Informatics solutions for Three-dimensional visualization in real time

International Nuclear Information System (INIS)

Guzman Montoto, Jose Ignacio

2002-01-01

The advances reached in the development of the hardware and in the methods of acquisition of data like tomographic scanners and systems of analysis of images, have allowed obtaining geometric models of biomedical elements with the property of being manipulated through the three-dimensional visualization (3D). Nowadays, this visualization embraces from biological applications, including analysis of structures and its functional relationships, until medical applications that include anatomical accuracies and the planning or the training for complex surgical operations. This work proposes computer solutions to satisfy visualization requirements in real time. The developed algorithms are contained in a graphic library that will facilitate the development of future works. The obtained results allow facing current problems of three-dimensional representation of complex surfaces, realism is reached in the images and they have possible application in bioinformatics and medicine

Three-dimensional microbubble streaming flows

Science.gov (United States)

Rallabandi, Bhargav; Marin, Alvaro; Rossi, Massimiliano; Kaehler, Christian; Hilgenfeldt, Sascha

2014-11-01

Streaming due to acoustically excited bubbles has been used successfully for applications such as size-sorting, trapping and focusing of particles, as well as fluid mixing. Many of these applications involve the precise control of particle trajectories, typically achieved using cylindrical bubbles, which establish planar flows. Using astigmatic particle tracking velocimetry (APTV), we show that, while this two-dimensional picture is a useful description of the flow over short times, a systematic three-dimensional flow structure is evident over long time scales. We demonstrate that this long-time three-dimensional fluid motion can be understood through asymptotic theory, superimposing secondary axial flows (induced by boundary conditions at the device walls) onto the two-dimensional description. This leads to a general framework that describes three-dimensional flows in confined microstreaming systems, guiding the design of applications that profit from minimizing or maximizing these effects.

Recurrence relations and time evolution in the three-dimensional Sawada model

International Nuclear Information System (INIS)

Lee, M.H.; Hong, J.

1984-01-01

Time-dependent behavior of the three-dimensional Sawada model is obtained by a method of recurrence relations. Exactly calculated quantities are the time evolution of the density-fluctuation operator and its random force. As an application, their linear coefficients, the relaxation and memory functions are used to obtain certain dynamic quantities, e.g., the mobility

Research overview of real-time monitoring system for micro leak of three-dimensional pipe network

Directory of Open Access Journals (Sweden)

Shaofeng WANG

2016-04-01

Full Text Available Aiming at the key technical problems encountered by domestic and foreign scholars in building the real-time monitoring system for the micro leak of three-dimensional pipe networks, the paper classifies the problems into three aspects: 1 in the extraction of fault signal frequency, how to avoid the effect of the mixed echo stack and improve the delay estimation accuracy of the correlation; 2 in network bifurcation structure, how to discern the signal propagation path, and how to locate the leak source; 3 under the uncertainly delay in transmitting and receiving information data, how to ensure the time synchronization accuracy of the real-time monitoring system for the three-dimensional pipe network leakage. Through the comparison of the monitoring technologies for the pipe network leakage at home and abroad, it shows that the acoustic emission sensor network based three-dimensional pipeline leak real-time monitoring has great advantages in detecting the weak leakage of flammable and explosive gas/liquid transportation pipelines.

The ''three-dimensional time'' equation

International Nuclear Information System (INIS)

Pappas, P.T.; Athens Univ.

1979-01-01

The connection of the proper time between two observers is found within the six dimensional formalism. Small quantitative differences emerge from the GLT-combinations of rotations and SLT-boosts, but not from the SLT alone. It is also shown how to embed R 4 into R 6 . Transforming R 6 , transformations of R 4 arise which leave C constant and conform to a natural definition of ''parallelism'' -given. (author)

Quantitative assessment of primary mitral regurgitation using left ventricular volumes obtained with new automated three-dimensional transthoracic echocardiographic software: A comparison with 3-Tesla cardiac magnetic resonance.

Science.gov (United States)

Levy, Franck; Marechaux, Sylvestre; Iacuzio, Laura; Schouver, Elie Dan; Castel, Anne Laure; Toledano, Manuel; Rusek, Stephane; Dor, Vincent; Tribouilloy, Christophe; Dreyfus, Gilles

2018-03-30

Quantitative assessment of primary mitral regurgitation (MR) using left ventricular (LV) volumes obtained with three-dimensional transthoracic echocardiography (3D TTE) recently showed encouraging results. Nevertheless, 3D TTE is not incorporated into everyday practice, as current LV chamber quantification software products are time consuming. To investigate the accuracy and reproducibility of new automated fast 3D TTE software (HeartModel A.I. ; Philips Healthcare, Andover, MA, USA) for the quantification of LV volumes and MR severity in patients with isolated degenerative primary MR; and to compare regurgitant volume (RV) obtained with 3D TTE with a cardiac magnetic resonance (CMR) reference. Fifty-three patients (37 men; mean age 64±12 years) with at least mild primary isolated MR, and having comprehensive 3D TTE and CMR studies within 24h, were eligible for inclusion. MR RV was calculated using the proximal isovelocity surface area (PISA) method and the volumetric method (total LV stroke volume minus aortic stroke volume) with either CMR or 3D TTE. Inter- and intraobserver reproducibility of 3D TTE was excellent (coefficient of variation≤10%) for LV volumes. MR RV was similar using CMR and 3D TTE (57±23mL vs 56±28mL; P=0.22), but was significantly higher using the PISA method (69±30mL; P<0.05 compared with CMR and 3D TTE). The PISA method consistently overestimated MR RV compared with CMR (bias 12±21mL), while no significant bias was found between 3D TTE and CMR (bias 2±14mL). Concordance between echocardiography and CMR was higher using 3D TTE MR grading (intraclass correlation coefficient [ICC]=0.89) than with PISA MR grading (ICC=0.78). Complete agreement with CMR grading was more frequent with 3D TTE than with the PISA method (76% vs 63%). 3D TTE RV assessment using the new generation of automated software correlates well with CMR in patients with isolated degenerative primary MR. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Three-dimensional, three-component wall-PIV

Science.gov (United States)

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

2010-06-01

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

Accuracy of three-dimensional seismic ground response analysis in time domain using nonlinear numerical simulations

Science.gov (United States)

Liang, Fayun; Chen, Haibing; Huang, Maosong

2017-07-01

To provide appropriate uses of nonlinear ground response analysis for engineering practice, a three-dimensional soil column with a distributed mass system and a time domain numerical analysis were implemented on the OpenSees simulation platform. The standard mesh of a three-dimensional soil column was suggested to be satisfied with the specified maximum frequency. The layered soil column was divided into multiple sub-soils with a different viscous damping matrix according to the shear velocities as the soil properties were significantly different. It was necessary to use a combination of other one-dimensional or three-dimensional nonlinear seismic ground analysis programs to confirm the applicability of nonlinear seismic ground motion response analysis procedures in soft soil or for strong earthquakes. The accuracy of the three-dimensional soil column finite element method was verified by dynamic centrifuge model testing under different peak accelerations of the earthquake. As a result, nonlinear seismic ground motion response analysis procedures were improved in this study. The accuracy and efficiency of the three-dimensional seismic ground response analysis can be adapted to the requirements of engineering practice.

A method for real-time three-dimensional vector velocity imaging

DEFF Research Database (Denmark)

Jensen, Jørgen Arendt; Nikolov, Svetoslav

2003-01-01

The paper presents an approach for making real-time three-dimensional vector flow imaging. Synthetic aperture data acquisition is used, and the data is beamformed along the flow direction to yield signals usable for flow estimation. The signals are cross-related to determine the shift in position...... are done using 16 × 16 = 256 elements at a time and the received signals from the same elements are sampled. Access to the individual elements is done through 16-to-1 multiplexing, so that only a 256 channels transmitting and receiving system are needed. The method has been investigated using Field II...

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-dimensional liver motion tracking using real-time two-dimensional MRI.

