor-specific audio client libraries and currently supports the AuSIM Gold-Server and Lake Huron audio servers. 3DAudio library routines contain common functions for (1) initiation and termination of a client/audio server session, (2) configuration-file input, (3) positioning functions, (4) coordinate transformations, (5) audio transport functions, (6) rendering functions, (7) debugging functions, and (8) event-list-sequencing functions. The 3DAudio software is written in the C++ programming language and currently operates under the Linux, IRIX, and Windows operating systems.

  4. Three-dimensional metamaterials fabricated using Proton Beam Writing

    Energy Technology Data Exchange (ETDEWEB)

    Bettiol, A.A., E-mail: a.bettiol@nus.edu.sg [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, 2 Science Dr. 3, Singapore 117542 (Singapore); Turaga, S.P.; Yan, Y.; Vanga, S.K. [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, 2 Science Dr. 3, Singapore 117542 (Singapore); Chiam, S.Y. [NUS High School for Maths and Science, 20 Clementi Avenue 1, Singapore 129957 (Singapore)

    2013-07-01

    Proton Beam Writing (PBW) is a direct write lithographic technique that has recently been applied to the fabrication of three dimensional metamaterials. In this work, we show that the unique capabilities of PBW, namely the ability to fabricate arrays of high resolution, high aspect ratio microstructures in polymer or replicated into metal, is well suited to metamaterials research. We have also developed a novel method for selectively electroless plating silver directly onto polymer structures that were fabricated using PBW. This method opens up new avenues for utilizing PBW for making metamaterials and other sub-wavelength metallic structures. Several potential applications of three dimensional metamaterials fabricated using PBW are discussed, including sensing and negative refractive index materials.

  5. Three dimensional illustrating - three-dimensional vision and deception of sensibility

    Directory of Open Access Journals (Sweden)

    Anita Gánóczy

    2009-03-01

    Full Text Available The wide-spread digital photography and computer use gave the opportunity for everyone to make three-dimensional pictures and to make them public. The new opportunities with three-dimensional techniques give chance for the birth of new artistic photographs. We present in detail the biological roots of three-dimensional visualization, the phenomena of movement parallax, which can be used efficiently in making three-dimensional graphics, the Zöllner- and Corridor-illusion. There are present in this paper the visual elements, which contribute to define a plane two-dimensional image in three-dimension: coherent lines, the covering, the measurement changes, the relative altitude state, the abatement of detail profusion, the shadings and the perspective effects of colors.

  6. Three-dimensional analysis of craniofacial bones using three-dimensional computer tomography

    International Nuclear Information System (INIS)

    Ono, Ichiro; Ohura, Takehiko; Kimura, Chu

    1989-01-01

    Three-dimensional computer tomography (3DCT) was performed in patients with various diseases to visualize stereoscopically the deformity of the craniofacial bones. The data obtained were analyzed by the 3DCT analyzing system. A new coordinate system was established using the median sagittal plane of the face (a plane passing through sella, nasion and basion) on the three-dimensional image. Three-dimensional profilograms were prepared for detailed analysis of the deformation of craniofacial bones for cleft lip and palate, mandibular prognathia and hemifacial microsomia. For patients, asymmetry in the frontal view and twist-formed complicated deformities were observed, as well as deformity of profiles in the anteroposterior and up-and-down directions. A newly developed technique allows three-dimensional visualization of changes in craniofacial deformity. It would aid in determining surgical strategy, including crani-facial surgery and maxillo-facial surgery, and in evaluating surgical outcome. (N.K.)

  7. Three-dimensional analysis of craniofacial bones using three-dimensional computer tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Ichiro; Ohura, Takehiko; Kimura, Chu (Hokkaido Univ., Sapporo (Japan). School of Medicine) (and others)

    1989-08-01

    Three-dimensional computer tomography (3DCT) was performed in patients with various diseases to visualize stereoscopically the deformity of the craniofacial bones. The data obtained were analyzed by the 3DCT analyzing system. A new coordinate system was established using the median sagittal plane of the face (a plane passing through sella, nasion and basion) on the three-dimensional image. Three-dimensional profilograms were prepared for detailed analysis of the deformation of craniofacial bones for cleft lip and palate, mandibular prognathia and hemifacial microsomia. For patients, asymmetry in the frontal view and twist-formed complicated deformities were observed, as well as deformity of profiles in the anteroposterior and up-and-down directions. A newly developed technique allows three-dimensional visualization of changes in craniofacial deformity. It would aid in determining surgical strategy, including crani-facial surgery and maxillo-facial surgery, and in evaluating surgical outcome. (N.K.).

  8. Fabrication of malleable three-dimensional-printed customized bolus using three-dimensional scanner.

    Directory of Open Access Journals (Sweden)

    Jae Won Park

    Full Text Available A three-dimensional (3D-printed customized bolus (3D bolus can be used for radiotherapy application to irregular surfaces. However, bolus fabrication based on computed tomography (CT scans is complicated and also delivers unwanted irradiation. Consequently, we fabricated a bolus using a 3D scanner and evaluated its efficacy. The head of an Alderson Rando phantom was scanned with a 3D scanner. The 3D surface data were exported and reconstructed with Geomagic Design X software. A 3D bolus of 5-mm thickness designed to fit onto the nose was printed with the use of rubber-like printing material, and a radiotherapy plan was developed. We successfully fabricated the customized 3D bolus, and further, a CT simulation indicated an acceptable fit of the 3D bolus to the nose. There was no air gap between the bolus and the phantom surface. The percent depth dose (PDD curve of the phantom with the 3D bolus showed an enhanced surface dose when compared with that of the phantom without the bolus. The PDD of the 3D bolus was comparable with that of a commercial superflab bolus. The radiotherapy plan considering the 3D bolus showed improved target coverage when compared with that without the bolus. Thus, we successfully fabricated a customized 3D bolus for an irregular surface using a 3D scanner instead of a CT scanner.

  9. Three-dimensional positioning with optofluidic microscope

    DEFF Research Database (Denmark)

    Vig, Asger Laurberg; Marie, Rodolphe; Jensen, Eric

    2010-01-01

    This paper reports on-chip based optical detection with three-dimensional spatial resolution by integration of an optofluidic microscope (OFM) in a microfluidic pinched flow fractionation (PFF) separation device. This setup also enables on-chip particle image velocimetry (PIV). The position...... a conventional fluorescence microscope as readout. The size separated microspheres are detected by OFM with an accuracy of ≤ 0.92 μm. The position in the height of the channel and the velocity of the separated microspheres are detected with an accuracy of 1.4 μm and 0.08 mm/s respectively. Throughout...

  10. Three Dimensional Double Layers in Magnetized Plasmas

    DEFF Research Database (Denmark)

    Jovanovic, D.; Lynov, Jens-Peter; Michelsen, Poul

    1982-01-01

    Experimental results are presented which demonstrate the formation of fully three dimensional double layers in a magnetized plasma. The measurements are performed in a magnetized stationary plasma column with radius 1.5 cm. Double layers are produced by introducing an electron beam with radius 0.......4 cm along the magnetic field from one end of the column. The voltage drop across the double layer is found to be determined by the energy of the incoming electron beam. In general we find that the width of the double layer along the external magnetic field is determined by plasma density and beam...

  11. Three-Dimensional Printing in Orthopedic Surgery.

    Science.gov (United States)

    Eltorai, Adam E M; Nguyen, Eric; Daniels, Alan H

    2015-11-01

    Three-dimensional (3D) printing is emerging as a clinically promising technology for rapid prototyping of surgically implantable products. With this commercially available technology, computed tomography or magnetic resonance images can be used to create graspable objects from 3D reconstructed images. Models can enhance patients' understanding of their pathology and surgeon preoperative planning. Customized implants and casts can be made to match an individual's anatomy. This review outlines 3D printing, its current applications in orthopedics, and promising future directions. Copyright 2015, SLACK Incorporated.

  12. Three-dimensional teletherapy treatment planning

    International Nuclear Information System (INIS)

    Panthaleon van Eck, R.B. van.

    1986-01-01

    This thesis deals with physical/mathematical backgrounds of computerized teletherapy treatment planning. The subjects discussed in this thesis can be subdivided into three main categories: a) Three-dimensional treatment planning. A method is evaluated which can be used for the purpose of simulation and optimization of dose distributions in three dimensions. b) The use of Computed Tomography. The use of patient information obtained from Computed Tomography for the purpose of dose computations is evaluated. c) Dose computational models for photon- and electron beams. Models are evaluated which provide information regarding the way in which the radiation dose is distributed in the patient (viz. is absorbed and/or dispersed). (Auth.)

  13. Creating three-dimensional thermal maps

    CSIR Research Space (South Africa)

    Price

    2011-11-01

    Full Text Available stream_source_info Price_2011.pdf.txt stream_content_type text/plain stream_size 30895 Content-Encoding ISO-8859-1 stream_name Price_2011.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Creating Three...-Dimensional Thermal Maps Mathew Price Cogency cc Cape Town Email: mathew@cogency.co.za Jeremy Green CSIR Centre for Mining Innovation Johannesburg Email: jgreen@csir.co.za John Dickens CSIR Centre for Mining Innovation Johannesburg Email: jdickens...

  14. Three-dimensional cooling of muons

    CERN Document Server

    Vsevolozhskaya, T A

    2000-01-01

    The simultaneous ionization cooling of muon beams in all three - the longitudinal and two transverse - directions is considered in a scheme, based on bent lithium lenses with dipole constituent of magnetic field in them, created by a special configuration of current-carrying rod. An analysis of three-dimensional cooling is performed with the use of kinetic equation method. Results of numerical calculation for a specific beam line configuration are presented together with results of computer simulation using the Moliere distribution to describe the Coulomb scattering and the Vavilov distribution used to describe the ionization loss of energy.

  15. Three-dimensional radiation treatment planning

    International Nuclear Information System (INIS)

    Mohan, R.

    1989-01-01

    A major aim of radiation therapy is to deliver sufficient dose to the tumour volume to kill the cancer cells while sparing the nearby health organs to prevent complications. With the introduction of devices such as CT and MR scanners, radiation therapy treatment planners have access to full three-dimensional anatomical information to define, simulate, and evaluate treatments. There are a limited number of prototype software systems that allow 3D treatment planning currently in use. In addition, there are more advanced tools under development or still in the planning stages. They require sophisticated graphics and computation equipment, complex physical and mathematical algorithms, and new radiation treatment machines that deliver dose very precisely under computer control. Components of these systems include programs for the identification and delineation of the anatomy and tumour, the definition of radiation beams, the calculation of dose distribution patterns, the display of dose on 2D images and as three dimensional surfaces, and the generation of computer images to verify proper patient positioning in treatment. Some of these functions can be performed more quickly and accurately if artificial intelligence or expert systems techniques are employed. 28 refs., figs

  16. Three dimensional animated images of anorectal malformations

    International Nuclear Information System (INIS)

    Ueno, Shigeru; Yanagimachi, Noriharu; Muro, Isao; Komiya, Taizo; Yokoyama, Seishichi; Hirakawa, Hitoshi; Tajima, Tomoo; Mitomi, Toshio; Suto, Yasuzo.

    1996-01-01

    Accurate reconstruction of the pelvic structures is a most important factor in obtaining a desirable result after anorectoplasty for a patient with anorectal malformation. Preoperative evaluation of the anatomy is indispensable for choosing an appropriate operative method in each case. To facilitate preoperative evaluation, three dimensional animated images of the pelvic structure of patients with anorectal malformations were constructed by computer graphics based upon tomographic images obtained from magnetic resonance imaging. Axial 1-mm thick images of the pelvic portion were generated with spoiling pulse gradient echo sequences using short repetition times (13 msec TR) and short echo times (6 msec TE) with a flip angle of 25 degrees with the patient in the jack-knife position. Graphic data from MR images were transferred to a graphic work station and processed on it. The skin surface, the ano-rectum, the lower urinary tract and the sphincter musculature were segmented by thresholding images by the signal intensity. Three dimensional images were displayed by surface rendering method using the segmented data of each organ and then animation images of these organs were obtained. The anatomy of each type of anomaly was easily recognized by 3-D visualization, and animation of the pelvic viscera and the sphincter musculature made the images more realistic. Animated images of the musculature were especially useful for simulating surgical procedures and could be helpful for reviewing surgical results. (author)

  17. The Three-Dimensional Universe with Gaia

    Science.gov (United States)

    Turon, C.; O'Flaherty, K. S.; Perryman, M. A. C.

    2005-01-01

    "The Three-Dimensional Universe with Gaia" symposium was hosted by the Observatoire de Paris (Meudon), France, from 4 to 7 October 2004. The date chosen for this symposium corresponded to the end of the definition phase of Gaia, a cornerstone mission of the European Space Agency. The purposes of this symposium were: (1) to present to the scientific community the design chosen for the mission, the final characteristics and performances, and to update the resulting scientific case; (2) to bring to the attention of the scientific community the extraordinary potential of Gaia and to share with the younger generation of scientists the expertise acquired during the preparation phases of the Gaia mission, and during all phases of the Hipparcos mission; (3) to organise the next phase of scientific preparation of the mission, in particular the data reduction which constitutes a major challenge with a petabyte of interconnected data which has to be treated in a global and iterative manner, and to prepare for the scientific exploitation of the data. The symposium was open to scientists working on the preparation of Gaia and to the large community interested in using the data from the mission. The proceedings of the symposium are published by the European Space Agency as ESA SP-576: "The Three-Dimensional Universe with Gaia". These proceedings contain invited and contributed papers for six sessions covering technical and scientific aspects of the mission.

  18. Three-dimensional electrical impedance tomography

    Science.gov (United States)

    Metherall, P.; Barber, D. C.; Smallwood, R. H.; Brown, B. H.

    1996-04-01

    THE electrical resistivity of mammalian tissues varies widely1-5 and is correlated with physiological function6-8. Electrical impedance tomography (EIT) can be used to probe such variations in vivo, and offers a non-invasive means of imaging the internal conductivity distribution of the human body9-11. But the computational complexity of EIT has severe practical limitations, and previous work has been restricted to considering image reconstruction as an essentially two-dimensional problem10,12. This simplification can limit significantly the imaging capabilities of EIT, as the electric currents used to determine the conductivity variations will not in general be confined to a two-dimensional plane13. A few studies have attempted three-dimensional EIT image reconstruction14,15, but have not yet succeeded in generating images of a quality suitable for clinical applications. Here we report the development of a three-dimensional EIT system with greatly improved imaging capabilities, which combines our 64-electrode data-collection apparatus16 with customized matrix inversion techniques. Our results demonstrate the practical potential of EIT for clinical applications, such as lung or brain imaging and diagnostic screening8.

  19. Three-dimensional turbopump flowfield analysis

    Science.gov (United States)

    Sharma, O. P.; Belford, K. A.; Ni, R. H.

    1992-01-01

    A program was conducted to develop a flow prediction method applicable to rocket turbopumps. The complex nature of a flowfield in turbopumps is described and examples of flowfields are discussed to illustrate that physics based models and analytical calculation procedures based on computational fluid dynamics (CFD) are needed to develop reliable design procedures for turbopumps. A CFD code developed at NASA ARC was used as the base code. The turbulence model and boundary conditions in the base code were modified, respectively, to: (1) compute transitional flows and account for extra rates of strain, e.g., rotation; and (2) compute surface heat transfer coefficients and allow computation through multistage turbomachines. Benchmark quality data from two and three-dimensional cascades were used to verify the code. The predictive capabilities of the present CFD code were demonstrated by computing the flow through a radial impeller and a multistage axial flow turbine. Results of the program indicate that the present code operated in a two-dimensional mode is a cost effective alternative to full three-dimensional calculations, and that it permits realistic predictions of unsteady loadings and losses for multistage machines.

  20. Exact solutions in three-dimensional gravity

    CERN Document Server

    Garcia-Diaz, Alberto A

    2017-01-01

    A self-contained text, systematically presenting the determination and classification of exact solutions in three-dimensional Einstein gravity. This book explores the theoretical framework and general physical and geometrical characteristics of each class of solutions, and includes information on the researchers responsible for their discovery. Beginning with the physical character of the solutions, these are identified and ordered on the basis of their geometrical invariant properties, symmetries, and algebraic classifications, or from the standpoint of their physical nature, for example electrodynamic fields, fluid, scalar field, or dilaton. Consequently, this text serves as a thorough catalogue on 2+1 exact solutions to the Einstein equations coupled to matter and fields, and on vacuum solutions of topologically massive gravity with a cosmological constant. The solutions are also examined from different perspectives, enabling a conceptual bridge between exact solutions of three- and four-dimensional gravit...

  1. AAOGlimpse: Three-dimensional Data Viewer

    Science.gov (United States)

    Shortridge, Keith

    2011-10-01

    AAOGlimpse is an experimental display program that uses OpenGL to display FITS data (and even JPEG images) as 3D surfaces that can be rotated and viewed from different angles, all in real-time. It is WCS-compliant and designed to handle three-dimensional data. Each plane in a data cube is surfaced in the same way, and the program allows the user to travel through a cube by 'peeling off' successive planes, or to look into a cube by suppressing the display of data below a given cutoff value. It can blink images and can superimpose images and contour maps from different sources using their world coordinate data. A limited socket interface allows communication with other programs.

  2. THE THREE DIMENSIONAL THERMAL HYDRAULIC CODE BAGIRA.

    Energy Technology Data Exchange (ETDEWEB)

    KALINICHENKO,S.D.; KOHUT,P.; KROSHILIN,A.E.; KROSHILIN,V.E.; SMIRNOV,A.V.

    2003-05-04

    BAGIRA - a thermal-hydraulic program complex was primarily developed for using it in nuclear power plant simulator models, but is also used as a best-estimate analytical tool for modeling two-phase mixture flows. The code models allow consideration of phase transients and the treatment of the hydrodynamic behavior of boiling and pressurized water reactor circuits. It provides the capability to explicitly model three-dimensional flow regimes in various regions of the primary and secondary circuits such as, the mixing regions, circular downcomer, pressurizer, reactor core, main primary loops, the steam generators, the separator-reheaters. In addition, it is coupled to a severe-accident module allowing the analysis of core degradation and fuel damage behavior. Section II will present the theoretical basis for development and selected results are presented in Section III. The primary use for the code complex is to realistically model reactor core behavior in power plant simulators providing enhanced training tools for plant operators.

  3. Entanglement entropy in three dimensional gravity

    Energy Technology Data Exchange (ETDEWEB)

    Maxfield, Henry [Centre for Particle Theory & Department of Mathematical Sciences, Durham University,South Road, Durham DH1 3LE (United Kingdom)

    2015-04-07

    The Ryu-Takayanagi (RT) and covariant Hubeny-Rangamani-Takayanagi (HRT) proposals relate entanglement entropy in CFTs with holographic duals to the areas of minimal or extremal surfaces in the bulk geometry. We show how, in three dimensional pure gravity, the relevant regulated geodesic lengths can be obtained by writing a spacetime as a quotient of AdS{sub 3}, with the problem reduced to a simple purely algebraic calculation. We explain how this works in both Lorentzian and Euclidean formalisms, before illustrating its use to obtain novel results in a number of examples, including rotating BTZ, the ℝℙ{sup 2} geon, and several wormhole geometries. This includes spatial and temporal dependence of single-interval entanglement entropy, despite these symmetries being broken only behind an event horizon. We also discuss considerations allowing HRT to be derived from analytic continuation of Euclidean computations in certain contexts, and a related class of complexified extremal surfaces.

  4. Three-dimensional printing physiology laboratory technology.

    Science.gov (United States)

    Sulkin, Matthew S; Widder, Emily; Shao, Connie; Holzem, Katherine M; Gloschat, Christopher; Gutbrod, Sarah R; Efimov, Igor R

    2013-12-01

    Since its inception in 19th-century Germany, the physiology laboratory has been a complex and expensive research enterprise involving experts in various fields of science and engineering. Physiology research has been critically dependent on cutting-edge technological support of mechanical, electrical, optical, and more recently computer engineers. Evolution of modern experimental equipment is constrained by lack of direct communication between the physiological community and industry producing this equipment. Fortunately, recent advances in open source technologies, including three-dimensional printing, open source hardware and software, present an exciting opportunity to bring the design and development of research instrumentation to the end user, i.e., life scientists. Here we provide an overview on how to develop customized, cost-effective experimental equipment for physiology laboratories.

  5. Electron in three-dimensional momentum space

    Science.gov (United States)

    Bacchetta, Alessandro; Mantovani, Luca; Pasquini, Barbara

    2016-01-01

    We study the electron as a system composed of an electron and a photon, using lowest-order perturbation theory. We derive the leading-twist transverse-momentum-dependent distribution functions for both the electron and photon in the dressed electron, thereby offering a three-dimensional description of the dressed electron in momentum space. To obtain the distribution functions, we apply both the formalism of the light-front wave function overlap representation and the diagrammatic approach. We perform the calculations both in light-cone gauge and Feynman gauge, and we present a detailed discussion of the role of the Wilson lines to obtain gauge-independent results. We provide numerical results and plots for many of the computed distributions.

  6. Towards microscale electrohydrodynamic three-dimensional printing

    International Nuclear Information System (INIS)

    He, Jiankang; Xu, Fangyuan; Cao, Yi; Liu, Yaxiong; Li, Dichen

    2016-01-01

    It is challenging for the existing three-dimensional (3D) printing techniques to fabricate high-resolution 3D microstructures with low costs and high efficiency. In this work we present a solvent-based electrohydrodynamic 3D printing technique that allows fabrication of microscale structures like single walls, crossed walls, lattice and concentric circles. Process parameters were optimized to deposit tiny 3D patterns with a wall width smaller than 10 μm and a high aspect ratio of about 60. Tight bonding among neighbour layers could be achieved with a smooth lateral surface. In comparison with the existing microscale 3D printing techniques, the presented method is low-cost, highly efficient and applicable to multiple polymers. It is envisioned that this simple microscale 3D printing strategy might provide an alternative and innovative way for application in MEMS, biosensor and flexible electronics. (paper)

  7. An Introduction of Three-dimensional Grammar

    Directory of Open Access Journals (Sweden)

    Fan Xiao

    2017-12-01

    Full Text Available This paper introduces some key points of Three-dimensional Grammar. As for the structure, it can be distinguished into syntactic structure, semantic structure and pragmatic structure from the perspectives of syntax, semantics and pragmatics. And the same is true with the followings, such as grammatical constituents, grammatical functions, grammatical meanings, grammatical focuses. Sentence types which is called sentence pattern, sentence model and sentence types respectively, and analysis methods. This paper proposes that grammatical researches should be done in accordance with the four principles, that is form and meaning co-verified, static and dynamic co-referenced, structure and function co-testified and description and interpretation co-promoted.

  8. Three-dimensional echocardiography in valve disease

    Directory of Open Access Journals (Sweden)

    Cesare Fiorentini

    2009-08-01

    Full Text Available This review covers the role of three-dimensional (3D echocardiography in the diagnosis of heart valve disease. Several factors have contributed to the evolution of this technique, which is currently a simple and routine method: rapid evolution in probe and computer technologies, demonstration that 3D data sets allowed more complete and accurate evaluation of cardiac structures, emerging clinical experience indicating the strong potential particularly in valve diseases, volume and function of the two ventricle measurements and several other fields. This report will review current and future applications of 3D echocardiography in mitral, aortic and tricuspid valve diseases underlying both qualitative (morphologic and quantitative advantages of this technique. (Heart International 2007; 3: 35-41

  9. Method for Parametric Design of Three-Dimensional Shapes

    National Research Council Canada - National Science Library

    Dick, James L

    2006-01-01

    The present invention relates to computer-aided design of three-dimensional shapes and more particularly, relates to a system and method for parametric design of three-dimensional hydrodynamic shapes...

  10. Three-dimensional (3D) analysis of the temporomandibular joint

    DEFF Research Database (Denmark)

    Kitai, N.; Kreiborg, S.; Murakami, S.

    Symposium Orthodontics 2001: Where are We Now? Where are We Going?, three-dimensional analysis, temporomandibular joint......Symposium Orthodontics 2001: Where are We Now? Where are We Going?, three-dimensional analysis, temporomandibular joint...

  11. Architecture and Applications of Functional Three-Dimensional Graphene Networks

    DEFF Research Database (Denmark)

    Dey, Ramendra Sundar; Chi, Qijin

    2015-01-01

    building blocksfor the bottom-up architecture of various graphene based nanomaterials. Th eassembly of functionalized GNS into three-dimensional (3D) porous graphenenetworks represents a novel approach. Resulting 3D porous graphene materialsposses unique physicochemical properties such as large surface......As the fi rst atomic-thick two-dimensional crystalline material, graphene has continuouslycreated a wonder land in materials science within the past decade. Anumber of methods have been developed for preparation and functionalizationof single-layered graphene nanosheets (GNS), which are essential...... areas, goodconductivity and mechanical strength, high thermal stability and desirable fl exibility,which altogether makes this new type of porous materials be highly attractivefor a wide range of applications. In this chapter, we will cover some crucialaspects of porous graphene networked materials...

  12. Study on three dimensional seismic isolation system

    International Nuclear Information System (INIS)

    Morishita, Masaki; Kitamura, Seiji

    2003-01-01

    Japan Nuclear Cycle Development Institute (JNC) and Japan Atomic Power Company (JAPC) launched joint research programs on structural design and three-dimensional seismic isolation technologies, as part of the supporting R and D activities for the feasibility studies on commercialized fast breeder reactor cycle systems. A research project by JAPC under the auspices of the Ministry of Economy, Trade, and Industry (METI) with technical support by JNC is included in this joint study. This report contains the results of the research on the three-dimensional seismic isolation technologies, and the results of this year's study are summarized in the following five aspects. (1) Study on Earthquake Condition for Developing 3-dimensional Base Isolation System. The case study S2 is one of the maximum ground motions, of which the records were investigated up to this time. But a few observed near the fault exceed the case study S2 in the long period domain, depending on the fault length and conditions. Generally it is appropriate that the response spectra ratio (vertical/horizontal) is 0.6. (2) Performance Requirement for 3-dimensional Base Isolation System and Devices. Although the integrity map of main equipment/piping dominate the design criteria for the 3-dimensional base isolation system, the combined integrity map is the same as those of FY 2000, which are under fv=1Hz and over hv=20%. (3) Developing Targets and Schedule for 3-dimensional Isolation Technology. The target items for 3-dimensional base isolation system were rearranged into a table, and developing items to be examined concerning the device were also adjusted. A development plan until FY 2009 was made from the viewpoint of realization and establishment of a design guideline on 3-dimensional base isolation system. (4) Study on 3-dimensional Entire Building Base Isolation System. Three ideas among six ideas that had been proposed in FY2001, i.e., '3-dimensional base isolation system incorporating hydraulic

  13. Tailoring thermal conductivity via three-dimensional porous alumina.

    Science.gov (United States)

    Abad, Begoña; Maiz, Jon; Ruiz-Clavijo, Alejandra; Caballero-Calero, Olga; Martin-Gonzalez, Marisol

    2016-12-09

    Three-dimensional anodic alumina templates (3D-AAO) are an astonishing framework with open highly ordered three-dimensional skeleton structures. Since these templates are architecturally different from conventional solids or porous templates, they teem with opportunities for engineering thermal properties. By establishing the mechanisms of heat transfer in these frameworks, we aim to create materials with tailored thermal properties. The effective thermal conductivity of an empty 3D-AAO membrane was measured. As the effective medium theory was not valid to extract the skeletal thermal conductivity of 3D-AAO, a simple 3D thermal conduction model was developed, based on a mixed series and parallel thermal resistor circuit, giving a skeletal thermal conductivity value of approximately 1.25 W·m -1 ·K -1 , which matches the value of the ordinary AAO membranes prepared from the same acid solution. The effect of different filler materials as well as the variation of the number of transversal nanochannels and the length of the 3D-AAO membrane in the effective thermal conductivity of the composite was studied. Finally, the thermal conductivity of two 3D-AAO membranes filled with cobalt and bismuth telluride was also measured, which was in good agreement with the thermal model predictions. Therefore, this work proved this structure as a powerful approach to tailor thermal properties.

  14. Tailoring thermal conductivity via three-dimensional porous alumina

    Science.gov (United States)

    Abad, Begoña; Maiz, Jon; Ruiz-Clavijo, Alejandra; Caballero-Calero, Olga; Martin-Gonzalez, Marisol

    2016-01-01

    Three-dimensional anodic alumina templates (3D-AAO) are an astonishing framework with open highly ordered three-dimensional skeleton structures. Since these templates are architecturally different from conventional solids or porous templates, they teem with opportunities for engineering thermal properties. By establishing the mechanisms of heat transfer in these frameworks, we aim to create materials with tailored thermal properties. The effective thermal conductivity of an empty 3D-AAO membrane was measured. As the effective medium theory was not valid to extract the skeletal thermal conductivity of 3D-AAO, a simple 3D thermal conduction model was developed, based on a mixed series and parallel thermal resistor circuit, giving a skeletal thermal conductivity value of approximately 1.25 W·m−1·K−1, which matches the value of the ordinary AAO membranes prepared from the same acid solution. The effect of different filler materials as well as the variation of the number of transversal nanochannels and the length of the 3D-AAO membrane in the effective thermal conductivity of the composite was studied. Finally, the thermal conductivity of two 3D-AAO membranes filled with cobalt and bismuth telluride was also measured, which was in good agreement with the thermal model predictions. Therefore, this work proved this structure as a powerful approach to tailor thermal properties. PMID:27934930

  15. Multimodal three-dimensional dynamic signature

    Directory of Open Access Journals (Sweden)

    Yury E. Kozlov

    2017-11-01

    Full Text Available Reliable authentication in mobile applications is among the most important information security challenges. Today, we can hardly imagine a person who would not own a mobile device that connects to the Internet. Mobile devices are being used to store large amounts of confidential information, ranging from personal photos to electronic banking tools. In 2009, colleagues from Rice University together with their collaborators from Motorola, proposed an authentication through in-air gestures. This and subsequent work contributing to the development of the method are reviewed in our introduction. At the moment, there exists a version of the gesture-based authentication software available for Android mobile devices. This software has not become widespread yet. One of likely reasons for that is the insufficient reliability of the method, which involves similar to its earlier analogs the use of only one device. Here we discuss the authentication based on the multimodal three-dimensional dynamic signature (MTDS performed by two independent mobile devices. The MTDS-based authentication technique is an advanced version of in-air gesture authentication. We describe the operation of a prototype of MTDS-based authentication, including the main implemented algorithms, as well as some preliminary results of testing the software. We expect that our method can be used in any mobile application, provided a number of additional improvements discussed in the conclusion are made.

  16. Three-dimensional supersonic vortex breakdown

    Science.gov (United States)

    Kandil, Osama A.; Kandil, Hamdy A.; Liu, C. H.

    1993-01-01

    Three-dimensional supersonic vortex-breakdown problems in bound and unbound domains are solved. The solutions are obtained using the time-accurate integration of the unsteady, compressible, full Navier-Stokes (NS) equations. The computational scheme is an implicit, upwind, flux-difference splitting, finite-volume scheme. Two vortex-breakdown applications are considered in the present paper. The first is for a supersonic swirling jet which is issued from a nozzle into a supersonic uniform flow at a lower Mach number than that of the swirling jet. The second is for a supersonic swirling flow in a configured circular duct. In the first application, an extensive study of the effects of grid fineness, shape and grid-point distribution on the vortex breakdown is presented. Four grids are used in this study and they show a substantial dependence of the breakdown bubble and shock wave on the grid used. In the second application, the bubble-type and helix-type vortex breakdown have been captured.

  17. Three-dimensional endoscopy in sinus surgery.

    Science.gov (United States)

    Singh, Ameet; Saraiya, Rupali

    2013-02-01

    Surgical endoscopy revolutionized the management of disease in nearly every surgical field, including rhinology. Endoscopy offered several advantages for the surgical management of rhinologic disease. However, it had a distinct disadvantage compared to direct vision, namely loss of binocular vision. Two-dimensional (2D) endoscopy limited depth perception, widely regarded as an important parameter for accurate and efficient movements during surgery. Three-dimensional (3D) endoscopic visualization has been actively pursued for decades by endoscopic surgeons in multiple surgical specialties. However, its clinical role has been limited due to technical limitations as well as successful adaptation by endoscopic surgeons to monocular cues offered by 2D technology. Until recently, stereoscopic technology included variations of dual channel video, dual chip-on-the-tip, and shutter mechanism, as well as various 3D displays. Over the past decade a novel 3D endoscopic technology was introduced. This technology used a lenticular array of lenses in front of a single video chip at the distal end of an endoscope to generate a stereoscopic view of the surgical field. Also known as the 'insect eye' technology since it mimics the compound eye of arthropods, this endoscope has reinvigorated the field of 3D endoscopic surgery. Recent developments in 3D endoscopy hold much promise for all surgical subspecialties, particularly endoscopic sinus and skull-base surgery.

  18. Three-dimensional laparoscopy: Principles and practice

    Directory of Open Access Journals (Sweden)

    Rakesh Y Sinha

    2017-01-01

    Full Text Available The largest challenge for laparoscopic surgeons is the eye–hand coordination within a three-dimensional (3D scene observed on a 2D display. The 2D view on flat screen laparoscopy is cerebrally intensive. The loss of binocular vision on a 2D display causes visual misperceptions, mainly loss of depth perception and adds to the surgeon's fatigue. This compromises the safety of laparoscopy. The 3D high-definition view with great depth perception and tactile feedback makes laparoscopic surgery more acceptable, safe and cost-effective. It improves surgical precision and hand–eye coordination, conventional and all straight stick instruments can be used, capital expenditure is less and recurring cost and annual maintenance cost are less. In this article, we have discussed the physics of 3D laparoscopy, principles of depth perception, and the different kinds of 3D systems available for laparoscopy. We have also discussed our experience of using 3D laparoscopy in over 2000 surgeries in the last 4 years.

  19. Nanoscale three-dimensional single particle tracking.

    Science.gov (United States)

    Dupont, Aurélie; Lamb, Don C

    2011-11-01

    Single particle tracking (SPT) in biological systems is a quickly growing field. Many new technologies are being developed providing new tracking capabilities, which also lead to higher demands and expectations for SPT. Following a single biomolecule as it performs its function provides quantitative mechanistic information that cannot be obtained in classical ensemble methods. From the 3D trajectory, information is available over the diffusional behavior of the particle and precise position information can also be used to elucidate interactions of the tracked particle with its surroundings. Thus, three-dimensional (3D) SPT is a very valuable tool for investigating cellular processes. This review presents recent progress in 3D SPT, from image-based techniques toward more sophisticated feedback approaches. We focus mainly on the feedback technique known as orbital tracking. We present here a modified version of the original orbital tracking in which the intensities from two z-planes are simultaneously measured allowing a concomitant wide-field imaging. The system can track single particles with a precision down to 5 nm in the x-y plane and 7 nm in the axial direction. The capabilities of the system are demonstrated using single virus tracing to follow the infection pathway of Prototype Foamy Virus in living cells.

