TWILIGHT: A Cellular Framework for Three-Dimensional Radiative Transfer
Khatami, David; Madore, Barry
2015-01-01
We describe a new framework for solving three-dimensional radiative transfer of arbitrary geometries, including a full characterisation of the wavelength-dependent anisotropic scattering, absorption, and thermal reemission of light by dust. By adopting a cellular approach to discretising the light and dust, the problem can be efficiently solved through a fully deterministic iterative process. As a proof of concept we present TWILIGHT, our implementation of the cellular approach, in order to demonstrate and benchmark the new method. TWILIGHT simultaneously renders over one hundred unique images of a given environment with no additional slowdown, enabling a close study of inclination effects of three-dimensional dust geometries. In addition to qualitative rendering tests, TWILIGHT is successfully tested against two Monte-Carlo radiative transfer benchmarks, producing similar brightness profiles at varying inclinations. With the proof-of-concept established, we describe the improvements and current developments underway using the cellular framework, including a technique to resolve the subgrid physics of dust radiative transfer from micron-scale grain models to kiloparsec-sized dust environments.
Xin, Shengchang; Yang, Na; Gao, Fei; Zhao, Jing; Li, Liang; Teng, Chao
2017-08-01
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.
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.
Li, Zonglong; Li, Hui; Guan, Xinyu; Tang, Junjie; Yusran, Yusran; Li, Zhan; Xue, Ming; Fang, Qianrong; Yan, Yushan; Valtchev, Valentin; Qiu, Shilun
2017-12-13
Covalent organic frameworks (COFs) have emerged as functional materials for various potential applications. However, the availability of three-dimensional (3D) COFs is still limited, and nearly all of them exhibit neutral porous skeletons. Here we report a general strategy to design porous positively charged 3D ionic COFs by incorporation of cationic monomers in the framework. The obtained 3D COFs are built of 3-fold interpenetrated diamond net and show impressive surface area and CO2 uptakes. The ion-exchange ability of 3D ionic COFs has been highlighted by reversible removal of nuclear waste model ions and excellent size-selective capture for anionic pollutants. This research thereby provides a new perspective to explore 3D COFs as a versatile type of ion-exchange materials.
A multifunctional chemical sensor based on a three-dimensional lanthanide metal-organic framework
Energy Technology Data Exchange (ETDEWEB)
Du, Pei-Yao [College of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE), Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071 (China); Liao, Sheng-Yun [Department of Applied Chemistry, Tianjin University of Technology, Tianjin 300384 (China); Gu, Wen, E-mail: guwen68@nankai.edu.cn [College of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE), Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071 (China); Liu, Xin, E-mail: liuxin64@nankai.edu.cn [College of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE), Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071 (China)
2016-12-15
A 3D lanthanide MOF with formula [Sm{sub 2}(abtc){sub 1.5}(H{sub 2}O){sub 3}(DMA)]·H{sub 2}O·DMA (1) has been successfully synthesized via solvothermal method. Luminescence studies reveal that 1 exhibits dual functional detection benzyl alcohol and benzaldehyde among different aromatic molecules. In addition, 1 displays a turn-on luminescence sensing with respect to ethanol among different alcohol molecules, which suggests that 1 is also a promising luminescent probe for high selective sensing of ethanol. - Highlights: • A three-dimensional lanthanide metal-organic framework has been synthesized. • Complex 1 exhibits dual functional detection benzyl alcohol and benzaldehyde among different aromatic molecules. • Complex 1 displays a turn-on luminescence sensing with respect to ethanol among different alcohol molecules.
Porous Uranyl Borophosphates with Unique Three-Dimensional Open-Framework Structures.
Hao, Yucheng; Murphy, Gabriel L; Bosbach, Dirk; Modolo, Giuseppe; Albrecht-Schmitt, Thomas E; Alekseev, Evgeny V
2017-08-07
Two novel alkali-metal uranyl borophosphates have been prepared and characterized for the first time, namely, K5(UO2)2[B2P3O12(OH)]2(OH)(H2O)2 and K2(UO2)12[B(H2PO4)4](PO4)8(OH)(H2O)6 denoted as KUPB1 and KUPB2, respectively. KUPB1 was obtained hydrothermally at 220 °C and crystallizes in a monoclinic structure in the chiral space group P21. The unit cell parameters of KUPB1 are a = 6.7623(2) Å, b = 19.5584(7) Å, c = 11.0110(4) Å, α = γ = 90°, β = 95.579(3)°, and V = 1449.42(8) Å3. It features a unique three-dimensional (3D) open-framework structure, composed of two corner-sharing linked one-dimensional (1D) anionic borophosphates (BP), [B2P3O13]5-, along the a axis and uranyl phosphate (UP), [(UO2)(PO4)3]7-, chains along the c axis, further bridged by PO4 tetrahedra. Multi-intersectional channels can be observed within the structure, in which the largest 11-ring (11-R) tunnel size is ∼7.0 Å × 8.8 Å. Its simplified framework can be described as a new 4-nodal net topological type with a point symbol of {4.84.10}{42.6}2{43.62.83.102}{82.10}. By modification of the synthetic conditions of KUPB1 through an increase in the amount of H3BO3 as flux 4-fold and a reduction of water as the reaction medium, the novel compound KUPB2 is generated. The unit cell parameters of KUPB2 are a = b = 21.8747(3) Å, c = 7.0652(2) Å, α = β = γ = 90°, and V = 3380.72(12) Å3. KUPB2 crystallizes in a tetragonal structure in the polar space group I4̅2m, and its structure is based on a highly complex 3D framework, {(UO2)12[B(PO4)4](PO4)8}9-, in which 1D 8-R UP [(UO2)(PO4)]- tubes can be observed along the c axis. The [(UO2)(PO4)]- tubes consist of three uranyl chains along the c axis, which are linked alternately by [PO4]3- tetrahedra. Those isolated 1D [(UO2)(PO4)]- tubes are further bridged through [(UO2)4B(PO4)4]- clusters, forming an exceptional 3D open-framework structure. Its simplified cation network is a new 5-nodal net topological type such as {32.43.5.62.7.8}8
Huang, Da; Yang, Zhi; Li, Xiaolin; Zhang, Liling; Hu, Jing; Su, Yanjie; Hu, Nantao; Yin, Guilin; He, Dannong; Zhang, Yafei
2017-01-07
Graphene is an ideal candidate for gas sensing due to its excellent conductivity and large specific surface areas. However, it usually suffers from sheet stacking, which seriously debilitates its sensing performance. Herein, we demonstrate a three-dimensional conductive network based on stacked SiO2@graphene core-shell hybrid frameworks for enhanced gas sensing. SiO2 spheres are uniformly encapsulated by graphene oxide (GO) through an electrostatic self-assembly approach to form SiO2@GO core-shell hybrid frameworks, which are reduced through thermal annealing to establish three-dimensional (3D) conductive sensing networks. The SiO2 supported 3D conductive graphene frameworks reveal superior sensing performance to bare reduced graphene oxide (RGO) films, which can be attributed to their less agglomeration and larger surface area. The response value of the 3D framework based sensor for 50 ppm NH3 and 50 ppm NO2 increased 8 times and 5 times, respectively. Additionally, the sensing performance degradation caused by the stacking of the sensing materials is significantly suppressed because the graphene layers are separated by the SiO2 spheres. The sensing performance decays by 92% for the bare RGO films when the concentration of the sensing material increases 8 times, while there is only a decay of 25% for that of the SiO2@graphene core-shell hybrid frameworks. This work provides an insight into 3D frameworks of hybrid materials for effectively improving gas sensing performance.
Thiophene, Selenophene, and Tellurophene-based Three-Dimensional Organic Frameworks.
Li, Peng-Fei; Schon, Tyler B; Seferos, Dwight S
2015-08-03
3D frameworks are important because of their potential to combine the advantageous properties of porous materials with those associated with polymers. A series of novel 3D aromatic frameworks are presented that incorporate the heterocycles thiophene, selenophene, and tellurophene. The specific surface area and pore width of frameworks depends on the element that is used to build the framework. Optoelectronic properties are element-dependent, with heavy atoms red-shifting the optical properties and decreasing the energy gap of the solid. The metalloid nature of tellurophene allows the properties of this material to be tuned based on its oxidation state, even as an insoluble solid. The incorporation of the optoelectronic active thiophene, selenophene, and tellurophene units and the effect that they have on properties was studied. A supercapcitor device was fabricated using these frameworks, showing that these 3D frameworks are promising for optoelectronic uses. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Miura, Shoko; Kasahara, Shin; Yamauchi, Shinobu; Egusa, Hiroshi
2017-06-01
The purpose of this study were: to perform stress analyses using three-dimensional finite element analysis methods; to analyze the mechanical stress of different framework designs; and to investigate framework designs that will provide for the long-term stability of both cantilevered fixed partial dentures (FPDs) and abutment teeth. An analysis model was prepared for three units of cantilevered FPDs that assume a missing mandibular first molar. Four types of framework design (Design 1, basic type; Design 2, framework width expanded buccolingually by 2 mm; Design 3, framework height expanded by 0.5 mm to the occlusal surface side from the end abutment to the connector area; and Design 4, a combination of Designs 2 and 3) were created. Two types of framework material (yttrium-oxide partially stabilized zirconia and a high precious noble metal gold alloy) and two types of abutment material (dentin and brass) were used. In the framework designs, Design 1 exhibited the highest maximum principal stress value for both zirconia and gold alloy. In the abutment tooth, Design 3 exhibited the highest maximum principal stress value for all abutment teeth. In the present study, Design 4 (the design with expanded framework height and framework width) could contribute to preventing the concentration of stress and protecting abutment teeth. © 2017 Eur J Oral Sci.
A surfactant-thermal method to prepare four new three-dimensional heterometal-organic frameworks
Gao, Junkuo
2013-01-01
Here, we report on a surfactant-thermal method to prepare four new 3-D crystalline heterometal-organic frameworks (HMOFs). The results indicate that our new strategy for growing crystalline materials in surfactant media has great potential for the synthesis of novel MOFs with various structures. © 2013 The Royal Society of Chemistry.
Three-dimensional metal-intercalated covalent organic frameworks for near-ambient energy storage
Gao, Fei; Ding, Zijing; Meng, Sheng
2013-01-01
A new form of nanoporous material, metal intercalated covalent organic framework (MCOF) is proposed and its energy storage property revealed. Employing density functional and thermodynamical analysis, we find that stable, chemically active, porous materials could form by stacking covalent organic framework (COF) layers with metals as a gluing agent. Metal acts as active sites, while its aggregation is suppressed by a binding energy significantly larger than the corresponding cohesive energy of bulk metals. Two important parameters, metal binding and metal-metal separation, are tuned by selecting suitable building blocks and linkers when constructing COF layers. Systematic searches among a variety of elements and organic molecules identify Ca-intercalated COF with diphenylethyne units as optimal material for H2 storage, reaching a striking gravimetric density ~ 5 wt% at near-ambient conditions (300 K, 20 bar), in comparison to < 0.1 wt% for bare COF-1 under the same condition. PMID:23698018
Wang, Zongyuan; Wang, Jiajun; Li, Minyue; Sun, Kaihang; Liu, Chang-jun
2014-01-01
Three-dimensional (3D) printing was applied for the fabrication of acrylonitrile butadiene styrene (ABS) framework. Functionalization of the ABS framework was then performed by coating of porous Cu-BTC (BTC = benzene tricarboxylic acid) metal-organic frameworks on it using a step-by-step in-situ growth. The size of the Cu-BTC particles on ABS was ranged from 200 nm to 900 nm. The Cu-BTC/ABS framework can take up most of the space of the tubular reactor that makes the adsorption effective with...
Czech Academy of Sciences Publication Activity Database
Roth, Wieslaw Jerzy; Shvets, O. V.; Shamzhy, M.; Eliášová, Pavla; Kubů, Martin; Nachtigall, P.; Čejka, Jiří
2011-01-01
Roč. 133, č. 16 (2011), s. 6130-6133 ISSN 0002-7863 R&D Projects: GA AV ČR KAN100400701; GA ČR GA104/09/0561; GA ČR GA203/08/0604; GA ČR GD203/08/H032 Institutional research plan: CEZ:AV0Z40400503 Keywords : postsynthesis transformation * zeolites * UTL framework Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 9.907, year: 2011
Large-Pore Mesoporous Silica with Three-Dimensional Wormhole Framework Structures.
Park, In; Pinnavaia, Thomas J
2009-02-01
Large-pore mesoporous silica with 3D wormhole framework structures (denoted MSU-J) are prepared through a supramolecular hydrogen-bonding assembly pathway from low-cost sodium silicate as the silica source and commercially available mono- and triamine Jeffamine and Surfonamine surfactants as structure-directing porogens. The calcined mesostructures exhibit large pore sizes (up to 8.2 nm), surface areas (632-1030 m(2)/g) and pore volumes (0.5-2.0 cm(3)/g), depending on the surfactant chain length and synthesis temperature (25-65 °C). The textural properties of these new wormhole mesostructures are comparable to those of hexagonal SBA-15 derivatives and large pore MCM-48. However, unlike the SBA-15 structure type, wherein the 3D pore network is formed by connecting 1D cylindrical mesopores through micropores, MSU-J mesophases have wormhole framework structures containing fully interconnected 3D mesopores that can minimize the diffusion limitations often encountered in adsorption and chemical catalysis. Also, unlike large pore MCM-48, which requires cost-intensive tetraethylorthosilicate as a silica source and the use of a co-surfactant as a pore expander under strong acid conditions, MSU-J mesostructures are assembled from low cost sodium silicate in the presence of a single Jeffamine or Surfonamine porogen at near-neutral pH.
A three-dimensional metal–organic framework for selective sensing of nitroaromatic compounds
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Dan Tian
2014-12-01
Full Text Available A 3D metal–organic framework [NH2(CH32][Cd6(L4(DMF6(HCOO](DMF = N,N-dimethylformamide (1 has been synthesized using a tripodal ligand H3L (2,4,6-tris[1-(3-carboxylphenoxyylmethyl]mesitylene. The obtained complex exhibits a 3D framework containing hexanuclear {Cd6} building units formed by two trinuclear {Cd3} clusters that are connected via HCOO− anions. For complex 1, the participation of the fluorescent ligand H3L not only gives rise to a strong photoluminescence emission as expected, but more interestingly, that ligand originated characteristic band could be quenched selectively by nitrobenzene with a low detection limit, showing its potential as a highly sensitive and selective sensor for nitrobenzene. Based on an electron transfer quenching mechanism, the fluorescence sensing ability of 1 is also applicable for other electron-deficient nitroaromatic compounds with high selectivity and sensitivity, i.e., 1,4-dinitrobenzene, 1,3-dinitrobenzene, 2,4-dinitrotoluene, and 4-nitrotoluene, suggesting 1 a promising fluorescence sensor for detecting and recognizing the same kind of chemicals.
Directory of Open Access Journals (Sweden)
Young Soo Kim
2013-05-01
Full Text Available BackgroundTo construct a sophisticated three-dimensional framework, numerous modifications have been reported in the literature. However, most surgeons have paid little attention to the anatomical configuration of the concha and more to its deepness and hollowness, leading to unsatisfactory outcomes.MethodsFor a configuration of the concha that is definitely anatomical, the author further developed and employed the conchal bowl element, which has been used by several surgeons although the results have not been published elsewhere. The author constructed the conchal bowl element in one of three patterns according to the amount of available cartilages: one block, two-pieces, or a cymba bowl element only. A total of 20 patients underwent auricular reconstruction using a costal cartilage framework between 2009 and 2012. The 8 earliest reconstructions were performed without a conchal bowl element and the latter 12 with a conchal bowl element. The patients were followed up for more than 1 year. The aesthetic results were scored by evaluating characteristics involving the stability of the crus helicis, the conchal definition, and the smoothness of the helical curve.ResultsThe ears reconstructed early without a conchal bowl element showed a shallow and one or two incompletely separated concha with an obliterated cymba conchal space. They also did not have a realistic or smooth curve of the helix because of an unstable crus helicis. However, ears reconstructed later with the concha bowl element showed a definite crus helicis, deep cymba conchal space, and smooth helical curve.ConclusionsThe construction of the conchal bowl element is simple, not time-consuming procedure. It is suggested that the conchal bowl element must be constructed and attached to the main framework for natural configuration of the reconstructed ear.
Tanaka, Manabu; Takeda, Yasushi; Wakiya, Takeru; Wakamoto, Yuta; Harigaya, Kaori; Ito, Tatsunori; Tarao, Takashi; Kawakami, Hiroyoshi
2017-02-01
High-performance polymer electrolyte membranes (PEMs) with excellent proton conductivity, gas barrier property, and membrane stability are desired for future fuel cells. Here we report the development of PEMs based on our proposed new concept ;Nanofiber Framework (NfF).; The NfF composite membranes composed of phytic acid-doped polybenzimidazole nanofibers (PBINf) and Nafion matrix show higher proton conductivity than the recast-Nafion membrane without nanofibers. A series of analyses reveal the formation of three-dimensional network nanostructures to conduct protons and water effectively through acid-condensed layers at the interface of PBINf and Nafion matrix. In addition, the NfF composite membrane achieves high gas barrier property and distinguished membrane stability. The fuel cell performance by the NfF composite membrane, which enables ultra-thin membranes with their thickness less than 5 μm, is superior to that by the recast-Nafion membrane, especially at low relative humidity. Such NfF-based high-performance PEM will be accomplished not only by the Nafion matrix used in this study but also by other polymer electrolyte matrices for future PEFCs.
Wang, Zongyuan; Wang, Jiajun; Li, Minyue; Sun, Kaihang; Liu, Chang-Jun
2014-08-01
Three-dimensional (3D) printing was applied for the fabrication of acrylonitrile butadiene styrene (ABS) framework. Functionalization of the ABS framework was then performed by coating of porous Cu-BTC (BTC = benzene tricarboxylic acid) metal-organic frameworks on it using a step-by-step in-situ growth. The size of the Cu-BTC particles on ABS was ranged from 200 nm to 900 nm. The Cu-BTC/ABS framework can take up most of the space of the tubular reactor that makes the adsorption effective with no need of stirring. Methylene blue (MB) can be readily removed from aqueous solution by this Cu-BTC/ABS framework. The MB removal efficiency for solutions with concentrations of 10 and 5 mg/L was 93.3% and 98.3%, respectively, within 10 min. After MB adsorption, the Cu-BTC/ABS composite can easily be recovered without the need for centrifugation or filtration and the composite is reusable. In addition the ABS framework can be recovered for subsequent reuse. A significant advantage of 3D-printed frameworks is that different frameworks can be easily fabricated to meet the needs of different applications. This is a promising strategy to synthesize new frameworks using MOFs and polymers to develop materials for applications beyond adsorption.
Wang, Zongyuan; Wang, Jiajun; Li, Minyue; Sun, Kaihang; Liu, Chang-jun
2014-08-04
Three-dimensional (3D) printing was applied for the fabrication of acrylonitrile butadiene styrene (ABS) framework. Functionalization of the ABS framework was then performed by coating of porous Cu-BTC (BTC = benzene tricarboxylic acid) metal-organic frameworks on it using a step-by-step in-situ growth. The size of the Cu-BTC particles on ABS was ranged from 200 nm to 900 nm. The Cu-BTC/ABS framework can take up most of the space of the tubular reactor that makes the adsorption effective with no need of stirring. Methylene blue (MB) can be readily removed from aqueous solution by this Cu-BTC/ABS framework. The MB removal efficiency for solutions with concentrations of 10 and 5 mg/L was 93.3% and 98.3%, respectively, within 10 min. After MB adsorption, the Cu-BTC/ABS composite can easily be recovered without the need for centrifugation or filtration and the composite is reusable. In addition the ABS framework can be recovered for subsequent reuse. A significant advantage of 3D-printed frameworks is that different frameworks can be easily fabricated to meet the needs of different applications. This is a promising strategy to synthesize new frameworks using MOFs and polymers to develop materials for applications beyond adsorption.
First, Eric L; Gounaris, Chrysanthos E; Floudas, Christodoulos A
2013-05-07
With the growing number of zeolites and metal-organic frameworks (MOFs) available, computational methods are needed to screen databases of structures to identify those most suitable for applications of interest. We have developed novel methods based on mathematical optimization to predict the shape selectivity of zeolites and MOFs in three dimensions by considering the energy costs of transport through possible pathways. Our approach is applied to databases of over 1800 microporous materials including zeolites, MOFs, zeolitic imidazolate frameworks, and hypothetical MOFs. New materials are identified for applications in gas separations (CO2/N2, CO2/CH4, and CO2/H2), air separation (O2/N2), and chemicals (propane/propylene, ethane/ethylene, styrene/ethylbenzene, and xylenes).
Directory of Open Access Journals (Sweden)
Chih-Chieh Wang
2017-11-01
Full Text Available Assemblies of four three-dimensional (3D mixed-ligand coordination polymers (CPs having formulas, {[Zn2(bdc2(4-bpdh]·C2H5OH·2H2O}n (1, [Zn(bdc(4-bpdh]n (2, {[Zn2(bdc2(4-bpdh2]·(4-bpdh}n (3, and {[Zn(bdc(4-bpdh]·C2H5OH}n (4 (bdc2− = dianion of 1,4-benzenedicarboxylic acid, 4-bpdh = 2,5-bis(4-pyridyl-3,4-diaza-2,4-hexadiene have been synthesized and structurally characterized by single-crystal X-ray diffraction method. Structural determination reveals that the coordination numbers (geometry of Zn(II ions in 1, 2, 3, and 4 are five (distorted square-pyramidal (SP, six (distorted octahedral (Oh, five (trigonal-bipyramidal (TBP, and four (tetrahedral (Td, respectively, and are bridged by 4-bpdh with bis-monodentate coordination mode and bdc2− ligands with bis-bidentate in 1, chelating/bidentate in 2, bis-monodentate and bis-bidentate in 3, and bis-monodentate in 4, to generate two-fold interpenetrating 3D cube-like metal-organic framework (MOF with pcu topology, non-interpenetrating 3D MOF, two-fold interpenetrating 3D rectangular-box-like MOF with pcu topology and five-fold interpenetrating diamondoid-like MOF with dia topology, respectively. These different intriguing architectures indicate that the coordination numbers and geometries of Zn(II ions, coordination modes of bdc2− ligand, and guest molecules play important roles in the construction of MOFs and the formation of the structural topologies and interpenetrations. Thermal stabilities, and photoluminescence study of 1–4 were also studied in detail. The complexes exhibit ligands based photoluminescence properties at room temperature.
Du, Pei-Yao; Gu, Wen; Liu, Xin
2016-08-15
A multifunctional three-dimensional lanthanide metal-organic framework has been rationally constructed. Highly selective sensing of benzaldehyde and Cu(2+) ions makes it a potential bifunctional sensor. Also, it could serve as a good candidate material for the removal of dyes from effluents based on the size exclusion.
Pantea, Michael P.; Cole, James C.
2004-01-01
This report describes a digital, three-dimensional faulted hydrostratigraphic model constructed to represent the geologic framework of the Edwards aquifer system in the area of San Antonio, northern Bexar County, Texas. The model is based on mapped geologic relationships that reflect the complex structures of the Balcones fault zone, detailed lithologic descriptions and interpretations of about 40 principal wells (and qualified data from numerous other wells), and a conceptual model of the gross geometry of the Edwards Group units derived from prior interpretations of depositional environments and paleogeography. The digital model depicts the complicated intersections of numerous major and minor faults in the subsurface, as well as their individual and collective impacts on the continuity of the aquifer-forming units of the Edwards Group and the Georgetown Formation. The model allows for detailed examination of the extent of fault dislocation from place to place, and thus the extent to which the effective cross-sectional area of the aquifer is reduced by faulting. The model also depicts the internal hydrostratigraphic subdivisions of the Edwards aquifer, consisting of three major and eight subsidiary hydrogeologic units. This geologic framework model is useful for visualizing the geologic structures within the Balcones fault zone and the interactions of en-echelon fault strands and flexed connecting fault-relay ramps. The model also aids in visualizing the lateral connections between hydrostratigraphic units of relatively high and low permeability across the fault strands. Introduction The Edwards aquifer is the principal source of water for municipal, agricultural, industrial, and military uses by nearly 1.5 million inhabitants of the greater San Antonio, Texas, region (Hovorka and others, 1996; Sharp and Banner, 1997). Discharges from the Edwards aquifer also support local recreation and tourism industries at Barton, Comal, and San Marcos Springs located
Sweetkind, Donald S.
2017-09-08
As part of a U.S. Geological Survey study in cooperation with the Bureau of Reclamation, a digital three-dimensional hydrogeologic framework model was constructed for the Rio Grande transboundary region of New Mexico and Texas, USA, and northern Chihuahua, Mexico. This model was constructed to define the aquifer system geometry and subsurface lithologic characteristics and distribution for use in a regional numerical hydrologic model. The model includes five hydrostratigraphic units: river channel alluvium, three informal subdivisions of Santa Fe Group basin fill, and an undivided pre-Santa Fe Group bedrock unit. Model input data were compiled from published cross sections, well data, structure contour maps, selected geophysical data, and contiguous compilations of surficial geology and structural features in the study area. These data were used to construct faulted surfaces that represent the upper and lower subsurface hydrostratigraphic unit boundaries. The digital three-dimensional hydrogeologic framework model is constructed through combining faults, the elevation of the tops of each hydrostratigraphic unit, and boundary lines depicting the subsurface extent of each hydrostratigraphic unit. The framework also compiles a digital representation of the distribution of sedimentary facies within each hydrostratigraphic unit. The digital three-dimensional hydrogeologic model reproduces with reasonable accuracy the previously published subsurface hydrogeologic conceptualization of the aquifer system and represents the large-scale geometry of the subsurface aquifers. The model is at a scale and resolution appropriate for use as the foundation for a numerical hydrologic model of the study area.
Liao, Kexuan; Gao, Jialu; Fan, Jinchen; Mo, Yao; Xu, Qunjie; Min, Yulin
2017-12-01
In this work, novel three-dimensional (3D) boron and nitrogen-co-doped three-dimensional (3D) graphene frameworks (BN-GFs) supporting rod-like polyaniline (PANI) are facilely prepared and used as electrodes for high-performance supercapacitors. The results demonstrated that BN-GFs with tuned electronic structure can not only provide a large surface area for rod-like PANI to anchor but also effectively facilitate the ion transfer and charge storage in the electrode. The PANI/BN-GF composite with wrinkled boron and nitrogen-co-doped graphene sheets interconnected by rod-like PANI exhibits excellent capacitive properties with a maximum specific capacitance of 596 F/g at a current density of 0.5 A/g. Notably, they also show excellent cycling stability with more than 81% capacitance retention after 5000 charge-discharge cycles.
Bennis, Anne-Claire; Ardhuin, Fabrice; Dumas, Franck
Many theoretical approaches and implementations have been proposed for the coupling of the three-dimensional ocean circulation with waves. The theoretical models are reviewed and it is shown that the formulation in terms of the quasi-Eulerian velocity circumvents the essential difficulty of alternative formulations for the Lagrangian mean velocity. Namely, models based on this Lagrangian velocity require an estimation of wave-induced motions to first order in the horizontal gradients of the wave field in order to estimate the vertical flux of wave pseudo-momentum. So far, only three-dimensional wave models have been able to provide these estimates, and all published theories based on the simpler Airy theory are not consistent at the leading order, because they ignore or incorrectly estimate the vertical momentum flux. With an adiabatic example on a sloping bottom it is shown that this inconsistency produces very large spurious velocities. These errors are independent of the slope for the inviscid case, and are still significant when a realistic vertical mixing is applied. A quick diagnostic of the potential accuracy of a theoretical model is the vertical profile of the wave-induced forcing terms: if it is not uniform over depth in adiabatic conditions then it will produce spurious artificial flow patterns in conditions with shoaling waves. Although conceptually more challenging, the quasi-Eulerian velocity theories only introduce minor modifications of the solution procedure for the standard primitive equations: a modification of the surface boundary condition for the mass conservation, the addition of the Stokes drift in the tracer advection equations, and sources of momentum and turbulent kinetic energy with associated surface and bottom fluxes. All the necessary modifications of primitive equation models are given in detail. This implementation is illustrated with the MARS3D model, which passes the test of the adiabatic shoaling waves.
Zhou, Weijia; Zhou, Kai; Hou, Dongman; Liu, Xiaojun; Li, Guoqiang; Sang, Yuanhua; Liu, Hong; Li, Ligui; Chen, Shaowei
2014-12-10
Advanced materials for electrocatalytic water splitting are central to renewable energy research. In this work, three-dimensional (3D) hierarchical frameworks based on the self-assembly of MoS2 nanosheets on graphene oxide were produced via a simple one-step hydrothermal process. The structures of the resulting 3D frameworks were characterized by using a variety of microscopic and spectroscopic tools, including scanning and transmission electron microscopies, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman scattering. Importantly, the three-dimensional MoS2/graphene frameworks might be used directly as working electrodes which exhibited apparent and stable electrocatalytic activity in hydrogen evolution reaction (HER), as manifested by a large cathodic current density with a small overpotential of -107 mV (-121 mV when loaded on a glassy-carbon electrode) and a Tafel slope of 86.3 mV/dec (46.3 mV/dec when loaded on a glassy-carbon electrode). The remarkable performance might be ascribed to the good mechanical strength and high electrical conductivity of the 3D frameworks for fast charge transport and collection, where graphene oxide provided abundant nucleation sites for MoS2 deposition and oxygen incorporation led to the formation of defect-rich MoS2 nanosheets with active sites for HER.
Meyer, Scott C; Lin, Yu-Feng; Roadcap, George S
2012-01-01
We employed the ArcGIS plug-in package PRO-GRADE (Lin et al. 2009), developed for zonation of recharge/discharge (R/D) for modeling two-dimensional aquifer systems, to develop alternative R/D zonations for an existing three-dimensional groundwater flow model of a complex hydrogeologic setting. Our process began by intersecting PRO-GRADE output with the existing model's 4-zone R/D representation to develop a model having 12 R/D zones (R12) and then calibrating the resulting model using PEST. We then revised the R12 zonation using supplementary GIS data to develop a 51-zone R/D zonation (R51). From R51, we developed a series of daughter models having 40, 30, 28, and 18 R/D zones by removing zones from R51 if calibration resulted in little change in the zone's starting R/D rate and/or if the model was insensitive to the zone's R/D rate. For these models (R40N, R30N, R28N, and R18N), we used the ArcGIS Nibble tool to rapidly and consistently reassign model cells within eliminated zones of R51 to the zone of the nearest model cell in a retained zone having the same starting value. R12, R51, R40N, R30N, R28N, and R18N are all more accurate than the original model (R4), although improvements relative to stream discharge targets exceeded improvements relative to head targets. The models also executed with better numerical stability and less mass balance discrepancy than R4. These improvements demonstrate that R/D estimation in a complex shallow three-dimensional steady-state model can be improved with PRO-GRADE estimates of R/D when guided by calibration statistics and supplemental geographic data. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.
Dang, Dong-Bin; An, Bing; Bai, Yan; Zheng, Guang-Shui; Niu, Jing-Yang
2013-03-18
A series of 3D homochiral manganese-lanthanide frameworks have been synthesized based on chiral camphoric acid. In the heterometallic features, D-camphoric acids are unprecedentedly embedded in three coordination modes.
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Goswami, Subhadip; Ma, Lin; Martinson, Alex B. F.; Wasielewski, Michael R.; Farha, Omar K.; Hupp, Joseph T.
2016-11-16
Owing to their ability to act as light-harvesting scaffolds, porphyrin-containing metal-organic frameworks (MOFs) are in the forefront of research on the application of highly ordered molecular materials to problems in solar-energy conversion. In this work, solvent-assisted linker exchange (SALE) is performed on a pillared paddlewheel porphyrin containing MOF thin film to collapse a 3D framework to a 2D framework. The change in dimensionality of the framework is confirmed by a decrease in the film thickness, the magnitude of which is in agreement with crystallographic parameters for related bulk materials. Furthermore, NMR spectroscopy performed on the digested sample suggests a similar change in geometry is achieved in bulk MOF samples. The decreased distance between the porphyrin chromophores in the 2D MOF film compared to the 3D film results in enhanced energy transfer through the film. The extent of energy transport was probed by assembling MOF thin film where the outermost layers are palladium porphyrin (P2) units, which act as energy traps and fluorescence quenchers. Steady-state emission spectroscopy together with time-resolved emission spectroscopy indicates that excitons can travel through about 9-11 layers (porphyrin layers) in 2D films, whereas in 3D films energy transfer occurs through no more than about 6-8 layers. The results are difficult to understand if only changes in MOF interlayer spacing are considered but become much more understandable if dipole-dipole coupling distances are considered.
Sarangarajan, Thanjavur R; Krishnamoorthy, Belli S; Panchanatheswaran, Krishnaswamy; Low, John N; Glidewell, Christopher
2008-08-01
Compounds trans-tetraaquadichloridocobalt(II)-piperazine-2,5-dione (1/1), [CoCl(2)(H(2)O)(4)].C(4)H(6)N(2)O(2), (I), and trans-tetraaquadichloridonickel(II)-piperazine-2,5-dione (1/1), [NiCl(2)(H(2)O)(4)].C(4)H(6)N(2)O(2), (II), are isomorphous. In each structure, the metal complex and the piperazinedione unit both lie across centres of inversion in the space group P2(1)/n. The [MCl(2)(H(2)O)(4)] units (M = Co or Ni) are linked by O-H...Cl hydrogen bonds into sheets of R(2)(2)(8) and R(4)(2)(12) rings, and these sheets are linked by the piperazinedione components via a combination of O-H...O and N-H...Cl hydrogen bonds into a three-dimensional framework. In catena-poly[[[trans-diaquacopper(II)]-di-mu-chlorido] piperazine-2,5-dione solvate], {[CuCl(2)(H(2)O)(2)].C(4)H(6)N(2)O(2)}(n), (III), the metal ion and the piperazine unit both lie across centres of inversion in the space group I2/a. The coordination polymer forms chains of centrosymmetric [CuCl(2)(H(2)O)(2)] units running parallel to [010] and these are linked by the piperazinedione units into a three-dimensional framework structure. In poly[mu(3)-nitrato-mu(2)-piperazine-2,5-dione-silver(I)], [Ag(NO(3))(C(4)H(6)N(2)O(2))](n), (IV), the silver and nitrate ions lie on mirror planes in the space group Pnma, while the piperazinedione unit lies across a centre of inversion. The compound is a coordination polymer containing five-coordinate approximately square-pyramidal Ag, in which the ligating O atoms are derived from three different nitrate ligands and two different piperazinedione ligands. The ionic components form sheets in which each anion is coordinated to three different cations, and these sheets are linked into a three-dimensional framework by the organic ligands, each of which coordinates to two different Ag centres. The significance of this study lies in its demonstration of a wide variety of framework types built from a common and very simple organic component with simple metal salts.
Lu, Wen-Guan; Jiang, Long; Feng, Xiao-Long; Lu, Tong-Bu
2009-08-03
Three 3D lanthanide anionic metal-organic frameworks {K(5)[Ln(5)(IDC)(4)(ox)(4)]}(n) x (20H(2)O)(n) with 1D channels were synthesized under hydrothermal conditions [Ln = Gd (1), Tb (2), and Dy (3)]. The K(+) ions within the 1D channel are easily exchanged with various cations. The emission intensities of Tb(III) in 2 increased significantly upon the addition of Ca(2+) ions, while the introduction of other metal ions caused the intensities to be either unchanged or weakened.
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Young Soo Kim
2013-05-01
Full Text Available Background To construct a sophisticated three-dimensionalframework, numerousmodifications have been reported in the literature. However, mostsurgeons have paid little attentionto the anatomical configuration of the concha and more to its deepness and hollowness,leading to unsatisfactory outcomes.Methods For a configuration ofthe concha thatis definitely anatomical,the authorfurtherdeveloped and employed the conchal bowl element,which has been used by severalsurgeonsalthough the results have not been published elsewhere. The author constructed the conchalbowl element in one of three patterns according to the amount of available cartilages: oneblock,two-pieces, or a cymba bowl element only. A total of 20 patients underwent auricularreconstruction using a costal cartilage framework between 2009 and 2012. The 8 earliestreconstructionswere performedwithout a conchal bowl element and the latter 12with a conchalbowl element. The patientswere followed up for more than 1 year. The aesthetic resultswerescored by evaluating characteristicsinvolving the stability ofthe crus helicis,the conchal definition, and the smoothness ofthe helical curve.Results The earsreconstructed earlywithout a conchal bowl elementshowed a shallowandone or two incompletely separated concha with an obliterated cymba conchal space. Theyalso did not have a realistic orsmooth curve ofthe helix because of an unstable crus helicis.However, earsreconstructed laterwith the concha bowl elementshowed a definite crus helicis,deep cymba conchalspace, and smooth helical curve.Conclusions The construction of the conchal bowl element is simple, not time-consumingprocedure. It is suggested that the conchal bowl element must be constructed and attachedto themain framework for natural configuration ofthe reconstructed ear.
Fang, Zhen-Lan; Yu, Rong-Min; He, Jian-Gang; Zhang, Qi-Sheng; Zhao, Zhen-Guo; Lu, Can-Zhong
2009-08-17
Three novel microporous three-dimensional (3-D) metal-organic framework materials [ML](n) [M = Ni, Co, Cd; L = N,N'-bis(4-picolinoyl)hydrazine] were obtained from hydrothermal reactions. The organic ligand L was formed through the in situ ring-opening hydrolysis reaction of 2,5-bis(4-pyridyl)-1,3,4-oxadiazole with the assistance of metal ions. Single-crystal X-ray diffraction studies reveal that complexes 1-3 adopt 6-connected 3-D networks of distorted alpha-Po topology, which are built from non-interpenetrated (4,4) grids cross-linked by zigzag chains. These isomorphic complexes are all of high thermal stability, but some other physical properties are quite different because of their different metal centers. Antiferromagnetic exchange was observed between Ni(II) centers of complex 1, while ferromagnetic for Co(II) centers of complex 2. Complex 3 exhibits strong fluorescence emission.
Reade, Thomas J.; Murphy, Thomas S.; Calladine, James A.; Horvath, Raphael; Clark, Ian P.; Greetham, Gregory M.; Towrie, Michael; Lewis, William; George, Michael W.
2017-01-01
The structures and photochemical behaviour of two new metal–organic frameworks (MOFs) are reported. Reaction of Re(2,2′-bipy-5,5′-dicarboxylic acid)(CO)3Cl or Mn(2,2′-bipy-5,5′-dicarboxylic acid)(CO)3Br with LiCl or LiBr, respectively, produces single crystals of {Li2(DMF)2 [(2,2′-bipy-5,5′-dicarboxylate)Re(CO)3Cl]}n (ReLi) or {Li2(DMF)2[(2,2′-bipy-5,5′-dicarboxylate)Mn(CO)3Br]}n (MnLi). The structures formed by the two MOFs comprise one-dimensional chains of carboxylate-bridged Li(I) cations that are cross-linked by units of Re(2,2′-bipy-5,5′-dicarboxylate)(CO)3Cl (ReLi) or Mn(2,2′-bipy-5,5′- dicarboxylate)(CO)3Br (MnLi). The photophysical and photochemical behaviour of both ReLi and MnLi are probed. The rhenium-containing MOF, ReLi, exhibits luminescence and the excited state behaviour, as established by time-resolved infrared measurements, is closer in behaviour to that of unsubstituted [Re(bipy)(CO)3Cl] rather than a related MOF where the Li(I) cations are replaced by Mn(II) cations. These observations are further supported by density functional theory calculations. Upon excitation MnLi forms a dicarbonyl species which rapidly recombines with the dissociated CO, in a fashion consistent with the majority of the photoejected CO not escaping the MOF channels. This article is part of the themed issue ‘Coordination polymers and metal–organic frameworks: materials by design’. PMID:27895261
Reade, Thomas J; Murphy, Thomas S; Calladine, James A; Horvath, Raphael; Clark, Ian P; Greetham, Gregory M; Towrie, Michael; Lewis, William; George, Michael W; Champness, Neil R
2017-01-13
The structures and photochemical behaviour of two new metal-organic frameworks (MOFs) are reported. Reaction of Re(2,2'-bipy-5,5'-dicarboxylic acid)(CO) 3 Cl or Mn(2,2'-bipy-5,5'-dicarboxylic acid)(CO) 3 Br with LiCl or LiBr, respectively, produces single crystals of {Li 2 (DMF) 2 [(2,2'-bipy-5,5'-dicarboxylate)Re(CO) 3 Cl]} n ( RELI: ) or {Li 2 (DMF) 2 [(2,2'-bipy-5,5'-dicarboxylate)Mn(CO) 3 Br]} n ( MNLI: ). The structures formed by the two MOFs comprise one-dimensional chains of carboxylate-bridged Li(I) cations that are cross-linked by units of Re(2,2'-bipy-5,5'-dicarboxylate)(CO) 3 Cl ( RELI: ) or Mn(2,2'-bipy-5,5'- dicarboxylate)(CO) 3 Br ( MNLI: ). The photophysical and photochemical behaviour of both RELI: and MNLI: are probed. The rhenium-containing MOF, RELI: , exhibits luminescence and the excited state behaviour, as established by time-resolved infrared measurements, is closer in behaviour to that of unsubstituted [Re(bipy)(CO) 3 Cl] rather than a related MOF where the Li(I) cations are replaced by Mn(II) cations. These observations are further supported by density functional theory calculations. Upon excitation MNLI: forms a dicarbonyl species which rapidly recombines with the dissociated CO, in a fashion consistent with the majority of the photoejected CO not escaping the MOF channels.This article is part of the themed issue 'Coordination polymers and metal-organic frameworks: materials by design'. © 2016 The Author(s).
Zhao, Bing; Wang, Zhixuan; Chen, Fang; Yang, Yaqing; Gao, Yang; Chen, Lu; Jiao, Zheng; Cheng, Lingli; Jiang, Yong
2017-01-18
Three-dimensional (3D) interconnected spherical graphene framework-decorated SnS nanoparticles (3D SnS@SG) is synthesized by self-assembly of graphene oxide nanosheets and positively charged polystyrene/SnO2 nanospheres, followed by a controllable in situ sulfidation reaction during calcination. The SnS nanoparticles with diameters of ∼10-30 nm are anchored to the surface of the spherical graphene wall tightly and uniformly. Benefiting from the 3D interconnected spherical graphene framework and subtle SnS nanoparticles, the generated Li2S could keep in close contact with Sn to make possible the in situ conversion reaction SnS + 2Li(+) + 2e(-) ↔ Sn + Li2S. As a result, the 3D SnS@SG as the anode material for lithium ion batteries shows a high initial Coulombic efficiency of 75.3%. Apart from the irreversible capacity loss of 3D spherical graphene, the initial Coulombic efficiency of SnS in the 3D SnS@SG composite is as high as 99.7%, demonstrating the almost complete reversibility of Li2S in this system. Furthermore, it also exhibits an excellent reversible capacity (800 mAh g(-1) after 100 cycles at 0.1 C and 527.1 mAh g(-1) after 300 cycles at 1 °C) and outstanding rate capability (380 mAh g(-1) at 5 °C).
Gu, Xinyuan; Wu, Feilong; Lei, Bingbing; Wang, Jing; Chen, Ziliang; Xie, Kai; Song, Yun; Sun, Dalin; Sun, Lixian; Zhou, Huaiying; Fang, Fang
2016-07-01
Bamboo-like WO3 nanorods were anchored on three-dimensional nitrogen-doped graphene frameworks (r-WO3/3DNGF) by a facile one-step hydrothermal synthesis plus heating processes. There is a strong dependence of the obtained r-WO3/3DNGF nanostructures on the content of 3DNGF. The composite with 20 wt% 3DNGF content shows the most favorable structure where bamboo-like WO3 nanorods lie flat on the surface of fungus-like 3DNGF, and exhibits a high discharge capacity of 828 mAh g-1 over 100 cycles at 80 mA g-1 with the largest capacity retention of 73.9% for WO3 and excellent rate capacities of 719, 665, 573, 453 and 313 mAh g-1 at 80, 160, 400, 800 and 1600 mA g-1, respectively. The electrochemical performance is better than most of reported WO3-based carbonaceous composites, which can be attributed to the synergistic effects of the following actions: i) WO3 nanorods effectively shorten the diffusion path of Li+; ii) mechanically strong 3DNGF alleviates the huge volume change of WO3 upon Li+ intercalation/extraction; and iii) nitrogen-doping in 3D graphene frameworks improves electronic conductivity and provides large numbers of lithium ion diffusion channels.
Kwon, Hyuk-Tae; Lee, Churl Kyoung; Jeon, Ki-Joon; Park, Cheol-Min
2016-06-28
The development of an electrode material for rechargeable Li-ion batteries (LIBs) and the understanding of its reaction mechanism play key roles in enhancing the electrochemical characteristics of LIBs for use in various portable electronics and electric vehicles. Here, we report a three-dimensional (3D) crystalline-framework-structured silicon diphosphide (SiP2) and its interesting electrochemical behaviors for superior LIBs. During Li insertion in the SiP2, a three-step electrochemical reaction mechanism, sequentially comprised of a topotactic transition (0.55-2 V), an amorphization (0.25-2 V), and a conversion (0-2 V), was thoroughly analyzed. On the basis of the three-step electrochemical reaction mechanism, excellent electrochemical properties, such as high initial capacities, high initial Coulombic efficiencies, stable cycle behaviors, and fast-rate capabilities, were attained from the preparation of a nanostructured SiP2/C composite. This 3D crystalline-framework-structured SiP2 compound will be a promising alternative anode material in the realization and mass production of excellent, rechargeable LIBs.
Bacchi, Ataís; Consani, Rafael L X; Mesquita, Marcelo F; dos Santos, Mateus B F
2013-09-01
The purpose of this study was to evaluate the influence of superstructure material and vertical misfits on the stresses created in an implant-supported partial prosthesis. A three-dimensional (3-D) finite element model was prepared based on common clinical data. The posterior part of a severely resorbed jaw with two osseointegrated implants at the second premolar and second molar regions was modeled using specific modeling software (SolidWorks 2010). Finite element models were created by importing the solid model into mechanical simulation software (ANSYS Workbench 11). The models were divided into groups according to the prosthesis framework material (type IV gold alloy, silver-palladium alloy, commercially pure titanium, cobalt-chromium alloy, or zirconia) and vertical misfit level (10 µm, 50 µm, and 100 µm) created at one implant-prosthesis interface. The gap of the vertical misfit was set to be closed and the stress values were measured in the framework, porcelain veneer, retention screw, and bone tissue. Stiffer materials led to higher stress concentration in the framework and increased stress values in the retention screw, while in the same circumstances, the porcelain veneer showed lower stress values, and there was no significant difference in stress in the peri-implant bone tissue. A considerable increase in stress concentration was observed in all the structures evaluated within the misfit amplification. The framework material influenced the stress concentration in the prosthetic structures and retention screw, but not that in bone tissue. All the structures were significantly influenced by the increase in the misfit levels.