Science.gov (United States)

Brix, Lau; Ringgaard, Steffen; Sørensen, Thomas Sangild; Poulsen, Per Rugaard

2014-04-01

Combined magnetic resonance imaging (MRI) systems and linear accelerators for radiotherapy (MR-Linacs) are currently under development. MRI is noninvasive and nonionizing and can produce images with high soft tissue contrast. However, new tracking methods are required to obtain fast real-time spatial target localization. This study develops and evaluates a method for tracking three-dimensional (3D) respiratory liver motion in two-dimensional (2D) real-time MRI image series with high temporal and spatial resolution. The proposed method for 3D tracking in 2D real-time MRI series has three steps: (1) Recording of a 3D MRI scan and selection of a blood vessel (or tumor) structure to be tracked in subsequent 2D MRI series. (2) Generation of a library of 2D image templates oriented parallel to the 2D MRI image series by reslicing and resampling the 3D MRI scan. (3) 3D tracking of the selected structure in each real-time 2D image by finding the template and template position that yield the highest normalized cross correlation coefficient with the image. Since the tracked structure has a known 3D position relative to each template, the selection and 2D localization of a specific template translates into quantification of both the through-plane and in-plane position of the structure. As a proof of principle, 3D tracking of liver blood vessel structures was performed in five healthy volunteers in two 5.4 Hz axial, sagittal, and coronal real-time 2D MRI series of 30 s duration. In each 2D MRI series, the 3D localization was carried out twice, using nonoverlapping template libraries, which resulted in a total of 12 estimated 3D trajectories per volunteer. Validation tests carried out to support the tracking algorithm included quantification of the breathing induced 3D liver motion and liver motion directionality for the volunteers, and comparison of 2D MRI estimated positions of a structure in a watermelon with the actual positions. Axial, sagittal, and coronal 2D MRI series

Three-dimensional liver motion tracking using real-time two-dimensional MRI

Energy Technology Data Exchange (ETDEWEB)

Brix, Lau, E-mail: lau.brix@stab.rm.dk [Department of Procurement and Clinical Engineering, Region Midt, Olof Palmes Allé 15, 8200 Aarhus N, Denmark and MR Research Centre, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Ringgaard, Steffen [MR Research Centre, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Sørensen, Thomas Sangild [Department of Computer Science, Aarhus University, Aabogade 34, 8200 Aarhus N, Denmark and Department of Clinical Medicine, Aarhus University, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Poulsen, Per Rugaard [Department of Clinical Medicine, Aarhus University, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark and Department of Oncology, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C (Denmark)

2014-04-15

Purpose: Combined magnetic resonance imaging (MRI) systems and linear accelerators for radiotherapy (MR-Linacs) are currently under development. MRI is noninvasive and nonionizing and can produce images with high soft tissue contrast. However, new tracking methods are required to obtain fast real-time spatial target localization. This study develops and evaluates a method for tracking three-dimensional (3D) respiratory liver motion in two-dimensional (2D) real-time MRI image series with high temporal and spatial resolution. Methods: The proposed method for 3D tracking in 2D real-time MRI series has three steps: (1) Recording of a 3D MRI scan and selection of a blood vessel (or tumor) structure to be tracked in subsequent 2D MRI series. (2) Generation of a library of 2D image templates oriented parallel to the 2D MRI image series by reslicing and resampling the 3D MRI scan. (3) 3D tracking of the selected structure in each real-time 2D image by finding the template and template position that yield the highest normalized cross correlation coefficient with the image. Since the tracked structure has a known 3D position relative to each template, the selection and 2D localization of a specific template translates into quantification of both the through-plane and in-plane position of the structure. As a proof of principle, 3D tracking of liver blood vessel structures was performed in five healthy volunteers in two 5.4 Hz axial, sagittal, and coronal real-time 2D MRI series of 30 s duration. In each 2D MRI series, the 3D localization was carried out twice, using nonoverlapping template libraries, which resulted in a total of 12 estimated 3D trajectories per volunteer. Validation tests carried out to support the tracking algorithm included quantification of the breathing induced 3D liver motion and liver motion directionality for the volunteers, and comparison of 2D MRI estimated positions of a structure in a watermelon with the actual positions. Results: Axial, sagittal

Three-dimensional liver motion tracking using real-time two-dimensional MRI

International Nuclear Information System (INIS)

Brix, Lau; Ringgaard, Steffen; Sørensen, Thomas Sangild; Poulsen, Per Rugaard

2014-01-01

Purpose: Combined magnetic resonance imaging (MRI) systems and linear accelerators for radiotherapy (MR-Linacs) are currently under development. MRI is noninvasive and nonionizing and can produce images with high soft tissue contrast. However, new tracking methods are required to obtain fast real-time spatial target localization. This study develops and evaluates a method for tracking three-dimensional (3D) respiratory liver motion in two-dimensional (2D) real-time MRI image series with high temporal and spatial resolution. Methods: The proposed method for 3D tracking in 2D real-time MRI series has three steps: (1) Recording of a 3D MRI scan and selection of a blood vessel (or tumor) structure to be tracked in subsequent 2D MRI series. (2) Generation of a library of 2D image templates oriented parallel to the 2D MRI image series by reslicing and resampling the 3D MRI scan. (3) 3D tracking of the selected structure in each real-time 2D image by finding the template and template position that yield the highest normalized cross correlation coefficient with the image. Since the tracked structure has a known 3D position relative to each template, the selection and 2D localization of a specific template translates into quantification of both the through-plane and in-plane position of the structure. As a proof of principle, 3D tracking of liver blood vessel structures was performed in five healthy volunteers in two 5.4 Hz axial, sagittal, and coronal real-time 2D MRI series of 30 s duration. In each 2D MRI series, the 3D localization was carried out twice, using nonoverlapping template libraries, which resulted in a total of 12 estimated 3D trajectories per volunteer. Validation tests carried out to support the tracking algorithm included quantification of the breathing induced 3D liver motion and liver motion directionality for the volunteers, and comparison of 2D MRI estimated positions of a structure in a watermelon with the actual positions. Results: Axial, sagittal

Multi-particle three-dimensional coordinate estimation in real-time optical manipulation

DEFF Research Database (Denmark)

Dam, Jeppe Seidelin; Perch-Nielsen, Ivan R.; Palima, Darwin

2009-01-01

We have previously shown how stereoscopic images can be obtained in our three-dimensional optical micromanipulation system [J. S. Dam et al, Opt. Express 16, 7244 (2008)]. Here, we present an extension and application of this principle to automatically gather the three-dimensional coordinates for...

Numerical method for solving the three-dimensional time-dependent neutron diffusion equation

International Nuclear Information System (INIS)

Khaled, S.M.; Szatmary, Z.

2005-01-01

A numerical time-implicit method has been developed for solving the coupled three-dimensional time-dependent multi-group neutron diffusion and delayed neutron precursor equations. The numerical stability of the implicit computation scheme and the convergence of the iterative associated processes have been evaluated. The computational scheme requires the solution of large linear systems at each time step. For this purpose, the point over-relaxation Gauss-Seidel method was chosen. A new scheme was introduced instead of the usual source iteration scheme. (author)

Application of a real-time three-dimensional navigation system to various oral and maxillofacial surgical procedures.

Science.gov (United States)

Ohba, Seigo; Yoshimura, Hitoshi; Ishimaru, Kyoko; Awara, Kousuke; Sano, Kazuo

2015-09-01

The aim of this study was to confirm the effectiveness of a real-time three-dimensional navigation system for use during various oral and maxillofacial surgeries. Five surgeries were performed with this real-time three-dimensional navigation system. For mandibular surgery, patients wore acrylic surgical splints when they underwent computed tomography examinations and the operation to maintain the mandibular position. The incidence of complications during and after surgery was assessed. No connection with the nasal cavity or maxillary sinus was observed at the maxilla during the operation. The inferior alveolar nerve was not injured directly, and any paresthesia around the lower lip and mental region had disappeared within several days after the surgery. In both maxillary and mandibular cases, there was no abnormal hemorrhage during or after the operation. Real-time three-dimensional computer-navigated surgery allows minimally invasive, safe procedures to be performed with precision. It results in minimal complications and early recovery.

Transthoracic ultrasound guided balloon dilation of cor triatriatum dexter in 2 Rottweiler puppies.

Science.gov (United States)

Birettoni, F; Caivano, D; Bufalari, A; Giorgi, M E; Miglio, A; Paradies, P; Porciello, F

2016-12-01

Balloon dilation was performed in two Rottweiler puppies with cor triatriatum dexter and clinical signs of ascites using transthoracic echocardiographic guidance. The dogs were positioned on a standard echocardiography table in right lateral recumbency, and guide wires and balloon catheters were imaged by echocardiographic views optimized to allow visualization of the defect. The procedures were performed successfully without complications and clinical signs were resolved completely in both cases. Guide wires and balloon catheters appeared hyperechoic on transthoracic echocardiography image and could be clearly monitored and guided in real-time. These two cases demonstrate that it is possible to perform balloon catheter dilation of cor triatriatum dexter under transthoracic guidance alone. Copyright © 2016 Elsevier B.V. All rights reserved.

(Weakly) three-dimensional caseology

International Nuclear Information System (INIS)

Pomraning, G.C.

1996-01-01

The singular eigenfunction technique of Case for solving one-dimensional planar symmetry linear transport problems is extended to a restricted class of three-dimensional problems. This class involves planar geometry, but with forcing terms (either boundary conditions or internal sources) which are weakly dependent upon the transverse spatial variables. Our analysis involves a singular perturbation about the classic planar analysis, and leads to the usual Case discrete and continuum modes, but modulated by weakly dependent three-dimensional spatial functions. These functions satisfy parabolic differential equations, with a different diffusion coefficient for each mode. Representative one-speed time-independent transport problems are solved in terms of these generalised Case eigenfunctions. Our treatment is very heuristic, but may provide an impetus for more rigorous analysis. (author)

Three Dimensional Polarimetric Neutron Tomography of Magnetic Fields

DEFF Research Database (Denmark)

Sales, Morten; Strobl, Markus; Shinohara, Takenao

2018-01-01

Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the first time successfully demonstrated a technique capable of measuring and reconstructing three dimensional magnetic field strengths and directions unobtrusively and non-destructively wi......Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the first time successfully demonstrated a technique capable of measuring and reconstructing three dimensional magnetic field strengths and directions unobtrusively and non...... and reconstructed, thereby providing the proof-of-principle of a technique able to reveal hitherto unobtainable information on the magnetic fields in the bulk of materials and devices, due to a high degree of penetration into many materials, including metals, and the sensitivity of neutron polarisation to magnetic...... fields. The technique puts the potential of the ToF time structure of pulsed neutron sources to full use in order to optimise the recorded information quality and reduce measurement time....