  20. THREE-DIMENSIONAL ULTRASOUND IN GYNECOLOGIC ONCOLOGY

    Directory of Open Access Journals (Sweden)

    Iztok Takač

    2003-12-01

    Full Text Available Background. Although three-dimensional ultrasound (3D US imaging has been used for a decade, debate continues about its potential clinical aplications in gynecology. The same is true for the field of gynecologic oncology. Also, reports regarding usfulness of 3D US in gynecologic oncology are limited. A few potentially useful clinical applications have been described and some of these are now gaining general acceptance. In this paper, the usfulness of 3D US in the main areas of its application is demonstrated: diagnostics of cervical, endometrial, ovarian and breast cancer.Conclusions. An important advantage of 3D US over conventional two-dimensional imaging is the ability to reconstruct and display any arbitrarily chosen section within the volume dataset as well as ability to measure the volume of pelvic organs regardless of their shape. 3D US also allows the realtime analysis of the acquired image data to be conducted at a later time when the patient is off the examination table.

  1. Three-Dimensional Printed Thermal Regulation Textiles.

    Science.gov (United States)

    Gao, Tingting; Yang, Zhi; Chen, Chaoji; Li, Yiju; Fu, Kun; Dai, Jiaqi; Hitz, Emily M; Xie, Hua; Liu, Boyang; Song, Jianwei; Yang, Bao; Hu, Liangbing

    2017-11-28

    Space cooling is a predominant part of energy consumption in people's daily life. Although cooling the whole building is an effective way to provide personal comfort in hot weather, it is energy-consuming and high-cost. Personal cooling technology, being able to provide personal thermal comfort by directing local heat to the thermally regulated environment, has been regarded as one of the most promising technologies for cooling energy and cost savings. Here, we demonstrate a personal thermal regulated textile using thermally conductive and highly aligned boron nitride (BN)/poly(vinyl alcohol) (PVA) composite (denoted as a-BN/PVA) fibers to improve the thermal transport properties of textiles for personal cooling. The a-BN/PVA composite fibers are fabricated through a fast and scalable three-dimensional (3D) printing method. Uniform dispersion and high alignment of BN nanosheets (BNNSs) can be achieved during the processing of fiber fabrication, leading to a combination of high mechanical strength (355 MPa) and favorable heat dispersion. Due to the improved thermal transport property imparted by the thermally conductive and highly aligned BNNSs, better cooling effect (55% improvement over the commercial cotton fiber) can be realized in the a-BN/PVA textile. The wearable a-BN/PVA textiles containing the 3D-printed a-BN/PVA fibers offer a promising selection for meeting the personal cooling requirement, which can significantly reduce the energy consumption and cost for cooling the whole building.

  2. A method for fabricating a three-dimensional carbon structure

    DEFF Research Database (Denmark)

    2017-01-01

    A method for fabricating a three-dimensional carbon structure (4) is disclosed. A mould (1) defining a three-dimensional shape is provided, and natural protein containing fibres are packed in the mould (1) at a predetermined packing density. The packed natural protein containing fibre structure (3......) undergoes pyrolysis, either while still in the mould (1) or after having been removed from the mould (1). Thereby a three-dimensional porous and electrically conducting carbon structure (4) having a three-dimensional shape defined by the three-dimensional shape of the mould (1) and a porosity defined...

  3. Effects of ductile matrix failure in three dimensional analysis of metal matrix composites

    DEFF Research Database (Denmark)

    Tvergaard, Viggo

    1998-01-01

    Full three dimensional numerical cell model analyses are carried out for a metal reinforced by short fibers, to study the development of ductile matrix failure. A porous ductile material model is used to describe the effect of the nucleation and growth of voids to coalescence. In each case studied...... a rounded vertex on the yield surface. The full three dimensional model is used to study effects of deviations from equal transverse tension in directions perpendicular to the fibers. (C) 1998 Acta Metallurgica Inc....

  4. Magnetic properties of three-dimensional Hubbard-sigma model

    International Nuclear Information System (INIS)

    Yamamoto, Hisashi; Ichinose, Ikuo; Tatara, Gen; Matsui, Tetsuo.

    1989-11-01

    It is broadly viewed that the magnetism may play an important role in the high-T c superconductivity in the lamellar CuO 2 materials. In this paper, based on a Hubbard-inspired CP 1 or S 2 nonlinear σ model, we give a quantitative study of some magnetic properties in and around the Neel ordered state of three-dimensional quantum antiferromagnets such as La 2 CuO 4 with and without small hole doping. Our model is a (3+1) dimensional effective field theory describing the low energy spin dynamics of a three-dimensional Hubbard model with a very weak interlayer coupling. The effect of hole dynamics is taken into account in the leading approximation by substituting the CP 1 coupling with an 'effective' one determined by the concentration and the one-loop correction of hole fermions. A stationary-phase equation for the one-loop effective potential of S 2 model is analyzed numerically. The behavior of Neel temperature, magnetization (long range Neel order), spin correlation length, etc as functions of anisotropic parameter, temperature, hole concentrations, etc are investigated in detail. A phase diagram is also supported by the renormlization group analysis. The results show that our anisotropic field theory model with certain values of parameters could give a reasonably well description of the magnetic properties indicated by some experiments on pure and doped La 2 CuO 4 . (author)

  5. Panoramic three-dimensional CT imaging

    International Nuclear Information System (INIS)

    Kawamata, Akitoshi; Fujishita, Masami

    1998-01-01

    Panoramic radiography is a unique projection technique for producing a single image of both maxillary and mandibular arches and many other anatomical structures. To obtain a similar panoramic image without panoramic radiography system, a modified three-dimensional (3D) CT imaging technique was designed. A set of CT slice image data extending from the chin to the orbit was used for 3D reconstruction. The CT machine used in this study was the X-Vision (TOSHIBA, Japan). The helical scan technique was used. The slice thickness of reconstructed image was one or 1.5 mm. The occlusal plane or Frankfort horizontal (FH) plane was used as the reference line. The resultant slice image data was stored on a magnetic optical disk and then used to create panoramic 3D-CT images on a Macintosh computer systems (Power Macintosh 8600/250, Apple Computer Inc., USA). To create the panoramic 3D-CT image, the following procedure was designed: Design a curved panoramic 3D-CT imaging layer using the imaging layer and the movement of the x-ray beam in panoramic radiography system as a template; Cut this imaging layer from each slice image, then the trimmed image was transformed to a rectangular layer using the ''still image warping'' special effect in the Elastic Reality special effects system (Elastic Reality Inc., USA); Create panoramic 3D-CT image using the Voxel View (Vital Images Inc., USA) rendering system and volume rendering technique. Although the image quality was primitive, a panoramic view of maxillofacial region was obtained by this technique. (author)

  6. Measurements using three-dimensional product imaging

    Directory of Open Access Journals (Sweden)

    A. Sioma

    2010-07-01

    Full Text Available This article discusses a method of creating a three-dimensional cast model using vision systems and how that model can be used in thequality assessment process carried out directly on the assembly line. The technology of active vision, consisting in illumination of theobject with a laser beam, was used to create the model. Appropriate configuration of camera position geometry and laser light allows thecollection of height profiles and construction of a 3D model of the product on their basis. The article discusses problems connected with the resolution of the vision system, resolution of the laser beam analysis, and resolution connected with the application of the successive height profiles on sample cast planes. On the basis of the model, measurements allowing assessment of dimension parameters and surface defects of a given cast are presented. On the basis of tests and analyses of such a threedimensional cast model, a range of checks which are possible to conduct using 3D vision systems is indicated.Testing casts using that technology allows rapid assessment of selected parameters. Construction of the product’s model and dimensional assessment take a few seconds, which significantly reduces the duration of checks in the technological process. Depending on the product, a few checks may be carried out simultaneously on the product’s model.The possibility of controlling all outgoing products, and creating and modifying the product parameter control program, makes the solutionhighly flexible, which is confirmed by pilot industrial implementations. The technology will be developed in terms of detection andidentification of surface defects. It is important due to the possibility of using such information for the purposes of selecting technologicalprocess parameters and observing the effect of changes in selected parameters on the cast parameter controlled in a vision system.

  7. Three-dimensional mechanical metamaterials with a twist.

    Science.gov (United States)

    Frenzel, Tobias; Kadic, Muamer; Wegener, Martin

    2017-11-24

    Rationally designed artificial materials enable mechanical properties that are inaccessible with ordinary materials. Pushing on an ordinary linearly elastic bar can cause it to be deformed in many ways. However, a twist, the counterpart of optical activity in the static case, is strictly zero. The unavailability of this degree of freedom hinders applications in terms of mode conversion and the realization of advanced mechanical designs using coordinate transformations. Here, we aim at realizing microstructured three-dimensional elastic chiral mechanical metamaterials that overcome this limitation. On overall millimeter-sized samples, we measure twists per axial strain exceeding 2°/%. Scaling up the number of unit cells for fixed sample dimensions, the twist is robust due to metamaterial stiffening, indicating a characteristic length scale and bringing the aforementioned applications into reach. Copyright © 2017, American Association for the Advancement of Science.

  8. Three-Dimensional Printing of Drug-Eluting Implants

    DEFF Research Database (Denmark)

    Water, Jorrit Jeroen; Bohr, Adam; Bøtker, Johan Peter

    2015-01-01

    The aim of the present work was to investigate the potential of three-dimensional (3D) printing as a manufacturing method for products intended for personalized treatments by exploring the production of novel polylactide-based feedstock materials for 3D printing purposes. Nitrofurantoin (NF......) and hydroxyapatite (HA) were successfully mixed and extruded with up to 30% drug load with and without addition of 5% HA in polylactide strands, which were subsequently 3D-printed into model disc geometries (10 × 2 mm). X-ray powder diffraction analysis showed that NF maintained its anhydrate solid form during...... of custom-made, drug-loaded feedstock materials for 3D printing of pharmaceutical products for controlled release....

  9. Voro++: a three-dimensional Voronoi cell library in C++

    Energy Technology Data Exchange (ETDEWEB)

    Rycroft, Chris

    2009-01-15

    Voro++ is a free software library for the computation of three dimensional Voronoi cells. It is primarily designed for applications in physics and materials science, where the Voronoi tessellation can be a useful tool in the analysis of densely-packed particle systems, such as granular materials or glasses. The software comprises of several C++ classes that can be modified and incorporated into other programs. A command-line utility is also provided that can use most features of the code. Voro++ makes use of a direct cell-by-cell construction, which is particularly suited to handling special boundary conditions and walls. It employs algorithms which are tolerant for numerical precision errors, and it has been successfully employed on very large particle systems.

  10. Mapping three-dimensional temperature in microfluidic chip.

    KAUST Repository

    Wu, Jinbo

    2013-11-25

    Three-dimensional (3D) temperature mapping method with high spatial resolution and acquisition rate is of vital importance in evaluating thermal processes in micro-environment. We have synthesized a new temperature-sensitive functional material (Rhodamine B functionalized Polydimethylsiloxane). By performing optical sectioning of this material, we established an advanced method for visualizing the micro-scale 3D thermal distribution inside microfluidic chip with down to 10 ms temporal resolution and 2 ~ 6 °C temperature resolution depending the capture parameters. This method is successfully applied to monitor the local temperature variation throughout micro-droplet heat transfer process and further reveal exothermic nanoliter droplet reactions to be unique and milder than bench-top experiment.

  11. Three-dimensional structural characterization of nonwoven fabrics.

    Science.gov (United States)

    Venu, Lalith B Suragani; Shim, Eunkyoung; Anantharamaiah, Nagendra; Pourdeyhimi, Behnam

    2012-12-01

    Nonwoven materials are found in a gamut of critical applications. This is partly due to the fact that these structures can be produced at high speed and engineered to deliver unique functionality at low cost. The behavior of these materials is highly dependent on alignment of fibers within the structure. The ability to characterize and also to control the structure is important, but very challenging due to the complex nature of the structures. Thus, to date, focus has been placed mainly on two-dimensional analysis techniques for describing the behavior of nonwovens. This article demonstrates the utility of three-dimensional (3D) digital volumetric imaging technique for visualizing and characterizing a complex 3D class of nonwoven structures produced by hydroentanglement.

  12. Airway branching morphogenesis in three dimensional culture

    Directory of Open Access Journals (Sweden)

    Gudjonsson Thorarinn

    2010-11-01

    Full Text Available Abstract Background Lungs develop from the fetal digestive tract where epithelium invades the vascular rich stroma in a process called branching morphogenesis. In organogenesis, endothelial cells have been shown to be important for morphogenesis and the maintenance of organ structure. The aim of this study was to recapitulate human lung morphogenesis in vitro by establishing a three dimensional (3D co-culture model where lung epithelial cells were cultured in endothelial-rich stroma. Methods We used a human bronchial epithelial cell line (VA10 recently developed in our laboratory. This cell line cell line maintains a predominant basal cell phenotype, expressing p63 and other basal markers such as cytokeratin-5 and -14. Here, we cultured VA10 with human umbilical vein endothelial cells (HUVECs, to mimic the close interaction between these cell types during lung development. Morphogenesis and differentiation was monitored by phase contrast microscopy, immunostainings and confocal imaging. Results We found that in co-culture with endothelial cells, the VA10 cells generated bronchioalveolar like structures, suggesting that lung epithelial branching is facilitated by the presence of endothelial cells. The VA10 derived epithelial structures display various complex patterns of branching and show partial alveolar type-II differentiation with pro-Surfactant-C expression. The epithelial origin of the branching VA10 colonies was confirmed by immunostaining. These bronchioalveolar-like structures were polarized with respect to integrin expression at the cell-matrix interface. The endothelial-induced branching was mediated by soluble factors. Furthermore, fibroblast growth factor receptor-2 (FGFR-2 and sprouty-2 were expressed at the growing tips of the branching structures and the branching was inhibited by the FGFR-small molecule inhibitor SU5402. Discussion In this study we show that a human lung epithelial cell line can be induced by endothelial cells to

  13. The Three-dimensional Digital Factory for Shipbuilding Technology Research

    Directory of Open Access Journals (Sweden)

    Xu Wei

    2016-01-01

    Full Text Available The three-dimensional digital factory technology research is the hotspot in shipbuilding recently. The three-dimensional digital factory technology not only focus on design the components of the product, but also discuss on the simulation and analyses of the production process.Based on the three-dimensional model, the basic data layer, application control layer and the presentation layer of hierarchical structure are established in the three-dimensional digital factory of shipbuilding in this paper. And the key technologies of three-dimensional digital factory of shipbuilding are analysed. Finally, a case study is applied and the results show that the three-dimensional digital factory will play an important role in the future.

  14. Three-dimensional numerical simulation during laser processing of CFRP

    Science.gov (United States)

    Ohkubo, Tomomasa; Sato, Yuji; Matsunaga, Ei-ichi; Tsukamoto, Masahiro

    2017-09-01

    We performed three-dimensional numerical simulation about laser processing of carbon-fiber-reinforced plastic (CFRP) using OpenFOAM as libraries of finite volume method (FVM). Although a little theoretical or numerical studies about heat affected zone (HAZ) formation were performed, there is no research discussing how HAZ is generated considering time development about removal of each material. It is important to understand difference of removal speed of carbon fiber and resin in order to improve quality of cut surface of CFRP. We demonstrated how the carbon fiber and resin are removed by heat of ablation plume by our simulation. We found that carbon fiber is removed faster than resin at first stage because of the difference of thermal conductivity, and after that, the resin is removed faster because of its low combustion temperature. This result suggests the existence of optimal contacting time of the laser ablation and kerf of the target.

  15. Applications of three-dimensional printing technology in urological practice.

    Science.gov (United States)

    Youssef, Ramy F; Spradling, Kyle; Yoon, Renai; Dolan, Benjamin; Chamberlin, Joshua; Okhunov, Zhamshid; Clayman, Ralph; Landman, Jaime

    2015-11-01

    A rapid expansion in the medical applications of three-dimensional (3D)-printing technology has been seen in recent years. This technology is capable of manufacturing low-cost and customisable surgical devices, 3D models for use in preoperative planning and surgical education, and fabricated biomaterials. While several studies have suggested 3D printers may be a useful and cost-effective tool in urological practice, few studies are available that clearly demonstrate the clinical benefit of 3D-printed materials. Nevertheless, 3D-printing technology continues to advance rapidly and promises to play an increasingly larger role in the field of urology. Herein, we review the current urological applications of 3D printing and discuss the potential impact of 3D-printing technology on the future of urological practice. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

  16. Three-dimensional periodic dielectric structures having photonic Dirac points

    Science.gov (United States)

    Bravo-Abad, Jorge; Joannopoulos, John D.; Soljacic, Marin

    2015-06-02

    The dielectric, three-dimensional photonic materials disclosed herein feature Dirac-like dispersion in quasi-two-dimensional systems. Embodiments include a face-centered cubic (fcc) structure formed by alternating layers of dielectric rods and dielectric slabs patterned with holes on respective triangular lattices. This fcc structure also includes a defect layer, which may comprise either dielectric rods or a dielectric slab with patterned with holes. This defect layer introduces Dirac cone dispersion into the fcc structure's photonic band structure. Examples of these fcc structures enable enhancement of the spontaneous emission coupling efficiency (the .beta.-factor) over large areas, contrary to the conventional wisdom that the .beta.-factor degrades as the system's size increases. These results enable large-area, low-threshold lasers; single-photon sources; quantum information processing devices; and energy harvesting systems.

  17. Validation of three-dimensional micro injection molding simulation accuracy

    DEFF Research Database (Denmark)

    Tosello, Guido; Costa, F.S.; Hansen, Hans Nørgaard

    2011-01-01

    the simulation accuracy (i.e. decrease deviations from experimental values): injection speed profile, cavity injection pressure, melt and mold temperatures, three-dimensional mesh parameters, and material rheological characterization. Quality factors investigated for the quantitative comparisons were: short shot...... length, injection pressure profile, molding mass and flow pattern. The importance of calibrated micro molding process monitoring for an accurate implementation strategy of the simulation and its validation has been demonstrated. In fact, inconsistencies and uncertainties in the experimental data must......Data analysis and simulations on micro-molding experiments have been conducted. Micro molding simulations have been executed taking into account actual processing conditions implementation in the software. Various aspects of the simulation set-up have been considered in order to improve...

  18. Phonon band structures of the three dimensional latticed pentamode metamaterials

    Directory of Open Access Journals (Sweden)

    Guan Wang

    2017-02-01

    Full Text Available The artificially designed three-dimensional (3D pentamode metamaterials have such an extraordinary characteristic that the solid materials behave like liquids. Meanwhile, the ideal structure of the pentamode metamaterials arranges in the same way as that of the diamond crystals. In the present research, we regard three types of pentamode metamaterials derived from the 3D crystal lattices as research objects. The phonon band structures of the candidate pentamode structures are calculated by using the finite element method (FEM. We illustrate the relation between the ratio of the bulk modulus B and the shear modulus G of different combinations of D and d. Finally, we find out the relationship between the phonon band structure and the structure parameters. It is useful for generating the phonon band structure and controlling elastic wave propagation.

  19. Quantitative volumetric Raman imaging of three dimensional cell cultures

    KAUST Repository

    Kallepitis, Charalambos

    2017-03-22

    The ability to simultaneously image multiple biomolecules in biologically relevant three-dimensional (3D) cell culture environments would contribute greatly to the understanding of complex cellular mechanisms and cell–material interactions. Here, we present a computational framework for label-free quantitative volumetric Raman imaging (qVRI). We apply qVRI to a selection of biological systems: human pluripotent stem cells with their cardiac derivatives, monocytes and monocyte-derived macrophages in conventional cell culture systems and mesenchymal stem cells inside biomimetic hydrogels that supplied a 3D cell culture environment. We demonstrate visualization and quantification of fine details in cell shape, cytoplasm, nucleus, lipid bodies and cytoskeletal structures in 3D with unprecedented biomolecular specificity for vibrational microspectroscopy.

  20. Is a three-dimensional-printed tooth filling possible?

    Directory of Open Access Journals (Sweden)

    Muhammet Kerim Ayar

    2016-01-01

    Full Text Available Introduction: Three-dimensional (3-D printing is seen as an innovative production process in many fields of dentistry and medicine. But implantation of this novel production process into the treatment of decayed teeth in dentistry remains lacking. Destruction of dental tissues as a result of dental caries is generally treated with dental resin composite fillings. However, a 3-D-printed tooth filling approach, which could be an alternative to traditional approaches, has a potential to reduce treatment costs and technique-sensitivity of the placement of restorative material. The Hypothesis: Here, the hypothesis that a 3-D-printed tooth filling approach could be an alternative to traditional approaches to treatment of decayed teeth is proposed. Evaluation of the Hypothesis: The actual implementation of the 3-D-printed tooth filling technique in the practice of restorative dentistry was discussed in this manuscript.

  1. Engineering three-dimensional cell mechanical microenvironment with hydrogels.

    Science.gov (United States)

    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.

  2. Fabrication of three-dimensional carbon microelectrodes for electrochemical sensing

    DEFF Research Database (Denmark)

    Hemanth, Suhith

    microelectrodes four different model systems (Glucose sensing, Yeast analysis, Dopamine detection in human stem cell and bone cell monitoring) were tested. In all the model systems 3D carbon microelectrodes showed a 2-3 folds higher sensing signal when compared to 2D carbon electrodes.......Carbon microelectrodes have a wide range of applications because of their unique material properties and biocompatibility. The aim of the research work carried out in this thesis was to develop three-dimensional (3D) carbon microelectrodes for electrochemical applications. Three different...... fabrication processes were established for fabrication of 3D carbon microelectrodes using UV photolithography followed by pyrolysis. UV exposure at three different wavelengths 365 nm, 313 nm and 405 nm was optimized to fabricate suspended 3D epoxy polymer templates. The polymer template was pyrolysed at high...

  3. Three-dimensional photonic band gaps in woven structures

    CERN Document Server

    Tsai Ya Chih; Pendry, J B

    1998-01-01

    In this paper, we studied the photonic properties of dielectric fibres woven into three-dimensional (3D) structures. Such fibres can be fabricated on the micrometre scale, and hence the gaps are in the far-infrared to the infrared regime. The vector-wave transfer matrix method is applied to evaluate the photonic band structures. We have also employed the constant-frequency dispersion surface scheme to investigate the development of a full band gap. Such a 3D absolute gap is observed in a rectangular lattice, but at a fairly large dielectric constant for the fibres. Ways to improve on this have been suggested. Our study indicates that woven structures are promising materials for realizing the 3D photonic insulator in the infrared regime. (author)

  4. Exploring Textiles in Architecture through Tangible Three-Dimensional Sketching Tools

    DEFF Research Database (Denmark)

    Heimdal, Elisabeth Jacobsen; Lenau, Torben Anker; O'Mahony, Marie

    for giving form to and joining these materials. The chosen architectural task was how textiles could be used to regulate daylight by applying them to an exterior building skin or to interior spaces. Findings were that three different strategies were used: the tool was used to materialize, illustrate......This paper argues that tangible three dimensional sketching with textiles makes it more likely that these materials will be used when creating architectural spaces. Our research contributes to the more general idea that innovation in architecture and design can be stimulated by the exploration...... of new materials. With tangible three dimensional sketching, we mean an iterative process of physical model making. In two experiments with architectural students, all textile novices, spaces were modelled using a three dimensional sketching tool consisting of textiles, cardboard support and tools...

  5. Three-dimensional reconstruction of the biliary tract using spiral computed tomography. Three-dimensional cholangiography

    International Nuclear Information System (INIS)

    Gon, Masanori; Ogura, Norihiro; Uetsuji, Shouji; Ueyama, Yasuo

    1995-01-01

    In this study, 310 patients with benign biliary diseases, 20 with gallbladder cancer, and 8 with biliary tract carcinoma underwent spiral CT (SCT) scanning at cholangiography. Depiction rate of the shape of the conjunction site of the gallbladder and biliary tract was 27.5% by conventional intravenous cholangiography (DIC), 92.5% by ERC, and 90.0% by DIC-SCT. Abnormal cystic duct course was admitted in 14.1%. Multiplanar reconstruction by DIC-SCT enabled identification of the common bile duct and intrahepatic bile duct stone. Three-dimensional reconstruction of DIC-SCT was effective in evaluating obstruction of the anastomosis or passing condition of after hepatico-jejunostomy. Two-dimensional SCT images through PTCD tube enabled degree of hepatic invasion in bile duct cancer, and three-dimensional images were useful in grasping the morphology of the bile duct branches near the obstruction site. DIC-SCT is therefore considered a useful procedure as non-invasive examination of bile duct lesions. (S.Y.)

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

    Directory of Open Access Journals (Sweden)

    Azad Mashari MD

    2016-12-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  8. Nanoscale effects in the characterization of viscoelastic materials with atomic force microscopy: coupling of a quasi-three-dimensional standard linear solid model with in-plane surface interactions.

    Science.gov (United States)

    Solares, Santiago D

    2016-01-01

    Significant progress has been accomplished in the development of experimental contact-mode and dynamic-mode atomic force microscopy (AFM) methods designed to measure surface material properties. However, current methods are based on one-dimensional (1D) descriptions of the tip-sample interaction forces, thus neglecting the intricacies involved in the material behavior of complex samples (such as soft viscoelastic materials) as well as the differences in material response between the surface and the bulk. In order to begin to address this gap, a computational study is presented where the sample is simulated using an enhanced version of a recently introduced model that treats the surface as a collection of standard-linear-solid viscoelastic elements. The enhanced model introduces in-plane surface elastic forces that can be approximately related to a two-dimensional (2D) Young's modulus. Relevant cases are discussed for single- and multifrequency intermittent-contact AFM imaging, with focus on the calculated surface indentation profiles and tip-sample interaction force curves, as well as their implications with regards to experimental interpretation. A variety of phenomena are examined in detail, which highlight the need for further development of more physically accurate sample models that are specifically designed for AFM simulation. A multifrequency AFM simulation tool based on the above sample model is provided as supporting information.

  9. Three-dimensional Magnetic Resonance Imaging of fossils across taxa

    Directory of Open Access Journals (Sweden)

    D. Mietchen

    2008-01-01

    Full Text Available The frequency of life forms in the fossil record is largely determined by the extent to which they were mineralised at the time of their death. In addition to mineral structures, many fossils nonetheless contain detectable amounts of residual water or organic molecules, the analysis of which has become an integral part of current palaeontological research. The methods available for this sort of investigations, though, typically require dissolution or ionisation of the fossil sample or parts thereof, which is an issue with rare taxa and outstanding materials like pathological or type specimens. In such cases, non-destructive techniques could provide a valuable methodological alternative. While Computed Tomography has long been used to study palaeontological specimens, a number of complementary approaches have recently gained ground. These include Magnetic Resonance Imaging (MRI which had previously been employed to obtain three-dimensional images of pathological belemnites non-invasively on the basis of intrinsic contrast. The present study was undertaken to investigate whether 1H MRI can likewise provide anatomical information about non-pathological belemnites and specimens of other fossil taxa. To this end, three-dimensional MR image series were acquired from intact non-pathological invertebrate, vertebrate and plant fossils. At routine voxel resolutions in the range of several dozens to some hundreds of micrometers, these images reveal a host of anatomical details and thus highlight the potential of MR techniques to effectively complement existing methodological approaches for palaeontological investigations in a wide range of taxa. As for the origin of the MR signal, relaxation and diffusion measurements as well as 1H and 13C MR spectra acquired from a belemnite suggest intracrystalline water or hydroxyl groups, rather than organic residues.

  10. Three-dimensional low-energy topological invariants

    International Nuclear Information System (INIS)

    Bakalarska, M.; Broda, B.

    2000-01-01

    A description of the one-loop approximation formula for the partition function of a three-dimensional abelian version of the Donaldson-Witten theory is proposed. The one-loop expression is shown to contain such topological invariants of a three-dimensional manifold M like the Reidemeister-Ray-Singer torsion τ R and Betti numbers. (orig.)

  11. Collapse in a forced three-dimensional nonlinear Schrodinger equation

    DEFF Research Database (Denmark)

    Lushnikov, P.M.; Saffman, M.

    2000-01-01

    We derive sufficient conditions for the occurrence of collapse in a forced three-dimensional nonlinear Schrodinger equation without dissipation. Numerical studies continue the results to the case of finite dissipation.......We derive sufficient conditions for the occurrence of collapse in a forced three-dimensional nonlinear Schrodinger equation without dissipation. Numerical studies continue the results to the case of finite dissipation....

  12. Three dimensional reductions of four-dimensional quasilinear systems

    Science.gov (United States)

    Pavlov, Maxim V.; Stoilov, Nikola M.

    2017-11-01

    In this paper, we show that four-dimensional quasilinear systems of first order integrable by the method of two-dimensional hydrodynamic reductions possess infinitely many three-dimensional hydrodynamic reductions, which are also integrable systems. These three-dimensional multi-component integrable systems are irreducible to two-dimensional hydrodynamic reductions in a generic case.

  13. Pathogen propagation in cultured three-dimensional tissue mass

    Science.gov (United States)

    Goodwin, Thomas J. (Inventor); Spaulding, Glenn F. (Inventor); Wolf, David A. (Inventor)

    2000-01-01

    A process for propagating a pathogen in a three-dimensional tissue mass cultured at microgravity conditions in a culture vessel containing culture media and a culture matrix is provided. The three-dimensional tissue mass is inoculated with a pathogen and pathogen replication in the cells of the tissue mass achieved.

  14. Three-dimensional plasma equilibrium near a separatrix

    International Nuclear Information System (INIS)

    Reiman, A.H.; Pomphrey, N.; Boozer, A.H.

    1988-08-01

    The limiting behavior of a general three-dimensional MHD equilibrium near a separatrix is calculated explicitly. No expansions in β or assumptions about island widths are made. Implications of the results for the numerical calculation of such equilibria, are discussed, as well as for issues concerning the existence of three-dimensional MHD equilibria. 16 refs., 2 figs

  15. three dimensional photoelastic investigations on thick rectangular ...

    African Journals Online (AJOL)

    user

    1983-09-01

    Sep 1, 1983 ... NIJOTECH VOL. 7. NO. 1 SEPTEMBER 1983 SEBASTIN. 62. Table 2. Material fringe value (fσ), modulus of elasticity (E) and. Poisson's ratio (μ) fσ. E μ. Model Pa-m ... and because of the symmetry in location of the centre slice, equation (2) ... integration of the appropriate stress equation of equilibrium.

  16. Primary and Secondary Three Dimensional Microbatteries

    OpenAIRE

    Cirigliano, Nicolas

    2013-01-01

    Today's MEMS devices are limited more so by the batteries that supply their power than the fabrication methods used to build them. Thick battery electrodes are capable of providing adequate energy, but long and tortuous diffusion pathways lead to low power capabilities. On the other hand, thin film batteries can operate at significant current densities but require large surface areas to supply practical energy. This dilemma can be solved by either developing new high capacity materials or by ...

  17. Three-dimensional analysis of anisotropic spatially reinforced structures

    Science.gov (United States)

    Bogdanovich, Alexander E.

    1993-01-01

    The material-adaptive three-dimensional analysis of inhomogeneous structures based on the meso-volume concept and application of deficient spline functions for displacement approximations is proposed. The general methodology is demonstrated on the example of a brick-type mosaic parallelepiped arbitrarily composed of anisotropic meso-volumes. A partition of each meso-volume into sub-elements, application of deficient spline functions for a local approximation of displacements and, finally, the use of the variational principle allows one to obtain displacements, strains, and stresses at anypoint within the structural part. All of the necessary external and internal boundary conditions (including the conditions of continuity of transverse stresses at interfaces between adjacent meso-volumes) can be satisfied with requisite accuracy by increasing the density of the sub-element mesh. The application of the methodology to textile composite materials is described. Several numerical examples for woven and braided rectangular composite plates and stiffened panels under transverse bending are considered. Some typical effects of stress concentrations due to the material inhomogeneities are demonstrated.

  18. Three-dimensional metrology for printed electronics

    Science.gov (United States)

    Bromberg, Vadim; Harding, Kevin

    2017-05-01

    Novel materials and printing technologies can enable rapid and low cost prototyping and manufacturing of electronic devices with increased flexibility and complexity. However, robust and on-demand printing of circuits will require accurate metrology methods that can measure micron level patterns to verify proper production. This paper presents an evaluation of a range of optical gaging tools ranging from confocal to area 3D systems to determine metrological capability for a range of key parameters from trace thickness to solder paste volumes. Finally, this paper will present a select set of optimized measurement tools detailing both capabilities and gaps in the available technologies needed to fully realize the potential of printed electronics.

  19. Two- and Three-Dimensional Simulations of Asteroid Ocean Impacts

    Science.gov (United States)

    Gisler, G.; Weaver, R. P.; Mader, C. L.; Gittings, M. L.