He, Jiarui; Lv, Weiqiang; Chen, Yuanfu; Xiong, Jie; Wen, Kechun; Xu, Chen; Zhang, Wanli; Li, Yanrong; Qin, Wu; He, Weidong
2017-09-01
Three-dimensional, porous graphitic carbon co-doped with cobalt and nitrogen (C-Co-N) is prepared with metal-organic framework (MOF) and employed as Lewis base matrix to host selenium. Owing to the unique structure with abundant micro/meso-pores, the highly-conductive C-Co-N matrix provides highly-efficient channels for electron transfer and ionic diffusion, and sufficient surface area for loading of selenium nanoparticles while mitigating dissolution of polyselenides and suppressing volume expansion. The homogenous distribution of cobalt nanoparticles and nitrogen-group in C-Co-N composite immobilize polyselenides through strong chemical interaction in the operation of Li-Se batteries. With a very high Se loading of 76.5 wt%, the C-Co-N/Se cathode delivers superior electrochemical performance with an ultrahigh reversible capacity of 672.3 mAh g-1 (99.6% of the theoretical value) and a capacity of 574.2 mAh g-1 after 200 cycles, giving a capacity fading of only 0.07% per cycle and a nearly 100% Columbic efficiency. In-situ Raman spectroscopy and density functional theory simulations are employed to investigate the Se (de)lithiation mechanism at the electrolyte/cathode interface, and confirm that the structure and composition of C-Co-N scaffold give rise to efficient cathode host for high-performance Se-based cathodes with dramatically reduced capacity fading.
Hill, M. C.; Belcher, W. R.; Sweetkind, D. S.; Faunt, C.
2014-12-01
The Death Valley regional groundwater flow system encompasses a proposed site for a high-level nuclear waste repository of the United States of America, the Nevada National Security Site (NNSS), where nuclear weapons were tested, and National Park and BLM properties, and provides water for local communities. The model was constructed using a three-dimensional hydrogeologic framework and has been used as a resource planning mechanism by the many stakeholders involved, including four United States (U.S) federal agencies (U.S. Department of Energy, National Park Service, Bureau of Land Management, and U.S. Fish and Wildlife Service) and local counties, towns, and residents. One of the issues in recent model development is simulation of insufficient water to regional discharge areas which form springs in valleys near the center of the system. Given what seems to be likely rock characteristics and geometries at depth, insufficient water is simulated to reach the discharge areas. This "surprise" thus challenges preconceived notions about the system. Here we use the hydrogeologic model to hypothesize alternatives able to produce the observed flow and use the groundwater simulation to test the hypotheses with other available data. Results suggest that the transmissivity measurements need to be used carefully because wells in this system are never fully penetrating, that multiple alternatives are able to produce the springflow, and that one most likely alternative cannot be identified given available data. Consequences of the alternatives are discussed.
Zhang, Lifang; Dou, Peng; Wang, Wenjing; Zheng, Jiao; Xu, Xinhua
2017-11-01
The novel Sn-Cu nanotubes enveloped in three-dimensional (3D) hierarchical polyaniline (PANI) hydrogel (Sn-Cu/PANI) were successfully prepared as a high performance anode for lithium-ion battery. The binder-free electrode exhibits reversible capacity of 548 mA h g-1 after 500 cycles and admirable rate capacity even up to 5000 mA g-1. The exceptional electrochemical performance of Sn-Cu/PANI hydrogel could be attributed to the unique structure: (1) The inactive Cu matrix in binary Sn-Cu compounds and the tubular construction conduce to relieve the volume swing; The high porosity originated from galvanic replacement reaction accelerates ions transmission, which contributes to rapid charging and discharging. (2) The 3D porous PANI framework offers a continuous electron and lithium ions transport network among the whole electrode; the hierarchical PANI serves as mechanical support to accommodate the stress related to the large volume change of Sn-Cu nanotubes, thus reducing the risk of electrode pulverization.
Yu, Mei; Zhang, Jindan; Li, Songmei; Meng, Yanbing; Liu, Jianhua
2016-03-01
Three-dimensional nitrogen doped holey reduced graphene oxide framework (NHGF) with hierarchical porosity structure was developed as high-performance metal-free counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). With plenty of exposed active sites, efficient electron and ion transport pathways as well as a high surface hydrophilicity, NHGF-CE exhibits good electrocatalytic performances for I- /I3- redox couple and a low charge transfer resistance (Rct). The Rct of NHGF-CE is 1.46 Ω cm2, which is much lower than that of Pt-CE (4.02 Ω cm2). The DSSC with NHGF-CE reaches a power conversion efficiency of 5.56% and a fill factor of 65.5%, while those of the DSSC with Pt-CE are only 5.45% and 62.3%, respectively. The achievement of the highly efficient 3D structure presents a potential way to fabricate low-cost and metal-free counter electrodes with excellent performance.
Wang, Congwei; Zhao, Zheng; Li, Xiaofeng; Yan, Rui; Wang, Jie; Li, Anni; Duan, Xiaoyong; Wang, Junying; Liu, Yong; Wang, Junzhong
2017-11-29
The synthesis of durable and low-cost electrocatalyst is crucial but challenging. Here, we developed a one-pot pyrolysis approach toward the preparation of heteroatom-doped hierarchical porous three-dimensional (3D) graphene frameworks decorated with multilayer graphene shell-coated cobalt oxide nanocrystal. Large literal sheet size of graphene nanomeshes may stimulate rapid thermolysis with cobalt-oleate complex to form Co 3 O 4 nanocrystals and in situ growth of multilayer graphene coating co-doped by boron and nitrogen with controlling heating rate up to 600 °C. This new material worked as superior bifunctional electrocatalyst on oxygen reduction reaction and oxygen evolution reaction to commercial Pt/C with better onset potential/half-wave potentials, larger current density, better stability, and stronger methanol tolerance. The heteroatom co-doping into porous/curved graphene confined nanocrystals in 3D porous walls provided adequate accessibility of created catalytic active sites and ideal mass transport route for the excellent catalytic activity on redox reaction of oxygen. The synthesized material-based Zn-air battery further confirmed its superior electrolytic activity with high specific capacity and smaller overpotential. This one-pot pyrolysis method shows a great potential of scalable synthesis of high-performance practical electrocatalyst for metal-air batteries and fuel cells at a low cost.
Shakhawath Hossain, Md; Bergstrom, D J; Chen, X B
2015-12-01
The in vitro chondrocyte cell culture for cartilage tissue regeneration in a perfusion bioreactor is a complex process. Mathematical modeling and computational simulation can provide important insights into the culture process, which would be helpful for selecting culture conditions to improve the quality of the developed tissue constructs. However, simulation of the cell culture process is a challenging task due to the complicated interaction between the cells and local fluid flow and nutrient transport inside the complex porous scaffolds. In this study, a mathematical model and computational framework has been developed to simulate the three-dimensional (3D) cell growth in a porous scaffold placed inside a bi-directional flow perfusion bioreactor. The model was developed by taking into account the two-way coupling between the cell growth and local flow field and associated glucose concentration, and then used to perform a resolved-scale simulation based on the lattice Boltzmann method (LBM). The simulation predicts the local shear stress, glucose concentration, and 3D cell growth inside the porous scaffold for a period of 30 days of cell culture. The predicted cell growth rate was in good overall agreement with the experimental results available in the literature. This study demonstrates that the bi-directional flow perfusion culture system can enhance the homogeneity of the cell growth inside the scaffold. The model and computational framework developed is capable of providing significant insight into the culture process, thus providing a powerful tool for the design and optimization of the cell culture process. © 2015 Wiley Periodicals, Inc.
Guo, Pei Ying; Ma, De Yun; Guo, Hai Fu
2017-06-01
The 2-methylbiphenyl-4,4'-dicarboxylate (mbpdc 2- ) ligand has versatile coordination modes and can be used to construct multinuclear structures. Despite this, reports of the synthesis of coordination complexes involving this ligand are scarce. The title compound, poly[[triaquadi-μ 3 -hydroxido-hexakis(μ 4 -2-methylbiphenyl-4,4'-dicarboxylato)calcium(II)hexazinc(II)] monohydrate], {[CaZn 6 (C 15 H 10 O 4 ) 6 (OH) 2 (H 2 O) 3 ]·H 2 O} n , has been prepared by the hydrothermal assembly of Zn(NO 3 ) 2 ·6H 2 O, CaCl 2 and 2-methylbiphenyl-4,4'-dicarboxylic acid. Two Zn II atoms adopt a four-coordinated distorted tetrahedral geometry by bonding to three O atoms from three different 2-methylbiphenyl-4,4'-dicarboxylate (mbpdc 2- ) dianionic ligands and one bridging hydroxide O atom. For the remaining Zn II atom, a five-coordinate environment is completed half the time by one carboxylate O atom, and then the same carboxylate O atom and an aqua O atom are present the other half of the time, giving a six-coordinate environment. The Ca II atom is coordinated by six O atoms to give an octahedral coordination geometry. The supramolecular secondary building unit (SBU) is a hamburger-like heptanuclear unit (Zn 6 CaO 30 ) and these units are interconnected through mbpdc 2- carboxylate groups to generate a three-dimensional framework with the pcu topology. The single net leaves voids that are filled by mutual interpenetration of an independent equivalent framework in a twofold interpenetrating architecture. The title compound shows thermal stability up to 673 K. The excitation and luminescence data showed the emission of a bright-blue fluorescence.
Rolland, Joran; Domeisen, Daniela I. V.
2016-04-01
Many geophysical waves in the atmosphere or in the ocean have a three dimensional structure and contain a range of scales. This is for instance the case of planetary waves in the stratosphere connected to baroclinic eddies in the troposphere [1]. In the study of such waves from reanalysis data or output of numerical simulations, Empirical Orthogonal Functions (EOF) obtained as a Proper Orthogonal Decomposition of the data sets have been of great help. However, most of these computations rely on the diagonalisation of space correlation matrices: this means that the considered data set can only have a limited number of gridpoints. The main consequence is that such analyses are often only performed in planes (as function of height and latitude, or longitude and latitude for instance), which makes the educing of the three dimensional structure of the wave quite difficult. In the case of the afore mentionned waves, the matter of the longitudinal dependence or the proper correlation between modes through the tropopause is an open question. An elegant manner to circumvent this problem is to consider the output of the Orthogonal Decomposition as a whole. Indeed, it has been shown that the normalised time series of the amplitude of each EOF, far from just being decorrelated from one another, are actually another set of orthogonal functions. These can actually be computed through the diagonlisation of the time correlation matrix of the data set, just like the EOF were the result of the diagonalisation of the space correlation matrix. The signal is then fully decomposed in the framework of the Bi-Orthogonal Decomposition as the sum of the nth explained variance, time the nth eigenmode of the time correlation times the nth eigenmode of the spacial correlations [2,3]. A practical consequence of this result is that the EOF can be reconstructed from the projection of the dataset onto the eigenmodes of the time correlation matrix in the so-called snapshot method [4]. This is very
Ugale, Bharat; Dhankhar, Sandeep Singh; Nagaraja, C M
2016-10-03
A series of three new isostructural metal-organic frameworks (MOFs) of nickel(II), [{Ni(muco)(bpa)(2H2O)}·2H2O] (1), [{Ni(muco)(bpe)(2H2O)}·2.5H2O] (2), and [{Ni(muco)(azopy)(2H2O)}·2H2O] (3) [where muco = trans,trans-muconate dianion, bpa = 1,2-bis(4-pyridyl)ethane, bpe = 1,2-bis(4-pyridyl)ethylene, and azopy = 4,4'-bis(azobipyridine)], have been synthesized and characterized by single-crystal X-ray diffraction analysis and other physicochemical methods. Compounds 1-3 exhibit an interesting 3-fold-interpenetrated three-dimensional pillar-layered framework structure constituted of 4-coordinating (4-c) Ni(II) nodes with {6(6)}-neb net topology. Remarkably, in spite of 3-fold interpenetration, the structures possess one-dimensional channels with dimensions of ∼8.05 × 5.25 Å(2). Gas (N2, Ar, H2, and CO2) adsorption studies of compounds 2 and 3 revealed selective adsorption properties for CO2 over other gases. In all three structures, the 4-c Ni(II) node has two coordinated H2O molecules that can be reversibly removed by high-temperature treatment to generate a dehydrated framework composed of highly unsaturated, Lewis acidic Ni(II) ions. Further, the activated compounds of 1-3 act as efficient recyclable catalysts for heterogeneous cycloaddition of CO2 with styrene oxide, resulting in cyclic carbonate with high conversion and selectivity. Interestingly, the cycloaddition reactions of CO2 with bulky epoxides show a decrease in the activity with an increase in the alkyl chain length of the substrate due to confinement of the pore size of the MOF. The high catalytic efficiency and size-dependent selectivity for smaller epoxides show the potential utility of 1 as a promising heterogeneous catalyst for the cycloaddition of CO2. Furthermore, the catalyst can be easily separated and reused for several cycles without significant reduction in the catalytic activity as well as structural rigidity. Compounds 1-3 represent rare examples of interpenetrated MOFs exhibiting
Three dimensional system integration
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
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
Helbren, E; Halligan, S; Phillips, P; Boone, D; Fanshawe, T R; Taylor, S A; Manning, D; Gale, A; Altman, D G; Mallett, S
2014-05-01
Eye tracking in three dimensions is novel, but established descriptors derived from two-dimensional (2D) studies are not transferable. We aimed to develop metrics suitable for statistical comparison of eye-tracking data obtained from readers of three-dimensional (3D) "virtual" medical imaging, using CT colonography (CTC) as a typical example. Ten experienced radiologists were eye tracked while observing eight 3D endoluminal CTC videos. Subsequently, we developed metrics that described their visual search patterns based on concepts derived from 2D gaze studies. Statistical methods were developed to allow analysis of the metrics. Eye tracking was possible for all readers. Visual dwell on the moving region of interest (ROI) was defined as pursuit of the moving object across multiple frames. Using this concept of pursuit, five categories of metrics were defined that allowed characterization of reader gaze behaviour. These were time to first pursuit, identification and assessment time, pursuit duration, ROI size and pursuit frequency. Additional subcategories allowed us to further characterize visual search between readers in the test population. We propose metrics for the characterization of visual search of 3D moving medical images. These metrics can be used to compare readers' visual search patterns and provide a reproducible framework for the analysis of gaze tracking in the 3D environment. This article describes a novel set of metrics that can be used to describe gaze behaviour when eye tracking readers during interpretation of 3D medical images. These metrics build on those established for 2D eye tracking and are applicable to increasingly common 3D medical image displays.
Three dimensional Dirac semimetals
Zaheer, Saad
We extend the physics of graphene to three dimensional systems by showing that Dirac points can exist on the Fermi surface of realistic materials in three dimensions. Many of the exotic electronic properties of graphene can be ascribed to the pseudorelativistic behavior of its charge carriers due to two dimensional Dirac points on the Fermi surface. We show that certain nonsymmorphic spacegroups exhibit Dirac points among the irreducible representations of the appropriate little group at high symmetry points on the surface of the Brillouin zone. We provide a list of all Brillouin zone momenta in the 230 spacegroups that can host Dirac points. We describe microscopic considerations necessary to design materials in one of the candidate spacegroups such that the Dirac point appears at the Fermi energy without any additional non-Dirac-like Fermi pockets. We use density functional theory based methods to propose six new Dirac semimetals: BiO 2 and SbO2 in the beta-cristobalite lattice (spacegroup 227), and BiCaSiO4, BiMgSiO4, BiAlInO 4, and BiZnSiO4 in the distorted spinels lattice (spacegroup 74). Additionally we derive effective Dirac Hamiltonians given group representative operators as well as tight binding models incorporating spin-orbit coupling. Finally we study the Fermi surface of zincblende (spacegroup 216) HgTe which is effectively point-like at Gamma in the Brillouin zone and exhibits accidental degeneracies along a threefold rotation axis. Whereas compressive strain gaps the band structure into a topological insulator, tensile strain shifts the accidental degeneracies away from Gamma and enlarges the Fermi surface. States on the Fermi surface exhibit nontrivial spin texture marked by winding of spins around the threefold rotation axis and by spin vortices indicating a change in the winding number. This is confirmed by microscopic calculations performed in tensile strained HgTe and Hg0.5Zn 0.5 Te as well as k.p theory. We conclude with a summary of recent
Three-dimensional dispersion analysis of homogeneous ...
African Journals Online (AJOL)
The problem of wave propagation in an infinite, homogeneous, transversely isotropic thermo elastic polygonal cross-sectional bar immersed in fluid is studied using Fourier expansion collocation method, with in the framework of linearized, three dimensional theory of thermoelasticity. Three displacement potential functions ...
Three-dimensional dispersion analysis of homogeneous ...
African Journals Online (AJOL)
user
bar immersed in fluid is studied using Fourier expansion collocation method, with in the framework of linearized, three dimensional theory of thermoelasticity. ...... Performing the Fourier series expansion as discussed in the previous sections to Eq. (31) along the boundary, the boundary conditions along the surfaces are ...
Abolghasemi, Mir Mahdi; Yousefi, Vahid
2014-06-06
A new solid phase microextraction (SPME) fiber based on high-temperature three dimensionally honeycomb layered double hydroxide (TDH-LDH) material is presented. The fiber coating can be prepared easily, it is mechanically stable and exhibits relatively high thermal stability. This study shows that three dimensionally honeycomb layered double hydroxide generated porous morphology. The TDH-LDH material was tested for the extraction of some phenolic and polycyclic aromatic hydrocarbon compounds from aqueous sample solutions in combination with gas chromatography-mass spectrometry (GC-MS). The TDH-LDH fiber contains polar groups and its efficiency for non-polar polycyclic aromatic hydrocarbon compounds was lower than phenolic compounds. On the other hand, a high tendency towards the adsorption of polar phenolic compounds was observed for the proposed fiber. The effects of the extraction and desorption parameters including extraction temperature, extraction time, ionic strength, stirring rate, pH and desorption temperature and time have been studied. In optimum conditions, the repeatability for one fiber (n=5), expressed as relative standard deviation (R.S.D. %), was between 2.8% and 7.1% for the phenolic compounds. The detection limits for the studied phenolic compounds were between 0.02 and 5.8 ng mL(-1). The developed method offers the advantage of being simple to use, with shorter analysis time, lower cost of equipment, thermal stability of fiber and high relative recovery in comparison to conventional methods of analysis. Copyright © 2014 Elsevier B.V. All rights reserved.
Mendes, Ricardo F; Venkatramaiah, Nutalapati; Tomé, João P C; Almeida Paz, Filipe A
2016-12-01
A new metal-organic framework compound, poly[[μ7-dihydrogen (4,5-di-cyano-1,2-phenyl-ene)diphospho-nato]-(oxonium)caesium], [Cs(C8H4N2O6P2)(H3O)] n (I), based on Cs(+) and the organic linker 4,5-di-cyano-1,2-phenyl-ene)bis-(phospho-nic acid, (H4cpp), containing two distinct coordinating functional groups, has been prepared by a simple diffusion method and its crystal structure is reported. The coordination polymeric structure is based on a CsO8N2 complex unit comprising a monodentate hydro-nium cation, seven O-atom donors from two phospho-nium groups of the (H2cpp)(2-) ligand, and two N-atom donors from bridging cyano groups. The high level of connectivity from both the metal cation and the organic linker allow the formation of a compact and dense three-dimensional network without any crystallization solvent. Topologically (I) is a seven-connected uninodal network with an overall Schäfli symbol of {4(17).6(4)}. Metal cations form an undulating inorganic layer, which is linked by strong and highly directional O-H⋯O hydrogen-bonding inter-actions. These metallic layers are, in turn, connected by the organic ligands along the [010] direction to form the overall three-dimensional framework structure.
Directory of Open Access Journals (Sweden)
E. Roccatello
2013-05-01
This work could be seen as an extension of the Cityvu project, started in 2008 with the aim of a plug-in free OGC CityGML viewer. The resulting framework has also been integrated in existing 3DGIS software products and will be made available in the next months.
Mei, Lei; Xie, Zhen-Ni; Hu, Kong-Qiu; Wang, Lin; Yuan, Li-Yong; Li, Zi-Jie; Chai, Zhi-Fang; Shi, Wei-Qun
2016-09-14
The first 3D actinide polyrotaxane framework (named IHEP-URCP-2) has been obtained based on windmill-like six-connected high-nuclear oligomeric uranyl nodes under hydrothermal conditions. Notably, the in situ formed pseudorotaxane ligand simultaneously plays dual roles of both a bulky pseudorotaxane linker and a supramolecular guest.
Roccatello, E.; Nozzi, A.; Rumor, M.
2013-05-01
This paper illustrates the key concepts behind the design and the development of a framework, based on OGC services, capable to visualize 3D large scale geospatial data streamed over the web. WebGISes are traditionally bounded to a bi-dimensional simplified representation of the reality and though they are successfully addressing the lack of flexibility and simplicity of traditional desktop clients, a lot of effort is still needed to reach desktop GIS features, like 3D visualization. The motivations behind this work lay in the widespread availability of OGC Web Services inside government organizations and in the technology support to HTML 5 and WebGL standard of the web browsers. This delivers an improved user experience, similar to desktop applications, therefore allowing to augment traditional WebGIS features with a 3D visualization framework. This work could be seen as an extension of the Cityvu project, started in 2008 with the aim of a plug-in free OGC CityGML viewer. The resulting framework has also been integrated in existing 3DGIS software products and will be made available in the next months.
Three-dimensional stellarator codes.
Garabedian, P R
2002-08-06
Three-dimensional computer codes have been used to develop quasisymmetric stellarators with modular coils that are promising candidates for a magnetic fusion reactor. The mathematics of plasma confinement raises serious questions about the numerical calculations. Convergence studies have been performed to assess the best configurations. Comparisons with recent data from large stellarator experiments serve to validate the theory.
Three-dimensional stellarator codes
Garabedian, P. R.
2002-01-01
Three-dimensional computer codes have been used to develop quasisymmetric stellarators with modular coils that are promising candidates for a magnetic fusion reactor. The mathematics of plasma confinement raises serious questions about the numerical calculations. Convergence studies have been performed to assess the best configurations. Comparisons with recent data from large stellarator experiments serve to validate the theory. PMID:12140367
Directory of Open Access Journals (Sweden)
Akimov Pavel Alekseevich
2012-10-01
Full Text Available The proposed paper covers the operator-related formulation of the eigenvalue problem of analysis of a three-dimensional structure that has piecewise-constant physical and geometrical parameters alongside the so-called basic direction within the framework of a discrete-continual approach (a discrete-continual finite element method, a discrete-continual variation method. Generally, discrete-continual formulations represent contemporary mathematical models that become available for computer implementation. They make it possible for a researcher to consider the boundary effects whenever particular components of the solution represent rapidly varying functions. Another feature of discrete-continual methods is the absence of any limitations imposed on lengths of structures. The three-dimensional problem of elasticity is used as the design model of a structure. In accordance with the so-called method of extended domain, the domain in question is embordered by an extended one of an arbitrary shape. At the stage of numerical implementation, relative key features of discrete-continual methods include convenient mathematical formulas, effective computational patterns and algorithms, simple data processing, etc. The authors present their formulation of the problem in question for an isotropic medium with allowance for supports restrained by elastic elements while standard boundary conditions are also taken into consideration.
DEFF Research Database (Denmark)
Deng, Xiaoyang; Li, Jiajun; Zhu, Shan
2017-01-01
The honeycomb-like porous Co3O4 grown on three dimensional graphene networks/nickel foam (3DGN/NF) has been successfully prepared by a facile solution growth process with subsequent annealing treatment, in which the Co-based metal organic framework (ZIF-67) act as the precursor of the metal oxide....... The Co3O4/three-dimensional graphene networks/Ni foam (Co3O4/3DGN/NF) hybrid as the electrode for supercapacitor can deliver high specific capacitance (321 F g−1 at 1 A g−1) and excellent long-cycling stability (88% of the maximum capacitance after 2000 charge-discharge cycles). Furthermore, the Co3O4...... pseudocapacitance performance and the intimate integration of graphene with the Co3O4 and the Ni foam matrix, which not only enhances the electron conductivity for fast electron and ion transport but also provides high specific surface area and excellent structural stability....
Lee, Ki-Sun; Shin, Sang-Wan; Lee, Sang-Pyo; Kim, Jong-Eun; Kim, Jee-Hwan; Lee, Jeong-Yol
The purpose of this pilot study was to evaluate and compare polyetherketoneketone (PEKK) with different framework materials for implant-supported prostheses by means of a three-dimensional finite element analysis (3D-FEA) based on cone beam computed tomography (CBCT) and computer-aided design (CAD) data. A geometric model that consisted of four maxillary implants supporting a prosthesis framework was constructed from CBCT and CAD data of a treated patient. Three different materials (zirconia, titanium, and PEKK) were selected, and their material properties were simulated using FEA software in the generated geometric model. In the PEKK framework (ie, low elastic modulus) group, the stress transferred to the implant and simulated adjacent tissue was reduced when compressive stress was dominant, but increased when tensile stress was dominant. This study suggests that the shock-absorbing effects of a resilient implant-supported framework are limited in some areas and that rigid framework material shows a favorable stress distribution and safety of overall components of the prosthesis.
Zhao, Xinyu; Liang, Dadong; Liu, Shuxia; Sun, Chunyan; Cao, Ruige; Gao, Chaoying; Ren, Yuanhang; Su, Zhongmin
2008-08-18
The Dawson anion P 2W 18O 62 (6-) has been used as a noncoordinating polyoxoanion template for the construction of two metal-organic frameworks, namely, [M 2(bpy) 3(H 2O) 2(ox)][P 2W 18O 62]2(H 2-bpy). nH 2O (M = Co(II), n = 3 ( 1); M = Ni(II), n = 2 ( 2)) (bpy = 4,4'-bipyridine; ox = C 2O 4 (2-)). Single-crystal X-ray analysis reveals that both of the structures exhibit 3D host frameworks constructed from the oxalate-bridged binuclear superoctahedron secondary building units (SBUs) and bpy linkers and the voids of which are occupied by Dawson anions, guest bpy, and water molecules. Magnetic studies reveal that there are antiferromagnetic exchange interactions among the transition-metal centers in compounds 1 and 2. Furthermore, a compound 1-modified carbon paste electrode ( 1-CPE) displays good electrocatalytic activity toward the reduction of nitrite.
Datcu, Angela; Roques, Nans; Jubera, Véronique; Imaz, Inhar; Maspoch, Daniel; Sutter, Jean-Pascal; Rovira, Concepció; Veciana, Jaume
2011-03-21
A series of isostructural open-framework coordination polymers formulated as [Ln(dmf)(3)(ptmtc)] (Ln = Sm (1), Eu (2), Gd (3), Tb (4), Dy (5); PTMTC = polychlorotriphenylmethyl tricarboxylate) and [Ln(dmf)(2)H(2)O(αH-ptmtc)] (Ln = Sm (1'), Eu (2'), Gd (3'), Tb (4'), Dy (5')) have been obtained by treating Ln(III) ions with PTMTC ligands with a radical (PTMTC(3-)) or a closed-shell character (αH-PTMTC(3-)). X-ray diffraction analyses reveal that these coordination polymers possess 3D architectures that combine large channels and fairly rare lattice complex T connectivity. In addition, these compounds show selective framework dynamic sorption properties. For both classes of ligands, the ability to act as an antenna in Ln sensitization processes has been investigated. No luminescence was observed for compounds 1-5, and 3' because of the PTMTC(3-) ligand and/or Gd(III) ion characteristics. Conversely, photoluminescence measurements show that 1', 2', 4', and 5' emit dark orange, red, green, and dark cyan metal-centered luminescence. The magnetic properties of all of these compounds have been investigated. The nature of the {Ln-radical} exchange interaction in these compounds has been assessed by comparing the behavior of the radical-based coordination polymers 1-5 with those of the compounds with the diamagnetic ligand set. While antiferromagnetic {Sm-radical} interactions are found in 1, ferromagnetic {Ln-radical} interactions propagate in the 3D architectures of 3, 4, and 5 (Ln = Gd, Tb, and Dy, respectively). This procedure also provided access to information on the {Ln-Ln} exchange existing in these magnetic systems. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Kido, Kentaro; Kasahara, Kento; Yokogawa, Daisuke; Sato, Hirofumi
2015-07-07
In this study, we reported the development of a new quantum mechanics/molecular mechanics (QM/MM)-type framework to describe chemical processes in solution by combining standard molecular-orbital calculations with a three-dimensional formalism of integral equation theory for molecular liquids (multi-center molecular Ornstein-Zernike (MC-MOZ) method). The theoretical procedure is very similar to the 3D-reference interaction site model self-consistent field (RISM-SCF) approach. Since the MC-MOZ method is highly parallelized for computation, the present approach has the potential to be one of the most efficient procedures to treat chemical processes in solution. Benchmark tests to check the validity of this approach were performed for two solute (solute water and formaldehyde) systems and a simple SN2 reaction (Cl(-) + CH3Cl → ClCH3 + Cl(-)) in aqueous solution. The results for solute molecular properties and solvation structures obtained by the present approach were in reasonable agreement with those obtained by other hybrid frameworks and experiments. In particular, the results of the proposed approach are in excellent agreements with those of 3D-RISM-SCF.
Liang, Feng Lan; Ma, De Yun; Qin, Liang
2016-05-01
Metal-organic frameworks (MOFs) are a new class of porous materials that have received widespread attention due to their potential applications in gas storage and/or separation, catalysis, luminescence, and so on. The title compound, poly[[(μ2-3,3'-dimethyl-4,4'-bipyridine-κ(2)N:N')bis(μ4-4,4'-oxydibenzoato-κ(4)O:O':O'':O''')dizinc] tetrahydrate], {[Zn2(C14H8O5)2(C12H12N2)]·4H2O}n, has been prepared by the solvothermal assembly of Zn(NO3)2·6H2O, 4,4'-oxydi(benzoic acid) and 3,3'-dimethyl-4,4'-bipyridine. The two Zn(II) atoms adopt the same five-coordinated distorted square-pyramidal geometry (i.e. ZnO4N), bonding to four O atoms from four different 4,4'-oxydibenzoate (oba) ligands and one N atom from a 3,3'-dimethyl-4,4'-bipyridine (dmbpy) ligand. The supramolecular secondary building unit (SBU) is a paddle-wheel [Zn2(COO)4] unit and these units are linked by oba ligands within the layer to form a two-dimensional net parallel to the b axis, with the dmbpy ligands pointing alternately up and down, which is further extended by dmbpy ligands to form a three-dimensional framework with rob topology. The single net leaves voids that are filled by mutual interpenetration of an independent equivalent framework in a twofold interpenetrating architecture. The title compound shows thermal stability up to 673 K and is stable in aqueous solutions in the pH range 5-9. Excitation and luminescence data observed at room temperature show that it emits a bright-blue fluorescence.
Three dimensional analysis of natural
Directory of Open Access Journals (Sweden)
Lioua Kolsi
2016-06-01
Full Text Available A computational study has been performed to make a computational analysis of natural convection and entropy generation in a sharp edged finned cavity. Three dimensional analysis has been done by solving governing equations with a written computational code in Fortran. The study is performed for fin inclination angles from −60° to 60°, Ra = 105, Pr = 0.7, Rc (conductivities ratio changes from 0.01 to 100 and irreversibility coefficient is taken as φ=10-5. It is observed that higher values of thermal conductivity ratio (Rc ⩾ 1 do not affect entropy generation due to heat transfer and Bejan number.
Three-dimensional spheromak merging
Oda, Y.; Sato, T.
1983-04-01
Spheromak is an attractive object both technically and physically to nuclear fusion plasma research. Because of the compactness and versatility coming from its intrinsic nature that the confinement magnetic fields are topologically separated from the external circuit, there are several technical advantages in designing a fusion reactor. Spheromak provides several physically interesting subjects, particularly as an object for revealing global plasma dynamics. For example, it is interesting to know how such a self-confined plasma is created starting from a realistic condition. It is interesting also to know whether such a self-confined plasma is configurationally stable or unstable and, if unstable, by what dynamics the evolution is governed. Three-dimensional simulations have disclosed that the plasma suffers a tilting disruption through reconnection and recent more extensive 3-D simulations have examined in detail the global dynamics of tilting instability and the remedies of the instability.
Yang, Shui-Ping; Chen, Shao-Rui; Liu, Shu-Wen; Tang, Xiao-Yan; Qin, Liang; Qiu, Gui-Hua; Chen, Jin-Xiang; Chen, Wen-Hua
2015-12-15
We herein report a water-stable three-dimensional Cu-based metal-organic framework (MOF) 1 supported by a tritopic quaternized carboxylate and 4,4'-dipyridyl sulfide as an ancillary ligand. This MOF exhibits unique pore shapes with aromatic rings, positively charged pyridinium and unsaturated Cu(II) cation centers, free carboxylates, tessellating H2O, and coordinating SO4(2-) on the pore surface. Compound 1 can interact with two carboxyfluorescein (FAM)-labeled single-stranded DNA sequences (probe ss-DNA, delineated as P-DNA) through electrostatic, π-stacking, and/or hydrogen-bonding interactions to form two P-DNA@1 systems, and thus quench the fluorescence of FAM via a photoinduced electron-transfer process. These P-DNA@1 systems can be used as effective fluorescent sensors for human immunodeficiency virus 1 double-stranded DNA and Sudan virus RNA sequences, respectively, with detection limits of 196 and 73 pM, respectively.
Three-Dimensional Laser Microvision
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.
Three-dimensional fetal cephalometry.
Bettega, G; Chenin, M; Sadek, H; Cinquin, P; Lebeau, J; Coulomb, M; Raphaël, B
1996-11-01
Craniofacial growth has been the subject of numerous studies in which different techniques have been elaborated aiming to model this dynamic phenomenon in a rational manner. One of the methods employed is cephalometric analysis applied to the fetus. Generally, however, these studies are confined to the exploration of a single spatial plane (sagittal plane), whose orientation is never defined in a rigorous and perfectly reproducible manner. Thus, none of these analyses offers a formal growth model. This has led us to propose a new method of fetal cephalometric study taking into account criteria for proper reproducible analysis: spatial exploration of the head performed through three-dimensional tomodensitometric images and precise location of landmarks and reproducibility of the orientation of each image, which is assured by reference to the vestibular orientation (based on the external semicircular canals), as has been described by Girard and Perez and further developed by Fenart. When the labyrinth is developed, this orientation does not change during the growth stages of the head, even with craniofacial deformities. This permits application of this orientation on fetuses and the superposition of images of different subjects. The methodology is presented using two normal human fetuses, and the advantages of this computerized tool are discussed.
Three-dimensional display technologies
Geng, Jason
2014-01-01
The physical world around us is three-dimensional (3D), yet traditional display devices can show only two-dimensional (2D) flat images that lack depth (i.e., the third dimension) information. This fundamental restriction greatly limits our ability to perceive and to understand the complexity of real-world objects. Nearly 50% of the capability of the human brain is devoted to processing visual information [Human Anatomy & Physiology (Pearson, 2012)]. Flat images and 2D displays do not harness the brain’s power effectively. With rapid advances in the electronics, optics, laser, and photonics fields, true 3D display technologies are making their way into the marketplace. 3D movies, 3D TV, 3D mobile devices, and 3D games have increasingly demanded true 3D display with no eyeglasses (autostereoscopic). Therefore, it would be very beneficial to readers of this journal to have a systematic review of state-of-the-art 3D display technologies. PMID:25530827
Three dimensional magnetic abacus memory.
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.
Exact solutions in three-dimensional gravity
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...
Three-dimensional coupled double-distribution-function lattice ...
Indian Academy of Sciences (India)
Two three-dimensional (3D) lattice Boltzmann models in the framework of coupled double-distribution function approach for compressible flows, in which specific-heat ratio and Prandtl number can be adjustable, aredeveloped in this paper. The main differences between the two models are discrete equilibrium density and ...
Oblique water entry of a three dimensional body
Directory of Open Access Journals (Sweden)
Scolan Yves-Marie
2014-12-01
Full Text Available The problem of the oblique water entry of a three dimensional body is considered. Wagner theory is the theoretical framework. Applications are discussed for an elliptic paraboloid entering an initially flat free surface. A dedicated experimental campaign yields a data base for comparisons. In the present analysis, pressure, force and dynamics of the wetted surface expansion are assessed.
Elastocapillary fabrication of three-dimensional microstructures
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
Computational methods for three-dimensional microscopy reconstruction
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.
Three-dimensional images of choanoflagellate loricae
Leadbeater, Barry S.C; Yu, QiBin; Kent, Joyce; Stekel, Dov J
2008-01-01
Choanoflagellates are unicellular filter-feeding protozoa distributed universally in aquatic habitats. Cells are ovoid in shape with a single anterior flagellum encircled by a funnel-shaped collar of microvilli. Movement of the flagellum creates water currents from which food particles are entrapped on the outer surface of the collar and ingested by pseudopodia. One group of marine choanoflagellates has evolved an elaborate basket-like exoskeleton, the lorica, comprising two layers of siliceous costae made up of costal strips. A computer graphic model has been developed for generating three-dimensional images of choanoflagellate loricae based on a universal set of ‘rules’ derived from electron microscopical observations. This model has proved seminal in understanding how complex costal patterns can be assembled in a single continuous movement. The lorica, which provides a rigid framework around the cell, is multifunctional. It resists the locomotory forces generated by flagellar movement, directs and enhances water flow over the collar and, for planktonic species, contributes towards maintaining cells in suspension. Since the functional morphology of choanoflagellate cells is so effective and has been highly conserved within the group, the ecological and evolutionary radiation of choanoflagellates is almost entirely dependent on the ability of the external coverings, particularly the lorica, to diversify. PMID:18755674
Automatic creation of three-dimensional avatars
Villa-Uriol, Maria-Cruz; Sainz, Miguel; Kuester, Falko; Bagherzadeh, Nader
2003-01-01
Highly accurate avatars of humans promise a new level of realism in engineering and entertainment applications, including areas such as computer animated movies, computer game development interactive virtual environments and tele-presence. In order to provide high-quality avatars, new techniques for the automatic acquisition and creation are required. A framework for the capture and construction of arbitrary avatars from image data is presented in this paper. Avatars are automatically reconstructed from multiple static images of a human subject by utilizing image information to reshape a synthetic three-dimensional articulated reference model. A pipeline is presented that combines a set of hardware-accelerated stages into one seamless system. Primary stages in this pipeline include pose estimation, skeleton fitting, body part segmentation, geometry construction and coloring, leading to avatars that can be animated and included into interactive environments. The presented system removes traditional constraints in the initial pose of the captured subject by using silhouette-based modification techniques in combination with a reference model. Results can be obtained in near-real time with very limited user intervention.
Three Dimensional Optic Tissue Culture and Process
OConnor, Kim C. (Inventor); Spaulding, Glenn F. (Inventor); Goodwin, Thomas J. (Inventor); Aten, Laurie A. (Inventor); Francis, Karen M. (Inventor); Caldwell, Delmar R. (Inventor); Prewett, Tacey L. (Inventor); Fitzgerald, Wendy S. (Inventor)
1999-01-01
A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioireactor at low shear conditions. The tissue forms as normal, functional tissue grows with tissue organization and extracellular matrix formation.
Three-dimensional imaging modalities in endodontics
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 visualize...
PLANAR SECTIONS THROUGH THREE-DIMENSIONAL LINE-SEGMENT PROCESSES
Directory of Open Access Journals (Sweden)
Sascha Djamal Matthes
2014-03-01
Full Text Available This paper studies three-dimensional segment processes in the framework of stochastic geometry. The main objective is to find relations between the characteristics of segment processes such as orientation- and length-distribution, and characteristics of their sections with planes. Formulae are derived for the distribution of segment lengths on both sides of the section plane and corresponding orientations, where it is permitted that there are correlations between the angles and lengths of the line-segments.
Three-Dimensional Shallow Water Acoustics
2016-03-30
13-1-0026 entitled "Three- Dimensional Shallow Water Acoustics ," Principal Investigator Dr. Ying-Tsong Lin. Sincerely, ;l1,J-Ju1 ~{hjM1...30/03/2016 01/01/2013-12/31/2015 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBERS Three-Dimensional Shallow Water Acoustics 5b, GRANT NUMBER N0001 4-13-1...effects. The long-term goals of this project are targeted on understanding the 3-D acoustic effects, and their temporal and spatial variability, caused
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......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...
Three-dimensional displays and stereo vision.
Westheimer, Gerald
2011-08-07
Procedures for three-dimensional image reconstruction that are based on the optical and neural apparatus of human stereoscopic vision have to be designed to work in conjunction with it. The principal methods of implementing stereo displays are described. Properties of the human visual system are outlined as they relate to depth discrimination capabilities and achieving optimal performance in stereo tasks. The concept of depth rendition is introduced to define the change in the parameters of three-dimensional configurations for cases in which the physical disposition of the stereo camera with respect to the viewed object differs from that of the observer's eyes.
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 of a c...
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 ...
Three-Dimensional Messages for Interstellar Communication
Vakoch, Douglas A.
One of the challenges facing independently evolved civilizations separated by interstellar distances is to communicate information unique to one civilization. One commonly proposed solution is to begin with two-dimensional pictorial representations of mathematical concepts and physical objects, in the hope that this will provide a foundation for overcoming linguistic barriers. However, significant aspects of such representations are highly conventional, and may not be readily intelligible to a civilization with different conventions. The process of teaching conventions of representation may be facilitated by the use of three-dimensional representations redundantly encoded in multiple formats (e.g., as both vectors and as rasters). After having illustrated specific conventions for representing mathematical objects in a three-dimensional space, this method can be used to describe a physical environment shared by transmitter and receiver: a three-dimensional space defined by the transmitter--receiver axis, and containing stars within that space. This method can be extended to show three-dimensional representations varying over time. Having clarified conventions for representing objects potentially familiar to both sender and receiver, novel objects can subsequently be depicted. This is illustrated through sequences showing interactions between human beings, which provide information about human behavior and personality. Extensions of this method may allow the communication of such culture-specific features as aesthetic judgments and religious beliefs. Limitations of this approach will be noted, with specific reference to ETI who are not primarily visual.
Fluorescence confocal polarizing microscopy: Three-dimensional ...
Indian Academy of Sciences (India)
Three-dimensional imaging of the director. O D LAVRENTOVICH. Chemical Physics ... cholesteric LCs. Keywords. 3D imaging; confocal microscopy; liquid crystals; dislocations. PACS Nos 07.60. ... magnetic resonance, x-ray diffraction, optical phase retardation, etc., suffer from the same deficiency: they produce only an ...
Electron crystallography of three dimensional protein crystals
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
Imaging unsteady three-dimensional transport phenomena
Indian Academy of Sciences (India)
2014-01-05
Jan 5, 2014 ... interferometry, schlieren imaging, and shadowgraph. Images recorded in these configurations can be analysed to yield time sequences of three-dimensional distributions of the transported variables. Optical methods are non-intrusive, inertia-free and can image cross-sections of the experimental apparatus.
Three dimensional conformal postoperative radiotherapy for ...
African Journals Online (AJOL)
Azza Helal
2013-06-17
Jun 17, 2013 ... Abbreviations: 3DCRT, three dimensional conformal radiotherapy;. OARs, organs at risk; DVPs, dose volume parameters; PTV, planning target volume; RT, radiation therapy; ACOD, Alexandria Clinical. Oncology Department; CT, computed tomography; ICRU, Interna- tional Commission on Radiation Units; ...
Three-dimensional carpal kinematics in vivo
Moojen, T. M.; Snel, J. G.; Ritt, M. J. P. F.; Kauer, J. M. G.; Venema, H. W.; Bos, K. E.
2002-01-01
Objective. The purpose of this study was to accurately quantify three-dimensional in vivo kinematics of all carpal bones in flexion and extension and radial and ulnar deviation. Design and methods. The right wrists of 11 healthy volunteers were imaged by spiral CT with rotational increments of
Uncalibrated Three-Dimensional Microrobot Control
2016-05-11
R. Nelson, "Experimental evaluation of uncalibrated visual servoing for precision manipulation ," in IEEE Int. Conf. on Robotics and Automation, 1997...distribution is UNLIMITED. 13. SUPPLEMENTARY NOTES 14. ABSTRACT The emerging field of microrobotics facilitates precise manipulation of...magnetic actuation and visual sensor system for a microrobot in a three-dimensional fluidic environment, and then on the development of an
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...
Directory of Open Access Journals (Sweden)
Sami Saraperä
2004-01-01
Full Text Available Elevated concentrations of sulphate, chloride, and nickel were discovered in water samples taken from the Töllinperä aquifer in western Finland. The area is located adjacent to the tailings area of the Hitura nickel mine. Earlier studies revealed that the groundwater contamination resulted from tailings-derived mine waters leaking from a tailings impoundment area. The tailings area directly overlies the Weichselian esker system, part of which is the Töllinperä classified groundwater area. The observed groundwater and surface water contamination resulted in a need to characterize the subsurface geology in the whole area of the contaminated esker aquifer. The primary sedimentary units were introduced into a three-dimensional (3-D geologic model of the aquifer made with EarthVision geologic modeling software. The information obtained from the 3-D geological model was then introduced into a numerical groundwater flow model made with MODFLOW code, which was calibrated with MODFLOWP code.The results of this study were used to guide the sealing of the tailings impoundment in order to prevent the further contamination of the Töllinperä aquifer. The groundwater flow model was used to interpret and simulate the flow system, and to provide a plan to safely continue water supply to local inhabitants from the unpolluted parts of the aquifer.
Li, Qiang; Wang, Hui-Ting; Zhou, Lin
2015-02-01
A new tetrazole-metal supramolecular compound, di-μ-chlorido-bis(trichlorido{1-[(1H-tetrazol-5-yl-κN(2))methyl]-1,4-diazoniabicyclo[2.2.2]octane}cadmium(II)), [Cd2(C8H16N6)2Cl8], has been synthesized and structurally characterized by single-crystal X-ray diffraction. In the structure, each Cd(II) cation is coordinated by five Cl atoms (two bridging and three terminal) and by one N atom from the 1-[(1H-tetrazol-5-yl)methyl]-1,4-diazoniabicyclo[2.2.2]octane ligand, adopting a slightly distorted octahedral coordination geometry. The bridging bicyclo[2.2.2]octane and chloride ligands link the Cd(II) cations into one-dimensional ribbon-like N-H...Cl hydrogen-bonded chains along the b axis. An extensive hydrogen-bonding network formed by N-H...Cl and C-H...Cl hydrogen bonds, and interchain π-π stacking interactions between adjacent tetrazole rings, consolidate the crystal packing, linking the poymeric chains into a three-dimensional supramolecular network.