Incremental value of live/real time three-dimensional transesophageal echocardiography over the two-dimensional technique in the assessment of primary cardiac malignant fibrous histiocytoma.

Science.gov (United States)

Gok, Gulay; Elsayed, Mahmoud; Thind, Munveer; Uygur, Begum; Abtahi, Firoozeh; Chahwala, Jugal R; Yıldırımtürk, Özlem; Kayacıoğlu, İlyas; Pehlivanoğlu, Seçkin; Nanda, Navin C

2015-07-01

We describe a case of primary cardiac malignant fibrous histiocytoma where live/real time three-dimensional transesophageal echocardiography added incremental value to the two-dimensional modalities. Specifically, the three-dimensional technique allowed us to delineate the true extent and infiltration of the tumor, to identify characteristics of the tumor mass suggestive of its malignant nature, and to quantitatively assess the total tumor burden. © 2015, Wiley Periodicals, Inc.

Three-dimensional multi-relaxation-time lattice Boltzmann front-tracking method for two-phase flow

International Nuclear Information System (INIS)

Xie Hai-Qiong; Zeng Zhong; Zhang Liang-Qi

2016-01-01

We developed a three-dimensional multi-relaxation-time lattice Boltzmann method for incompressible and immiscible two-phase flow by coupling with a front-tracking technique. The flow field was simulated by using an Eulerian grid, an adaptive unstructured triangular Lagrangian grid was applied to track explicitly the motion of the two-fluid interface, and an indicator function was introduced to update accurately the fluid properties. The surface tension was computed directly on a triangular Lagrangian grid, and then the surface tension was distributed to the background Eulerian grid. Three benchmarks of two-phase flow, including the Laplace law for a stationary drop, the oscillation of a three-dimensional ellipsoidal drop, and the drop deformation in a shear flow, were simulated to validate the present model. (paper)

Three-dimensional magnetospheric equilibrium with isotropic pressure

International Nuclear Information System (INIS)

Cheng, C.Z.

1995-05-01

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

A heat conduction simulator to estimate lung temperature distribution during percutaneous transthoracic cryoablation for lung cancer

International Nuclear Information System (INIS)

Futami, Hikaru; Arai, Tsunenori; Yashiro, Hideki; Nakatsuka, Seishi; Kuribayashi, Sachio; Izumi, Youtaro; Tsukada, Norimasa; Kawamura, Masafumi

2006-01-01

To develop an evaluation method for the curative field when using X-ray CT imaging during percutaneous transthoracic cryoablation for lung cancer, we constructed a finite-element heat conduction simulator to estimate temperature distribution in the lung during cryo-treatment. We calculated temperature distribution using a simple two-dimensional finite element model, although the actual temperature distribution spreads in three dimensions. Temperature time-histories were measured within 10 minutes using experimental ex vivo and in vivo lung cryoablation conditions. We adjusted specific heat and thermal conductivity in the heat conduction calculation and compared them with measured temperature time-histories ex vivo. Adjusted lung specific heat was 3.7 J/ (g·deg C) for unfrozen lung and 1.8 J/ (g·deg C) for frozen lung. Adjusted lung thermal conductivity in our finite element model fitted proportionally to the exponential function of lung density. We considered the heat input by blood flow circulation and metabolic heat when we calculated the temperature time-histories during in vivo cryoablation of the lung. We assumed that the blood flow varies in inverse proportion to the change in blood viscosity up to the maximum blood flow predicted from cardiac output. Metabolic heat was set as heat generation in the calculation. The measured temperature time-histories of in vivo cryoablation were then estimated with an accuracy of ±3 deg C when calculated based on this assumption. Therefore, we successfully constructed a two-dimensional heat conduction simulator that is capable of estimating temperature distribution in the lung at the time of first freezing during cryoablation. (author)

FAST: a three-dimensional time-dependent FEL simulation code

International Nuclear Information System (INIS)

Saldin, E.L.; Schneidmiller, E.A.; Yurkov, M.V.

1999-01-01

In this report we briefly describe the three-dimensional, time-dependent FEL simulation code FAST. The equations of motion of the particles and Maxwell's equations are solved simultaneously taking into account the slippage effect. Radiation fields are calculated using an integral solution of Maxwell's equations. A special technique has been developed for fast calculations of the radiation field, drastically reducing the required CPU time. As a result, the developed code allows one to use a personal computer for time-dependent simulations. The code allows one to simulate the radiation from the electron bunch of any transverse and longitudinal bunch shape; to simulate simultaneously an external seed with superimposed noise in the electron beam; to take into account energy spread in the electron beam and the space charge fields; and to simulate a high-gain, high-efficiency FEL amplifier with a tapered undulator. It is important to note that there are no significant memory limitations in the developed code and an electron bunch of any length can be simulated

Application of three-dimensional CT reconstruction cranioplasty

International Nuclear Information System (INIS)

Yan Shuli; Yun Yongxing; Wan Kunming; Qiu Jian

2011-01-01

Objective: To study the application of three-dimensional CT reconstruction in cranioplasty. Methods: 46 patients with skull defect were divided into two group. One group underwent CT examination and three-dimensional reconstruction, and then the Titanium nets production company manufactured corresponding titanium meshes were shaped those data before the operation. The other group received traditional operation in which titanium meshes were shaped during operation. The average time of operation were compared. Results: The average time of operation of the first group is 86.6±13.6 mins, and that of the second group is 115±15.0 mins. The difference of average operation time between the two groups was statistically significant. Conclusion: Three-dimensional CT reconstruction techniques contribute to shorten the average operation time, reduce the intensity of neurosurgeon's work and the patien's risk. (authors)

Polarization dynamics and polarization time of random three-dimensional electromagnetic fields

International Nuclear Information System (INIS)

Voipio, Timo; Setaelae, Tero; Shevchenko, Andriy; Friberg, Ari T.

2010-01-01

We investigate the polarization dynamics of random, stationary three-dimensional (3D) electromagnetic fields. For analyzing the time evolution of the instantaneous polarization state, two intensity-normalized polarization autocorrelation functions are introduced, one based on a geometric approach with the Poincare vectors and the other on energy considerations with the Jones vectors. Both approaches lead to the same conclusions on the rate and strength of the polarization dynamics and enable the definition of a polarization time over which the state of polarization remains essentially unchanged. For fields obeying Gaussian statistics, the two correlation functions are shown to be expressible in terms of quantities characterizing partial 3D polarization and electromagnetic coherence. The 3D degree of polarization is found to have the same meaning in the 3D polarization dynamics as the usual two-dimensional (2D) degree of polarization does with planar fields. The formalism is demonstrated with several examples, and it is expected to be useful in applications dealing with polarization fluctuations of 3D light.

Transthoracic versus transhiatal esophagectomy – influence on patient survival

Directory of Open Access Journals (Sweden)

Mariusz Łochowski

2016-12-01

Full Text Available Aim: To evaluate the survival of patients after surgery of the esophagus/cardia using the transthoracic and transhiatal methods. Material and methods : In the years 2007–2011, 102 patients were radically treated for cancer of the esophagus/cardia: 24 women and 78 men at the average age of 59.5. There were 38 transthoracic procedures and 64 transhiatal procedures. All patients had a conduit made from the stomach, led through lodges in the esophagus and combined with the stump of the esophagus in the neck following the Collard method. Two-pole lymphadenectomies were performed in all patients. Results: Patients after transthoracic procedures had statistically more (p < 0.05 lymph nodes removed than patients after transhiatal procedures. The 5-year survival rates in transhiatal and transthoracic procedures did not statistically differ, being 8% and 0% respectively. The length of patient survival was influenced by metastases in the nearby lymph nodes (p < 0.0001 and the presence of adenocarcinoma. Conclusions : Surgical access (transhiatal and transthoracic surgery does not affect the 5-year survival rates. Transhiatal surgery allows a greater number of lymph nodes to be removed. The main factor influencing the 5-year survival rate is the presence of metastases in the nearby lymph nodes.

A case of complete double aortic arch visualized by transthoracic echocardiography.

Science.gov (United States)

Saito, Naka; Kato, Shingo; Saito, Noritaka; Nakachi, Tatsuya; Fukui, Kazuki; Iwasawa, Tae; Kosuge, Masami; Kimura, Kazuo

2017-08-01

A case of double aortic arch that was well visualized using transthoracic echocardiography is reported. A 38-year-old man underwent transthoracic echocardiography for the evaluation of dyspnea. A suprasternal view of transthoracic echocardiography showed the ascending aorta bifurcate to left and right aortic arches, with blood flow from the ascending aorta to bilateral aortic arches. The diagnosis of right side-dominant double aortic arch was made, and the patient's symptom was conceivably related to compression of the trachea due to a vascular ring. This report indicates the potential usefulness of transthoracic echocardiography for noninvasive detection of double aortic arch in adults. © 2017, Wiley Periodicals, Inc.