    2003-01-01

    We have performed a series of two-dimensional and three-dimensional simulations of asteroid impacts into an ocean using the SAGE code from Los Alamos National Laboratory and Science Applications International Corporation. The SAGE code is a compressible Eulerian hydrodynamics code using continuous adaptive mesh refinement for following discontinuities with a fine grid while treating the bulk of the simulation more coarsely. We have used tabular equations of state for the atmosphere, water, the oceanic crust, and the mantle. In two dimensions, we simulated asteroid impactors moving at 20 km/s vertically through an exponential atmosphere into a 5 km deep ocean. The impactors were composed of mantle material (3.32 g/cc) or iron (7.8 g/cc) with diameters from 250m to 10 km. In our three-dimensional runs we simulated asteroids of 1 km diameter composed of iron moving at 20 km/s at angles of 45 and 60 degrees from the vertical. All impacts, including the oblique ones, produce large underwater cavities with nearly vertical walls followed by a collapse starting from the bottom and subsequent vertical jetting. Substantial amounts of water are vaporized and lofted high into the atmosphere. In the larger impacts, significant amounts of crustal and even mantle material are lofted as well. Tsunamis up to a kilometer in initial height are generated by the collapse of the vertical jet. These waves are initially complex in form, and interact strongly with shocks propagating through the water and the crust. The tsunami waves are followed out to 100 km from the point of impact. Their periods and wavelengths show them to be intermediate type waves, and not (in general) shallow-water waves. At great distances, the waves decay faster than the inverse of the distance from the impact point, ignoring sea-floor topography. For all impactors smaller than about 2 km diameter, the impacting body is highly fragmented and its remains lofted into the stratosphere with the water vapor and crustal

  20. TWO- AND THREE-DIMENSIONAL SIMULATIONS OF ASTEROID OCEAN IMPACTS

    Directory of Open Access Journals (Sweden)

    Michael Gittings

    2003-01-01

    Full Text Available We have performed a series of two-dimensional and three-dimensional simulations of asteroid impacts into an ocean using the SAGE code from Los Alamos National Laboratory and Science Applications International Corporation. The SAGE code is a compressible Eulerian hydrodynamics code using continuous adaptive mesh refinement for following discontinuities with a fine grid while treating the bulk of the simulation more coarsely. We have used realistic equations of state for the atmosphere, sea water, the oceanic crust, and the mantle. In two dimensions, we simulated asteroid impactors moving at 20 km/s vertically through an exponential atmosphere into a 5 km deep ocean. The impactors were composed of mantle material (3.32 g/cc or iron (7.8 g/cc with diameters from 250m to 10 km. In our three-dimensional runs we simulated asteroids of 1 km diameter composed of iron moving at 20 km/s at angles of 45 and 60 degrees from the vertical. All impacts, including the oblique ones, produce a large underwater cavities with nearly vertical walls followed by a collapse starting from the bottom and subsequent vertical jetting. Substantial amounts of water are vaporized and lofted high into the atmosphere. In the larger impacts, significant amounts of crustal and even mantle material are lofted as well. Tsunamis up to a kilometer in initial height are generated by the collapse of the vertical jet. These waves are initially complex in form, and interact strongly with shocks propagating through the water and the crust. The tsunami waves are followed out to 100 km from the point of impact. Their periods and wavelengths show them to be intermediate type waves, and not (in general shallow-water waves. At great distances, the waves decay as the inverse of the distance from the impact point, ignoring sea-floor topography. For all impactors smaller than about 2 km diameter, the impacting body is highly fragmented and its remains lofted into the stratosphere with the water

  1. Three-dimensional optical techniques using Dammann gratings

    Science.gov (United States)

    Zhou, Changhe; Yu, Junjie; Wang, Shaoqing; Wei, Shengbin

    2012-11-01

    This paper summarized our work on three-dimensional optical technologies using Dammann gratings, e.g., threedimnensional Dammann gratings, three dimensional imaging using a Dammann grating, etc.. We developed threedimensional Dammann grating which can produce three-dimensional array with equal distance and equal intensity with a high-numerical-aperture lens. As we know, a lens usually has a single focal point. Fresnel zone plate can generate several axial focal points, but the intensity between them is unequal. By introducing the concept of Dammann grating into the circular phase plate, we invented Dammann zone plate(DZP) which can produce a series of axial focal points with equal intensity. Combining DZP with a Dammann grating, three-dimensional Dammann array will be generated, which is highly interesting for various applications. We also built a three-dimensional measuring system using a Dammann grating, with two cameras as the right eye and right eye, respectively. We used a 64×64 Dammann grating for generation of a square array of light spots for parallel capturing the three-dimensional profile of an object. The two cameras and the illuminating part are packaged together. After scanning the object, its three-dimensional profile will be obtained. Experimental results demonstrated the effectiveness of this technique.

  2. Cylindrical Three-Dimensional Porous Anodic Alumina Networks

    Directory of Open Access Journals (Sweden)

    Pedro M. Resende

    2016-11-01

    Full Text Available The synthesis of a conformal three-dimensional nanostructure based on porous anodic alumina with transversal nanopores on wires is herein presented. The resulting three-dimensional network exhibits the same nanostructure as that obtained on planar geometries, but with a macroscopic cylindrical geometry. The morphological analysis of the nanostructure revealed the effects of the initial defects on the aluminum surface and the mechanical strains on the integrity of the three-dimensional network. The results evidence the feasibility of obtaining 3D porous anodic alumina on non-planar aluminum substrates.

  3. Simplified two and three dimensional HTTR benchmark problems

    International Nuclear Information System (INIS)

    Zhang Zhan; Rahnema, Farzad; Zhang Dingkang; Pounders, Justin M.; Ougouag, Abderrafi M.

    2011-01-01

    To assess the accuracy of diffusion or transport methods for reactor calculations, it is desirable to create heterogeneous benchmark problems that are typical of whole core configurations. In this paper we have created two and three dimensional numerical benchmark problems typical of high temperature gas cooled prismatic cores. Additionally, a single cell and single block benchmark problems are also included. These problems were derived from the HTTR start-up experiment. Since the primary utility of the benchmark problems is in code-to-code verification, minor details regarding geometry and material specification of the original experiment have been simplified while retaining the heterogeneity and the major physics properties of the core from a neutronics viewpoint. A six-group material (macroscopic) cross section library has been generated for the benchmark problems using the lattice depletion code HELIOS. Using this library, Monte Carlo solutions are presented for three configurations (all-rods-in, partially-controlled and all-rods-out) for both the 2D and 3D problems. These solutions include the core eigenvalues, the block (assembly) averaged fission densities, local peaking factors, the absorption densities in the burnable poison and control rods, and pin fission density distribution for selected blocks. Also included are the solutions for the single cell and single block problems.

  4. Three dimensional computerized microtomography in the analysis of sculpture.

    Science.gov (United States)

    Badde, Aurelia; Illerhaus, Bernhard

    2008-01-01

    The Alte Nationalgalerie, Staatliche Museen zu Berlin (SMB) and the Federal Institute for Materials Research and Testing (BAM) tested the accomplishment of the three dimensional computerized microtomography (3D-microCT)-a new flat panel detector computerized tomography (CT) system at the BAM with extended energy range, with high voltage X-ray tubes (330 and 225 kV), with micrometer focal spot size and micrometer resolution and enlarged object size (up to 70 cm diameter)-for examining plaster statues. The high spatial and density resolution of the tomograph enable detailed insights into the individual work processes of the investigated cast plaster statues. While initiated in support of the conservation process, computed tomography (CT) analysis has assisted in revealing relative chronologies within the series of the cast works of art, thus serving as a valuable tool in the art-historical appraisal of the oeuvres. The image-processing systems visualize the voids and cracks within and the cuts through the original cast works. Internal structures, armoring, sculptural reworking as well as restorative interventions are virtually reconstructed. The authors are currently employing the 3D-microCT systems at the BAM into the detection of defects in Carrara marble sculpture. Microcracks, fractures, and material flaws are visualized at spatial resolution down to 10 microm. Computerized reconstruction of ultrasound tomography is verified by analyzing correlations in the results obtained from the complementary application of these two non-destructive testing (NDT) methods of diagnosis.

  5. Voludensitometry. Three dimensional display of medical objects

    International Nuclear Information System (INIS)

    Darier, P.; Garderet, P.; Grangeat, P.; Matte, P.; Tournier, E.; Villafana, R.

    1984-05-01

    In order to study the volumic cartography of material density (X-rays imaging), of proton density (RMN imaging) or of specific activity of a marker (γ or β + imaging) a set of calculation results (called voxels) is reconstructed from sensor data collection. Voxels are identified by a triplet of space coordinates and they represent a local estimation of the parameter to be studied. The concepts for representation there upon developed can be extended for any parameter for which additivity is meaningful. The operator has to govern a software in order to work out the documents leading himself to a mental representation of the object. On a display these documents will be either graphics, images or image sequences. The elementary process for elaboration of one image includes: - conditionning the volume: definition of absolute coordinates (geometrical transformations), interactive extraction (surgery) or automation extraction (segmentation) of sub-volumes, contextual organization (sub-volumes ordering, dissolution); - reduction to two dimensions of the information either by spatial integration (radiography), or by surface representation (morphoscopy). This contribution introduces these different concepts showing the way to the design of an interactive display console. Video recorded sequences that have been realised using an experimental software will illustrate the preliminary results [fr

  6. Three-Dimensional Cell Behavior in Microgels

    Science.gov (United States)

    Bhattacharjee, Tapomoy; Palmer, Glyn; Ghivizzani, Steven; Keselowsky, Benjamin; Sawyer, W. Gregory; Angelini, Thomas

    The number of dimensions in which particles can freely move strongly influences the collective behavior that emerges from their individual fluctuations. Thus, in 2D systems of cells in petri-dishes, our growing understanding of collective migration may be insufficient to explain cell behavior in 3D tissues. To study cell behavior in 3D, polymer scaffolds are used. Contemporary designs of 3D cell growth scaffolds enable cell migration and proliferative expansion by incorporating of degradable motifs. Matrix degradation creates space for cells to move and proliferate. However, different cell types and experimental conditions require the design of different scaffolds to optimize degradation with specific cell behaviors. By contrast, liquid like solids made from packed microgels can yield under cell generated stresses, allowing for cell motion without the need for scaffold degradation. Moreover, the use of microgels as 3D culture media allows arranging cells in arbitrary structures, harvesting cells, and delivering drugs and nutrients. Preliminary data describing cell behavior in 3D microgel culture will be presented. This material is based on work supported by the National Science Foundation under Grant No. DMR-1352043.

  7. Fusion of three-dimensional X-ray angiography and three-dimensional echocardiography

    International Nuclear Information System (INIS)

    Rasche, Volker; Mansour, Moussa; Reddy, Vivek; Singh, Jagmeet P.; Ruskin, Jeremy; Qureshi, Answer; Manzke, Robert; Sokka, Sham

    2008-01-01

    Cardiovascular intervention guidance requires knowledge of heart function relative to its blood supply or venous drainage. Functional and vascular anatomic data are usually generated on different imaging systems, so fusion of the data is necessary to simultaneously visualize the results for intervention planning and guidance. The objective of this work is to establish the feasibility of fusing volumetric ultrasound (U/S) data with three-dimensional (3D) X-ray imaging data for visualization of cardiac morphology, function and coronary venous drainage. Temporally resolved U/S volume data was registered with the 3D reconstruction of vascular structures derived from X-ray modeling and reconstruction. U/S image registration was obtained by optical tracking fiducial markers with simultaneous X-ray imaging. The proposed technique was applied to phantom data for accuracy assessment of the registration process and to biventricular pacemaker implantation as clinical example. Fusion of U/S data with 3D X-ray reconstruction data produced an RMS registration error below 2 mm. Preliminary clinical feasibility of U/S-derived data synchronously with X-ray derived 3D coronary venography was established. This technique can be applied for fusion of functional U/S data with 3D anatomic X-ray data of the coronary veins during a biventricular pacemaker implantation procedures. (orig.)

  8. Large three-dimensional photonic crystals based on monocrystalline liquid crystal blue phases.

    Science.gov (United States)

    Chen, Chun-Wei; Hou, Chien-Tsung; Li, Cheng-Chang; Jau, Hung-Chang; Wang, Chun-Ta; Hong, Ching-Lang; Guo, Duan-Yi; Wang, Cheng-Yu; Chiang, Sheng-Ping; Bunning, Timothy J; Khoo, Iam-Choon; Lin, Tsung-Hsien

    2017-09-28

    Although there have been intense efforts to fabricate large three-dimensional photonic crystals in order to realize their full potential, the technologies developed so far are still beset with various material processing and cost issues. Conventional top-down fabrications are costly and time-consuming, whereas natural self-assembly and bottom-up fabrications often result in high defect density and limited dimensions. Here we report the fabrication of extraordinarily large monocrystalline photonic crystals by controlling the self-assembly processes which occur in unique phases of liquid crystals that exhibit three-dimensional photonic-crystalline properties called liquid-crystal blue phases. In particular, we have developed a gradient-temperature technique that enables three-dimensional photonic crystals to grow to lateral dimensions of ~1 cm (~30,000 of unit cells) and thickness of ~100 μm (~ 300 unit cells). These giant single crystals exhibit extraordinarily sharp photonic bandgaps with high reflectivity, long-range periodicity in all dimensions and well-defined lattice orientation.Conventional fabrication approaches for large-size three-dimensional photonic crystals are problematic. By properly controlling the self-assembly processes, the authors report the fabrication of monocrystalline blue phase liquid crystals that exhibit three-dimensional photonic-crystalline properties.

  9. Three-dimensional polypyrrole-derived carbon nanotube framework for dye adsorption and electrochemical supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Shengchang; Yang, Na; Gao, Fei [School of Life Sciences, State Key Laboratory of Coordination Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Institute of Chemistry and BioMedical Sciences, Nanjing University, Nanjing 210093 (China); Zhao, Jing, E-mail: jingzhao@nju.edu.cn [School of Life Sciences, State Key Laboratory of Coordination Chemistry and Collaborative Innovation Center of Chemistry for Life Sciences, Institute of Chemistry and BioMedical Sciences, Nanjing University, Nanjing 210093 (China); Li, Liang, E-mail: msell08@163.com [School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Teng, Chao, E-mail: tengc@pkusz.edu.cn [Guangdong Provincial Key Laboratory of Nano-Micro Materials Research, School of Chemical Biology & Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055 (China)

    2017-08-31

    Highlights: • Three-dimensional polypyrrole-derived carbon nanotube frameworks are prepared. • They display outstanding absorption capacity (609 mg g{sup −1}) towards methylene blue. • They possess high specific capacitance (167 F g{sup −1}) and good rate capability (64%). • They have excellent cycling performance with no capacitance loss over 1000 cycles. - Abstract: Three-dimensional carbon nanotube frameworks have been prepared via pyrolysis of polypyrrole nanotube aerogels that are synthesized by the simultaneous self-degraded template synthesis and hydrogel assembly followed by freeze-drying. The microstructure and composition of the materials are investigated by thermal gravimetric analysis, Raman spectrum, X-ray photoelectron spectroscopy, transmission electron microscopy, and specific surface analyzer. The results confirm the formation of three-dimensional carbon nanotube frameworks with low density, high mechanical properties, and high specific surface area. Compared with PPy aerogel precursor, the as-prepared three-dimensional carbon nanotube frameworks exhibit outstanding adsorption capacity towards organic dyes. Moreover, electrochemical tests show that the products possess high specific capacitance, good rate capability and excellent cycling performance with no capacitance loss over 1000 cycles. These characteristics collectively indicate the potential of three-dimensional polypyrrole-derived carbon nanotube framework as a promising macroscopic device for the applications in environmental and energy storages.

  10. New "sandwich" structures conformed from three dimensional

    Directory of Open Access Journals (Sweden)

    Alba, Juan J.

    1996-03-01

    Full Text Available Poor interlaminar properties as well as poor-skin-to-core adhesion properties are very often the common existing problems we find when designing with "sandwich" structures. A new type of 3D-fabric "sandwich" structure is being developed in order to avoid these problems. Although the manufacturing process is very simple, a very complex "sandwich" structure is obtained as a result of the complexity of the 3D-fabric used. This 3D-fabric is a 3D woven glass fabric produced on velvet weaving machines with glass yarns. It is an integrally woven "sandwich" laminate for all kinds of composite products. The strength of the vertical fibers makes, that also after impregnation with a resin matrix, the "sandwich" structure is maintained. The result is a laminate with high strength and stiffness and low weight. On each side of this "sandwich" laminate additional reinforcement materials can be laminated and a synthetic foam can be injected in the hollow structure. This will allow to establish the mechanical properties of a finished product.

    Las pobres propiedades, tanto interlaminares como de adhesión entre piel y núcleo, constituyen uno de los grandes problemas cuando se diseñan estructuras utilizando paneles tipo "sandwich". Un nuevo tipo de panel "sandwich", configurado a partir de tejidos tridimensionales, está siendo desarrollado en la actualidad con el objetivo de eliminar esos problemas. Aunque el proceso de fabricación es muy simple, el panel "sandwich" obtenido es de estructura compleja, como resultado de la complejidad del tejido tridimensional utilizado. Este tejido tridimensional (3D es un tejido de fibra de vidrio producido en máquinas de tejer especializadas. La resistencia de las fibras verticales hace que, después de la impregnación con una resina, se mantenga la configuración tipo "sandwich". El resultado es un laminado de alta resistencia, gran rigidez y bajo peso. Sobre cada uno de los lados del panel "sandwich" se pueden

  11. Path Planning in Three Dimensional Environment Using Feedback Linearization (Preprint)

    National Research Council Canada - National Science Library

    Schumacher, Corey J; Kanchanavally, Shreecharan; Ordonez, Raul

    2006-01-01

    This paper presents a control scheme via feedback linearization for three-dimensional cooperative path planning of a class of interconnected systems in general, and unmanned aerial vehicles (UAVs) in particular...

  12. Magnetic structure of two- and three-dimensional supramolecular compounds

    Energy Technology Data Exchange (ETDEWEB)

    Decurtins, S.; Schmalle, H.W.; Pellaux, R. [Zurich Univ. (Switzerland); Fischer, P.; Fauth, F. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ouladdiaf, B. [Institut Max von Laue - Paul Langevin, 75 - Paris (France)

    1997-09-01

    Supramolecular chiral networks of oxalato-bridged transition metals show either two- or three-dimensional structural features. The magnetic structures of such compounds have been investigated by means of elastic neutron powder diffraction. (author) 2 figs., 2 refs.

  13. Direct Linear Transformation Method for Three-Dimensional Cinematography

    Science.gov (United States)

    Shapiro, Robert

    1978-01-01

    The ability of Direct Linear Transformation Method for three-dimensional cinematography to locate points in space was shown to meet the accuracy requirements associated with research on human movement. (JD)

  14. Three dimensional QSAR: applications in pharmacology and toxicology

    National Research Council Canada - National Science Library

    Doucet, Jean-Pierre; Panaye, Annick

    2010-01-01

    ... networks and support vector machines. Three-Dimensional QSAR addresses the scope and limitations of different modeling techniques using case studies from pharmacology, toxicology, and ecotoxicology to demonstrate the utility of each...

  15. Three-dimensional anthropometry of the adult face.

    Science.gov (United States)

    1978-03-01

    This study describes a new three-dimensional anatomical axis system based on four conventional anthropometrical face landmarks. Coincident as a coordinate (orthogonal) axis system, this reference system was developed to provide convenient orientation...

  16. Three-dimensional reconstructions of solid surfaces using conventional microscopes.

    Science.gov (United States)

    Ficker, Tomáš; Martišek, Dalibor

    2016-01-01

    The three-dimensional digital replicas of solid surfaces are subject of interest of different branches of science and technology. The present paper in its introductory parts brings an overview of the various microscopic reconstructive techniques based on optical sectioning. The main attention is devoted to conventional reconstruction methods and especially to that one employing the Fourier transform. The three-dimensional replicas of this special reconstructive frequency method are compared graphically and numerically with the three-dimensional replicas of the confocal method. Based on the comparative study it has been concluded that the quality of the conventional replicas of surfaces possessing textures of intermediate height irregularities is acceptable and almost comparable with the quality of confocal replicas. This study is relevant both for identifying a convenient technique that provides good qualities of three-dimensional replicas and for selecting the hardware whose price is affordable even for small research groups studying rougher surface textures. © Wiley Periodicals, Inc.

  17. Utility of three-dimensional method for diagnosing meniscal lesions

    International Nuclear Information System (INIS)

    Ohshima, Suguru; Nomura, Kazutoshi; Hirano, Mako; Hashimoto, Noburo; Fukumoto, Tetsuya; Katahira, Kazuhiro

    1998-01-01

    MRI of the knee is a useful method for diagnosing meniscal tears. Although the spin echo method is usually used for diagnosing meniscal tears, we examined the utility of thin slice scan with the three-dimensional method. We reviewed 70 menisci in which arthroscopic findings were confirmed. In this series, sensitivity was 90.9% for medial meniscal injuries and 68.8% for lateral meniscal injuries. There were 3 meniscal tears in which we could not detect tears on preoperative MRI. We could find tears in two of these cases when re-evaluated using the same MRI. In conclusion, we can get the same diagnostic rate with the three-dimensional method compared with the spin echo method. Scan time of the three-dimensional method is 3 minutes, on the other hand that of spin echo method in 17 minutes. This slice scan with three-dimensional method is useful for screening meniscal injuries before arthroscopy. (author)

  18. Analysis and validation of carbohydrate three-dimensional structures

    International Nuclear Information System (INIS)

    Lütteke, Thomas

    2009-01-01

    The article summarizes the information that is gained from and the errors that are found in carbohydrate structures in the Protein Data Bank. Validation tools that can locate these errors are described. Knowledge of the three-dimensional structures of the carbohydrate molecules is indispensable for a full understanding of the molecular processes in which carbohydrates are involved, such as protein glycosylation or protein–carbohydrate interactions. The Protein Data Bank (PDB) is a valuable resource for three-dimensional structural information on glycoproteins and protein–carbohydrate complexes. Unfortunately, many carbohydrate moieties in the PDB contain inconsistencies or errors. This article gives an overview of the information that can be obtained from individual PDB entries and from statistical analyses of sets of three-dimensional structures, of typical problems that arise during the analysis of carbohydrate three-dimensional structures and of the validation tools that are currently available to scientists to evaluate the quality of these structures

  19. Analysis of three-dimensional transient seepage into ditch drains ...

    Indian Academy of Sciences (India)

    Ratan Sarmah

    dimensional solutions to the problem are actually valid not for a field of finite size but for an infinite one only. Keywords. Analytical models; three-dimensional ponded ditch drainage; transient seepage; variable ponding; hydraulic conductivity ...

  20. Creating physically-based three-dimensional microstructures: Bridging phase-field and crystal plasticity models.

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hojun [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Owen, Steven J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Abdeljawad, Fadi F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hanks, Byron [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Battaile, Corbett Chandler [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    In order to better incorporate microstructures in continuum scale models, we use a novel finite element (FE) meshing technique to generate three-dimensional polycrystalline aggregates from a phase field grain growth model of grain microstructures. The proposed meshing technique creates hexahedral FE meshes that capture smooth interfaces between adjacent grains. Three dimensional realizations of grain microstructures from the phase field model are used in crystal plasticity-finite element (CP-FE) simulations of polycrystalline a -iron. We show that the interface conformal meshes significantly reduce artificial stress localizations in voxelated meshes that exhibit the so-called "wedding cake" interfaces. This framework provides a direct link between two mesoscale models - phase field and crystal plasticity - and for the first time allows mechanics simulations of polycrystalline materials using three-dimensional hexahedral finite element meshes with realistic topological features.

  1. Simulation on three dimensional bubble formation using MARS

    International Nuclear Information System (INIS)

    Kunugi, Tomoaki

    1997-01-01

    This paper describes a numerical simulation on three-dimensional bubble formation by means of the MARS (Multi-interfaces Advection and Reconstruction Solver) developed by the author. The comparison between two-dimensional and three-dimensional simulation on an agglomeration of two bubbles is discussed. Moreover, some simulation results regarding a phase change phenomena such as a boiling and condensation in a two dimensional enclosure with heated and cooled walls are presented. (author)

  2. Computational study of three-dimensional wake structure

    International Nuclear Information System (INIS)

    Himeno, R.; Shirayama, S.; Kamo, K.; Kuwahara, K.

    1986-01-01

    Three-dimensional wake structure is studied by numerically solving the incompressible Navier-Stokes equations. Results are visualized by a three-dimensional color graphic system. It was found that a pair of vortex tubes separated from a body plays the most important role in the wake. Near the body vortex tubes are rather stable, however, they gradually become unsteady as they flow down

  3. Alignment-free three-dimensional optical metamaterials.

    Science.gov (United States)

    Zhao, Yang; Shi, Jinwei; Sun, Liuyang; Li, Xiaoqin; Alù, Andrea

    2014-03-05

    Three-dimensional optical metamaterials based on multilayers typically rely on critical vertical alignment to achieve the desired functionality. Here the conditions under which three-dimensional metamaterials with different functionalities may be realized without constraints on alignment are analyzed and demonstrated experimentally. This study demonstrates that the release of alignment constraints for multilayered metamaterials is allowed, while their anomalous interaction with light is preserved. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Three-dimensional study of the multi-cavity FEL

    Energy Technology Data Exchange (ETDEWEB)

    Krishnagopal, S.; Kumar, V. [Centre for Advanced Technology, Indore (India)

    1995-12-31

    The Multi-Cavity Free-Electron Laser has been proposed earlier, as a new configuration to obtain short, intense pulses of radiation, the key idea being to pre-bunch the electron beam in a number of very short cavities. Those studies were one-dimensional. Here we use three-dimensional simulations to study the viability of this concept when three-dimensional effects are included, particularly with regard to the transverse modes of the optical beam.

  5. Three-dimensional reconstruction of functional brain images

    International Nuclear Information System (INIS)

    Inoue, Masato; Shoji, Kazuhiko; Kojima, Hisayoshi; Hirano, Shigeru; Naito, Yasushi; Honjo, Iwao

    1999-01-01

    We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: routine images by SPM, three-dimensional static images, and three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the surface

  6. Discretization model for nonlinear dynamic analysis of three dimensional structures

    International Nuclear Information System (INIS)

    Hayashi, Y.

    1982-12-01

    A discretization model for nonlinear dynamic analysis of three dimensional structures is presented. The discretization is achieved through a three dimensional spring-mass system and the dynamic response obtained by direct integration of the equations of motion using central diferences. First the viability of the model is verified through the analysis of homogeneous linear structures and then its performance in the analysis of structures subjected to impulsive or impact loads, taking into account both geometrical and physical nonlinearities is evaluated. (Author) [pt

  7. Three-dimensional stellarator equilibrium as an ohmic steady state

    International Nuclear Information System (INIS)

    Park, W.; Monticello, D.A.; Strauss, H.; Manickam, J.

    1985-07-01

    A stable three-dimensional stellarator equilibrium can be obtained numerically by a time-dependent relaxation method using small values of dissipation. The final state is an ohmic steady state which approaches an ohmic equilibrium in the limit of small dissipation coefficients. We describe a method to speed up the relaxation process and a method to implement the B vector . del p = 0 condition. These methods are applied to obtain three-dimensional heliac equilibria using the reduced heliac equations

  8. Local nondestructive data reading in three-dimensional memory systems based on the optical Kerr effect

    International Nuclear Information System (INIS)

    Zheltikov, Aleksei M; Koroteev, Nikolai I; Naumov, A N; Fedotov, Andrei B; Magnitskiy, Sergey A; Sidorov-Biryukov, D A

    1998-01-01

    An investigation was made of the characteristics of the optical Kerr effect in a spiropyran solution. It was found that this effect makes it possible to distinguish the coloured and uncoloured forms of spiropyran and that it represents a promising method for nondestructive data reading in three-dimensional optical memory systems based on photochromic materials. (letters to the editor)

  9. Vascular fluorescence casting and imaging cryomicrotomy for computerized three-dimensional renal arterial reconstruction

    NARCIS (Netherlands)

    Lagerveld, Brunolf W.; ter Wee, Rene D.; de La Rosette, Jean J. M. C. H.; Spaan, Jos A. E.; Wijkstra, Hessel

    2007-01-01

    OBJECTIVES To assess the combined use of a casting technique, cryomicrotomy imaging, and three-dimensional (3D) computer analysis as a method for visualizing and reconstructing the arterial vascular tree in a porcine renal model. MATERIAL AND METHODS The arterial branches of two porcine kidneys were

  10. Potential Health and Environmental Risks of Three-Dimensional Engineered Polymers

    NARCIS (Netherlands)

    De Almeida Monteiro Melo Ferraz, Marcia; Henning, Heiko H.W.; Da Costa, Pedro Ferreira; Malda, Jos; Le Gac, Séverine; Bray, Fabrice; Van Duursen, Majorie B.M.; Brouwers, Jos F.; Van De Lest, Chris H.A.; Bertijn, Ingeborg; Kraneburg, Lisa; Vos, Peter L.A.M.; Stout, Tom A.E.; Gadella, Barend M.

    2018-01-01

    Polymer engineering, such as in three-dimensional (3D) printing, is rapidly gaining popularity, not only in the scientific and medical fields but also in the community in general. However, little is known about the toxicity of engineered materials. Therefore, we assessed the toxicity of 3D-printed

  11. Some Remarks on the Three Dimensionality of Hydrofoil Cavitation

    Directory of Open Access Journals (Sweden)

    Mehmet Salih KARAALİOĞLU

    2017-12-01

    Full Text Available As it is well-known that cavitation is a very important physical phenomenon that affects significantly the performance of three-dimensional hydrofoils. Prediction of cavitation on three-dimensional hydrofoils is very important in the design stage. In this study, some approaches have been verified for hydrofoil cavitation. The main aim of this paper is to compare the mid-section pressure distribution of three-dimensional cavitating rectangular hydrofoil for increasing aspect ratios, with the pressure distribution of two-dimensional cavitating hydrofoil having the same section geometry as in the three-dimensional hydrofoil. In this study, a boundary element (panel method (BEM has been applied to investigate the hydrofoil cavitation for both two- and three-dimensional cases. Two-dimensional analytical solution in case of cavitating flat-plate has also been applied for comparison. It has been shown that the pressure distributions on the mid-section of three-dimensional cavitating and non-cavitating hydrofoil for increasing aspect ratios have converged to the solutions in two-dimensional case.

  12. Three-Dimensional (3D) Additive Construction: Printing with Regolith

    Science.gov (United States)

    Tsoras, Alexandra

    2013-01-01

    Three dimensional (3D) printing is a new and booming topic in many realms of research and engineering technology. When it comes to space science and aerospace engineering, it can be useful in numerous ways. As humans travel deeper into space and farther from Earth, sending large quantities of needed supplies from Earth for a mission becomes astronomically expensive and less plausible. In order to reach further to new places, In Situ Resource Utilization (ISRU), a project that pushes for technologies to use materials already present in the destination's environment, is necessary. By using materials already available in space such as regolith from the Moon, Mars, or an asteroid's surface, fewer materials need to be brought into space on a launched vehicle. This allows a vehicle to be filled with more necessary supplies for a deep space mission that may not be found in space, like food and fuel. This project's main objective was to develop a 3D printer that uses regolith to "print" large structures, such as a dome, to be used as a heat shield upon a vehicle's reentry into the atmosphere or even a habitat. 3D printing is a growing technology that uses many different methods to mix, heat, and mold a material into a specific shape. In order to heat the regolith enough to stick together into a solid shape, it must be sintered at each layer of material that is laid. Sintering is a process that heats and compresses a powdered material until it fuses into a solid, which requires a lot of energy input. As an alternative, a polymer can be mixed with the regolith before or as it is sent to the 3D printer head to be placed in the specific shape. The addition of the polymer, which melts and binds at much lower temperatures than sintering temperatures, greatly decreases the required heating temperature and energy input. The main task of the project was to identify a functional material for the printer. The first step was to find a miscible. polymer/solvent solution. This solution

  13. Applicability of three-dimensional imaging techniques in fetal medicine

    Energy Technology Data Exchange (ETDEWEB)

    Werner Junior, Heron; Daltro, Pedro; Gasparetto, Emerson Leandro, E-mail: heronwerner@hotmail.com [Clinica de Diagnostico Por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Santos, Jorge Lopes dos; Belmonte, Simone; Ribeiro, Gerson [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil); Marchiori, Edson [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2016-09-15

    Objective: To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology. Materials and Methods: We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques. Results: Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations. Conclusion: The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models. (author)

  14. Three-Dimensional Reconstruction Optical System Using Shadows Triangulation

    Science.gov (United States)

    Barba, J. Leiner; Vargas, Q. Lorena; Torres, M. Cesar; Mattos, V. Lorenzo

    2008-04-01

    In this work is developed a three-dimensional reconstruction system using the Shades3D tool of the Matlab® Programming Language and materials of low cost, such as webcam camera, a stick, a weak structured lighting system composed by a desk lamp, and observation plane in which the object is located. The reconstruction is obtained through a triangulation process that is executed after acquiring a sequence of images of the scene with a shadow projected on the object; additionally an image filtering process is done for obtaining only the part of the scene that will be reconstructed. Previously, it is necessary to develop a calibration process for determining the internal camera geometric and optical characteristics (intrinsic parameters), and the 3D position and orientation of the camera frame relative to a certain world coordinate system (extrinsic parameters). The lamp and the stick are used to produce a shadow which scans the object; in this technique, it is not necessary to know the position of the light source, instead the triangulation is obtained using shadow plane produced by intersection between the stick and the illumination pattern. The webcam camera captures all images with the shadow scanning the object, and Shades3D tool processes all information taking into account captured images and calibration parameters. Likewise, this technique is evaluated in the reconstruction of parts of the human body and its application in the detection of external abnormalities and elaboration of prosthesis or implant.

  15. Three-dimensional (3D) MRI of the knee

    International Nuclear Information System (INIS)

    Shahabpour, M.; Spruyt, D.; Leroux, G.B.; Osteaux, M.

    1993-01-01

    Three-dimensional gradient echo T2-weighted sequences have a number of advantages over spin echo T2-weighted sequences (or even 2D gradient echo T2-weighted sequences) for assessment of the knee. They allow a multidimensional analysis based on a single acquisition sequence usually obtained in the sagittal plane. Image reconstructions can be performed secondarily in the coronal, axial and oblique planes, particularly along the specific path of the anterior cruciate ligament. By providing ultrathin serial sections, decreasing the partial volume effect, small lesions, such as cartilaginous fissures or flaps and radial meniscal lesions can be detected in the axial plane, for example. This advantage, combined with the marked sensitivity of gradient echo sequences to alterations in the tissue water content, allows the detection of partial tendon ruptures. The reduction of the partial volume effect and chemical shift artefact probably participate in the capacity of these sequences to visualize the two surfaces of the cartilage of the femorotibial joint. Flow artefacts are less of a problem than with 2D imaging, which eliminates the need for techniques such as saturation of the vascular signal or cardiac gating. A disadvantage of these gradient echo sequences (3D or 2D) is their sensitivity to the presence of metallic material, limiting their application in operated knees

  16. Three-dimensional Monte Carlo calculation of some nuclear parameters

    Science.gov (United States)

    Günay, Mehtap; Şeker, Gökmen

    2017-09-01

    In this study, a fusion-fission hybrid reactor system was designed by using 9Cr2WVTa Ferritic steel structural material and the molten salt-heavy metal mixtures 99-95% Li20Sn80 + 1-5% RG-Pu, 99-95% Li20Sn80 + 1-5% RG-PuF4, and 99-95% Li20Sn80 + 1-5% RG-PuO2, as fluids. The fluids were used in the liquid first wall, blanket and shield zones of a fusion-fission hybrid reactor system. Beryllium (Be) zone with the width of 3 cm was used for the neutron multiplication between the liquid first wall and blanket. This study analyzes the nuclear parameters such as tritium breeding ratio (TBR), energy multiplication factor (M), heat deposition rate, fission reaction rate in liquid first wall, blanket and shield zones and investigates effects of reactor grade Pu content in the designed system on these nuclear parameters. Three-dimensional analyses were performed by using the Monte Carlo code MCNPX-2.7.0 and nuclear data library ENDF/B-VII.0.

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

    Science.gov (United States)

    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.

  18. Self-assembled three dimensional network designs for soft electronics.

    Science.gov (United States)

    Jang, Kyung-In; Li, Kan; Chung, Ha Uk; Xu, Sheng; Jung, Han Na; Yang, Yiyuan; Kwak, Jean Won; Jung, Han Hee; Song, Juwon; Yang, Ce; Wang, Ao; Liu, Zhuangjian; Lee, Jong Yoon; Kim, Bong Hoon; Kim, Jae-Hwan; Lee, Jungyup; Yu, Yongjoon; Kim, Bum Jun; Jang, Hokyung; Yu, Ki Jun; Kim, Jeonghyun; Lee, Jung Woo; Jeong, Jae-Woong; Song, Young Min; Huang, Yonggang; Zhang, Yihui; Rogers, John A

    2017-06-21

    Low modulus, compliant systems of sensors, circuits and radios designed to intimately interface with the soft tissues of the human body are of growing interest, due to their emerging applications in continuous, clinical-quality health monitors and advanced, bioelectronic therapeutics. Although recent research establishes various materials and mechanics concepts for such technologies, all existing approaches involve simple, two-dimensional (2D) layouts in the constituent micro-components and interconnects. Here we introduce concepts in three-dimensional (3D) architectures that bypass important engineering constraints and performance limitations set by traditional, 2D designs. Specifically, open-mesh, 3D interconnect networks of helical microcoils formed by deterministic compressive buckling establish the basis for systems that can offer exceptional low modulus, elastic mechanics, in compact geometries, with active components and sophisticated levels of functionality. Coupled mechanical and electrical design approaches enable layout optimization, assembly processes and encapsulation schemes to yield 3D configurations that satisfy requirements in demanding, complex systems, such as wireless, skin-compatible electronic sensors.