López Garzón, Rafael; López León, M Dolores; Low, John N; Glidewell, Christopher
2005-05-01
In the title complex, [Ba(C10H12N5O6)2(H2O)6]n, the Ba atom is nine-coordinated by six water ligands and three carboxylate O atoms. The Ba2+ cations and the anionic glutamate ligands form coordination polymer chains, and these chains are linked by pairs of N-H...O hydrogen bonds and pairs of O-H...O hydrogen bonds to form a continuous three-dimensional framework of cations and anions, which is reinforced by hydrogen bonds involving the water molecules.
Three-dimensional calculation and visualization of fault gouge ratio
Energy Technology Data Exchange (ETDEWEB)
Hoffman, Karen S.; Neave, John W. [Dynamic Graphics, Inc., Alameda, CA (United States)
2000-07-01
Understanding the sealing characteristics of faults is critical in assessing the hydrocarbon potential of traps formed by faults. Fault gouge ratio and juxtaposition analysis have often been limited to a single cross section (a two-dimensional approach) or to a single, isolated fault surface (a partial three-dimensional approach). We have now developed a full three-dimensional solution for calculating fault gouge ratio. This method uses a continually varying clay volume fraction, a network of faults (isolated, dying and/or branching), and displacement along the fault surface (instead of just the dip component). The structural model used as the framework for this calculation is based on geometric reconstruction techniques that construct faults and horizons in three-dimensional space, allowing easy and rigorous calculation of juxtaposition and displacement. These last two items are necessary input to the fault gouge ratio calculation. Rigorous calculation of fault gouge ratio depends on a robust structural model. With the model described herein, a variety of scenarios may be investigated, thus incorporating uncertainty into the calculation. Determining whether a fault will act as a seal, or whether there is potential for development of leaks during the production of the reservoir depends on many variables. Minimizing the uncertainty in this analysis may provide increased confidence in assessing risk. (author)
Three-dimensional Imaging, Visualization, and Display
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...
[Three dimensional stereotactic functional neurosurgical planning].
Ochiai, Taku; Regis, Jean; Hayashi, Motohiro; Bartolomei, Fabrice; Hori, Tomokatsu
2004-04-01
In order to arrive the small area in the deep brain with minimum invasion, stereotactic technique is useful. Subthalamic nucleus stimulation with this technique has been common for Parkinson disease. Recently some papers reported the cognitive performance change after implantation and there were some discussion about the electrode trajectory. Though we didn't have the answer until now, three-dimensional target included the trajectory seems to be important. Another way, stereotactic technique was used the epilepsy evaluation. The point of this procedure was based on the clinical aspect, the well-known neural network and the anatomical understanding for each patient. Three-dimensional anatomical target provides us the best treatment for stereotactic neurosurgery.
Arching in three-dimensional clogging
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.
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.
Three-dimensional imaging modalities in endodontics.
Mao, Teresa; Neelakantan, Prasanna
2014-09-01
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.
Three-dimensional accelerating electromagnetic waves.
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.
Flexible three-dimensional printed antenna substrates
Directory of Open Access Journals (Sweden)
Syed Sheheryar Bukhari
2015-08-01
Full Text Available Flexible heterogeneous substrates have been constructed, using three-dimensional printing in a single process, by introducing air-filled slots. These substrates have been used to substantially reduce the substrate losses for a flexible microstrip patch antenna causing an increase in its radiation efficiency. By combining transverse magnetic (TM10 and TM01 modes the bandwidth of this antenna has also been increased.
Three-dimensional printing of biological matters
Munaz, Ahmed; Raja K. Vadivelu; St John, James; Barton, Matthew; Kamble, Harshad; Nguyen, Nam-Trung
2016-01-01
Three-dimensional (3D) printing of human tissues and organ has been an exciting research topic in the past three decades. However, existing technological and biological challenges still require a significant amount of research. The present review highlights these challenges and discusses their potential solutions such as mapping and converting a human organ onto a 3D virtual design, synchronizing the virtual design with the printing hardware. Moreover, the paper discusses in details recent ad...
Visualization of three-dimensional CFD solutions
Modiano, David L.; Giles, Michael B.; Murman, Earll M.
1989-01-01
The implementation is described of the FLOWVIS flow visualization package on a graphics supercomputer that provides real-time interactive investigation of three-dimensional CFD solutions on structured and unstructured meshes. The data structures are briefly described and the methods of visualizing flow fields are examined, including surface plots, particle paths, and planar displays in the flow field. Preliminary results using the package and work in progress are discussed.
Visualization of three-dimensional CFD solutions
Energy Technology Data Exchange (ETDEWEB)
Modiano, D.L.; Giles, M.B.; Murman, E.M.
1989-01-01
The implementation is described of the FLOWVIS flow visualization package on a graphics supercomputer that provides real-time interactive investigation of three-dimensional CFD solutions on structured and unstructured meshes. The data structures are briefly described and the methods of visualizing flow fields are examined, including surface plots, particle paths, and planar displays in the flow field. Preliminary results using the package and work in progress are discussed. 9 references.
Multiparallel Three-Dimensional Optical Microscopy
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.
Three-Dimensional Imaging. Chapter 10
Kelso, R. M.; Delo, C.
1999-01-01
This chapter is concerned with three-dimensional imaging of fluid flows. Although relatively young, this field of research has already yielded an enormous range of techniques. These vary widely in cost and complexity, with the cheapest light sheet systems being within the budgets of most laboratories, and the most expensive Magnetic Resonance Imaging systems available to a select few. Taking the view that the most likely systems to be developed are those using light sheets, the authors will relate their knowledge and experience of such systems. Other systems will be described briefly and references provided. Flows are inherently three-dimensional in structure; even those generated around nominally 2-D surface geometry. It is becoming increasingly apparent to scientists and engineers that the three-dimensionalities, both large and small scale, are important in terms of overall flow structure and species, momentum, and energy transport. Furthermore, we are accustomed to seeing the world in three dimensions, so it is natural that we should wish to view, measure and interpret flows in three-dimensions. Unfortunately, 3-D images do not lend themselves to convenient presentation on the printed page, and this task is one of the challenges facing us.
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.).
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.
Three-dimensionally layered ceramic blocks.
Kurbad, Andreas
2010-01-01
With the aid of an innovatively structured ceramic block, it is possible to achieve results at a high esthetic level with relatively simple means. In the three-dimensionally structured Vitablocs RealLife, translucent enamel ceramic is arranged around a conically structured, opaque dentin core. The virtual restoration can be positioned freely in all three dimensions with the aid of the Cerec/inLab software. The restorations are milled fully anatomically and only minimally glazed or characterized with stains. Results that otherwise can be achieved only with much more complex layering processes are possible.
Three-dimensional flow about penguin wings
Noca, Flavio; Sudki, Bassem; Lauria, Michel
2012-11-01
Penguins, contrary to airborne birds, do not need to compensate for gravity. Yet, the kinematics of their wings is highly three-dimensional and seems exceedingly complex for plain swimming. Is such kinematics the result of an evolutionary optimization or is it just a forced adaptation of an airborne flying apparatus to underwater swimming? Some answers will be provided based on flow dynamics around robotic penguin wings. Updates will also be presented on the development of a novel robotic arm intended to simulate penguin swimming and enable novel propulsion devices.
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...
Sweeping of three-dimensional objects
Martin, Ralph Robert; Stephenson, P. C.
1990-01-01
Evaluating the volume swept out by a three-dimensional (3D) object as it moves along an arbitrary path is of interest to many areas of CAD and CAM, such as mechanism design and robot path planning. This paper shows how envelope theory from differential geometry can be used to find the volumes swept out by the individual surfaces of a solid body, and how computer algebra methods may be of use to perform the computations involved. Finally, a new algorithm is presented which shows how the result...
Three-Dimensional Printing in Orthopedic Surgery.
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.
Zhao, Jun-Wei; Jia, Hong-Peng; Zhang, Jie; Zheng, Shou-Tian; Yang, Guo-Yu
2007-01-01
The hydrothermal reactions of trivacant Keggin A-alpha-XW(9)O(34) polyoxoanions (X=P(V)/Si(IV)) with transition-metal ions (Ni(II)/Cu(II)/Fe(II)) in the presence of amines result in eight novel high-nuclear transition-metal-substituted polyoxotungstates [{Ni(7)(mu(3)-OH)(3)O(2)(dap)(3)(H(2)O)(6)}(B-alpha-PW(9)O(34))][{Ni(6)(mu(3)-OH)(3)(dap)(3)(H(2)O)(6)}(B-alpha-PW(9)O(34))][Ni(dap)(2)(H(2)O)(2)]4.5 H(2)O (1), [Cu(dap)(H(2)O)(3)](2)[{Cu(8)(dap)(4)(H(2)O)(2)}(B-alpha-SiW(9)O(34))(2)]6 H(2)O (2), (enH(2))(3)H(15)[{Fe(II) (1.5)Fe(III) (12)(mu(3)-OH)(12)(mu(4)-PO(4))(4)}(B-alpha-PW(9)O(34))(4)]ca.130 H(2)O (3), [{Cu(6)(mu(3)-OH)(3)(en)(3) (H(2)O)(3)}(B-alpha-PW(9)O(34))]7 H(2)O (4), [{Ni(6)(mu(3)-OH)(3)(en)(3)(H(2)O)(6)}(B-alpha-PW(9)O(34))]7 H(2)O (5), [{Ni(6)(mu(3)-OH)(3)(en)(2)(H(2)O)(8)}(B-alpha-PW(9)O(34))]7 H(2)O (6), [{Ni(6)(mu(3)-OH)(3)(dap)(2)(H(2)O)(8)}(B-alpha-PW(9)O(34))] 7 H(2)O (7), and [{Ni(6)(mu(3)-OH)(3)(en)(3)(H(2)O)(6)}(B-alpha-SiW(9)O(34))][Ni(0.5)(en)] 3.5 H(2)O (8) (en=ethylenediamine, dap=1,2-diaminopropane). These compounds have been structurally characterized by elemental analyses, IR spectra, diffuse reflectance spectra, thermogravimatric analysis, and X-ray crystallography. The double-cluster complex of phosphotungstate 1 simultaneously contains hepta- and hexa-Ni(II)-substituted trivacant Keggin units [{Ni(7)(mu(3)-OH)(3)O(2)(dap)(3)(H(2)O)(6)}(B-alpha-PW(9)O(34))](2-) and [{Ni(6)(mu(3)-OH)(3)(dap)(3)(H(2)O)(6)}(B-alpha-PW(9)O(34))]. The dimeric silicotungstate 2 is built up from two trivacant Keggin [B-alpha-SiW(9)O(34)](10-) fragments linked by an octa-Cu(II) cluster. The main skeleton of 3 is a tetrameric cluster constructed from four tri-Fe(III)-substituted [Fe(III) (3)(mu(3)-OH)(3)(B-alpha-PW(9) O(34))](3-) Keggin units linked by a central Fe(II) (4)O(4) cubane core and four mu(4)-PO(4) bridges. Complex 4 is an unprecedented three-dimensional extended architecture with hexagonal channels built by hexa-Cu(II) clusters and trivacant
Three-dimensional blade vortex interactions
Davoudzadeh, Farhad; Buggein, Richard C.; Shamroth, Stephen J.; Kitaplioglu, Cahit
1991-01-01
A three-dimensional time dependent Navier-Stokes analysis was applied to the rotor blade vortex interaction problem. The numerical procedure is an iterative implicit procedure using three point central differences to represent spatial derivatives. A series of calculations were made to determine the time steps, pseudo-time steps, iterations, artificial dissipation level, etc. required to maintain a nondissipative vortex. Results show the chosen method to have excellent non-dissipative properties provided the correct parameters are chosen. This study was used to set parameters for both two- and three-dimensional blade vortex interaction studies. The case considered was the interaction between a vortex and a NACA0012 airfoil. The results showed the detailed physics during the interaction including the pressure pulse propagating from the blade. The simulated flow physics was qualitatively similar to that experimentally observed. The BVI phenomena is the result of the buildup and violent collapse of the shock waves and local supersonic pockets on the blade surfaces. The resulting pressure pulse build-up appears to be centered at the blade leading edge.
Three-dimensional television: a broadcaster's perspective
Jolly, S. J. E.; Armstrong, M.; Salmon, R. A.
2009-02-01
The recent resurgence of interest in the stereoscopic cinema and the increasing availability to the consumer of stereoscopic televisions and computer displays are leading broadcasters to consider, once again, the feasibility of stereoscopic broadcasting. High Definition Television is now widely deployed, and the R&D departments of broadcasters and consumer electronics manufacturers are starting to plan future enhancements to the experience of television. Improving the perception of depth via stereoscopy is a strong candidate technology. In this paper we will consider the challenges associated with the production, transmission and display of different forms of "three-dimensional" television. We will explore options available to a broadcaster wishing to start a 3D service using the technologies available at the present time, and consider how they could be improved to enable many more television programmes to be recorded and transmitted in a 3D-compatible form, paying particular attention to scenarios such as live broadcasting, where the workflows developed for the stereoscopic cinema are inapplicable. We will also consider the opportunities available for broadcasters to reach audiences with "three-dimensional" content via other media in the near future: for example, distributing content via the existing stereoscopic cinema network, or over the Internet to owners of stereoscopic computer displays.
Tailoring thermal conductivity via three-dimensional porous alumina.
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.
Tailoring thermal conductivity via three-dimensional porous alumina
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
Full three-dimensional isotropic transformation media
García-Meca, C.; Ortuño, R.; Martí, J.; Martínez, A.
2014-02-01
We present a method that enables the implementation of full three-dimensional (3D) transformation media with minimized anisotropy. It is based on a special kind of shape-preserving mapping and a subsequent optimization process. For sufficiently smooth transformations, the resulting anisotropy can be neglected, paving the way for practically realizable 3D devices. The method is independent of the considered wave phenomenon and can thus be applied to any field for which a transformational technique exists, such as acoustics or thermodynamics. Full 3D isotropy has an additional important implication for optical transformation media, as it eliminates the need for magnetic materials in many situations. To illustrate the potential of the method, we design 3D counterparts of transformation-based electromagnetic squeezers and bends.
Three-dimensional printing physiology laboratory technology.
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.
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.
Dual solutions for three-dimensional
Directory of Open Access Journals (Sweden)
C.S.K. Raju
2016-03-01
Full Text Available In this study we investigated the effect of space and temperature dependent heat generation/absorption on three-dimensional magnetohydrodynamic nanofluid flow over a nonlinearly permeable stretching sheet. After using appropriate self-similarity transformation the governing equations are solved numerically using bvp4c Matlab package. The effects of the non-dimensional governing parameters on velocity, temperature and concentration profiles are discussed with the help of graphs. Also, coefficient of skin friction and Nusselt number is analyzed and presented through tables. It is found that present results have an excellent agreement with the existed studies under some special cases. Results indicate that an increase in space and temperature dependent heat source or sink increases the temperature and concentration profiles of the flow. Dual solutions exist only for certain range of power-law index.
Three-dimensional elastic lidar winds
Energy Technology Data Exchange (ETDEWEB)
Buttler, W.T.
1996-07-01
Maximum cross-correlation techniques have been used with satellite data to estimate winds and sea surface velocities for several years. Los Alamos National Laboratory (LANL) is currently using a variation of the basic maximum cross-correlation technique, coupled with a deterministic application of a vector median filter, to measure transverse winds as a function of range and altitude from incoherent elastic backscatter lidar data taken throughout large volumes within the atmospheric boundary layer. Hourly representations of three- dimensional wind fields, derived from elastic lidar data taken during an air-quality study performed in a region of complex terrain near Sunland Park, New Mexico, are presented and compared with results from an Environmental Protection Agency (EPA) approved laser doppler velocimeter. The wind fields showed persistent large scale eddies as well as general terrain following winds in the Rio Grande valley.
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
Three-dimensional printing of biological matters
Directory of Open Access Journals (Sweden)
Ahmed Munaz
2016-03-01
Full Text Available Three-dimensional (3D printing of human tissues and organ has been an exciting research topic in the past three decades. However, existing technological and biological challenges still require a significant amount of research. The present review highlights these challenges and discusses their potential solutions such as mapping and converting a human organ onto a 3D virtual design, synchronizing the virtual design with the printing hardware. Moreover, the paper discusses in details recent advances in formulating bio-inks and challenges in tissue construction with or without scaffold. Next, the paper reviews fusion processes effecting vascular cells and tissues. Finally, the paper deliberates the feasibility of organ printing with state-of-the-art technologies.
Three-dimensional hologram display system
Mintz, Frederick (Inventor); Chao, Tien-Hsin (Inventor); Bryant, Nevin (Inventor); Tsou, Peter (Inventor)
2009-01-01
The present invention relates to a three-dimensional (3D) hologram display system. The 3D hologram display system includes a projector device for projecting an image upon a display medium to form a 3D hologram. The 3D hologram is formed such that a viewer can view the holographic image from multiple angles up to 360 degrees. Multiple display media are described, namely a spinning diffusive screen, a circular diffuser screen, and an aerogel. The spinning diffusive screen utilizes spatial light modulators to control the image such that the 3D image is displayed on the rotating screen in a time-multiplexing manner. The circular diffuser screen includes multiple, simultaneously-operated projectors to project the image onto the circular diffuser screen from a plurality of locations, thereby forming the 3D image. The aerogel can use the projection device described as applicable to either the spinning diffusive screen or the circular diffuser screen.
On three-dimensional misorientation spaces
Krakow, Robert; Bennett, Robbie J.; Johnstone, Duncan N.; Vukmanovic, Zoja; Solano-Alvarez, Wilberth; Lainé, Steven J.; Einsle, Joshua F.; Midgley, Paul A.; Rae, Catherine M. F.; Hielscher, Ralf
2017-10-01
Determining the local orientation of crystals in engineering and geological materials has become routine with the advent of modern crystallographic mapping techniques. These techniques enable many thousands of orientation measurements to be made, directing attention towards how such orientation data are best studied. Here, we provide a guide to the visualization of misorientation data in three-dimensional vector spaces, reduced by crystal symmetry, to reveal crystallographic orientation relationships. Domains for all point group symmetries are presented and an analysis methodology is developed and applied to identify crystallographic relationships, indicated by clusters in the misorientation space, in examples from materials science and geology. This analysis aids the determination of active deformation mechanisms and evaluation of cluster centres and spread enables more accurate description of transformation processes supporting arguments regarding provenance.
Three-dimensional analysis of facial morphology.
Liu, Yun; Kau, Chung How; Talbert, Leslie; Pan, Feng
2014-09-01
The objectives of this study were to evaluate sexual dimorphism for facial features within Chinese and African American populations and to compare the facial morphology by sex between these 2 populations. Three-dimensional facial images were acquired by using the portable 3dMDface System, which captured 189 subjects from 2 population groups of Chinese (n = 72) and African American (n = 117). Each population was categorized into male and female groups for evaluation. All subjects in the groups were aged between 18 and 30 years and had no apparent facial anomalies. A total of 23 anthropometric landmarks were identified on the three-dimensional faces of each subject. Twenty-one measurements in 4 regions, including 19 distances and 2 angles, were not only calculated but also compared within and between the Chinese and African American populations. The Student's t-test was used to analyze each data set obtained within each subgroup. Distinct facial differences were presented between the examined subgroups. When comparing the sex differences of facial morphology in the Chinese population, significant differences were noted in 71.43% of the parameters calculated, and the same proportion was found in the African American group. The facial morphologic differences between the Chinese and African American populations were evaluated by sex. The proportion of significant differences in the parameters calculated was 90.48% for females and 95.24% for males between the 2 populations. The African American population had a more convex profile and greater face width than those of the Chinese population. Sexual dimorphism for facial features was presented in both the Chinese and African American populations. In addition, there were significant differences in facial morphology between these 2 populations.
Chen, Xiaobin; Du, Ke; Lai, Yanqing; Shang, Guozhi; Li, Huangxu; Xiao, Zhiwei; Chen, Yuxiang; Li, Junming; Zhang, Zhian
2017-07-01
Na2FeP2O7, which is considered as a promising cathode for sodium ion batteries (SIBs) on account of its economical efficiency and outstanding thermal stability, has been widely studied for the purpose of enhancing its electronic conductivity and interface ion transportation. In this paper, a double-carbon synergistically modified strategy was firstly introduced to facilitate the electrochemical performance of Na2FeP2O7. Na2FeP2O7 particles are enwrapped in situ by a carbon layer and further anchored in reduced graphene oxide (RGO) framework through a facile urea-nitrate combustion method. Consequently, the excellent rate performance and durable cycle stability of this compound are identified, which exhibits a reversible sodium storage capacity of 65 mAh g-1 at a current density of 10 C and no obvious decay in capacity after circling for 300 cycles at 1 C. What's more, no drastic degradation in capacity is observed when the cycling current density is brought back to high rates after cycling for more than 360 cycles at various rates.
Glidewell; Ferguson; Gregson; Campana
2000-02-01
Bis(2-aminoethyl)amine-4,4'-sulfonyldiphenol (1/3) (1) (orthorhombic Pccn with Z' = 0.5) is a salt, [HN(CH2CH2NH3)2]2+.[O2S(C6H4O)2-.[O2S(C6H4OH)2]2, containing both dianionic and neutral bis-phenol units. The neutral and anionic bis-phenol units are linked by strong O-H...O- hydrogen bonds to form ladders built from R4(4)(48) rings: each ladder is interwoven with its two nearest neighbours to form a continuous two-dimensional sheet. The amine cations play two roles: they link each ladder to its two next-nearest neighbours by means of N-H...O hydrogen bonds and they also link each sheet to the two neighbouring sheets, again via N-H...O hydrogen bonds, thus generating a three-dimensional framework. Bis(2-aminoethyl)amine-1,1,1-tris(4-hydroxyphenyl)ethane-methanol (1/4/1) (2) (triclinic P1 with Z' = 0.5) consists entirely of neutral fragments. The tris-phenol units are linked by O-H...O hydrogen bonds into molecular ladders built from R4(4)(48) rings: these ladders are linked by the amine units, firstly into sheets and thence into a three-dimensional framework. Bis(2-aminoethyl)amine-3,5-dihydroxybenzoic acid (1/2) (3) (monoclinic P2(1)/c with Z' = 1) is a salt [HN(CH2CH2NH3)2]2+.[[(HO)2C6H3COO]-]2. The 3,5-dihydroxybenzoate anions are linked by O-H...O hydrogen bonds into interwoven and cross-connected (001) sheets linked by further O-H...O hydrogen bonds into a three-dimensional framework. The (001) sheets are further linked by ladders formed from both cations and anions. Tris(2-aminoethyl)amine-4,4'-biphenol-methanol (1/3/1), (4) (monoclinic P2(1)), is a salt [((H2NCH2CH2)2.N(CH2CH2NH3)]+]2.[OC6H4C6H4O]2.[HOC6H4C6H4OH]5.[MeOH]2, with Z' = 1. The asymmetric unit, containing ten independent molecular components, can be regarded as a supermolecule held together by a total of 13 independent hydrogen bonds, of O-H...O, O-H...N and N-H...O types. The supermolecules are linked by O-H...O and N-H...O hydrogen bonds into two-dimensional sheets, generated by translation
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...
Characterizing College Science Assessments: The Three-Dimensional Learning Assessment Protocol
Laverty, James T; Matz, Rebecca L; Posey, Lynmarie A; Carmel, Justin H; Caballero, Marcos D; Fata-Hartley, Cori L; Ebert-May, Diane; Jardeleza, Sarah E; Cooper, Melanie M
2016-01-01
Many calls to improve science education in college and university settings have focused on improving instructor pedagogy. Meanwhile, science education at the K-12 level is undergoing significant changes as a result of the emphasis on scientific and engineering practices, crosscutting concepts, and disciplinary core ideas. This framework of "three-dimensional learning" is based on the literature about how people learn science and how we can help students put their knowledge to use. Recently, calls have been made to bring similar changes to higher education by incorporating three-dimensional learning into college science courses. As these transformations move forward, it will become important to assess three-dimensional learning both to align assessments with the learning environment, and to assess the extent of the transformations. In this paper, we introduce the Three-Dimensional Learning Assessment Protocol (3D-LAP), which is designed to characterize and support the development of assessment tasks in biology...
Scaling Laws for the Propulsive Performance of Self-Propelled Three-Dimensional Pitching Panels
Ayancik, Fatma; Moored, Keith
2017-11-01
Inviscid computational results are presented within a boundary element numerical framework on a self-propelled virtual body combined with a rigid three-dimensional rectangular plate undergoing pitching motions about its leading edge. New scaling laws have been developed for the thrust and power as well as self-propelled speed, efficiency, and cost of transport by incorporating three-dimensional effects for varying aspect ratios. A lifting line theory correction is applied to account for the variation of the circulatory forces due to three-dimensional effects and the alteration of the added mass forces with aspect ratio changes is also considered. The scaling laws show that when accounting for three-dimensional effects, the physics of mean thrust production follows linear theory well, while the power must be modified with nonlinear corrections. Supported by the Office of Naval Research under Program Director Dr. Bob Brizzola, MURI Grant Number N00014-14-1-0533.
Primary and Secondary Three Dimensional Microbatteries
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
Understanding three-dimensional damage envelopes
Browning, John; Harland, Sophie; Meredith, Philip; Healy, David; Mitchell, Tom
2017-04-01
Microcrack damage leading to failure in rocks evolves in response to differential loading. This loading is often visualized in a two-dimensional stress space through the use of Mohr-Coulomb diagrams. The vast majority of experimental studies investigate damage evolution and rock failure using conventional triaxial stress states (σ1 > σ2 = σ3) in which the results can be easily represented in a Mohr-Coulomb plot. However, in nature the stress state is in general truly triaxial (σ1 > σ2 > σ3) and as such comprises a 3D stress state potentially leading to more complexity. By monitoring acoustic wave velocities and acoustic emissions we have shown that damage is generated in multiple orientations depending on the loading directions and hence principal stress directions. Furthermore, crack growth is shown to be a function of differential stress regardless of the mean stress. As such, new cracks can form due to a decrease in the minimum principal stress, which reduces mean stress but increases the differential stress. Although the size of individual cracks is not affected by the intermediate principal stress it has been shown that the σ2 plays a key role in suppressing the total amount of crack growth and concentrates this damage in a single plane. Hence, the differential stress at which rocks fail (i.e. the rock strength) will be significantly increased under true triaxial stress conditions than under the much more commonly applied condition of conventional triaxial stress. Through a series of cyclic loading tests we investigated the Kaiser effect, we show that while individual stress states are important, the stress path by which this stress state is reached is equally important. Whether or not a stress state has been 'visited' before is also vitally important in determining and understanding damage envelopes. Finally, we show that damage evolution can be anisotropic and must be considered as a three-dimensional problem. It is unclear how damage envelopes
Three-Dimensional Printed Thermal Regulation Textiles.
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
2017-11-01
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.
Three dimensional characterization and archiving system
Energy Technology Data Exchange (ETDEWEB)
Sebastian, R.L.; Clark, R.; Gallman, P. [Coleman Research Corp., Springfield, VA (United States)] [and others
1995-10-01
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. The 3D-ICAS system robotically conveys a multisensor probe near the surface to be inspected. The sensor position and orientation are monitored and controlled by Coherent laser radar (CLR) tracking. The ICAS fills the need for high speed automated organic analysis by means of gas chromatography-mass spectrometry sensors, and also by radionuclide sensors which combines alpha, beta, and gamma counting.
Magnetophotonic response of three-dimensional opals.
Caicedo, José Manuel; Pascu, Oana; López-García, Martín; Canalejas, Víctor; Blanco, Alvaro; López, Cefe; Fontcuberta, Josep; Roig, Anna; Herranz, Gervasi
2011-04-26
Three-dimensional magnetophotonic crystals (3D-MPCs) are being postulated as appropriate platforms to tailor the magneto-optical spectral response of magnetic materials and to incorporate this functionality in a new generation of optical devices. By infiltrating self-assembled inverse opal structures with monodisperse nickel nanoparticles we have fabricated 3D-MPCs that show a sizable enhancement of the magneto-optical signal at frequencies around the stop-band edges of the photonic crystals. We have established a proper methodology to disentangle the intrinsic magneto-optical spectra from the nonmagnetic optical activity of the 3D-MPCs. The results of the optical and magneto-optical characterization are consistent with a homogeneous magnetic infiltration of the opal structure that gives rise to both a red-shift of the optical bandgap and a modification of the magneto-optical spectral response due to photonic bandgap effects. The results of our investigation demonstrate the potential of 3D-MPCs fabricated following the approach outlined here and offer opportunities to adapt the magneto-optical spectral response at optical frequencies by appropriate design of the opal structure or magnetic field strength.
a Three-Dimensional Orbit for Capella
Branham, Richard L.
2008-09-01
Semidefinite programming is applied to 169 interferometric observations of Capella, made between 1919 and 1999, and 221 double-line radial velocities, obtained between 1896 and 1991, to calculate a three-dimensional orbit. The data are reduced with the robust L 1 criterion. The orbit is nearly circular, eccentricity of 0.00508, with a semimajor axis of 0farcs056 and period of 104.039 days. The mass of the primary is calculated to be 3.049 M sun, that of the secondary 2.569 M sun, and the parallax of the system is calculated to be 74.85 mas. Another orbit is calculated, but using only the best data, Mark III interferometric observations, and Coralie radial velocities. Although the mean errors for this orbit are considerably smaller, reasons are given for preferring the orbit calculated from all of the data as opposed to only the best data: the residuals are more random, the parallax agrees better with van Leeuwen's re-reduction of the Hipparcos parallax, and the Shannon uncertainty is lower.
Two and three dimensional magnetotelluric inversion
Energy Technology Data Exchange (ETDEWEB)
Booker, J.
1993-01-01
Electrical conductivity depends on properties such as the presence of ionic fluids in interconnected pores that are difficult to sense with other remote sensing techniques. Thus improved imaging of underground electrical structure has wide practical importance in exploring for groundwater, mineral and geothermal resources, and in assessing the diffusion of fluids in oil fields and waste sites. Because the electromagnetic inverse problem is fundamentally multi-dimensional, most imaging algorithms saturate available computer power long before they can deal with the complete data set. We have developed an algorithm to directly invert large multi-dimensional data sets that is orders of magnitude faster than competing methods. We have proven that a two-dimensional (2D) version of the algorithm is highly effective for real data and have made substantial progress towards a three-dimensional (3D) version. We are proposing to cure identified shortcomings and substantially expand the utility of the existing 2D program, overcome identified difficulties with extending our method to three-dimensions (3D) and embark on an investigation of related EM imaging techniques which may have the potential for even further increasing resolution.
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.
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.
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.
Nanoscale three-dimensional single particle tracking.
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.
Three-Dimensional Ultrasonography: Case Report
Directory of Open Access Journals (Sweden)
Edward Araujo Júnior
2012-01-01
Full Text Available The numbers of syphilis cases have been increasing considerably, especially in eastern europe, thereby contributing towards greater chances of cases of congenital syphilis. Some of the complications of congenital syphilis can be detected on two-dimensional ultrasonography (2DUS, and these are generally manifested in the second trimester of pregnancy. The commonest ultrasonographic signs are hepatosplenomegaly, placentomegaly, and fetal growth restriction, while lower-frequency occurrences include intrahepatic calcifications, ascites, fetal hydrops, and even fetal death. Three-dimensional ultrasonography (3DUS is a relatively new imaging technique that is adjuvant to 2DUS and enables detailed assessment of the fetal surface anatomy. We present a case of a 21-year-old primigravida with a diagnosis of congenital syphilis, with obstetric 2DUS findings of hepatosplenomegaly, ascites, pericardial effusion and hyperechogenicity of the cerebral parenchyma. 3DUS in rendering mode allowed clear assessment of the fetal limbs, especially the feet, which appeared twisted and lacked some toes. It allowed the parents to understand the pathological condition better and improved prenatal management and neonatal followup. 3DUS can be used routinely for assessing fetal malformations resulting from congenital infections.
Three-dimensional simulations of fracture dissolution
Starchenko, Vitaliy; Marra, Cameron J.; Ladd, Anthony J. C.
2016-09-01
Numerical studies of fracture dissolution are frequently based on two-dimensional models, where the fracture geometry is represented by an aperture field h(x,y). However, it is known that such models can break down when the spatial variations in aperture are rapid or large in amplitude; for example, in a rough fracture or when instabilities in the dissolution front develop into pronounced channels (or wormholes). Here we report a finite-volume implementation of a three-dimensional reactive transport model using the OpenFOAM® toolkit. Extensions to the OpenFOAM source code have been developed which displace and then relax the mesh in response to variations in the surface concentration; up to 100-fold increases in fracture aperture are possible without remeshing. Our code has simulated field-scale fractures with physical dimensions of about 10 m. We report simulations of smooth fractures, with small, well-controlled perturbations in fracture aperture introduced at the inlet. This allows for systematic convergence studies and for detailed comparisons with results from a two-dimensional model. Initially, the fracture aperture develops similarly in both models, but as local inhomogeneities develop the results start to diverge. We investigate numerically the onset of instabilities in the dissolution of fractures with small random variations in the initial aperture field. Our results show that elliptical cross sections, which are characteristic of karstic conduits, can develop very rapidly, on time scales of 10-20 years in calcite rocks.
Clinical significance of three-dimensional sonohysterography
Energy Technology Data Exchange (ETDEWEB)
Lee, Eun Hye; Lee, Mi Hwa; Lee, Chan; Kim, Jong Wook; Shin, Myung Choel [Pochon Cha University College of Medicine, Pochon (Korea, Republic of)
1999-12-15
To evaluate the usefulness of three dimensional sonohysterography (3D SHG) in the evaluation of uterine endometrial and submucosal lesions in comparison with conventional two-dimensional sonohysterography (2D SHG). Our series consisted of 26 patients (mean aged 41 years) who complained of uterine bleeding, menorrhagia, or dysmenorrhea. 2D SHG was performed, and then 3D SHG was done after the volume mode was switched on. Simultaneous display of three perpendicular two-dimensional planes and surface rendering of findings on particular section were obtained. We analyzed whether the endometrium was thickened or not, and the location, size, shape, echogenicity, posterior shadowing, and echogenic rim of the focal lesion. The results were compared with the pathologic findings or MRI. There were submucosal myomas (n=12), intramural myomas (n=2), endometrial polyps (n=7), placental polyp (n=1), and normal endometrial cavities (n=4) on SHG. Nineteen cases were confirmed by pathologic findings or MRI. The results were correlated in 89% (17/19) of the cases. We misdiagnosed 2 cases: focal endometrial hyperplasia and choriocarcinoma were misdiagnosed as endometrial polyp and placental polyp, respectively. Imaging diagnoses were same in the techniques. Comparing with 2D SHG, 3D SHG provided a subjective display of pathologic findings and an additional information about spatial relationship between focal lesion and surroundings.
FRET Imaging in Three-dimensional Hydrogels.
Donius, Amalie E; Bougoin, Sylvain V; Taboas, Juan M
2016-08-01
Imaging of Förster resonance energy transfer (FRET) is a powerful tool for examining cell biology in real-time. Studies utilizing FRET commonly employ two-dimensional (2D) culture, which does not mimic the three-dimensional (3D) cellular microenvironment. A method to perform quenched emission FRET imaging using conventional widefield epifluorescence microscopy of cells within a 3D hydrogel environment is presented. Here an analysis method for ratiometric FRET probes that yields linear ratios over the probe activation range is described. Measurement of intracellular cyclic adenosine monophosphate (cAMP) levels is demonstrated in chondrocytes under forskolin stimulation using a probe for EPAC1 activation (ICUE1) and the ability to detect differences in cAMP signaling dependent on hydrogel material type, herein a photocrosslinking hydrogel (PC-gel, polyethylene glycol dimethacrylate) and a thermoresponsive hydrogel (TR-gel). Compared with 2D FRET methods, this method requires little additional work. Laboratories already utilizing FRET imaging in 2D can easily adopt this method to perform cellular studies in a 3D microenvironment. It can further be applied to high throughput drug screening in engineered 3D microtissues. Additionally, it is compatible with other forms of FRET imaging, such as anisotropy measurement and fluorescence lifetime imaging (FLIM), and with advanced microscopy platforms using confocal, pulsed, or modulated illumination.
Quantitative volumetric Raman imaging of three dimensional cell cultures
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.
Quantitative volumetric Raman imaging of three dimensional cell cultures
Kallepitis, Charalambos; Bergholt, Mads S.; Mazo, Manuel M.; Leonardo, Vincent; Skaalure, Stacey C.; Maynard, Stephanie A.; Stevens, Molly M.
2017-03-01
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.
A three-dimensional carbon nanotube network for water treatment
Camilli, L.; Pisani, C.; Gautron, E.; Scarselli, M.; Castrucci, P.; D'Orazio, F.; Passacantando, M.; Moscone, D.; De Crescenzi, M.
2014-02-01
The bulk synthesis of freestanding carbon nanotube (CNT) frameworks is developed through a sulfur-addition strategy during an ambient-pressure chemical vapour deposition process, with ferrocene used as the catalyst precursor. This approach enhances the CNTs’ length and contorted morphology, which are the key features leading to the formation of the synthesized porous networks. We demonstrate that such a three-dimensional structure selectively uptakes from water a mass of toxic organic solvent (i.e. o-dichlorobenzene) about 3.5 times higher than that absorbed by individual CNTs. In addition, owing to the presence of highly defective nanostructures constituting them, our samples exhibit an oil-absorption capacity higher than that reported in the literature for similar CNT sponges.
Application of Simulated Three Dimensional CT Image in Orthognathic Surgery
Energy Technology Data Exchange (ETDEWEB)
Kim, Hyun Don; Park, Chang Seo [Dept. of Dental Radiology, College of Dentistry, Yensei University, Seoul (Korea, Republic of); Yoo, Sun Kook; Lee, Kyoung Sang [Dept. of Medical Engineering, College of Medicine, Yensei University, Seoul (Korea, Republic of)
1998-08-15
In orthodontics and orthognathic surgery, cephalogram has been routine practice in diagnosis and treatment evaluation of craniofacial deformity. But its inherent distortion of actual length and angles during projecting three dimensional object to two dimensional plane might cause errors in quantitative analysis of shape and size. Therefore, it is desirable that three dimensional object is diagnosed and evaluated three dimensionally and three dimensional CT image is best for three dimensional analysis. Development of clinic necessitates evaluation of result of treatment and comparison before and after surgery. It is desirable that patient that was diagnosed and planned by three dimensional computed tomography before surgery is evaluated by three dimensional computed tomography after surgery, too. But Because there is no standardized normal values in three dimension now and three dimensional Computed Tomography needs expensive equipment and because of its expenses and amount of exposure to radiation, limitations still remain to be solved in its application to routine practice. If postoperative three dimensional image is constructed by pre and postoperative lateral and postero-anterior cephalograms and preoperative three dimensional computed tomogram, pre and postoperative image will be compared and evaluated three dimensionally without three dimensional computed tomography after surgery and that will contribute to standardize normal values in three dimension. This study introduced new method that computer-simulated three dimensional image was constructed by preoperative three dimensional computed tomogram and pre and postoperative lateral and postero-anterior cephalograms, and for validation of new method, in four cases of dry skull that position of mandible was displaced and four patients of orthognathic surgery, computer-simulated three dimensional image and actual postoperative three dimensional image were compared. The results were as follows. 1. In four cases of
A method for three-dimensional color printing and a three-dimensional color printing device
Urban, Philipp; Brunton, Alan; Arikan, Can Ates
2016-01-01
The invention relates to a method and a device for three-dimensional color printing, wherein at least a first printing material with a first printing material color and at least another printing material with another printing material color is used to construct a printing object (7), wherein an arrangement of the printing materials in a surface region and a near surface interior region of the printing object (7) is determined based on a desired color reproduction of the printing object.
Panoramic three-dimensional CT imaging
Energy Technology Data Exchange (ETDEWEB)
Kawamata, Akitoshi; Fujishita, Masami [Asahi Univ., Hozumi, Gifu (Japan). School of Dentistry
1998-09-01
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)
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.
Three-dimensional structure of Theiler virus.
Grant, R A; Filman, D J; Fujinami, R S; Icenogle, J P; Hogle, J M
1992-01-01
Theiler murine encephalomyelitis virus strains are categorized into two groups, a neurovirulent group that rapidly kills the host, and a demyelinating group that causes a generally nonlethal infection of motor neurons followed by a persistent infection of the white matter with demyelinating lesions similar to those found in multiple sclerosis. The three-dimensional structure of the DA strain, a member of the demyelinating group, has been determined at 2.8 A resolution. As in other picornaviruses, the icosahedral capsid is formed by the packing of wedge-shaped eight-stranded antiparallel beta barrels. The surface of Theiler virus has large star-shaped plateaus at the fivefold axes and broad depressions spanning the twofold axes. Several unusual structural features are clustered near one edge of the depression. These include two finger-like loops projecting from the surface (one formed by residues 78-85 of VP1, and the other formed by residues 56-65 of VP3) and a third loop containing three cysteines (residues 87, 89, and 91 of VP3), which appear to be covalently modified. Most of the sequence differences between the demyelinating and neurovirulent groups that could play a role in determining pathogenesis map to the surface of the star-shaped plateau. The distribution of these sequence differences on the surface of the virion is consistent with models in which the differences in the pathogenesis of the two groups of Theiler viruses are the result of differences in immunological or receptor-mediated recognition processes. Images PMID:1549565
Three-dimensional image display in medicine.
Mankovich, N J; Robertson, D R; Cheeseman, A M
1990-05-01
This article is a tutorial on the methods used to create three-dimensional (3-D) images for use in displaying patient anatomy. This new view into anatomy has developed over the last 10 years from the need of surgeons, radiation therapists, and radiologists to integrate the many images resulting from the recent growth in tomographic imaging including computed tomography (CT) and magnetic resonance imaging (MRI). CT and MRI studies result in 30 to 100 images. 3-D imaging processes and integrates this image data volume and extracts more meaningful, derivative images via multiplanar reconstruction (MPR), shaded surface processing, or volumetric processing. MPR reslices the image volume to produce novel views of patient anatomy while retaining the image voxel intensities. Realistic shaded surface display of 3-D objects can involve extensive processing of the images to create computer representations of objects rendered into a displayable 3-D scene. Volumetric imaging combines the voxel processing of MPR with the techniques of tissue classification and surface shading to produce novel projections of the image data volume that allow automated creation of 3-D scenes without recourse to the complexities of object delineation. As the ultimate 3-D display, recent advances in computer-aided design (CAD) and computer-aided manufacturing (CAM) allow the fabrication of physical models of anatomy using computer-controlled milling machines. New technology that actually builds the model layer by layer from a liquid plastic offers the possibility of complete models with intact internal anatomy. The growth in 3-D is certain as hardware and software costs decrease and medical professionals find further applications for this technology.
A new three-dimensional topology optimization method based on moving morphable components (MMCs)
Zhang, Weisheng; Li, Dong; Yuan, Jie; Song, Junfu; Guo, Xu
2017-04-01
In the present paper, a new method for solving three-dimensional topology optimization problem is proposed. This method is constructed under the so-called moving morphable components based solution framework. The novel aspect of the proposed method is that a set of structural components is introduced to describe the topology of a three-dimensional structure and the optimal structural topology is found by optimizing the layout of the components explicitly. The standard finite element method with ersatz material is adopted for structural response analysis and the shape sensitivity analysis only need to be carried out along the structural boundary. Compared to the existing methods, the description of structural topology is totally independent of the finite element/finite difference resolution in the proposed solution framework and therefore the number of design variables can be reduced substantially. Some widely investigated benchmark examples, in the three-dimensional topology optimization designs, are presented to demonstrate the effectiveness of the proposed approach.
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
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.
Advanced Three-Dimensional Display System
Geng, Jason
2005-01-01
A desktop-scale, computer-controlled display system, initially developed for NASA and now known as the VolumeViewer(TradeMark), generates three-dimensional (3D) images of 3D objects in a display volume. This system differs fundamentally from stereoscopic and holographic display systems: The images generated by this system are truly 3D in that they can be viewed from almost any angle, without the aid of special eyeglasses. It is possible to walk around the system while gazing at its display volume to see a displayed object from a changing perspective, and multiple observers standing at different positions around the display can view the object simultaneously from their individual perspectives, as though the displayed object were a real 3D object. At the time of writing this article, only partial information on the design and principle of operation of the system was available. It is known that the system includes a high-speed, silicon-backplane, ferroelectric-liquid-crystal spatial light modulator (SLM), multiple high-power lasers for projecting images in multiple colors, a rotating helix that serves as a moving screen for displaying voxels [volume cells or volume elements, in analogy to pixels (picture cells or picture elements) in two-dimensional (2D) images], and a host computer. The rotating helix and its motor drive are the only moving parts. Under control by the host computer, a stream of 2D image patterns is generated on the SLM and projected through optics onto the surface of the rotating helix. The system utilizes a parallel pixel/voxel-addressing scheme: All the pixels of the 2D pattern on the SLM are addressed simultaneously by laser beams. This parallel addressing scheme overcomes the difficulty of achieving both high resolution and a high frame rate in a raster scanning or serial addressing scheme. It has been reported that the structure of the system is simple and easy to build, that the optical design and alignment are not difficult, and that the
On two-dimensionalization of three-dimensional turbulence in shell models
DEFF Research Database (Denmark)
Chakraborty, Sagar; Jensen, Mogens Høgh; Sarkar, A.
2010-01-01
Applying a modified version of the Gledzer-Ohkitani-Yamada (GOY) shell model, the signatures of so-called two-dimensionalization effect of three-dimensional incompressible, homogeneous, isotropic fully developed unforced turbulence have been studied and reproduced. Within the framework of shell...
An Exploration of Three-Dimensional Integrated Assessment for Computational Thinking
Zhong, Baichang; Wang, Qiyun; Chen, Jie; Li, Yi
2016-01-01
Computational thinking (CT) is a fundamental skill for students, and assessment is a critical factor in education. However, there is a lack of effective approaches to CT assessment. Therefore, we designed the Three-Dimensional Integrated Assessment (TDIA) framework in this article. The TDIA has two aims: one was to integrate three dimensions…
Scaling up Three-Dimensional Science Learning through Teacher-Led Study Groups across a State
Reiser, Brian J.; Michaels, Sarah; Moon, Jean; Bell, Tara; Dyer, Elizabeth; Edwards, Kelsey D.; McGill, Tara A. W.; Novak, Michael; Park, Aimee
2017-01-01
The vision for science teaching in the Framework for K-12 Science Education and the Next Generation Science Standards requires a radical departure from traditional science teaching. Science literacy is defined as three-dimensional (3D), in which students engage in science and engineering practices to develop and apply science disciplinary ideas…
Three-dimensional metal scaffold supported bicontinuous silicon battery anodes.