Three-dimensional topological insulators and bosonization

Energy Technology Data Exchange (ETDEWEB)

Cappelli, Andrea [INFN, Sezione di Firenze,Via G. Sansone 1, 50019 Sesto Fiorentino - Firenze (Italy); Randellini, Enrico [INFN, Sezione di Firenze,Via G. Sansone 1, 50019 Sesto Fiorentino - Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze,Via G. Sansone 1, 50019 Sesto Fiorentino - Firenze (Italy); Sisti, Jacopo [Scuola Internazionale Superiore di Studi Avanzati (SISSA),Via Bonomea 265, 34136 Trieste (Italy)

2017-05-25

Massless excitations at the surface of three-dimensional time-reversal invariant topological insulators possess both fermionic and bosonic descriptions, originating from band theory and hydrodynamic BF theory, respectively. We analyze the corresponding field theories of the Dirac fermion and compactified boson and compute their partition functions on the three-dimensional torus geometry. We then find some non-dynamic exact properties of bosonization in (2+1) dimensions, regarding fermion parity and spin sectors. Using these results, we extend the Fu-Kane-Mele stability argument to fractional topological insulators in three dimensions.

Three-dimensional ICT reconstruction

International Nuclear Information System (INIS)

Zhang Aidong; Li Ju; Chen Fa; Sun Lingxia

2005-01-01

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

Three-dimensional ICT reconstruction

International Nuclear Information System (INIS)

Zhang Aidong; Li Ju; Chen Fa; Sun Lingxia

2004-01-01

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

Real-time three-dimensional surface measurement by color encoded light projection

International Nuclear Information System (INIS)

Chen, S. Y.; Li, Y. F.; Guan, Q.; Xiao, G.

2006-01-01

Existing noncontact methods for surface measurement suffer from the disadvantages of poor reliability, low scanning speed, or high cost. The authors present a method for real-time three-dimensional data acquisition by a color-coded vision sensor composed of common components. The authors use a digital projector controlled by computer to generate desired color light patterns. The unique indexing of the light codes is a key problem and is solved in this study so that surface perception can be performed with only local pattern analysis of the neighbor color codes in a single image. Experimental examples and performance analysis are provided

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 analysis of craniofacial bones using three-dimensional computer tomography

International Nuclear Information System (INIS)

Ono, Ichiro; Ohura, Takehiko; Kimura, Chu

1989-01-01

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

Three dimensional strained semiconductors

Science.gov (United States)

Voss, Lars; Conway, Adam; Nikolic, Rebecca J.; Leao, Cedric Rocha; Shao, Qinghui

2016-11-08

In one embodiment, an apparatus includes a three dimensional structure comprising a semiconductor material, and at least one thin film in contact with at least one exterior surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the three dimensional structure. In another embodiment, a method includes forming a three dimensional structure comprising a semiconductor material, and depositing at least one thin film on at least one surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the structure.

The factor analysis of the incidence of pneumothorax after CT-guided transthoracic needle aspiration biopsy

International Nuclear Information System (INIS)

Zhong Tao; Yu Hongguang; Wang Yong; Yang Sifu; Wang Xiaoxuan

2007-01-01

Objective: To analyze the impact of multiple factors on the incidence of pneumothorax associated with CT-guided transthoracic needle aspiration biopsy. Methods: The sign of pneumothorax after 162 cases (lesion diameter from 1 cm to 6 cm) CT-guided transthoracic needle aspiration biopsy was observed and its relationship with multivariate factors were analyzed by multivariate logistic regression model. Results: Thirty-two cases presented pneumothorax accounting for 19. 8%. Single variate analysis showed that the sign of pneumothorax related to intercurrent COPD, distance from lesion and chest wall, needle dwelling time and lesion diameter. 67 patients of intercurrent COPD with postoperative pneumothorax occurred in 22 cases (32.8%); With respect to those having lesions close to the chest wall (48 cases), and the cases with the distance between the chest wall and lesions less than 2 cm (55 cases) and greater than 2 cm (59 cases), the postoperative pneumothorax occurred in 0, 14 (25.5%), 18 (30.5%) cases respectively; For those patients with needle in the chest residence time of less than 10 minutes (82 cases), 10-20 minutes (51 cases), more than 20 minutes (28 cases) after the occurrence of pneumothorax were 8 (9.6%), 10(19.6%), 14 (50%) cases respectively; In contrast, those with lesion diameter less than 2 cm (65 cases), 2-4 cm(52 cases), more than 4cm(45 cases) were 19 (29.2%), 8 (15.4%) and 5 (11.1% ) respectively. The multivariate logistic regression analysis showed that the prior three factor's were risk factors of pneumothorax (OR=4.652, 4.030, 2.855 respectively). Conclusions: To avoid the pneumothorax, caution must be taken with respect to CT-guided transthoracic needle aspiration biopsy, patients with intercurrent COPD, long distance between lesion and chest wall, and smaller lesion diameter. For operation the needle dwell time within thorax should be minimized. (authors)

Three-dimensional time-lapse velocity tomography of an underground longwall panel

Energy Technology Data Exchange (ETDEWEB)

Luxbacher, K.; Westman, E.; Swanson, P.; Karfakis, M. [Virginia Tech., Blacksburg, VA (United States). Dept. of Mining & Minerals Engineering

2008-06-15

Three-dimensional velocity tomograms were generated to image the stress redistribution around an underground coal longwall panel to produce a better understanding of the mechanisms that lead to ground failure, especially rockbursts. Mining-induced microseismic events provided passive sources for the three-dimensional velocity tomography. Surface-mounted geophones monitored microseismic activity for 18 days. Eighteen tomograms were generated and high-velocity regions correlated with high abutment stresses predicted by numerical modeling. Additionally, the high-velocity regions were observed to redistribute as the longwall face retreated, indicating that velocity tomography may be an appropriate technology for monitoring stress redistribution in underground mines.

Clinical assessment of transthoracic echocardiography skills: a generalizability study

DEFF Research Database (Denmark)

Nielsen, Dorte Guldbrand; O'Neill, Lotte; Jensen, Signe

2015-01-01

Context: Transthoracic echocardiography (TTE) is a widely used cardiac imaging technique that all cardiologists should be able to perform competently. Traditionally, TTE competence has been assessed by unstructured observation or in test situations separated from daily clinical practice. An objec......Context: Transthoracic echocardiography (TTE) is a widely used cardiac imaging technique that all cardiologists should be able to perform competently. Traditionally, TTE competence has been assessed by unstructured observation or in test situations separated from daily clinical practice....... An objective assessment instrument for TTE technical proficiency including a global rating score and a checklist score has previously been shown reliability and validity in a standardised setting. Objectives: As clinical test situations typically have several sources of error giving rise to variance in scores......, a more thorough examination of the generalizability of the test scores is needed. Methods Nine physicians performed a TTE scan on the same three patients. Then, two raters rated all 27 TTE scans using the TTE technical assessment in a fully crossed generalizability study. Estimated variance components...

Study of the nonlinear three-dimensional Debye screening in plasmas

International Nuclear Information System (INIS)

Lin Chang; Zhao Jinbao; Zhang Xiulian

2000-01-01

The nonlinear three-dimensional Debye screening in plasmas is investigated. New analytical solutions for the three-dimensional Poisson equation have been obtained for the nonlinear Debye potential for the first time. We derive exact analytical expression for the special case of the nonlinear three-dimensional Debye screening in plasmas. (orig.)

Usefulness of real-time three-dimensional ultrasonography in percutaneous nephrostomy: an animal study.

Science.gov (United States)

Hongzhang, Hong; Xiaojuan, Qin; Shengwei, Zhang; Feixiang, Xiang; Yujie, Xu; Haibing, Xiao; Gallina, Kazobinka; Wen, Ju; Fuqing, Zeng; Xiaoping, Zhang; Mingyue, Ding; Huageng, Liang; Xuming, Zhang

2018-05-17

To evaluate the effect of real-time three-dimensional (3D) ultrasonography (US) in guiding percutaneous nephrostomy (PCN). A hydronephrosis model was devised in which the ureters of 16 beagles were obstructed. The beagles were divided equally into groups 1 and 2. In group 1, the PCN was performed using real-time 3D US guidance, while in group 2 the PCN was guided using two-dimensional (2D) US. Visualization of the needle tract, length of puncture time and number of puncture times were recorded for the two groups. In group 1, score for visualization of the needle tract, length of puncture time and number of puncture times were 3, 7.3 ± 3.1 s and one time, respectively. In group 2, the respective results were 1.4 ± 0.5, 21.4 ± 5.8 s and 2.1 ± 0.6 times. The visualization of needle tract in group 1 was superior to that in group 2, and length of puncture time and number of puncture times were both lower in group 1 than in group 2. Real-time 3D US-guided PCN is superior to 2D US-guided PCN in terms of visualization of needle tract and the targeted pelvicalyceal system, leading to quick puncture. Real-time 3D US-guided puncture of the kidney holds great promise for clinical implementation in PCN. © 2018 The Authors BJU International © 2018 BJU International Published by John Wiley & Sons Ltd.