  19. Three-dimensional spiral CT of craniofacial malformations in children

    International Nuclear Information System (INIS)

    Binaghi, S.; Gudinchet, F.

    2000-01-01

    Objective. To assess the value of three-dimensional CT (3D CT) in the diagnosis and management of suspected paediatric craniofacial malformations. Materials and methods. Twenty-eight children (12 girls, 16 boys) with a mean age of 4 years, suffering from craniofacial or cervical malformations, underwent craniofacial spiral CT. 3D reformatting was performed using an independent workstation. Results. 3D CT allowed the preoperative evaluation of 16 patients with craniosynostosis and the post-surgical management of 2 patients. 3D CT clearly depicted malformations of the skull base involving the petrous bone in seven patients (four cases of Goldenhar-Gorlin syndrome, one case of Treacher-Collins syndrome and two cases of Crouzon's disease). Four patients with craniofacial clefts were also evaluated. Radiological findings were confirmed by the clinical and intraoperative findings in all patients that underwent surgical treatment. Movement artefacts and ''Lego effect'' related to abrupt change of cranial vault border were encountered and are discussed. Conclusions. 3D CT of the skull can safely and reliably identify paediatric craniofacial malformations involving bone, and it should be used as morphological mapping to help the surgeon in planning surgical treatment. (orig.)

  20. Instrumented cardiac microphysiological devices via multimaterial three-dimensional printing

    Science.gov (United States)

    Lind, Johan U.; Busbee, Travis A.; Valentine, Alexander D.; Pasqualini, Francesco S.; Yuan, Hongyan; Yadid, Moran; Park, Sung-Jin; Kotikian, Arda; Nesmith, Alexander P.; Campbell, Patrick H.; Vlassak, Joost J.; Lewis, Jennifer A.; Parker, Kevin K.

    2017-03-01

    Biomedical research has relied on animal studies and conventional cell cultures for decades. Recently, microphysiological systems (MPS), also known as organs-on-chips, that recapitulate the structure and function of native tissues in vitro, have emerged as a promising alternative. However, current MPS typically lack integrated sensors and their fabrication requires multi-step lithographic processes. Here, we introduce a facile route for fabricating a new class of instrumented cardiac microphysiological devices via multimaterial three-dimensional (3D) printing. Specifically, we designed six functional inks, based on piezo-resistive, high-conductance, and biocompatible soft materials that enable integration of soft strain gauge sensors within micro-architectures that guide the self-assembly of physio-mimetic laminar cardiac tissues. We validated that these embedded sensors provide non-invasive, electronic readouts of tissue contractile stresses inside cell incubator environments. We further applied these devices to study drug responses, as well as the contractile development of human stem cell-derived laminar cardiac tissues over four weeks.

  1. Three-dimensional cell culture technique and pathophysiology.

    Science.gov (United States)

    Matsusaki, Michiya; Case, Charles Patrick; Akashi, Mitsuru

    2014-07-01

    Three-dimensional (3D) tissue constructs consisting of human cells have opened a new avenue for tissue engineering, pharmaceutical and pathophysiological applications, and have great potential to estimate the dynamic pharmacological effects of drug candidates, metastasis processes of cancer cells, and toxicity expression of nano-materials, as a 3D-human tissue model instead of in vivo animal experiments. However, most 3D-cellular constructs are a cell spheroid, which is a heterogeneous aggregation, and thus the reconstruction of the delicate and precise 3D-location of multiple types of cells is almost impossible. In recent years, various novel technologies to develop complex 3D-human tissues including blood and lymph capillary networks have demonstrated that physiological human tissue responses can be replicated in the nano/micro-meter ranges. Here, we provide a brief overview on current 3D-tissue fabrication technologies and their biomedical applications. 3D-human tissue models will be a powerful technique for pathophysiological applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Self-assembled three dimensional network designs for soft electronics

    Science.gov (United States)

    Jang, Kyung-In; Li, Kan; Chung, Ha Uk; Xu, Sheng; Jung, Han Na; Yang, Yiyuan; Kwak, Jean Won; Jung, Han Hee; Song, Juwon; Yang, Ce; Wang, Ao; Liu, Zhuangjian; Lee, Jong Yoon; Kim, Bong Hoon; Kim, Jae-Hwan; Lee, Jungyup; Yu, Yongjoon; Kim, Bum Jun; Jang, Hokyung; Yu, Ki Jun; Kim, Jeonghyun; Lee, Jung Woo; Jeong, Jae-Woong; Song, Young Min; Huang, Yonggang; Zhang, Yihui; Rogers, John A.

    2017-06-01

    Low modulus, compliant systems of sensors, circuits and radios designed to intimately interface with the soft tissues of the human body are of growing interest, due to their emerging applications in continuous, clinical-quality health monitors and advanced, bioelectronic therapeutics. Although recent research establishes various materials and mechanics concepts for such technologies, all existing approaches involve simple, two-dimensional (2D) layouts in the constituent micro-components and interconnects. Here we introduce concepts in three-dimensional (3D) architectures that bypass important engineering constraints and performance limitations set by traditional, 2D designs. Specifically, open-mesh, 3D interconnect networks of helical microcoils formed by deterministic compressive buckling establish the basis for systems that can offer exceptional low modulus, elastic mechanics, in compact geometries, with active components and sophisticated levels of functionality. Coupled mechanical and electrical design approaches enable layout optimization, assembly processes and encapsulation schemes to yield 3D configurations that satisfy requirements in demanding, complex systems, such as wireless, skin-compatible electronic sensors.

  3. Psychological Science within a Three-Dimensional Ontology.

    Science.gov (United States)

    Lundh, Lars-Gunnar

    2018-03-01

    The present paper outlines the nature of a three-dimensional ontology and the place of psychological science within this ontology, in a way that is partly similar to and partly different from that of Pérez-Álvarez. The first dimension is the material realities, and involves different levels (physical, chemical, biological, psychological, etc.), where each level builds on a lower level but also involves the development of new emergent properties, in accordance with Bunge's emergent materialism. Each level involves systems, with components, structures and mechanisms, and an environment. This dimension can be studied with natural scientific methods. The second dimension is the subjective-experiential realities, and refers to our subjective perspective on the world. In accordance with Husserl's phenomenology, it is argued that this subjectivity does not exist in the world (i.e., should not be reified as an object among other objects), but represents a perspective on the world that we enter in our capacity as conscious human beings. Essential characteristics of this subjectivity (such as intentionality, temporality, embodiment, and intersubjectivity) can be explored by phenomenological methods. The third dimension is the social-constructional realities, and includes social institutions, norms, categories, theories, and techniques. It is argued that psychological science spans over all three dimensions. Although almost all psychological research by necessity starts from a problem formulation where the subjective-experiential dimension plays an essential role (either explicitly or implicitly), most of present-day psychological research clearly emphasizes the material dimension. It is argued that a mature psychological science needs to integrate all three dimensions.

  4. The listening cube: a three dimensional auditory training program.

    Science.gov (United States)

    De Raeve, Leo; Leo, De Raeve; Anderson, Ilona; Ilona, Anderson; Bammens, Marleen; Marleen, Bammens; Jans, Josepha; Josepha, Jans; Haesevoets, Marianne; Marianne, Haesevoets; Pans, Ria; Ria, Pans; Vandistel, Hilde; Hilde, Vandistel; Vrolix, Yvette; Yvette, Vrolix

    2012-04-01

    Here we present the Listening Cube, an auditory training program for children and adults receiving cochlear implants, developed during the clinical practice at the KIDS Royal Institute for the Deaf in Belgium. We provide information on the content of the program as well as guidance as to how to use it. The Listening Cube is a three-dimensional auditory training model that takes the following into consideration: the sequence of auditory listening skills to be trained, the variety of materials to be used, and the range of listening environments to be considered. During auditory therapy, it is important to develop training protocols and materials to provide rapid improvement over a relatively short time period. Moreover, effectiveness and the general real-life applicability of these protocols to various users should be determined. Because this publication is not a research article, but comes out of good daily practice, we cannot state the main results of this study. We can only say that this auditory training model is very successful. Since the first report was published in the Dutch language in 2003, more than 200 therapists in Belgium and the Netherlands followed a training course elected to implement the Listening Cube in their daily practice with children and adults with a hearing loss, especially in those wearing cochlear implants. The Listening Cube is a tool to aid in planning therapeutic sessions created to meet individual needs, which is often challenging. The three dimensions of the cube are levels of perception, practice material, and practice conditions. These dimensions can serve as a visual reminder of the task analysis and of other considerations that play a role in structuring therapy sessions.

  5. Visual Interpretation with Three-Dimensional Annotations (VITA): Three-Dimensional Image Interpretation Tool for Radiological Reporting

    OpenAIRE

    Roy, Sharmili; Brown, Michael S.; Shih, George L.

    2013-01-01

    This paper introduces a software framework called Visual Interpretation with Three-Dimensional Annotations (VITA) that is able to automatically generate three-dimensional (3D) visual summaries based on radiological annotations made during routine exam reporting. VITA summaries are in the form of rotating 3D volumes where radiological annotations are highlighted to place important clinical observations into a 3D context. The rendered volume is produced as a Digital Imaging and Communications i...

  6. Three-Dimensional Modeling of Fracture Clusters in Geothermal Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Ghassemi, Ahmad [Univ. of Oklahoma, Norman, OK (United States)

    2017-08-11

    The objective of this is to develop a 3-D numerical model for simulating mode I, II, and III (tensile, shear, and out-of-plane) propagation of multiple fractures and fracture clusters to accurately predict geothermal reservoir stimulation using the virtual multi-dimensional internal bond (VMIB). Effective development of enhanced geothermal systems can significantly benefit from improved modeling of hydraulic fracturing. In geothermal reservoirs, where the temperature can reach or exceed 350oC, thermal and poro-mechanical processes play an important role in fracture initiation and propagation. In this project hydraulic fracturing of hot subsurface rock mass will be numerically modeled by extending the virtual multiple internal bond theory and implementing it in a finite element code, WARP3D, a three-dimensional finite element code for solid mechanics. The new constitutive model along with the poro-thermoelastic computational algorithms will allow modeling the initiation and propagation of clusters of fractures, and extension of pre-existing fractures. The work will enable the industry to realistically model stimulation of geothermal reservoirs. The project addresses the Geothermal Technologies Office objective of accurately predicting geothermal reservoir stimulation (GTO technology priority item). The project goal will be attained by: (i) development of the VMIB method for application to 3D analysis of fracture clusters; (ii) development of poro- and thermoelastic material sub-routines for use in 3D finite element code WARP3D; (iii) implementation of VMIB and the new material routines in WARP3D to enable simulation of clusters of fractures while accounting for the effects of the pore pressure, thermal stress and inelastic deformation; (iv) simulation of 3D fracture propagation and coalescence and formation of clusters, and comparison with laboratory compression tests; and (v) application of the model to interpretation of injection experiments (planned by our

  7. Radiation Dosimetry Using Three-Dimensional Optical Random Access Memories

    International Nuclear Information System (INIS)

    Moscovitch, M.

    2001-01-01

    The ability to determine particle type and energy plays an important role in the dosimetry of heavy charged particles (HCP) and neutrons. A new approach to radiation dosimetry is presented, which is shown to be capable of particle type and energy discrimination. This method is based on utilizing radiation induced changes in the digital information stored on three-dimensional optical random access memories (3D ORAM). 3D ORAM is a small cube (a few mm 3 ) composed of poly(methyl methacrylate) doped with a photochromic dye, and it was originally proposed as a memory device in high speed parallel computers. A Nd:YAG laser system is used to write and read binary information (bits) on the ORAM, which functions as a charged particle detector. Both the read and the write processes use two laser beams that simultaneously strike the material to cause a color change at their intersection (similar to the darkening of light-sensitive sunglasses when exposed to sunlight.) The laser produces color changes in the ORAM, which then reverts to the original color (''bit-flips'') at sites where energy is deposited from interaction with incident HCP or neutron-recoil protons. The feasibility of this approach was demonstrated both theoretically and experimentally. Calculations based on track structure theory (TST) predict that when HCP interact with the ORAM material, the local energy deposition is capable of inducing measurable ''bit-flips''. These predictions were recently confirmed experimentally using two types of ORAM systems, one based on spirobenzopyran and the other on anthracene, as the photochromic dyes

  8. Radiation dosimetry using three-dimensional optical random access memories

    International Nuclear Information System (INIS)

    Moscovitch, M.; Phillips, G.W.; Cullum, B.M.; Mobley, J.; Bogard, J.S.; Emfietzoglou, D.; Vo-Dinh, T.

    2002-01-01

    The ability to determine particle type and energy plays an important role in the dosimetry of heavy charged particles (HCP) and neutrons. A new approach to radiation dosimetry is presented, which is shown to be capable of particle type and energy discrimination. This method is based on utilising radiation induced changes in the digital information stored on three-dimensional optical random access memories (3D ORAM). 3D ORAM is a small cube (a few mm 3 ) composed of poly(methyl methacrylate) doped with a photochromic dye, and it was originally proposed as a memory device in high speed parallel computers. A Nd:YAG laser system is used to write and read binary information (bits) on the ORAM, which functions as a charged particle detector. Both the read and the write processes use two laser beams that simultaneously strike the material to cause a colour change at their intersection (similar to the darkening of light-sensitive sunglasses when exposed to sunlight). The laser produces colour changes in the ORAM, which then reverts to the original colour ('bit-flips') at sites where energy is deposited from interaction with incident HCP or neutron-recoil protons. The feasibility of this approach was demonstrated both theoretically and experimentally. Calculations based on track structure theory predict that when HCP interact with the ORAM material, the local energy deposition is capable of inducing measurable 'bit-flips'. These predictions were recently confirmed experimentally using two types of ORAM systems, one based on spirobenzopyran and the other on anthracene, as the photochromic dyes. (author)

  9. Robot vision based on three-dimensional model

    International Nuclear Information System (INIS)

    Shirai, Yoshiaki

    1985-01-01

    In order that robots recognize objects, the models of the objects are required. If there is not any constraint about an object scene, it is desirable that robot vision has the three-dimensional models of the things composing the scene. Since the preparation of three-dimensional models takes much time, here, the utilization of the geometrical models made by CAD is proposed. Besides, when the description of a scene and three-dimensional models are compared, to attempt the comparison with all attitudes of respective models is not efficient, therefore, stratum-wise comparison was proposed. As concrete examples, when input information is only in the direction of a part of surfaces such as lustrous bodies, when information can be obtained in all the directions of the surfaces of a body visible by a photometric stereo, and when complete three dimensional information is obtained by a distance-measuring instrument, the techniques of object recognition are described. In all cases, by carrying out the stratum-wise comparison based on three-dimensional models, the efficient and generalized object recognition was able to be achieved. (Kako, I.)

  10. A plastic surgery application in evolution: three-dimensional printing.

    Science.gov (United States)

    Gerstle, Theodore L; Ibrahim, Ahmed M S; Kim, Peter S; Lee, Bernard T; Lin, Samuel J

    2014-02-01

    Three-dimensional printing represents an evolving technology still in its infancy. Currently, individuals and small business entities have the ability to manufacture physical objects from digital renderings, computer-aided design, and open source files. Design modifications and improvements in extrusion methods have made this technology much more affordable. This article explores the potential uses of three-dimensional printing in plastic surgery. A review was performed detailing the known uses of three-dimensional printing in medicine. The potential applications of three-dimensional printing in plastic surgery are discussed. Various applications for three-dimensional printing technology have emerged in medicine, including printing organs, printing body parts, bio-printing, and computer-aided tissue engineering. In plastic surgery, these tools offer various prospective applications for surgical planning, resident education, and the development of custom prosthetics. Numerous applications exist in medicine, including the printing of devices, implants, tissue replacements, and even whole organs. Plastic surgeons may likely find this technology indispensable in surgical planning, education, and prosthetic device design and development in the near future.

  11. Three-dimensional magnetospheric equilibrium with isotropic pressure

    International Nuclear Information System (INIS)

    Cheng, C.Z.

    1995-05-01

    In the absence of the toroidal flux, two coupled quasi two-dimensional elliptic equilibrium equations have been derived to describe self-consistent three-dimensional static magnetospheric equilibria with isotropic pressure in an optimal (Ψ,α,χ) flux coordinate system, where Ψ is the magnetic flux function, χ is a generalized poloidal angle, α is the toroidal angle, α = φ - δ(Ψ,φ,χ) is the toroidal angle, δ(Ψ,φ,χ) is periodic in φ, and the magnetic field is represented as rvec B = ∇Ψ x ∇α. A three-dimensional magnetospheric equilibrium code, the MAG-3D code, has been developed by employing an iterative metric method. The main difference between the three-dimensional and the two-dimensional axisymmetric solutions is that the field-aligned current and the toroidal magnetic field are finite for the three-dimensional case, but vanish for the two-dimensional axisymmetric case. With the same boundary flux surface shape, the two-dimensional axisymmetric results are similar to the three-dimensional magnetosphere at each local time cross section

  12. Three-dimensional imaging of rheumatoid hands with MR

    International Nuclear Information System (INIS)

    Phillips, J.J.; Fischer, H.; Hollister, A.; Myers, L.

    1990-01-01

    Quantitative evaluation of soft-tissue proliferation associated with rheumatoid disease provided an objective measure of the activity and pattern of joint pathology. This paper propose a three-dimensional model for this purpose. With use of a 1.5-T Picker MR imager and a stellar GS 2000 computer graphics workstation, hands from patients with rheumatoid arthritis and age-matched controls were imaged to measure the quantity and location of inflammatory tissues. Three-dimensional Fourier transform gradient-echo sequences were used, with 0.8-1.6-mm section thickness. The definition of soft-tissue abnormalities and normal structures was facilitated by image smoothing and edge-detection computer algorithms. Separation of joint components permitted volume measurements and three-dimensional graphic displays

  13. On three-dimensional quiver gauge theories of type B

    Science.gov (United States)

    Dey, Anindya; Hanany, Amihay; Koroteev, Peter; Mekareeya, Noppadol

    2017-09-01

    We study three-dimensional supersymmetric quiver gauge theories with a nonsimply laced global symmetry primarily focusing on framed affine B N quiver theories. Using a supersymmetric partition function on a three sphere, and its transformation under S-duality, we study the three-dimensional ADHM quiver for SO(2 N + 1) instantons with a half-integer Chern-Simons coupling. The theory after S-duality has no Lagrangian, and can not be represented by a single quiver, however its partition function can be conveniently described by a collection of framed affine B N quivers. This correspondence can be conjectured to generalize three-dimensional mirror symmetry to theories with nontrivial Chern-Simons terms. In addition, we propose a formula for the superconformal index of a theory described by a framed affine B N quiver.

  14. Three-dimensional particle image velocimetry measurement technique

    International Nuclear Information System (INIS)

    Hassan, Y.A.; Seeley, C.H.; Henderson, J.A.; Schmidl, W.D.

    2004-01-01

    The experimental flow visualization tool, Particle Image Velocimetry (PIV), is being used to determine the velocity field in two-dimensional fluid flows. In the past few years, the technique has been improved to allow the capture of flow fields in three dimensions. This paper describes changes which were made to two existing two-dimensional tracking algorithms to enable them to track three-dimensional PIV data. Results of the tests performed on these three-dimensional routines with synthetic data are presented. Experimental data was also used to test the tracking algorithms. The test setup which was used to acquire the three-dimensional experimental data is described, along with the results from both of the tracking routines which were used to analyze the experimental data. (author)

  15. Eustachian tube three-dimensional reconstruction of secretory otitis media

    International Nuclear Information System (INIS)

    Yu Yafeng; Zhou Weirong; Bao Xueping; Li Min; Hu Zhenmin

    2006-01-01

    Objective: To study relationship between Eustachian tube and secretory otitis media and to explore the pathogeny of secretory otitis by three-dimensional reconstruction of Eustachian tube. Methods: Thirty cases of secretory otitis media (male 19, female 11) were selected randomly. Everyone was checked by otoscope and audiometry. Their bilateral Eustachian tubes were scanning by helix CT while making Valsalva's action. All images were passed on to work station to make three-dimensional reconstruction. Results: Four patients were found have Eustachian tube diseases, while most of patients' Eustachian tubes ventilated normally. Conclusions: Three-dimensional reconstruction of Eustachian tube can open out some pathogens of some secretory otitis medias. It will be helpful to diagnosis and therapy of secretory otitis media. (authors)

  16. Computational methods for three-dimensional microscopy reconstruction

    CERN Document Server

    Frank, Joachim

    2014-01-01

    Approaches to the recovery of three-dimensional information on a biological object, which are often formulated or implemented initially in an intuitive way, are concisely described here based on physical models of the object and the image-formation process. Both three-dimensional electron microscopy and X-ray tomography can be captured in the same mathematical framework, leading to closely-related computational approaches, but the methodologies differ in detail and hence pose different challenges. The editors of this volume, Gabor T. Herman and Joachim Frank, are experts in the respective methodologies and present research at the forefront of biological imaging and structural biology.   Computational Methods for Three-Dimensional Microscopy Reconstruction will serve as a useful resource for scholars interested in the development of computational methods for structural biology and cell biology, particularly in the area of 3D imaging and modeling.

  17. Three-dimensional, three-component wall-PIV

    Science.gov (United States)

    Berthe, André; Kondermann, Daniel; Christensen, Carolyn; Goubergrits, Leonid; Garbe, Christoph; Affeld, Klaus; Kertzscher, Ulrich

    2010-06-01

    This paper describes a new time-resolved three-dimensional, three-component (3D-3C) measurement technique called wall-PIV. It was developed to assess near wall flow fields and shear rates near non-planar surfaces. The method is based on light absorption according to Beer-Lambert’s law. The fluid containing a molecular dye and seeded with buoyant particles is illuminated by a monochromatic, diffuse light. Due to the dye, the depth of view is limited to the near wall layer. The three-dimensional particle positions can be reconstructed by the intensities of the particle’s projection on an image sensor. The flow estimation is performed by a new algorithm, based on learned particle trajectories. Possible sources of measurement errors related to the wall-PIV technique are analyzed. The accuracy analysis was based on single particle experiments and a three-dimensional artificial data set simulating a rotating sphere.

  18. Time-of-Flight Three Dimensional Neutron Diffraction in Transmission Mode for Mapping Crystal Grain Structures

    OpenAIRE

    Cereser, Alberto; Strobl, Markus; Hall, Stephen; Steuwer, Axel; Kiyanagi, Ryoji; Tremsin, Anton; Knudsen, Erik Bergbäck; Shinohara, Takenao; Willendrup, Peter; Fanta, Alice Bastos da Silva; Iyengar, Srinivasan; Larsen, Peter Mahler; Hanashima, Takayasu; Moyoshi, Taketo; Kadletz, Peter M.

    2017-01-01

    The physical properties of polycrystalline materials depend on their microstructure, which is the nano- to centimeter scale arrangement of phases and defects in their interior. Such microstructure depends on the shape, crystallographic phase and orientation, and interfacing of the grains constituting the material. This article presents a new non-destructive 3D technique to study centimeter-sized bulk samples with a spatial resolution of hundred micrometers: time-of-flight three-dimensional ne...

  19. Three Dimensional Analysis of Elastic Rocket and Launcher at Launching

    Science.gov (United States)

    Takeuchi, Shinsuke

    In this paper, a three-dimensional analysis of launching dynamics of a sounding rocket is investigated. In the analysis, the elastic vibration of the vehicle and launcher is considered. To estimate a trajectory dispersion including the effect of elasticity of the vehicle and launcher, a three-dimensional numerical simulation of a launch is performed. The accuracy of the numerical simulation is discussed and it is concluded that the simulation can estimate the maximum value of the trajectory dispersion properly. After that, the maximum value is estimated for the actual sounding rocket and the value is shown to be within the safty margin for this particular case.

  20. Three-dimensional Reciprocal Structures: Morphology, Concepts, Generative Rules

    DEFF Research Database (Denmark)

    Parigi, Dario; Pugnale, Alberto

    2012-01-01

    This paper present seven different three dimensional structures based on the principle of structural reciprocity with superimposition joint and standardized un-notched elements. Such typology could be regarded as being intrinsically three-dimensional because elements sit one of the top of the oth......, causing every configuration to develop naturally out-of the plane. The structures presented here were developed and built by the students of the Master of Science in “Architectural Design” during a two week long workshop organized at Aalborg University in the fall semester 2011....

  1. Three-dimensional induced polarization data inversion for complex resistivity

    Energy Technology Data Exchange (ETDEWEB)

    Commer, M.; Newman, G.A.; Williams, K.H.; Hubbard, S.S.

    2011-03-15

    The conductive and capacitive material properties of the subsurface can be quantified through the frequency-dependent complex resistivity. However, the routine three-dimensional (3D) interpretation of voluminous induced polarization (IP) data sets still poses a challenge due to large computational demands and solution nonuniqueness. We have developed a flexible methodology for 3D (spectral) IP data inversion. Our inversion algorithm is adapted from a frequency-domain electromagnetic (EM) inversion method primarily developed for large-scale hydrocarbon and geothermal energy exploration purposes. The method has proven to be efficient by implementing the nonlinear conjugate gradient method with hierarchical parallelism and by using an optimal finite-difference forward modeling mesh design scheme. The method allows for a large range of survey scales, providing a tool for both exploration and environmental applications. We experimented with an image focusing technique to improve the poor depth resolution of surface data sets with small survey spreads. The algorithm's underlying forward modeling operator properly accounts for EM coupling effects; thus, traditionally used EM coupling correction procedures are not needed. The methodology was applied to both synthetic and field data. We tested the benefit of directly inverting EM coupling contaminated data using a synthetic large-scale exploration data set. Afterward, we further tested the monitoring capability of our method by inverting time-lapse data from an environmental remediation experiment near Rifle, Colorado. Similar trends observed in both our solution and another 2D inversion were in accordance with previous findings about the IP effects due to subsurface microbial activity.

  2. Three-Dimensional Seismic Tomography Beneath Tangshan, China

    Science.gov (United States)

    Chang, J. C.; Keranen, K. M.; Keller, G.; Qu, G.; Harder, S. H.

    2010-12-01

    The 1976 earthquake in Tangshan, China ranks as the deadliest earthquake in modern times. Though the exact number of casualties remains disputed, it is widely accepted that at least a quarter of a million people died. The high casualty level is surprising since the earthquake was not unusually large (Mw 7.5). Amplification of ground motion by thick sediment fill in the basin underlying the city is a likely cause for the extensive destruction. However, the extent of the unconsolidated material and the broader subsurface geology beneath Tangshan and surrounding areas needs to be better-constrained to properly model predicted ground motion and mitigate the hazards of future earthquakes. From a broader perspective, the Tangshan area is at the northern edge of the Bohai Bay basin province that has experienced both Cenozoic extension and related strike-slip tectonism. In January 2010, our group conducted a three-dimensional seismic investigation centered on the city of Tangshan. In an area of approximately 40 km x 60 km, we deployed 500 REFTEK 125A (“Texan”) recorders at 500 m spacing. A number of different sources, 20 altogether, were recorded during the two-day listening window, which include our large shots, smaller explosive shots from a co-spatial reflection survey, blasts from nearby quarries, and a small (Mearthquake. Our preliminary analyses suggest that the sediment fill is, on average, less than 1 km thick. Sediment fill is thinner to the north, as evidenced by outcropping bedrock, and thickens to the south. Sediment seismic velocity is about 1.8 km/s. Upper crustal velocities are 5.2 to 6.6 km/s, and increase to 7.0 km/s at mid-crustal depths.

  3. Potential of the LTCC for unconventional three-dimensional applications

    OpenAIRE

    Slosarčík, S.; Banský, J.; Urbančík, J.; Vehec, I.; Kardoš, S.

    2006-01-01

    Описано потенційно можливе застосування матеріалів на основі низькотемпературної кераміки. Основну увагу звернуто на тривимірні (3D) електронні модулі, їхні механічні властивості і їхній можливий вплив на якість і надійність кінцевого продукту. This paper describes one of the utilization possibilities, which is given by the potential of the LTCC materials. The accent was oriented to the three-dimensional (3D) electronic modules, their mechanical properties and their possible influence to the ...

  4. Visualization of three dimensional earth fissures in geological structure

    Directory of Open Access Journals (Sweden)

    L. Zhu

    2015-11-01

    Full Text Available This paper proposes a new method for visualizing the earth fissures of geological structure in three dimensional (3-D domains on the basis of the seismic data and features information of earth fissures. The seismic data were interpreted for obtaining the stratagraphic data with various lithological information and the depth of the earth fissures. The spatial distribution of the ground fissures including the dip, strike and width were digitalized on an ArcGIS platform. Firstly, the 3-D geological structure was rebuilt using the Generalized Tri-Prism (GTP method which is a real solid method for displaying geological structures. The GTP method can reflect the inner material of the strata and can simulate complicated geological structures such as faults and stratagraphic pinch outs. The upper and lower surfaces of each stratum consist of Triangle Irregular Networks (TIN. The inner solid between the two surfaces are a series of triangular prisms. Secondly, since the width of the ground fissure gradually decreases with depth, multiple edge lines of the earth fissures on the bottom stratum surface are deduced on the basis of the fissure characteristics. Then, the model of the earth fissures consisting of a series of triangular pyramids can be constructed using these points and the edge lines. A cutting operation was carried out on the 3-D geological structure using this ground fissures model. If the surfaces of the ground fissures model intersects with the GTPs in the geological structure model, new GTPs were generated within the local regions. During this process, the topological relations between TIN, triangular prism and lines were reconstructed so that the visualization of ground fissures in the geological structure model is realized. This method can facilitate the mechanism for studying fissures and avoid the gaps between the fissure solid and the geological structure to accurately reflect their 3-D characteristics.

  5. Three-Dimensional Printing Based Hybrid Manufacturing of Microfluidic Devices.

    Science.gov (United States)

    Alapan, Yunus; Hasan, Muhammad Noman; Shen, Richang; Gurkan, Umut A

    2015-05-01

    Microfluidic platforms offer revolutionary and practical solutions to challenging problems in biology and medicine. Even though traditional micro/nanofabrication technologies expedited the emergence of the microfluidics field, recent advances in advanced additive manufacturing hold significant potential for single-step, stand-alone microfluidic device fabrication. One such technology, which holds a significant promise for next generation microsystem fabrication is three-dimensional (3D) printing. Presently, building 3D printed stand-alone microfluidic devices with fully embedded microchannels for applications in biology and medicine has the following challenges: (i) limitations in achievable design complexity, (ii) need for a wider variety of transparent materials, (iii) limited z-resolution, (iv) absence of extremely smooth surface finish, and (v) limitations in precision fabrication of hollow and void sections with extremely high surface area to volume ratio. We developed a new way to fabricate stand-alone microfluidic devices with integrated manifolds and embedded microchannels by utilizing a 3D printing and laser micromachined lamination based hybrid manufacturing approach. In this new fabrication method, we exploit the minimized fabrication steps enabled by 3D printing, and reduced assembly complexities facilitated by laser micromachined lamination method. The new hybrid fabrication method enables key features for advanced microfluidic system architecture: (i) increased design complexity in 3D, (ii) improved control over microflow behavior in all three directions and in multiple layers, (iii) transverse multilayer flow and precisely integrated flow distribution, and (iv) enhanced transparency for high resolution imaging and analysis. Hybrid manufacturing approaches hold great potential in advancing microfluidic device fabrication in terms of standardization, fast production, and user-independent manufacturing.

  6. Confined thermocapillary motion of a three-dimensional deformable drop

    Science.gov (United States)

    Brady, P. T.; Herrmann, M.; Lopez, J. M.

    2011-02-01

    In this paper, simulations are performed of the thermocapillary motion of three-dimensional and axisymmetric drops in a confined apparatus. The refined level-set grid method is used to track the interface and resolve very small deformations. We compare our results to theoretically predicted thermocapillary migration velocities of drops and to experimentally measured migration velocities in microgravity experiments. The motivation of the present work is to address four important questions surrounding thermocapillary migration. These are as follows. (1) What is the impact of initial conditions on both the initial transient and steady state drop behavior? (2) What is the impact of the domain geometry on drop behavior? (3) Do drops deform for intermediate Marangoni numbers and are those deformations axisymmetric? (4) Can the assumption of constant temperature fluid properties be used when simulating physical experiments? To answer the first question, we explore the parameter space of initial drop temperature distribution and drop holding time. We find that in lower Marangoni number regimes, the drop rapidly settles to a quasisteady state. For larger Marangoni numbers, the initial conditions dominate the drop behavior. To address the second and third questions, we look at the spatial distribution of tangential temperature gradients on the surface of the drop as well as drop deformations and migration velocities. The domain geometry induces nonaxisymmetric deformations and temperature distributions. The results of several axisymmetric runs with realistic physical properties are examined to answer the fourth question. It is found that the variation of material properties influences the drop migration behavior in a nontrivial way.

  7. Bulk focused ion beam fabrication with three-dimensional shape control of nanoelectromechanical systems

    International Nuclear Information System (INIS)

    Vick, D; Sauer, V; Freeman, M R; Hiebert, W K; Fraser, A E

    2010-01-01

    Although focused ion beam (FIB) milling has previously been used for fabrication of compliant nanostructures and devices, few instances of FIB nanomachining of such devices out of bulk materials have been reported. We use FIB to fabricate nanoelectromechanical systems (NEMS) devices out of bulk materials. Ion impingement from multiple directions allows sculpting with considerable three-dimensional control of device shape, including tapering and notching. Finite-element modeling of device frequencies agrees with optical interferometric measurements, including for the effect of a localized notch. We envision that bulk FIB fabrication will be useful for NEMS prototyping, milling of tough-to-machine materials and generalized nanostructure fabrication with three-dimensional shape control

  8. Double epitaxy as a paradigm for templated growth of highly ordered three-dimensional mesophase crystals

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Yongsoon; Tao, Jinhui; Arey, Bruce W.; Wang, Chongmin; Exarhos, Gregory J.; De Yoreo, James J.; Sushko, Maria L.; Liu, Jun

    2016-08-30

    Molecular templating and self-assembly are fundamental mechanisms for controlling the morphology of biominerals, while in synthetic two-dimensional layered materials similar levels of control over materials structure can be achieved through the epitaxial relationship with the substrate. In this study these two concepts are combined to provide an approach for the nucleation and growth of three-dimensional ordered mesophases on solid surfaces. A combined experimental and theoretical study revealed how atomic ordering of the substrate controls the structure of surfactant template and the orientation and morphology of the epitaxially grown inorganic material. Such dual epitaxial relationship between the substrate, surfactant template and inorganic mesophase gives rise to a highly ordered porous mesophase with a well-defined cubic lattice of pores. The level of control over material’s three-dimensional architecture achieved in this one-step synthesis is reminiscent to that in biomineralization.