Zhang, Huigang; Braun, Paul V
2012-06-13
Silicon-based lithium ion battery anodes are attracting significant attention because of silicon's exceptionally high lithium capacity. However, silicon's large volume change during cycling generally leads to anode pulverization unless the silicon is dispersed throughout a matrix in nanoparticulate form. Because pulverization results in a loss of electric connectivity, the reversible capacity of most silicon anodes dramatically decays within a few cycles. Here we report a three-dimensional (3D) bicontinuous silicon anode formed by depositing a layer of silicon on the surface of a colloidal crystal templated porous nickel metal scaffold, which maintains electrical connectivity during cycling due to the scaffold. The porous metal framework serves to both impart electrical conductivity to the anode and accommodate the large volume change of silicon upon lithiation and delithiation. The initial capacity of the bicontinuous silicon anode is 3568 (silicon basis) and 1450 mAh g(-1) (including the metal framework) at 0.05C. After 100 cycles at 0.3C, 85% of the capacity remains. Compared to a foil-supported silicon film, the 3D bicontinuous silicon anode exhibits significantly improved mechanical stability and cycleability.
The minimum bisection width of (three-dimensional) blocks
Bodlaender, H.L.; Leeuwen, J. van
1984-01-01
We provide a proof of the following "folk" theorem in (three-dimensional) VLSI-theroy: given a v x w x 1 rectilinear block of the three-dimensional grid (v ≤ w ≤ 1 ), its minimum bisection is at least vw.
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....
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...
Pathogen propagation in cultured three-dimensional tissue mass
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.
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.
Quantitative three-dimensional ice roughness from scanning electron microscopy
Butterfield, Nicholas; Rowe, Penny M.; Stewart, Emily; Roesel, David; Neshyba, Steven
2017-03-01
We present a method for inferring surface morphology of ice from scanning electron microscope images. We first develop a novel functional form for the backscattered electron intensity as a function of ice facet orientation; this form is parameterized using smooth ice facets of known orientation. Three-dimensional representations of rough surfaces are retrieved at approximately micrometer resolution using Gauss-Newton inversion within a Bayesian framework. Statistical analysis of the resulting data sets permits characterization of ice surface roughness with a much higher statistical confidence than previously possible. A survey of results in the range -39°C to -29°C shows that characteristics of the roughness (e.g., Weibull parameters) are sensitive not only to the degree of roughening but also to the symmetry of the roughening. These results suggest that roughening characteristics obtained by remote sensing and in situ measurements of atmospheric ice clouds can potentially provide more facet-specific information than has previously been appreciated.
Three-dimensional tracking of objects in holographic imaging
DaneshPanah, Mehdi; Javidi, Bahram
2007-09-01
In this paper we overview on a three dimensional imaging and tracking algorithm in order to track biological specimen in sequence of holographic microscopy images. We use a region tracking method based on MAP estimator in a Bayesian framework and we adapt it to 3D holographic data sequences to efficiently track the desired microorganism. In our formulation, the target-background interface is modeled as the isolevel of a level set function which is evolved at each frame via level set update rule. The statistical characteristics of the target microorganism versus the background are exploited to evolve the interface from one frame to another. Using the bivariate Gaussian distribution to model the reconstructed hologram data enables one to take into account the correlation between the amplitude and phase of the reconstructed field to obtain a more accurate solution. Also, the level set surface evolution provides a robust, efficient and numerically stable method which deals automatically with the change in the topology and geometrical deformations that a microorganism may be subject to.
Three-dimensional neurophenotyping of adult zebrafish behavior.
Directory of Open Access Journals (Sweden)
Jonathan Cachat
Full Text Available The use of adult zebrafish (Danio rerio in neurobehavioral research is rapidly expanding. The present large-scale study applied the newest video-tracking and data-mining technologies to further examine zebrafish anxiety-like phenotypes. Here, we generated temporal and spatial three-dimensional (3D reconstructions of zebrafish locomotion, globally assessed behavioral profiles evoked by several anxiogenic and anxiolytic manipulations, mapped individual endpoints to 3D reconstructions, and performed cluster analysis to reconfirm behavioral correlates of high- and low-anxiety states. The application of 3D swim path reconstructions consolidates behavioral data (while increasing data density and provides a novel way to examine and represent zebrafish behavior. It also enables rapid optimization of video tracking settings to improve quantification of automated parameters, and suggests that spatiotemporal organization of zebrafish swimming activity can be affected by various experimental manipulations in a manner predicted by their anxiolytic or anxiogenic nature. Our approach markedly enhances the power of zebrafish behavioral analyses, providing innovative framework for high-throughput 3D phenotyping of adult zebrafish behavior.
The three-dimensional structures of bacterial reaction centers.
Olson, T L; Williams, J C; Allen, J P
2014-05-01
This review presents a broad overview of the research that enabled the structure determination of the bacterial reaction centers from Blastochloris viridis and Rhodobacter sphaeroides, with a focus on the contributions from Duysens, Clayton, and Feher. Early experiments performed in the laboratory of Duysens and others demonstrated the utility of spectroscopic techniques and the presence of photosynthetic complexes in both oxygenic and anoxygenic photosynthesis. The laboratories of Clayton and Feher led efforts to isolate and characterize the bacterial reaction centers. The availability of well-characterized preparations of pure and stable reaction centers allowed the crystallization and subsequent determination of the structures using X-ray diffraction. The three-dimensional structures of reaction centers revealed an overall arrangement of two symmetrical branches of cofactors surrounded by transmembrane helices from the L and M subunits, which also are related by the same twofold symmetry axis. The structure has served as a framework to address several issues concerning bacterial photosynthesis, including the directionality of electron transfer, the properties of the reaction center-cytochrome c 2 complex, and the coupling of proton and electron transfer. Together, these research efforts laid the foundation for ongoing efforts to address an outstanding question in oxygenic photosynthesis, namely the molecular mechanism of water oxidation.
A method for transient, three-dimensional neutron transport calculations
Energy Technology Data Exchange (ETDEWEB)
Waddell, M.W. Jr. (Oak Ridge Y-12 Plant, TN (United States)); Dodds, H.L. (Tennessee Univ., Knoxville, TN (United States))
1992-12-28
This paper describes the development and evaluation of a method for solving the time-dependent, three-dimensional Boltzmann transport model with explicit representation of delayed neutrons. A hybrid stochastic/deterministic technique is utilized with a Monte Carlo code embedded inside of a quasi-static kinetics framework. The time-dependent flux amplitude, which is usually fast varying, is computed deterministically by a conventional point kinetics algorithm. The point kinetics parameters, reactivity and generation time as well as the flux shape, which is usually slowly varying in time, are computed stochastically during the random walk of the Monte Carlo calculation. To verify the accuracy of this new method, several computational benchmark problems from the Argonne National Laboratory benchmark book, ANL-7416, were calculated. The results are shown to be in reasonably good agreement with other independently obtained solutions. The results obtained in this work indicate that the method/code is working properly and that it is economically feasible for many practical applications provided a dedicated high performance workstation is available.
A method for transient, three-dimensional neutron transport calculations
Energy Technology Data Exchange (ETDEWEB)
Waddell, M.W. Jr. (Martin Marietta Energy Systems, Inc. (United States)); Dodds, H.L. (Univ. of Tennessee (United States))
1993-04-01
This paper describes the development and evaluation of a method for solving the time-dependent, three-dimensional Boltzmann transport model with explicit representation of delayed neutrons. A hybrid stochastic/deterministic technique is utilized with a Monte Carlo code embedded inside of a quasi-static kinetics framework. The time-dependent flux amplitude, which is usually fast varying, is computed deterministically by a conventional point kinetics algorithm. The point kinetics parameters, reactivity and generation time as well as the flux shape, which is usually slowly varying in time, are computed stochastically during the random walk of the Monte Carlo calculation. To verify the accuracy of this new method, several computational benchmark problems from the Argonne National Laboratory benchmark book, ANL-7416, were calculated. The results are shown to be in reasonably good agreement with other independently obtained solutions. The results obtained in this work indicate that the method/code is working properly and that it is economically feasible for many practical applications provided a dedicated high performance workstation is available. (orig.)
Fabrication of three-dimensional nanofibrous macrostructures by electrospinning
Directory of Open Access Journals (Sweden)
Ping Zhu
2016-05-01
Full Text Available Electrospinning has been widely used in fabricating nanofibers and nanofibrous membranes. Recently, the fabrication of three-dimensional (3D nanofibrous macrostructures has become a hot subject in the development of electrospinning technology. In this paper, the 3D nanofibrous macrostructure was constructed by using electrospinning apparatus with both dynamic and static 3D collecting templates. The effect of the governing parameters on the formation process of 3D macrostructure is studied, such as the applied voltage, the flow rate, the needle-tip-to-collector distance, and the rotating speed. It was found that laying the collecting device either in parallel or perpendicularly with some gap in between, would lead to orderly deposition of nanofibers. In this study, a “dumbbell” dynamic collector was used to fabricate special 3D macrostructures consisting of multilayers of fibrous membranes. By adjusting the rotating speed of the collector, the formation process of multilayer 3D macrostructure can be controlled. An umbrella-shaped static structure collector was used to fabricate 3D framework structures. It is feasible to fabricate various 3D nanofibrous structures via electrospinning with 3D collecting templates, which has great potential in tissue engineering.
Pliocene three-dimensional global ocean temperature reconstruction
Directory of Open Access Journals (Sweden)
H. J. Dowsett
2009-12-01
Full Text Available The thermal structure of the mid-Piacenzian ocean is obtained by combining the Pliocene Research, Interpretation and Synoptic Mapping Project (PRISM3 multiproxy sea-surface temperature (SST reconstruction with bottom water temperature estimates from 27 locations produced using Mg/Ca paleothermometry based upon the ostracod genus Krithe. Deep water temperature estimates are skewed toward the Atlantic Basin (63% of the locations and represent depths from 1000 m to 4500 m. This reconstruction, meant to serve as a validation data set as well as an initialization for coupled numerical climate models, assumes a Pliocene water mass framework similar to that which exists today, with several important modifications. The area of formation of present day North Atlantic Deep Water (NADW was expanded and extended further north toward the Arctic Ocean during the mid-Piacenzian relative to today. This, combined with a deeper Greenland-Scotland Ridge, allowed a greater volume of warmer NADW to enter the Atlantic Ocean. In the Southern Ocean, the Polar Front Zone was expanded relative to present day, but shifted closer to the Antarctic continent. This, combined with at least seasonal reduction in sea ice extent, resulted in decreased Antarctic Bottom Water (AABW production (relative to present day as well as possible changes in the depth of intermediate waters. The reconstructed mid-Piacenzian three-dimensional ocean was warmer overall than today, and the hypothesized aerial extent of water masses appears to fit the limited stable isotopic data available for this time period.
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.
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.
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...
Analysis and validation of carbohydrate three-dimensional structures
Lütteke, Thomas
2009-01-01
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. PMID:19171971
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.
Metric for three-dimensional alignment of molecules
Makhija, Varun; Ren, Xiaoming; Kumarappan, Vinod
2012-03-01
In an effort to clarify the three-dimensional alignment dynamics of polyatomic molecules, we propose a single measure for the degree of angular confinement of such molecules. The measure proposed for three-dimensional orientation is the angle of the single rotation that takes the molecule to the desired target orientation. Further, taking into account the D2 symmetry of a three-dimensionally aligned distribution, a symmetrized version of the measure is constructed that serves as a direct indicator of the degree of three-dimensional alignment of a distribution. The calculation of the rotational dynamics of iodobenzene under the influence of two cross-polarized laser pulses demonstrates the effectiveness of the proposed metric.
Three-dimensional particle cloud simulation based on illumination model
Xing, Yumeihui; Duan, Jin; Zhu, Yong; Wang, Hao
2017-11-01
The simulation of 3D clouds has been a challenging research question in the field of computer graphics. Aiming at the problem that the existing three-dimensional cloud is not realistic, a three-dimensional particle cloud simulation method based on the illumination model is proposed, which randomly generate the particles according to the principle of the particle system and give the particles the initial color, size and shape. And then add the lighting effects and render them to achieve the three-dimensional cloud simulation. Comparing with the previous three-dimensional cloud modeling method, this method has the advantages of rapid rendering of cloud, because of the effect of adding light, the real feeling more intense.
Mandibular asymmetry: a three-dimensional quantification of bilateral condyles
National Research Council Canada - National Science Library
Lin, Han; Zhu, Ping; Lin, Yi; Wan, Shuangquan; Shu, Xin; Xu, Yue; Zheng, Youhua
2013-01-01
.... In this study, a three-dimensional (3-D) quantification of bilateral asymmetrical condyles was firstly conducted to identify the specific role of 3-D condylar configuration for mandibular asymmetry...
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.
Three-dimensional transesophageal echocardiography of the atrial septal defects
Directory of Open Access Journals (Sweden)
Romero-Cárdenas Ángel
2008-07-01
Full Text Available Abstract Transesophageal echocardiography has advantages over transthoracic technique in defining morphology of atrial structures. Even though real time three-dimensional echocardiographic imaging is a reality, the off-line reconstruction technique usually allows to obtain higher spatial resolution images. The purpose of this study was to explore the accuracy of off-line three-dimensional transesophageal echocardiography in a spectrum of atrial septal defects by comparing them with representative anatomic specimens.
Three-dimensional transesophageal echocardiography of the atrial septal defects
Roldán, Francisco-Javier; Vargas-Barrón, Jesús; Vázquez-Antona, Clara; Castellanos, Luis Muñoz; Erdmenger-Orellana, Julio; Romero-Cárdenas, Ángel; Martínez-Ríos, Marco-Antonio
2008-01-01
Transesophageal echocardiography has advantages over transthoracic technique in defining morphology of atrial structures. Even though real time three-dimensional echocardiographic imaging is a reality, the off-line reconstruction technique usually allows to obtain higher spatial resolution images. The purpose of this study was to explore the accuracy of off-line three-dimensional transesophageal echocardiography in a spectrum of atrial septal defects by comparing them with representative anatomic specimens. PMID:18638394
National Research Council Canada - National Science Library
Kobayashi, Masahiro; Nakajima, Tatsuo; Mori, Ayako; Tanaka, Daigo; Fujino, Toyomi; Chiyokura, Hiroaki
2006-01-01
.... They must understand the three-dimensional (3D) structure of the lips. However, they may have difficulty learning the surgical procedures precisely from normal textbooks with two-dimensional illustrations...
DEFF Research Database (Denmark)
Arandiyan, Hamidreza; Scott, Jason; Wang, Yuan
2016-01-01
Newly designed 3D highly ordered macro/mesoporous multifunctional La1-xCexCoO3 nanohybrid frameworks with a 2D hexagonal mesostructure were fabricated via facile meso-molding in a three-dimensionally macroporous perovskite (MTMP) route. The nanohybrid framework exhibited excellent catalytic activ...
Two- and three-dimensional isogeometric cohesive elements for composite delamination analysis
Nguyen, Vinh-Phu; Kerfriden, Pierre; BORDAS, Stéphane
2014-01-01
We propose an automatic numerical method requiring minimal user intervention to simulate delamination in composite structures. We develop isogeometric cohesive elements for two- and three-dimensional delamination by exploiting the knot insertion algorithm directly from CAD data to generate cohesive elements along delamination. A complete computational framework is presented including pre-processing, processing and post-processing. They are explained in detail and implemented in MIGFEM - an op...
A plastic surgery application in evolution: three-dimensional printing.
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.
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 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...... of the welding machines. Simulations of the mechanical tests take into account material softening due to the accumulation of ductile damage and cover conventional tests, such as tensile–shear tests, cross-tension test and peel tests, as well as the possibility of special-purpose tests designed by the users...
Appearance of three dimensionality in wall-bounded MHD flows.
Klein, R; Pothérat, A
2010-01-22
We characterize experimentally how three dimensionality appears in wall-bounded magnetohydrodynamic flows. Our analysis of the breakdown of a square array of vortices in a cubic container singles out two mechanisms: first, a form of three dimensionality we call weak appears through differential rotation in individual 2D vortices. Second, strong three dimensionality characterized by vortex disruption leads on the one hand to a remarkable vortex array that is both steady and 3D, and, on the other hand, to scale-selective breakdown of two dimensionality in chaotic flows. Most importantly, these phenomena are entirely driven by inertia, so they are relevant to other flows with a tendency to two dimensionality, such as rotating, or stratified flows in geophysics and astrophysics.
Coupled particle dispersion by three-dimensional vortex structures
Energy Technology Data Exchange (ETDEWEB)
Troutt, T.R.; Chung, J.N.; Crowe, C.T.
1996-12-31
The primary objective of this research program is to obtain understanding concerning the role of three-dimensional vortex structures in the dispersion of particles and droplets in free shear flows. This research program builds on previous studies which focused on the nature of particle dispersion in large scale quasi two-dimensional vortex structures. This investigation employs time dependent experimental and numerical techniques to provide information concerning the particulate dispersion produced by three dimensional vortex structures in free shear layers. The free shear flows investigated include modified plane mixing layers, and modified plane wakes. The modifications to these flows involve slight perturbations to the initiation boundary conditions such that three-dimensional vortex structures are rapidly generated by the experimental and numerical flow fields. Recent results support the importance of these vortex structures in the particle dispersion process.
Three-dimensional network of Drosophila brain hemisphere
Mizutani, Ryuta; Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio
2016-01-01
The first step to understanding brain function is to determine the brain's network structure. We report a three-dimensional analysis of the brain network of the fruit fly Drosophila melanogaster by synchrotron-radiation tomographic microscopy. A skeletonized wire model of the left half of the brain network was built by tracing the three-dimensional distribution of X-ray absorption coefficients. The obtained models of neuronal processes were classified into groups on the basis of their three-dimensional structures. These classified groups correspond to neuronal tracts that send long-range projections or repeated structures of the optic lobe. The skeletonized model is also composed of neuronal processes that could not be classified into the groups. The distribution of these unclassified structures correlates with the distribution of contacts between neuronal processes. This suggests that neurons that cannot be classified into typical structures should play important roles in brain functions. The quantitative de...
On three-dimensional quiver gauge theories of type B
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.
Radiation hardness of three-dimensional polycrystalline diamond detectors
Energy Technology Data Exchange (ETDEWEB)
Lagomarsino, Stefano, E-mail: lagomarsino@fi.infn.it; Sciortino, Silvio [National Institute of Nuclear Physics (INFN), Via B. Rossi, 1-3, 50019 Sesto Fiorentino (Italy); Department of Physics and Astronomy, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Bellini, Marco [European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Istituto Nazionale di Ottica (INO-CNR), Largo Enrico Fermi 6, 50125 Firenze (Italy); Corsi, Chiara [Department of Physics and Astronomy, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino (Italy); European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Cindro, Vladimir [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Kanxheri, Keida; Servoli, Leonello [National Institute of Nuclear Physics (INFN), Via A. Pascoli, 06123 Perugia (Italy); Department of Physics, University of Perugia, Via A. Pascoli, 06123 Perugia (Italy); Morozzi, Arianna [Department of Engineering, University of Perugia, Via G. Duranti 93, 06125 Perugia (Italy); Passeri, Daniele [National Institute of Nuclear Physics (INFN), Via A. Pascoli, 06123 Perugia (Italy); Department of Engineering, University of Perugia, Via G. Duranti 93, 06125 Perugia (Italy); Schmidt, Christian J. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt (Germany)
2015-05-11
The three-dimensional concept in particle detection is based on the fabrication of columnar electrodes perpendicular to the surface of a solid state radiation sensor. It permits to improve the radiation resistance characteristics of a material by lowering the necessary bias voltage and shortening the charge carrier path inside the material. If applied to a long-recognized exceptionally radiation-hard material like diamond, this concept promises to pave the way to the realization of detectors of unprecedented performances. We fabricated conventional and three-dimensional polycrystalline diamond detectors, and tested them before and after neutron damage up to 1.2 ×10{sup 16 }cm{sup −2}, 1 MeV-equivalent neutron fluence. We found that the signal collected by the three-dimensional detectors is up to three times higher than that of the conventional planar ones, at the highest neutron damage ever experimented.
Three-dimensional, three-component wall-PIV
Energy Technology Data Exchange (ETDEWEB)
Berthe, Andre; Christensen, Carolyn; Goubergrits, Leonid; Affeld, Klaus; Kertzscher, Ulrich [Charite - Universitaetsmedizin Berlin, Biofluid Mechanics Laboratory, Berlin (Germany); Kondermann, Daniel; Garbe, Christoph [University of Heidelberg, Digital Image Processing Research Group, Heidelberg Collaboratory for Image Processing, Heidelberg (Germany)
2010-06-15
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. (orig.)
Three Dimensional Analysis of Elastic Rocket and Launcher at Launching
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.
Three dimensional least-squares fitting of ellipsoids and hyperboloids
Rahmadiantri, Elvira; Putri Lawiyuniarti, Made; Muchtadi-Alamsyah, Intan; Rachmaputri, Gantina
2017-09-01
Spatial continuity can be described as a variogram model that has an ellipsoid anisotropy. In previous research, two-dimensional least-square ellipse fitting method by Fitzgibbon, Pilu and Fisher has been applied to the analysis of spatial continuity for coal deposits. However, it is not easy to generalize their method to three-dimensional least-square ellipsoid fitting. In this research, we obtain a three-dimensional least-square fitting for ellipsoids and hyperboloids by generalizing two-dimensional least-square ellipse fitting method introduced by Gander, Golub and Strebel.
Three-dimensional analysis of partially open butterfly valve flows
Energy Technology Data Exchange (ETDEWEB)
Huang, C.; Kim, R.H. [Univ. of North Carolina, Charlotte, NC (United States). Dept. of Mechanical Engineering and Engineering Science
1996-09-01
A numerical simulation of butterfly valve flows is a useful technique to investigate the physical phenomena of the flow field. A three-dimensional numerical analysis was carried out on incompressible fluid flows in a butterfly valve by using FLUENT, which solves difference equations. Characteristics of the butterfly valve flows at different valve disk angles with a uniform incoming velocity were investigated. Comparisons of FLUENT results with other results, i.e., experimental results, were made to determine the accuracy of the employed method. Results of the three-dimensional analysis may be useful in the valve design.
A method for computing three-dimensional turbulent flows
Bernard, P. S.; Berger, B. S.
1982-06-01
The MVC (mean vorticity and covariance) turbulence closure is derived for three-dimensional turbulent flows. The derivation utilizes Lagrangian time expansion techniques applied to the unclosed terms of the mean vorticity and covariance equations. The closed mean vorticity equation is applied to the numerical solution of fully developed three-dimensional channel flow. Anisotropies in the wall region are modelled by pairs of counterrotating streamwise vortices. The numerical results are in close agreement with experimental data. Analysis of the contributions of the terms in the mean vorticity equation gives insight into the dynamics of the turbulent boundary layer.
Three-dimensional theory for light-matter interaction
DEFF Research Database (Denmark)
Sørensen, Martin Westring; Sørensen, Anders Søndberg
2008-01-01
We present a full quantum mechanical three dimensional theory describing an electromagnetic field interacting with an ensemble of identical atoms. The theory is constructed such that it describes recent experiments on light-matter quantum interfaces, where the quantum fluctuations of light...... fluctuations are mapped between atoms and light while the random positioning of the atoms give rise to decay due to spontaneous emission. Furthermore we identify limits, where the full three dimensional theory reduce to the one dimensional theory typically used to describe the interaction....
Three-dimensional telegrapher's equation and its fractional generalization.
Masoliver, Jaume
2017-08-01
We derive the three-dimensional telegrapher's equation out of a random walk model. The model is a three-dimensional version of the multistate random walk where the number of different states form a continuum representing the spatial directions that the walker can take. We set the general equations and solve them for isotropic and uniform walks which finally allows us to obtain the telegrapher's equation in three dimensions. We generalize the isotropic model and the telegrapher's equation to include fractional anomalous transport in three dimensions.
Bootstrapping Critical Ising Model on Three Dimensional Real Projective Space.
Nakayama, Yu
2016-04-08
Given conformal data on a flat Euclidean space, we use crosscap conformal bootstrap equations to numerically solve the Lee-Yang model as well as the critical Ising model on a three dimensional real projective space. We check the rapid convergence of our bootstrap program in two dimensions from the exact solutions available. Based on the comparison, we estimate that our systematic error on the numerically solved one-point functions of the critical Ising model on a three dimensional real projective space is less than 1%. Our method opens up a novel way to solve conformal field theories on nontrivial geometries.
Surface plasmon of three-dimensional Dirac semimetals.
Bonacic Losic, Zeljana
2017-12-08
The surface plasmon excitation spectrum is calculated for the semi-infinite three-dimensional Dirac semimetal. We used the random phase approximation (RPA) for the calculation of the surface dielectric function, from which we derived the dynamical structure factor. The surface excitation spectrum shows a well-defined strong surface plasmon peak due to the plasmon mode in the bulk, with a noticeable influence of electron-hole excitations at large wave vectors parallel to the surface. The obtained spectrum will be useful for exploring experimentally the surface spectral properties of three-dimensional topological Dirac semimetals. © 2017 IOP Publishing Ltd.
Weyl and Dirac semimetals in three-dimensional solids
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.
Three-dimensional microtomographic imaging of human brain cortex
Mizutania, Ryuta; Uesugi, Kentaro; Ohyama, Masami; Takekoshi, Susumu; Osamura, R Yoshiyuki; Suzuki, Yoshio
2016-01-01
This paper describes an x-ray microtomographic technique for imaging the three-dimensional structure of the human cerebral cortex. Neurons in the brain constitute a neural circuit as a three-dimensional network. The brain tissue is composed of light elements that give little contrast in a hard x-ray transmission image. The contrast was enhanced by staining neural cells with metal compounds. The obtained structure revealed the microarchitecture of the gray and white matter regions of the frontal cortex, which is responsible for the higher brain functions.
Three-dimensional telegrapher's equation and its fractional generalization
Masoliver, Jaume
2017-08-01
We derive the three-dimensional telegrapher's equation out of a random walk model. The model is a three-dimensional version of the multistate random walk where the number of different states form a continuum representing the spatial directions that the walker can take. We set the general equations and solve them for isotropic and uniform walks which finally allows us to obtain the telegrapher's equation in three dimensions. We generalize the isotropic model and the telegrapher's equation to include fractional anomalous transport in three dimensions.
Bootstrapping the Three-Dimensional Supersymmetric Ising Model
Bobev, Nikolay; Mazac, Dalimil; Paulos, Miguel F
2015-01-01
We implement the conformal bootstrap program for three-dimensional CFTs with $\\mathcal{N}=2$ supersymmetry and find universal constraints on the spectrum of operator dimensions in these theories. By studying the bounds on the dimension of the first scalar appearing in the OPE of a chiral and an anti-chiral primary, we find a kink at the expected location of the critical three-dimensional $\\mathcal{N}=2$ Wess-Zumino model, which can be thought of as a supersymmetric analog of the critical Ising model. Focusing on this kink, we determine, to high accuracy, the low-lying spectrum of operator dimensions of the theory.
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......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...
Micro-fabrication of three dimensional pyrolysed carbon microelectrodes
DEFF Research Database (Denmark)
2017-01-01
The present invention relates in one aspect to a method of producing a three-dimensional microscale patterned resist template for a pyrolysed carbon microelectrode structure by means of UV-lithography. Coating a planar substrate with an epoxy-based negative photoresist, such as an SU-8 photoresist...... is characterized by a soft baking temperature below 70 °C. Repetitive coating and partial depth exposure allows for the fabrication of multiple level laterally interconnected structures. Carbonization of the resist template provides truly three-dimensional carbon microelectrode structures....
Bayesian approach for three-dimensional aquifer characterization at the Hanford 300 Area
Murakami, H.; Chen, X.; Hahn, M. S.; Liu, Y.; Rockhold, M. L.; Vermeul, V. R.; Zachara, J. M.; Rubin, Y.
2010-10-01
This study presents a stochastic, three-dimensional characterization of a heterogeneous hydraulic conductivity field within the Hanford 300 Area, Washington, USA, by assimilating large-scale, constant-rate injection test data with small-scale, three-dimensional electromagnetic borehole flowmeter (EBF) measurement data. We first inverted the injection test data to estimate the transmissivity field, using zeroth-order temporal moments of pressure buildup curves. We applied a newly developed Bayesian geostatistical inversion framework, the method of anchored distributions (MAD), to obtain a joint posterior distribution of geostatistical parameters and local log-transmissivities at multiple locations. The unique aspects of MAD that make it suitable for this purpose are its ability to integrate multi-scale, multi-type data within a Bayesian framework and to compute a nonparametric posterior distribution. After we combined the distribution of transmissivities with depth-discrete relative-conductivity profile from the EBF data, we inferred the three-dimensional geostatistical parameters of the log-conductivity field, using the Bayesian model-based geostatistics. Such consistent use of the Bayesian approach throughout the procedure enabled us to systematically incorporate data uncertainty into the final posterior distribution. The method was tested in a synthetic study and validated using the actual data that was not part of the estimation. Results showed broader and skewed posterior distributions of geostatistical parameters except for the mean, which suggests the importance of inferring the entire distribution to quantify the parameter uncertainty.
Bayesian approach for three-dimensional aquifer characterization at the Hanford 300 Area
Directory of Open Access Journals (Sweden)
H. Murakami
2010-10-01
Full Text Available This study presents a stochastic, three-dimensional characterization of a heterogeneous hydraulic conductivity field within the Hanford 300 Area, Washington, USA, by assimilating large-scale, constant-rate injection test data with small-scale, three-dimensional electromagnetic borehole flowmeter (EBF measurement data. We first inverted the injection test data to estimate the transmissivity field, using zeroth-order temporal moments of pressure buildup curves. We applied a newly developed Bayesian geostatistical inversion framework, the method of anchored distributions (MAD, to obtain a joint posterior distribution of geostatistical parameters and local log-transmissivities at multiple locations. The unique aspects of MAD that make it suitable for this purpose are its ability to integrate multi-scale, multi-type data within a Bayesian framework and to compute a nonparametric posterior distribution. After we combined the distribution of transmissivities with depth-discrete relative-conductivity profile from the EBF data, we inferred the three-dimensional geostatistical parameters of the log-conductivity field, using the Bayesian model-based geostatistics. Such consistent use of the Bayesian approach throughout the procedure enabled us to systematically incorporate data uncertainty into the final posterior distribution. The method was tested in a synthetic study and validated using the actual data that was not part of the estimation. Results showed broader and skewed posterior distributions of geostatistical parameters except for the mean, which suggests the importance of inferring the entire distribution to quantify the parameter uncertainty.
Rapid Creation of Three-Dimensional, Tactile Models from Crystallographic Data
Directory of Open Access Journals (Sweden)
Nathan B. Fisher
2016-01-01
Full Text Available A method for the conversion of crystallographic information framework (CIF files to stereo lithographic data files suitable for printing on three-dimensional printers is presented. Crystallographic information framework or CIF files are capable of being manipulated in virtual space by a variety of computer programs, but their visual representations are limited to the two-dimensional surface of the computer screen. Tactile molecular models that demonstrate critical ideas, such as symmetry elements, play a critical role in enabling new students to fully visualize crystallographic concepts. In the past five years, major developments in three-dimensional printing has lowered the cost and complexity of these systems to a level where three-dimensional molecular models may be easily created provided that the data exists in a suitable format. Herein a method is described for the conversion of CIF file data using existing free software that allows for the rapid creation of inexpensive molecular models. This approach has numerous potential applications in basic research, education, visualization, and crystallography.
Parsani, Matteo; Carpenter, Mark H.; Nielsen, Eric J.
2015-01-01
Non-linear entropy stability and a summation-by-parts framework are used to derive entropy stable wall boundary conditions for the three-dimensional compressible Navier-Stokes equations. A semi-discrete entropy estimate for the entire domain is achieved when the new boundary conditions are coupled with an entropy stable discrete interior operator. The data at the boundary are weakly imposed using a penalty flux approach and a simultaneous-approximation-term penalty technique. Although discontinuous spectral collocation operators on unstructured grids are used herein for the purpose of demonstrating their robustness and efficacy, the new boundary conditions are compatible with any diagonal norm summation-by-parts spatial operator, including finite element, finite difference, finite volume, discontinuous Galerkin, and flux reconstruction/correction procedure via reconstruction schemes. The proposed boundary treatment is tested for three-dimensional subsonic and supersonic flows. The numerical computations corroborate the non-linear stability (entropy stability) and accuracy of the boundary conditions.
Three-dimensional Modelling Technology for City Indoor Positioning and Navigation Applications
Zhang, Xin; Chen, Yongxin; Wang, Weisheng
2016-11-01
For city indoor positioning and navigation applications, there are two technical problems should be solved, which are the modelling efficiency and the validity and accuracy of the spatial models. In this paper, the quick modelling technology is introduced which uses the multi-angle remote sensing based on the unmanned aerial vehicle measurement. To enhance the validity and accuracy of the spatial models, we proposed an algorithm to remove the line style and planar style foreground occlusions before reconstructing backgrounds. The three-dimensional models can only provide the spatial framework for the city indoor positioning. Furthermore, the simple indoor three-dimensional modelling technology which is based on the building design drawings. In the end, the application in the public safety emergency rescue is introduced.
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...
New advances in three dimensional transient electromagnetic inversion
Energy Technology Data Exchange (ETDEWEB)
Newman, Gregory A.; Commer, Michael
2004-06-16
Inversion of transient electromagnetic (TEM) data sets to image the subsurface three-dimensional (3-D) electrical conductivity and magnetic permeability properties can be done directly in the time domain. The technique, first introduced by Wang et al. (1994) for causal and diffusive electromagnetic fields and subsequently implemented by Zhdanov and Portniaguine (1997) in the framework of iterative migration, is based upon imaging methods originally developed for seismic wavefields (Claerbout, 1971; Tarantola, 1984). In this paper we advance the original derivations of Wang et al. (1994) and Zhdanov and Portniaguine (1997) to treat non-causal TEM fields, as well as correct a flaw in the theory for treatment of magnetic field data. Our 3D imaging scheme is based on a conjugate-gradient search for the minimum of an error functional involving EM measurements governed by Maxwell's equations without displacement currents. Treatment for magnetic field, voltage (time derivative of the magnetic field) and electric field data are given. The functional can be computed by propagating the data errors back into the model in reverse time along with a DC field, sourced by the integrated data errors over the measurement time range. By correlating these fields, including the time-integrated back-propagated fields, with the corresponding incident field and its initial value at each image point, efficient computational forms for the gradients are developed. The forms of the gradients allow for additional efficiencies when voltage and electric field data are inverted. In such instances the combined data errors can be back-propagated jointly, significantly reducing the computation time required to solve the inverse problem. The inversion algorithm is applied to the long offset transient electromagnetic measurement (LOTEM) configuration thereby demonstrating its capability in inverting non-causal field measurements of electric field and voltage, sourced by a grounded wire, over
Three dimensional Lagrangian structures in the Antarctic Polar Vortex.
Mancho, Ana M.; Garcia-Garrido, Victor J.; Curbelo, Jezabel; Niang, Coumba; Mechoso, Carlos R.; Wiggins, Stephen
2017-04-01
. M. Mancho, A. M. A theoretical framework for lagrangian descriptors. International Journal of Bifurcation and Chaos (2017) to appear. [5] The three-dimensional Lagrangian geometry of the Antarctic Polar Vortex circulation. Preprint.
Evaluation of three-dimensional virtual perception of garments
Aydoğdu, G.; Yeşilpinar, S.; Erdem, D.
2017-10-01
In recent years, three-dimensional design, dressing and simulation programs came into prominence in the textile industry. By these programs, the need to produce clothing samples for every design in design process has been eliminated. Clothing fit, design, pattern, fabric and accessory details and fabric drape features can be evaluated easily. Also, body size of virtual mannequin can be adjusted so more realistic simulations can be created. Moreover, three-dimensional virtual garment images created by these programs can be used while presenting the product to end-user instead of two-dimensional photograph images. In this study, a survey was carried out to investigate the visual perception of consumers. The survey was conducted for three different garment types, separately. Questions about gender, profession etc. was asked to the participants and expected them to compare real samples and artworks or three-dimensional virtual images of garments. When survey results were analyzed statistically, it is seen that demographic situation of participants does not affect visual perception and three-dimensional virtual garment images reflect the real sample characteristics better than artworks for each garment type. Also, it is reported that there is no perception difference depending on garment type between t-shirt, sweatshirt and tracksuit bottom.
Magnetic relaxation in a three-dimensional ferromagnet with weak ...
Indian Academy of Sciences (India)
... determined previously for the same sample from static critical phenomena measurements) for a nearly ordered intermetallic compound Ni3Al, which is an experimental realization of a three-dimensional (= 3) ferromagnet with weak quenched random-exchange disorder. None of the functional forms of r() predicted by ...
Three-dimensional geostatistical modeling of soil organic carbon
Brus, D.J.; Yang, Ren Min; Zhang, Gan Lin
2016-01-01
For mapping soil properties in three dimensions the simplest option is to choose a series of depth intervals, and to calibrate a two-dimensional (2-D) model for each interval. The alternative is to calibrate a full three dimensional (3-D) model that describes the variation in lateral and vertical
Flux penetrations into two- and three-dimensional nanostructured superconductors
Energy Technology Data Exchange (ETDEWEB)
Tamegai, T., E-mail: tamegai@ap.t.u-tokyo.ac.jp [Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Tsuchiya, Y.; Tada, S.; Ibuka, J.; Mine, A.; Pyon, S. [Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Mawatari, Y.; Nagasawa, S.; Hidaka, M.; Maezawa, M. [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan)
2014-08-15
Highlights: • Flux penetrations into two- and three-dimensional nanostructured superconductors are observed by magneto-optical imaging. • In two-dimensional superconducting networks with square holes on square lattice, anomalous diagonal penetrations are observed. • In three-dimensional superconducting shifted strip arrays, various forms of vortex avalanches are observed. - Abstract: We have fabricated two- and three-dimensional nanostructured superconductors, and observed vortex penetrations by magneto-optical imaging. In the case of two-dimensional superconducting networks with square holes on a square lattice, anomalous diagonal penetrations are widely observed. Two kinds of diagonal vortex penetrations at high and low temperatures have been interpreted as originating from the repulsive interaction of vortices and sharp fan-shaped vortex penetration from the corners of the square holes, respectively. In the case of three-dimensional stack of superconducting strip arrays with double and triple layers, vortex avalanches have been observed in a wide temperature and dimension ranges due to enhanced demagnetization effect. While spotlike avalanches are observed when the overlap of strips is small, anomalous linear avalanches traversing many strips in different layers are observed when the overlap is large. In triple-layer strip arrays, in addition to the spotlike and linear avalanches, vortex penetrations along the line of strips are also observed. Origins of the anomalous diagonal penetration and vortex avalanches are discussed.
Three-dimensional analysis of condylar hyperplasia with computed tomography.
Mutoh, Y; Ohashi, Y; Uchiyama, N; Terada, K; Hanada, K; Sasaki, F
1991-02-01
Three-dimensional surface reconstruction imaging from CT scans was used to study the deformity of the mandible in six patients with mandibular asymmetry. High-resolution axial CT scans of the mandible were obtained using Somatom-DR3 (Siemens). COSMOZONE-2SA (Nikon) with PC-9801VX21 (NEC) was used to reconstruct the three-dimensional images. The six patients were divided into two groups. One group was classified as unilateral hybrid forms and the other group was classified hemimandibular elongation on the diagnostic criteria of Obwegeser and Makek (1986). In the three-dimensional surface reconstruction, exact location and the degree of the deformity in the region from the ascending ramus to the condylar head and the lingual aspect from the ascending ramus to the mandibular body were accurately represented. In addition, the three-dimensional images could be easily rotated arbitrarily, precise evaluation could be done at every part of the mandible. On diagnosis, the mandibular morphology classified into the unilateral hybrid forms was presumed to vary from case to case even in the same classification.
Exploring Approaches to Teaching in Three-Dimensional Virtual Worlds
Englund, Claire
2017-01-01
Purpose: The purpose of this paper is to explore how teachers' approaches to teaching and conceptions of teaching and learning with educational technology influence the implementation of three-dimensional virtual worlds (3DVWs) in health care education. Design/methodology/approach: Data were collected through thematic interviews with eight…
Toward a comparative analysis of three-dimensional shape measures
Power, Gregory J.; Gregga, Jason B.
2002-02-01
Measuring a system's capability to acquire accurate three- dimensional shape is important for validating the system for a particular application. Various system factors are reviewed that contribute to inaccurate shape. As shown in this paper, different shape measures do not do a complete evaluation but provide different information depending on the type of error. A partial-directed hausdorf (PDH) and complex inner product (CIP) measure that were previously introduced to measure two-dimensional shapes are now extended to measure three-dimensional shapes. PDH measures how close the 3D surface is to the ideal 3D surface within a predefined acceptable error margin, while the CIP measures how well the 3D surface correlates to the ideal 3D surface. Two variants of the CIP measure are used in this paper including a pure phase only filter and a normalized matched filter. The CIP measure is compared to the Procrustes metric for comparing shapes. Using a test case shape, the measures are compared and shown to provide varying information. Alone, any one measure cannot provide complete shape information. Combining measures provides a more robust three-dimensional shape measurement system. The shape measures are demonstrated first on three-dimensional data with controlled variation and then on laser ranging data.
hp Spectral element methods for three dimensional elliptic problems ...
Indian Academy of Sciences (India)
Abstract. This is the first of a series of papers devoted to the study of h-p spec- tral element methods for solving three dimensional elliptic boundary value problems on non-smooth domains using parallel computers. In three dimensions there are three different types of singularities namely; the vertex, the edge and the ...
Three dimensional rigorous model for optical scattering problems
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
Wave packet construction in three-dimensional quantum billiards ...
Indian Academy of Sciences (India)
as the symmetry breaks due to commensurate or incommensurate ratio of sides. 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.
Wave packet construction in three-dimensional quantum billiards ...
Indian Academy of Sciences (India)
Wave packet construction in three-dimensional quantum billiards: Visualizing the closed orbit, collapse and revival of wave packets in the cubical billiard ... billiard and these levels disappear completely or partially for a parallelepiped billiard as the symmetry breaks due to commensurate or incommensurate ratio of sides.
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, ...
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...
Polyimide Aerogels with Three-Dimensional Cross-Linked Structure
Meador, Mary Ann B. (Inventor)
2016-01-01
A method for creating a three dimensional cross-linked polyimide structure includes dissolving a diamine, a dianhydride, and a triamine in a solvent, imidizing a polyamic acid gel by heating the gel, extracting the gel in a second solvent, supercritically drying the gel, and removing the solvent to create a polyimide aerogel.
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 ...
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 ...
KP Equation in a Three-Dimensional Unmagnetized Warm Dusty ...
Indian Academy of Sciences (India)
Kh. H. El-Shorbagy
2017-11-27
Nov 27, 2017 ... Abstract. In this work, we investigate the propagation of three-dimensional nonlinear dust-acoustic and dust-. Coulomb waves in an unmagnetized warm dusty plasma consisting of electrons, ions, and charged dust particles. The grain charge fluctuation is incorporated through the current balance equation.
h-p Spectral element methods for three dimensional elliptic ...
Indian Academy of Sciences (India)
The h-p version of the finite element method for solving three dimensional elliptic problems on non-smooth domains with exponential accuracy was proposed by Guo in [9,. 12]. To overcome the singularities which arise along vertices and edges they used geo- metric meshes which are defined in neighbourhoods of vertices, ...
Three-dimensional reacting shock–bubble interaction
Diegelmann, Felix; Hickel, S.; Adams, Nikolaus A.
2017-01-01
We investigate a reacting shock–bubble interaction through three-dimensional numerical simulations with detailed chemistry. The convex shape of the bubble focuses the shock and generates regions of high pressure and temperature, which are sufficient to ignite the diluted stoichiometric
The measure in three dimensional Nambu-Goto string theory
Ambjorn, J.; Sedrakyan, A.
1996-01-01
We show that the measure of the three dimensional Nambu-Goto string theory has a simple decomposition as a measure on two parameter group of induced area-preserving transformations of the immersed surface and a trivial measure for the area of the surface.
Three-dimensional echocardiographic assessment of the repaired mitral valve.
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.
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...
Kondo effect in three-dimensional Dirac and Weyl systems
Mitchell, Andrew K.; Fritz, Lars|info:eu-repo/dai/nl/371569559
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
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.
Robust cylinder fitting in three-dimensional point cloud data
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
Three-dimensional shallow water system: A relaxation approach
Liu, Xin; Mohammadian, Abdolmajid; Infante Sedano, Julio Ángel; Kurganov, Alexander
2017-03-01
We study a three-dimensional shallow water system, which is obtained from the three-dimensional Navier-Stokes equations after Reynolds averaging and under the simplifying hydrostatic pressure assumption. Since the three-dimensional shallow water system is generically not hyperbolic, it cannot be numerically solved using hyperbolic shock capturing schemes. At the same time, existing simple finite-difference and finite-volume methods may fail in simulations of unsteady flows with sharp gradients, such as dam-break and flood flows. To overcome this limitation, we propose a novel numerical method, which is based on a relaxation approach utilized to ;hyperbolize; the three-dimensional shallow water system. The extended relaxation system is hyperbolic and we develop a second-order semi-discrete central-upwind scheme for it. The proposed numerical method can preserve ;lake at rest; steady states and positivity of water depth over irregular bottom topography. The accuracy, stability and robustness of the developed numerical method is verified on five numerical experiments.
Optimal eavesdropping in cryptography with three-dimensional quantum states.
Bruss, D; Macchiavello, C
2002-03-25
We study optimal eavesdropping in quantum cryptography with three-dimensional systems, and show that this scheme is more secure against symmetric attacks than protocols using two-dimensional states. We generalize the according eavesdropping transformation to arbitrary dimensions, and discuss the connection with optimal quantum cloning.
Three-dimensional topology optimized electrically-small conformal antenna
DEFF Research Database (Denmark)
Erentok, Aycan; Sigmund, Ole
2008-01-01
A three-dimensional (3D) conductor-based conformal electrically small antenna is obtained using a topology optimization method. The optimization method distributes a certain amount of conductive material to a designated design domain such that the material layout defines an electrically small...
Three-Dimensional Printing Using a Photoinitiated Polymer
Muskin, Joseph; Ragusa, Matthew; Gelsthorpe, Thomas
2010-01-01
Printers capable of producing three-dimensional objects are becoming more common. Most of these printers are impractical for use in the chemistry classroom because of the expense incurred in fabricating a print head that must be controlled in three dimensions. We propose a simpler solution to this problem that allows the emerging technology of…
Three-dimensional analysis of abnormal ultrastructural alteration in ...
Indian Academy of Sciences (India)
The deterioration of subcellular organelles, including the mitochondria, is another major ultrastructural characteristic of AD pathogenesis, in addition to amyloid plaque deposition. However, the three-dimensional (3-D) study of mitochondrial structural alteration in AD remains poorly understood. Therefore, ultrastructural ...