Generalized Runge-Kutta method for two- and three-dimensional space-time diffusion equations with a variable time step

International Nuclear Information System (INIS)

Aboanber, A.E.; Hamada, Y.M.

2008-01-01

An extensive knowledge of the spatial power distribution is required for the design and analysis of different types of current-generation reactors, and that requires the development of more sophisticated theoretical methods. Therefore, the need to develop new methods for multidimensional transient reactor analysis still exists. The objective of this paper is to develop a computationally efficient numerical method for solving the multigroup, multidimensional, static and transient neutron diffusion kinetics equations. A generalized Runge-Kutta method has been developed for the numerical integration of the stiff space-time diffusion equations. The method is fourth-order accurate, using an embedded third-order solution to arrive at an estimate of the truncation error for automatic time step control. In addition, the A(α)-stability properties of the method are investigated. The analyses of two- and three-dimensional benchmark problems as well as static and transient problems, demonstrate that very accurate solutions can be obtained with assembly-sized spatial meshes. Preliminary numerical evaluations using two- and three-dimensional finite difference codes showed that the presented generalized Runge-Kutta method is highly accurate and efficient when compared with other optimized iterative numerical and conventional finite difference methods

Three-dimensional discrete-time Lotka-Volterra models with an application to industrial clusters

Science.gov (United States)

Bischi, G. I.; Tramontana, F.

2010-10-01

We consider a three-dimensional discrete dynamical system that describes an application to economics of a generalization of the Lotka-Volterra prey-predator model. The dynamic model proposed is used to describe the interactions among industrial clusters (or districts), following a suggestion given by [23]. After studying some local and global properties and bifurcations in bidimensional Lotka-Volterra maps, by numerical explorations we show how some of them can be extended to their three-dimensional counterparts, even if their analytic and geometric characterization becomes much more difficult and challenging. We also show a global bifurcation of the three-dimensional system that has no two-dimensional analogue. Besides the particular economic application considered, the study of the discrete version of Lotka-Volterra dynamical systems turns out to be a quite rich and interesting topic by itself, i.e. from a purely mathematical point of view.

Acoustic Performance of a Real-Time Three-Dimensional Sound-Reproduction System

Science.gov (United States)

Faller, Kenneth J., II; Rizzi, Stephen A.; Aumann, Aric R.

2013-01-01

The Exterior Effects Room (EER) is a 39-seat auditorium at the NASA Langley Research Center and was built to support psychoacoustic studies of aircraft community noise. The EER has a real-time simulation environment which includes a three-dimensional sound-reproduction system. This system requires real-time application of equalization filters to compensate for spectral coloration of the sound reproduction due to installation and room effects. This paper describes the efforts taken to develop the equalization filters for use in the real-time sound-reproduction system and the subsequent analysis of the system s acoustic performance. The acoustic performance of the compensated and uncompensated sound-reproduction system is assessed for its crossover performance, its performance under stationary and dynamic conditions, the maximum spatialized sound pressure level it can produce from a single virtual source, and for the spatial uniformity of a generated sound field. Additionally, application examples are given to illustrate the compensated sound-reproduction system performance using recorded aircraft flyovers

Simulation of three-dimensional, time-dependent, incompressible flows by a finite element method

International Nuclear Information System (INIS)

Chan, S.T.; Gresho, P.M.; Lee, R.L.; Upson, C.D.

1981-01-01

A finite element model has been developed for simulating the dynamics of problems encountered in atmospheric pollution and safety assessment studies. The model is based on solving the set of three-dimensional, time-dependent, conservation equations governing incompressible flows. Spatial discretization is performed via a modified Galerkin finite element method, and time integration is carried out via the forward Euler method (pressure is computed implicitly, however). Several cost-effective techniques (including subcycling, mass lumping, and reduced Gauss-Legendre quadrature) which have been implemented are discussed. Numerical results are presented to demonstrate the applicability of the model

Two- and three-dimensional accuracy of dental impression materials: effects of storage time and moisture contamination.

Science.gov (United States)

Chandran, Deepa T; Jagger, Daryll C; Jagger, Robert G; Barbour, Michele E

2010-01-01

Dental impression materials are used to create an inverse replica of the dental hard and soft tissues, and are used in processes such as the fabrication of crowns and bridges. The accuracy and dimensional stability of impression materials are of paramount importance to the accuracy of fit of the resultant prosthesis. Conventional methods for assessing the dimensional stability of impression materials are two-dimensional (2D), and assess shrinkage or expansion between selected fixed points on the impression. In this study, dimensional changes in four impression materials were assessed using an established 2D and an experimental three-dimensional (3D) technique. The former involved measurement of the distance between reference points on the impression; the latter a contact scanning method for producing a computer map of the impression surface showing localised expansion, contraction and warpage. Dimensional changes were assessed as a function of storage times and moisture contamination comparable to that found in clinical situations. It was evident that dimensional changes observed using the 3D technique were not always apparent using the 2D technique, and that the former offers certain advantages in terms of assessing dimensional accuracy and predictability of impression methods. There are, however, drawbacks associated with 3D techniques such as the more time-consuming nature of the data acquisition and difficulty in statistically analysing the data.

A funnel shaped pannus formation above the mitral prosthetic valve diagnosed with real time three-dimensional echocardiography

Directory of Open Access Journals (Sweden)

Ezgi Polat Ocaklı

2017-09-01

Full Text Available Prosthetic valve obstruction due to pannus formation can be a life-threatening complication. We showed that real time three dimensional echocardiography has incremental value in diagnosing pannus localization and extent.

Extrapeural locating method: significance in CT-guided transthoracic pulmonary biopsy

International Nuclear Information System (INIS)

Tang Guangjian; Wang Rengui; Liu Jianxin; Sun Jingtao

2008-01-01

Objective: To evaluate the usefulness of extrapleural locating method in CT-guided transthoracic pulmonary biopsy to prevent or reduce the size of peumothorax. Methods: One hundred and fifteen cases of CT-guided transthoracic pulmonary biopsy with the pulmonary lesions not in direct contact with the pleura were selected. Of 115 cases, 46 were performed with extrapleural locating method (EPL) and 69 cases with lesion edge locating method (LEL). Taking the maximum distance between the partial and visceral pleura (MPVD) measured on the CT image after the procedure as the index of the volume of pneumothorax. The incidence and volume of pneumothorax of both groups were compared and statistically analysed with R x C Chi-Square test. The retention time of the biopsy needle in the lung parenchyma of the two group was documented and the average time was calculated in each group. Results: The incidence of pneumothorax was 45.7% (21/46), median 0.4 cm with EPL group, and 66.7% (46/69) and median 0.3cm with LEL group. When the distance between the lesion and pleura was equal or smaller than 2 cm (≤2cm), the incidence of pneumothorax was 39.4% (13/33) with EPL group and 73.2% (30/41) with LEL group, and the difference of incidence and volume of the pneumothorax between two groups was statistically significant(χ 2 =9.981, P=0.019). When the distance was larger than 2 cm (>2 cm), the incidence and volume of pneumothorax between two groups were not significant statistically. The average retention time of the biopsy needle in the lung parenchyma was (7.2 ± 1.8) s with EPL group and (58.3 ± 11.6) s with LEL group. Conclusion: The extrapleural locating method can reduce effectively the retention time of the biopsy needle in the lung parenchyma and the incidence and volume of pneumothorax in CT-guided transthoracic pulmonary biopsy. (authors)

Successful percutaneous coronary intervention significantly improves coronary sinus blood flow as assessed by transthoracic echocardiography.

Science.gov (United States)

Lyubarova, Radmila; Boden, William E; Fein, Steven A; Schulman-Marcus, Joshua; Torosoff, Mikhail

2018-06-01

Transthoracic echocardiography (TTE) has been used to assess coronary sinus blood flow (CSBF), which reflects total coronary arterial blood flow. Successful angioplasty is expected to improve coronary arterial blood flow. Changes in CSBF after percutaneous coronary intervention (PCI), as assessed by TTE, have not been systematically evaluated. TTE can be utilized to reflect increased CSBF after a successful, clinically indicated PCI. The study cohort included 31 patients (18 females, 62 ± 11 years old) referred for diagnostic cardiac catheterization for suspected coronary artery disease and possible PCI, when clinically indicated. All performed PCIs were successful, with good angiographic outcome. CSBF per cardiac cycle (mL/beat) was measured using transthoracic two-dimensional and Doppler flow imaging as the product of coronary sinus (CS) area and CS flow time-velocity integral. CSBF per minute (mL/min) was calculated as the product of heart rate and CSBF per cardiac cycle. In each patient, CSBF was assessed prospectively, before and after cardiac catheterization with and without clinically indicated PCI. Within- and between-group differences in CSBF before and after PCI were assessed using repeated measures analysis of variance. Technically adequate CSBF measurements were obtained in 24 patients (77%). In patients who did not undergo PCI, there was no significant change in CSBF (278.1 ± 344.1 versus 342.7 ± 248.5, p = 0.36). By contrast, among patients who underwent PCI, CSBF increased significantly (254.3 ± 194.7 versus 618.3 ± 358.5 mL/min, p < 0.01, p-interaction = 0.03). Other hemodynamic and echocardiographic parameters did not change significantly before and after cardiac catheterization in either treatment group. Transthoracic echocardiographic assessment can be employed to document CSBF changes after angioplasty. Future studies are needed to explore the clinical utility of this noninvasive metric.