  9. Stability Loss and Buckling Delamination Three-Dimensional Linearized Approach for Elastic and Viscoelastic Composites

    CERN Document Server

    Akbarov, Surkay

    2013-01-01

    This book investigates stability loss and buckling delamination problems of the viscoelastic composite materials and structural members made from these materials within the framework of the Three-Dimensional Linearized Theory of Stability (TDLTS). The investigation of stability loss problems is based on the study of an evolution of the initial infinitesimal imperfection in the structure of the material or of the structural members with time (for viscoelastic composites) or with external compressing forces (for elastic composites). This study is made within the scope of the Three-Dimensional Geometrically Non-Linear Theory of the Deformable Solid Body Mechanics. The solution to the corresponding boundary-value problems is presented in the series form in a small parameter which characterizes the degree of the initial imperfection. The boundary form perturbation technique is employed and nonlinear problems for the domains bounded by noncanonical surfaces are reduced to the same nonlinear problem for the correspo...

  10. Echocardiography derived three-dimensional printing of normal and abnormal mitral annuli

    Directory of Open Access Journals (Sweden)

    Feroze Mahmood

    2014-01-01

    Full Text Available Aims and Objectives: The objective of this study was to assess the clinical feasibility of using echocardiographic data to generate three-dimensional models of normal and pathologic mitral valve annuli before and after repair procedures. Materials and Methods: High-resolution transesophageal echocardiographic data from five patients was analyzed to delineate and track the mitral annulus (MA using Tom Tec Image-Arena software. Coordinates representing the annulus were imported into Solidworks software for constructing solid models. These solid models were converted to stereolithographic (STL file format and three-dimensionally printed by a commercially available Maker Bot Replicator 2 three-dimensional printer. Total time from image acquisition to printing was approximately 30 min. Results: Models created were highly reflective of known geometry, shape and size of normal and pathologic mitral annuli. Post-repair models also closely resembled shapes of the rings they were implanted with. Compared to echocardiographic images of annuli seen on a computer screen, physical models were able to convey clinical information more comprehensively, making them helpful in appreciating pathology, as well as post-repair changes. Conclusions: Three-dimensional printing of the MA is possible and clinically feasible using routinely obtained echocardiographic images. Given the short turn-around time and the lack of need for additional imaging, a technique we describe here has the potential for rapid integration into clinical practice to assist with surgical education, planning and decision-making.

  11. X-ray computed tomography of packed bed chromatography columns for three dimensional imaging and analysis.

    Science.gov (United States)

    Johnson, T F; Levison, P R; Shearing, P R; Bracewell, D G

    2017-03-03

    Physical characteristics critical to chromatography including geometric porosity and tortuosity within the packed column were analysed based upon three dimensional reconstructions of bed structure in-situ. Image acquisition was performed using two X-ray computed tomography systems, with optimisation of column imaging performed for each sample in order to produce three dimensional representations of packed beds at 3μm resolution. Two bead materials, cellulose and ceramic, were studied using the same optimisation strategy but resulted in differing parameters required for X-ray computed tomography image generation. After image reconstruction and processing into a digital three dimensional format, physical characteristics of each packed bed were analysed, including geometric porosity, tortuosity, surface area to volume ratio as well as inter-bead void diameters. Average porosities of 34.0% and 36.1% were found for ceramic and cellulose samples and average tortuosity readings at 1.40 and 1.79 respectively, with greater porosity and reduced tortuosity overall values at the centre compared to the column edges found in each case. X-ray computed tomography is demonstrated to be a viable method for three dimensional imaging of packed bed chromatography systems, enabling geometry based analysis of column axial and radial heterogeneity that is not feasible using traditional techniques for packing quality which provide an ensemble measure. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  12. Data Visualization in Physics II: VRML and Java for three-dimensional imaging and fully three-dimensional movies

    Science.gov (United States)

    Fenton, Flavio H.; Evans, Steven J.; Hastings, Harold M.; Cherry, Elizabeth M.

    2006-03-01

    Presentation and analysis of large three-dimensional data sets is in general hard to do using only two-dimensional figures and plots. In this talk, we will demonstrate techniques for illustrating static and dynamic three-dimensional objects and data using Virtual Reality Modeling Language (VRML) as well as Java. The advantage of these two languages is that they are platform-independent, which allows for easy sharing of data and visualizations. In addition, manipulation of data is relatively easy as rotation, translation and zooming can be done in real- time for static objects as well as for data and objects that vary and deform in time. Examples of fully three-dimensional movies will be shown, including dendritic growth and propagation of electrical waves in cardiac tissue. In addition, we will show how to include VRML and Java viewers in PowerPoint for easy presentation of results in classes and seminars.

  13. Tailor-made three-dimensional hybrid scaffolds for cell cultures

    International Nuclear Information System (INIS)

    Psycharakis, Stylianos; Melissinaki, Vasileia; Giakoumaki, Anastasia; Ranella, Anthi; Tosca, Androniki

    2011-01-01

    The construction of the ideal three-dimensional scaffold for cell culture is one of the most intriguing topics in tissue engineering. It has been shown that cells can be cultured on most organic biomimetic materials, which now are losing popularity in favour of novel, hybrid systems. In this study, a series of photosensitive sol-gel hybrid materials, based on silicon-zirconium and silicon-titanium oxides, have been investigated for their suitability in three-dimensional scaffold fabrication. These materials can be structured by two-photon polymerization, a laser-based technique allowing the fabrication of micrometre-size structures with submicron resolution. The work presented here examined the effect of the organic/inorganic composition of the materials on cell behaviour and the establishment of a 'cell-culture friendly' environment. This is vital for cell adhesion, growth and differentiation, as the organic part of the material provides the soft matrix for cell growth, whereas the inorganic component gives the mechanical stability and rigidity of the three-dimensional structures. In addition, the use of femtosecond laser structuring permits the fabrication of a wide range of mechanically stable scaffolds of different sizes and shapes to be tested in terms of cell viability, proliferation and orientation.

  14. Acid-base properties of complexes with three-dimensional polyligands. Complexes with three-dimensional polyphosphoric acids

    International Nuclear Information System (INIS)

    Kopylova, V.D.; Bojko, Eh.T.; Saldadze, K.M.

    1985-01-01

    By the method of potentiometric titration acid-base properties of uranyl (2) complexes with three-dimensional polyphosphoric acids, KRF-8p, KF-1, KF-7 prepared by phosphorylation of copolymer of styrene and divinylbenzene or saponification of the copolymers of di-2,2'-chloroethyl ester of vinylphosphonic acid with divinyl benzene are studied. It is shown that in case of formation in the phase of three-dimensional polyphosphoric acids of UO 2 2+ complexes with the growth of bond covalence of metal ion-phosphonic group the acidjty of the second hydroxyl of the phosphonic group increases

  15. Signal processing of eddy current three-dimensional maps

    International Nuclear Information System (INIS)

    Birac, C.; David, D.; Lamant, D.

    1987-01-01

    Digital processing of eddy current three-dimensional maps improves accuracy of detection: flattening, filtering, computing deconvolution, mapping new variables,.., give new possibilities for difficult test problems. With simulation of defects, probes, probe travels, it is now possible to compute new eddy current processes, without machining defects or building probes

  16. Three-dimensional flow and turbulence structure in electrostatic precipitator

    DEFF Research Database (Denmark)

    Ullum, Thorvald Uhrskov; Larsen, Poul Scheel; Özcan, Oktay

    2002-01-01

    and bulk velocity U0 on secondary flows and turbulence levels and structures due to the action of the three-dimensional electrostatic field on the charged gas. At constant bulk velocity (U0 = 1 m/s) and current density (Jm = 0.4 mA/m2), secondary flows in the form of rolls of axial vorticity with swirl...

  17. Two-and three-dimensional gravity modeling along western ...

    Indian Academy of Sciences (India)

    The western continental margin and the intraplate Narmada-Tapti rifts are primarily covered by Deccan flood basalts. Three-dimensional gravity modeling of +70 mgal Bouguer gravity highs extending in the north-south direction along the western continental margin rift indicates the presence of a subsurface high density, ...

  18. Kondo effect in three-dimensional Dirac and Weyl systems

    NARCIS (Netherlands)

    Mitchell, Andrew K.; Fritz, Lars

    2015-01-01

    Magnetic impurities in three-dimensional Dirac and Weyl systems are shown to exhibit a fascinatingly diverse range of Kondo physics, with distinctive experimental spectroscopic signatures. When the Fermi level is precisely at the Dirac point, Dirac semimetals are in fact unlikely candidates for a

  19. Rigid isotopy classification of real three-dimensional cubics

    Energy Technology Data Exchange (ETDEWEB)

    Krasnov, Vyacheslav A [Yaroslavl Demidov State University (Russian Federation)

    2006-08-31

    We prove that the space of non-singular real three-dimensional cubics has precisely nine connected components. We also study the space of real canonical curves of genus 4 and prove, in particular, that it consists of eight connected components.

  20. Three-dimensional fractal geometry for gas permeation in microchannels

    NARCIS (Netherlands)

    Malankowska, Magdalena; Schlautmann, Stefan; Berenschot, Erwin J.W.; Tiggelaar, Roald M.; Pina, Maria Pilar; Mallada, Reyes; Tas, Niels R.; Gardeniers, Han

    2018-01-01

    The novel concept of a microfluidic chip with an integrated three-dimensional fractal geometry with nanopores, acting as a gas transport membrane, is presented. The method of engineering the 3D fractal structure is based on a combination of anisotropic etching of silicon and corner lithography. The

  1. Monitoring the three-dimensional ionospheric electron density ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 116; Issue 3. Monitoring the three-dimensional ionospheric ... A numerical experiment is used to validate the reliability of the method and its advantages to the classical algebraic reconstruction technique (ART). This is then used to reconstruct the IED images using ...

  2. A Three-Dimensional Haptic Matrix Test of Nonverbal Reasoning

    Science.gov (United States)

    Miller, Joseph C.; Skillman, Gemma D.; Benedetto, Joanne M.; Holtz, Ann M.; Nassif, Carrie L.; Weber, Anh D.

    2007-01-01

    Three-dimensional haptic matrices were pilot-tested as a nonvisual measure of cognitive ability. The results indicated that they correlated with convergent measures, with emphasis on spatial processing and that the participants who described items "visually" completed them more quickly and accurately and tended to have become visually…

  3. Freehand three-dimensional ultrasound to assess semitendinosus muscle morphology

    NARCIS (Netherlands)

    Haberfehlner, H.; Maas, H.; Harlaar, J.; Becher, J.G.; Buizer, A.I.; Jaspers, R.T.

    2016-01-01

    In several neurological disorders and muscle injuries, morphological changes of the m. semitendinosus (ST) are presumed to contribute to movement limitations around the knee. Freehand three-dimensional (3D) ultrasound (US), using position tracking of two-dimensional US images to reconstruct a 3D

  4. Quantum field between moving mirrors: A three dimensional example

    Science.gov (United States)

    Hacyan, S.; Jauregui, Roco; Villarreal, Carlos

    1995-01-01

    The scalar quantum field uniformly moving plates in three dimensional space is studied. Field equations for Dirichlet boundary conditions are solved exactly. Comparison of the resulting wavefunctions with their instantaneous static counterpart is performed via Bogolubov coefficients. Unlike the one dimensional problem, 'particle' creation as well as squeezing may occur. The time dependent Casimir energy is also evaluated.

  5. Three-dimensional reconstruction of the pigeon inner ear

    NARCIS (Netherlands)

    Hofman, R.; Segenhout, J. M.; Wit, H. P.

    2009-01-01

    Three-dimensional reconstructions of the inner ear of the pigeon (Columba livia domestica), from two-dimensional images, obtained with (conventional) light microscopy or orthogonal-plane fluorescence optical sectioning (OPFOS), are presented. The results are compared with available information on

  6. Three-dimensional structure of heat shock protein 90 from ...

    Indian Academy of Sciences (India)

    Madhu Sudhan

    2007-04-02

    Apr 2, 2007 ... Using inhibitors specific to the nucleotide binding domain of Hsp90, we have shown potent growth inhibitory ... role played by PfHsp90 in parasite growth, we have modeled its three dimensional structure using recently described full length .... PfHsp90 and for the development of small-molecule targets.

  7. Three-dimensional reconstruction of the rat nephron

    DEFF Research Database (Denmark)

    Christensen, Erik Ilsø; Grann, Birgitte; Kristoffersen, Inger B.

    2014-01-01

    This study gives a three-dimensional (3D) structural analysis of rat nephrons and their connections to collecting ducts. Approximately 4,500 2.5-μm-thick serial sections from the renal surface to the papillary tip were obtained from each of 3 kidneys of Wistar rats. Digital images were recorded...

  8. Three dimensional reconstruction of tomographic images of the retina

    International Nuclear Information System (INIS)

    Glittenberg, C.; Zeiler, F.; Falkner, C.; Binder, S.; Povazay, B.; Hermann, B.; Drexler, W.

    2007-01-01

    The development of a new display system for the three-dimensional visualization of tomographic images in ophthalmology. Specifically, a system that can use stacks of B-mode scans from an ultrahigh resolution optical tomography examination to vividly display retinal specimens as three-dimensional objects. Several subroutines were programmed in the rendering and raytracing program Cinema 4D XL 9.102 Studio Bundle (Maxon Computer Inc., Friedrichsburg, Germany), which could process stacks of tomographic scans into three-dimensional objects. Ultrahigh resolution optical coherence tomography examinations were performed on patients with various retinal pathologies and post processed with the subroutines that had been designed. All ultrahigh resolution optical coherence tomographies were performed with a titanium: sapphire based ultra broad bandwidth (160 nm) femtosecond laser system (INTEGRAL, Femtolasers Productions GmbH. Vienna Austria) with an axial resolution of 3 μm. A new three dimensional display system for tomographic images in ophthalmology was developed, which allows a highly vivid display of physiological and pathological structures of the retina. The system also distinguishes itself through its high interactivity and adaptability. This new display system allows the visualization of physiological and pathological structures of the retina in a new way, which will give us new insight into their morphology and development. (author) [de

  9. hp Spectral element methods for three dimensional elliptic problems ...

    Indian Academy of Sciences (India)

    125, No. 3, August 2015, pp. 413–447. c Indian Academy of Sciences h-p Spectral element methods for three dimensional elliptic problems on non-smooth domains, Part-II: Proof of stability theorem. P DUTT1, AKHLAQ HUSAIN2,∗, A S VASUDEVA MURTHY3 and C S UPADHYAY4. 1Department of Mathematics & Statistics ...

  10. Three-dimensional echocardiographic assessment of the repaired mitral valve.

    Science.gov (United States)

    Maslow, Andrew; Mahmood, Feroze; Poppas, Athena; Singh, Arun

    2014-02-01

    This study examined the geometric changes of the mitral valve (MV) after repair using conventional and three-dimensional echocardiography. Prospective evaluation of consecutive patients undergoing mitral valve repair. Tertiary care university hospital. Fifty consecutive patients scheduled for elective repair of the mitral valve for regurgitant disease. Intraoperative transesophageal echocardiography. Assessments of valve area (MVA) were performed using two-dimensional planimetry (2D-Plan), pressure half-time (PHT), and three-dimensional planimetry (3D-Plan). In addition, the direction of ventricular inflow was assessed from the three-dimensional imaging. Good correlations (r = 0.83) and agreement (-0.08 +/- 0.43 cm(2)) were seen between the MVA measured with 3D-Plan and PHT, and were better than either compared to 2D-Plan. MVAs were smaller after repair of functional disease repaired with an annuloplasty ring. After repair, ventricular inflow was directed toward the lateral ventricular wall. Subgroup analysis showed that the change in inflow angle was not different after repair of functional disease (168 to 171 degrees) as compared to those presenting with degenerative disease (168 to 148 degrees; p<0.0001). Three-dimensional imaging provides caregivers with a unique ability to assess changes in valve function after mitral valve repair. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Mathematical modeling of three-dimensional images in emission tomography

    International Nuclear Information System (INIS)

    Koblik, Yu.N.; Khugaev, A. V.; Mktchyan, G.A.; Ioannou, P.; Dimovasili, E.

    2002-01-01

    The model of processing results of three-dimensional measurements in positron-emissive tomograph is proposed in this work. The algorithm of construction and visualization of phantom objects of arbitrary shape was developed and its concrete realization in view of program packet for PC was carried out

  12. Analysis of three-dimensional transient seepage into ditch drains ...

    Indian Academy of Sciences (India)

    Ratan Sarmah

    Abstract. An analytical solution in the form of infinite series is developed for predicting time-dependent three-dimensional seepage into ditch drains from a flat, homogeneous and anisotropic ponded field of finite size, the field being assumed to be surrounded on all its vertical faces by ditch drains with unequal water level ...

  13. Singularities at rims in three-dimensional fluid flow

    NARCIS (Netherlands)

    Driesen, C.H.; Kuerten, Johannes G.M.

    1999-01-01

    Asymptotic solutions are presented for Stokes flow near circular rims in three-dimensional geometries. Using nonstandard toroidal coordinates, asymptotic analytical expressions are derived for different corner angles. In comparison to the two-dimensional case, an extra critical corner angle value is

  14. and three-dimensional gravity modeling along western continental ...

    Indian Academy of Sciences (India)

    Three-dimensional gravity modeling of +70 mgal Bouguer gravity highs extending in the north-south direction along the western continental margin rift indicates the presence of a subsurface high density, mafic-ultramafic type, elongated, roughly ellipsoidal body. It is approximately 12.0 ± 1.2 km thick with its upper surface at ...

  15. Wave packet construction in three-dimensional quantum billiards ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 86; Issue 1. Wave packet construction in three-dimensional quantum billiards: Visualizing the closed orbit, collapse and revival of wave packets in the cubical billiard. Maninder Kaur Bindiya Arora Mahmood Mian. Volume 86 Issue 1 January 2016 pp 31-48 ...

  16. Three-dimensional simulation of laser–plasma-based electron ...

    Indian Academy of Sciences (India)

    Abstract. A sequential three-dimensional (3D) particle-in-cell simulation code PICPSI-3D with a user friendly graphical user interface (GUI) has been developed and used to study the interaction of plasma with ultrahigh intensity laser radiation. A case study of laser–plasma-based electron acceleration has been carried out ...

  17. Generation of a Desired Three-Dimensional Electromagnetic Field

    DEFF Research Database (Denmark)

    2005-01-01

    The present invention relates to a method and a system for synthesizing a prescribed three-dimensional electromagnetic field based on generalized phase contrast imaging. Such a method and apparatus may be utilized in advanced optical micro and nano-manipulation, such as by provision of a multiple...

  18. Three-dimensional group manifold reductions of gravity

    Science.gov (United States)

    Linares, Román

    2005-04-01

    We review the three-dimensional group manifold reductions of pure Einstein gravity and we exhibit a new consistent group manifold reduction of gravity when the compactification group manifold is S3. The new reduction leads to a lower dimensional theory whose gauge group is SU(2).

  19. Robust cylinder fitting in three-dimensional point cloud data

    NARCIS (Netherlands)

    Nurunnabi, Abdul; Sadahiro, Yukio; Lindenbergh, R.C.

    2017-01-01

    This paper investigates the problems of cylinder fitting in laser scanning three-dimensional Point Cloud Data (PCD). Most existing methods require full cylinder data, do not study the presence of outliers, and are not statistically robust. But especially mobile laser scanning often has incomplete

  20. The Importance of Three-Dimensionality in Children's Art

    Science.gov (United States)

    Heldmeyer, Karen

    1978-01-01

    Investigated young children's ability to represent three-dimensionality in their drawings. Preschool, kindergarten and first grade children and adults were asked to draw a cube, a house, and a ball presented in a plain form, a form differentially decorated on each side, and in both 2- and 3-dimensional forms. (JMB)

  1. Three-Dimensional Extension of a Digital Library Service System

    Science.gov (United States)

    Xiao, Long

    2010-01-01

    Purpose: The paper aims to provide an overall methodology and case study for the innovation and extension of a digital library, especially the service system. Design/methodology/approach: Based on the three-dimensional structure theory of the information service industry, this paper combines a comprehensive analysis with the practical experiences…

  2. Three dimensional simulated modelling of diffusion capacitance of ...

    African Journals Online (AJOL)

    A three dimensional (3-D) simulated modelling was developed to analyse the excess minority carrier density in the base of a polycrystalline bifacial silicon solar cell. The concept of junction recombination velocity was ado-pted to quantify carrier flow through the junction, and to examine the solar cell diffusion capacitance for ...

  3. Three-Dimensional Utah: 100 Years of Sculpture

    OpenAIRE

    Nora Eccles Harrison Museum of Art

    1996-01-01

    Three-Dimensional Utah: 100 Years of Sculpture began as a series of conversations about sculptors and sculpture nearly six years ago. Specific development of the exhibition began three years ago during the process of creating a national inventory of outdoor sculpture for a program called Save Outdoor Sculpture (SOS)! Utah is home to more than 200 pieces of outdoor sculpture.

  4. Three-dimensional computer models of electrospinning systems

    Directory of Open Access Journals (Sweden)

    Smółka Krzysztof

    2017-12-01

    Full Text Available Electrospinning is a very interesting method that allows the fabrication of continuous fibers with diameters down to a few nanometers. This paper presents an overview of electrospinning systems as well as their comparison using proposed three-dimensional parameterized numerical models. The presented solutions allow an analysis of the electric field distribution.

  5. Molecular dynamics study of two- and three-dimensional classical ...

    Indian Academy of Sciences (India)

    Abstract. We have carried out a molecular dynamics simulation of two- and three- dimensional double Yukawa fluids near the triple point. We have compared some of the static and dynamic correlation functions with those of Lennard–Jones, when parameters occurring in double Yukawa potential are chosen to fit ...

  6. Resistive drift wave turbulence in a three-dimensional geometry

    DEFF Research Database (Denmark)

    Korsholm, Søren Bang; Michelsen, Poul; Naulin, V.

    1999-01-01

    The Hasegawa-Wakatani model describing resistive drift waves is investigated analytically and numerically in a three-dimensional periodic geometry. After an initial growth of the energy the drift waves couple nonlinearly to convective cells, which eventually dominate the system completely...

  7. and three-dimensional models for analysis of optical absorption

    Indian Academy of Sciences (India)

    Unknown

    Goldberg et al 1975; Kam and Parkinson 1982; Baglio et al 1982, 1983; Oritz 1995; Li et al 1996) has been carried out on WS2, there is no detailed analysis of the absorption spectra obtained from the single crystals of WS2 on the basis of two- and three-dimensional models. We have therefore carried out this study and the.

  8. Optical and thermal performance of a three-dimensional compound ...

    Indian Academy of Sciences (India)

    The three-dimensional compound parabolic concentrator (3D CPC) was found to be more efficient than 2D CPC because of the higher concentration ratio. In the present work a 3D CPC was fabricated with a half acceptance angle of 4° for a spherical absorber of radius 100 mm. UV stabilized aluminized polyester foil having ...

  9. Wave packet construction in three-dimensional quantum billiards ...

    Indian Academy of Sciences (India)

    Keywords. Three-dimensional bound systems; revivals and collapses; quantum mechanics. PACS Nos 03.65.Ge; 03.65.Yz; 42.50.Md. 1. Introduction. The study of time evolution of the unbound and bound-state wave packet illuminates many features of the wave mechanics. These include both semiclassical features as well.

  10. KP Equation in a Three-Dimensional Unmagnetized Warm Dusty ...

    Indian Academy of Sciences (India)

    Kh. H. El-Shorbagy

    yahoo.com. MS received 24 May 2017; accepted 26 September 2017; published online 27 November 2017. Abstract. In this work, we investigate the propagation of three-dimensional nonlinear dust-acoustic and dust-. Coulomb waves in an ...

  11. Three-dimensional free vibration analysis of thick laminated circular ...

    African Journals Online (AJOL)

    Three-dimensional free vibration analysis of thick laminated circular plates. Sumit Khare, N.D. Mittal. Abstract. In this communication, a numerical analysis regarding free vibration of thick laminated circular plates, having free, clamped as well as simply-supported boundary conditions at outer edges of plates is presented.

  12. and three-dimensional gravity modeling along western continental ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    western continental margin and the intraplate Narmada-Tapti rifts suggests that the migration and concentration of high density magma in the upper lithosphere was much more dominant along the western continental margin rift. Based on the three-dimensional gravity modeling, it is conjectured that the emplacement of ...

  13. Three dimensional rigorous model for optical scattering problems

    NARCIS (Netherlands)

    Wei, X.

    2006-01-01

    We present a three-dimensional model based on the finite element method for solving the time-harmonic Maxwell equation in optics. It applies to isotropic or anisotropic dielectrics and metals, and to many configurations such as an isolated scatterer in a multilayer, bi-gratings and crystals. We

  14. Stability analysis of non-axisymmetric three-dimensional finite ...

    Indian Academy of Sciences (India)

    In three-dimensional formulation one prefers a spinning frame for derivation of the govern- ing equations (Nandi & Neogy 2001). In this spinning frame, the orthotropic bearing stiffness becomes periodic. The governing equations thus become parametric in nature. A rotor cross- section is symmetric when the rotor has same ...

  15. Three-dimensional simulations of viscoelastic instability in polymeric filaments

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Hassager, Ole

    1999-01-01

    The three-dimensional Langrangian integral method is used to simulate the elastic end-plate instability that occurs in the rapid extension of some polymeric filaments between parallel plates. It is demonstrated that the upper convected Maxwell model describes the essential features of the instabi...

  16. Three-dimensional computer models of electrospinning systems

    Science.gov (United States)

    Smółka, Krzysztof; Firych-Nowacka, Anna; Lefik, Marcin

    2017-12-01

    Electrospinning is a very interesting method that allows the fabrication of continuous fibers with diameters down to a few nanometers. This paper presents an overview of electrospinning systems as well as their comparison using proposed three-dimensional parameterized numerical models. The presented solutions allow an analysis of the electric field distribution.

  17. Three dimensional internal electromagnetic pulse calculated by particle source method

    International Nuclear Information System (INIS)

    Wang Yuzhi; Wang Taichun

    1986-01-01

    The numerical results of the primary electric current and the internal electromagnetic pulse were obtained by particle method in the rectanglar cavity. The results obtained from this method is compared with three dimensional Euler-method. It is shown that two methods are in good agreement if the conditions are the same

  18. Three-dimensional observation of TiO2 nanostructures by electron tomography

    KAUST Repository

    Suh, Young Joon

    2013-03-01

    Three-dimensional nanostructures of TiO2 related materials including nanotubes, electron acceptor materials in hybrid polymer solar cells, and working electrodes of dye sensitized solar cells (DSSCs) were visualized by electron tomography as well as TEM micrographs. The regions on the wall of TiO2 nanotubes where the streptavidins were attached were elucidated by electron tomogram analysis. The coverage of TiO2 nanotubes by streptavidin was also investigated. The TiO2 nanostructures in hybrid polymer solar cells made by sol-gel and atomic layer deposition (ALD) methods and the morphologies of pores between TiO2 particles in DSSCs were also observed by reconstructed three-dimensional images made by electron tomography. © 2012 Elsevier Ltd.

  19. Three-dimensional observation of TiO2 nanostructures by electron tomography.

    Science.gov (United States)

    Suh, Young Joon; Lu, Ning; Park, Seong Yong; Lee, Tae Hun; Lee, Sang Hoon; Cha, Dong Kyu; Lee, Min Gun; Huang, Jie; Kim, Sung-Soo; Sohn, Byeong-Hyeok; Kim, Geung-Ho; Ko, Min Jae; Kim, Jiyoung; Kim, Moon J

    2013-03-01

    Three-dimensional nanostructures of TiO2 related materials including nanotubes, electron acceptor materials in hybrid polymer solar cells, and working electrodes of dye sensitized solar cells (DSSCs) were visualized by electron tomography as well as TEM micrographs. The regions on the wall of TiO2 nanotubes where the streptavidins were attached were elucidated by electron tomogram analysis. The coverage of TiO2 nanotubes by streptavidin was also investigated. The TiO2 nanostructures in hybrid polymer solar cells made by sol-gel and atomic layer deposition (ALD) methods and the morphologies of pores between TiO2 particles in DSSCs were also observed by reconstructed three-dimensional images made by electron tomography. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Three-dimensional photochemical microfabrication of poly(3,4-ethylene- dioxythiophene) in transparent polymer sheet

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Katsumi, E-mail: kyamada@chem.t-kougei.ac.jp [Department of Life Science and Sustainable Chemistry, Tokyo Polytechnic University, 1583 Iiyama, Atsugi, Kanagawa, 243-0297 (Japan); Yamada, Yumiko [Department of Life Science and Sustainable Chemistry, Tokyo Polytechnic University, 1583 Iiyama, Atsugi, Kanagawa, 243-0297 (Japan); Sone, Junji [Department of Applied Computer Science, Tokyo Polytechnic University, 1583 Iiyama, Atsugi, Kanagawa, 243-0297 (Japan)

    2014-03-03

    A dimeric compound of 3,4-ethylenedioxythiophene was polymerized to form poly(3,4-ethylenedioxythiophene) by multi-photon sensitized polymerization using a femtosecond laser. In contrast, photopolymerization could not be achieved using 3,4-ethylenedioxythiophene as the starting material, because it has a more positive oxidation peak potential compared to the redox potential of the tris(2,2′-bipyridyl)ruthenium complex used as the photosensitizer. Furthermore, three-dimensional micropatterns of poly(3,4-ethylenedioxythiophene) could be produced in a transparent polymer sheet by scanning the laser focal point. - Highlights: • Multi-photon sensitized polymerization of 3,4-ethylenedioxythiophene (EDOT). • Three-dimensional microstructures of poly(EDOT) in the transparent polymer sheet. • The dimeric compound of EDOT was employed as the starting material. • The lateral precision of this system exceeded the diffraction limit.

  1. Two- to three-dimensional crossover in a dense electron liquid in silicon

    Science.gov (United States)

    Matmon, Guy; Ginossar, Eran; Villis, Byron J.; Kölker, Alex; Lim, Tingbin; Solanki, Hari; Schofield, Steven R.; Curson, Neil J.; Li, Juerong; Murdin, Ben N.; Fisher, Andrew J.; Aeppli, Gabriel

    2018-04-01

    Doping of silicon via phosphine exposures alternating with molecular beam epitaxy overgrowth is a path to Si:P substrates for conventional microelectronics and quantum information technologies. The technique also provides a well-controlled material for systematic studies of two-dimensional lattices with a half-filled band. We show here that for a dense (ns=2.8 ×1014 cm-2) disordered two-dimensional array of P atoms, the full field magnitude and angle-dependent magnetotransport is remarkably well described by classic weak localization theory with no corrections due to interaction. The two- to three-dimensional crossover seen upon warming can also be interpreted using scaling concepts developed for anistropic three-dimensional materials, which work remarkably except when the applied fields are nearly parallel to the conducting planes.

  2. X-ray ablation of hyaluronan hydrogels: Fabrication of three-dimensional microchannel networks

    Science.gov (United States)

    Weon, B. M.; Chang, S.; Yeom, J.; Hahn, S. K.; Je, J. H.; Hwu, Y.; Margaritondo, G.

    2009-09-01

    We present a simple and highly versatile protocol for polymer ablation: hard x-ray irradiation makes it possible to rapidly depolymerize hyaluronan hydrogels and fabricate three-dimensional network of microchannels. Photodynamic and photochemical analyses show that x-ray irradiation directly cleaves the polymer backbone and the total dose controls the degradation kinetics. This nonthermal ablation protocol may offer opportunities for processing organic polymers and biological materials.

  3. Three-dimensional printing of freeform helical microstructures: a review

    Science.gov (United States)

    Farahani, R. D.; Chizari, K.; Therriault, D.

    2014-08-01

    Three-dimensional (3D) printing is a fabrication method that enables creation of structures from digital models. Among the different structures fabricated by 3D printing methods, helical microstructures attracted the attention of the researchers due to their potential in different fields such as MEMS, lab-on-a-chip systems, microelectronics and telecommunications. Here we review different types of 3D printing methods capable of fabricating 3D freeform helical microstructures. The techniques including two more common microfabrication methods (i.e., focused ion beam chemical vapour deposition and microstereolithography) and also five methods based on computer-controlled robotic direct deposition of ink filament (i.e., fused deposition modeling, meniscus-confined electrodeposition, conformal printing on a rotating mandrel, UV-assisted and solvent-cast 3D printings) and their advantages and disadvantages regarding their utilization for the fabrication of helical microstructures are discussed. Focused ion beam chemical vapour deposition and microstereolithography techniques enable the fabrication of very precise shapes with a resolution down to ~100 nm. However, these techniques may have material constraints (e.g., low viscosity) and/or may need special process conditions (e.g., vacuum chamber) and expensive equipment. The five other techniques based on robotic extrusion of materials through a nozzle are relatively cost-effective, however show lower resolution and less precise features. The popular fused deposition modeling method offers a wide variety of printable materials but the helical microstructures manufactured featured a less precise geometry compared to the other printing methods discussed in this review. The UV-assisted and the solvent-cast 3D printing methods both demonstrated high performance for the printing of 3D freeform structures such as the helix shape. However, the compatible materials used in these methods were limited to UV-curable polymers and

  4. Self-assembly of polyhedral metal-organic framework particles into three-dimensional ordered superstructures

    Science.gov (United States)

    Avci, Civan; Imaz, Inhar; Carné-Sánchez, Arnau; Pariente, Jose Angel; Tasios, Nikos; Pérez-Carvajal, Javier; Alonso, Maria Isabel; Blanco, Alvaro; Dijkstra, Marjolein; López, Cefe; Maspoch, Daniel

    2018-01-01

    Self-assembly of particles into long-range, three-dimensional, ordered superstructures is crucial for the design of a variety of materials, including plasmonic sensing materials, energy or gas storage systems, catalysts and photonic crystals. Here, we have combined experimental and simulation data to show that truncated rhombic dodecahedral particles of the metal-organic framework (MOF) ZIF-8 can self-assemble into millimetre-sized superstructures with an underlying three-dimensional rhombohedral lattice that behave as photonic crystals. Those superstructures feature a photonic bandgap that can be tuned by controlling the size of the ZIF-8 particles and is also responsive to the adsorption of guest substances in the micropores of the ZIF-8 particles. In addition, superstructures with different lattices can also be assembled by tuning the truncation of ZIF-8 particles, or by using octahedral UiO-66 MOF particles instead. These well-ordered, sub-micrometre-sized superstructures might ultimately facilitate the design of three-dimensional photonic materials for applications in sensing.