Three-Dimensional Densitometric Reconstruction and Visualization of Stenosed
van den Broek, J.G.M.; Slump, Cornelis H.; Storm, C.J.; van Benthem, A.C.; Buis, B.
1995-01-01
In this paper we report results from an ongoing study about the diagnostic benefits of three-dimensional (3D) visualization and quantification of stenosed coronary artery segments. Biplane angiographic images do not provide enough information for the exact reconstruction of the coronary arteries.
Three-Dimensional Stiffness of the Carpal Arch
Gabra, Joseph N.; Li, Zong-Ming
2015-01-01
The carpal arch of the wrist is formed by irregularly shaped carpal bones interconnected by numerous ligaments, resulting in complex structural mechanics. The purpose of this study was to determine the three-dimensional stiffness characteristics of the carpal arch using displacement perturbations. It was hypothesized that the carpal arch would exhibit an anisotropic stiffness behavior with principal directions that are oblique to the conventional anatomical axes. Eight (n = 8) cadavers were used in this study. For each specimen, the hamate was fixed to a custom stationary apparatus. An instrumented robot arm applied three-dimensional displacement perturbations to the ridge of trapezium and corresponding reaction forces were collected. The displacement-force data were used to determine a three-dimensional stiffness matrix using least squares fitting. Eigendecomposition of the stiffness matrix was used to identify the magnitudes and directions of the principal stiffness components. The carpal arch structure exhibited anisotropic stiffness behaviors with a maximum principal stiffness of 16.4 ± 4.6 N/mm that was significantly larger than the other principal components of 3.1 ± 0.9 and 2.6 ± 0.5 N/mm (p articulation between the trapezium and scaphoid. This study provides advanced characterization of the wrist's three-dimensional structural stiffness for improved insight into wrist biomechanics, stability, and function. PMID:26617368
Singularities at rims in three-dimensional fluid flow
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
Three-Dimensional Extension of a Digital Library Service System
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…
Three-dimensional free vibration analysis of thick laminated circular ...
African Journals Online (AJOL)
Three-dimensional free vibration analysis of thick laminated circular plates. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to print, save, and work with PDFs, ...
A Three-Dimensional Receiver Operator Characteristic Surface Diagnostic Metric
2010-10-01
Annual Conference of the Prognostics and Health Management Society, 2010 1 A Three-Dimensional Receiver Operator Characteristic Surface... Characteristic (ROC) curves are commonly applied as metrics for quantifying the performance of binary fault detection systems. An ROC curve provides a...receiver operator characteristic (3D ROC) surface metric has been developed. This is done by generating and applying two separate curves: the
Three-dimensional simulation of laser–plasma-based electron ...
Indian Academy of Sciences (India)
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 to assess ...
Three-dimensional musculoskeletal modelling of the seated row ...
African Journals Online (AJOL)
Objective. To evaluate whether three-dimensional (3D) musculoskeletal modelling could be effective in assessing the safety and efficacy of exercising on a seated row resistance-training machine. The focus of the evaluation was on biomechanical and anthropometric considerations of the end user. Methods. Three ...
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...
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...
Analysis of three-dimensional transient seepage into ditch drains ...
Indian Academy of Sciences (India)
-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 heights in ...
Two- and three-dimensional blade vortex interactions
Davoudzadeh, F.; Liu, N.-S; Briley, W. R.; Buggeln, R. C.; Shamroth, S. J.
1990-01-01
A three-dimensional time dependent Navier-Stokes analysis was applied to the rotor blade vortex interaction (BVI) problem. The numerical procedure is an iterative implicit procedure using three point central differences to represent spatial derivatives. A series of calculations were made to determine the time steps, pseudo-time steps, iterations, artificial dissipation level, etc. required to maintain a nondissipative vortex. Results show the chosen method to have excellent non-dissipative properties provided the correct parameters are chosen. This study was used to set parameters for both two- and three-dimensional blade vortex interaction studies. The two-dimensional study considered the interaction between a vortex and a NACA0012 airfoil. The results showed the detailed physics during the interaction including the pressure pulse propagating from the blade. The simulated flow physics was qualitatively similar to that experimentally observed. The 2-D BVI phenomena is the result of the buildup and violent collapse of the shock waves and local supersonic pockets on the blade surfaces. The resulting pressure pulse build-up appears to be centered at the blade leading edge. The three-dimensional interaction study considered the case of a vortex at 20 deg incidence to the blade leading edge. Although the qualitative results were similar to that of the two-dimensional interaction, details clearly showed the three-dimensional nature of the interaction process.
Molecular dynamics study of two- and three-dimensional classical ...
Indian Academy of Sciences (India)
We have carried out a molecular dynamics simulation of two- and three- dimensional double Yukawa ... potential have been studied by employing the techniques of molecular dynamics simulations [6,7]. Since, with .... position vectors r(t) and velocity vectors v(t) were stored at every 10th time step for subsequent analysis.
Polycrystalline diamond detectors with three-dimensional electrodes
Energy Technology Data Exchange (ETDEWEB)
Lagomarsino, S., E-mail: lagomarsino@fi.infn.it [University of Florence, Department of Physics, Via Sansone 1, 50019 Sesto Fiorentino (Italy); INFN Firenze, Via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Bellini, M. [INO-CNR Firenze, Largo E. Fermi 6, 50125 Firenze (Italy); Brianzi, M. [INFN Firenze, Via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Carzino, R. [Smart Materials-Nanophysics, Istituto Italiano di Tecnologia, Genova, Via Morego 30, 16163 Genova (Italy); Cindro, V. [Joseph Stefan Institute, Jamova Cesta 39, 1000 Ljubljana (Slovenia); Corsi, C. [University of Florence, Department of Physics, Via Sansone 1, 50019 Sesto Fiorentino (Italy); LENS Firenze, Via N. Carrara 1, 50019 Sesto Fiorentino (Italy); Morozzi, A.; Passeri, D. [INFN Perugia, Perugia (Italy); Università degli Studi di Perugia, Dipartimento di Ingegneria, via G. Duranti 93, 06125 Perugia (Italy); Sciortino, S. [University of Florence, Department of Physics, Via Sansone 1, 50019 Sesto Fiorentino (Italy); INFN Firenze, Via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Servoli, L. [INFN Perugia, Perugia (Italy)
2015-10-01
The three-dimensional concept in diamond detectors has been applied, so far, to high quality single-crystal material, in order to test this technology in the best available conditions. However, its application to polycrystalline chemical vapor deposited diamond could be desirable for two reasons: first, the short inter-electrode distance of three-dimensional detectors should improve the intrinsically lower collection efficiency of polycrystalline diamond, and second, at high levels of radiation damage the performances of the poly-crystal material are not expected to be much lower than those of the single crystal one. We report on the fabrication and test of three-dimensional polycrystalline diamond detectors with several inter-electrode distances, and we demonstrate that their collection efficiency is equal or higher than that obtained with conventional planar detectors fabricated with the same material. - Highlights: • Pulsed laser fabrication of polycristalline diamond detectors with 3D electrodes. • Measurement of the charge collection efficiency (CCE) under beta irradiation. • Comparation between the CCE of 3D and conventional planar diamond sensors. • A rationale for the behavior of three-dimensional and planar sensors is given.
Three-dimensional computer modeling of slag cement hydration
Chen, Wei; Brouwers, Jos; Shui, Z.H.
2007-01-01
A newly developed version of a three-dimensional computer model for simulating the hydration and microstructure development of slag cement pastes is presented in this study. It is based on a 3-D computer model for Portland cement hydration (CEMHYD3D) which was originally developed at NIST, taken
Three dimensional geometric modeling of processing-tomatoes
Characterizing tomato geometries with different shapes and sizes would facilitate the design of tomato processing equipments and promote computer-based engineering simulations. This research sought to develop a three-dimensional geometric model that can describe the morphological attributes of proce...
Fu, Wei; Nijhoff, Frank W
2017-07-01
A unified framework is presented for the solution structure of three-dimensional discrete integrable systems, including the lattice AKP, BKP and CKP equations. This is done through the so-called direct linearizing transform, which establishes a general class of integral transforms between solutions. As a particular application, novel soliton-type solutions for the lattice CKP equation are obtained.
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.
Towards effective interactive three-dimensional colour postprocessing
Bailey, B. C.; Hajjar, J. F.; Abel, J. F.
1986-01-01
Recommendations for the development of effective three-dimensional, graphical color postprocessing are made. First, the evaluation of large, complex numerical models demands that a postprocessor be highly interactive. A menu of available functions should be provided and these operations should be performed quickly so that a sense of continuity and spontaneity exists during the post-processing session. Second, an agenda for three-dimensional color postprocessing is proposed. A postprocessor must be versatile with respect to application and basic algorithms must be designed so that they are flexible. A complete selection of tools is necessary to allow arbitrary specification of views, extraction of qualitative information, and access to detailed quantitative and problem information. Finally, full use of advanced display hardware is necessary if interactivity is to be maximized and effective postprocessing of today's numerical simulations is to be achieved.
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.
Three-dimensional tissue culture based on magnetic cell levitation.
Souza, Glauco R; Molina, Jennifer R; Raphael, Robert M; Ozawa, Michael G; Stark, Daniel J; Levin, Carly S; Bronk, Lawrence F; Ananta, Jeyarama S; Mandelin, Jami; Georgescu, Maria-Magdalena; Bankson, James A; Gelovani, Juri G; Killian, T C; Arap, Wadih; Pasqualini, Renata
2010-04-01
Cell culture is an essential tool in drug discovery, tissue engineering and stem cell research. Conventional tissue culture produces two-dimensional cell growth with gene expression, signalling and morphology that can be different from those found in vivo, and this compromises its clinical relevance. Here, we report a three-dimensional tissue culture based on magnetic levitation of cells in the presence of a hydrogel consisting of gold, magnetic iron oxide nanoparticles and filamentous bacteriophage. By spatially controlling the magnetic field, the geometry of the cell mass can be manipulated, and multicellular clustering of different cell types in co-culture can be achieved. Magnetically levitated human glioblastoma cells showed similar protein expression profiles to those observed in human tumour xenografts. Taken together, these results indicate that levitated three-dimensional culture with magnetized phage-based hydrogels more closely recapitulates in vivo protein expression and may be more feasible for long-term multicellular studies.
Moyamoya disease: diagnosis with three-dimensional CT angiography
Energy Technology Data Exchange (ETDEWEB)
Tsuchiya, K. (Dept. of Radiology, National Defense Medical Coll., Saitama (Japan) Dept. of Radiology, Kyorin Univ. School of Medicine, Tokyo (Japan)); Makita, K. (Dept. of Radiology, National Defense Medical Coll., Saitama (Japan) Dept. of Radiology, Social Health Insurance Medical Center, Tokyo (Japan)); Furui, S. (Dept. of Radiology, National Defense Medical Coll., Saitama (Japan) Dept. of Diagnostic Radiology, Toranomon Kyosai Hospital, Tokyo (Japan))
1994-08-01
Our purpose was to assess the value of three-dimensional (3D) CT angiography in the diagnosis of moyamoya disease. We studied seven patients with moyamoya disease proved by conventional angiography. Three-dimensional (3D) CT angiography was performed using rapid sequence or helical (spiral) scanning in conjunction with a bolus injection of intravenous contrast medium. All seven patients could be diagnosed as having moyamoya disease on the basis of the following 3D CT angiographic findings: poor visualisation of the main trunks and/or major branches of anterior and middle cerebral arteries (7 patients); dilated leptomeningeal anastomotic channels from the posterior cerebral arteries (4); and demonstration of ''moyamoya vessels'' in the basal ganglia (2). Although conventional angiography remains the principal imaging technique for demonstrating anatomical changes in detail, less invasive 3D CT angiography provides a solid means of diagnosing moyamoya disease when it is suspected on CT, MRI, or clinical grounds. (orig.)
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.
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.
Three-dimensional modelling in magnetotelluric and magnetic variational sounding
Reddy, I. K.; Phillips, R. J.; Rankin, D.
1977-01-01
The Galerkin finite-element method is used to obtain approximate solutions for the three-dimensional induction problem. A rectangular conductive prism is considered as an example, and solutions are obtained for linear and circularly polarized incident plane-wave fields. Magnetotelluric tensor impedances and magnetic transfer functions are computed. Polar diagrams of the tensor impedances and magnetic transfer functions along with their amplitude contour maps are presented. The dimensionality parameter, skew, is contoured at the surface of the earth. It is shown that the relative amplitudes and shapes of the additional and principal impedance polar diagrams can be used to determine the dimensionality of geoelectrical structures. Stations with skew values greater than 0.2 are significantly influenced by the three-dimensionality of the geoelectric structure. The amplitudes of the magnetic transfer function and the orientations of its polar diagrams exhibit large anomalies in the vicinity of the intersection of the lateral contacts.
Finite element solution theory for three-dimensional boundary flows
Baker, A. J.
1974-01-01
A finite element algorithm is derived for the numerical solution of a three-dimensional flow field described by a system of initial-valued, elliptic boundary value partial differential equations. The familiar three-dimensional boundary layer equations belong to this description when diffusional processes in only one coordinate direction are important. The finite element algorithm transforms the original description into large order systems of ordinary differential equations written for the dependent variables discretized at node points of an arbitrarily irregular computational lattice. The generalized elliptic boundary conditions is piecewise valid for each dependent variable on boundaries that need not explicitly coincide with coordinate surfaces. Solutions for sample problems in laminar and turbulent boundary flows illustrate favorable solution accuracy, convergence, and versatility.
Three-dimensional simulations of Nova capsule implosion experiments
Energy Technology Data Exchange (ETDEWEB)
Marinak, M.M.; Tipton, R.E.; Landen, O.L. [and others
1995-11-01
Capsule implosion experiments carried out on the Nova laser are simulated with the three-dimensional HYDRA radiation hydrodynamics code. Simulations of ordered near single mode perturbations indicate that structures which evolve into round spikes can penetrate farthest into the hot spot. Bubble-shaped perturbations can burn through the capsule shell fastest, however, causing even more damage. Simulations of a capsule with multimode perturbations shows spike amplitudes evolving in good agreement with a saturation model during the deceleration phase. The presence of sizable low mode asymmetry, caused either by drive asymmetry or perturbations in the capsule shell, can dramatically affect the manner in which spikes approach the center of the hot spot. Three-dimensional coupling between the low mode shell perturbations intrinsic to Nova capsules and the drive asymmetry brings the simulated yields into closer agreement with the experimental values.
Viscous three-dimensional analyses for nozzles for hypersonic propulsion
Harloff, G. J.; Reddy, D. R.; Lai, H. T.
1990-01-01
A Navier-Stokes computer code was validated using a number of two- and three-dimensional configurations for both laminar and turbulent flows. The validation data covers a range of freestream Mach numbers from 3 to 14, including wall pressures, velocity pressure, and skin friction. Nozzle flow fields computed for a generic scramjet nozzle from Mach 3 to 20, wall pressures, wall skin friction values, heat transfer values, and overall performance are presented. In addition, three-dimensional solutions obtained for two asymmetric, single expansion ramp nozzles at a pressure ratio of 10 consists of the internal expansion region in the converging/diverging sections and the external superonic exhaust in a quiescent ambient environment. The fundamental characteristics that were captured successfully include expansion fans; Mach wave reflections; mixing layers; and nonsymmetrical, multiple inviscid cell, supersonic exhausts. Comparison with experimental data for wall pressure distributions at the center planes shows good agreement.
Structure and topology of three-dimensional hydrocarbon polymers.
Kondrin, Mikhail V; Lebed, Yulia B; Brazhkin, Vadim V
2016-08-01
A new family of three-dimensional hydrocarbon polymers which are more energetically favorable than benzene is proposed. Although structurally these polymers are closely related to well known diamond and lonsdaleite carbon structures, using topological arguments we demonstrate that they have no known structural analogs. Topological considerations also give some indication of possible methods of synthesis. Taking into account their exceptional optical, structural and mechanical properties these polymers might have interesting applications.
Unsteady three-dimensional simulation of VTOL upwash fountain turbulence
Childs, Robert E.; Nixon, David
1987-01-01
Numerical simulations of a planar turbulent wall jet and a planar VTOL upwash fountain were performed. These are three dimensional simulations which resolve large scale unsteady motions in the flows. The wall jet simulation shows good agreement with experimental data and is presented to verify the simulation methodology. Simulation of the upwash fountain predicts elevated shear stress and a half velocity width spreading rate of 33% which agrees well with experiment. Turbulence mechanisms which contribute to the enhanced spreading rate are examined.
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.
Ion beam polishing for three-dimensional electron backscattered diffraction
DEFF Research Database (Denmark)
Saowadee, Nath; Agersted, Karsten; Ubhi, H.S.
2013-01-01
Serial sectioning by focused ion beam milling for three-dimensional electron backscatter diffraction (3D-EBSD) can create surface damage and amorphization in certain materials and consequently reduce the EBSD signal quality. Poor EBSD signal causes longer data acquisition time due to signal avera.......3% of normal 3D-EBSD mapping compared to a significant increase of indexing percentage and pattern quality. The polishing performance in this investigation is discussed, and two potential methods for further improvement are presented....
MRFD Method for Scattering From Three Dimensional Dielectric Bodies
Directory of Open Access Journals (Sweden)
A. F. Yagli
2011-09-01
Full Text Available A three-dimensional multiresolution frequency domain (MRFD method is established to compute bistatic radar cross sections of arbitrarily shaped dielectric objects. The proposed formulation is successfully verified by computing the bistatic radar cross sections of a dielectric sphere and a dielectric cube. Comparing the results to those obtained from the finite difference frequency domain (FDFD method simulations and analytic calculations, we demonstrated the computational time and memory advantages of MRFD method.
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.
Generators of quasiperiodic oscillations with three-dimensional phase space
DEFF Research Database (Denmark)
Kuznetsov, A.P.; Kuznetsov, S.P.; Mosekilde, Erik
2013-01-01
Considering a family of three-dimensional oscillators originating in the field of radio-engineering, the paper describes three different mechanisms of torus formation. Particular emphasis is paid to a process in which a saddle-node bifurcation eliminates a stable cycle and leaves the system to fi...... a stationary state between a saddle cycle and a pair of equilibrium points of unstable focus/stable node and unstable node/stable focus type....
Convection Effects in Three-dimensional Dendritic Growth
Lu, Yili; Beckermann, C.; Karma, A.
2003-01-01
A phase-field model is developed to simulate free dendritic growth coupled with fluid flow for a pure material in three dimensions. The preliminary results presented here illustrate the strong influence of convection on the three-dimensional (3D) dendrite growth morphology. The detailed knowledge of the flow and temperature fields in the melt around the dendrite from the simulations allows for a detailed understanding of the convection effects on dendritic growth.
AUTOMATED PLASTIC DESING OF THREE DIMENSIONAL STEEL STRUCTURES
Directory of Open Access Journals (Sweden)
Hasan GÖNEN
1998-02-01
Full Text Available In this study a computer program is presented for an efficient automated design procedure for the analysis and design of two and three dimensional steel frames. Here applied loads may be developed as a lineer combination of three vertical load conditions, two static lateral load conditions, and two independent response spectra. The program is able to estimate P-delta effects, enforce strong column-weak girder strategy, and satisfy the story drift criteria.
Three-dimensional echocardiographic assessment of atrial septal defects
German, Charles; Nanda, Navin C.
2015-01-01
Echocardiography provides a useful tool in the diagnosis of many congenital heart diseases, including atrial septal defects, and aids in further delineating treatment options. Although two-dimensional echocardiography has been the standard of care in this regard, technological advancements have made three-dimensional echocardiography possible, and the images obtained in this new imaging modality are able to accurately portray the morphology, location, dimensions, and dynamic changes of defects and many other heart structures during the cardiac cycle. PMID:25566714
Random matrix theory and three-dimensional QCD
Energy Technology Data Exchange (ETDEWEB)
Verbaarschot, J.J.M.; Zahed, I. (Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794 (United States))
1994-10-24
We suggest that the spectral properties near zero virtuality of three-dimensional QCD follow from a Hermitian random matrix model. The exact spectral density is derived for this family of random matrix models for both even and odd number of fermions. New sum rules for the inverse powers of the eigenvalues of the Dirac operator are obtained. The issue of anomalies in random matrix theories is discussed.
Temporal Enhancement of Three Dimensional Echocardiography by Frame Reordering
Perrin, Douglas P.; Vasilyev, Nikolay V.; Marx, Gerald R; Pedro J. del Nido
2012-01-01
In this work we describe a method to increase the frame rate for three dimensional ultrasound sequences of periodically moving cardiac structures by reordering the acquired volume series. Frame rate is especially important in studying intracardiac structures such as valve leaflet motion where valve closure times are on the order of milliseconds. Current commercially available systems for volumetric ultrasound imaging are limited to approximately 10–20 volumes per second. While this frame rate...
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.
Three-dimensional TDHF calculation for reactions of unstable nuclei
Energy Technology Data Exchange (ETDEWEB)
Kim, Ka-Hae; Otsuka, Takaharu [Tokyo Univ. (Japan). Dept. of Physics; Bonche, P.
1998-07-01
The fusion is studied for reactions between a stable and an unstable nuclei with neutron skin. The reactions {sup 16,28}O+{sup 40}Ca and {sup 16}O+{sup 16,28}O are taken as examples, and the three-dimensional time-dependent Hartree-Fock method with the full Skyrme interaction is used. It is confirmed that the fusion cross section in low-energy region is sensitive to the interaction used in the calculation. (author)
Imaging Cells in Three-Dimensional Collagen Matrix
Artym, Vira V.; Matsumoto, Kazue
2010-01-01
The use of in vitro three-dimensional (3D) collagen matrices to mimic an in vivo cellular environment has become increasingly popular and is broadening our understanding of cellular processes and cell - ECM interactions. To study cells in in vitro 3D collagen matrices, both cellular proteins and the collagen matrix must be visualized. In this unit, the authors describe the protocol and provide troubleshooting for immuno-labeling of cells in 3D collagen gels to localize and visualize cellular ...
Three-dimensional echocardiographic assessment of atrial septal defects
Directory of Open Access Journals (Sweden)
Charles German
2015-01-01
Full Text Available Echocardiography provides a useful tool in the diagnosis of many congenital heart diseases, including atrial septal defects, and aids in further delineating treatment options. Although two-dimensional echocardiography has been the standard of care in this regard, technological advancements have made three-dimensional echocardiography possible, and the images obtained in this new imaging modality are able to accurately portray the morphology, location, dimensions, and dynamic changes of defects and many other heart structures during the cardiac cycle.
MATERIALS COMPATIBILITY STUDY FOR THREE-DIMENSIONAL PRINTER MATERIALS
2017-09-01
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...three-dimensional (3D) printing has emerged as a disruptive technology in areas of both durable and consumable plastics . Varieties of plastics to serve...interest because of the high volume of plastics used in research laboratories. A significant portion of laboratory consumables is made up of plastic
Three-dimensional residual strain in midanterior canine left ventricle
Costa, Kevin D; MAY-NEWMAN, KAREN; FARR, DYAN; O’Dell, Walter G.; McCulloch, Andrew D.; Omens, Jeffrey H.
1997-01-01
All previous studies of residual strain in the ventricular wall have been based on one- or two-dimensional measurements. Transmural distributions of three-dimensional (3-D) residual strains were measured by biplane radiography of columns of lead beads implanted in the midanterior free wall of the canine left ventricle (LV). 3-D bead coordinates were reconstructed with the isolated arrested LV in the zero-pressure state and again after local residual stress had been relieved by excising a tran...
THREE-DIMENSIONAL LOADING AND GROWTH OF THE ZYGOMATIC ARCH
RAFFERTY, KATHERINE L.; HERRING, SUSAN W.; ARTESE, FLAVIA
2000-01-01
Despite a number of previous biomechanical studies on the zygomatic arch, unanswered questions remain about its three-dimensional loading and growth. Using young miniature swine, we have for the first time recorded strains from both the medial and lateral aspects of the squamosal bone during mastication and masseter muscle stimulation. Strains from the zygomatic bone flange and zygomatic arch growth data were also obtained from the same animals. A second study on a younger group of animals ex...
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.
Life is three-dimensional, and it begins with molecules
Bourne, Philip E.
2017-01-01
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 socie...
System and Device with Three-Dimensional Image Display
DEFF Research Database (Denmark)
2012-01-01
The present invention relates to a binocular device (44) and a system (40) including a binocular device (44) configured for displaying one or more labels for an input device (2), such as a keyboard or a control panel, comprising a plurality of parts (4, 6) configured for activation and registration...... by depression. The binocular device (44) is configured for displaying a label of an activation part (4) as a three-dimensional label at the activation part (4)....
Three-dimensional magnetic recording using ferromagnetic resonance
Suto, Hirofumi; Kudo, Kiwamu; Nagasawa, Tazumi; Kanao, Taro; Mizushima, Koichi; Sato, Rie
2016-07-01
To meet the ever-increasing demand for data storage, future magnetic recording devices will need to be made three-dimensional by implementing multilayer recording. In this article, we present methods of detecting and manipulating the magnetization direction of a specific layer selectively in a vertically stacked multilayer magnetic system, which enable layer-selective read and write operations in three-dimensional magnetic recording devices. The principle behind the methods is ferromagnetic resonance excitation in a microwave magnetic field. By designing each magnetic recording layer to have a different ferromagnetic resonance frequency, magnetization excitation can be induced individually in each layer by tuning the frequency of an applied microwave magnetic field, and this selective magnetization excitation can be utilized for the layer-selective operations. Regarding media for three-dimensional recording, when layers of a perpendicular magnetic material are vertically stacked, dipolar interaction between multiple recording layers arises and is expected to cause problems, such as degradation of thermal stability and switching field distribution. To solve these problems, we propose the use of an antiferromagnetically coupled structure consisting of hard and soft magnetic layers. Because the stray fields from these two layers cancel each other, antiferromagnetically coupled media can reduce the dipolar interaction.
Three-dimensional features on oscillating microbubbles streaming flows
Rossi, Massimiliano; Marin, Alvaro G.; Wang, Cheng; Hilgenfeldt, Sascha; Kähler, Christian J.
2013-11-01
Ultrasound-driven oscillating micro-bubbles have been used as active actuators in microfluidic devices to perform manifold tasks such as mixing, sorting and manipulation of microparticles. A common configuration consists in side-bubbles, created by trapping air pockets in blind channels perpendicular to the main channel direction. This configuration results in bubbles with a semi-cylindrical shape that creates a streaming flow generally considered quasi two-dimensional. However, recent experiments performed with three-dimensional velocimetry methods have shown how microparticles can present significant three-dimensional trajectories, especially in regions close to the bubble interface. Several reasons will be discussed such as boundary effects of the bottom/top wall, deformation of the bubble interface leading to more complex vibrational modes, or bubble-particle interactions. In the present investigation, precise measurements of particle trajectories close to the bubble interface will be performed by means of 3D Astigmatic Particle Tracking Velocimetry. The results will allow us to characterize quantitatively the three-dimensional features of the streaming flow and to estimate its implications in practical applications as particle trapping, sorting or mixing.
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.
Three-dimensional fluorescence characteristics of white chrysanthemum flowers
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.
Nonlinear three-dimensional trajectory following: simulation and application
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.
Simulation research on three-dimensional immune GA used to solve TP
Jin, Liang-Ping; Zhong, Jun-Hua
2013-03-01
Timetabling Problem (TP) in colleges and universities has become more important and complicated with the further reform in teaching and growing expansion of recruitment scale. In this paper, an optimized mathematical model of TP was established .The framework structure to solve TP was found. According to characteristics of TP, GA was introduced, a variety of improved schemes were designed, include: three-dimensional coding scheme, fitness function design scheme, immunization strategy. Simulation results show that the proposed GA can satisfy multiple constraint conditions and resolve TP more effectively.
Three-dimensional appearance of the lips muscles with three-dimensional isotropic MRI: in vivo study
Energy Technology Data Exchange (ETDEWEB)
Olszewski, Raphael; Reychler, H. [Universite Catholique de Louvain, Department of Oral and Maxillofacial Surgery, Cliniques Universitaires Saint Luc, Brussels (Belgium); Liu, Y.; Xu, T.M. [Peking University School and Hospital of Stomatology, Department of Orthodontics, Beijing (China); Duprez, T. [Universite Catholique de Louvain, Department of Radiology, Cliniques Universitaires Saint Luc, Brussels (Belgium)
2009-06-15
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. (orig.)
a Three-Dimensional Acoustical Imaging System for Zooplankton Observations
McGehee, Duncan Ewell
This dissertation describes the design, testing, and use of a three-dimensional acoustical imaging system, called Fish TV, or FTV, for tracking zooplankton swimming in situ. There is an increasing recognition that three -dimensional tracks of individual plankters are needed for some studies in behavioral ecology including, for example, the role of individual behavior in patch formation and maintenance. Fish TV was developed in part to provide a means of examining zooplankton swimming behavior in a non-invasive way. The system works by forming a set of 64 acoustic beams in an 8 by 8 pattern, each beam 2 ^circ by 2^circ , for a total coverage of 16^circ by 16^circ. The 8 by 8 beams form two dimensions of the image; range provides the third dimension. The system described in the thesis produces three-dimensional images at the rate of approximately one per second. A set of laboratory and field experiments is described that demonstrates the capabilities of the system. The final field experiment was the in situ observation of zooplankton swimming behavior at a site in the San Diego Trough, 15 nautical miles southwest of San Diego. 314 plankters were tracked for one minute. It was observed that there was no connection between the acoustic size of the animals and their repertoire of swimming behaviors. Other contributions of the dissertation include the development of two novel methods for generating acoustic beams with low side lobes. The first is the method of dense random arrays. The second is the optimum mean square quantized aperture method. Both methods were developed originally as ways to "build a better beam pattern" for Fish TV, but also have general significance with respect to aperture theory.
Magnetic ratchet for three-dimensional spintronic memory and logic.
Lavrijsen, Reinoud; Lee, Ji-Hyun; Fernández-Pacheco, Amalio; Petit, Dorothée C M C; Mansell, Rhodri; Cowburn, Russell P
2013-01-31
One of the key challenges for future electronic memory and logic devices is finding viable ways of moving from today's two-dimensional structures, which hold data in an x-y mesh of cells, to three-dimensional structures in which data are stored in an x-y-z lattice of cells. This could allow a many-fold increase in performance. A suggested solution is the shift register--a digital building block that passes data from cell to cell along a chain. In conventional digital microelectronics, two-dimensional shift registers are routinely constructed from a number of connected transistors. However, for three-dimensional devices the added process complexity and space needed for such transistors would largely cancel out the benefits of moving into the third dimension. 'Physical' shift registers, in which an intrinsic physical phenomenon is used to move data near-atomic distances, without requiring conventional transistors, are therefore much preferred. Here we demonstrate a way of implementing a spintronic unidirectional vertical shift register between perpendicularly magnetized ferromagnets of subnanometre thickness, similar to the layers used in non-volatile magnetic random-access memory. By carefully controlling the thickness of each magnetic layer and the exchange coupling between the layers, we form a ratchet that allows information in the form of a sharp magnetic kink soliton to be unidirectionally pumped (or 'shifted') from one magnetic layer to another. This simple and efficient shift-register concept suggests a route to the creation of three-dimensional microchips for memory and logic applications.
Strongly interacting atom lasers in three-dimensional optical lattices.
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.
Integrating three-dimensional printing and nanotechnology for musculoskeletal regeneration
Nowicki, Margaret; Castro, Nathan J.; Rao, Raj; Plesniak, Michael; Zhang, Lijie Grace
2017-09-01
The field of tissue engineering is advancing steadily, partly due to advancements in rapid prototyping technology. Even with increasing focus, successful complex tissue regeneration of vascularized bone, cartilage and the osteochondral interface remains largely illusive. This review examines current three-dimensional printing techniques and their application towards bone, cartilage and osteochondral regeneration. The importance of, and benefit to, nanomaterial integration is also highlighted with recent published examples. Early-stage successes and challenges of recent studies are discussed, with an outlook to future research in the related areas.
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.
Three-Dimensional Cell Cultures in Drug Discovery and Development
Fang, Ye; Eglen, Richard M.
2017-01-01
The past decades have witnessed significant efforts toward the development of three-dimensional (3D) cell cultures as systems that better mimic in vivo physiology. Today, 3D cell cultures are emerging, not only as a new tool in early drug discovery but also as potential therapeutics to treat disease. In this review, we assess leading 3D cell culture technologies and their impact on drug discovery, including spheroids, organoids, scaffolds, hydrogels, organs-on-chips, and 3D bioprinting. We also discuss the implementation of these technologies in compound identification, screening, and development, ranging from disease modeling to assessment of efficacy and safety profiles. PMID:28520521
Three-dimensional aerodynamic shape optimization of supersonic delta wings
Burgreen, Greg W.; Baysal, Oktay
1994-01-01
A recently developed three-dimensional aerodynamic shape optimization procedure AeSOP(sub 3D) is described. This procedure incorporates some of the most promising concepts from the area of computational aerodynamic analysis and design, specifically, discrete sensitivity analysis, a fully implicit 3D Computational Fluid Dynamics (CFD) methodology, and 3D Bezier-Bernstein surface parameterizations. The new procedure is demonstrated in the preliminary design of supersonic delta wings. Starting from a symmetric clipped delta wing geometry, a Mach 1.62 asymmetric delta wing and two Mach 1. 5 cranked delta wings were designed subject to various aerodynamic and geometric constraints.
Elliptic surface grid generation in three-dimensional space
Kania, Lee
1992-01-01
A methodology for surface grid generation in three dimensional space is described. The method solves a Poisson equation for each coordinate on arbitrary surfaces using successive line over-relaxation. The complete surface curvature terms were discretized and retained within the nonhomogeneous term in order to preserve surface definition; there is no need for conventional surface splines. Control functions were formulated to permit control of grid orthogonality and spacing. A method for interpolation of control functions into the domain was devised which permits their specification not only at the surface boundaries but within the interior as well. An interactive surface generation code which makes use of this methodology is currently under development.
Three-Dimensional Intercalated Porous Graphene on Si(111)
Pham, Trung T.; Sporken, Robert
2018-02-01
Three-dimensional intercalated porous graphene has been formed on Si(111) by electron beam evaporation under appropriate conditions and its structural and electronic properties investigated in detail by reflection high-energy electron diffraction, x-ray photoemission spectroscopy, Raman spectroscopy, high-resolution scanning electron microscopy, atomic force microscopy, and scanning tunneling microscopy. The results show that the crystalline quality of the porous graphene depended not only on the substrate temperature but also on the SiC layer thickness during carbon atom deposition.
Three-dimensional characterization of stress corrosion cracks
DEFF Research Database (Denmark)
Lozano-Perez, S.; Rodrigo, P.; Gontard, Lionel Cervera
2011-01-01
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...... 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...
Three-dimensional phase-field simulations of directional solidification
Plapp, Mathis
2007-05-01
The phase-field method has become the method of choice for simulating microstructural pattern formation during solidification. One of its main advantages is that time-dependent three-dimensional simulations become feasible, which makes it possible to address long-standing questions of pattern stability and pattern selection. Here, a brief introduction to the phase-field model and its implementation is given, and its capabilities are illustrated by examples taken from the directional solidification of binary alloys. In particular, the morphological stability of hexagonal cellular arrays and of eutectic lamellar patterns is investigated.
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.
CATIA Core Tools Computer Aided Three-Dimensional Interactive Application
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.
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...
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.
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.
A Three-Dimensional GUI for Windows Explorer
Carter, David; Capretz, Luiz Fernando
2015-01-01
Three-dimension will be a characteristic of future user interfaces, although we are just starting to gain an understanding of how users can navigate and share information within a virtual 3D environment. Three-dimensional graphical user interfaces (3D-GUI) raise many issues of design, metaphor and usability. This research is devoted to designing a 3D-GUI as a front-end tool for a file management system, in this case, for Microsoft Windows\\c{opyright} Explorer; as well as evaluating the effici...
Light-folded projection three-dimensional display.
Jang, Jaehyuk; Hong, Jongwoo; Kim, Hwi; Hahn, Joonku
2013-04-01
A light-folded projection three-dimensional (3D) display system with a single projection lens and a rectangular light tunnel which is composed of four folding mirrors on its inside walls is proposed. It is theoretically shown through the Wigner distribution function analysis that the proposed system can generate the same light field effectively as that of the conventional projection-type multiview 3D display system with plural projection lenses. Multiview 3D imaging of the proposed system configuration is experimentally demonstrated.
Three-dimensional tissue culture models in cancer biology.
Kim, Jong Bin
2005-10-01
Three-dimensional (3D) tissue culture models have an invaluable role in tumour biology today providing some very important insights into cancer biology. As well as increasing our understanding of homeostasis, cellular differentiation and tissue organization they provide a well defined environment for cancer research in contrast to the complex host environment of an in vivo model. Due to their enormous potential 3D tumour cultures are currently being exploited by many branches of biomedical science with therapeutically orientated studies becoming the major focus of research. Recent advances in 3D culture and tissue engineering techniques have enabled the development of more complex heterologous 3D tumour models.
Study of Three-Dimensional Image Brightness Loss in Stereoscopy
Hsing-Cheng Yu; Xie-Hong Tsai; An-Chun Luo; Ming Wu; Sei-Wang Chen
2015-01-01
When viewing three-dimensional (3D) images, whether in cinemas or on stereoscopic televisions, viewers experience the same problem of image brightness loss. This study aims to investigate image brightness loss in 3D displays, with the primary aim being to quantify the image brightness degradation in the 3D mode. A further aim is to determine the image brightness relationship to the corresponding two-dimensional (2D) images in order to adjust the 3D-image brightness values. In addition, the ph...
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...... based on the accomplishmentsrecently reported. Th e chapter will include: (1) a brief introduction to grapheneand its nanocomposites, (2) the major methods to assemble 3D porous graphenenetworks, (3) structural characteristics of 3D porous graphene, (4) some typicalexamples of their applications...
Measurement of three-dimensional temperature fields with interferometric tomography.
Wu, D; He, A
1999-06-01
Optical computerized tomography (OCT) technology is used to reconstruct the asymmetric three-dimensional temperature field generated by radiators and electronic chips. First, the OCT method is described. Second, the reconstructed results are tested by a double-cylinder radiator model. Finally, OCT is applied to reconstruction of the temperature field above the surface of a CPU. The air-temperature field above a CPU circuit can be imaged with an OCT system that reflects whether the heat production from different parts of the CPU is even; therefore possibly the technique can be used to determine whether the integrated-circuit design in the CPU is smart.
Exceptional points in three-dimensional plasmonic nanostructures
Kodigala, Ashok; Lepetit, Thomas; Kanté, Boubacar
2016-11-01
Exceptional points (EPs) are degeneracies in open wave systems where at least two energy levels and their corresponding eigenstates coalesce. We report evidence of the existence of EPs in three-dimensional (3D) plasmonic nanostructures. The systems are composed of coupled plasmonic nanoresonators and can be judiciously and systematically driven to EPs by controlling symmetry-compatible modes via their near-field and far-field interactions. The proposed platform opens the way to the investigation of EPs for enhanced light-matter interactions and applications in communication, sensing, and imaging.
Canonical and symplectic analysis for three dimensional gravity without dynamics
Escalante, Alberto; Osmart Ochoa-Gutiérrez, H.
2017-03-01
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.
Nitsche's method for two and three dimensional NURBS patch coupling
Nguyen, Vinh Phu; Kerfriden, Pierre; Brino, Marco; Bordas, Stéphane P. A.; Bonisoli, Elvio
2014-06-01
We present a Nitche's method to couple non-conforming two and three-dimensional non uniform rational b-splines (NURBS) patches in the context of isogeometric analysis. We present results for linear elastostatics in two and and three-dimensions. The method can deal with surface-surface or volume-volume coupling, and we show how it can be used to handle heterogeneities such as inclusions. We also present preliminary results on modal analysis. This simple coupling method has the potential to increase the applicability of NURBS-based isogeometric analysis for practical applications.
Three-dimensional imaging of direct-written photonic structures
Marshall, Graham D; Thayil, Anisha; Withford, Michael J; Booth, Martin
2010-01-01
Third harmonic generation microscopy has been used to analyze the morphology of photonic structures created using the femtosecond laser direct-write technique. Three dimensional waveguide arrays and waveguide-Bragg gratings written in fused-silica and doped phosphate glass were investigated. A sensorless adaptive optical system was used to correct the optical aberrations occurring in the sample and microscope system, which had a lateral resolution of less than 500 nm. This non-destructive testing method creates volume reconstructions of photonic devices and reveals details invisible to other linear microscopy and index profilometry techniques.
Three-Dimensional Structure of CeO2 Nanocrystals
DEFF Research Database (Denmark)
Tan, Joyce Pei Ying; Tan, Hui Ru; Boothroyd, Chris
2011-01-01
Visualization of three-dimensional (3D) structures of materials at the nanometer scale can shed important information on the performance of their applications and provide insight into the growth mechanism of shape-controlled nanomaterials. In this paper, the 3D structures and growth pathway of CeO2...... in samples synthesized under different conditions. The homogeneous growth environment in solution with polyvinylpyrrolidone (PVP) molecules led to the formation of regular octahedral CeO2 nanocrystals with small {001} facet truncations. When the PVP surfactant was removed, the aggregation of regular...
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.
Three dimensional reflectance properties of superconductor-dielectric photonic crystal
Energy Technology Data Exchange (ETDEWEB)
Pandey, G. N., E-mail: gnpandey@amity.edu; Sancheti, Bhagyashree [Department of Physics, Amity Institute of Applied Sciences, Amity University, Noida (U.P.) (India); Pandey, J. P.; Pandey, U. K. [Department of Physics, M.L.K. P.G.College, Balrampur (U.P.) (India); Ojha, S. P. [Department of Physics, IIT, BHU, Varanasi-(UP) (India)
2016-05-06
In this present communication, we have studied the optical properties of Photonics Crystals with super conducting constituent using the TMM method for a stratified medium. We also studied the three dimensional reflectance property of superconductor-dielectric photonic crystal at different temperature and thickness. From above study we show that the superconductor-dielectric photonic crystal may be used as broad band reflector and omnidirectional reflector at low temperature below to the critical temperature. Such property may be applied to make of the reflector which can be used in low temperature region.
Design of three-dimensional scramjet inlets for hypersonic propulsion
Simmons, J. M.; Weidner, E. H.
1986-01-01
The paper outlines an approach to the design of three-dimensional inlets for scramjet engines. The basis of the techniques used is the method of streamline tracing through an inviscid axisymmetric flow field. A technique is described for making a smooth change of cross-section shape from rectangular to circular. A feature is the considerable use of computer-graphics to provide a 'user-oriented' procedure which can produce promising design configurations for subsequent analysis with CFD codes. An example is given to demonstrate the capabilities of the design techniques.
Three-dimensional illumination procedure for photodynamic therapy of dermatology
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.
Optical Forging of Graphene into Three-Dimensional Shapes.
Johansson, Andreas; Myllyperkiö, Pasi; Koskinen, Pekka; Aumanen, Jukka; Koivistoinen, Juha; Tsai, Hung-Chieh; Chen, Chia-Hao; Chang, Lo-Yueh; Hiltunen, Vesa-Matti; Manninen, Jyrki J; Woon, Wei Yen; Pettersson, Mika
2017-10-11
Atomically thin materials, such as graphene, are the ultimate building blocks for nanoscale devices. But although their synthesis and handling today are routine, all efforts thus far have been restricted to flat natural geometries, since the means to control their three-dimensional (3D) morphology has remained elusive. Here we show that, just as a blacksmith uses a hammer to forge a metal sheet into 3D shapes, a pulsed laser beam can forge a graphene sheet into controlled 3D shapes in the nanoscale. The forging mechanism is based on laser-induced local expansion of graphene, as confirmed by computer simulations using thin sheet elasticity theory.
Satheesh Chandran, P. R.; Soumya Mol, U. S.; Drisya, R.; Sudarsanakumar, M. R.; Prathapachandra Kurup, M. R.
2017-06-01
A new Ce(III) complex of 5-aminoisophthalic acid (H2aip), [Ce(CH3COO)(aip)(H2O)2]·H2O, has been prepared by single gel diffusion technique at room temperature using sodium metasilicate. The gel-grown crystals were characterised by CHN analysis, thermogravimetry, FT-IR and UV- Visible spectral studies. The single crystal X- ray diffraction studies reveal that the title compound crystallizes in monoclinic space group P21/c. CeO9 polyhedra have distorted tricapped trigonal prism geometry and form edge sharing dimers. The adjacent dimers are connected by aip2- in different directions and generate a three dimensional network structure with hydrophilic channels. The luminescent behaviour of the complex and the ligand were also investigated and the complex shows blue shifted emission.
Three-dimensional solidification and melting using magnetic field control
Dulikravich, George S.; Ahuja, Vineet
1993-01-01
A new two-fluid mathematical model for fully three dimensional steady solidification under the influence of an arbitrary acceleration vector and with or without an arbitrary externally applied steady magnetic field have been formulated and integrated numerically. The model includes Joule heating and allows for separate temperature dependent physical properties within the melt and the solid. Latent heat of phase change during melting/solidification was incorporated using an enthalpy method. Mushy region was automatically captured by varying viscosity orders of magnitude between liquidus and solidus temperature. Computational results were obtained for silicon melt solidification in a parallelepiped container cooled from above and from a side. The results confirm that the magnetic field has a profound influence on the solidifying melt flow field thus changing convective heat transfer through the boundaries and the amount and shape of the solid accrued. This suggests that development of a quick-response algorithm for active control of three dimensional solidification is feasible since it would require low strength magnetic fields.
Three-dimensional recurring patterns in excitable media
Energy Technology Data Exchange (ETDEWEB)
Biton, Y. [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Rabinovitch, A., E-mail: avinoam@bgu.ac.il [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Braunstein, D. [Physics Department, Sami Shamoon College of Engineering, Beer-Sheva (Israel); Friedman, M. [Department of Information Systems Engineering, Ben-Gurion University, Beer-Sheva 84105 (Israel); Aviram, I. [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)
2011-06-13
A new method to create three-dimensional periodic patterns in excitable media is presented. The method is demonstrated and the patterns are obtained with the help of two types of 3D 'spiral pairs' generators, which are respectively based on a 'corner effect' and a 'unidirectional propagation' processes. The results portray time-repeating patterns resembling fruits or potteries. The method is easy to implement and can be used to form other types of 3D patterns in excitable media. The question of periodicity of the patterns thus obtained is resolved by calculating the singular lines (filaments) around which they evolve and showing their unique reattachment property. Actual realizations could be conceived e.g. in chemical reactions such as Belousov-Zhabotinsky. Possible severe cardiac arrhythmias following the appearance of such patterns in the action potential of the heart are considered. -- Highlights: → New method to create three-dimensional periodic patterns in excitable media. → Singular lines (filaments) for the corner effect are presented. → Filaments are shown to exhibit periodic behavior.