Three-Dimensional Messages for Interstellar Communication

Science.gov (United States)

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.

Three-dimensional, automated, real-time video system for tracking limb motion in brain-machine interface studies.

Science.gov (United States)

Peikon, Ian D; Fitzsimmons, Nathan A; Lebedev, Mikhail A; Nicolelis, Miguel A L

2009-06-15

Collection and analysis of limb kinematic data are essential components of the study of biological motion, including research into biomechanics, kinesiology, neurophysiology and brain-machine interfaces (BMIs). In particular, BMI research requires advanced, real-time systems capable of sampling limb kinematics with minimal contact to the subject's body. To answer this demand, we have developed an automated video tracking system for real-time tracking of multiple body parts in freely behaving primates. The system employs high-contrast markers painted on the animal's joints to continuously track the three-dimensional positions of their limbs during activity. Two-dimensional coordinates captured by each video camera are combined and converted to three-dimensional coordinates using a quadratic fitting algorithm. Real-time operation of the system is accomplished using direct memory access (DMA). The system tracks the markers at a rate of 52 frames per second (fps) in real-time and up to 100fps if video recordings are captured to be later analyzed off-line. The system has been tested in several BMI primate experiments, in which limb position was sampled simultaneously with chronic recordings of the extracellular activity of hundreds of cortical cells. During these recordings, multiple computational models were employed to extract a series of kinematic parameters from neuronal ensemble activity in real-time. The system operated reliably under these experimental conditions and was able to compensate for marker occlusions that occurred during natural movements. We propose that this system could also be extended to applications that include other classes of biological motion.

Three-dimensional effects in fracture mechanics

International Nuclear Information System (INIS)

Benitez, F.G.

1991-01-01

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

Hydrogeophysical exploration of three-dimensional salinity anomalies with the time-domain electromagnetic method (TDEM)

DEFF Research Database (Denmark)

Bauer-Gottwein, Peter; Gondwe, Bibi Ruth Neuman; Christiansen, Lars

2010-01-01

Delta is presented. Evaporative salt enrichment causes a strong salinity anomaly under the island. We show that the TDEM field data cannot be interpreted in terms of standard one-dimensional layered-earth TDEM models, because of the strongly three-dimensional nature of the salinity anomaly. Three...

Three-Dimensional Flows

CERN Document Server

Araujo, Vitor; Viana, Marcelo

2010-01-01

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

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

Science.gov (United States)

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

2009-01-01

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

Three-dimensional instability of standing waves

Science.gov (United States)

Zhu, Qiang; Liu, Yuming; Yue, Dick K. P.

2003-12-01

We investigate the three-dimensional instability of finite-amplitude standing surface waves under the influence of gravity. The analysis employs the transition matrix (TM) approach and uses a new high-order spectral element (HOSE) method for computation of the nonlinear wave dynamics. HOSE is an extension of the original high-order spectral method (HOS) wherein nonlinear wave wave and wave body interactions are retained up to high order in wave steepness. Instead of global basis functions in HOS, however, HOSE employs spectral elements to allow for complex free-surface geometries and surface-piercing bodies. Exponential convergence of HOS with respect to the total number of spectral modes (for a fixed number of elements) and interaction order is retained in HOSE. In this study, we use TM-HOSE to obtain the stability of general three-dimensional perturbations (on a two-dimensional surface) on two classes of standing waves: plane standing waves in a rectangular tank; and radial/azimuthal standing waves in a circular basin. For plane standing waves, we confirm the known result of two-dimensional side-bandlike instability. In addition, we find a novel three-dimensional instability for base flow of any amplitude. The dominant component of the unstable disturbance is an oblique (standing) wave oriented at an arbitrary angle whose frequency is close to the (nonlinear) frequency of the original standing wave. This finding is confirmed by direct long-time simulations using HOSE which show that the nonlinear evolution leads to classical Fermi Pasta Ulam recurrence. For the circular basin, we find that, beyond a threshold wave steepness, a standing wave (of nonlinear frequency Omega) is unstable to three-dimensional perturbations. The unstable perturbation contains two dominant (standing-wave) components, the sum of whose frequencies is close to 2Omega. From the cases we consider, the critical wave steepness is found to generally decrease/increase with increasing radial

Transthoracic needle biopsy: factors effecting risk of pneumothorax

International Nuclear Information System (INIS)

Topal, Ugur; Ediz, Buelent

2003-01-01

Objective: to evaluate the factors that could effect the risk of pneumothorax in patients undergoing transthoracic biopsy. Material and methods: variables that could increase the risk of pneumothorax were evaluated in 453 CT-guided transthoracic biopsies. Factors were evaluated in two groups: (1) lesion related (presence of emphysema around the lesion, lesion depth, cavitation, presence of fissure/atelectasis and pleural tag in the needle trajectory); and (2) procedure related (biopsy type, needle size, number of passages, level of experience of the operator). All variables were analysed by χ 2 test and multivariate logistic regression statistics. Results: pneumothorax was developed in 85 (18.8%) out of 453 procedures. A chest tube was inserted in ten (11.7%) of them. Variables that were significantly associated with an increased risk of pneumothorax were depth of the lesion (P<0.001) and severity of the emphysema (P<0.01). Conclusion: the length of the lung parenchyma traversed during the biopsy is the predominant risk factor for pneumothorax in patients undergoing CT-guided transthoracic biopsy. The risk of pneumothorax was also increased with the severity of the emphysema around the lesion

Three-dimensional biomedical imaging

International Nuclear Information System (INIS)

Robb, R.A.

1985-01-01

Scientists in biomedical imaging provide researchers, physicians, and academicians with an understanding of the fundamental theories and practical applications of three-dimensional biomedical imaging methodologies. Succinct descriptions of each imaging modality are supported by numerous diagrams and illustrations which clarify important concepts and demonstrate system performance in a variety of applications. Comparison of the different functional attributes, relative advantages and limitations, complementary capabilities, and future directions of three-dimensional biomedical imaging modalities are given. Volume 1: Introductions to Three-Dimensional Biomedical Imaging Photoelectronic-Digital Imaging for Diagnostic Radiology. X-Ray Computed Tomography - Basic Principles. X-Ray Computed Tomography - Implementation and Applications. X-Ray Computed Tomography: Advanced Systems and Applications in Biomedical Research and Diagnosis. Volume II: Single Photon Emission Computed Tomography. Position Emission Tomography (PET). Computerized Ultrasound Tomography. Fundamentals of NMR Imaging. Display of Multi-Dimensional Biomedical Image Information. Summary and Prognostications

Three-dimensional neuroimaging

International Nuclear Information System (INIS)

Toga, A.W.

1990-01-01

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

CONFRONTING THREE-DIMENSIONAL TIME-DEPENDENT JET SIMULATIONS WITH HUBBLE SPACE TELESCOPE OBSERVATIONS

International Nuclear Information System (INIS)

Staff, Jan E.; Niebergal, Brian P.; Ouyed, Rachid; Pudritz, Ralph E.; Cai, Kai

2010-01-01

We perform state-of-the-art, three-dimensional, time-dependent simulations of magnetized disk winds, carried out to simulation scales of 60 AU, in order to confront optical Hubble Space Telescope observations of protostellar jets. We 'observe' the optical forbidden line emission produced by shocks within our simulated jets and compare these with actual observations. Our simulations reproduce the rich structure of time-varying jets, including jet rotation far from the source, an inner (up to 400 km s -1 ) and outer (less than 100 km s -1 ) component of the jet, and jet widths of up to 20 AU in agreement with observed jets. These simulations when compared with the data are able to constrain disk wind models. In particular, models featuring a disk magnetic field with a modest radial spatial variation across the disk are favored.

A DETERMINISTIC METHOD FOR TRANSIENT, THREE-DIMENSIONAL NUETRON TRANSPORT

International Nuclear Information System (INIS)

S. GOLUOGLU, C. BENTLEY, R. DEMEGLIO, M. DUNN, K. NORTON, R. PEVEY I.SUSLOV AND H.L. DODDS

1998-01-01

A deterministic method for solving the time-dependent, three-dimensional Boltzmam transport equation with explicit representation of delayed neutrons has been developed and evaluated. The methodology used in this study for the time variable of the neutron flux is known as the improved quasi-static (IQS) method. The position, energy, and angle-dependent neutron flux is computed deterministically by using the three-dimensional discrete ordinates code TORT. This paper briefly describes the methodology and selected results. The code developed at the University of Tennessee based on this methodology is called TDTORT. TDTORT can be used to model transients involving voided and/or strongly absorbing regions that require transport theory for accuracy. This code can also be used to model either small high-leakage systems, such as space reactors, or asymmetric control rod movements. TDTORT can model step, ramp, step followed by another step, and step followed by ramp type perturbations. It can also model columnwise rod movement can also be modeled. A special case of columnwise rod movement in a three-dimensional model of a boiling water reactor (BWR) with simple adiabatic feedback is also included. TDTORT is verified through several transient one-dimensional, two-dimensional, and three-dimensional benchmark problems. The results show that the transport methodology and corresponding code developed in this work have sufficient accuracy and speed for computing the dynamic behavior of complex multidimensional neutronic systems

TEMPEST: A three-dimensional time-dependent computer program for hydrothermal analysis: Volume 1, Numerical methods and input instructions

International Nuclear Information System (INIS)

Trent, D.S.; Eyler, L.L.; Budden, M.J.