  5. A practical three-dimensional dosimetry system for radiation therapy

    International Nuclear Information System (INIS)

    Guo Pengyi; Adamovics, John; Oldham, Mark

    2006-01-01

    There is a pressing need for a practical three-dimensional (3D) dosimetry system, convenient for clinical use, and with the accuracy and resolution to enable comprehensive verification of the complex dose distributions typical of modern radiation therapy. Here we introduce a dosimetry system that can achieve this challenge, consisting of a radiochromic dosimeter (PRESAGE trade mark sign ) and a commercial optical computed tomography (CT) scanning system (OCTOPUS trade mark sign ). PRESAGE trade mark sign is a transparent material with compelling properties for dosimetry, including insensitivity of the dose response to atmospheric exposure, a solid texture negating the need for an external container (reducing edge effects), and amenability to accurate optical CT scanning due to radiochromic optical contrast as opposed to light-scattering contrast. An evaluation of the performance and viability of the PRESAGE trade mark sign /OCTOPUS, combination for routine clinical 3D dosimetry is presented. The performance of the two components (scanner and dosimeter) was investigated separately prior to full system test. The optical CT scanner has a spatial resolution of ≤1 mm, geometric accuracy within 1 mm, and high reconstruction linearity (with a R 2 value of 0.9979 and a standard error of estimation of ∼1%) relative to independent measurement. The overall performance of the PRESAGE trade mark sign /OCTOPUS system was evaluated with respect to a simple known 3D dose distribution, by comparison with GAFCHROMIC[reg] EBT film and the calculated dose from a commissioned planning system. The 'measured' dose distribution in a cylindrical PRESAGE trade mark sign dosimeter (16 cm diameter and 11 cm height) was determined by optical-CT, using a filtered backprojection reconstruction algorithm. A three-way Gamma map comparison (4% dose difference and 4 mm distance to agreement), between the PRESAGE trade mark sign , EBT and calculated dose distributions, showed full agreement in

  6. Three dimensional conformal radiation therapy in pediatric parameningeal rhabdomyosarcomas

    International Nuclear Information System (INIS)

    Michalski, Jeff M.; Harms, William B.; Purdy, James A.; Sur, Ranjan K.

    1995-01-01

    Purpose: We evaluated the utility of three dimensional (3D) treatment planning in the management of children with parameningeal head and neck rhabdomyosarcomas. Methods and Materials: Five children with parameningeal rhabdomyosarcoma were referred for treatment at our radiation oncology center from May 1990 through January 1993. Each patient was evaluated, staged, and treated according to the Intergroup Rhabdomyosarcoma Study. Patients were immobilized and underwent a computed tomography scan with contrast in the treatment position. Tumor and normal tissues were identified with assistance from a diagnostic radiologist and defined in each slice. The patients were then planned and treated with the assistance of a 3D treatment planning system. A second plan was then devised by another physician without the benefit of the 3D volumetric display. The target volumes designed with the 3D system and the two-dimensional (2D) method were then compared. The dosimetric coverage to tumor, tumor plus margin, and normal tissues was also compared with the two methods of treatment planning. Results: The apparent size of the gross tumor volume was underestimated with the conventional 2D planning method relative to the 3D method. When margin was added around the gross tumor to account for microscopic extension of disease in the 2D method, the expected area of coverage improved relative to the 3D method. In each circumstance, the minimum dose that covered the gross tumor was substantially less with the 2D method than with the 3D method. The inadequate dosimetric coverage was especially pronounced when the necessary margin to account for subclinical disease was added. In each case, the 2D plans would have delivered substantial dose to adjacent normal tissues and organs, resulting in a higher incidence of significant complications. Conclusions: 3D conformal radiation therapy has a demonstrated advantage in the treatment of sarcomas of the head and neck. The improved dosimetric coverage

  7. Informatics solutions for Three-dimensional visualization in real time

    International Nuclear Information System (INIS)

    Guzman Montoto, Jose Ignacio

    2002-01-01

    The advances reached in the development of the hardware and in the methods of acquisition of data like tomographic scanners and systems of analysis of images, have allowed obtaining geometric models of biomedical elements with the property of being manipulated through the three-dimensional visualization (3D). Nowadays, this visualization embraces from biological applications, including analysis of structures and its functional relationships, until medical applications that include anatomical accuracies and the planning or the training for complex surgical operations. This work proposes computer solutions to satisfy visualization requirements in real time. The developed algorithms are contained in a graphic library that will facilitate the development of future works. The obtained results allow facing current problems of three-dimensional representation of complex surfaces, realism is reached in the images and they have possible application in bioinformatics and medicine

  8. Three-dimensional MR imaging of congenital heart disease

    International Nuclear Information System (INIS)

    Laschinger, J.C.; Vannier, M.W.; Knapp, R.H.; Gutierrez, F.R.; Cox, J.L.

    1987-01-01

    Contiguous 5-mm thick ECG-gated MR images of the thorax were edited using surface reconstruction techniques to produce three-dimensional (3D) images of the heart and great vessels in four healthy individuals and 25 patients with congenital heart disease (aged 3 months-30 years). Anomalies studied include atrial and ventricular septal defects, aortic coarctation, AV canal defects, double outlet ventricles, hypoplastic left heart syndrome, and a wide spectrum of patients with tetralogy of Fallot. The results were correlated with echocardiographic and cineradiographic studies, and with surgical findings or pathologic specimens. Three-dimensional reconstructions accurately localized the dimensions and locations of all cardiac and great vessel anomalies and often displayed anatomic findings not diagnosed or visualized with other forms of diagnostic imaging

  9. Polarization singularity anarchy in three dimensional ellipse fields

    Science.gov (United States)

    Freund, Isaac

    2004-11-01

    Lines of circular polarization, C lines, and lines of linear polarization, L lines, are studied in a computer simulated random three-dimensional ellipse field. Although we verify existing predictions for the location of particular points on these lines at which the sign of the topological index of the line inverts, we show that from the point of view of foliations of the field such points are better described as points of pair production. We find a new set of true sign inversion points, and show that when all possible foliations are considered this set includes all points on the line. We also find three new families of polarization singularities whose members include all polarization ellipses. The recently described polarization singularity democracy in two-dimensional fields evidently explodes into polarization singularity anarchy in three-dimensional fields.

  10. Three-dimensional data visualization using DSP meshes

    Science.gov (United States)

    Liow, Yuh-Tay; Civanlar, Mehmet R.; Dzik, Steven C.

    1990-08-01

    This paper presents a parallel scheme for three dimensional data visualization at interactive rates. The scheme is particularly suitable for multiprocessor systems with distributed frame buffers and is currently implemented on an AT&T Pixel Machine, a parallel computer based on mesh connected digital signal processors with a distributed frame buffer. Nearly linear performance increase with the number of processors in the mesh is obtained by partitioning the original three dimensional data into sub-blocks and processing each sub-block in parallel. The approach is very flexible in implementing a variety of visualization techniques, such as volume compositing (translucent models), binary-class and percentage mixtures and surface based volume rendering.

  11. Three-dimensional P velocity structure in Beijing area

    Science.gov (United States)

    Yu, Xiang-Wei; Chen, Yun-Tai; Wang, Pei-De

    2003-01-01

    A detail three-dimensional P wave velocity structure of Beijing, Tianjin and Tangshan area (BTT area) was determined by inverting local earthquake data. In total 16 048 P wave first arrival times from 16048 shallow and mid-depth crustal earthquakes, which occurred in and around the BTT area from 1992 to 1999 were used. The first arrival times are recorded by Northern China United Telemetry Seismic Network and Yanqing-Huailai Digital Seismic Network. Hypocentral parameters of 1 132 earthquakes with magnitude M L=1.7 6.2 and the three-dimensional P wave velocity structure were obtained simultaneously. The inversion result reveals the complicated lateral heterogeneity of P wave velocity structure around BTT area. The tomographic images obtained are also found to explain other seismological observations well.

  12. Three-dimensional Modeling of Type Ia Supernova Explosions

    Science.gov (United States)

    Khokhlov, Alexei

    2001-06-01

    A deflagration explosion of a Type Ia Supernova (SNIa) is studied using three-dimensional, high-resolution, adaptive mesh refinement fluid dynamic calculations. Deflagration speed in an exploding Chandrasekhar-mass carbon-oxygen white dwarf (WD) grows exponentially, reaches approximately 30the speed of sound, and then declines due to a WD expansion. Outermost layers of the WD remain unburned. The explosion energy is comparable to that of a Type Ia supernova. The freezing of turbulent motions by expansion appears to be a crucial physical mechanism regulating the strength of a supernova explosion. In contrast to one-dimensional models, three-dimensional calculations predict the formation of Si-group elements and pockets of unburned CO in the middle and in central regions of a supernova ejecta. This, and the presence of unburned outer layer of carbon-oxygen may pose problems for SNIa spectra. Explosion sensitivity to initial conditions and its relation to a diversity of SNIa is discussed.

  13. Ultrafast three-dimensional x-ray computed tomography

    International Nuclear Information System (INIS)

    Bieberle, Martina; Barthel, Frank; Hampel, Uwe; Menz, Hans-Juergen; Mayer, Hans-Georg

    2011-01-01

    X-ray computed tomography (CT) is a well established visualization technique in medicine and nondestructive testing. However, since CT scanning requires sampling of radiographic projections from different viewing angles, common CT systems with mechanically moving parts are too slow for dynamic imaging, for instance of multiphase flows or live animals. Here, we introduce an ultrafast three-dimensional x-ray CT method based on electron beam scanning, which achieves volume rates of 500 s -1 . Primary experiments revealed the capability of this method to recover the structure of phase boundaries in gas-solid and gas-liquid two-phase flows, which undergo three-dimensional structural changes in the millisecond scale.

  14. SNAP-3D: a three-dimensional neutron diffusion code

    International Nuclear Information System (INIS)

    McCallien, C.W.J.

    1975-10-01

    A preliminary report is presented describing the data requirements of a one- two- or three-dimensional multi-group diffusion code, SNAP-3D. This code is primarily intended for neutron diffusion calculations but it can also carry out gamma calculations if the diffuse approximation is accurate enough. It is suitable for fast and thermal reactor core calculations and for shield calculations. It is assumed the reader is familiar with the older, two-dimensional code SNAP and can refer to the report [TRG-Report-1990], describing it. The present report concentrates on the enhancements to SNAP that have been made to produce the three-dimensional version, SNAP-3D, and is intended to act a a guide on data preparation until a single, comprehensive report can be published. (author)

  15. Three-dimensional computerized tomography in mandibular condyle fractures

    International Nuclear Information System (INIS)

    Bermeo, Fausto; Salazar, Abad

    2003-01-01

    Now, car accidents are so commons, this associated to the high technology in produce automobiles make this type of accidents so serious and the consequences of mandibular condyle fractures are more commons and with more gravity, some of these patients, generally need a traqueostomy to be operated, that is why every second that we can save during the surgery is important. The normal exams as X rays and simple TAC give as an important idea but no complete, on the contrary the three-dimensional TAC permits to observe every damages and its exact location, this contribute to make a better surgery organization, the number and type of plates that we have to put and the better way to treat each case, that contribute to reduce time in operating theatre which is in benefit of the patient, diminishing risks in serious patients as they are, that is why we recommend the utilization of the three-dimensional TAC. (The author)

  16. Canonical and symplectic analysis for three dimensional gravity without dynamics

    International Nuclear Information System (INIS)

    Escalante, Alberto; Osmart Ochoa-Gutiérrez, H.

    2017-01-01

    In this paper a detailed Hamiltonian analysis of three-dimensional gravity without dynamics proposed by V. Hussain is performed. We report the complete structure of the constraints and the Dirac brackets are explicitly computed. In addition, the Faddeev–Jackiw symplectic approach is developed; we report the complete set of Faddeev–Jackiw constraints and the generalized brackets, then we show that the Dirac and the generalized Faddeev–Jackiw brackets coincide to each other. Finally, the similarities and advantages between Faddeev–Jackiw and Dirac’s formalism are briefly discussed. - Highlights: • We report the symplectic analysis for three dimensional gravity without dynamics. • We report the Faddeev–Jackiw constraints. • A pure Dirac’s analysis is performed. • The complete structure of Dirac’s constraints is reported. • We show that symplectic and Dirac’s brackets coincide to each other.

  17. Canonical and symplectic analysis for three dimensional gravity without dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Escalante, Alberto, E-mail: aescalan@ifuap.buap.mx [Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado Postal J-48 72570, Puebla, Pue. (Mexico); Osmart Ochoa-Gutiérrez, H. [Facultad de Ciencias Físico Matemáticas, Benemérita Universidad Autónoma de Puebla, Apartado postal 1152, 72001 Puebla, Pue. (Mexico)

    2017-03-15

    In this paper a detailed Hamiltonian analysis of three-dimensional gravity without dynamics proposed by V. Hussain is performed. We report the complete structure of the constraints and the Dirac brackets are explicitly computed. In addition, the Faddeev–Jackiw symplectic approach is developed; we report the complete set of Faddeev–Jackiw constraints and the generalized brackets, then we show that the Dirac and the generalized Faddeev–Jackiw brackets coincide to each other. Finally, the similarities and advantages between Faddeev–Jackiw and Dirac’s formalism are briefly discussed. - Highlights: • We report the symplectic analysis for three dimensional gravity without dynamics. • We report the Faddeev–Jackiw constraints. • A pure Dirac’s analysis is performed. • The complete structure of Dirac’s constraints is reported. • We show that symplectic and Dirac’s brackets coincide to each other.

  18. Handwriting: three-dimensional kinetic synergies in circle drawing movements.

    Science.gov (United States)

    Hooke, Alexander W; Karol, Sohit; Park, Jaebum; Kim, Yoon Hyuk; Shim, Jae Kun

    2012-07-01

    The purpose of this study was to investigate central nervous system (CNS) strategies for controlling multifinger forces during a circle-drawing task. Subjects drew 30 concentric, discontinuous clockwise and counter clockwise circles, at self and experimenter-set paces. The three-dimensional trajectory of the pen's center of mass and the three-dimensional forces and moments of force at each contact between the hand and the pen were recorded. Uncontrolled Manifold Analysis was used to quantify the synergies between pen-hand contact forces in radial, tangential and vertical directions. Results showed that synergies in the radial and tangential components were significantly stronger than in the vertical component. Synergies in the clockwise direction were significantly stronger than the counterclockwise direction in the radial and vertical components. Pace was found to be insignificant under any condition.

  19. Secondary instability and transition in three-dimensional boundary layers

    Energy Technology Data Exchange (ETDEWEB)

    Stolte, A.; Bertolotti, F.P.; Koch, W. (Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Goettingen (Germany). Inst. fuer Stroemungsmechanik)

    1999-01-01

    Stationary and traveling crossflow modes are the most prominent disturbances in the highly accelerated three-dimensional flow near the leading edge of a swept wing. Near transition onset, secondary three-dimensional instabilities of high frequency can be observed in such flows. A model flow on the basis of a DLR swept plate experiment allows a detailed study of transition scenarios triggered by crossflow instabilities, since the favorable pressure gradient over the whole plate inhibits instabilities of Tollmien-Schlichting type. In order to shed some light upon the role of the high-frequency secondary instabilities, the saturation characteristics of crossflow vortices in this model flow are investigated using the parabolized stability equations. In contrast to nonlinear equilibrium solutions of steady crossflow vortices, the nonlinear Polarized Stability Equations (PSE) results yield different maximal disturbance amplitudes for different initial amplitudes. (orig./AKF)

  20. Secondary instability and transition in three-dimensional boundary layers

    Energy Technology Data Exchange (ETDEWEB)

    Stolte, A.; Bertolotti, F.P.; Koch, W. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Goettingen (Germany). Inst. fuer Stroemungsmechanik

    1999-12-01

    Stationary and traveling crossflow modes are the most prominent disturbances in the highly accelerated three-dimensional flow near the leading edge of a swept wing. Near transition onset, secondary three-dimensional instabilities of high frequency can be observed in such flows. A model flow on the basis of a DLR swept plate experiment allows a detailed study of transition scenarios triggered by crossflow instabilities, since the favorable pressure gradient over the whole plate inhibits instabilities of Tollmien-Schlichting type. In order to shed some light upon the role of the high-frequency secondary instabilities, the saturation characteristics of crossflow vortices in this model flow are investigated using the parabolized stability equations. In contrast to nonlinear equilibrium solutions of steady crossflow vortices, the nonlinear Polarized Stability Equations (PSE) results yield different maximal disturbance amplitudes for different initial amplitudes. (orig./AKF)

  1. Two-dimensional turbulence in three-dimensional flows

    Science.gov (United States)

    Xia, H.; Francois, N.

    2017-11-01

    This paper presents a review of experiments performed in three-dimensional flows that show behaviour associated with two-dimensional turbulence. Experiments reveal the presence of the inverse energy cascade in two different systems, namely, flows in thick fluid layers driven electromagnetically and the Faraday wave driven flows. In thick fluid layers, large-scale coherent structures can shear off the vertical eddies and reinforce the planarity of the flow. Such structures are either self-generated or externally imposed. In the Faraday wave driven flows, a seemingly three-dimensional flow is shown to be actually two-dimensional when it is averaged over several Faraday wave periods. In this system, a coupling between the wave motion and 2D hydrodynamic turbulence is uncovered.

  2. Three-dimensional potential energy surface of Ar–CO

    Energy Technology Data Exchange (ETDEWEB)

    Sumiyoshi, Yoshihiro, E-mail: y-sumiyoshi@gunma-u.ac.jp [Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510 (Japan); Endo, Yasuki [Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan)

    2015-01-14

    A three-dimensional intermolecular potential energy surface of the Ar–CO complex has been determined by fitting most of the previously reported spectroscopic data, where observed transition frequencies by microwave, millimeter-wave, submillimeter-wave, and infrared spectroscopy were reproduced simultaneously within their experimental accuracies. A free rotor model Hamiltonian considering all the freedom of motions for an atom-diatom system was applied to calculate vibration-rotation energies. A three-dimensional potential energy surface obtained by ab initio calculations at the CCSD(T)-F12b/aug-cc-pV5Z level of theory was parameterized by a model function consisting of 46 parameters. They were used as initial values for the least-squares analysis of the experimental data. A total of 20 parameters were optimized to reproduce all the spectroscopic data.

  3. Three Dimensional Energy Transmitting Boundary in the Time Domain

    Directory of Open Access Journals (Sweden)

    Naohiro eNakamura

    2015-11-01

    Full Text Available Although the energy transmitting boundary is accurate and efficient for the FEM earthquake response analysis, it could be applied in the frequency domain only. In the previous papers, the author proposed an earthquake response analysis method using the time domain energy transmitting boundary for two dimensional problems. In this paper, this technique is expanded for three dimensional problems. The inner field is supposed to be a hexahedron shape and the approximate time domain boundary is explained, first. Next, two dimensional anti-plane time domain boundary is studied for a part of the approximate three dimensional boundary method. Then, accuracy and efficiency of the proposed method are confirmed by example problems.

  4. Scattering and conductance quantization in three-dimensional metal nanocontacts

    DEFF Research Database (Denmark)

    Brandbyge, Mads; Jacobsen, Karsten Wedel; Nørskov, Jens Kehlet

    1997-01-01

    The transmission through three-dimensional nanocontacts is calculated in the presence of localized scattering centers and boundary scattering using a coupled-channel recursion method. Simple confining potentials are used to investigate how robust the observation of quantized conductance is with r......The transmission through three-dimensional nanocontacts is calculated in the presence of localized scattering centers and boundary scattering using a coupled-channel recursion method. Simple confining potentials are used to investigate how robust the observation of quantized conductance...... is with respect to the scattering. We find that the quantum features are quite stable: the scattering by a localized scatterer will selectively smear and downshift certain quantum steps depending on the position of the scatterer, but the remaining steps will. still be at integer positions. The effect...

  5. Single florescent nanodiamond in a three dimensional ABEL trap

    Science.gov (United States)

    Kayci, Metin; Radenovic, Aleksandra

    2015-01-01

    Three dimensional single particle trapping and manipulation is an outstanding challenge in various fields ranging from basic physics to life sciences. By monitoring the response of a trapped particle to a designed environment one can extract its characteristics. In addition, quantum dynamics of a spatially scanned well-known particle can provide environmental information. Precise tracking and positioning of such a particle in aqueous environment is crucial task for achieving nano-scale resolution. Here we experimentally demonstrate three dimensional ABEL trap operating at high frequency by employing a hybrid approach in particle tracking. The particle location in the transverse plane is detected via a scanning laser beam while the axial position is determined by defocused imaging. The scanning of the trapped particle is accomplished through a nano positioning stage integrated to the trap platform. PMID:26559890

  6. Three-dimensional Microarchitecture of Adolescent Cancellous Bone

    DEFF Research Database (Denmark)

    Ding, Ming; Hvid, I; Overgaard, Søren

    regarding three-dimensional (3-D) microarchitecture of normal adolescent cancellous bone. The objective of this study was to investigate 3-D microarchitecture of normal adolescent cancellous bone, and compared them with adult cancellous bone, thus seeking more insight into the subchondral bone adaptations...... during development and growth. We hypothesized that adolescent cancellous bone differed significantly from adult cancellous bone in their microarchitecture and mechanical properties. METHODS: Twenty-three human proximal tibiae were harvested and divided into 3 groups according to their ages: adolescence...... of Orthopaedics & Traumatology and Institute of Forensic Medicine, Odense and Aarhus University Hospitals, Denmark. RESULTS: Three-dimensional reconstructions of cancellous bone from micro-CT imaging are shown in Figure 1. Our data showed that trabecular separation was significantly greater in the adolescence...

  7. Study of three-dimensional effects on vortex breakdown

    Science.gov (United States)

    Salas, M. D.; Kuruvila, G.

    1988-01-01

    The incompressible axisymmetric steady Navier-Stokes equations in primitive variables are used to simulate vortex breakdown. The equations, discretized using a second-order, central-difference scheme, are linearized and then solved using an exact LU decomposition, Gaussian elimination, and Newton iteration. Solutions are presented for Reynolds numbers, based on vortex-core radius, as high as 1500. An attempt to study the stability of the axisymmetric solutions against three-dimensional perturbations is discussed.

  8. A three-dimensional model of women's empowerment

    OpenAIRE

    Huis, Marloes A.; Hansen, Nina; Otten, Sabine; Lensink, Robert

    2017-01-01

    Women's empowerment is an important goal in achieving sustainable development worldwide. Offering access to microfinance services to women is one way to increase women's empowerment. However, empirical evidence provides mixed results with respect to its effectiveness. We reviewed previous research on the impact of microfinance services on different aspects of women's empowerment. We propose a Three-Dimensional Model of Women's Empowerment to integrate previous findings and to gain a deeper un...

  9. Three Dimensional Unstructured Multigrid for the Euler Equations

    Science.gov (United States)

    1991-05-01

    represents an algorithmic issue. While much work has been performed in two dimensions on direct [21, iterative implicit [3,4,51, and multigrid methods [6,7,8...methods, and many of the iterative implicit methods incur too large memory overheads to be practical for three-dimensional problems. Multigrid methods , on...the Third Copper Mountain Confer- ence on Multigrid Methods , Lecture Notes in Pure and Applied Mathematics, Ed S. F. McCormick, Marcel Dckker Inc

  10. Three-dimensional discrete ordinates reactor assembly calculations on GPUs

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Thomas M [ORNL; Joubert, Wayne [ORNL; Hamilton, Steven P [ORNL; Johnson, Seth R [ORNL; Turner, John A [ORNL; Davidson, Gregory G [ORNL; Pandya, Tara M [ORNL

    2015-01-01

    In this paper we describe and demonstrate a discrete ordinates sweep algorithm on GPUs. This sweep algorithm is nested within a multilevel comunication-based decomposition based on energy. We demonstrated the effectiveness of this algorithm on detailed three-dimensional critical experiments and PWR lattice problems. For these problems we show improvement factors of 4 6 over conventional communication-based, CPU-only sweeps. These sweep kernel speedups resulted in a factor of 2 total time-to-solution improvement.

  11. Three-dimensional transparent parabolic concentrator for photovoltaics

    OpenAIRE

    Huichuan Lin; Peng Xie; Yong Liu; Xiang Zhou; Baojun Li

    2015-01-01

    A three-dimensional transparent parabolic concentrator made of polymethylmethacrylate (PMMA) was designed and fabricated for photovoltaic applications. The measured maximum concentration ratio of the concentrator is 8.31, which means that for normal incident light, optical energy can be concentrated as high as 8.31 times by the concentrator. Even for oblique incident lights with an incident angle of between 5° and 15°, the concentrator maintains a concentration ratio of between 6.81 and 3.72....

  12. Aerodynamics of Airfoils Subject to Three-Dimensional Periodic Gusts.

    Science.gov (United States)

    1983-08-31

    and computational procedures to calculate the unsteady forces acting upon airfoils of arbitrary shape subject to three-dimensional gust disturbances...However the mathenatical formulation which has evolved from our analytical work can also be applied under certain conditions to study the changes in...check the validity of our computation scheme two sets of comparisons were carried out. First we considered a two-dimensional gust with transverse and

  13. Environmental, Transient, Three-Dimensional, Hydrothermal, Mass Transport Code - FLESCOT

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yasuo [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bao, Jie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glass, Kevin A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Eyler, L. L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Okumura, Masahiko [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-28

    The purpose of the project was to modify and apply the transient, three-dimensional FLESCOT code to be able to effectively simulate cesium behavior in Fukushima lakes/dam reservoirs, river mouths, and coastal areas. The ultimate objective of the FLESCOT simulation is to predict future changes of cesium accumulation in Fukushima area reservoirs and costal water. These evaluation results will assist ongoing and future environmental remediation activities and policies in a systematic and comprehensive manner.

  14. Heat engine in the three-dimensional spacetime

    International Nuclear Information System (INIS)

    Mo, Jie-Xiong; Liang, Feng; Li, Gu-Qiang

    2017-01-01

    We define a kind of heat engine via three-dimensional charged BTZ black holes. This case is quite subtle and needs to be more careful. The heat flow along the isochores does not equal to zero since the specific heat C V ≠0 and this point completely differs from the cases discussed before whose isochores and adiabats are identical. So one cannot simply apply the paradigm in the former literatures. However, if one introduces a new thermodynamic parameter associated with the renormalization length scale, the above problem can be solved. We obtain the analytical efficiency expression of the three-dimensional charged BTZ black hole heat engine for two different schemes. Moreover, we double check with the exact formula. Our result presents the first specific example for the sound correctness of the exact efficiency formula. We argue that the three-dimensional charged BTZ black hole can be viewed as a toy model for further investigation of holographic heat engine. Furthermore, we compare our result with that of the Carnot cycle and extend the former result to three-dimensional spacetime. In this sense, the result in this paper would be complementary to those obtained in four-dimensional spacetime or ever higher. Last but not the least, the heat engine efficiency discussed in this paper may serve as a criterion to discriminate the two thermodynamic approaches introduced in ref. https://www.doi.org/10.1103/PhysRevD.92.124069 and our result seems to support the approach which introduces a new thermodynamic parameter R=r 0 .

  15. Three dimensional Green's function for ship motion at forward speed

    Directory of Open Access Journals (Sweden)

    Matiur Rahman

    1990-01-01

    Full Text Available The Green's function formulation for ship motion at forward speed contains double integrals with singularities in the path of integrations with respect to the wave number. In this study, the double integrals have been replaced by single integrals with the use of complex exponential integrals. It has been found that this analysis provides an efficient way of computing the wave resistance for three dimensional potential problem of ship motion with forward speed.

  16. Functional renormalization group for three-dimensional quantum magnetism

    Science.gov (United States)

    Iqbal, Yasir; Thomale, Ronny; Parisen Toldin, Francesco; Rachel, Stephan; Reuther, Johannes

    2016-10-01

    We formulate a pseudofermion functional renormalization group (PFFRG) scheme to address frustrated quantum magnetism in three dimensions. In a scenario where many numerical approaches fail due to sign problem or small system size, three-dimensional (3D) PFFRG allows for a quantitative investigation of the quantum spin problem and its observables. We illustrate 3D PFFRG for the simple cubic J1-J2-J3 quantum Heisenberg antiferromagnet, and benchmark it against other approaches, if available.

  17. Three dimensional refractive index imaging with differential interference contrast microscopy

    Science.gov (United States)

    Aung, Htet; Buckley, Jared; Kostyk, Piotr; Rodriguez, Braulio; Phelan, Shelley; Xu, M.

    2012-03-01

    We report here a new approach based on an extension of the transport of the intensity equation for three dimensional refractive index imaging of a weak phase object from a series of images recorded by a differential interference contrast microscope at different focus (z-stack). Our method is first validated by imaging polystyrene spheres. We then apply this method to monitor in vivo apoptosis of human breast MCF7 epithelial cells. The potential applications are discussed at the end.

  18. Three-dimensional friction measurement during hip simulation.

    Directory of Open Access Journals (Sweden)

    Robert Sonntag

    Full Text Available Wear of total hip replacements has been the focus of many studies. However, frictional effects, such as high loading on intramodular connections or the interface to the bone, as well as friction associated squeaking have recently increased interest about the amount of friction that is generated during daily activities. The aim of this study was thus to establish and validate a three-dimensional friction setup under standardized conditions.A standard hip simulator was modified to allow for high precision measurements of small frictional effects in the hip during three-dimensional hip articulation. The setup was verified by an ideal hydrostatic bearing and validated with a static-load physical pendulum and an extension-flexion rotation with a dynamic load profile. Additionally, a pendulum model was proposed for screening measurement of frictional effects based on the damping behavior of the angular oscillation without the need for any force/moment transducer. Finally, three-dimensional friction measurements have been realized for ceramic-on-polyethylene bearings of three different sizes (28, 36 and 40 mm.A precision of less than 0.2 Nm during three-dimensional friction measurements was reported, while increased frictional torque (resultant as well as taper torque was measured for larger head diameters. These effects have been confirmed by simple pendulum tests and the theoretical model. A comparison with current literature about friction measurements is presented.This investigation of friction is able to provide more information about a field that has been dominated by the reduction of wear. It should be considered in future pre-clinical testing protocols given by international organizations of standardization.

  19. Three-dimensional reconstruction of the otosclerotic focus

    DEFF Research Database (Denmark)

    Bloch, Sune Land; Sørensen, Mads Sølvsten

    2010-01-01

    The location and three-dimensional (3D) shapes of the otosclerotic foci suggest a general centripetal distribution of otosclerotic bone remodeling around the inner ear space, whereas the normal bone remodeling is distributed centrifugally. The existence of an inverse spatial relation between norm...... and otosclerotic bone remodeling suggests that inner ear mechanisms in control of bone remodeling may have a pathogenetic role in otosclerosis....

  20. Heat engine in the three-dimensional spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Jie-Xiong [Institute of Theoretical Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China); Department of Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China); Liang, Feng [Department of Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China); Li, Gu-Qiang [Institute of Theoretical Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China); Department of Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China)

    2017-03-02

    We define a kind of heat engine via three-dimensional charged BTZ black holes. This case is quite subtle and needs to be more careful. The heat flow along the isochores does not equal to zero since the specific heat C{sub V}≠0 and this point completely differs from the cases discussed before whose isochores and adiabats are identical. So one cannot simply apply the paradigm in the former literatures. However, if one introduces a new thermodynamic parameter associated with the renormalization length scale, the above problem can be solved. We obtain the analytical efficiency expression of the three-dimensional charged BTZ black hole heat engine for two different schemes. Moreover, we double check with the exact formula. Our result presents the first specific example for the sound correctness of the exact efficiency formula. We argue that the three-dimensional charged BTZ black hole can be viewed as a toy model for further investigation of holographic heat engine. Furthermore, we compare our result with that of the Carnot cycle and extend the former result to three-dimensional spacetime. In this sense, the result in this paper would be complementary to those obtained in four-dimensional spacetime or ever higher. Last but not the least, the heat engine efficiency discussed in this paper may serve as a criterion to discriminate the two thermodynamic approaches introduced in ref. https://www.doi.org/10.1103/PhysRevD.92.124069 and our result seems to support the approach which introduces a new thermodynamic parameter R=r{sub 0}.

  1. Three-dimensional, computer simulated navigation in endoscopic neurosurgery

    Directory of Open Access Journals (Sweden)

    Roberta K. Sefcik, BHA

    2017-06-01

    Conclusion: Three-dimensional, frameless neuronavigation systems are useful in endoscopic neurosurgery to assist in the pre-operative planning of potential trajectories and to help localize the pathology of interest. Neuronavigation appears to be accurate to <1–2 mm without issues related to brain shift. Further work is necessary in the investigation of the effect of neuronavigation on operative time, cost, and patient-centered outcomes.

  2. Accuracy of three-dimensional printing for manufacturing replica teeth

    OpenAIRE

    Lee, Keun-Young; Cho, Jin-Woo; Chang, Na-Young; Chae, Jong-Moon; Kang, Kyung-Hwa; Kim, Sang-Cheol; Cho, Jin-Hyoung

    2015-01-01

    Objective Three-dimensional (3D) printing is a recent technological development that may play a significant role in orthodontic diagnosis and treatment. It can be used to fabricate skull models or study models, as well as to make replica teeth in autotransplantation or tooth impaction cases. The aim of this study was to evaluate the accuracy of fabrication of replica teeth made by two types of 3D printing technologies. Methods Fifty extracted molar teeth were selected as samples. They were sc...

  3. Is a three-dimensional-printed tooth filling possible?

    OpenAIRE

    Muhammet Kerim Ayar

    2016-01-01

    Introduction: Three-dimensional (3-D) printing is seen as an innovative production process in many fields of dentistry and medicine. But implantation of this novel production process into the treatment of decayed teeth in dentistry remains lacking. Destruction of dental tissues as a result of dental caries is generally treated with dental resin composite fillings. However, a 3-D-printed tooth filling approach, which could be an alternative to traditional approaches, has a potential to reduce ...

  4. Three-dimensional fluorescence characteristics of white chrysanthemum flowers

    Science.gov (United States)

    Fan, Yunchang; Li, Yang; Cai, Hongxin; Li, Jing; Miao, Juan; Fu, Dexue; Su, Kun

    2014-09-01

    White chrysanthemum flower is one of the most popular plants found everywhere in China and used as herbs. In the present work, three-dimensional fluorescence technique was used to discriminate species of white chrysanthemum flowers. Parameters affecting extraction efficiency were investigated. Under the optimal conditions, the three-dimensional fluorescence characteristics of three types of white chrysanthemum flowers were obtained. It was found that there were two main fluorescence peaks with remarkable difference in fluorescence intensity, one was corresponding to flavonoids and another was attributed to chlorophyll-like compounds. There were remarkable differences among the contours of the three white chrysanthemum flowers. Further studies showed that the fluorescence intensity ratios of chlorophyll-like compounds to flavonoids had a certain relationship with the species; those for Huai, Hang and Huangshan white chrysanthemum flowers were 6.9-7.4, 18.9-21.4 and 73.6-84.5, respectively. All of the results suggest that three-dimensional fluorescence spectra can be used for the discrimination of white chrysanthemum flowers with the advantages of low cost, ease for operation and intuition.