Three-dimensional bioprinting in tissue engineering and regenerative medicine.
Gao, Guifang; Cui, Xiaofeng
2016-02-01
With the advances of stem cell research, development of intelligent biomaterials and three-dimensional biofabrication strategies, highly mimicked tissue or organs can be engineered. Among all the biofabrication approaches, bioprinting based on inkjet printing technology has the promises to deliver and create biomimicked tissue with high throughput, digital control, and the capacity of single cell manipulation. Therefore, this enabling technology has great potential in regenerative medicine and translational applications. The most current advances in organ and tissue bioprinting based on the thermal inkjet printing technology are described in this review, including vasculature, muscle, cartilage, and bone. In addition, the benign side effect of bioprinting to the printed mammalian cells can be utilized for gene or drug delivery, which can be achieved conveniently during precise cell placement for tissue construction. With layer-by-layer assembly, three-dimensional tissues with complex structures can be printed using converted medical images. Therefore, bioprinting based on thermal inkjet is so far the most optimal solution to engineer vascular system to the thick and complex tissues. Collectively, bioprinting has great potential and broad applications in tissue engineering and regenerative medicine. The future advances of bioprinting include the integration of different printing mechanisms to engineer biphasic or triphasic tissues with optimized scaffolds and further understanding of stem cell biology.
Design of three-dimensional imaging system based on SFM
Yang, Hongfei; Chen, Xin; Rao, Peng
2016-03-01
For the prospects of three-dimensional reconstruction technology based on structure from motion in engineering application, a high-resolution and visible band imaging system has been designed and implemented. It consists of a 5k × 5k CMOS focal plane array detector made by the ON-SEMI company, an optical system and an electronics system designed by ourselves. The electronics system takes FPGA as the control and drive processor chip and is divided into three parts: a power management module, a detector module and an image processing module, capable of finishing image compression and transmission. A sequence of images for the target of long distance away is obtained from the imaging system and the images after cropping and segmentation, aiming at reducing calculation and excluding some points irrelevant with the target during reconstruction process, are took as input of structure from motion. Seeds from the match points expand from sparse points to dense points and the initial model of reconstruction target is achieved. The experiment results show that the imaging system meet the requirement of three-dimensional reconstruction in engineering application and a new novel imaging system design of graded resolution based on bionics is proposed.
Three dimensional dynamics of a flexible Motorised Momentum Exchange Tether
Ismail, N. A.; Cartmell, M. P.
2016-03-01
This paper presents a new flexural model for the three dimensional dynamics of the Motorised Momentum Exchange Tether (MMET) concept. This study has uncovered the relationships between planar and nonplanar motions, and the effect of the coupling between these two parameters on pragmatic circular and elliptical orbits. The tether sub-spans are modelled as stiffened strings governed by partial differential equations of motion, with specific boundary conditions. The tether sub-spans are flexible and elastic, thereby allowing three dimensional displacements. The boundary conditions lead to a specific frequency equation and the eigenvalues from this provide the natural frequencies of the orbiting flexible motorised tether when static, accelerating in monotonic spin, and at terminal angular velocity. A rotation transformation matrix has been utilised to get the position vectors of the system's components in an assumed inertial frame. Spatio-temporal coordinates are transformed to modal coordinates before applying Lagrange's equations, and pre-selected linear modes are included to generate the equations of motion. The equations of motion contain inertial nonlinearities which are essentially of cubic order, and these show the potential for intricate intermodal coupling effects. A simulation of planar and non-planar motions has been undertaken and the differences in the modal responses, for both motions, and between the rigid body and flexible models are highlighted and discussed.
Interface fracture in laminates at three-dimensional corners
Energy Technology Data Exchange (ETDEWEB)
Myhre Jensen, H.; Veluri, B. [Aarhus Univ.. Aarhus School of Engineering, Aarhus (Denmark)
2012-07-01
Interface failure close to corners has been observed in laminated layered structures. A fracture mechanics based approach focused on modelling the shape of such interface cracks and calculating the critical stress for steady-state propagation has been developed. The crack propagation is investigated by estimating the fracture mechanics parameters including the energy release rate and the three-dimensional mode-mixity along the crack front allowing determining the shape of the crack front profiles. A numerical approach is applied for coupling the far field solutions utilizing the capability of the Finite Element Method to the near field solutions at the crack front based on the J-integral. The developed two-dimensional numerical approach for the calculation of fracture mechanical properties has been validated with three-dimensional models for varying crack front shapes. In this study, a quantitative approach was formulated based on the finite element method with iterative adjustment of the crack front to estimate the critical delamination stress as a function of the fracture criterion and corner angles. The implication of the results on the delamination is discussed in terms of crack front profiles and the critical stresses. (Author)
Terahertz Imaging of Three-Dimensional Dehydrated Breast Cancer Tumors
Bowman, Tyler; Wu, Yuhao; Gauch, John; Campbell, Lucas K.; El-Shenawee, Magda
2017-06-01
This work presents the application of terahertz imaging to three-dimensional formalin-fixed, paraffin-embedded human breast cancer tumors. The results demonstrate the capability of terahertz for in-depth scanning to produce cross section images without the need to slice the tumor. Samples of tumors excised from women diagnosed with infiltrating ductal carcinoma and lobular carcinoma are investigated using a pulsed terahertz time domain imaging system. A time of flight estimation is used to obtain vertical and horizontal cross section images of tumor tissues embedded in paraffin block. Strong agreement is shown comparing the terahertz images obtained by electronically scanning the tumor in-depth in comparison with histopathology images. The detection of cancer tissue inside the block is found to be accurate to depths over 1 mm. Image processing techniques are applied to provide improved contrast and automation of the obtained terahertz images. In particular, unsharp masking and edge detection methods are found to be most effective for three-dimensional block imaging.
Three-dimensional flow and turbulence structure in electrostatic precipitator
DEFF Research Database (Denmark)
Ullum, Thorvald Uhrskov; Larsen, Poul Scheel; Özcan, Oktay
2002-01-01
Stereo PIV is employed to study the three-dimensional velocity and turbulence fields in a laboratory model of a negative corona, barbed-wire, smooth-plate, electrostatic precipitator (figure 1). The study is focused on determining the parametric effects of axial development, mean current density Jm...... 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...... of normal Reynolds stresses. The effects of U0 and Jm on S and Tu (at fixed position between 6th and 7th electrode) are reasonably correlated by the electrohydrodynamic modulus NEHD = (Jm/bi)ly/(½rU02), where bi denotes the ion mobility and ly the electrode-plate distance....
Topology of Flow Separation on Three-Dimensional Bodies
Chapman, Gary T.; Yates, Leslie A.
1991-01-01
In recent years there has been extensive research on three-dimensional flow separation. There are two different approaches: the phenomenological approach and a mathematical approach using topology. These two approaches are reviewed briefly and the shortcomings of some of the past works are discussed. A comprehensive approach applicable to incompressible and compressible steady-state flows as well as incompressible unsteady flow is then presented. The approach is similar to earlier topological approaches to separation but is more complete and in some cases adds more emphasis to certain points than in the past. To assist in the classification of various types of flow, nomenclature is introduced to describe the skin-friction portraits on the surface. This method of classification is then demonstrated on several categories of flow to illustrate particular points as well as the diversity of flow separation. The categories include attached, two-dimensional separation and three different types of simple, three-dimensional primary separation, secondary separation, and compound separation. Hypothetical experiments are utilized to illustrate the topological terminology and its role in characterizing these flows. These hypothetical experiments use colored oil injected onto the surface at singular points in the skin-friction portrait. Actual flow-visualization information, if available, is used to corroborate the hypothetical examples.
Modular transportation system with a three dimensional routeing
Directory of Open Access Journals (Sweden)
Löffler Christoph
2015-12-01
Full Text Available In intra-enterprise logistics and automation of manufacturing processes general a rising productivity by high flexibility is required. Existing transportation systems exclusively use two-dimensional track sections, because they can be served with standard drives. Because of these simple structures the transport speed is limited and thereby also the throughput. In this paper now a modular transportation system is presented which could reach higher speeds with a direct drive and the use of centrifugal force compensating curves. Simultaneously the system also can change the altitude. All this succeeds with the integration of three-dimensional track sections. Therefore a two piped guiding system with a long stator linear motor was designed. To combine the linear motor with the three dimensional track special stator elements were developed which allow a bending of the stator to follow the route course. The current work deals with the implementation of a mechanical passive switch, which is operated by the electromagnetic forces of the linear motor. So no additional mechanical actors or a separate electromagnetic system are necessary.
Horseshoe Drag in Three-dimensional Globally Isothermal Disks
Masset, F. S.; Benítez-Llambay, P.
2016-01-01
We study the horseshoe dynamics of a low-mass planet in a three-dimensional, globally isothermal, inviscid disk. We find, as reported in previous work, that the boundaries of the horseshoe region (separatrix sheets) have cylindrical symmetry about the disk’s rotation axis. We interpret this feature as arising from the fact that the whole separatrix sheets have a unique value of Bernoulli’s constant, and that this constant does not depend on altitude, but only on the cylindrical radius, in barotropic disks. We next derive an expression for the torque exerted by the horseshoe region on the planet, or horseshoe drag. Potential vorticity is not materially conserved as in two-dimensional flows, but it obeys a slightly more general conservation law (Ertel’s theorem) that allows an expression for the horseshoe drag identical to the expression in a two-dimensional disk to be obtained. Our results are illustrated and validated by three-dimensional numerical simulations. The horseshoe region is found to be slightly narrower than previously extrapolated from two-dimensional analyses with a suitable softening length of the potential. We discuss the implications of our results for the saturation of the corotation torque, and the possible connection to the flow at the Bondi scale, which the present analysis does not resolve.
Vocal Fold Pathologies and Three-Dimensional Flow Separation Phenomena
Apostoli, Adam G.; Weiland, Kelley S.; Plesniak, Michael W.
2013-11-01
Polyps and nodules are two different pathologies, which are geometric abnormalities that form on the medial surface of the vocal folds, and have been shown to significantly disrupt a person's ability to communicate. Although the mechanism by which the vocal folds self-oscillate and the three-dimensional nature of the glottal jet has been studied, the effect of irregularities caused by pathologies is not fully understood. Examining the formation and evolution of vortical structures created by a geometric protuberance is important, not only for understanding the aerodynamic forces exerted by these structures on the vocal folds, but also in the treatment of the above-mentioned pathological conditions. Using a wall-mounted prolate hemispheroid with a 2:1 aspect ratio in cross flow, the present investigation considers three-dimensional flow separation induced by a model vocal fold polyp. Building on previous work using skin friction line visualization, both the velocity flow field and wall pressure measurements around the model polyp are presented and compared. Supported by the National Science Foundation, Grant No. CBET-1236351 and GW Center for Biomimetics and Bioinspired Engineering (COBRE).
Three-dimensional volumetric quantification of fat loss following cryolipolysis.
Garibyan, Lilit; Sipprell, William H; Jalian, H Ray; Sakamoto, Fernanda H; Avram, Mathew; Anderson, R Rox
2014-02-01
Cryolipolysis is a noninvasive and well-tolerated treatment for reduction of localized subcutaneous fat. Although several studies demonstrate the safety and efficacy of this procedure, volumetric fat reduction from this treatment has not been quantified. This prospective study investigated the change in volume of fat after cryolipolysis treatment using three-dimensional (3D) photography. A prospective study of subjects treated with cryolipolysis on the flank (love handle) was performed at Massachusetts General Hospital. Volume measurements were performed with a Canfield Scientific Vectra three-dimensional camera and software to evaluate the amount of post procedure volume change. Clinical outcomes were assessed with caliper measurements, subject surveys, and blinded physician assessment of photographs. Eleven subjects were enrolled in this study. Each subject underwent a single cycle of cryolipolysis to one flank. The untreated flank served as an internal control. The follow-up time after treatment was 2 months. The mean amount of calculated absolute fat volume loss using 3D photography from baseline to 2 months follow-up visit was 56.2 ± 25.6 from the treatment site and 16.6 ± 17.6 cc from the control (P fat removal methodology that on average leads to 39.6 cc of fat loss of the treated flank at 2 months after a single treatment cycle. © 2013 Wiley Periodicals, Inc.
Three-dimensional MRI with independent slab excitation and encoding.
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.
Athermally photoreduced graphene oxides for three-dimensional holographic images
Li, Xiangping; Ren, Haoran; Chen, Xi; Liu, Juan; Li, Qin; Li, Chengmingyue; Xue, Gaolei; Jia, Jia; Cao, Liangcai; Sahu, Amit; Hu, Bin; Wang, Yongtian; Jin, Guofan; Gu, Min
2015-01-01
The emerging graphene-based material, an atomic layer of aromatic carbon atoms with exceptional electronic and optical properties, has offered unprecedented prospects for developing flat two-dimensional displaying systems. Here, we show that reduced graphene oxide enabled write-once holograms for wide-angle and full-colour three-dimensional images. This is achieved through the discovery of subwavelength-scale multilevel optical index modulation of athermally reduced graphene oxides by a single femtosecond pulsed beam. This new feature allows for static three-dimensional holographic images with a wide viewing angle up to 52 degrees. In addition, the spectrally flat optical index modulation in reduced graphene oxides enables wavelength-multiplexed holograms for full-colour images. The large and polarization-insensitive phase modulation over π in reduced graphene oxide composites enables to restore vectorial wavefronts of polarization discernible images through the vectorial diffraction of a reconstruction beam. Therefore, our technique can be leveraged to achieve compact and versatile holographic components for controlling light. PMID:25901676
CFD three dimensional wake analysis in complex terrain
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.
Three-dimensional interconnect technology for ultra-compact MMICs
Hirano, Makoto; Nishikawa, Kenjiro; Toyoda, Ichihiko; Aoyama, Shinji; Sugitani, Suehiro; Yamasaki, Kimiyoshi
1997-10-01
A novel interconnect technology was reviewed, which was developed for three-dimensional (3-D) ultra-compact MMICs. Using O 2/He RIE for the through hole and trench formation of a thick polyimide insulator layer, low-current electroplating for gold sidewall formation in the through-holes and the trenches, and ion-milling with WSiN metal stopper for gold patterning, a complete three-dimensional metal interconnection structure was built. We call this fabrication method as folded metal interconnection technology with thick insulator(FMIT). The 3-D interconnection structure involves vertical interconnection elements such as a wall-like microwire for shielding or coupling, and a pillar-like via-connection with multi-leveled planar interconnections in a 10-μm-thick polyimide matrix on an IC chip. The structure provides many passive functional elements and circuits in an extremely small area. This technology stages the next-generation of ultra-compact MMICs by offering the circuit designers great design flexibility and higher integration of circuits.
Three-dimensional visuo-motor control of saccades.
Hess, Bernhard J M
2013-01-01
Although the motion of the line of sight is a straightforward consequence of a particular rotation of the eye, it is much trickier to predict the rotation underlying a particular motion of the line of sight in accordance with Listing's law. Helmholtz's notion of the direction-circle together with the notion of primary and secondary reference directions in visual space provide an elegant solution to this reverse engineering problem, which the brain is faced with whenever generating a saccade. To test whether these notions indeed apply for saccades, we analyzed three-dimensional eye movements recorded in four rhesus monkeys. We found that on average saccade trajectories closely matched with the associated direction-circles. Torsional, vertical, and horizontal eye position of saccades scattered around the position predicted by the associated direction-circles with standard deviations of 0.5°, 0.3°, and 0.4°, respectively. Comparison of saccade trajectories with the likewise predicted fixed-axis rotations yielded mean coefficients of determinations (±SD) of 0.72 (±0.26) for torsion, 0.97 (±0.10) for vertical, and 0.96 (±0.11) for horizontal eye position. Reverse engineering of three-dimensional saccadic rotations based on visual information suggests that motor control of saccades, compatible with Listing's law, not only uses information on the fixation directions at saccade onset and offset but also relies on the computation of secondary reference positions that vary from saccade to saccade.
The Bio Bay Game: Three-Dimensional Learning of Biomagnification.
Jasti, Chandana; Lauren, Hillary; Wallon, Robert C; Hug, Barbara
2016-01-01
Pressing concerns about sustainability and the state of the environment amplify the need to teach students about the connections between ecosystem health, toxicology, and human health. Additionally, the Next Generation Science Standards call for three-dimensional science learning, which integrates disciplinary core ideas, scientific practices, and crosscutting concepts. The Bio Bay Game is a way to teach students about the biomagnification of toxicants across trophic levels while engaging them in three-dimensional learning. In the game, the class models the biomagnification of mercury in a simple aquatic food chain as they play the roles of anchovies, tuna, and humans. While playing, the class generates data, which they analyze after the game to graphically visualize the buildup of toxicants. Students also read and discuss two articles that draw connections to a real-world case. The activity ends with students applying their understanding to evaluate the game as a model of biomagnification. Throughout the activity, students practice modeling and data analysis and engage with the crosscutting concepts of patterns and cause and effect to develop an understanding of core ideas about the connections between humans and the environment.
Directory of Open Access Journals (Sweden)
Yifeng Yun
2015-03-01
Full Text Available Phase identification and structure determination are important and widely used techniques in chemistry, physics and materials science. Recently, two methods for automated three-dimensional electron diffraction (ED data collection, namely automated diffraction tomography (ADT and rotation electron diffraction (RED, have been developed. Compared with X-ray diffraction (XRD and two-dimensional zonal ED, three-dimensional ED methods have many advantages in identifying phases and determining unknown structures. Almost complete three-dimensional ED data can be collected using the ADT and RED methods. Since each ED pattern is usually measured off the zone axes by three-dimensional ED methods, dynamic effects are much reduced compared with zonal ED patterns. Data collection is easy and fast, and can start at any arbitrary orientation of the crystal, which facilitates automation. Three-dimensional ED is a powerful technique for structure identification and structure solution from individual nano- or micron-sized particles, while powder X-ray diffraction (PXRD provides information from all phases present in a sample. ED suffers from dynamic scattering, while PXRD data are kinematic. Three-dimensional ED methods and PXRD are complementary and their combinations are promising for studying multiphase samples and complicated crystal structures. Here, two three-dimensional ED methods, ADT and RED, are described. Examples are given of combinations of three-dimensional ED methods and PXRD for phase identification and structure determination over a large number of different materials, from Ni–Se–O–Cl crystals, zeolites, germanates, metal–organic frameworks and organic compounds to intermetallics with modulated structures. It is shown that three-dimensional ED is now as feasible as X-ray diffraction for phase identification and structure solution, but still needs further development in order to be as accurate as X-ray diffraction. It is expected that three-dimensional
Mano, Tomohiro; Ohtsuki, Tomi
2017-11-01
The three-dimensional Anderson model is a well-studied model of disordered electron systems that shows the delocalization-localization transition. As in our previous papers on two- and three-dimensional (2D, 3D) quantum phase transitions [https://doi.org/10.7566/JPSJ.85.123706" xlink:type="simple">J. Phys. Soc. Jpn. 85, 123706 (2016), https://doi.org/10.7566/JPSJ.86.044708" xlink:type="simple">86, 044708 (2017)], we used an image recognition algorithm based on a multilayered convolutional neural network. However, in contrast to previous papers in which 2D image recognition was used, we applied 3D image recognition to analyze entire 3D wave functions. We show that a full phase diagram of the disorder-energy plane is obtained once the 3D convolutional neural network has been trained at the band center. We further demonstrate that the full phase diagram for 3D quantum bond and site percolations can be drawn by training the 3D Anderson model at the band center.
Mapping three-dimensional temperature in microfluidic chip.
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.
Hydrogel microfabrication technology toward three dimensional tissue engineering
Directory of Open Access Journals (Sweden)
Fumiki Yanagawa
2016-03-01
Full Text Available The development of biologically relevant three-dimensional (3D tissue constructs is essential for the alternative methods of organ transplantation in regenerative medicine, as well as the development of improved drug discovery assays. Recent technological advances in hydrogel microfabrication, such as micromolding, 3D bioprinting, photolithography, and stereolithography, have led to the production of 3D tissue constructs that exhibit biological functions with precise 3D microstructures. Furthermore, microfluidics technology has enabled the development of the perfusion culture of 3D tissue constructs with vascular networks. In this review, we present these hydrogel microfabrication technologies for the in vitro reconstruction and cultivation of 3D tissues. Additionally, we discuss current challenges and future perspectives of 3D tissue engineering.
A Fermi-degenerate three-dimensional optical lattice clock
Campbell, S. L.; Hutson, R. B.; Marti, G. E.; Goban, A.; Darkwah Oppong, N.; McNally, R. L.; Sonderhouse, L.; Robinson, J. M.; Zhang, W.; Bloom, B. J.; Ye, J.
2017-10-01
Strontium optical lattice clocks have the potential to simultaneously interrogate millions of atoms with a high spectroscopic quality factor of 4 × 1017. Previously, atomic interactions have forced a compromise between clock stability, which benefits from a large number of atoms, and accuracy, which suffers from density-dependent frequency shifts. Here we demonstrate a scalable solution that takes advantage of the high, correlated density of a degenerate Fermi gas in a three-dimensional (3D) optical lattice to guard against on-site interaction shifts. We show that contact interactions are resolved so that their contribution to clock shifts is orders of magnitude lower than in previous experiments. A synchronous clock comparison between two regions of the 3D lattice yields a measurement precision of 5 × 10-19 in 1 hour of averaging time.
Rapid three dimensional two photon neural population scanning.
Schuck, Renaud; Quicke, Peter; Copeland, Caroline; Garasto, Stefania; Annecchino, Luca A; Hwang, June Kyu; Schultz, Simon R
2015-08-01
Recording the activity of neural populations at high sampling rates is a fundamental requirement for understanding computation in neural circuits. Two photon microscopy provides one promising approach towards this. However, neural circuits are three dimensional, and functional imaging in two dimensions fails to capture the 3D nature of neural dynamics. Electrically tunable lenses (ETLs) provide a simple and cheap method to extend laser scanning microscopy into the relatively unexploited third dimension. We have therefore incorporated them into our Adaptive Spiral Scanning (SSA) algorithm, which calculates kinematically efficient scanning strategies using radially modulated spiral paths. We characterised the response of the ETL, incorporated its dynamics using MATLAB models of the SSA algorithm and tested the models on populations of Izhikevich neurons of varying size and density. From this, we show that our algorithms can theoretically at least achieve sampling rates of 36.2Hz compared to 21.6Hz previously reported for 3D scanning techniques.
Agglomeration multigrid for the three-dimensional Euler equations
Venkatakrishnan, V.; Mavriplis, D. J.
1994-01-01
A multigrid procedure that makes use of coarse grids generated by the agglomeration of control volumes is advocated as a practical approach for solving the three dimensional Euler equations on unstructured grids about complex configurations. It is shown that the agglomeration procedure can be tailored to achieve certain coarse grid properties such as the sizes of the coarse grids and aspect ratios of the coarse grid cells. The agglomeration is done as a preprocessing step and runs in linear time. The implications for multigrid of using arbitrary polyhedral coarse grids are discussed. The agglomeration multigrid technique compares very favorably with existing multigrid procedures both in terms of convergence rates and elapsed times. The main advantage of the present approach is the ease with which coarse grids of any desired degree of coarseness may be generated in three dimensions, without being constrained by considerations of geometry. Inviscid flows over a variety of complex configurations are computed using the agglomeration multigrid strategy.
Three-dimensional broadband omnidirectional acoustic ground cloak
Zigoneanu, Lucian; Popa, Bogdan-Ioan; Cummer, Steven A.
2014-04-01
The control of sound propagation and reflection has always been the goal of engineers involved in the design of acoustic systems. A recent design approach based on coordinate transformations, which is applicable to many physical systems, together with the development of a new class of engineered materials called metamaterials, has opened the road to the unconstrained control of sound. However, the ideal material parameters prescribed by this methodology are complex and challenging to obtain experimentally, even using metamaterial design approaches. Not surprisingly, experimental demonstration of devices obtained using transformation acoustics is difficult, and has been implemented only in two-dimensional configurations. Here, we demonstrate the design and experimental characterization of an almost perfect three-dimensional, broadband, and, most importantly, omnidirectional acoustic device that renders a region of space three wavelengths in diameter invisible to sound.
Three-dimensional image reconstruction in capsule endoscopy
Koulaouzidis, Anastasios; Karargyris, Alexandros
2012-01-01
To date, limited research has been carried out in developing methods and materials that offer three-dimensional (3-D) representation of the digestive tract. In the field of capsule endoscopy (CE), hardware approaches have been developed that provide real time both 3-D information and texture using an infrared projector and a complementary metal oxide semiconductor camera. The major drawbacks of this system are its size, power consumption and packaging issues. A software approach to approximate a 3-D representation of digestive tract surface utilising current CE technology has been proposed. The algorithm utilizes the Shape from Shading technique and seem to provide promising results for polypoid structures and angioectasias. Further clinical evaluation is currently under way. PMID:22919239
Three-dimensional MHD analysis of heliotron plasma with RMP
Ichiguchi, K.; Suzuki, Y.; Sato, M.; Todo, Y.; Nicolas, T.; Sakakibara, S.; Ohdachi, S.; Narushima, Y.; Carreras, B. A.
2015-07-01
The interaction between pressure driven modes and magnetic islands generated by a resonant magnetic perturbation (RMP) in the large helical device (LHD) is numerically analyzed. In this analysis, three-dimensional treatment is essential in the equilibrium and dynamics calculations, because the equilibrium pressure profile is deformed by the RMP. The deformation changes the linear mode structure from the interchange type to the ballooning-like type that is localized around the X-point of the island in the equilibrium magnetic field including the RMP. This mode causes a pressure collapse in the nonlinear evolution, which spreads from the X-point to the core. Therefore, the spatial phase of the collapse is fixed to the island geometry. The fixed phase agrees with the LHD experimental results with a natural error field.
Three-Dimensional Printing of Prosthetic Hands for Children.
Burn, Matthew B; Ta, Anderson; Gogola, Gloria R
2016-05-01
Children with hand reductions, whether congenital or traumatic, have unique prosthetic needs. They present a challenge because of their continually changing size due to physical growth as well as changing needs due to psychosocial development. Conventional prosthetics are becoming more technologically advanced and increasingly complex. Although these are welcome advances for adults, the concomitant increases in weight, moving parts, and cost are not beneficial for children. Pediatric prosthetic needs may be better met with simpler solutions. Three-dimensional printing can be used to fabricate rugged, light-weight, easily replaceable, and very low cost assistive hands for children. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.
The computation of three-dimensional flows using unstructured grids
Morgan, K.; Peraire, J.; Peiro, J.; Hassan, O.
1991-01-01
A general method is described for automatically discretizing, into unstructured assemblies of tetrahedra, the three-dimensional solution domains of complex shape which are of interest in practical computational aerodynamics. An algorithm for the solution of the compressible Euler equations which can be implemented on such general unstructured tetrahedral grids is described. This is an explicit cell-vertex scheme which follows a general Taylor-Galerkin philosophy. The approach is employed to compute a transonic inviscid flow over a standard wing and the results are shown to compare favorably with experimental observations. As a more practical demonstration, the method is then applied to the analysis of inviscid flow over a complete modern fighter configuration. The effect of using mesh adaptivity is illustrated when the method is applied to the solution of high speed flow in an engine inlet.
Three-dimensional imaging of atomic four-body processes
Schulz, M; Fischer, D; Kollmus, H; Madison, D H; Jones, S; Ullrich, J
2003-01-01
To understand the physical processes that occur in nature we need to obtain a solid concept about the 'fundamental' forces acting between pairs of elementary particles. it is also necessary to describe the temporal and spatial evolution of many mutually interacting particles under the influence of these forces. This latter step, known as the few-body problem, remains an important unsolved problem in physics. Experiments involving atomic collisions represent a useful testing ground for studying the few-body problem. For the single ionization of a helium atom by charged particle impact, kinematically complete experiments have been performed since 1969. The theoretical analysis of such experiments was thought to yield a complete picture of the basic features of the collision process, at least for large collision energies. These conclusions are, however, almost exclusively based on studies of restricted electron-emission geometries. We report three- dimensional images of the complete electron emission pattern for...
Three-dimensional dynamic functional mapping of cardiac mechanics
Taratorin, Alexander M.; Sideman, Samuel; Beyar, R.
1993-07-01
The heart is an organ which functions by a periodic change of the three dimensional (3D) spatially distributed parameters; malfunctions of the heart's operating systems are manifested by changes of the spatio-temporal heart shape dynamics. This paper attempts to present a set of image analysis tools aimed at a thorough study of the left ventricular (LV) shape-function relationship based on Cine-CT data. Data processing methodologies aimed at analysis and interpretation of the dynamic 3D LV shape, thickening and motion are described. These include the computerized detection of the LV boundaries, dynamic reconstruction of 3D LV shape, the LV shape parameters and their spatio-temporal evolution. The procedures are demonstrated using Cine-CT images of the human LV is normal and pathological cases.
Anthropomorphic classification using three-dimensional Fourier descriptor
Lee, Nahm S.; Park, Kyung S.
1991-07-01
This paper presents an objective somatotyping method based upon a three-dimensional Fourier descriptor (FD3) as an invariant body shape descriptor. Human body shape was assumed as a stack of cross-sectional contours, and shape features were extracted based upon the FD3. The FD3 represents the shape features on the spatial frequency domain. Because global shape features are concentrated on the lower frequency terms, it is possible to classify the body shape efficiently. Trunks of forty-eight male subjects were measured using laser range finding and image processing techniques, and FD3s were calculated from their trunk contours and classified using a hierarchical clustering algorithm using Euclidian distance metric. Clustering results were compared with the classical somatotyping and showed good correlation with visual classification.
Three-dimensional printing of tissue phantoms for biophotonic imaging.
Wang, Jianting; Coburn, James; Liang, Chia-Pin; Woolsey, Nicholas; Ramella-Roman, Jessica C; Chen, Yu; Pfefer, T Joshua
2014-05-15
We have investigated the potential of tissue phantoms fabricated with thermosoftening- and photopolymerization-based three-dimensional (3D) printers for use in evaluation of biophotonic imaging systems. The optical properties of printed polymer samples were measured and compared to biological tissues. Phantoms with subsurface channels as small as 0.2 mm in diameter were fabricated and imaged with microscopy, x-ray microtomography, and optical coherence tomography to characterize morphology. These phantoms were then implemented to evaluate the penetration depth of a hyperspectral reflectance imaging system used in conjunction with a near-infrared contrast agent. Results indicated that 3D printing may provide a suitable platform for performance testing in biophotonics, although subsurface imaging is critical to mitigate printer-to-printer variability in matrix homogeneity and feature microstructure.
Three-dimensional spatial grouping affects estimates of the illuminant.
Perkins, Kenneth R; Schirillo, James A
2003-12-01
The brightnesses (i.e., perceived luminance) of surfaces within a three-dimensional scene are contingent on both the luminances and the spatial arrangement of the surfaces. Observers viewed a CRT through a haploscope that presented simulated achromatic surfaces in three dimensions. They set a test patch to be approximately 33% more intense than a comparison patch to match the comparison patch in brightness, which is consistent with viewing a real scene with a simple lightning interpretation from which to estimate a different level of illumination in each depth plane. Randomly positioning each surface in either depth plane minimized any simple lighting interpretation, concomitantly reducing brightness differences to approximately 8.5%, although the immediate surrounds of the test and comparison patches continued to differ by a 5:1 luminance ratio.
Three-dimensional global fluid simulations of cylindrical magnetized plasmas
DEFF Research Database (Denmark)
Naulin, Volker; Windisch, T.; Grulke, O.
2008-01-01
and sinks. The traditional scale separation paradigm is not applied in the simulation model to account for the important evolution of the background profiles due to the dynamics of turbulent fluctuations. Furthermore, the fluid modeling of sheath boundary conditions, which determine the plasma conditions......Plasma dynamics in cylindrical geometry, with many well diagnosed experiments in operation worldwide, is of fundamental interest. These linear machines can provide an unique testing ground for direct and detailed comparisons of numerical simulations of nonlinear plasma dynamics with experiments....... Thus, it is possible to assess the reproductive and predictive capabilities of plasma simulations in unprecedented detail. Here, three-dimensional global fluid simulations of a cylindrical magnetized plasma are presented. This plasma is characterized by the existence of spatially localized sources...
Preparation of a Three-Dimensional Full Thickness Skin Equivalent.
Reuter, Christian; Walles, Heike; Groeber, Florian
2017-01-01
In vitro test systems are a promising alternative to animal models. Due to the use of human cells in a three-dimensional arrangement that allows cell-cell or cell-matrix interactions these models may be more predictive for the human situation compared to animal models or two-dimensional cell culture systems. Especially for dermatological research, skin models such as epidermal or full-thickness skin equivalents (FTSE) are used for different applications. Although epidermal models provide highly standardized conditions for risk assessment, FTSE facilitate a cellular crosstalk between the dermal and epidermal layer and thus can be used as more complex models for the investigation of processes such as wound healing, skin development, or infectious diseases. In this chapter, we describe the generation and culture of an FTSE, based on a collagen type I matrix and provide troubleshooting tips for commonly encountered technical problems.
Surface color perception in three-dimensional scenes.
Boyaci, Huseyin; Doerschner, Katja; Snyder, Jacqueline L; Maloney, Laurence T
2006-01-01
Researchers studying surface color perception have typically used stimuli that consist of a small number of matte patches (real or simulated) embedded in a plane perpendicular to the line of sight (a "Mondrian," Land & McCann, 1971). Reliable estimation of the color of a matte surface is a difficult if not impossible computational problem in such limited scenes (Maloney, 1999). In more realistic, three-dimensional scenes the difficulty of the problem increases, in part, because the effective illumination incident on the surface (the light field) now depends on surface orientation and location. We review recent work in multiple laboratories that examines (1) the degree to which the human visual system discounts the light field in judging matte surface lightness and color and (2) what illuminant cues the visual system uses in estimating the flow of light in a scene.
Validation of three-dimensional micro injection molding simulation accuracy
DEFF Research Database (Denmark)
Tosello, Guido; Costa, F.S.; Hansen, Hans Nørgaard
2011-01-01
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...... 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...
Three-dimensional virtual environments for blind children.
Sánchez, Jaime; Sáenz, Mauricio
2006-04-01
Information technologies are increasingly helping to integrate and socially include people with visual disabilities. Computing technologies have contributed grandly to attain this goal through innovative techniques and applications. Virtual environments, I/O interfaces, and sound based applications altogether with usability and cognitive impact studies are some of the most used research designs for children with visual disabilities. This study presents the design and usability evaluation of three-dimensional (3D) interactive environments for children with visual disabilities. We introduce AudioChile and AudioVida, interactive virtual environments that can be navigated through 3D sound to enhance spatiality and immersion throughout the environments 3D sound is used to orientate, to avoid obstacles, and to identify the position of diverse personages and objects within the environment. Usability evaluation results indicated that sound can be fundamental for attention and motivation purposes during interaction.
Visualising very large phylogenetic trees in three dimensional hyperbolic space
Directory of Open Access Journals (Sweden)
Liberles David A
2004-04-01
Full Text Available Abstract Background Common existing phylogenetic tree visualisation tools are not able to display readable trees with more than a few thousand nodes. These existing methodologies are based in two dimensional space. Results We introduce the idea of visualising phylogenetic trees in three dimensional hyperbolic space with the Walrus graph visualisation tool and have developed a conversion tool that enables the conversion of standard phylogenetic tree formats to Walrus' format. With Walrus, it becomes possible to visualise and navigate phylogenetic trees with more than 100,000 nodes. Conclusion Walrus enables desktop visualisation of very large phylogenetic trees in 3 dimensional hyperbolic space. This application is potentially useful for visualisation of the tree of life and for functional genomics derivatives, like The Adaptive Evolution Database (TAED.
Three-dimensional numerical simulation during laser processing of CFRP
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.
Three-dimensional particle tracking velocimetry using dynamic vision sensors
Borer, D.; Delbruck, T.; Rösgen, T.
2017-12-01
A fast-flow visualization method is presented based on tracking neutrally buoyant soap bubbles with a set of neuromorphic cameras. The "dynamic vision sensors" register only the changes in brightness with very low latency, capturing fast processes at a low data rate. The data consist of a stream of asynchronous events, each encoding the corresponding pixel position, the time instant of the event and the sign of the change in logarithmic intensity. The work uses three such synchronized cameras to perform 3D particle tracking in a medium sized wind tunnel. The data analysis relies on Kalman filters to associate the asynchronous events with individual tracers and to reconstruct the three-dimensional path and velocity based on calibrated sensor information.
Three-dimensional hierarchical Te-Si nanostructures.
Lim, Jae-Hong; Shin, Gyeong-Jin; Hwang, Tae-Yeon; Lim, Hyo-Ryoung; Lee, Young-In; Lee, Kyu-Hwan; Kim, Sung-Dae; Oh, Min-Wook; Park, Su-Dong; Myung, Nosang V; Choa, Yong-Ho
2014-10-21
Three-dimensional hybrid nanostructures (i.e., Te "nanobranches" on a Si "nanotrunk" or Te "nanoleaves" on a Si "nanotrunk") were synthesized by combining the gold-assisted chemical etching of Si to form Si "nanotrunks" and the galvanic displacement of Si to form Te "nanobranches" or "nanoleaves." By adjusting the composition of the electrolyte used for the galvanic displacement reaction, the shape of the Te nanostructures could be changed from nanoleaves to nanobranches. The Si nanotrunks with Te nanobranches showed stronger luminescent emission in the visible region, with their Raman spectrum having a higher wave number, owing to their grain size being larger. This suggested that the optical and photoelectrochemical properties of Te-Si hybrid nanostructures depend on their shape and size. Using this approach, it should be possible to fabricate various hierarchical nanostructures for use in photoelectronic and photoelectrochemical devices.
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....
Three-dimensional periodic dielectric structures having photonic Dirac points
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.
Augmented reality three-dimensional display with light field fusion.
Xie, Songlin; Wang, Peng; Sang, Xinzhu; Li, Chengyu
2016-05-30
A video see-through augmented reality three-dimensional display method is presented. The system that is used for dense viewpoint augmented reality presentation fuses the light fields of the real scene and the virtual model naturally. Inherently benefiting from the rich information of the light field, depth sense and occlusion can be handled under no priori depth information of the real scene. A series of processes are proposed to optimize the augmented reality performance. Experimental results show that the reconstructed fused 3D light field on the autostereoscopic display is well presented. The virtual model is naturally integrated into the real scene with a consistence between binocular parallax and monocular depth cues.
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...... was analyzed in both superior and inferior maxillary repositioning. In addition, transverse surgical expansion was compared with the postsurgical expansion obtained. An overall, high degree of linear accuracy between planned and postsurgical outcomes was found, but with a large standard deviation. Rotational...
Universal dynamic scaling in three-dimensional Ising spin glasses.
Liu, Cheng-Wei; Polkovnikov, Anatoli; Sandvik, Anders W; Young, A P
2015-08-01
We use a nonequilibrium Monte Carlo simulation method and dynamical scaling to study the phase transition in three-dimensional Ising spin glasses. The transition point is repeatedly approached at finite velocity v (temperature change versus time) in Monte Carlo simulations starting at a high temperature. This approach has the advantage that the equilibrium limit does not have to be strictly reached for a scaling analysis to yield critical exponents. For the dynamic exponent we obtain z=5.85(9) for bimodal couplings distribution and z=6.00(10) for the Gaussian case. Assuming universal dynamic scaling, we combine the two results and obtain z=5.93±0.07 for generic 3D Ising spin glasses.
DNA Origami with Complex Curvatures in Three-Dimensional Space
Energy Technology Data Exchange (ETDEWEB)
Han, Dongran; Pal, Suchetan; Nangreave, Jeanette; Deng, Zhengtao; Liu, Yan; Yan, Hao
2011-04-14
We present a strategy to design and construct self-assembling DNA nanostructures that define intricate curved surfaces in three-dimensional (3D) space using the DNA origami folding technique. Double-helical DNA is bent to follow the rounded contours of the target object, and potential strand crossovers are subsequently identified. Concentric rings of DNA are used to generate in-plane curvature, constrained to 2D by rationally designed geometries and crossover networks. Out-of-plane curvature is introduced by adjusting the particular position and pattern of crossovers between adjacent DNA double helices, whose conformation often deviates from the natural, B-form twist density. A series of DNA nanostructures with high curvature—such as 2D arrangements of concentric rings and 3D spherical shells, ellipsoidal shells, and a nanoflask—were assembled.
Three-dimensional imaging of biological cells with picosecond ultrasonics
Danworaphong, Sorasak; Tomoda, Motonobu; Matsumoto, Yuki; Matsuda, Osamu; Ohashi, Toshiro; Watanabe, Hiromu; Nagayama, Masafumi; Gohara, Kazutoshi; Otsuka, Paul H.; Wright, Oliver B.
2015-04-01
We use picosecond ultrasonics to image animal cells in vitro—a bovine aortic endothelial cell and a mouse adipose cell—fixed to Ti-coated sapphire. Tightly focused ultrashort laser pulses generate and detect GHz acoustic pulses, allowing three-dimensional imaging (x, y, and t) of the ultrasonic propagation in the cells with ˜1 μm lateral and ˜150 nm depth resolutions. Time-frequency representations of the continuous-wavelet-transform amplitude of the optical reflectivity variations inside and outside the cells show GHz Brillouin oscillations, allowing the average sound velocities of the cells and their ultrasonic attenuation to be obtained as well as the average bulk moduli.
Three-dimensional structures self-assembled from DNA bricks.
Ke, Yonggang; Ong, Luvena L; Shih, William M; Yin, Peng
2012-11-30
We describe a simple and robust method to construct complex three-dimensional (3D) structures by using short synthetic DNA strands that we call "DNA bricks." In one-step annealing reactions, bricks with hundreds of distinct sequences self-assemble into prescribed 3D shapes. Each 32-nucleotide brick is a modular component; it binds to four local neighbors and can be removed or added independently. Each 8-base pair interaction between bricks defines a voxel with dimensions of 2.5 by 2.5 by 2.7 nanometers, and a master brick collection defines a "molecular canvas" with dimensions of 10 by 10 by 10 voxels. By selecting subsets of bricks from this canvas, we constructed a panel of 102 distinct shapes exhibiting sophisticated surface features, as well as intricate interior cavities and tunnels.
Three Dimensional Display Of Tumors Via Computed Tomography
Smathers, Ralph L.
1985-09-01
Computed tomography is widely utilized for the detection and staging of neoplasm. Typical chest, abdomen or pelvis CT scans may produce 10 to 20 transverse slices for each region. The mental reconstruction of the three dimensional anatomy from these transverse sections can be done by a physician who has had training in the analysis and interpretation of cross sectional anatomy and pathology. This mental reconstruction, however, may take years to develop into an efficient tool. With the 3-D reconstructions used in this study, diagnostic information concerning the location, shape and spread of tumor masses can be presented in a simple, intuitive 3-dimensional display. This technique has been found to be useful for improving communication between diagnostic radiologists and consulting physicians.
Inner mechanics of three-dimensional black holes.
Detournay, Stéphane
2012-07-20
We investigate properties of the inner horizons of certain black holes in higher-derivative three-dimensional gravity theories. We focus on Bañados-Teitelboim-Zanelli and spacelike warped anti-de Sitter black holes, as well as on asymptotically warped de Sitter solutions exhibiting both a cosmological and a black hole horizon. We verify that a first law is satisfied at the inner horizon, in agreement with the proposal of Castro and Rodriguez [arXiv:1204.1284]. We then show that, in topologically massive gravity, the product of the areas of the inner and outer horizons fails to be independent on the mass, and we trace this to the diffeomorphism anomaly of the theory.
Curved singular beams for three-dimensional particle manipulation.
Zhao, Juanying; Chremmos, Ioannis D; Song, Daohong; Christodoulides, Demetrios N; Efremidis, Nikolaos K; Chen, Zhigang
2015-07-13
For decades, singular beams carrying angular momentum have been a topic of considerable interest. Their intriguing applications are ubiquitous in a variety of fields, ranging from optical manipulation to photon entanglement, and from microscopy and coronagraphy to free-space communications, detection of rotating black holes, and even relativistic electrons and strong-field physics. In most applications, however, singular beams travel naturally along a straight line, expanding during linear propagation or breaking up in nonlinear media. Here, we design and demonstrate diffraction-resisting singular beams that travel along arbitrary trajectories in space. These curved beams not only maintain an invariant dark "hole" in the center but also preserve their angular momentum, exhibiting combined features of optical vortex, Bessel, and Airy beams. Furthermore, we observe three-dimensional spiraling of microparticles driven by such fine-shaped dynamical beams. Our findings may open up new avenues for shaped light in various applications.
Engineering Three-dimensional Epithelial Tissues Embedded within Extracellular Matrix.
Piotrowski-Daspit, Alexandra S; Nelson, Celeste M
2016-07-10
The architecture of branched organs such as the lungs, kidneys, and mammary glands arises through the developmental process of branching morphogenesis, which is regulated by a variety of soluble and physical signals in the microenvironment. Described here is a method created to study the process of branching morphogenesis by forming engineered three-dimensional (3D) epithelial tissues of defined shape and size that are completely embedded within an extracellular matrix (ECM). This method enables the formation of arrays of identical tissues and enables the control of a variety of environmental factors, including tissue geometry, spacing, and ECM composition. This method can also be combined with widely used techniques such as traction force microscopy (TFM) to gain more information about the interactions between cells and their surrounding ECM. The protocol can be used to investigate a variety of cell and tissue processes beyond branching morphogenesis, including cancer invasion.
A Three-Dimensional Cooperative Guidance Law of Multimissile System
Directory of Open Access Journals (Sweden)
Xing Wei
2015-01-01
Full Text Available In order to conduct saturation attacks on a static target, the cooperative guidance problem of multimissile system is researched. A three-dimensional guidance model is built using vector calculation and the classic proportional navigation guidance (PNG law is extended to three dimensions. Based on this guidance law, a distributed cooperative guidance strategy is proposed and a consensus protocol is designed to coordinate the time-to-go commands of all missiles. Then an expert system, which contains two extreme learning machines (ELM, is developed to regulate the local proportional coefficient of each missile according to the command. All missiles can arrive at the target simultaneously under the assumption that the multimissile network is connected. A simulation scenario is given to demonstrate the validity of the proposed method.
Logistics of Three-dimensional Printing: Primer for Radiologists.