1983-09-01

This document describes the numerical methods, current capabilities, and the use of the TEMPEST (Version L, MOD 2) computer program. TEMPEST is a transient, three-dimensional, hydrothermal computer program that is designed to analyze a broad range of coupled fluid dynamic and heat transfer systems of particular interest to the Fast Breeder Reactor thermal-hydraulic design community. The full three-dimensional, time-dependent equations of motion, continuity, and heat transport are solved for either laminar or turbulent fluid flow, including heat diffusion and generation in both solid and liquid materials. 10 refs., 22 figs., 2 tabs

Three dimensional transport model for toroidal plasmas

International Nuclear Information System (INIS)

Copenhauer, C.

1980-12-01

A nonlinear MHD model, developed for three-dimensional toroidal geometries (asymmetric) and for high β (β approximately epsilon), is used as a basis for a three-dimensional transport model. Since inertia terms are needed in describing evolving magnetic islands, the model can calculate transport, both in the transient phase before nonlinear saturation of magnetic islands and afterwards on the resistive time scale. In the β approximately epsilon ordering, the plasma does not have sufficient energy to compress the parallel magnetic field, which allows the Alfven wave to be eliminated in the reduced nonlinear equations, and the model then follows the slower time scales. The resulting perpendicular and parallel plasma drift velocities can be identified with those of guiding center theory

Real-time three-dimensional ultrasound-assisted axillary plexus block defines soft tissue planes.

Science.gov (United States)

Clendenen, Steven R; Riutort, Kevin; Ladlie, Beth L; Robards, Christopher; Franco, Carlo D; Greengrass, Roy A

2009-04-01

Two-dimensional (2D) ultrasound is commonly used for regional block of the axillary brachial plexus. In this technical case report, we described a real-time three-dimensional (3D) ultrasound-guided axillary block. The difference between 2D and 3D ultrasound is similar to the difference between plain radiograph and computer tomography. Unlike 2D ultrasound that captures a planar image, 3D ultrasound technology acquires a 3D volume of information that enables multiple planes of view by manipulating the image without movement of the ultrasound probe. Observation of the brachial plexus in cross-section demonstrated distinct linear hyperechoic tissue structures (loose connective tissue) that initially inhibited the flow of the local anesthesia. After completion of the injection, we were able to visualize the influence of arterial pulsation on the spread of the local anesthesia. Possible advantages of this novel technology over current 2D methods are wider image volume and the capability to manipulate the planes of the image without moving the probe.

Towards a Three-Dimensional Near-Real Time Cloud Product for Aviation Safety and Weather Diagnoses

Science.gov (United States)

Minnis, Patrick; Nguyen, Louis; Palikonda, Rabindra; Spangeberg, Douglas; Nordeen, Michele L.; Yi, Yu-Hong; Ayers, J. Kirk

2004-01-01

Satellite data have long been used for determining the extent of cloud cover and for estimating the properties at the cloud tops. The derived properties can also be used to estimate aircraft icing potential to improve the safety of air traffic in the region. Currently, cloud properties and icing potential are derived in near-real time over the United States of America (USA) from the Geostationary Operational Environmental Satellite GOES) imagers at 75 W and 135 W. Traditionally, the results have been given in two dimensions because of the lack of knowledge about the vertical extent of clouds and the occurrence of overlapping clouds. Aircraft fly in a three-dimensional space and require vertical as well as horizontal information about clouds, their intensity, and their potential for icing. To improve the vertical component of the derived cloud and icing parameters, this paper explores various methods and datasets for filling in the three-dimensional space over the USA with cloud water.

Evaluation of left ventricular volumes in patients with congenital heart disease and abnormal left ventricular geometry. Comparison of MRI and transthoracic 3-dimensional echocardiography

International Nuclear Information System (INIS)

Gutberlet, M.; Grothoff, M.; Roettgen, R.; Lange, P.; Felix, R.; Abdul-Khaliq, H.; Schroeter, J.; Schmitt, B.; Vogel, M.

2003-01-01

Purpose: To assess the new method of 3-dimensional echocardiography in comparison to the 'gold standard' MRI as to its ability to calculate left ventricular volumes in patients with congenital heart disease. Materials and methods: Eighteen patients between the ages of 3.9 to 37.3 years (mean: 12.8±9.7) with a geometrically abnormal left ventricle were examined using a 1.5 T scanner with a fast gradient-echo sequence (TR=14 ms, TE=2.6-2.9 ms, FOV=300-400 mm, flip angle=20 , matrix=128:256, slice thickness=5 mm, retrospective gating) in multislice-multiphase technique. Transthoracic 3D-echocardiography was performed with a 3.5 MHz transducer and a Tomtec trademark (Munich, Germany) system for 3D reconstruction. Results: Volume calculation was possible in all patients with 3D-echocardiography, but the muscle mass calculation only succeeded in 11 to 18 patients (61%) due to inadequate visualization of the entire myocardium. Comparing MRI and 3D-echocardiography, the correlation was r=0.97 for the end-systolic volumes, r=0.98 for the end-diastolic volumes, r=0.79 for the end-systolic muscle mass and r=0.77 for the end-diastolic muscle mass. The agreement between both methods was considered good for the calculated end-diastolic volumes and sufficient for the calculated end-systolic volumes. The muscle mass calculations showed larger differences especially for the end-systolic mass. Mean intraobserver variability was 18.6% for end-systolic and 8.3% for end-diastolic volumes. Conclusion: In patients with an abnormal left ventricular configuration due to congenital heart disease, the new method of 3D-echocardiography is sufficient for volume calculations in preselected patients. The high intraobserver variability is still a limitation of transthoracic 3D-echocardiography in comparison to MRI. (orig.) [de

Strongly nonexponential time-resolved fluorescence of quantum-dot ensembles in three-dimensional photonic crystals

DEFF Research Database (Denmark)

Nikolaev, Ivan S.; Lodahl, Peter; van Driel, A. Floris

2007-01-01

We observe experimentally that ensembles of quantum dots in three-dimensional 3D photonic crystals reveal strongly nonexponential time-resolved emission. These complex emission decay curves are analyzed with a continuous distribution of decay rates. The log-normal distribution describes the decays...... parameter. This interpretation qualitatively agrees with the calculations of the 3D projected local density of states. We therefore conclude that fluorescence decay of ensembles of quantum dots is highly nonexponential to an extent that is controlled by photonic crystals....

Three dimensional canonical transformations

International Nuclear Information System (INIS)

Tegmen, A.

2010-01-01

A generic construction of canonical transformations is given in three-dimensional phase spaces on which Nambu bracket is imposed. First, the canonical transformations are defined as based on cannonade transformations. Second, it is shown that determination of the generating functions and the transformation itself for given generating function is possible by solving correspondent Pfaffian differential equations. Generating functions of type are introduced and all of them are listed. Infinitesimal canonical transformations are also discussed as the complementary subject. Finally, it is shown that decomposition of canonical transformations is also possible in three-dimensional phase spaces as in the usual two-dimensional ones.

Method for coupling two-dimensional to three-dimensional discrete ordinates calculations

International Nuclear Information System (INIS)

Thompson, J.L.; Emmett, M.B.; Rhoades, W.A.; Dodds, H.L. Jr.

1985-01-01

A three-dimensional (3-D) discrete ordinates transport code, TORT, has been developed at the Oak Ridge National Laboratory for radiation penetration studies. It is not feasible to solve some 3-D penetration problems with TORT, such as a building located a large distance from a point source, because (a) the discretized 3-D problem is simply too big to fit on the computer or (b) the computing time (and corresponding cost) is prohibitive. Fortunately, such problems can be solved with a hybrid approach by coupling a two-dimensional (2-D) description of the point source, which is assumed to be azimuthally symmetric, to a 3-D description of the building, the region of interest. The purpose of this paper is to describe this hybrid methodology along with its implementation and evaluation in the DOTTOR (Discrete Ordinates to Three-dimensional Oak Ridge Transport) code

Three-dimensional dose-response models of risk for radiation injury carcinogenesis

International Nuclear Information System (INIS)

Raabe, O.G.