  5. Surface image of herniated disc on three-dimensional CT

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Kyung Il; Jeon, Chang Hoon; Kim, Sun Yong; Kim, Ok Hwa; Suh, Jung Ho [Ajou Univ. College of Medicine, Suwon(Korea, Republic of)

    1996-03-01

    To evaluate surface configuration of herniated disc on three-dimensional CT. Three dimensional surface images reconstructed from CT scans(1 mm thick) of 24 surgically confirmed herniated discs in 23 patients were reviewed. Disc surface was classified into peripheral and central zones in contact with consecutive peripheral ring and central endplate. Surface irregularity was categorized into two types(local and general). The incidence, size, and extent of local irregularity were observed. General irregularity incidence and severity ranges in 4 grades, and peripheral width were evaluated. The findings were correlated with discography. Local irregularity compatible with anulus tear in discography was shown in all. It was large(13/24) and mainly peripheral tract extending to disc margin in protrusion(3/5) and sequestration(5/7), and cleft encompassing central zone to disc margin in extrusion(9/12). General irregularity was predominantly grade 3(15/22) and was shown in all except in 2 protrusions. Peripheral width was 0.56 of central radius. Extrusion in herniated disc shows characteristic cleft encompassing central zone to disc margin whereas sequestration or protrusion displays tract extending from peripheral zone to disc margin. Thus, three dimensional surface imaging may aid the diagnosis, follow-up, prediction, and treatment of herniated disc.

  6. Comparison of two three-dimensional cephalometric analysis computer software.

    Science.gov (United States)

    Sawchuk, Dena; Alhadlaq, Adel; Alkhadra, Thamer; Carlyle, Terry D; Kusnoto, Budi; El-Bialy, Tarek

    2014-10-01

    Three-dimensional cephalometric analyses are getting more attraction in orthodontics. The aim of this study was to compare two softwares to evaluate three-dimensional cephalometric analyses of orthodontic treatment outcomes. Twenty cone beam computed tomography images were obtained using i-CAT(®) imaging system from patient's records as part of their regular orthodontic records. The images were analyzed using InVivoDental5.0 (Anatomage Inc.) and 3DCeph™ (University of Illinois at Chicago, Chicago, IL, USA) software. Before and after orthodontic treatments data were analyzed using t-test. Reliability test using interclass correlation coefficient was stronger for InVivoDental5.0 (0.83-0.98) compared with 3DCeph™ (0.51-0.90). Paired t-test comparison of the two softwares shows no statistical significant difference in the measurements made in the two softwares. InVivoDental5.0 measurements are more reproducible and user friendly when compared to 3DCeph™. No statistical difference between the two softwares in linear or angular measurements. 3DCeph™ is more time-consuming in performing three-dimensional analysis compared with InVivoDental5.0.

  7. Space charge cartography by FLIMM: a three-dimensional approach

    International Nuclear Information System (INIS)

    Marty-Dessus, D; Berquez, L; Petre, A; Franceschi, J L

    2002-01-01

    A technique for three-dimensional cartography of space charges profiles inside polymer insulating samples is proposed. Called focused laser intensity modulation method (FLIMM), it is derived from the well-known LIMM method, with an additional possibility of being able to focus the laser spot on the surface of the sample to be studied. The processed data is a short-circuited pyrolectric current collected between the electrodes and induced by the interaction of the charges with the periodic variations of temperature produced by the laser source. The focused aspect of our method requires a good three-dimensional modelling of the spatial evolution of this thermal gradient. Under these conditions, the treatment of the equation of heat propagation is carried out using simultaneously a double Fourier transform and Green functions. In association with the numerical simulations of this solution, a two-dimensional scanning of the beam on polyethylene test sample surfaces shows that one can get three-dimensional representations of space charge shapes with a lateral resolution lower than 10 μm and for a depth of analysis typically included in the range 1-100 μm

  8. Nonlinear three-dimensional trajectory following: simulation and application

    Science.gov (United States)

    Hines, George H.

    In light of recent military requirements for unmanned and autonomous vehicles, research into methods of designing arbitrary three-dimensional trajectories and controlling aircraft along them has become vital. In this report, we explore two methods of nonlinear control for the purpose of following three-dimensional trajectories and paths. First, prior work on a dynamic feedback linearization exploiting the differential flatness of the ideal airplane is adapted with the intent of implementing it on a physical testbed in MIT's Realtime indoor Autonomous Vehicle test ENvironment (RAVEN), but poor behavior—both in simulation and in hardware—under moderate levels of joint parameter uncertainty thwarted attempts at implementation. Additionally, the differential flatness technique in its pure form follows trajectories, which are sometimes inferior intuitively and practically to paths. In the context of unmanned air vehicle (UAV) flight in gusty environments, this motivated the extension of prior work on two-dimensional path following to three-dimensions, and simulations are presented in which the fully nonlinear controller derived from differential flatness follows a trajectory that is generated dynamically from a path. The three-dimensional path-following logic is actually implemented in RAVEN, and results are presented that demonstrate good vertical rise time in response to a step input and centimeter accuracy in vertical and lateral tracking. Future directions are proposed.

  9. Three dimensional finite element methods: Their role in the design of DC accelerator systems

    Energy Technology Data Exchange (ETDEWEB)

    Podaru, Nicolae C.; Gottdang, A.; Mous, D. J. W. [High Voltage Engineering Europa B.V., P.O. Box 99, 3800 AB, Amersfoort (Netherlands)

    2013-04-19

    High Voltage Engineering has designed, built and tested a 2 MV dual irradiation system that will be applied for radiation damage studies and ion beam material modification. The system consists of two independent accelerators which support simultaneous proton and electron irradiation (energy range 100 keV - 2 MeV) of target sizes of up to 300 Multiplication-Sign 300 mm{sup 2}. Three dimensional finite element methods were used in the design of various parts of the system. The electrostatic solver was used to quantify essential parameters of the solid-state power supply generating the DC high voltage. The magnetostatic solver and ray tracing were used to optimize the electron/ion beam transport. Close agreement between design and measurements of the accelerator characteristics as well as beam performance indicate the usefulness of three dimensional finite element methods during accelerator system design.

  10. Mapping of strain mechanisms in barium titanate by three-dimensional X-ray diffraction

    DEFF Research Database (Denmark)

    Majkut, Marta

    This thesis presents an in-situ three-dimensional study of the grain-scale response of a prototypical piezoelectric ceramic, barium titanate (BT), to an exernally applied electric field. Piezoceramics take advantage of the coupling of electrical and mechanical energies for use in sensors and actu......This thesis presents an in-situ three-dimensional study of the grain-scale response of a prototypical piezoelectric ceramic, barium titanate (BT), to an exernally applied electric field. Piezoceramics take advantage of the coupling of electrical and mechanical energies for use in sensors...... to study the material at the grain scale. First, we use the intensity ratios of split diffraction peaks to extract grain-scale domain volume fractions for 139 grains. We find that even in the as-processed state there exist unequal volume fractions of each domain type, which we attribute to a heterogeneous...

  11. Evaluation of oral scanning in comparison to impression using three-dimensional registration

    Science.gov (United States)

    Brogle-Kim, Yur-Chung; Deyhle, Hans; Müller, Bert; Schulz, Georg; Bormann, Therese; Beckmann, Felix; Jäger, Kurt

    2012-10-01

    Crown and bridge restorations are one of the main treatment methods in fixed prosthodontics. The fabrication requires data on the patient's denture shape. This information is generally obtained as a hard copy from an impression mold. Alternatively, one can acquire the data electronically using oral optical three-dimensional (3D) imaging techniques, which determine the surface of the denture. The aim of the study was to quantitatively compare the accuracy of three dimensional scanning with that of conventional impressions and give a statement how far the scanner provides a clinical alternative with equal or better precision. Data from 10 teeth were acquired in the dental office with a polyether impression material and an oral scanner. Data from the impressions were digitalized by means of micro computed tomography. The data were then 3D registered to identify the potential differences between impression and optical scan. We could demonstrate that the oral scanner's data and the conventional impressions are comparable.

  12. Progress in the preparation and application of three-dimensional graphene-based porous nanocomposites

    Science.gov (United States)

    Yan, Zhengquan; Yao, Wenli; Hu, Lei; Liu, Dandan; Wang, Chundong; Lee, Chun-Sing

    2015-03-01

    Due to high specific surface area, excellent conductivity, low mass density, good compatibility and elegant flexibility, three-dimensional graphene composites with interconnected porous structures possess unusual and novel physical and electronic properties, unsurpassed chemical functionalities and other attractive features. Therefore, different three-dimensional graphene-based nanoporous scaffolds have been extensively designed, prepared and investigated for practical applications in lithium-ion batteries, super-capacitors, solar cells, catalysis, thermal management, environment pollution enrichment and separation, and chemical sensors with high performance from both fundamental and technological viewpoints. To present readers with a better understanding of this kind of important porous material, in this feature article, we will highlight the main achievements made in the preparation of 3D graphene micro- and/or nano-architectures and their potential applications in the aforementioned fields.

  13. Magnetic field induced strong valley polarization in the three-dimensional topological semimetal LaBi

    Science.gov (United States)

    Kumar, Nitesh; Shekhar, Chandra; Klotz, J.; Wosnitza, J.; Felser, Claudia

    2017-10-01

    LaBi is a three-dimensional rocksalt-type material with a surprisingly quasi-two-dimensional electronic structure. It exhibits excellent electronic properties such as the existence of nontrivial Dirac cones, extremely large magnetoresistance, and high charge-carrier mobility. The cigar-shaped electron valleys make the charge transport highly anisotropic when the magnetic field is varied from one crystallographic axis to another. We show that the electrons can be polarized effectively in these electron valleys under a rotating magnetic field. We achieved a polarization of 60% at 2 K despite the coexistence of three-dimensional hole pockets. The valley polarization in LaBi is compared to the sister compound LaSb where it is found to be smaller. The performance of LaBi is comparable to the highly efficient bismuth.

  14. Estimation of the standard deviation in three-dimensional microscopy by spatial statistics.

    Science.gov (United States)

    Sanchez-Brea, L M; Bernabeu, E

    2005-05-01

    Usually, the calibration process for three-dimensional microscopy involves the use of a reference flat surface. The random fluctuations of the topographic image for this reference surface are used for determining the uncertainty of the microscope. When the sample material or the measuring conditions of the microscope are modified (such as the objective used in a confocal microscope, or the tip in an atomic force microscope), the measuring conditions vary and thus a new calibration is required. In this work, a technique based on spatial statistics methods (more specifically, the variogram function) is proposed to determine accurately the standard deviation for three-dimensional microscopy that does not require a reference flat surface and therefore eliminates the need for a previous calibration process of this parameter.

  15. Three-dimensional microstructural effects on plane strain ductile crack growth

    DEFF Research Database (Denmark)

    Tvergaard, Viggo; Needleman, Alan

    2006-01-01

    Ductile crack growth under mode 1, plane strain, small scale yielding conditions is analyzed. Overall plane strain loading is prescribed, but a full 3D analysis is carried out to model three dimensional microstructural effects. An elastic-viscoplastic constitutive relation for a porous plastic...... solid is used to model the material. Two populations of secondphase particles are represented, large inclusions with low strength, which result in large voids near the crack tip at an early stage, and small second-phase particles, which require large strains before cavities nucleate. The larger...... inclusions are represented discretely and the effects of different three dimensional distributions on the crack path and on the overall crack growth rate are analyzed. For comparison purposes, a two dimensional distribution of cylindrical inclusions is analyzed. Crack growth occurs off the initial crack...

  16. Progress in the preparation and application of three-dimensional graphene-based porous nanocomposites.

    Science.gov (United States)

    Yan, Zhengquan; Yao, Wenli; Hu, Lei; Liu, Dandan; Wang, Chundong; Lee, Chun-Sing

    2015-03-19

    Due to high specific surface area, excellent conductivity, low mass density, good compatibility and elegant flexibility, three-dimensional graphene composites with interconnected porous structures possess unusual and novel physical and electronic properties, unsurpassed chemical functionalities and other attractive features. Therefore, different three-dimensional graphene-based nanoporous scaffolds have been extensively designed, prepared and investigated for practical applications in lithium-ion batteries, super-capacitors, solar cells, catalysis, thermal management, environment pollution enrichment and separation, and chemical sensors with high performance from both fundamental and technological viewpoints. To present readers with a better understanding of this kind of important porous material, in this feature article, we will highlight the main achievements made in the preparation of 3D graphene micro- and/or nano-architectures and their potential applications in the aforementioned fields.

  17. Terahertz computed tomography in three-dimensional using a pyroelectric array detector

    Science.gov (United States)

    Li, Bin; Wang, Dayong; Zhou, Xun; Rong, Lu; Huang, Haochong; Wan, Min; Wang, Yunxin

    2017-05-01

    Terahertz frequency range spans from 0.1 to 10 THz. Terahertz radiation can penetrate nonpolar materials and nonmetallic materials, such as plastics, wood, and clothes. Then the feature makes the terahertz imaging have important research value. Terahertz computed tomography makes use of the penetrability of terahertz radiation and obtains three-dimensional object projection data. In the paper, continuous-wave terahertz computed tomography with a pyroelectric array detectoris presented. Compared with scanning terahertz computed tomography, a pyroelectric array detector can obtain a large number of projection data in a short time, as the acquisition mode of the array pyroelectric detector omit the projection process on the vertical and horizontal direction. With the two-dimensional cross-sectional images of the object are obtained by the filtered back projection algorithm. The two side distance of the straw wall account for 80 pixels, so it multiplied by the pixel size is equal to the diameter of the straw about 6.4 mm. Compared with the actual diameter of the straw, the relative error is 6%. In order to reconstruct the three-dimensional internal structure image of the straw, the y direction range from 70 to 150 are selected on the array pyroelectric detector and are reconstructed by the filtered back projection algorithm. As the pixel size is 80 μm, the height of three-dimensional internal structure image of the straw is 6.48 mm. The presented system can rapidly reconstruct the three-dimensional object by using a pyroelectric array detector and explores the feasibility of on non-destructive evaluation and security testing.

  18. Investigation of the effects of type of crusher on coarse aggregates shape properties using three-dimensional Laser Scanning Technique

    CSIR Research Space (South Africa)

    Komba, Julius J

    2016-07-01

    Full Text Available materials and therefore performance. Recent studies have demonstrated that laser scanning technique can be employed to better quantify the three-dimensional (3- D) shape properties of aggregate materials used in pavements. In this paper, the shape properties...

  19. Three-dimensional appearance of the lips muscles with three-dimensional isotropic MRI: in vivo study.

    Science.gov (United States)

    Olszewski, Raphael; Liu, Y; Duprez, T; Xu, T M; Reychler, H

    2009-06-01

    Our knowledge of facial muscles is based primarily on atlases and cadaveric studies. This study describes a non-invasive in vivo method (3D MRI) for segmenting and reconstructing facial muscles in a three-dimensional fashion. Three-dimensional (3D), T1-weighted, 3 Tesla, isotropic MRI was applied to a subject. One observer performed semi-automatic segmentation using the Editor module from the 3D Slicer software (Harvard Medical School, Boston, MA, USA), version 3.2. We were able to successfully outline and three-dimensionally reconstruct the following facial muscles: pars labialis orbicularis oris, m. levatro labii superioris alaeque nasi, m. levator labii superioris, m. zygomaticus major and minor, m. depressor anguli oris, m. depressor labii inferioris, m. mentalis, m. buccinator, and m. orbicularis oculi. 3D reconstruction of the lip muscles should be taken into consideration in order to improve the accuracy and individualization of existing 3D facial soft tissue models. More studies are needed to further develop efficient methods for segmentation in this field.

  20. Studies on three-dimensional reproduction of maxillofacial cranium shape, 2

    International Nuclear Information System (INIS)

    Mihara, Manabu

    1984-01-01

    The purpose of the serial studies were to develop a three-dimensional reproduction for diagnosis and surgical therapy planning. In the present study, the author devised the methd of making models reproduced through applying high resolutional computed tomography (GE CT/T). Preliminary examinations were carried out on the CT numbers and on the measurement of CT film images for three-dimensional reproduction. The results are summarized below: 1) There were few hourly changes of CT numbers. 2) At the interspace of the phantom teflon rod and water, CT numbers changed gradually because of the partial volume effect and the edge response. Although the true boundaries of the materials could be indentified with the median CT number of the two substances. 3) Setting up to 1,000 on the window level and 1,200 on the window width, the measurement value of the views of the phantom teflon rod which had been magnified 1.8 power coincided with the true size. 4) Supplementary examinations were carried out on the same methods using a pig mandible, and the results were affirmed. The models were made of acrilic boards which the images of CT films were traced. Those boards were waxed up and trimmed in the boxies for three-dimensional reproduction by using cephalograms. The reproducible accuracy of the completed models was satisfactory for use in the field of the maxillofacial surgery. (author)

  1. Oil adsorption ability of three-dimensional epicuticular wax coverages in plants

    Science.gov (United States)

    Gorb, Elena V.; Hofmann, Philipp; Filippov, Alexander E.; Gorb, Stanislav N.

    2017-04-01

    Primary aerial surfaces of terrestrial plants are very often covered with three-dimensional epicuticular waxes. Such wax coverages play an important role in insect-plant interactions. Wax blooms have been experimentally shown in numerous previous studies to be impeding locomotion and reducing attachment of insects. Among the mechanisms responsible for these effects, a possible adsorption of insect adhesive fluid by highly porous wax coverage has been proposed (adsorption hypothesis). Recently, a great decrease in insect attachment force on artificial adsorbing materials was revealed in a few studies. However, adsorption ability of plant wax blooms was still not tested. Using a cryo scanning electron microscopy approach and high-speed video recordings of fluid drops behavior, followed by numerical analysis of experimental data, we show here that the three-dimensional epicuticular wax coverage in the waxy zone of Nepenthes alata pitcher adsorbs oil: we detected changes in the base, height, and volume of the oil drops. The wax layer thickness, differing in samples with untreated two-layered wax coverage and treated one-layered wax, did not significantly affect the drop behavior. These results provide strong evidence that three-dimensional plant wax coverages due to their adsorption capability are in general anti-adhesive for insects, which rely on wet adhesion.

  2. Granular avalanches across irregular three-dimensional terrain: 2. Experimental tests

    Science.gov (United States)

    Iverson, Richard M.; Logan, Matthew; Denlinger, Roger P.

    2004-03-01

    Scaling considerations indicate that miniature experiments can be used to test models of granular avalanches in which the effects of intergranular fluid and cohesion are negligible. To test predictions of a granular avalanche model described in a companion paper, we performed bench top experiments involving avalanches of dry sand across irregular basal topography that mimicked the complexity of natural terrain. The experiments employed a novel method of laser-assisted cartography to map the three-dimensional morphology of rapidly moving avalanches, thereby providing high-resolution data for comparison with model output. Model input consisted of two material properties (angles of internal and basal Coulomb friction of the sand), which were measured in independent tests, and of initial and boundary conditions that characterized the geometry of the experimental apparatus. Experimental results demonstrate that the model accurately predicts not only the gross behavior but also many details of avalanche motion, from initiation to deposition. We attribute this accuracy to a mathematical and computational formulation that conserves mass and momentum in three-dimensional physical space and satisfies the Coulomb equation in three-dimensional stress space. Our results support the hypothesis that a Coulomb proportionality between shear and normal stresses applies in moderately rapid granular flows and that complicated constitutive postulates are unnecessary if momentum conservation is strictly enforced in continuum avalanche models. Furthermore, predictions of our Coulomb continuum model contrast with those of a Coulomb point mass model, illustrating the importance of multidimensional modeling and model testing.

  3. Turbulent heat transport in two- and three-dimensional temperature fields

    Energy Technology Data Exchange (ETDEWEB)

    Samaraweera, Don Sarath Abesiri [Univ. of California, Berkeley, CA (United States)

    1978-03-01

    A fundamental numerical study of turbulent heat and mass transport processes in two- and three-dimensional convective flows is presented. The model of turbulence employed is the type referred to as a second-order closure. In this scheme transport equations for all nonzero components of the Reynolds stress tensor, for the isotropic dissipation rate of turbulent kinetic energy, for all nonzero scalar flux tensor components and for the mean square scalar fluctuations are solved by a finite difference method along with the mean momentum and mean enthalpy (or concentration) equations. The model used for the stresses was developed earlier. Parallel ideas were utilised in obtaining a model for turbulent heat and mass transfer processes. The study has focused especially on the problem of nonaxisymmetric convective heat and mass transport in pipes, which arises when the boundary conditions are not axisymmetric. The few available experimental data on such situations have indicated anisotropy in effective diffusivities. To expand the available data base an experiment was conducted to obtain heat transfer measurements in strong three-dimensional heating conditions. Numerical procedures especially suitable for incorporation of second-order turbulent closure models have been developed. The effect of circumferential conduction in the tube material, which is influential in the asymmetric heating data currently available, was accounted for directly by extending the finite difference calculations into the pipe wall. The principal goal of predicting three-dimensional scalar transfer has been achieved.

  4. Multi-GPU hybrid programming accelerated three-dimensional phase-field model in binary alloy

    Directory of Open Access Journals (Sweden)

    Changsheng Zhu

    2018-03-01

    Full Text Available In the process of dendritic growth simulation, the computational efficiency and the problem scales have extremely important influence on simulation efficiency of three-dimensional phase-field model. Thus, seeking for high performance calculation method to improve the computational efficiency and to expand the problem scales has a great significance to the research of microstructure of the material. A high performance calculation method based on MPI+CUDA hybrid programming model is introduced. Multi-GPU is used to implement quantitative numerical simulations of three-dimensional phase-field model in binary alloy under the condition of multi-physical processes coupling. The acceleration effect of different GPU nodes on different calculation scales is explored. On the foundation of multi-GPU calculation model that has been introduced, two optimization schemes, Non-blocking communication optimization and overlap of MPI and GPU computing optimization, are proposed. The results of two optimization schemes and basic multi-GPU model are compared. The calculation results show that the use of multi-GPU calculation model can improve the computational efficiency of three-dimensional phase-field obviously, which is 13 times to single GPU, and the problem scales have been expanded to 8193. The feasibility of two optimization schemes is shown, and the overlap of MPI and GPU computing optimization has better performance, which is 1.7 times to basic multi-GPU model, when 21 GPUs are used.

  5. Multi-GPU hybrid programming accelerated three-dimensional phase-field model in binary alloy

    Science.gov (United States)

    Zhu, Changsheng; Liu, Jieqiong; Zhu, Mingfang; Feng, Li

    2018-03-01

    In the process of dendritic growth simulation, the computational efficiency and the problem scales have extremely important influence on simulation efficiency of three-dimensional phase-field model. Thus, seeking for high performance calculation method to improve the computational efficiency and to expand the problem scales has a great significance to the research of microstructure of the material. A high performance calculation method based on MPI+CUDA hybrid programming model is introduced. Multi-GPU is used to implement quantitative numerical simulations of three-dimensional phase-field model in binary alloy under the condition of multi-physical processes coupling. The acceleration effect of different GPU nodes on different calculation scales is explored. On the foundation of multi-GPU calculation model that has been introduced, two optimization schemes, Non-blocking communication optimization and overlap of MPI and GPU computing optimization, are proposed. The results of two optimization schemes and basic multi-GPU model are compared. The calculation results show that the use of multi-GPU calculation model can improve the computational efficiency of three-dimensional phase-field obviously, which is 13 times to single GPU, and the problem scales have been expanded to 8193. The feasibility of two optimization schemes is shown, and the overlap of MPI and GPU computing optimization has better performance, which is 1.7 times to basic multi-GPU model, when 21 GPUs are used.

  6. MRI of the lateral ankle ligaments: value of three-dimensional orientation

    International Nuclear Information System (INIS)

    Mayerhoefer, M.E.; Breitenseher, M.J.

    2003-01-01

    Purpose: To determine the three-dimensional orientation of the lateral ankle ligaments with MRI. Materials and Methods: Twenty healthy volunteers without previous injury to the ankle were included in the study. With the right ankle in the normal anatomic position stabilized in a splint, coronal T2-weighted spin-echo sequences (TSE) were obtained. The three-dimensional orientation was determined by placing paths through the ligaments and by measuring the angles between corresponding tangents and the three main imaging planes. Results: Using the calculated angles, full-length visualization of the lateral ligaments of the ankle was achieved. The angles deviating from the axial imaging plane were 18.0 degrees for the anterior talofibular ligament, 52.3 degrees for the calcaneofibular ligament and 28.2 degrees for the posterior talofibular ligament. Conclusion: MRI enables the exact determination of the three-dimensional orientation of the lateral ankle ligaments. Orienting the imaging planes according to the calculated angular deviation allows the full-length visualization of the ligaments and is the basis for optimal imaging of the lateral ankle ligaments. (orig.) [de

  7. [Three-dimensional finite element model of thoracolumbar spine with osteoporotic vertebral compression fracture].

    Science.gov (United States)

    Fei, Qi; Li, Qiu-jun; Yang, Yong; Li, Dong; Tang, Hai; Li, Jin-jun; Wang, Bing-qiang; Wang, Yi-peng

    2010-11-09

    To build a three-dimensional finite element model of thoracolumbar spine with osteoporotic vertebral compression fracture (OVCF) and analyze its biomechanical change. The T10-L2 segment data were obtained from computed tomography (CT) scans of an elderly female with a single T12 OVCF. A three-dimensional finite element model of thoracolumbar spine was constructed with the MIMICS and ABAQUS software. The model was composed of bony vertebrae, articulating facets, intervertebral disc and associated ligaments. The basic stress analysis of T10-L2 motion segment was made for different material properties of bone, ligaments and facet joints contacting frictional property. The stress on the annulus fiber, nucleus pulposus, endplate and facet joints under axial pressure (0.3 MPa, 1.0 MPa, 4.0 MPa) were analyzed. A three-dimensional finite element model of human T12-L2 motion segment had 617468 elements. And the stress was higher in vertebral body than posterior structure. The distribution of pressure stresses in intervertebral disc was asymmetrical. The stress increased with a rising axial pressure. 3D finite element model of thoracolumbar OVCF and adjacent segments are successfully established. The results of stress analysis are both feasible and reliable.

  8. Asymmetric three-dimensional topography over mantle plumes.

    Science.gov (United States)

    Burov, Evgueni; Gerya, Taras

    2014-09-04

    The role of mantle-lithosphere interactions in shaping surface topography has long been debated. In general, it is supposed that mantle plumes and vertical mantle flows result in axisymmetric, long-wavelength topography, which strongly differs from the generally asymmetric short-wavelength topography created by intraplate tectonic forces. However, identification of mantle-induced topography is difficult, especially in the continents. It can be argued therefore that complex brittle-ductile rheology and stratification of the continental lithosphere result in short-wavelength modulation and localization of deformation induced by mantle flow. This deformation should also be affected by far-field stresses and, hence, interplay with the 'tectonic' topography (for example, in the 'active/passive' rifting scenario). Testing these ideas requires fully coupled three-dimensional numerical modelling of mantle-lithosphere interactions, which so far has not been possible owing to the conceptual and technical limitations of earlier approaches. Here we present new, ultra-high-resolution, three-dimensional numerical experiments on topography over mantle plumes, incorporating a weakly pre-stressed (ultra-slow spreading), rheologically realistic lithosphere. The results show complex surface evolution, which is very different from the smooth, radially symmetric patterns usually assumed as the canonical surface signature of mantle upwellings. In particular, the topography exhibits strongly asymmetric, small-scale, three-dimensional features, which include narrow and wide rifts, flexural flank uplifts and fault structures. This suggests a dominant role for continental rheological structure and intra-plate stresses in controlling dynamic topography, mantle-lithosphere interactions, and continental break-up processes above mantle plumes.

  9. Three-dimensional trajectory optimization in constrained airspace

    Science.gov (United States)

    Dai, Ran

    This dissertation deals with the generation of three-dimensional optimized trajectory in constrained airspace. It expands the previously used two-dimensional aircraft model to a three-dimensional model and includes the consideration of complex airspace constraints not included in previous trajectory optimization studies. Two major branches of optimization methods, indirect and direct methods, are introduced and compared. Both of the methods are applied to solve a two-dimensional minimum-time-to-climb (MTTC) problem. The solution procedure is described in detail. Two traditional problems, the Brachistochrone problem and Zermelo's problem, are solved using the direct collocation and nonlinear programming method. Because analytical solutions to these problems are known. These solutions provide verification of the numerical methods. Three discretization methods, trapezoidal, Hermite-Simpson and Chebyshev Pseudospectral (CP) are introduced and applied to solve the Brachistochrone problem. The solutions obtained using these discretization methods are compared with the analytical results. An 3-D aircraft model with six state variables and two control variables are presented. Two primary trajectory optimization problems are considered using this model in the dissertation. One is to assume that the aircraft climbs up from sea level to a desired altitude in a square cross section cylinder of arbitrary height. Another is to intercept a constant velocity, constant altitude target in minimum time starting from sea level. Results of the optimal trajectories are compared with the results from the proportional navigation guidance law. Field of View constraint is finally considered in this interception problem. The CP discretization and nonlinear programming method is shown to have advantages over indirect methods in solving three-dimensional (3-D) trajectory optimization problems with multiple controls and complex constraints. Conclusions from both problems are presented and

  10. Lyapunov Schmidt reduction algorithm for three-dimensional discrete vortices

    Science.gov (United States)

    Lukas, Mike; Pelinovsky, Dmitry; Kevrekidis, P. G.

    2008-03-01

    We address the persistence and stability of three-dimensional vortex configurations in the discrete nonlinear Schrödinger equation and develop a symbolic package based on Wolfram’s MATHEMATICA for computations of the Lyapunov-Schmidt reduction method. The Lyapunov-Schmidt reduction method is a theoretical tool which enables us to study continuations and terminations of the discrete vortices for small coupling between lattice nodes as well as the spectral stability of the persistent configurations. The method was developed earlier in the context of the two-dimensional lattice and applied to the onsite and offsite configurations (called the vortex cross and the vortex cell) by using semianalytical computations [D.E. Pelinovsky, P.G. Kevrekidis, D. Frantzeskakis, Physica D 212 (2005) 20-53; P.G. Kevrekidis, D.E. Pelinovsky, Proc. R. Soc. A 462 (2006) 2671-2694]. The present treatment develops a full symbolic computational package which takes a desired waveform at the anticontinuum limit of uncoupled sites, performs a required number of Lyapunov-Schmidt reductions and outputs the predictions on whether the configuration persists, for finite coupling, in the three-dimensional lattice and whether it is stable or unstable. It also provides approximations for the eigenvalues of the linearized stability problem. We report a number of applications of the algorithm to important multisite three-dimensional configurations, such as the simple cube, the double cross and the diamond. For each configuration, we identify exactly one solution, which is stable for small coupling between lattice nodes.

  11. Patient-specific three-dimensional composite bone models for teaching and operation planning.

    Science.gov (United States)

    Matthews, Felix; Messmer, Peter; Raikov, Vladislav; Wanner, Guido A; Jacob, Augustinus L; Regazzoni, Pietro; Egli, Adrian

    2009-10-01

    Orthopedic trauma care relies on two-dimensional radiograms both before and during the operation. Understanding the three-dimensional nature of complex fractures on plain radiograms is challenging. Modern fluoroscopes can acquire three-dimensional volume datasets even during an operation, but the device limitations constrain the acquired volume to a cube of only 12-cm edge. However, viewing the surrounding intact structures is important to comprehend the fracture in its context. We suggest merging a fluoroscope's volume scan into a generic bone model to form a composite full-length 3D bone model. Materials consisted of one cadaver bone and 20 three-dimensional surface models of human femora. Radiograms and computed tomography scans were taken before and after applying a controlled fracture to the bone. A 3D scan of the fracture was acquired using a mobile fluoroscope (Siemens Siremobil). The fracture was fitted into the generic bone models by rigid registration using a modified least-squares algorithm. Registration precision was determined and a clinical appraisal of the composite models obtained. Twenty composite bone models were generated. Average registration precision was 2.0 mm (range 1.6 to 2.6). Average processing time on a laptop computer was 35 s (range 20 to 55). Comparing synthesized radiograms with the actual radiograms of the fractured bone yielded clinically satisfactory results. A three-dimensional full-length representation of a fractured bone can reliably be synthesized from a short scan of the patient's fracture and a generic bone model. This patient-specific model can subsequently be used for teaching, surgical operation planning, and intraoperative visualization purposes.

  12. A finite area scheme for shallow granular flows on three-dimensional surfaces

    Science.gov (United States)

    Rauter, Matthias

    2017-04-01

    Shallow granular flow models have become a popular tool for the estimation of natural hazards, such as landslides, debris flows and avalanches. The shallowness of the flow allows to reduce the three-dimensional governing equations to a quasi two-dimensional system. Three-dimensional flow fields are replaced by their depth-integrated two-dimensional counterparts, which yields a robust and fast method [1]. A solution for a simple shallow granular flow model, based on the so-called finite area method [3] is presented. The finite area method is an adaption of the finite volume method [4] to two-dimensional curved surfaces in three-dimensional space. This method handles the three dimensional basal topography in a simple way, making the model suitable for arbitrary (but mildly curved) topography, such as natural terrain. Furthermore, the implementation into the open source software OpenFOAM [4] is shown. OpenFOAM is a popular computational fluid dynamics application, designed so that the top-level code mimics the mathematical governing equations. This makes the code easy to read and extendable to more sophisticated models. Finally, some hints on how to get started with the code and how to extend the basic model will be given. I gratefully acknowledge the financial support by the OEAW project "beyond dense flow avalanches". Savage, S. B. & Hutter, K. 1989 The motion of a finite mass of granular material down a rough incline. Journal of Fluid Mechanics 199, 177-215. Ferziger, J. & Peric, M. 2002 Computational methods for fluid dynamics, 3rd edn. Springer. Tukovic, Z. & Jasak, H. 2012 A moving mesh finite volume interface tracking method for surface tension dominated interfacial fluid flow. Computers & fluids 55, 70-84. Weller, H. G., Tabor, G., Jasak, H. & Fureby, C. 1998 A tensorial approach to computational continuum mechanics using object-oriented techniques. Computers in physics 12(6), 620-631.

  13. Photogrammetry: applications of a three-dimensional remote measurement technique

    International Nuclear Information System (INIS)

    Peak, K.

    1988-01-01

    Photogrammetry is defined as the precise art of abstracting measurements from photographic images. Used for many years as a means to produce the world's maps, it has, in recent years, been applied in many engineering environments. The nuclear industry has, in particular, benefitted from the close range applications of photogrammetry. This paper sets out to describe the techniques involved, from the site photography through to the analytical data extraction. It will include a number of examples of where photogrammetry has been used in the nuclear industry as a remote measurement technique, from simple monitoring exercises to the compilation of complex three-dimensional as-built computer models. (author)

  14. Observation of three dimensional optical rogue waves through obstacles

    Energy Technology Data Exchange (ETDEWEB)

    Leonetti, Marco, E-mail: marco.leonetti@roma1.infn.it [Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Viale Regina Elena, 291 00161 Roma (RM) (Italy); Conti, Claudio [ISC-CNR and Department of Physics, University Sapienza, P.le Aldo Moro 5, I-00185 Roma (Italy)

    2015-06-22

    We observe three-dimensional rogue waves in the speckle distribution of a spatially modulated optical beam. Light is transmitted beyond a partially reflecting obstacle generating optical rogue waves at a controlled position in the shadow of the barrier. When the barrier transmits only 0.07% of the input laser power, we observe the mostly localized event. These results demonstrate that an optimum amount of spatial non-homogeneity maximizes the probability of a gigantic event while the technique we exploit enables to control light behind a fully reflective wall.