Hodgdon, Taryn; Danrad, Raman; Patel, Midhir J; Smith, Stacy E; Richardson, Michael L; Ballard, David H; Ali, Sayed; Trace, Anthony Paul; DeBenedectis, Carolynn M; Zygmont, Matthew E; Lenchik, Leon; Decker, Summer J
2018-01-01
The Association of University Radiologists Radiology Research Alliance Task Force on three-dimensional (3D) printing presents a review of the logistic considerations for establishing a clinical service using this new technology, specifically focused on implications for radiology. Specific topics include printer selection for 3D printing, software selection, creating a 3D model for printing, providing a 3D printing service, research directions, and opportunities for radiologists to be involved in 3D printing. A thorough understanding of the technology and its capabilities is necessary as the field of 3D printing continues to grow. Radiologists are in the unique position to guide this emerging technology and its use in the clinical arena. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.
Three-dimensional structure of brain tissue at submicrometer resolution
Energy Technology Data Exchange (ETDEWEB)
Saiga, Rino; Mizutani, Ryuta, E-mail: ryuta@tokai-u.jp [Department of Applied Biochemistry, Tokai University, Hiratsuka, Kanagawa 259-1292 (Japan); Inomoto, Chie; Takekoshi, Susumu; Nakamura, Naoya; Tsuboi, Akio; Osawa, Motoki [Tokai University School of Medicine, Isehara, Kanagawa 259-1193 (Japan); Arai, Makoto; Oshima, Kenichi; Itokawa, Masanari [Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8506 (Japan); Uesugi, Kentaro; Takeuchi, Akihisa; Terada, Yasuko; Suzuki, Yoshio [Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Sayo, Hyogo 679-5198 (Japan)
2016-01-28
Biological objects are composed of submicrometer structures such as cells and organelles that are essential for their functions. Here, we report on three-dimensional X-ray visualization of cells and organelles at resolutions up to 100 nm by imaging microtomography (micro-CT) equipped with Fresnel zone plate optics. Human cerebral tissue, fruit fly cephalic ganglia, and Escherichia coli bacteria labeled with high atomic-number elements were embedded in epoxy resin and subjected to X-ray microtomography at the BL37XU and BL47XU beamlines of the SPring-8 synchrotron radiation facility. The obtained results indicated that soft tissue structures can be visualized with the imaging microtomography.
Three-dimensional structural characterization of nonwoven fabrics.
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.
Three-dimensional flow around a hovering hummingbird
Song, Jialei; Luo, Haoxiang; Hedrick, Tyson
2012-11-01
We use an immersed-boundary method to simulate the complex three-dimensional flow around a hovering hummingbird and study the unsteady vortical structures in the flow. In the simulation, the realistic wing kinematics is reconstructed from high-speed imaging data of a Rufous hummingbird, and thus the wing surface does not assume a two-dimensional plane. The Reynolds number is approximately 3000 based on the average wing-tip velocity and the mean cord length. More than 16 million Cartesian mesh points are used in the simulation, which allows us to capture both near- and far-field vortices. We will show the detailed flow structures in the presentation and will compare the numerical result with previous experimental measurement. In addition, we will discuss the force characteristics and the aerodynamic power of the bird. Supported by NSF (No. CBET-0954381).
[A three-dimensional transrectal ultrasound imaging system].
Chen, Yimin; Qi, Jian; Ding, Mingyue; Zhang, Xuming
2014-08-01
A three-dimensional (3D) transrectal ultrasound (TRUS) imaging system is presented in this paper. The 3D imaging system is used for diagnosing diseases of prostate. The 3D image is reconstructed by a series of two-dimensional image data which is obtained through rectum. It can be a guide to prostate needle biopsies. The system is built by two parts: hardware and software. In the hardware, the mechanical device, stepper motor, control circuit, B Mode TRUS and personal computer (PC) workshop are presented. The software includes the firmware of micro control unit and software of the PC workshop. In order to evaluate the performance of the 3D imaging system, we did experiments with water and agar phantoms, and the results demonstrated the system's ability of 3D imaging with high-precision.
Three-dimensional isotropic metamaterial consisting of domain-structure
Gong, Boyi; Zhao, Xiaopeng
2012-03-01
Whether an artificially designed negative-index structure could be regarded as a homogeneous medium or not rests with the ratio of its structural unit (man-made atom) over the operation wavelength. However, this definition is ambiguous, and usually the ratio is too large to rigorously meet the effective medium theory. In this paper a three-dimensional (3D) isotropic structure is presented which is obtained from a two-dimensional (2D) isotropic structure rotating on its axis for a circle, and the material is silver. Numerical studies confirm that both the 2D and 3D structures can realize a negative refractive index at microwave wavelengths. Observing the monitored surface current distributions and analogizing the molecular current and the magnetic domain, we suggest a new concept of domain-structure to explain the interior structure of this metamaterial, and finally conclude that the 3D structure is a kind of domain-structured and isotropic metamaterial.
Moving through three-dimensional phase diagrams of monoclonal antibodies.
Rakel, Natalie; Baum, Miriam; Hubbuch, Jürgen
2014-01-01
Protein phase behavior characterization is a multivariate problem due to the high amount of influencing parameters and the diversity of the proteins. Single influences on the protein are not understood and fundamental knowledge remains to be obtained. For this purpose, a systematic screening method was developed to characterize the influence of fluid phase conditions on the phase behavior of proteins in three-dimensional phase diagrams. This approach was applied to three monoclonal antibodies to investigate influences of pH, protein and salt concentrations, with five different salts being tested. Although differences exist between the antibodies, this extensive study confirmed the general applicability of the Hofmeister series over the broad parameter range analyzed. The influence of the different salts on the aggregation (crystallization and precipitation) probability was described qualitatively using this Hofmeister series, with a differentiation between crystallization and precipitation being impossible, however. © 2014 American Institute of Chemical Engineers.
Hysteretic behavior in three-dimensional soap film rearrangements.
Vandewalle, N; Noirhomme, M; Schockmel, J; Mersch, E; Lumay, G; Terwagne, D; Dorbolo, S
2011-02-01
We report experiments on soap film configurations in a triangular prism for which the shape factor can be changed continuously. Two stable configurations can be observed for a range of the shape factor h, being the prism-height/edge-length ratio. A hysteretic behavior is found, due to the occurrence of another local minima in the free energy. Contrary to a common belief, soap films can be trapped in a particular configuration being different from a global surface minimization. This metastability can be evidenced from a geometrical model based on idealized structures. Depending on the configuration, the transition is either first or second order, providing clues on the structural relaxations taking place into three-dimensional foams, such as T1 rearrangements.
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.
Real time three-dimensional echocardiography and endovascular stenting.
Abusaid, Ghassan H; Cheema, Omar M; Xie, Tianrong; Mercado-Young, Rosario A; Ahmad, Masood
2012-09-01
A 52-year-old male with HIV and chronic renal failure presented with 2-day history of fever and chills. He had recent superior vena cava (SVC) stent placement for SVC stenosis following multiple dialysis-catheter insertions. Patient's blood cultures grew methicillin-resistant staphylococcus aureus. Two-dimensional (2D) echocardiography showed no vegetations. With high clinical suspicion, 2D transesophageal echocardiogram (TEE) was obtained and confirmed no endocarditis and patent stent at SVC right atrial junction; however, entire stent was not visualized. Simultaneous three-dimensional TEE provided superior views of SVC stent in cross-sectional and longitudinal planes, clearly demonstrating patent stent without vegetations, stenosis, migration, or thrombosis. © 2012, Wiley Periodicals, Inc.
Three-dimensional characterization of stress corrosion cracks
Energy Technology Data Exchange (ETDEWEB)
Lozano-Perez, S., E-mail: sergio.lozano-perez@materials.ox.ac.u [University of Oxford, Department of Materials, Parks Road, Oxford OX1 3PH (United Kingdom); Rodrigo, P. [Universidad Rey Juan Carlos, Dpto. de Ciencia e Ingenieria de Materiales, c/ Tulipan s.n., 28933 Mostoles (Madrid) (Spain); Gontard, Lionel C. [Danish Technical University, Center for Electron Nanoscopy, Matematiktorvet Building 307, Room 115, 2800 Kogens Lyngby (Denmark)
2011-01-31
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 this problem, different approaches to extract 3D information have been used in the recent years. In this work we will present the benefits of using 3D focused ion beam (FIB) slicing and electron tomography. 3D FIB slicing offers a fast and high throughput characterization while electron tomography offers 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 to the strain direction and grain boundary plane accurately measured.
Three-dimensional reconstruction for high-speed volume measurement
Lee, Dah-Jye; Lane, Robert M.; Chang, Guang-Hwa
2001-02-01
Volume measurement is an important process for various industries such as food processing, fruit and vegetable grading, etc. Value or price is often determined by the size of product. In seafood industry, for example, oyster meat is separated into four grades before being packaged. Large size grade means higher selling price than small size. More consistent packaging size is also an indication of high quality. Product size can be measured optically with machine vision technology for on-line inspection and grading systems. Most optical grading techniques use a two-dimensional area projection or the weight of the product to estimate the actual product volume. These methods are subject to measurement inaccuracy because of the missing thickness information. An algorithm combines laser triangulation technique with two-dimensional measurement to reconstruct a three-dimensional surface for volume measurement is introduced in this paper. The result of this technique shows a significant accuracy improvement from the area-projection method
Three-dimensional computed tomography of the acetabulum
Energy Technology Data Exchange (ETDEWEB)
Pozzi Mucelli, R.S.; Muner, G.; Pozzi Mucelli, F.; Pozzi Mucelli, M.; Marotti, F.; Dalla Palma, L.
1986-08-01
Acetabular fractures represent a complex variety that are classified in different types. Conventional radiology is often inadequate to demonstrate and classify the fractures. Computed tomography (CT) has already been shown to be superior in this field. A further advantage of CT is represented by the recent availability of three-dimensional (3D) images that are realized from axial CT scans by means of a new software. The Authors report the applications of this new software to the study of the normal acetabulum and in patients with fractures. 3D images allows an effective demonstration of the fracture, its irradiation and the dislocation of bone fragments. The information is contained in one or few images rather than many axial images. Therefore the role of 3D images may be considered complementary to axial CT scans.
Engineering three-dimensional cell mechanical microenvironment with hydrogels.
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.
Higher derivative terms in three dimensional supersymmetric theories
Energy Technology Data Exchange (ETDEWEB)
Awad, Adel [Center for Theoretical Physics, British University of Egypt,Sherouk City 11837, P.O. Box 43 (Egypt); Department of Physics, Faculty of Science,Ain Shams University, Abbassia, Cairo 11566 (Egypt); Faizal, Mir [Department of Physics and Astronomy, University of Waterloo,Waterloo, Ontario N2L 3G1 (Canada)
2015-10-01
In this work, we systematically analyze higher derivative terms in the supersymmetric effective actions for three dimensional scalar field theories using N=1 superspace formalism. In these effective actions, we show that auxiliary fields do not propagate and their effective actions can be expressed in terms of the physical fields. So, the theory does not change its field content upon addition of higher derivative terms. We use derivative expansion to generate four, five and six dimensional terms for an interacting scalar field theory with N=1 supersymmetry. We show that along with pure fermionic and bosonic terms, there are various five and six dimensional topological terms that mix bosonic and fermionic fields. Finally, we use these results to obtain higher derivative topological terms in the effective action for two M2-branes.
Three dimensional simulation for bayou choctaw strategic petroleum reserve (SPR).
Energy Technology Data Exchange (ETDEWEB)
Ehgartner, Brian L. (Sandia National Laboratories, Albuquerque, NM); Park, Byoung Yoon; Lee, Moo Yul
2006-12-01
Three dimensional finite element analyses were performed to evaluate the structural integrity of the caverns located at the Bayou Choctaw (BC) site which is considered a candidate for expansion. Fifteen active and nine abandoned caverns exist at BC, with a total cavern volume of some 164 MMB. A 3D model allowing control of each cavern individually was constructed because the location and depth of caverns and the date of excavation are irregular. The total cavern volume has practical interest, as this void space affects total creep closure in the BC salt mass. Operations including both cavern workover, where wellhead pressures are temporarily reduced to atmospheric, and cavern enlargement due to leaching during oil drawdowns that use water to displace the oil from the caverns, were modeled to account for as many as the five future oil drawdowns in the six SPR caverns. The impacts on cavern stability, underground creep closure, surface subsidence, infrastructure, and well integrity were quantified.
GPS based three-dimensional ionospheric monitoring: procedure and assessment
Stolle, C.; Schlüter, S.; Heise, S.; Jacobi, Ch.; Jakowski, N.; Raabe, A.
Integrated TEC measurements derived from ground- and space-based GPS observations are used to image the ionospheric electron density distribution through three-dimensional tomographic reconstruction. Here, the reconstruction procedure is presented, that has been applied for ionospheric mapping especially during perturbed geomagnetic conditions. The monitoring technique including tomographic algorithm and external constraints is described and discussed in detail. The procedure is based on an iterative MART algorithm and is initialised by a combined IRI/GCPM model. Input data are GPS TEC measured from ground-based networks as well as from the scientific Low Earth Orbiting (LEO) satellite CHAMP. The problem of spaceborne GPS instrumental biases is addressed, and the approach applied for bias estimation by using calibrated zenith antenna TEC data is presented. Statistical validations of tomographic results with independent data are shown.
Three-dimensional analysis of tokamaks and stellarators.
Garabedian, Paul R
2008-09-16
The NSTAB equilibrium and stability code and the TRAN Monte Carlo transport code furnish a simple but effective numerical simulation of essential features of present tokamak and stellarator experiments. When the mesh size is comparable to the island width, an accurate radial difference scheme in conservation form captures magnetic islands successfully despite a nested surface hypothesis imposed by the mathematics. Three-dimensional asymmetries in bifurcated numerical solutions of the axially symmetric tokamak problem are relevant to the observation of unstable neoclassical tearing modes and edge localized modes in experiments. Islands in compact stellarators with quasiaxial symmetry are easier to control, so these configurations will become good candidates for magnetic fusion if difficulties with safety and stability are encountered in the International Thermonuclear Experimental Reactor (ITER) project.
Three-dimensional analysis of tokamaks and stellarators
Garabedian, Paul R.
2008-01-01
The NSTAB equilibrium and stability code and the TRAN Monte Carlo transport code furnish a simple but effective numerical simulation of essential features of present tokamak and stellarator experiments. When the mesh size is comparable to the island width, an accurate radial difference scheme in conservation form captures magnetic islands successfully despite a nested surface hypothesis imposed by the mathematics. Three-dimensional asymmetries in bifurcated numerical solutions of the axially symmetric tokamak problem are relevant to the observation of unstable neoclassical tearing modes and edge localized modes in experiments. Islands in compact stellarators with quasiaxial symmetry are easier to control, so these configurations will become good candidates for magnetic fusion if difficulties with safety and stability are encountered in the International Thermonuclear Experimental Reactor (ITER) project. PMID:18768807
Three-dimensional equilibria in axially symmetric tokamaks
Garabedian, Paul R.
2006-01-01
The NSTAB and TRAN computer codes have been developed to study equilibrium, stability, and transport in fusion plasmas with three-dimensional (3D) geometry. The numerical method that is applied calculates islands in tokamaks like the Doublet III-D at General Atomic and the International Thermonuclear Experimental Reactor. When bifurcated 3D solutions are used in Monte Carlo computations of the energy confinement time, a realistic simulation of transport is obtained. The significance of finding many 3D magnetohydrodynamic equilibria in axially symmetric tokamaks needs attention because their cumulative effect may contribute to the prompt loss of α particles or to crashes and disruptions that are observed. The 3D theory predicts good performance for stellarators. PMID:17159158
Investigating the potential of three-dimensional treatment planning.
Fraass, B A
3-D treatment planning has received a great deal of attention in the radiation therapy community over the last several years. This new technology makes use of the continuous improvements in computer hardware and graphics capabilities, along with major improvements in treatment planning software, to provide a fully three dimensional simulation of the patient, radiation beams, and dose distributions which are used for radiation therapy of various cancers. With these capabilities, the physician and treatment planner may now optimize the radiation beams used to treat the patient much more effectively than in the past, when only a limited description of the patient, beams, and doses was available. This paper describes several of the new capabilities of these 3-D planning systems, some research studies which are currently being performed to evaluate the usefulness of the new technology, and finally some of the costs associated with its implementation.
In vivo Degradation of Three-Dimensional Silk Fibroin Scaffolds
Wang, Yongzhong; Rudym, Darya D.; Walsh, Ashley; Abrahamsen, Lauren; Kim, Hyeon-Joo; Kim, Hyun Suk; Kirker-Head, Carl; Kaplan, David L.
2011-01-01
Three-dimensional porous scaffolds prepared from regenerated silk fibroin using either an all aqueous process or a process involving an organic solvent, hexafluoroisopropanol (HFIP) have shown promise in cell culture and tissue engineering applications. However, their biocompatibility and in vivo degradation has not been fully established. The present study was conducted to systematically investigate how processing method (aqueous vs. organic solvent) and processing variables (silk fibroin concentration and pore size) affect the short-term (up to 2 months) and long-term (up to 1 year) in vivo behavior of the protein scaffolds in both nude and Lewis rats. The samples were analyzed by histology for scaffold morphological changes and tissue ingrowth, and by real-time RT-PCR and immunohistochemistry for immune responses. Throughout the period of implantation, all scaffolds were well-tolerated by the host animals and immune responses to the implants were mild. Most scaffolds prepared from the all aqueous process degraded to completion between two and six months, while those prepared from organic solvent (hexafluoroisopropanol (HFIP)) process persisted beyond one year. Due to widespread cellular invasion throughout the scaffold, the degradation of aqueous-derived scaffolds appears to be more homogeneous than that of HFIP-derived scaffolds. In general and especially for the HFIP-derived scaffolds, a higher original silk fibroin concentration (e.g. 17%) and smaller pore size (e.g. 100–200 µm) resulted in lower levels of tissue ingrowth and slower degradation. These results demonstrate that the in vivo behavior of the three-dimensional silk fibroin scaffolds is related to the morphological and structural features that resulted from different scaffold preparation processes. The insights gained in this study can serve as a guide for processing scenarios to match desired morphological and structural features and degradation time with tissue-specific applications. PMID
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 ^{1}H 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 ^{1}H and ^{13}C MR spectra acquired from a belemnite suggest intracrystalline water or hydroxyl groups, rather than organic residues.
In vitro measurement accuracy of three-dimensional ultrasound.
Zotz, R J; Trabold, T; Bock, A; Kollmann, C
2001-02-01
We sought to validate distance and volume measurements in three-dimensional (3-D) ultrasound images. Even with the latest equipment, it is not known how accurate 3-D echocardiographic measurements are. Six models were imaged in ethanol solution and two within a tissue phantom using a mechanical rotation device rotating in 1 degrees intervals and a real-time 3-D scanner. Distance and volume measurements (n = 60) were performed in two-dimensional (2-D) and 3-D images using TomTec and InViVo software. Distance measurements had a mean total error between 1.12% and 2.31% for Acuson (2.5 MHZ, 3 MHZ, and 4 MHZ) and Hewlett Parkard (HP) fusion frequencies h and m, HP fusion harmonic B in the axial, and between 3.5% and 4.9% in the lateral dimension. HP Harmonic A and B, Volumetrics (2.5 MHZ), and HP fusion Harmonic A exhibited significantly higher differences to reality with a mean difference between 5.1% and 8.9% in the axial and between 6.2% and 7.9% in the lateral direction. Axial 2-D measurements were not different from real dimensions except Volumetrics model 1. In the lateral axis, all imaging modalities were different from reality except the fusion harmonic modus B. Using the HP fusion frequency h and HP fusion Harmonic B-mode, volume measurements in 3-D images significantly underestimated reality, while Acuson's fundamental frequency 3.5 MHZ was not different from real volumes. Three-dimensional visualization using different ultrasound settings results in different accuracy.
Three-dimensional Si/Ge quantum dot crystals.
Grützmacher, Detlev; Fromherz, Thomas; Dais, Christian; Stangl, Julian; Müller, Elisabeth; Ekinci, Yasin; Solak, Harun H; Sigg, Hans; Lechner, Rainer T; Wintersberger, Eugen; Birner, Stefan; Holý, Vaclav; Bauer, Günther
2007-10-01
Modern nanotechnology offers routes to create new artificial materials, widening the functionality of devices in physics, chemistry, and biology. Templated self-organization has been recognized as a possible route to achieve exact positioning of quantum dots to create quantum dot arrays, molecules, and crystals. Here we employ extreme ultraviolet interference lithography (EUV-IL) at a wavelength of lambda = 13.5 nm for fast, large-area exposure of templates with perfect periodicity. Si(001) substrates have been patterned with two-dimensional hole arrays using EUV-IL and reactive ion etching. On these substrates, three-dimensionally ordered SiGe quantum dot crystals with the so far smallest quantum dot sizes and periods both in lateral and vertical directions have been grown by molecular beam epitaxy. X-ray diffractometry from a sample volume corresponding to about 3.6 x 10(7) dots and atomic force microscopy (AFM) reveal an up to now unmatched structural perfection of the quantum dot crystal and a narrow quantum dot size distribution. Intense interband photoluminescence has been observed up to room temperature, indicating a low defect density in the three-dimensional (3D) SiGe quantum dot crystals. Using the Ge concentration and dot shapes determined by X-ray and AFM measurements as input parameters for 3D band structure calculations, an excellent quantitative agreement between measured and calculated PL energies is obtained. The calculations show that the band structure of the 3D ordered quantum dot crystal is significantly modified by the artificial periodicity. A calculation of the variation of the eigenenergies based on the statistical variation in the dot dimensions as determined experimentally (+/-10% in linear dimensions) shows that the calculated electronic coupling between neighboring dots is not destroyed due to the quantum dot size variations. Thus, not only from a structural point of view but also with respect to the band structure, the 3D ordered
Three-dimensional measurement system for crime scene documentation
Adamczyk, Marcin; Hołowko, Elwira; Lech, Krzysztof; Michoński, Jakub; MÄ czkowski, Grzegorz; Bolewicki, Paweł; Januszkiewicz, Kamil; Sitnik, Robert
2017-10-01
Three dimensional measurements (such as photogrammetry, Time of Flight, Structure from Motion or Structured Light techniques) are becoming a standard in the crime scene documentation process. The usage of 3D measurement techniques provide an opportunity to prepare more insightful investigation and helps to show every trace in the context of the entire crime scene. In this paper we would like to present a hierarchical, three-dimensional measurement system that is designed for crime scenes documentation process. Our system reflects the actual standards in crime scene documentation process - it is designed to perform measurement in two stages. First stage of documentation, the most general, is prepared with a scanner with relatively low spatial resolution but also big measuring volume - it is used for the whole scene documentation. Second stage is much more detailed: high resolution but smaller size of measuring volume for areas that required more detailed approach. The documentation process is supervised by a specialised application CrimeView3D, that is a software platform for measurements management (connecting with scanners and carrying out measurements, automatic or semi-automatic data registration in the real time) and data visualisation (3D visualisation of documented scenes). It also provides a series of useful tools for forensic technicians: virtual measuring tape, searching for sources of blood spatter, virtual walk on the crime scene and many others. In this paper we present our measuring system and the developed software. We also provide an outcome from research on metrological validation of scanners that was performed according to VDI/VDE standard. We present a CrimeView3D - a software-platform that was developed to manage the crime scene documentation process. We also present an outcome from measurement sessions that were conducted on real crime scenes with cooperation with Technicians from Central Forensic Laboratory of Police.
[Three-dimensional sonoembryology--myth or reality].
Atanasova, D; Markov, D; Pavlova, E; Markov, P; Ivanov, St
2010-01-01
To describe the normal development of the embryonic central nervous system (CNS) using three-dimensional (3D) transvaginal (TV) ultrasound (US) between 7 and 10 w.g. and to compare the embryonic development visualized by 3D TV US with that of the classical embryology. A prospective longitudinal study was conducted over a period of 10 months with high-end ultrasound equipment (Voluson 730 Expert, GE Healthcare, U.S.). Thirty six pregnant women between 7 and 10 weeks of gestation (w.g.) were examined. In all cases a high-frequency 30 TV probe was used to acquire a 3D volume of the embryo, including the cranial pole. Subsequently, the acquired volume information was post-processed and analyzed with specialized software 4D View ver. 9.1 (GE Healthcare, U.S.). The duration of the examinations was about 15 minutes. Three-dimensional TV US allows adequate visualization of the embryonic CNS in accordance with the Carnegie stages from the classical embryology. In 7 w.g. it is possible to identify the diencephalon (future third ventricle), mesencephalon (future aqueductus Sylvii), rhombencephalon (future fourth ventricle), and the two hemispheres. In 8 w.g. the choroid plexus in the lateral ventricles, the fourth ventricle and the cerebellum can also be recognized. The developmental changes in the size, shape and relationship of the described structures can be progressively assessed in 9 and 10 w.g. Implementation of high-frequency 3D TV probes allows good visualization of the developing embryo, detailed anatomical description of all main cerebral structures, as well as adequate reconstruction of the brain ventricular system between 7 and 10 w.g. There is a good correlation between the embryonic development visualized by 3D TV U.S. and that of the classical embryology.
Three-Dimensional Morphology of a Coronal Prominence Cavity
Gibson, S. E.; Kucera, T. A.; Rastawicki, D.; Dove, J.; deToma, G.; Hao, J.; Hill, S.; Hudson, H. S.; Marque, C.; McIntosh, P. S.;
2010-01-01
We present a three-dimensional density model of coronal prominence cavities, and a morphological fit that has been tightly constrained by a uniquely well-observed cavity. Observations were obtained as part of an International Heliophysical Year campaign by instruments from a variety of space- and ground-based observatories, spanning wavelengths from radio to soft-X-ray to integrated white light. From these data it is clear that the prominence cavity is the limb manifestation of a longitudinally-extended polar-crown filament channel, and that the cavity is a region of low density relative to the surrounding corona. As a first step towards quantifying density and temperature from campaign spectroscopic data, we establish the three-dimensional morphology of the cavity. This is critical for taking line-of-sight projection effects into account, since cavities are not localized in the plane of the sky and the corona is optically thin. We have augmented a global coronal streamer model to include a tunnel-like cavity with elliptical cross-section and a Gaussian variation of height along the tunnel length. We have developed a semi-automated routine that fits ellipses to cross-sections of the cavity as it rotates past the solar limb, and have applied it to Extreme Ultraviolet Imager (EUVI) observations from the two Solar Terrestrial Relations Observatory (STEREO) spacecraft. This defines the morphological parameters of our model, from which we reproduce forward-modeled cavity observables. We find that cavity morphology and orientation, in combination with the viewpoints of the observing spacecraft, explains the observed variation in cavity visibility for the east vs. west limbs
Visualization of Three-Dimensional Nephron Structure With Microcomputed Tomography
Energy Technology Data Exchange (ETDEWEB)
Bentley,M.; Jorgensen, S.; Lerman, L.; Ritman, E.; Romero, J.
2007-01-01
The three-dimensional architecture of nephrons in situ and their interrelationship with other nephrons are difficult to visualize by microscopic methods. The present study uses microcomputed X-ray tomography (micro-CT) to visualize intact nephrons in situ. Rat kidneys were perfusion-fixed with buffered formalin and their vasculature was subsequently perfused with radiopaque silicone. Cortical tissue was stained en bloc with osmium tetroxide, embedded in plastic, scanned, and reconstructed at voxel resolutions of 6, 2, and 1 {mu}m. At 6 {mu}m resolution, large blood vessels and glomeruli could be visualized but nephrons and their lumens were small and difficult to visualize. Optimal images were obtained using a synchrotron radiation source at 2 {mu}m resolution where nephron components could be identified, correlated with histological sections, and traced. Proximal tubules had large diameters and opaque walls, whereas distal tubules, connecting tubules, and collecting ducts had smaller diameters and less opaque walls. Blood vessels could be distinguished from nephrons by the luminal presence of radiopaque silicone. Proximal tubules were three times longer than distal tubules. Proximal and distal tubules were tightly coiled in the outer cortex but were loosely coiled in the middle and inner cortex. The connecting tubules had the narrowest diameters of the tubules and converged to form arcades that paralleled the radial vessels as they extended to the outer cortex. These results illustrate a potential use of micro-CT to obtain three-dimensional information about nephron architecture and nephron interrelationships, which could be useful in evaluating experimental tubular hypertrophy, atrophy, and necrosis.
THREE DIMENSIONAL PRINTING IN THE SOUTH AFRICAN INDUSTRIAL ENVIRONMENT
Directory of Open Access Journals (Sweden)
D. Dimitrov
2012-01-01
Full Text Available
ENGLISH ABSTRACT: The current development of the rapid prototyping industry in South Africa is characterised by the strong dominance and fast growth in sales of three dimensional printers. Although it reflects the international trend, it seems that the industrial community lacks a clear appreciation of the real strength of this technology, especially with respect to the large variety of devices available today on the market. This paper surveys the current state and capabilities of three dimensional printing (3DP. Based on its technical background – the ink-jet printing known from the printer and plotter industry – a classification structure is developed and proposed. Different printing techniques and process concepts, together with their advantages and limitations, are described and analysed. Typical examples from three completely different application areas – manufacturing, medicine, and architecture – are presented and discussed. Some basic considerations for an informed selection of the right technology for a particular application are then presented.
AFRIKAANSE OPSOMMING: Sterk groei in die verkope van drie dimensionele drukkers (3DP kenmerk die onlangse groei in die snelle prototipe industrie in Suid-Afrika. Ten spyte daarvan dat hierdie ‘n internasionale tendens reflekteer, blyk dit dat die werklike waarde van die tegnologie nog nie ten volle waardeer word in die industriële gemeenskap nie, veral aangesien daar so ‘n groot verskeidenheid masjiene in die mark beskikbaar is. ‘n Oorsig oor die huidige stand en vermoë van drie dimensionele drukkers word hier gegee. ‘n Klassifikasiestruktuur – gebaseer op die inkspuitdrukkertegnologie – word ontwikkel en voorgestel. Verskillende druktegnieke en konsepprosesse word ontleed. Daar word ook gekyk na die voor- en nadele hiervan. Tipiese voorbeelde van drie verskillende toepassings (vervaardiging, medies, en argitektuur word aangebied en bespreek. Basiese riglyne vir
[Fetal brain fissures development a three-dimensional ultrasonography study].
Alves, Cynthia Maria Soares; Araujo Júnior, Edward; Nardozza, Luciano Marcondes Machado; Oliveira, Patrícia Soares de; Goldman, Suzan Menasce; Ajzen, Sérgio Aron; Moron, Antonio Fernandes
2011-03-01
to assess the distance of the fetal cerebral fissures from the inner edge of the skull by three-dimensional ultrasonography (3DUS). this cross-sectional study included 80 women with normal pregnancies between 21st and 34th weeks. The distances between the Sylvian, parieto-occiptal, hippocampus and calcarine fissures and the internal surface of the fetal skull were measured. For the evaluation of the distance of the first three fissures, an axial three-dimensional scan was obtained (at the level of the lateral ventricles). To obtain the calcarine fissure measurement, a coronal scan was used (at the level of the occipital lobes). First degree regressions were performed to assess the correlation between fissure measurements and gestational age, using the determination coefficient (R²) for adjustment. The 5th, 50th and 95th percentiles were calculated for each fissure measurement. Pearson's correlation coefficient (r) was used to assess the correlation between fissure measurements and the biparietal diameter (BPD) and head circumference (HC). all fissure measurements were linearly correlated with gestational age (Sylvian: R²=0.5; parieto-occiptal: R²= 0.7; hippocampus: R²= 0.3 and calcarine: R²= 0.3). Mean fissure measurement ranged from 7.0 to 14.0 mm, 15.9 to 28.7 mm, 15.4 to 25.4 mm and 15.7 to 24.8 mm for the Sylvian, parieto-occiptal, hippocampus and calcarine fissures, respectively. The Sylvian and parieto-occiptal fissure measurements had the highest correlations with the BPD (r=0.8 and 0.7, respectively) and HC (r=0.7 and 0.8, respectively). the distance from the fetal cerebral fissures to the inner edge of the skull measured by 3DUS was positively correlated with gestational age.
Symmetry enrichment in three-dimensional topological phases
Ning, Shang-Qiang; Liu, Zheng-Xin; Ye, Peng
2016-12-01
While two-dimensional symmetry-enriched topological phases (SETs ) have been studied intensively and systematically, three-dimensional ones are still open issues. We propose an algorithmic approach of imposing global symmetry Gs on gauge theories (denoted by GT) with gauge group Gg. The resulting symmetric gauge theories are dubbed "symmetry-enriched gauge theories" (SEG), which may be served as low-energy effective theories of three-dimensional symmetric topological quantum spin liquids. We focus on SEGs with gauge group Gg=ZN1×ZN2×⋯ and onsite unitary symmetry group Gs=ZK1×ZK2×⋯ or Gs=U (1 ) ×ZK 1×⋯ . Each SEG(Gg,Gs) is described in the path-integral formalism associated with certain symmetry assignment. From the path-integral expression, we propose how to physically diagnose the ground-state properties (i.e., SET orders) of SEGs in experiments of charge-loop braidings (patterns of symmetry fractionalization) and the mixed multiloop braidings among deconfined loop excitations and confined symmetry fluxes. From these symmetry-enriched properties, one can obtain the map from SEGs to SETs . By giving full dynamics to background gauge fields, SEGs may be eventually promoted to a set of new gauge theories (denoted by GT*). Based on their gauge groups, GT*s may be further regrouped into different classes, each of which is labeled by a gauge group Gg*. Finally, a web of gauge theories involving GT,SEG,SET, and GT* is achieved. We demonstrate the above symmetry-enrichment physics and the web of gauge theories through many concrete examples.
Three-dimensional lattice Boltzmann model for compressible flows.
Sun, Chenghai; Hsu, Andrew T
2003-07-01
A three-dimensional compressible lattice Boltzmann model is formulated on a cubic lattice. A very large particle-velocity set is incorporated in order to enable a greater variation in the mean velocity. Meanwhile, the support set of the equilibrium distribution has only six directions. Therefore, this model can efficiently handle flows over a wide range of Mach numbers and capture shock waves. Due to the simple form of the equilibrium distribution, the fourth-order velocity tensors are not involved in the formulation. Unlike the standard lattice Boltzmann model, no special treatment is required for the homogeneity of fourth-order velocity tensors on square lattices. The Navier-Stokes equations were recovered, using the Chapman-Enskog method from the Bhatnagar-Gross-Krook (BGK) lattice Boltzmann equation. The second-order discretization error of the fluctuation velocity in the macroscopic conservation equation was eliminated by means of a modified collision invariant. The model is suitable for both viscous and inviscid compressible flows with or without shocks. Since the present scheme deals only with the equilibrium distribution that depends only on fluid density, velocity, and internal energy, boundary conditions on curved wall are easily implemented by an extrapolation of macroscopic variables. To verify the scheme for inviscid flows, we have successfully simulated a three-dimensional shock-wave propagation in a box and a normal shock of Mach number 10 over a wedge. As an application to viscous flows, we have simulated a flat plate boundary layer flow, flow over a cylinder, and a transonic flow over a NACA0012 airfoil cascade.
DEFF Research Database (Denmark)
Sessarego, Matias; Ramos García, Néstor; Yang, Hua
2016-01-01
In this paper a surrogate optimization methodology using a three-dimensional viscous-inviscid interaction code for the aerodynamic design of wind-turbine rotors is presented. The framework presents aunique approach because it does not require the commonly-used blade element momentum (BEM)method. ......In this paper a surrogate optimization methodology using a three-dimensional viscous-inviscid interaction code for the aerodynamic design of wind-turbine rotors is presented. The framework presents aunique approach because it does not require the commonly-used blade element momentum (BEM...... performance can be achieved using the new design method and that themethodology is effective for the aerodynamic design of wind-turbine rotors....
Luo, Wen; Zhang, Pengfei; Wang, Xuanpeng; Li, Qidong; Dong, Yifan; Hua, Jingchen; Zhou, Liang; Mai, Liqiang
2016-02-01
A novel composite with antimony (Sb) nanoparticles anchored in three-dimensional carbon network (denoted as SbNPs@3D-C) is successfully synthesized via a NaCl template-assisted self-assembly strategy, followed by freeze-drying and one-step in-situ carbonization. The three-dimensional interconnected macroporous carbon framework can not only stabilize the architecture and buffer the volume expansion for Sb nanoparticles, but also provide high electrical conductivity for the whole electrode. Consequently, as a sodium-ion battery anode, the SbNPs@3D-C delivers a high reversible capacity (456 mAh g-1 at 100 mA g-1), stable cycling performance (94.3% capacity retention after 500 cycles at 100 mA g-1) as well as superior rate capability (270 mAh g-1 at 2000 mA g-1). When compared with commercial Sb particles, the SbNPs@3D-C exhibits dramatically enhanced electrochemical performance. Free from expensive template sources and complex manipulation, this work might shed some light on the synthesis of low-cost and high-performance materials for the next ;beyond lithium; battery generation.
Three-dimensional seismo-tectonics in the Po Valley basin, Northern Italy
Turrini, Claudio; Angeloni, Pamela; Lacombe, Olivier; Ponton, Maurizio; Roure, François
2015-10-01
The Po Valley (Northern Italy) is a composite foreland-foredeep basin caught in between the Southern Alps and Northern Apennine mountain belts. By integrating the 3D structural model of the region with the public earthquake dataset, the seismo-tectonics of the basin is shown at different scales of observation. The three-dimensional geo-volume is used to review the seismicity around the region and validate the structure-earthquake association for such a complex tectonic framework. Despite the overall uncertainty due to the original data distribution-quality as well as the crustal scale model dimension, the direct correlation between structures and seismicity a) confirms the Po Valley region as an active tectonic system and b) allows the whole structural architecture to be revised by a unique three-dimensional perspective and approach. This study also indicates that 3D methodology is a powerful tool for better understanding of highly complex seismo-tectonic situations at both regional and local scales.
A hybrid stochastic/deterministic method for transient, three-dimensional neutron transport
Energy Technology Data Exchange (ETDEWEB)
Waddell, M.W. Jr. (Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)); Dodds, H.L. (Univ. of Tennessee, Knoxville (United States))
1992-01-01
This paper describes the development of a method for solving the time-dependent, three-dimensional Boltzmann transport model. A hybrid stochastic/deterministic technique is utilized with a Monte Carlo code embedded inside of a quasistatic kinetics framework. The amplitude function is computed deterministically by a conventional point-kinetics algorithm. The point-kinetics parameters, reactivity and generation time, as well as the flux shape, are computed stochastically during the random walk of the Monte Carlo calculation. The code (TDKENO), which was developed based on this new method, could serve as a benchmarking tool for other more approximate and less expensive kinetics codes. It would also be useful for modeling transients of systems with complex geometries. Furthermore, three-dimensional transport theory is needed in areas such as reactor accident studies that involve coolant voiding and/or core disassembly. Preliminary results are presented in this paper. The code is applied to a standard benchmark problem, and the results are compared with another method. 7 refs., 1 fig.
Mashari, Azad; Knio, Ziyad; Yeh, Lu; Jeganathan, Jelliffe; Matyal, Robina; Khabbaz, Kamal R; Mahmood, Feroze
2016-01-01
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. PMID:27974356
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.
Secondary motion in three-dimensional branching networks.
Guha, Abhijit; Pradhan, Kaustav
2017-06-01
A major aim of the present work is to understand and thoroughly document the generation, the three-dimensional distribution, and the evolution of the secondary motion as the fluid progresses downstream through a branched network. Six generations (G0-G5) of branches (involving 63 straight portions and 31 bifurcation modules) are computed in one go; such computational challenges are rarely taken in the literature. More than 30 × 10(6) computational elements are employed for high precision of computed results and fine quality of the flow visualization diagrams. The study of co-planar vis-à-vis non-planar space-filling configurations establishes a quantitative evaluation of the dependence of the fluid dynamics on the three-dimensional arrangement of the same individual branches. As compared to the secondary motion in a simple curved pipe, three distinctive features, viz., the change of shape and size of the flow-cross-section, the division of non-uniform primary flow in a bifurcation module, and repeated switchover from clockwise to anticlockwise curvature and vice versa in the flow path, make the present situation more complex. It is shown that the straight portions in the network, in general, attenuate the secondary motion, while the three-dimensionally complex bifurcation modules generate secondary motion and may alter the number, arrangement, and structure of vortices. A comprehensive picture of the evolution of quantitative flow visualizations of the secondary motion is achieved by constructing contours of secondary velocity [Formula: see text], streamwise vorticity [Formula: see text], and [Formula: see text] iso-surfaces. It is demonstrated, for example, that for in-plane configuration, the vortices on any plane appear in pair (i.e., for each clockwise rotating vortex, there is an otherwise identical anticlockwise vortex), whereas the vortices on a plane for the out-of-plane configuration may be dissimilar, and there may even be an odd number of vortices. We
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
Three Dimensional Micro and Nano Fabrication of Metamaterials
Zhou, Fan
The concept of artificially structured metamateials arises as a promising solution to offer broad tunability of material properties. Rather than on its chemical composition, macroscopic properties of metamateirals depend on the hierarchical assembly of the "artificial atoms" of the structure. Many novel designs have been reported to enable exotic properties of metamaterials. However, experimental realization of these designs is facing a great challenge due to stringent requirements on precise fabrication of subwavelength fine features in three dimensional (3D). In this dissertation, we aim to create powerful and reliable 3D fabrication approaches to bridge the gap between design and realization. Three dimensional fabrication of terahertz (THz) metamaterial and optical metamaterial by additive manufacturing approaches are demonstrated. For fabricating THz metamaterials, the design and testing of a scalable projection micro-stereo-lithography system that offers the 3D fabrication capability is presented. By taking advantage of transformation optics theory, a study in design, fabrication, and characterization of the THz invisibility cloak was performed. The cloak successfully concealed both the geometrical and spectroscopic signatures of an alpha-lactose monohydrate absorber, making it undetectable from 0.3 to 0.6 THz. Following this successful demonstration, we further created the broadband 3D flattened Luneburg lens for THz imaging. The lens is transformed from its original spherical shape and can focus THz plane waves from ultra-wide angles at the focal plane without geometrical aberrations, and vice versa. 2D imaging independent of polarizations is demonstrated. For optical metamaterial, we developed nanoimprint lithography and nanotransfer printing process to realize 3D nano-grating structure in an additive fashion. Based on this method, we successfully designed and created the upright U-shaped spit ring resonators (SRRs) showing artificial magnetism beyond the
Oscillatory cellular patterns in three-dimensional directional solidification
Tourret, D.; Debierre, J.-M.; Song, Y.; Mota, F. L.; Bergeon, N.; Guérin, R.; Trivedi, R.; Billia, B.; Karma, A.
2015-10-01
We present a phase-field study of oscillatory breathing modes observed during the solidification of three-dimensional cellular arrays in microgravity. Directional solidification experiments conducted onboard the International Space Station have allowed us to observe spatially extended homogeneous arrays of cells and dendrites while minimizing the amount of gravity-induced convection in the liquid. In situ observations of transparent alloys have revealed the existence, over a narrow range of control parameters, of oscillations in cellular arrays with a period ranging from about 25 to 125 min. Cellular patterns are spatially disordered, and the oscillations of individual cells are spatiotemporally uncorrelated at long distance. However, in regions displaying short-range spatial ordering, groups of cells can synchronize into oscillatory breathing modes. Quantitative phase-field simulations show that the oscillatory behavior of cells in this regime is linked to a stability limit of the spacing in hexagonal cellular array structures. For relatively high cellular front undercooling (i.e., low growth velocity or high thermal gradient), a gap appears in the otherwise continuous range of stable array spacings. Close to this gap, a sustained oscillatory regime appears with a period that compares quantitatively well with experiment. For control parameters where this gap exists, oscillations typically occur for spacings at the edge of the gap. However, after a change of growth conditions, oscillations can also occur for nearby values of control parameters where this gap just closes and a continuous range of spacings exists. In addition, sustained oscillations at to the opening of this stable gap exhibit a slow periodic modulation of the phase-shift among cells with a slower period of several hours. While long-range coherence of breathing modes can be achieved in simulations for a perfect spatial arrangement of cells as initial condition, global disorder is observed in both
Three-Dimensional Visualization of Interfacial Phenomena Using Confocal Microscopy
Shieh, Ian C.
Surfactants play an integral role in numerous functions ranging from stabilizing the emulsion in a favorite salad dressing to organizing the cellular components that make life possible. We are interested in lung surfactant, which is a mixture of lipids and proteins essential for normal respiration because it modulates the surface tension of the air-liquid interface of the thin fluid lining in the lungs. Through this surface tension modulation, lung surfactant ensures effortless lung expansion and prevents lung collapse during exhalation, thereby effecting proper oxygenation of the bloodstream. The function of lung surfactant, as well as numerous interfacial lipid systems, is not solely dictated by the behavior of materials confined to the two-dimensional interface. Rather, the distributions of materials in the liquid subphase also greatly influence the performance of interfacial films of lung surfactant. Therefore, to better understand the behavior of lung surfactant and other interfacial lipid systems, we require a three-dimensional characterization technique. In this dissertation, we have developed a novel confocal microscopy methodology for investigating the interfacial phenomena of surfactants at the air-liquid interface of a Langmuir trough. Confocal microscopy provides the excellent combination of in situ, fast, three-dimensional visualization of multiple components of the lung surfactant system that other characterization techniques lack. We detail the solutions to the numerous challenges encountered when imaging a dynamic air-liquid interface with a high-resolution technique like confocal microscopy. We then use confocal microscopy to elucidate the distinct mechanisms by which a polyelectrolyte (chitosan) and nonadsorbing polymer (polyethylene glycol) restore the function of lung surfactant under inhibitory conditions mimicking the effects of lung trauma. Beyond this physiological model, we also investigate several one- and two-component interfacial films
Leadership and organizational ethics: the three dimensional African perspectives.
Mathooko, Jude Mutuku
2013-01-01
This paper addresses the past, present and future aspects of African leadership and organizational ethics that have, are and will be key for any organization to sustain its systems and structures. Organizational ethics revolves around written and/or unwritten guidelines, ethical values, principles, rules and standards, that are drawn from the harmonious coexistence with the biosphere and it is how these elements are applied that dictates the style of leadership and the ethical thinking of the leaders. Africa has a wide range of complexities which are compounded by, inter alia, tribal divisiveness, selfish leadership, wealth inequality, and massive unemployment. Africans tend to draw their leadership and ethical practices and reflections from the events in the environment with which they have interacted for many years. However, in order to fully address and understand the African perspective in leadership and organizational ethics, a broad comprehension of the African diverse and complex landscape is needed through unravelling of the three dimensional existence of the people. African ethics, developed over time, unifies organizations and leadership since it is part of life and is practised, sub-consciously or unconsciously, by the people as they transform from one practice to the other, and during intergenerational transitions. Globalization, liberalization, technological changes and advancement, and market changes are rapidly transforming the environment in which organizations operate. In such a situation, an effective and true leader cannot be rigid but should be flexible, with the ability to use different leadership styles whenever the situation calls for it. Only those leaders with a three-dimensional perspective live inspiring lives, live with a cause and adopt organizational ethics and leadership styles that will stand the test of time. Despite Africa being the cradle of humankind, leadership and organizational ethics is still in its infancy and wanting, even
Measurement of three-dimensional deformation using speckle projection method
Zhu, Feipeng; Liu, Wenwen; He, Xiaoyuan
2008-11-01
Optical triangulation is a useful method that has been studied and utilized extensively. In optical triangulation, the directions of projection and the observation are different, so the patterns captured by CCD camera include information of the object surface profile. Based on the speckle projection, a measurement system to get the three-dimensional deformation of object is developed. With artificial random speckle projected to the object surface, two images before and after object deformation are recorded, respectively. In order to get the information of the deformation, digital image correlation method (DICM) is adopted. Furthermore, the calibration is introduced in detail, which is the procedure of great importance, because it determines directly the accuracy of measurement. Due to variable feature of the calibration coefficient along the x direction, this paper presents a new method to be competent for the calibration, that's segmented calibration method. Experiment is performed and good agreement is found with the proposed calibration. Dynamic measurement results based on such system are also presented in this paper.