  15. Surgical accuracy of three-dimensional virtual planning

    DEFF Research Database (Denmark)

    Stokbro, Kasper; Aagaard, Esben; Torkov, Peter

    2016-01-01

    This retrospective study evaluated the precision and positional accuracy of different orthognathic procedures following virtual surgical planning in 30 patients. To date, no studies of three-dimensional virtual surgical planning have evaluated the influence of segmentation on positional accuracy...... and transverse expansion. Furthermore, only a few have evaluated the precision and accuracy of genioplasty in placement of the chin segment. The virtual surgical plan was compared with the postsurgical outcome by using three linear and three rotational measurements. The influence of maxillary segmentation...

  16. Quantum tunneling from three-dimensional black holes

    International Nuclear Information System (INIS)

    Ejaz, Asiya; Gohar, H.; Lin, Hai; Saifullah, K.; Yau, Shing-Tung

    2013-01-01

    We study Hawking radiation from three-dimensional black holes. For this purpose the emission of charged scalar and charged fermionic particles is investigated from charged BTZ black holes, with and without rotation. We use the quantum tunneling approach incorporating WKB approximation and spacetime symmetries. Another class of black holes which is asymptotic to a Sol three-manifold has also been investigated. This procedure gives us the tunneling probability of outgoing particles, and we compute the temperature of the radiation for these black holes. We also consider the quantum tunneling of particles from black hole asymptotic to Sol geometry

  17. Modified Three-Dimensional Multicarrier Optical Prime Codes

    Directory of Open Access Journals (Sweden)

    Rajesh Yadav

    2016-01-01

    Full Text Available We propose a mathematical model for novel three-dimensional multicarrier optical codes in terms of wavelength/time/space based on the prime sequence algorithm. The proposed model has been extensively simulated on MATLAB for prime numbers (P to analyze the performance of code in terms of autocorrelation and cross-correlation. The simulated outcome resembles the mathematical model and gives better results over other methods available in the literature as far as autocorrelation and cross-correlation are concerned. The proposed 3D optical codes are more efficient in terms of cardinality, improved security, and providing quality of services.

  18. Three-dimensional display techniques: description and critique of methods

    International Nuclear Information System (INIS)

    Budinger, T.F.

    1982-01-01

    The recent advances in non invasive medical imaging of 3 dimensional spatial distribution of radionuclides, X-ray attenuation coefficients, and nuclear magnetic resonance parameters necessitate development of a general method for displaying these data. The objective of this paper is to give a systematic description and comparison of known methods for displaying three dimensional data. The discussion of display methods is divided into two major categories: 1) computer-graphics methods which use a two dimensional display screen; and 2) optical methods (such as holography, stereopsis and vari-focal systems)

  19. Impurity states in two and three dimensional disordered system S

    International Nuclear Information System (INIS)

    Silva, A.F. da; Fabbri, M.

    1984-01-01

    We investigate the microscopic structure of the impurity states in two-and three-dimensional (2D and 3D) disordered system. A cluster model is outlined for the donor impurity density of states (DIDS) of doped semiconductors. It is shown that the impurity states are very sensitive to a change in the dimensionality of the system, i.e., from 3D to 2D system. It is found that all eigenstates become localized in 2D disordered system for a large range of concentration. (author) [pt

  20. Evaluation of solar energy over three dimensional objects

    International Nuclear Information System (INIS)

    Serposhan, S.; Yaghoubi, M.

    2002-01-01

    The knowledge of solar irradiation is important in heating and cooling of buildings architectural engineering, various solar energy utilizations, and for any system design exposed to sun radiation. In the present article, simulation is made to predict solar irradiation over any three-dimensional objects. Special consideration is made to evaluate solar radiation intensity distribution over semi-circular roof and domed roofs. For practical applications, hourly and average daily solar radiation distribution for a series of three Heller type huge cooling towers of Fars Power Plant is also determined

  1. Three-dimensional analysis of two-pile caps

    Directory of Open Access Journals (Sweden)

    T.E.T. Buttignol

    Full Text Available This paper compares the results between a non-linear three-dimensional numerical analysis of pile caps with two piles and the experimental study conducted by Delalibera. It is verified the load-carrying capacity, the crack pattern distribution, the principal stress in concrete and steel, the deflection and the fracture of the pile cap. The numerical analysis is executed with the finite-element software ATENA 3D, considering a perfect bond between concrete and steel. The numerical and experimental results are presented and have demonstrated a good approximation, reasserting the results of the experimental model and corroborating the theory.

  2. Three-dimensional fractional topological insulators in coupled Rashba layers

    Science.gov (United States)

    Volpez, Yanick; Loss, Daniel; Klinovaja, Jelena

    2017-08-01

    We propose a model of three-dimensional topological insulators consisting of weakly coupled electron- and hole-gas layers with Rashba spin-orbit interaction stacked along a given axis. We show that in the presence of strong electron-electron interactions the system realizes a fractional strong topological insulator, where the rotational symmetry and condensation energy arguments still allow us to treat the problem as quasi-one-dimensional with bosonization techniques. We also show that if Rashba and Dresselhaus spin-orbit interaction terms are equally strong, by doping the system with magnetic impurities, one can bring it into the Weyl semimetal phase.

  3. Single-camera, three-dimensional particle tracking velocimetry

    OpenAIRE

    Peterson, K.; Regaard, B.; Heinemann, S.; Sick, V.

    2012-01-01

    This paper introduces single-camera, three-dimensional particle tracking velocimetry (SC3D-PTV), an image-based, single-camera technique for measuring 3-component, volumetric velocity fields in environments with limited optical access, in particular, optically accessible internal combustion engines. The optical components used for SC3D-PTV are similar to those used for two-camera stereoscopic-PIV, but are adapted to project two simultaneous images onto a single image sensor. A novel PTV algor...

  4. Tag gas burnup based on three-dimensional FTR analysis

    International Nuclear Information System (INIS)

    Kidman, R.B.

    1976-01-01

    Flux spectra from a three-dimensional diffusion theory analysis of the Fast Test Reactor (FTR) are used to predict gas tag ratio changes, as a function of exposure, for each FTR fuel and absorber subassembly plenum. These flux spectra are also used to predict Xe-125 equilibrium activities in absorber plena in order to assess the feasibility of using Xe-125 gamma rays to detect and distinguish control rod failures from fuel rod failures. Worst case tag burnup changes are used in conjunction with burnup and mass spectrometer uncertainties to establish the minimum spacing of tags which allows the tags to be unambiguously identified

  5. Photonic Paint Developed with Metallic Three-Dimensional Photonic Crystals

    Science.gov (United States)

    Sun, Po; Williams, John D.

    2012-01-01

    This work details the design and simulation of an inconspicuous photonic paint that can be applied onto an object for anticounterfeit and tag, track, and locate (TTL) applications. The paint consists of three-dimensional metallic tilted woodpile photonic crystals embedded into a visible and infrared transparent polymer film, which can be applied to almost any surface. The tilted woodpile photonic crystals are designed with a specific pass band detectable at nearly all incident angles of light. When painted onto a surface, these crystals provide a unique reflective infra-red optical signature that can be easily observed and recorded to verify the location or contents of a package.

  6. CATIA Core Tools Computer Aided Three-Dimensional Interactive Application

    CERN Document Server

    Michaud, Michel

    2012-01-01

    CATIA Core Tools: Computer-Aided Three-Dimensional Interactive Application explains how to use the essential features of this cutting-edge solution for product design and innovation. The book begins with the basics, such as launching the software, configuring the settings, and managing files. Next, you'll learn about sketching, modeling, drafting, and visualization tools and techniques. Easy-to-follow instructions along with detailed illustrations and screenshots help you get started using several CATIA workbenches right away. Reverse engineering--a valuable product development skill--is also covered in this practical resource.

  7. Fracture of three-dimensional fuse networks with quenched disorder

    OpenAIRE

    Räisänen, V. I.; Alava, M. J.; Nieminen, Risto M.

    1998-01-01

    We study a fracture on a quasistatic time scale in a three-dimensional (3D) fuse network model with “strong” and “weak” disorder. These two cases differ noticeably in the development of the fracture. For strong disorder the damage scaling is very close to volumelike [number of broken bonds Nb∼L3/(lnL)0.3] unlike for weak disorder [Nb∼L2.4/(lnL)0.3]. With strong disorder global load sharing is only approximately valid. The size distribution of “avalanches” of broken fuses in the failure follow...

  8. Three-dimensional characterization of stress corrosion cracks

    DEFF Research Database (Denmark)

    Lozano-Perez, S.; Rodrigo, P.; Gontard, Lionel Cervera

    2011-01-01

    the best spatial resolution. To illustrate the power of these techniques, different parts of dominant stress corrosion cracks in Ni-alloys and stainless steels have been reconstructed in 3D. All relevant microstructural features can now be studied in detail and its relative orientation respect......Understanding crack propagation and initiation is fundamental if stress corrosion cracking (SCC) mechanisms are to be understood. However, cracking is a three-dimensional (3D) phenomenon and most characterization techniques are restricted to two-dimensional (2D) observations. In order to overcome...

  9. Three-dimensional laser pulse intensity diagnostic for photoinjectors

    Directory of Open Access Journals (Sweden)

    Heng Li

    2011-11-01

    Full Text Available Minimizing the electron-beam emittance of photoinjectors is an important task for maximizing the brightness of the next-generation x-ray facilities, such as free-electron lasers and energy recovery linacs. Optimally shaped laser pulses can significantly reduce emittance. A reliable diagnostic for the laser pulse intensity is required for this purpose. We demonstrate measurement of three-dimensional spatiotemporal intensity profiles, with spatial resolution of 20  μm and temporal resolution of 130 fs. The capability is illustrated by measurements of stacked soliton pulses and pulses from a dissipative-soliton laser.

  10. Teaching veterinary obstetrics using three-dimensional animation technology.

    Science.gov (United States)

    Scherzer, Jakob; Buchanan, M Flint; Moore, James N; White, Susan L

    2010-01-01

    In this three-year study, test scores for students taught veterinary obstetrics in a classroom setting with either traditional media (photographs, text, and two-dimensional graphical presentations) were compared with those for students taught by incorporating three-dimensional (3D) media (linear animations and interactive QuickTime Virtual Reality models) into the classroom lectures. Incorporation of the 3D animations and interactive models significantly increased students' scores on essay questions designed to assess their comprehension of the subject matter. This approach to education may help to better prepare students for dealing with obstetrical cases during their final clinical year and after graduation.

  11. Coherent states on horospheric three-dimensional Lobachevsky space

    Energy Technology Data Exchange (ETDEWEB)

    Kurochkin, Yu., E-mail: y.kurochkin@ifanbel.bas-net.by; Shoukavy, Dz., E-mail: shoukavy@ifanbel.bas-net.by [Institute of Physics, National Academy of Sciences of Belarus, 68 Nezalezhnasci Ave., Minsk 220072 (Belarus); Rybak, I., E-mail: Ivan.Rybak@astro.up.pt [Institute of Physics, National Academy of Sciences of Belarus, 68 Nezalezhnasci Ave., Minsk 220072 (Belarus); Instituto de Astrofísica e Ciências do Espaço, CAUP, Rua das Estrelas, 4150-762 Porto (Portugal); Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2016-08-15

    In the paper it is shown that due to separation of variables in the Laplace-Beltrami operator (Hamiltonian of a free quantum particle) in horospheric and quasi-Cartesian coordinates of three dimensional Lobachevsky space, it is possible to introduce standard (“conventional” according to Perelomov [Generalized Coherent States and Their Applications (Springer-Verlag, 1986), p. 320]) coherent states. Some problems (oscillator on horosphere, charged particle in analogy of constant uniform magnetic field) where coherent states are suitable for treating were considered.

  12. Three-Dimensional Magnetohydrodynamic Simulation of Slapper Initiation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, J S; Hrousis, C A

    2010-03-09

    Although useful information can be gleaned from 2D and even 1D simulations of slapper type initiation systems, these systems are inherently three-dimensional and therefore require full 3D representation to model all relevant details. Further, such representation provides additional insight into optimizing the design of such devices from a first-principles perspective and can thereby reduce experimental costs. We discuss in this paper several ongoing efforts in modeling these systems, our pursuit of validation, and extension of these methods to other systems. Our results show the substantial dependence upon highly accurate global equations of state and resistivity models in these analyses.

  13. Field approach to three-dimensional gene expression pattern characterization

    Science.gov (United States)

    Costa, L. da F.; Travençolo, B. A. N.; Azeredo, A.; Beletti, M. E.; Müller, G. B.; Rasskin-Gutman, D.; Sternik, G.; Ibañes, M.; Izpisúa-Belmonte, J. C.

    2005-04-01

    We present a vector field method for obtaining the spatial organization of three-dimensional patterns of gene expression based on gradients and lines of force obtained by numerical integration. The convergence of these lines of force in local maxima are centers of gene expression, providing a natural and powerful framework to characterize the organization and dynamics of biological structures. We apply this methodology to analyze the expression pattern of the enhanced green fluorescent protein (EGFP) driven by the promoter of light chain myosin II during zebrafish heart formation.

  14. Self-assembled three-dimensional chiral colloidal architecture

    Science.gov (United States)

    Ben Zion, Matan Yah; He, Xiaojin; Maass, Corinna C.; Sha, Ruojie; Seeman, Nadrian C.; Chaikin, Paul M.

    2017-11-01

    Although stereochemistry has been a central focus of the molecular sciences since Pasteur, its province has previously been restricted to the nanometric scale. We have programmed the self-assembly of micron-sized colloidal clusters with structural information stemming from a nanometric arrangement. This was done by combining DNA nanotechnology with colloidal science. Using the functional flexibility of DNA origami in conjunction with the structural rigidity of colloidal particles, we demonstrate the parallel self-assembly of three-dimensional microconstructs, evincing highly specific geometry that includes control over position, dihedral angles, and cluster chirality.

  15. Wave field restoration using three-dimensional Fourier filtering method.

    Science.gov (United States)

    Kawasaki, T; Takai, Y; Ikuta, T; Shimizu, R

    2001-11-01

    A wave field restoration method in transmission electron microscopy (TEM) was mathematically derived based on a three-dimensional (3D) image formation theory. Wave field restoration using this method together with spherical aberration correction was experimentally confirmed in through-focus images of amorphous tungsten thin film, and the resolution of the reconstructed phase image was successfully improved from the Scherzer resolution limit to the information limit. In an application of this method to a crystalline sample, the surface structure of Au(110) was observed in a profile-imaging mode. The processed phase image showed quantitatively the atomic relaxation of the topmost layer.

  16. Conoscopic holography: toward three-dimensional reconstructions of opaque objects.

    Science.gov (United States)

    Mugnier, L M

    1995-03-10

    Conoscopic holography is an interferometric technique that permits the recording of three-dimensional objects. A two-step scheme is presented to recover an opaque object's shape from its conoscopic hologram, consisting of a reconstruction algorithm to give a first estimate of the shape and an iterative restoration procedure that uses the object's support information to make the reconstruction more robust. The existence, uniqueness, and stability of the solution, as well as the convergence of the restoration algorithm, are studied. A preliminary experimental result is presented.

  17. Three Dimensional Digital Image Processing using Edge Detectors

    Directory of Open Access Journals (Sweden)

    John Schmeelk

    2005-11-01

    Full Text Available This paper provides an introduction to three dimensional image edge detection and its relationship to partial derivatives, convolutions and wavelets. We are especially addressing the notion of edge detection because it has far reaching applications in all areas of research to include medical research. A patient can be diagnosed as having an aneurysm by studying an angiogram. An angiogram is the visual view of the blood vessels whereby the edges are highlighted through the implementation of edge detectors. This process is completed through convolution, wavelets and matrix techniques. Some illustrations included will be vertical, horizontal, Sobel and wavelet edge detectors.

  18. Three-dimensional imaging techniques: A literature review

    Science.gov (United States)

    Karatas, Orhan Hakki; Toy, Ebubekir

    2014-01-01

    Imaging is one of the most important tools for orthodontists to evaluate and record size and form of craniofacial structures. Orthodontists routinely use 2-dimensional (2D) static imaging techniques, but deepness of structures cannot be obtained and localized with 2D imaging. Three-dimensional (3D) imaging has been developed in the early of 1990's and has gained a precious place in dentistry, especially in orthodontics. The aims of this literature review are to summarize the current state of the 3D imaging techniques and to evaluate the applications in orthodontics. PMID:24966761

  19. Three-dimensional temporal reconstruction and analysis of plume images

    Science.gov (United States)

    Dhawan, Atam P.; Disimile, Peter J.; Peck, Charles, III

    1992-01-01

    An experiment with two subsonic jets generating a cross-flow was conducted as part of a study of the structural features of temporal reconstruction of plume images. The flow field structure was made visible using a direct injection flow visualization technique. It is shown that image analysis and temporal three-dimensional visualization can provide new information on the vortical structural dynamics of multiple jets in a cross-flow. It is expected that future developments in image analysis, quantification and interpretation, and flow visualization of rocket engine plume images may provide a tool for correlating the engine diagnostic features by interpreting the evolution of the structures in the plume.

  20. The Electron in Three-Dimensional Momentum Space

    Science.gov (United States)

    Mantovani, L.; Bacchetta, A.; Pasquini, B.

    2016-07-01

    We study the electron as a system composed of an electron and a photon and derive the leading-twist transverse-momentum-dependent distribution functions for both the electron and photon in the dressed electron, thereby offering a three-dimensional description of the dressed electron in momentum space. To obtain the distribution functions, we apply both the formalism of light-front wave function overlap representation and the diagrammatic approach; we discuss the comparison of our results between light-cone gauge and Feynman gauge, discussing the role of the Wilson lines to obtain gauge-independent results. We provide examples of plots of the computed distributions.

  1. Turbulence in Three Dimensional Simulations of Magnetopause Reconnection

    Science.gov (United States)

    Drake, J. F.; Price, L.; Swisdak, M.; Burch, J. L.; Cassak, P.; Dahlin, J. T.; Ergun, R.

    2017-12-01

    We present two- and three-dimensional particle-in-cell simulations of the 16 October 2015 MMS magnetopause reconnection event. While the two-dimensional simulation is laminar, turbulence develops at both the x-line and along the magnetic separatrices in the three-dimensional simulation. This turbulence is electromagnetic in nature, is characterized by a wavevector k given by kρ e ˜(m_e/m_i)0.25 with ρ e the electron Larmor radius, and appears to have the ion pressure gradient as its source of free energy. Taken together, these results suggest the instability is a variant of the lower-hybrid drift instability. The turbulence produces electric field fluctuations in the out-of-plane direction (the direction of the reconnection electric field) with an amplitude of around ± 10 mV/m, which is much greater than the reconnection electric field of around 0.1 mV/m. Such large values of the out-of-plane electric field have been identified in the MMS data. The turbulence in the simulation controls the scale lengths of the density profile and current layers in asymmetric reconnection, driving them closer to √ {ρ eρ_i } than the ρ e or de scalings seen in 2D reconnection simulations, where de is the electron inertial length. The turbulence is strong enough to make the magnetic field around the reconnection island chaotic and produces both anomalous resistivity and anomalous viscosity. Each contribute significantly to breaking the frozen-in condition in the electron diffusion region. The crescent-shaped features in velocity space seen both in MMS observations and in two-dimensional simulations survive, even in the turbulent environment of the three-dimensional system. We compare and contrast these results to a three-dimensional simulation of the 8 December 2015 MMS magnetopause reconnection event in which the reconnecting and out-of-plane guide fields are comparable. LHDI is still present in this event, although its appearance is modified by the presence of the guide

  2. Three-Dimensional Bone Adaptation of the Proximal Femur

    DEFF Research Database (Denmark)

    Bagge, Mette

    1998-01-01

    The bone remodeling of a three-dimensional model of the proximal femur is considered. The bone adaptation is numerically described as an evolution in time formulated such that the structural change goes in an optimal direction within each time step for the optimal boundary conditions. In the bone...... remodeling scheme is included the memory of past loadings to account for the delay in the bone response to the load changes. In order to get a realistic bone adaptation process, the bone structure at the onset of the remodeling needs to be realistic too. A start design is obtained by structural optimization...

  3. Plenoptic Imaging of a Three Dimensional Cold Atom Cloud

    Science.gov (United States)

    Lott, Gordon

    2017-04-01

    A plenoptic imaging system is capable of sampling the rays of light in a volume, both spatially and angularly, providing information about the three dimensional (3D) volume being imaged. The extraction of the 3D structure of a cold atom cloud is demonstrated, using a single plenoptic camera and a single image. The reconstruction is tested against a reference image and the results discussed along with the capabilities and limitations of the imaging system. This capability is useful when the 3D distribution of the atoms is desired, such as determining the shape of an atom trap, particularly when there is limited optical access. Gratefully acknowledge support from AFRL.

  4. Three-dimensional, subsurface imaging synthetic aperture radar

    International Nuclear Information System (INIS)

    Moussally, G.J.

    1994-01-01

    The objective of this applied research and devolpment project is to develop a system known as 3-D SISAR. This sytem consists of a gound penetrating radar with software algorithms designed for detection, location, and identification of buried objects in the underground hazardous waste environments found at US DOE storage sites. Three-dimensional maps can assist the development of remdiation strategies and characterization of the digface during remediation. The system should also be useful for monitoring hydrocarbon-based contaminant migration after remediation. 5 figs

  5. Digital Simulation of Thunder from Three-Dimensional Lightning

    Science.gov (United States)

    Dunkin, James; Fleisch, Daniel

    2010-04-01

    The physics of lightning and its resultant thunder have been investigated by many people, but we still don't have a full understanding of the governing processes. In this study, we have constructed a three-dimensional model of lightning using MATLAB^ software, and used N-waves as postulated by Ribner and Roy to synthesize the resultant thunder signature. In addition, we have taken an FFT of the thunder signature, and compared the time-domain waveform and frequency spectrum to recordings of thunder taken over the summer of 2009. This analysis is done with the goal of further understanding the processes of thunder production.

  6. Three dimensional magnetic solutions in massive gravity with (nonlinear field

    Directory of Open Access Journals (Sweden)

    S.H. Hendi

    2017-12-01

    Full Text Available The Noble Prize in physics 2016 motivates one to study different aspects of topological properties and topological defects as their related objects. Considering the significant role of the topological defects (especially magnetic strings in cosmology, here, we will investigate three dimensional horizonless magnetic solutions in the presence of two generalizations: massive gravity and nonlinear electromagnetic field. The effects of these two generalizations on properties of the solutions and their geometrical structure are investigated. The differences between de Sitter and anti de Sitter solutions are highlighted and conditions regarding the existence of phase transition in geometrical structure of the solutions are studied.

  7. Life is three-dimensional, and it begins with molecules.

    Directory of Open Access Journals (Sweden)

    Philip E Bourne

    2017-03-01

    Full Text Available The iconic image of the DNA double helix embodies the central role that three-dimensional structures play in understanding biological processes, which, in turn, impact health and well-being. Here, that role is explored through the eyes of one scientist, who has been lucky enough to have over 150 talented people pass through his laboratory. Each contributed to that understanding. What follows is a small fraction of their story, with an emphasis on basic research outcomes of importance to society at large.

  8. Three-dimensional illumination procedure for photodynamic therapy of dermatology

    Science.gov (United States)

    Hu, Xiao-ming; Zhang, Feng-juan; Dong, Fei; Zhou, Ya

    2014-09-01

    Light dosimetry is an important parameter that affects the efficacy of photodynamic therapy (PDT). However, the irregular morphologies of lesions complicate lesion segmentation and light irradiance adjustment. Therefore, this study developed an illumination demo system comprising a camera, a digital projector, and a computing unit to solve these problems. A three-dimensional model of a lesion was reconstructed using the developed system. Hierarchical segmentation was achieved with the superpixel algorithm. The expected light dosimetry on the targeted lesion was achieved with the proposed illumination procedure. Accurate control and optimization of light delivery can improve the efficacy of PDT.

  9. The three-dimensional crystal structure of cholera toxin

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Rong-Guang; Westbrook, M.L.; Nance, S.; Spangler, B.D. [Argonne National Lab., IL (United States); Scott, D.L. [Yale Univ., New Haven, CT (United States). Dept. of Molecular Biophysics and Biochemistry; Westbrook, E.M. [Northwestern Univ., Evanston, IL (United States)

    1996-02-01

    The clinical manifestations of cholera are largely attributable to the actions of a secreted hexameric AB{sub 5} enterotoxin (choleragen). We have solved the three-dimensional structure of choleragen at 2.5 {Angstrom} resolution and compared the refined coordinates with those of choleragenoid (isolated B pentamer) and the heat-labile enterotoxin from Escherichia coli (LT). The crystalline coordinates provide a detailed view of the stereochemistry implicated in binding to GM1 gangliosides and in carrying out ADP-ribosylation. The A2 chain of choleragen, in contrast to that of LT, is a nearly continuous {alpha}-helix with an interpretable carboxyl tail.

  10. A Three-dimensional Topological Model of Ternary Phase Diagram

    International Nuclear Information System (INIS)

    Mu, Yingxue; Bao, Hong

    2017-01-01

    In order to obtain a visualization of the complex internal structure of ternary phase diagram, the paper realized a three-dimensional topology model of ternary phase diagram with the designed data structure and improved algorithm, under the guidance of relevant theories of computer graphics. The purpose of the model is mainly to analyze the relationship between each phase region of a ternary phase diagram. The model not only obtain isothermal section graph at any temperature, but also extract a particular phase region in which users are interested. (paper)

  11. Strongly interacting atom lasers in three-dimensional optical lattices.

    Science.gov (United States)

    Hen, Itay; Rigol, Marcos

    2010-10-29

    We show that the dynamical melting of a Mott insulator in a three-dimensional lattice leads to condensation at nonzero momenta, a phenomenon that can be used to generate strongly interacting atom lasers in optical lattices. For infinite on-site repulsion, the case considered here, the momenta at which bosons condense are determined analytically and found to have a simple dependence on the hopping amplitudes. The occupation of the condensates is shown to scale linearly with the total number of atoms in the initial Mott insulator. Our results are obtained by using a Gutzwiller-type mean-field approach, gauged against exact-diagonalization solutions of small systems.

  12. On a Three Dimensional Vision Based Collision Avoidance Model

    Science.gov (United States)

    Parzani, Céline; Filbet, Francis

    2017-08-01

    This paper presents a three dimensional collision avoidance approach for aerial vehicles inspired by coordinated behaviors in biological groups. The proposed strategy aims to enable a group of vehicles to converge to a common destination point avoiding collisions with each other and with moving obstacles in their environment. The interaction rules lead the agents to adapt their velocity vectors through a modification of the relative bearing angle and the relative elevation. Moreover the model satisfies the limited field of view constraints resulting from individual perception sensitivity. From the proposed individual based model, a mean-field kinetic model is derived. Simulations are performed to show the effectiveness of the proposed model.

  13. Analysis and visualization of complex unsteady three-dimensional flows

    Science.gov (United States)

    Van Dalsem, William R.; Buning, Pieter G.; Dougherty, F. Carroll; Smith, Merritt H.

    1989-01-01

    Flow field animation is the natural choice as a tool in the analysis of the numerical simulations of complex unsteady three-dimensional flows. The PLOT4D extension of the widely used PLOT3D code to allow the interactive animation of a broad range of flow variables was developed and is presented. To allow direct comparison with unsteady experimental smoke and dye flow visualization, the code STREAKER was developed to produce time accurate streaklines. Considerations regarding the development of PLOT4D and STREAKER, and example results are presented.

  14. Three-dimensional nonlinear waves under spatial confinement

    OpenAIRE

    Azhand, Arash

    2016-01-01

    The aim of my thesis is to study the evolution of scroll waves under spatial confinement both experimentally as well as numerically. Scroll waves represent three-dimensional (3D) analogs of spiral waves. In the simplest case, the central axis around which a scroll wave rotates is a straight line. The line is named the filament of the scroll wave, and each infinitesimal cross-section represents the core of a spiral wave. Two specific types of scroll waves are considered: (1) Straight scroll wa...

  15. Three-dimensional integrated CAE system applying computer graphic technique

    International Nuclear Information System (INIS)

    Kato, Toshisada; Tanaka, Kazuo; Akitomo, Norio; Obata, Tokayasu.

    1991-01-01

    A three-dimensional CAE system for nuclear power plant design is presented. This system utilizes high-speed computer graphic techniques for the plant design review, and an integrated engineering database for handling the large amount of nuclear power plant engineering data in a unified data format. Applying this system makes it possible to construct a nuclear power plant using only computer data from the basic design phase to the manufacturing phase, and it increases the productivity and reliability of the nuclear power plants. (author)

  16. Three-dimensional structure of the γ-secretase complex

    International Nuclear Information System (INIS)

    Ogura, Toshihiko; Mio, Kazuhiro; Hayashi, Ikuo; Miyashita, Hiroyuki; Fukuda, Rie; Kopan, Raphael; Kodama, Tatsuhiko; Hamakubo, Takao; Iwastubo, Takeshi; Tomita, Taisuke; Sato, Chikara

    2006-01-01

    γ-Secretase belongs to an atypical class of aspartic proteases that hydrolyzes peptide bonds within the transmembrane domain of substrates, including amyloid-β precursor protein and Notch. γ-Secretase is comprised of presenilin, nicastrin, APH-1, and PEN-2 which form a large multimeric membrane protein complex, the three-dimensional structure of which is unknown. To gain insight into the structure of this complex enzyme, we purified functional γ-secretase complex reconstituted in Sf9 cells and analyzed it using negative stain electron microscopy and 3D reconstruction techniques. Analysis of 2341 negatively stained particle images resulted in the three-dimensional representation of γ-secretase at a resolution of 48 A. The structure occupies a volume of 560 x 320 x 240 A and resembles a flat heart comprised of two oppositely faced, dimpled domains. A low density space containing multiple pores resides between the domains. Some of the dimples in the putative transmembrane region may house the catalytic site. The large dimensions are consistent with the observation that γ-secretase activity resides within a high molecular weight complex

  17. Three-dimensional flows in a transonic compressor rotor

    Science.gov (United States)

    Reid, Lonnie; Celestina, Mark L.; Dewitt, Kenneth; Keith, Theo

    1991-01-01

    This study involves an experimental and numerical investigation of the three-dimensional flows in a transonic compressor rotor. A variety of data which could be used, in a complementary fashion, to validate/calibrate the computational fluid dynamics turbomachinery code and improve understanding of the flow physics, were acquired. Detailed radial survey data which consisted of total pressure, total temperature, static pressure and flow angle were obtained at stations upstream and downstream of the rotor blade. Detailed velocity and turbulence profiles were obtained upstream of the rotor and used as the upstream boundary conditions for the numerical analysis. Calibrated flush-mounted hot film probes were used to measure wall shear stress on the hub and casing walls upstream of the rotor. The blade-to-blade shear-stress angle distributions were obtained at two axial locations on the rotor casing, using flush-mounted hot film probes. A numerical analysis conducted using a three-dimensional Navier-Stokes code was compared with the experimental results.

  18. Three-dimensional volumetric display by inclined-plane scanning

    Science.gov (United States)

    Miyazaki, Daisuke; Eto, Takuma; Nishimura, Yasuhiro; Matsushita, Kenji

    2003-05-01

    A volumetric display system based on three-dimensional (3-D) scanning that uses an inclined two-dimensional (2-D) image is described. In the volumetric display system a 2-D display unit is placed obliquely in an imaging system into which a rotating mirror is inserted. When the mirror is rotated, the inclined 2-D image is moved laterally. A locus of the moving image can be observed by persistence of vision as a result of the high-speed rotation of the mirror. Inclined cross-sectional images of an object are displayed on the display unit in accordance with the position of the image plane to observe a 3-D image of the object by persistence of vision. Three-dimensional images formed by this display system satisfy all the criteria for stereoscopic vision. We constructed the volumetric display systems using a galvanometer mirror and a vector-scan display unit. In addition, we constructed a real-time 3-D measurement system based on a light section method. Measured 3-D images can be reconstructed in the 3-D display system in real time.

  19. Three-dimensional MRI with independent slab excitation and encoding.

    Science.gov (United States)

    Eissa, Amir; Wilman, Alan H

    2012-02-01

    Three-dimensional MRI is typically performed with the same orientation for radiofrequency slab excitation and slab select phase encoding. We introduce independent slab excitation and encoding to create a new degree of freedom in three-dimensional MRI, which is the angular relationship between the prescribed excitation volume and the voxel encoding grid. By separating the directions of slab excitation and slab phase encoding, the independent slab excitation and encoding method allows choice of optimal voxel orientation, while maintaining volume excitation based on anatomic landmarks. The method requires simple pulse sequence modifications and uses standard image reconstruction followed by removal of aliasing and image reformatting. The independent slab excitation and encoding method enables arbitrary oblique angle imaging using fixed voxel encoding gradients to maintain similar eddy current, concomitant field, or magnetic dipole effects independent of the oblique angle of excitation. We apply independent slab excitation and encoding to phase and susceptibility-weighted imaging using fixed voxel encoding aligned with the main magnetic field to demonstrate its value in both standardizing and improving image contrast, when using arbitrary oblique imaging volumes. Copyright © 2011 Wiley Periodicals, Inc.

  20. CFD three dimensional wake analysis in complex terrain

    Science.gov (United States)

    Castellani, F.; Astolfi, D.; Terzi, L.

    2017-11-01

    Even if wind energy technology is nowadays fully developed, the use of wind energy in very complex terrain is still challenging. In particular, it is challenging to characterize the combination effects of wind ow over complex terrain and wake interactions between nearby turbines and this has a practical relevance too, for the perspective of mitigating anomalous vibrations and loads as well improving the farm efficiency. In this work, a very complex terrain site has been analyzed through a Reynolds-averaged CFD (Computational Fluid Dynamics) numerical wind field model; in the simulation the inuence of wakes has been included through the Actuator Disk (AD) approach. In particular, the upstream turbine of a cluster of 4 wind turbines having 2.3 MW of rated power is studied. The objective of this study is investigating the full three-dimensional wind field and the impact of three-dimensionality on the evolution of the waked area between nearby turbines. A post-processing method of the output of the CFD simulation is developed and this allows to estimate the wake lateral deviation and the wake width. The reliability of the numerical approach is inspired by and crosschecked through the analysis of the operational SCADA (Supervisory Control and Data Acquisition) data of the cluster of interest.