Three-dimensional ultrasound assessment of endometrial receptivity: a review
Directory of Open Access Journals (Sweden)
Alcázar Juan
2006-11-01
Full Text Available Abstract Three-dimensional ultrasound (3D US is a new imaging modality, which is being introduced into clinical practice. Although this technique will not probably replace two-dimensional ultrasound, it is being increasingly used. It has been reported that 3D US is a very high reproducible technique. The endometrium has been paid special attention when using this technique. The aim of this paper is to address some technical aspects of 3D US and to review critically its current status in evaluating endometrial function with special focus in its role in predicting pregnancy in assisted reproductive techniques. In spontaneous cycles endometrial volume grows during follicular phase remaining constant through the luteal phase. Endometrial vascularization increases during follicular phase peaking 2–3 days before ovulation, decreasing thereafter and increasing again during mid and late luteal phase. Data from studies analysing the role of 3D US for predicting IVF outcome are controversial. An explanation for these controversial findings might be different design of reported studies, specially the timing of ultrasound evaluation.
Micro-assembly of three-dimensional rotary MEMS mirrors
Wang, Lidai; Mills, James K.; Cleghorn, William L.
2009-02-01
We present a novel approach to construct three-dimensional rotary micro-mirrors, which are fundamental components to build 1×N or N×M optical switching systems. A rotary micro-mirror consists of two microparts: a rotary micro-motor and a micro-mirror. Both of the two microparts are fabricated with PolyMUMPs, a surface micromachining process. A sequential robotic microassembly process is developed to join the two microparts together to construct a threedimensional device. In order to achieve high positioning accuracy and a strong mechanical connection, the micro-mirror is joined to the micro-motor using an adhesive mechanical fastener. The mechanical fastener has self-alignment ability and provides a temporary joint between the two microparts. The adhesive bonding can create a strong permanent connection, which does not require extra supporting plates for the micro-mirror. A hybrid manipulation strategy, which includes pick-and-place and pushing-based manipulations, is utilized to manipulation the micro-mirror. The pick-andplace manipulation has the ability to globally position the micro-mirror in six degrees of freedom. The pushing-based manipulation can achieve high positioning accuracy. This microassembly approach has great flexibility and high accuracy; furthermore, it does not require extra supporting plates, which greatly simplifies the assembly process.
Three-Dimensional Tracking of Interfacial Hopping Diffusion
Wang, Dapeng; Wu, Haichao; Schwartz, Daniel K.
2017-12-01
Theoretical predictions have suggested that molecular motion at interfaces—which influences processes including heterogeneous catalysis, (bio)chemical sensing, lubrication and adhesion, and nanomaterial self-assembly—may be dominated by hypothetical "hops" through the adjacent liquid phase, where a diffusing molecule readsorbs after a given hop according to a probabilistic "sticking coefficient." Here, we use three-dimensional (3D) single-molecule tracking to explicitly visualize this process for human serum albumin at solid-liquid interfaces that exert varying electrostatic interactions on the biomacromolecule. Following desorption from the interface, a molecule experiences multiple unproductive surface encounters before readsorption. An average of approximately seven surface collisions is required for the repulsive surfaces, decreasing to approximately two and a half for surfaces that are more attractive. The hops themselves are also influenced by long-range interactions, with increased electrostatic repulsion causing hops of longer duration and distance. These findings explicitly demonstrate that interfacial diffusion is dominated by biased 3D Brownian motion involving bulk-surface coupling and that it can be controlled by influencing short- and long-range adsorbate-surface interactions.
Three-dimensional inkjet biofabrication based on designed images
Energy Technology Data Exchange (ETDEWEB)
Arai, Kenichi; Iwanaga, Shintaroh; Toda, Hideki; Genci, Capi; Nakamura, Makoto [Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan); Nishiyama, Yuichi, E-mail: maknaka@eng.u-toyama.ac.jp [Bioprinting Project of Kanagawa Academy of Science and Technology, Kawasaki (Japan)
2011-09-15
Tissue engineering has been developed with the ultimate aim of manufacturing human organs, but success has been limited to only thin tissues and tissues with no significant structures. In order to construct more complicated tissues, we have developed a three-dimensional (3D) fabrication technology in which 3D structures are directly built up by layer-by-layer printing with living cells and several tissue components. We developed a custom-made inkjet printer specially designed for this purpose. Recently, this printer was improved, and the on-demand printing mode was developed and installed to fabricate further complicated structures. As a result of this version, 3D layer-by-layer printing based on complicated image data has become possible, and several 2D and 3D structures with more complexity than before were successfully fabricated. The effectiveness of the on-demand printing mode in the fabrication of complicated 3D tissue structures was confirmed. As complicated 3D structures are essential for biofunctional tissues, inkjet 3D biofabrication has great potential for engineering complicated bio-functional tissues.
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)
Self-assembled three dimensional network designs for soft electronics
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.
A Three-Dimensional Model of the Yeast Genome
Noble, William; Duan, Zhi-Jun; Andronescu, Mirela; Schutz, Kevin; McIlwain, Sean; Kim, Yoo Jung; Lee, Choli; Shendure, Jay; Fields, Stanley; Blau, C. Anthony
Layered on top of information conveyed by DNA sequence and chromatin are higher order structures that encompass portions of chromosomes, entire chromosomes, and even whole genomes. Interphase chromosomes are not positioned randomly within the nucleus, but instead adopt preferred conformations. Disparate DNA elements co-localize into functionally defined aggregates or factories for transcription and DNA replication. In budding yeast, Drosophila and many other eukaryotes, chromosomes adopt a Rabl configuration, with arms extending from centromeres adjacent to the spindle pole body to telomeres that abut the nuclear envelope. Nonetheless, the topologies and spatial relationships of chromosomes remain poorly understood. Here we developed a method to globally capture intra- and inter-chromosomal interactions, and applied it to generate a map at kilobase resolution of the haploid genome of Saccharomyces cerevisiae. The map recapitulates known features of genome organization, thereby validating the method, and identifies new features. Extensive regional and higher order folding of individual chromosomes is observed. Chromosome XII exhibits a striking conformation that implicates the nucleolus as a formidable barrier to interaction between DNA sequences at either end. Inter-chromosomal contacts are anchored by centromeres and include interactions among transfer RNA genes, among origins of early DNA replication and among sites where chromosomal breakpoints occur. Finally, we constructed a three-dimensional model of the yeast genome. Our findings provide a glimpse of the interface between the form and function of a eukaryotic genome.
Dynamic properties of three-dimensional piezoelectric Kagome grids
Wu, Zhi-Jing; Li, Feng-Ming
2015-07-01
Piezoelectric Kagome grids can be considered as a kind of functional material because they have vibration isolation performance and can transform mechanical energy to electric energy. In this study, the dynamic properties of three-dimensional (3D) piezoelectric Kagome grids without and with material defects are studied based on the frequency-domain responses. The spectral element method (SEM) is adopted to solve a 3D piezoelectric beam which contains bending components in two planes, tensional components, and torsional components. The dynamic stiffness matrix of a spectral piezoelectric beam is derived. Highly accurate solutions in the frequency-domain are obtained by solving the equation of motion of the whole structure. Compared with the results from the FEM and those in the existing literature, it can be seen that the SEM can be effectively used to study the 3D piezoelectric Kagome grids. The band-gap properties of Kagome grid and defect state properties of Kagome grid with material defects are analyzed. The effect of the piezoelectric parameter on the band-gap property is investigated further.
Simplified two and three dimensional HTTR benchmark problems
Energy Technology Data Exchange (ETDEWEB)
Zhang Zhan [Nuclear and Radiological Engineering and Medical Physics Programs, George W. Woodruff School, Georgia Institute of Technology, 770 State St., Atlanta, GA 30332 (United States); Rahnema, Farzad, E-mail: Farzad@gatech.edu [Nuclear and Radiological Engineering and Medical Physics Programs, George W. Woodruff School, Georgia Institute of Technology, 770 State St., Atlanta, GA 30332 (United States); Zhang Dingkang; Pounders, Justin M. [Nuclear and Radiological Engineering and Medical Physics Programs, George W. Woodruff School, Georgia Institute of Technology, 770 State St., Atlanta, GA 30332 (United States); Ougouag, Abderrafi M. [Idaho National Laboratory, Ms-3860, PO Box 1625, Idaho Falls, ID 83415-3860 (United States)
2011-05-15
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.
Study of Three-Dimensional Image Brightness Loss in Stereoscopy
Directory of Open Access Journals (Sweden)
Hsing-Cheng Yu
2015-10-01
Full Text Available When viewing three-dimensional (3D images, whether in cinemas or on stereoscopic televisions, viewers experience the same problem of image brightness loss. This study aims to investigate image brightness loss in 3D displays, with the primary aim being to quantify the image brightness degradation in the 3D mode. A further aim is to determine the image brightness relationship to the corresponding two-dimensional (2D images in order to adjust the 3D-image brightness values. In addition, the photographic principle is used in this study to measure metering values by capturing 2D and 3D images on television screens. By analyzing these images with statistical product and service solutions (SPSS software, the image brightness values can be estimated using the statistical regression model, which can also indicate the impact of various environmental factors or hardware on the image brightness. In analysis of the experimental results, comparison of the image brightness between 2D and 3D images indicates 60.8% degradation in the 3D image brightness amplitude. The experimental values, from 52.4% to 69.2%, are within the 95% confidence interval
Quantitative evaluation of performance of three-dimensional printed lenses
Gawedzinski, John; Pawlowski, Michal E.; Tkaczyk, Tomasz S.
2017-08-01
We present an analysis of the shape, surface quality, and imaging capabilities of custom three-dimensional (3-D) printed lenses. 3-D printing technology enables lens prototypes to be fabricated without restrictions on surface geometry. Thus, spherical, aspherical, and rotationally nonsymmetric lenses can be manufactured in an integrated production process. This technique serves as a noteworthy alternative to multistage, labor-intensive, abrasive processes, such as grinding, polishing, and diamond turning. Here, we evaluate the quality of lenses fabricated by Luxexcel using patented Printoptical©; technology that is based on an inkjet printing technique by comparing them to lenses made with traditional glass processing technologies (grinding, polishing, etc.). The surface geometry and roughness of the lenses were evaluated using white-light and Fizeau interferometers. We have compared peak-to-valley wavefront deviation, root mean square (RMS) wavefront error, radii of curvature, and the arithmetic roughness average (Ra) profile of plastic and glass lenses. In addition, the imaging performance of selected pairs of lenses was tested using 1951 USAF resolution target. The results indicate performance of 3-D printed optics that could be manufactured with surface roughness comparable to that of injection molded lenses (Ra<20 nm). The RMS wavefront error of 3-D printed prototypes was at a minimum 18.8 times larger than equivalent glass prototypes for a lens with a 12.7 mm clear aperture, but, when measured within 63% of its clear aperture, the 3-D printed components' RMS wavefront error was comparable to glass lenses.
Effects of a three-dimensional bimetric maxillary distalizing arch.
Uçem, T T; Yüksel, S; Okay, C; Gülşen, A
2000-06-01
This study aimed to investigate the dental effects of a three-dimensional (3D) bimetric maxillary distalizing arch. The Wilson rapid molar distalization appliance for Class II molar correction was used in 14 patients (10 girls and four boys with a mean age of 12.18 years). The open coil springs were activated with bent Omega stops and Class II intermaxillary elastics. The mandibular anchorage was gained by a 0.016 x 0.016 utility arch with a 3D lingual arch or a lip bumper with a standard lingual arch. The lateral cephalograms taken before and after treatment formed the material of the research. A Wilcoxon test was used to statistically evaluate the treatment effects. The results showed that the distal tipping of the maxillary first and second molars, and first and second premolars and canines were statistically significant. Significant distal movement occurred in all posterior and canine teeth. The maxillary first molar distalization was found to be 3.5 mm. The maxillary incisor showed significant proclination and protrusion. The decrease in overbite was found to be statistically significant. The mandibular plane angle significantly increased by a mean of 0.5 mm. In addition, significant soft tissue changes were observed.
Three-dimensional dynamics of protostellar evolution. [Nonlinear problems, kinetics
Energy Technology Data Exchange (ETDEWEB)
Cook, T.L.
1977-06-01
A three-dimensional finite difference numerical methodology was developed for self-gravitating, rotating gaseous systems. The fully nonlinear equations for time-varying fluid dynamics are solved by high speed computer in a cylindrical coordinate system rotating with an instantaneous angular velocity, selected such that the net angular momentum relative to the rotating frame is zero. The time-dependent adiabatic collapse of gravitationally bound, rotating, protostellar clouds is studied for specified uniform and nonuniform initial conditions. Uniform clouds can form axisymmetric, rotating toroidal configurations. If the thermal pressure is high, nonuniform clouds can also collapse to axisymmetric toroids. For low thermal pressures, however, the collapsing cloud is unstable to initial perturbations. The fragmentation of protostellar clouds is investigated by studying the response of rotating, self-gravitating, equilibrium toroids to non-axisymmetric perturbations. The detailed evolution of the fragmenting toroid depends upon a non-dimensional function of the initial entropy, the total mass in the toroid, the angular velocity of rotation, and the number of perturbation wavelengths around the circumference of the toroid. For low and intermediate entropies, the configuration develops into co-rotating components with spiral streamers. In the spiral regions retrograde vortices are observed in some examples. For high levels of entropy, barred spirals can exist as intermediate states of the fragmentation.
Design of a three-dimensional multitarget activity landscape.
de la Vega de León, Antonio; Bajorath, Jürgen
2012-11-26
The design of activity landscape representations is challenging when compounds are active against multiple targets. Going beyond three or four targets, the complexity of underlying activity spaces is difficult to capture in conventional activity landscape views. Previous attempts to generate multitarget activity landscapes have predominantly utilized extensions of molecular network representations or plots of activity versus chemical similarity for pairs of active compounds. Herein, we introduce a three-dimensional multitarget activity landscape design that is based upon principles of radial coordinate visualization. Circular representations of multitarget activity and chemical reference space are combined to generate a spherical view into which compound sets are projected for interactive analysis. Interpretation of landscape content is facilitated by following three canonical views of activity, chemical, and combined activity/chemical space, respectively. These views focus on different planes of the underlying coordinate system. From the activity and combined views, compounds with well-defined target selectivity and structure-activity profile relationships can be extracted. In the activity landscape, such compounds display characteristic spatial arrangements and target activity patterns.
Three-dimensional electrical impedance tomography: a topology optimization approach.
Mello, Luís Augusto Motta; de Lima, Cícero Ribeiro; Amato, Marcelo Britto Passos; Lima, Raul Gonzalez; Silva, Emílio Carlos Nelli
2008-02-01
Electrical impedance tomography is a technique to estimate the impedance distribution within a domain, based on measurements on its boundary. In other words, given the mathematical model of the domain, its geometry and boundary conditions, a nonlinear inverse problem of estimating the electric impedance distribution can be solved. Several impedance estimation algorithms have been proposed to solve this problem. In this paper, we present a three-dimensional algorithm, based on the topology optimization method, as an alternative. A sequence of linear programming problems, allowing for constraints, is solved utilizing this method. In each iteration, the finite element method provides the electric potential field within the model of the domain. An electrode model is also proposed (thus, increasing the accuracy of the finite element results). The algorithm is tested using numerically simulated data and also experimental data, and absolute resistivity values are obtained. These results, corresponding to phantoms with two different conductive materials, exhibit relatively well-defined boundaries between them, and show that this is a practical and potentially useful technique to be applied to monitor lung aeration, including the possibility of imaging a pneumothorax.
Three dimensional massively-parallel simulation of falling liquid films
Shin, Seungwon; Adebayo, Idris; Kahouadji, Lyes; Chergui, Jalel; Juric, Damir; Matar, Omar K.
2017-11-01
We present results on the numerical study of falling liquid films using direct numerical simulations. Falling films due to their rich dynamics have been a subject of many interesting studies over the past decades. However, the majority of the research in the literature has focused only on the two-dimensional case due to the complexity of three-dimensional studies. In this work, we solve the full Navier-Stokes equations using a massively-parallelised numerical code ``Blue''. The code utilises a domain-decomposition strategy for parallelization with MPI, and an hybrid front-tracking/level set method is designed to handle the deforming interface. Parallel GMRES and Multigrid iterative solvers are then employed to appropriately handle the linear system arising from the implicit solution for the fluid velocities and pressure in the presence of strong density and viscosity discontinuities across the fluid phases. Our result show many interesting dynamics, which cannot be observed in the two-dimensional studies. Petroleum Technology Development Fund, EPSRC, UK, MEMPHIS program Grant (EP/K003976/1), RAEng Research Chair (OKM).
Three-dimensional Monte Carlo calculation of some nuclear parameters
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.
Three-dimensional structure determination from a single view.
Raines, Kevin S; Salha, Sara; Sandberg, Richard L; Jiang, Huaidong; Rodríguez, Jose A; Fahimian, Benjamin P; Kapteyn, Henry C; Du, Jincheng; Miao, Jianwei
2010-01-14
The ability to determine the structure of matter in three dimensions has profoundly advanced our understanding of nature. Traditionally, the most widely used schemes for three-dimensional (3D) structure determination of an object are implemented by acquiring multiple measurements over various sample orientations, as in the case of crystallography and tomography, or by scanning a series of thin sections through the sample, as in confocal microscopy. Here we present a 3D imaging modality, termed ankylography (derived from the Greek words ankylos meaning 'curved' and graphein meaning 'writing'), which under certain circumstances enables complete 3D structure determination from a single exposure using a monochromatic incident beam. We demonstrate that when the diffraction pattern of a finite object is sampled at a sufficiently fine scale on the Ewald sphere, the 3D structure of the object is in principle determined by the 2D spherical pattern. We confirm the theoretical analysis by performing 3D numerical reconstructions of a sodium silicate glass structure at 2 A resolution, and a single poliovirus at 2-3 nm resolution, from 2D spherical diffraction patterns alone. Using diffraction data from a soft X-ray laser, we also provide a preliminary demonstration that ankylography is experimentally feasible by obtaining a 3D image of a test object from a single 2D diffraction pattern. With further development, this approach of obtaining complete 3D structure information from a single view could find broad applications in the physical and life sciences.
Three-dimensional analysis of a postbuckled embedded delamination
Whitcomb, John D.
1989-01-01
Delamination growth caused by local buckling of a delaminated group of plies was investigated. Delamination growth was assumed to be governed by the strain energy release rates, G(1), G(2) and G(3). The strain energy release rates were calculated using a geometrically nonlinear three-dimensional finite element analysis. The program is described and several checks of the analysis are discussed. Based on a limited parametric study, the following conclusions were reached: (1) the problem is definitely mixed mode (in some cases G(1) is larger than G(2), for other cases the opposite is true); (2) in general, there is a large gradient in the strain energy release rates along the delamination front; (3) the locations of maximum G(1) and G(2) depend on the delamination shape and the applied strain; (4) the mode 3 component was negligible for all cases considered; and (5) the analysis predicted that parts of the delamination would overlap. The results presented did not impose contact constraints to prevent overlapping. Further work is needed to determine the effects of allowing the overlapping.
Three-Dimensional scanning transmission electron microscopy of biological specimens
De Jonge, Niels
2010-01-18
A three-dimensional (3D) reconstruction of the cytoskeleton and a clathrin-coated pit in mammalian cells has been achieved from a focal-series of images recorded in an aberration-corrected scanning transmission electron microscope (STEM). The specimen was a metallic replica of the biological structure comprising Pt nanoparticles 2-3 nm in diameter, with a high stability under electron beam radiation. The 3D dataset was processed by an automated deconvolution procedure. The lateral resolution was 1.1 nm, set by pixel size. Particles differing by only 10 nm in vertical position were identified as separate objects with greater than 20% dip in contrast between them. We refer to this value as the axial resolution of the deconvolution or reconstruction, the ability to recognize two objects, which were unresolved in the original dataset. The resolution of the reconstruction is comparable to that achieved by tilt-series transmission electron microscopy. However, the focal-series method does not require mechanical tilting and is therefore much faster. 3D STEM images were also recorded of the Golgi ribbon in conventional thin sections containing 3T3 cells with a comparable axial resolution in the deconvolved dataset. © 2010 Microscopy Society of America.
Three-dimensional photoacoustic endoscopic imaging of the rabbit esophagus.
Directory of Open Access Journals (Sweden)
Joon Mo Yang
Full Text Available We report photoacoustic and ultrasonic endoscopic images of two intact rabbit esophagi. To investigate the esophageal lumen structure and microvasculature, we performed in vivo and ex vivo imaging studies using a 3.8-mm diameter photoacoustic endoscope and correlated the images with histology. Several interesting anatomic structures were newly found in both the in vivo and ex vivo images, which demonstrates the potential clinical utility of this endoscopic imaging modality. In the ex vivo imaging experiment, we acquired high-resolution motion-artifact-free three-dimensional photoacoustic images of the vasculatures distributed in the walls of the esophagi and extending to the neighboring mediastinal regions. Blood vessels with apparent diameters as small as 190 μm were resolved. Moreover, by taking advantage of the dual-mode high-resolution photoacoustic and ultrasound endoscopy, we could better identify and characterize the anatomic structures of the esophageal lumen, such as the mucosal and submucosal layers in the esophageal wall, and an esophageal branch of the thoracic aorta. In this paper, we present the first photoacoustic images showing the vasculature of a vertebrate esophagus and discuss the potential clinical applications and future development of photoacoustic endoscopy.
Magnetic reconstruction of three-dimensional tissues from multicellular spheroids.
Lin, Ruei-Zeng; Chu, Wen-Chen; Chiang, Chao-Chien; Lai, Chih-Huang; Chang, Hwan-You
2008-09-01
Multicellular spheroids are useful building blocks for tissue reconstruction. This study reports a simple technique called magnetic organoid patterning for assembly of spheroids into a complex tissue-mimicking construct. Spheroids were labeled magnetically using co-incubation of RGD peptide-conjugated magnetic microparticles and single cells in suspension culture. The labeled spheroids can be manipulated individually or in parallel with a magnet without producing apparent effects on cell growth and migration. Spheroid patterns such as rings, lines, and arrays can be efficiently generated using this method. The patterned spheroid can be immobilized in functional hydrogels, in which fusion of neighboring spheroids and tissue-specific features were observed. Spheroid patterns temporarily encapsulated in a thermal-responsive hydrogel can be stacked layer by layer to generate thick three-dimensional (3D) tissues. These results indicate that magnetic organoid patterning is useful for construction of complex 3D tissue and will find applications in cell-to-cell interaction research, drug screening, and regenerative medicine.
Binocular Disparity Limit in Three-dimensional Display Systems
Qin, Damin; Takamatsu, Mamoru; Nakashima, Yoshio
In three-dimensional display systems, binocular disparities must be limited within a certain fusional area, called as “Panum's fusional area". Otherwise, too larger disparity could cause double view or serious eye fatigue. However, the measurements about Panum's fusional area in the previous studies focused only on the horizontal and vertical meridian of retina. For fully measuring the Panum's fusional area in more directions, we took the measurements of the limits of Panum's fusional area, in sixteen different directions from 0 degree to 360 degrees by a step of 22.5 degrees in the fovea. It was found that the horizontal disparity limit of binocular fusional area is about 32-38.4 min of arc and the vertical limit is about 19.2-24 min of arc. The disparity limits of binocular fusional area are approximately symmetrical about horizontal meridian. However, the disparity limits are not symmetrical about vertical meridian; the nasalward disparity limits are obviously larger than temporalward disparity limits. Moreover, in the nasal side of retina, the disparity limits decrease in a monotonic fashion, and in the temporal side, however, the disparity limits have no obvious difference.
Three-dimensional ocular kinematics underlying binocular single vision.
Hess, Bernhard J M; Misslisch, H
2016-12-01
We have analyzed the binocular coordination of the eyes during far-to-near refixation saccades based on the evaluation of distance ratios and angular directions of the projected target images relative to the eyes' rotation centers. By defining the geometric point of binocular single vision, called Helmholtz point, we found that disparities during fixations of targets at near distances were limited in the subject's three-dimensional visual field to the vertical and forward directions. These disparities collapsed to simple vertical disparities in the projective binocular image plane. Subjects were able to perfectly fuse the vertically disparate target images with respect to the projected Helmholtz point of single binocular vision, independent of the particular location relative to the horizontal plane of regard. Target image fusion was achieved by binocular torsion combined with corrective modulations of the differential half-vergence angles of the eyes in the horizontal plane. Our findings support the notion that oculomotor control combines vergence in the horizontal plane of regard with active torsion in the frontal plane to achieve fusion of the dichoptic binocular target images. Copyright © 2016 the American Physiological Society.
Aurora-associated three-dimensional current system
Energy Technology Data Exchange (ETDEWEB)
Zhang Fengying.
1993-05-01
Ground based measurements from the CANOPUS All-sky Imager (ASI), the Bistatic Auroral Radar System (BARS), and the Magnetometer and Riometer Array (MARIA) were combined to infer a three-dimensional current system of finite width and length in the auroral zone using a new method of quantitative analysis. In this new method, the auroral emission rates I(427.8 nm) and I(630.0 nm) were used to calculate the Pedersen and Hall height-integrated conductivities in the auroral arc region. Electric fields were measured from the BARS. Ohm's law and the current continuity equation were used to derive the current system. The resulting current system consisted of 400 ionospheric (horizontal) current vectors and 400 field-aligned current vectors in the field of view. The three cases selected were near midnight. The current system found is a combination of two types of Bostroem current systems within a small region. The magnetic perturbations on the ground resulting from the current system were calculated and compared with the magnetic observations from MARIA. The good agreement shows that the inferred current system is reasonable, and the major current source producing the magnetic perturbations on the ground is the current system in the auroral region overhead. 71 refs., 42 figs., 2 tabs.
Three-dimensional fingerprint recognition by using convolution neural network
Tian, Qianyu; Gao, Nan; Zhang, Zonghua
2018-01-01
With the development of science and technology and the improvement of social information, fingerprint recognition technology has become a hot research direction and been widely applied in many actual fields because of its feasibility and reliability. The traditional two-dimensional (2D) fingerprint recognition method relies on matching feature points. This method is not only time-consuming, but also lost three-dimensional (3D) information of fingerprint, with the fingerprint rotation, scaling, damage and other issues, a serious decline in robustness. To solve these problems, 3D fingerprint has been used to recognize human being. Because it is a new research field, there are still lots of challenging problems in 3D fingerprint recognition. This paper presents a new 3D fingerprint recognition method by using a convolution neural network (CNN). By combining 2D fingerprint and fingerprint depth map into CNN, and then through another CNN feature fusion, the characteristics of the fusion complete 3D fingerprint recognition after classification. This method not only can preserve 3D information of fingerprints, but also solves the problem of CNN input. Moreover, the recognition process is simpler than traditional feature point matching algorithm. 3D fingerprint recognition rate by using CNN is compared with other fingerprint recognition algorithms. The experimental results show that the proposed 3D fingerprint recognition method has good recognition rate and robustness.
Three-Dimensional Electromagnetic High Frequency Axisymmetric Cavity Scars.
Energy Technology Data Exchange (ETDEWEB)
Warne, Larry Kevin; Jorgenson, Roy Eberhardt
2014-10-01
This report examines the localization of high frequency electromagnetic fi elds in three-dimensional axisymmetric cavities along periodic paths between opposing sides of the cavity. The cases where these orbits lead to unstable localized modes are known as scars. This report treats both the case where the opposing sides, or mirrors, are convex, where there are no interior foci, and the case where they are concave, leading to interior foci. The scalar problem is treated fi rst but the approximations required to treat the vector fi eld components are also examined. Particular att ention is focused on the normalization through the electromagnetic energy theorem. Both projections of the fi eld along the scarred orbit as well as point statistics are examined. Statistical comparisons are m ade with a numerical calculation of the scars run with an axisymmetric simulation. This axisymmetric cas eformstheoppositeextreme(wherethetwomirror radii at each end of the ray orbit are equal) from the two -dimensional solution examined previously (where one mirror radius is vastly di ff erent from the other). The enhancement of the fi eldontheorbitaxiscanbe larger here than in the two-dimensional case. Intentionally Left Blank
Instrumented cardiac microphysiological devices via multimaterial three-dimensional printing
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.
Two and three dimensional magnetotelluric inversion. Final report
Energy Technology Data Exchange (ETDEWEB)
Booker, J.
1993-05-01
Electrical conductivity depends on properties such as the presence of ionic fluids in interconnected pores that are difficult to sense with other remote sensing techniques. Thus improved imaging of underground electrical structure has wide practical importance in exploring for groundwater, mineral and geothermal resources, and in assessing the diffusion of fluids in oil fields and waste sites. Because the electromagnetic inverse problem is fundamentally multi-dimensional, most imaging algorithms saturate available computer power long before they can deal with the complete data set. We have developed an algorithm to directly invert large multi-dimensional data sets that is orders of magnitude faster than competing methods. We have proven that a two-dimensional (2D) version of the algorithm is highly effective for real data and have made substantial progress towards a three-dimensional (3D) version. We are proposing to cure identified shortcomings and substantially expand the utility of the existing 2D program, overcome identified difficulties with extending our method to three-dimensions (3D) and embark on an investigation of related EM imaging techniques which may have the potential for even further increasing resolution.
Three-dimensional cardiac computational modelling: methods, features and applications.
Lopez-Perez, Alejandro; Sebastian, Rafael; Ferrero, Jose M
2015-04-17
The combination of computational models and biophysical simulations can help to interpret an array of experimental data and contribute to the understanding, diagnosis and treatment of complex diseases such as cardiac arrhythmias. For this reason, three-dimensional (3D) cardiac computational modelling is currently a rising field of research. The advance of medical imaging technology over the last decades has allowed the evolution from generic to patient-specific 3D cardiac models that faithfully represent the anatomy and different cardiac features of a given alive subject. Here we analyse sixty representative 3D cardiac computational models developed and published during the last fifty years, describing their information sources, features, development methods and online availability. This paper also reviews the necessary components to build a 3D computational model of the heart aimed at biophysical simulation, paying especial attention to cardiac electrophysiology (EP), and the existing approaches to incorporate those components. We assess the challenges associated to the different steps of the building process, from the processing of raw clinical or biological data to the final application, including image segmentation, inclusion of substructures and meshing among others. We briefly outline the personalisation approaches that are currently available in 3D cardiac computational modelling. Finally, we present examples of several specific applications, mainly related to cardiac EP simulation and model-based image analysis, showing the potential usefulness of 3D cardiac computational modelling into clinical environments as a tool to aid in the prevention, diagnosis and treatment of cardiac diseases.
Three-dimensional cinematography with control object of unknown shape.
Dapena, J; Harman, E A; Miller, J A
1982-01-01
A technique for reconstruction of three-dimensional (3D) motion which involves a simple filming procedure but allows the deduction of coordinates in large object volumes was developed. Internal camera parameters are calculated from measurements of the film images of two calibrated crosses while external camera parameters are calculated from the film images of points in a control object of unknown shape but at least one known length. The control object, which includes the volume in which the activity is to take place, is formed by a series of poles placed at unknown locations, each carrying two targets. From the internal and external camera parameters, and from locations of the images of point in the films of the two cameras, 3D coordinates of the point can be calculated. Root mean square errors of the three coordinates of points in a large object volume (5m x 5m x 1.5m) were 15 mm, 13 mm, 13 mm and 6 mm, and relative errors in lengths averaged 0.5%, 0.7% and 0.5%, respectively.
Resonance fluorescence microscopy via three-dimensional atom localization
Panchadhyayee, Pradipta; Dutta, Bibhas Kumar; Das, Nityananda; Mahapatra, Prasanta Kumar
2018-02-01
A scheme is proposed to realize three-dimensional (3D) atom localization in a driven two-level atomic system via resonance fluorescence. The field arrangement for the atom localization involves the application of three mutually orthogonal standing-wave fields and an additional traveling-wave coupling field. We have shown the efficacy of such field arrangement in tuning the spatially modulated resonance in all directions. Under different parametric conditions, the 3D localization patterns originate with various shapes such as sphere, sheets, disk, bowling pin, snake flute, flower vase. High-precision localization is achieved when the radiation field detuning equals twice the combined Rabi frequencies of the standing-wave fields. Application of a traveling-wave field of suitable amplitude at optimum radiation field detuning under symmetric standing-wave configuration leads to 100% detection probability even in sub-wavelength domain. Asymmetric field configuration is also taken into consideration to exhibit atom localization with appreciable precision compared to that of the symmetric case. The momentum distribution of the localized atoms is found to follow the Heisenberg uncertainty principle under the validity of Raman-Nath approximation. The proposed field configuration is suitable for application in the study of atom localization in an optical lattice arrangement.
Three-dimensional diastolic blood flow in the left ventricle.
Khalafvand, Seyed Saeid; Ng, Eddie Yin-Kwee; Zhong, Liang; Hung, Tin-Kan
2017-01-04
Three-dimensional blood flow in a human left ventricle is studied via a computational analysis with magnetic resonance imaging of the cardiac motion. Formation, growth and decay of vortices during the myocardial dilation are analyzed with flow patterns on various diametric planes. They are dominated by momentum transfer during flow acceleration and deceleration through the mitral orifice. The posterior and anterior vortices form an asymmetric annular vortex at the mitral orifice, providing a smooth transition for the rapid inflow to the ventricle. The development of core vortex accommodates momentum for deceleration and for acceleration at end diastolic atrial contraction. The rate of energy dissipation and that of work done by viscous stresses are small; they are approximately balanced with each other. The kinetic energy flux and the rate of work done by pressure delivered to blood from ventricular dilation is well balanced by the total energy influx at the mitral orifice and the rate change of kinetic energy in the ventricle. Published by Elsevier Ltd.
Self-assembled three dimensional network designs for soft electronics
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.
2017-01-01
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. PMID:28635956
Longitudinal Bioluminescent Quantification of Three Dimensional Cell Growth.
Wendt, Michael K; Schiemann, William P
2013-12-05
The use of three-dimensional (3D) cell culture systems is widely accepted as representing a more physiologically relevant means to propagate mammary epithelial and breast cancer cells. However, 3D cultures systems are plagued by several experimental and technical limitations as compared to their traditional 2D counterparts. For instance, quantifying the growth of mammary epithelial or breast cancer organoids longitudinally is particularly troublesome using standard [3H]thymidine or MTT assay systems, or using computer-assisted area calculations. Likewise, the nature of the multicellular aggregates and organoids formed by breast cancer cells under 3D conditions precludes efficient recovery of the cells from 3D matrices, an event that is time consuming and leads to spurious results. The assay described here utilizes stable expression of firefly luciferase as means to quantify the longitudinal outgrowth of cells propagated within a 3D matrices. The major advantages of this technique include its high-throughput nature and ability to longitudinally track single wells over a defined period of time, thereby decreasing the costs associated with assay performance. Finally, this technique can be readily combined with drug treatments and/or genetic manipulations to assay their effects on the growth of 3D organoids.
Three-dimensional frictional plastic strain partitioning during oblique rifting
Duclaux, Guillaume; Huismans, Ritske S.; May, Dave
2017-04-01
Throughout the Wilson cycle the obliquity between lithospheric plate motion direction and nascent or existing plate boundaries prompts the development of intricate three-dimensional tectonic systems. Where oblique divergence dominates, as in the vast majority of continental rift and incipient oceanic domains, deformation is typically transtensional and large stretching in the brittle upper crust is primarily achieved by the accumulation of displacement on fault networks of various complexity. In continental rift depressions such faults are initially distributed over tens to hundreds of kilometer-wide regions, which can ultimately stretch and evolve into passive margins. Here, we use high-resolution 3D thermo-mechanical finite element models to investigate the relative timing and distribution of localised frictional plastic deformation in the upper crust during oblique rift development in a simplified layered lithosphere. We vary the orientation of a wide oblique heterogeneous weak zone (representing a pre-existing geologic feature like a past orogenic domain), and test the sensitivity of the shear zones orientation to a range of noise distribution. These models allow us to assess the importance of material heterogeneities for controlling the spatio-temporal shear zones distribution in the upper crust during oblique rifting, and to discuss the underlying controls governing oblique continental breakup.
Self-assembled three dimensional network designs for soft electronics.
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.
Thermal convection in three-dimensional fractured porous media
Mezon, C.; Mourzenko, V. V.; Thovert, J.-F.; Antoine, R.; Fontaine, F.; Finizola, A.; Adler, P. M.
2018-01-01
Thermal convection is numerically computed in three-dimensional (3D) fluid saturated isotropically fractured porous media. Fractures are randomly inserted as two-dimensional (2D) convex polygons. Flow is governed by Darcy's 2D and 3D laws in the fractures and in the porous medium, respectively; exchanges take place between these two structures. Results for unfractured porous media are in agreement with known theoretical predictions. The influence of parameters such as the fracture aperture (or fracture transmissivity) and the fracture density on the heat released by the whole system is studied for Rayleigh numbers up to 150 in cubic boxes with closed-top conditions. Then, fractured media are compared to homogeneous porous media with the same macroscopic properties. Three major results could be derived from this study. The behavior of the system, in terms of heat release, is determined as a function of fracture density and fracture transmissivity. First, the increase in the output flux with fracture density is linear over the range of fracture density tested. Second, the increase in output flux as a function of fracture transmissivity shows the importance of percolation. Third, results show that the effective approach is not always valid, and that the mismatch between the full calculations and the effective medium approach depends on the fracture density in a crucial way.
Three-dimensional dendrite-tip morphology at low undercooling
Energy Technology Data Exchange (ETDEWEB)
Karma, Alain [Physics Department and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115 (United States); Lee, Youngyih H. [Physics Department and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115 (United States); Plapp, Mathis [Physics Department and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115 (United States)
2000-04-01
We investigate the three-dimensional morphology of the dendrite tip using the phase-field method. We find that, for low undercoolings, this morphology is ostensibly independent of anisotropy strength except for a localized shape distortion near the tip that only affects the value of the tip radius {rho} [which is crudely approximated by {rho}{approx_equal}(1-{alpha}){rho}{sub Iv} where {rho}{sub Iv} is the Ivantsov tip radius of an isothermal paraboloid with the same tip velocity and {alpha} is the stiffness anisotropy]. The universal tip shape, which excludes this distortion, is well fitted by the form z=-r{sup 2}/2+A{sub 4}r{sup 4} cos 4{phi} where |z| is the distance from the tip and all lengths are scaled by {rho}{sub Iv}. This fit yields A{sub 4} in the range 0.004-0.005 in good quantitative agreement with the existing tip morphology measurements in succinonitrile [LaCombe et al., Phys. Rev. E 52, 2778 (1995)], which are reanalyzed here and found to be consistent with a single cos 4{phi} mode nonaxisymmetric deviation from a paraboloid. Moreover, the fin shape away from the tip is well fitted by the power law z=-a|x|{sup 5/3} with a{approx_equal}0.68. Finally, the characterization of the operating state of the dendrite tip is revisited in the light of these results. (c) 2000 The American Physical Society.
Does videoendoscopy provide three-dimensional vision in closed rhinoplasty?
Ozturk, Guncel; Aysal, Bilge Kagan
2017-08-16
Rhinoplasty is a common procedure in cosmetic surgery all over the world. Patients desire enhancement of their facial beauty by the correction of preexisting nasal deformities. Precisely performed operations lead to better results, and enhancing technical accuracy accordingly results in more successful outcomes. Endoscopy helps us visualize the closed parts of the body with the aid of an illuminated optical device. The objective behind the present case series was to bring the advantages of open and closed rhinoplasty together by using endoscopic vision systems. A total of 312 patients with unoperated nasal deformities from private practice were operated, and videoendoscopic closed rhinoplasty was performed on each patient. Postoperative patient satisfaction was assessed using the Rhinoplasty Outcome Score; the level of satisfaction was found to be excellent. In the present case series, it was hypothesized that trocar mobility under the skin flap allows virtual binocular vision that eventually leads to stereoptic depth perception. This allows virtual three-dimensional (3D) vision on the screen of the endoscope with a regular trocar. The mobility of the tip in the transverse axis created a virtual 3D appearance. Our experiences with videoendoscopic closed rhinoplasty are shared in this report. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Magnetic plasmon induced transparency in three-dimensional metamolecules
Wu, Pin Chieh; Chen, Wei Ting; Yang, Kuang-Yu; Hsiao, Chih Ting; Sun, Greg; Liu, Ai Qun; Zheludev, Nikolay I.; Tsai, Din Ping
2012-11-01
In a laser-driven atomic quantum system, a continuous state couples to a discrete state resulting in quantum interference that provides a transmission peak within a broad absorption profile the so-called electromagnetically induced transparency (EIT). In the field of plasmonic metamaterials, the sub-wavelength metallic structures play a role similar to atoms in nature. The interference of their near-field coupling at plasmonic resonance leads to a plasmon induced transparency (PIT) that is analogous to the EIT of atomic systems. A sensitive control of the PIT is crucial to a range of potential applications such as slowing light and biosensor. So far, the PIT phenomena often arise from the electric resonance, such as an electric dipole state coupled to an electric quadrupole state. Here we report the first three-dimensional photonic metamaterial consisting of an array of erected U-shape plasmonic gold nanostructures that exhibits PIT phenomenon with magnetic dipolar interaction between magnetic metamolecules. We further demonstrate using a numerical simulation that the coupling between the different excited pathways at an intermediate resonant wavelength allows for a π phase shift resulting in a destructive interference. A classical RLC circuit was also proposed to explain the coupling effects between the bright and dark modes of EIT-like electromagnetic spectra. This work paves a promising approach to achieve magnetic plasmon devices.
Optical image recognition of three-dimensional objects.
Poon, T C; Kim, T
1999-01-10
A three-dimensional (3-D) optical image-recognition technique is proposed and studied. The proposed technique is based on two-pupil optical heterodyne scanning and is capable of performing 3-D image recognition. A hologram of the 3-D reference object is first created and then is used to modulate spatially one of the pupils of the optical system; the other pupil is a point source. A 3-D target object to be recognized is then scanned in two dimensions by optical beams modulated by the two pupils. The result of the two-dimensional scan pattern effectively displays the correlation of the holographic information of the 3-D reference object and that of the 3-D target object. A strong correlation peak results if the two pieces of the holographic information are matched. We analyze the proposed technique and thereby lay a theoretical foundation for optical implementations of the idea. Finally, computer simulations are performed to verify the proposed idea.
Modern methods of analysis for three-dimensional orientational data
Davis, Joshua R.; Titus, Sarah J.
2017-03-01
Structural geology studies commonly include data about orientations of objects in space. By ;orientation; we mean not just a single direction, such as a foliation pole or the long axis of an ellipsoid, but a complete three-dimensional orientation of a body such as a foliation-lineation pair, a fold, an ellipsoid, etc. Over the past four decades, researchers in various fields have developed theory and algorithms for dealing with such data. In this paper, we explain how to apply orientation statistics to common geologic data types. We review plotting systems, measures of location and dispersion, inference (confidence/credible regions and hypothesis tests) for population means, and regression. We pay special attention to methods that work for small sample sizes and widely dispersed data. Our original contributions include a concept of Kamb contouring for orientations, a technique for handling anisotropy in confidence/credible regions, and large-scale numerical experiments on the performance of various inference methods. We conclude with a detailed study of foliation-lineations from the western Idaho shear zone, using statistical results to argue that the data are not consistent with a published model for them.
Three dimensional modelling of earthquake rupture cycles on frictional faults
Simpson, Guy; May, Dave
2017-04-01
We are developing an efficient MPI-parallel numerical method to simulate earthquake sequences on preexisting faults embedding within a three dimensional viscoelastic half-space. We solve the velocity form of the elasto(visco)dynamic equations using a continuous Galerkin Finite Element Method on an unstructured pentahedral mesh, which thus permits local spatial refinement in the vicinity of the fault. Friction sliding is coupled to the viscoelastic solid via rate- and state-dependent friction laws using the split-node technique. Our coupled formulation employs a picard-type non-linear solver with a fully implicit, first order accurate time integrator that utilises an adaptive time step that efficiently evolves the system through multiple seismic cycles. The implementation leverages advanced parallel solvers, preconditioners and linear algebra from the Portable Extensible Toolkit for Scientific Computing (PETSc) library. The model can treat heterogeneous frictional properties and stress states on the fault and surrounding solid as well as non-planar fault geometries. Preliminary tests show that the model successfully reproduces dynamic rupture on a vertical strike-slip fault in a half-space governed by rate-state friction with the ageing law.
Volumetric three-dimensional display system with rasterization hardware
Favalora, Gregg E.; Dorval, Rick K.; Hall, Deirdre M.; Giovinco, Michael; Napoli, Joshua
2001-06-01
An 8-color multiplanar volumetric display is being developed by Actuality Systems, Inc. It will be capable of utilizing an image volume greater than 90 million voxels, which we believe is the greatest utilizable voxel set of any volumetric display constructed to date. The display is designed to be used for molecular visualization, mechanical CAD, e-commerce, entertainment, and medical imaging. As such, it contains a new graphics processing architecture, novel high-performance line- drawing algorithms, and an API similar to a current standard. Three-dimensional imagery is created by projecting a series of 2-D bitmaps ('image slices') onto a diffuse screen that rotates at 600 rpm. Persistence of vision fuses the slices into a volume-filling 3-D image. A modified three-panel Texas Instruments projector provides slices at approximately 4 kHz, resulting in 8-color 3-D imagery comprised of roughly 200 radially-disposed slices which are updated at 20 Hz. Each slice has a resolution of 768 by 768 pixels, subtending 10 inches. An unusual off-axis projection scheme incorporating tilted rotating optics is used to maintain good focus across the projection screen. The display electronics includes a custom rasterization architecture which converts the user's 3- D geometry data into image slices, as well as 6 Gbits of DDR SDRAM graphics memory.