1988-01-01

The use of computer graphics in conjunction with three-dimensional models of dose-response relationships for chronic exposure to ionizing radiation dramaticly clarifies the separate and interactive roles of competing risks. The three dimensions are average dose rate, exposure time, and risk. As an example, the functionally injurious and carcinogenic responses after systemic uptake of Ra-226 by beagles, mice and people with consequent alpha particle irradiation of the bone are represented by three-dimensional dose-rate/time/response surfaces that demonstrate the contributions with the passage of time of the competing deleterious responses. These relationships are further evaluated by mathematical stripping with three-dimensional illustrations that graphically show the resultant separate contribution of each effect. Radiation bone injury predominates at high dose rates and bone cancer at intermediate dose rates. Low dose rates result in spontaneous deaths from natural aging, yielding a type of practical threshold for bone cancer induction. Risk assessment is benefited by the insights that become apparent with these three-dimensional models. The improved conceptualization afforded by them contributes to planning and evaluating epidemiological analyses and experimental studies

Transhiatal and transthoracic resection in adenocarcinoma of the esophagus: Does the operative approach have an influence on the long-term prognosis?

Directory of Open Access Journals (Sweden)

Kneist Werner

2005-06-01

Full Text Available Abstract Background The goal of the present analysis was to investigate the long-term prognosis for adenocarcinoma of the esophagus treated with either the transhiatal (TH or the transthoracic (TT operative approach. Methods Between September 1985 and March 2004, esophageal resection due to carcinoma was performed on a total of 424 patients. This manuscript takes into account the 150 patients suffering from adenocarcinoma of the esophagus in whom a transhiatal resection of the esophagus was performed. In the event of transmural tumor growth and a justifiable risk of surgery, the transthoracic resection was selected. An extended mediastinal lymph node dissection, however, was only carried out in the course of the transthoracic approach. Results The transthoracic resection of the esophagus demonstrated a higher rate of general complications (p = 0.011 as well as a higher mortality rate (p = 0.011. The mediastinal dissection of the lymph nodes, however, revealed no prognostic influence. Considering all of the 150 patients with adenocarcinoma, as well as only those patients who had undergone curative resections (R0, the transhiatal approach was seen to demonstrate a better five-year survival rate of 32.1% versus 35.1%, with a median survival time of 24 versus 28 months, as compared with those who had undergone a transthoracic approach with a five-year survival rate of 13.6% (all patients versus 17.7% (R0 resection with a median survival time of 16 versus 17 months (p Conclusion The prognosis in patients with adenocarcinoma of the esophagus is influenced by the depth of the tumor (pT and the pM-category, as shown in the multivariate analysis. The present analysis did not demonstrate a relevant difference in survival for patients with N0 and N1 stages undergoing transhiatal or transthoracic esophagectomy. It is questionable, if a more extensive mediastinal lymph node dissection, in addition to the clearance of abdominal lymph nodes, offers prognostic

Three-dimensional transesophageal echocardiography: Principles and clinical applications

Directory of Open Access Journals (Sweden)

Annette Vegas

2016-01-01

Full Text Available A basic understanding of evolving 3D technology enables the echocardiographer to master the new skills necessary to acquire, manipulate, and interpret 3D datasets. Single button activation of specific 3D imaging modes for both TEE and transthoracic echocardiography (TTE matrix array probes include (a live, (b zoom, (c full volume (FV, and (d color Doppler FV. Evaluation of regional LV wall motion by RT 3D TEE is based on a change in LV chamber subvolume over time from altered segmental myocardial contractility. Unlike standard 2D TEE, there is no direct measurement of myocardial thickening or displacement of individual segments.

Use of real-time three-dimensional transesophageal echocardiography in type A aortic dissections: Advantages of 3D TEE illustrated in three cases

Directory of Open Access Journals (Sweden)

Cindy J Wang

2015-01-01

Full Text Available Stanford type A aortic dissections often present to the hospital requiring emergent surgical intervention. Initial diagnosis is usually made by computed tomography; however transesophageal echocardiography (TEE can further characterize aortic dissections with specific advantages: It may be performed on an unstable patient, it can be used intra-operatively, and it has the ability to provide continuous real-time information. Three-dimensional (3D TEE has become more accessible over recent years allowing it to serve as an additional tool in the operating room. We present a case series of three patients presenting with type A aortic dissections and the advantages of intra-operative 3D TEE to diagnose the extent of dissection in each case. Prior case reports have demonstrated the use of 3D TEE in type A aortic dissections to characterize the extent of dissection and involvement of neighboring structures. In our three cases described, 3D TEE provided additional understanding of spatial relationships between the dissection flap and neighboring structures such as the aortic valve and coronary orifices that were not fully appreciated with two-dimensional TEE, which affected surgical decisions in the operating room. This case series demonstrates the utility and benefit of real-time 3D TEE during intra-operative management of a type A aortic dissection.

Three-dimensional simulations of Bingham plastic flows with the multiple-relaxation-time lattice Boltzmann model

OpenAIRE

Song-Gui Chen; Chuan-Hu Zhang; Yun-Tian Feng; Qi-Cheng Sun; Feng Jin

2016-01-01

This paper presents a three-dimensional (3D) parallel multiple-relaxation-time lattice Boltzmann model (MRT-LBM) for Bingham plastics which overcomes numerical instabilities in the simulation of non-Newtonian fluids for the Bhatnagar–Gross–Krook (BGK) model. The MRT-LBM and several related mathematical models are briefly described. Papanastasiou’s modified model is incorporated for better numerical stability. The impact of the relaxation parameters of the model is studied in detail. The MRT-L...

Time-efficient, high-resolution, whole brain three-dimensional macromolecular proton fraction mapping.

Science.gov (United States)

Yarnykh, Vasily L

2016-05-01

Macromolecular proton fraction (MPF) mapping is a quantitative MRI method that reconstructs parametric maps of a relative amount of macromolecular protons causing the magnetization transfer (MT) effect and provides a biomarker of myelination in neural tissues. This study aimed to develop a high-resolution whole brain MPF mapping technique using a minimal number of source images for scan time reduction. The described technique was based on replacement of an actually acquired reference image without MT saturation by a synthetic one reconstructed from R1 and proton density maps, thus requiring only three source images. This approach enabled whole brain three-dimensional MPF mapping with isotropic 1.25 × 1.25 × 1.25 mm(3) voxel size and a scan time of 20 min. The synthetic reference method was validated against standard MPF mapping with acquired reference images based on data from eight healthy subjects. Mean MPF values in segmented white and gray matter appeared in close agreement with no significant bias and small within-subject coefficients of variation (maps demonstrated sharp white-gray matter contrast and clear visualization of anatomical details, including gray matter structures with high iron content. The proposed synthetic reference method improves resolution of MPF mapping and combines accurate MPF measurements with unique neuroanatomical contrast features. © 2015 Wiley Periodicals, Inc.

Experimental Demonstration of OCDMA Transmission Using a Three-Dimensional (Time-Wavelength-Polarization) Codeset

Science.gov (United States)

McGeehan, John E.; Motaghian Nezam, S. M. R.; Saghari, P.; Willner, Alan E.; Omrani, Reza; Vijay Kumar, P.

2005-10-01

We experimentally demonstrate a three-dimensional (3-D) optical code-division multiple-access (OCDMA) transmission system that encodes data on time, wavelength, and polarization. Such a system may be ideal for use in short-distance optical local area networks (LANs), where polarization states remain fairly stable. This type of coding can increase the number of potential users, by a factor of approximately 2kappa, over a conventional two-dimensional (2-D) code given the same code constraints, where"kappa"is the number of collisions the codeset will allow. We encode 1-Gbit/s, 11-Gchip/s data with an 11-chip, 4-wavelength, weight-4 (per polarization) code using free-space and fiber delay lines and polarization beam combiners and decode using a polarization beam splitter, wavelength demultiplexers, and additional fiber/free-space delays. After threshold detection using independent detectors for each polarization state, we obtain 1-Gbit/s nonreturn to zero (NRZ) output data. Encoding, transmission decoding, and detection carry a penalty of 1.8 dB.

Dynamic time-dependent analysis and static three-dimensional imaging procedures for computer-assisted CNS studies

International Nuclear Information System (INIS)

Budinger, T.F.; DeLand, F.H.; Duggan, H.E.; Bouz, J.J.; Hoop, B. Jr.; McLaughlin, W.T.; Weber, P.M.

1975-01-01

Two-dimensional computer image-processing techniques have not proved to be of importance in diagnostic nuclear medicine primarily because the radionuclide distribution represents a three-dimensional problem. More recent developments in three-dimensional reconstruction from multiple views or multiple detectors promise to overcome the major limitations in previous work with digital computers. These techniques are now in clinical use for static imaging; however, speed limitations have prevented application to dynamic imaging. The future development of these methods will require innovations in patient positioning and multiple-view devices for either single-gamma or positron annihilation detection

Utility of three-dimensional method for diagnosing meniscal lesions

International Nuclear Information System (INIS)

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

1998-01-01

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

Real-time visual tracking of less textured three-dimensional objects on mobile platforms

Science.gov (United States)

Seo, Byung-Kuk; Park, Jungsik; Park, Hanhoon; Park, Jong-Il

2012-12-01

Natural feature-based approaches are still challenging for mobile applications (e.g., mobile augmented reality), because they are feasible only in limited environments such as highly textured and planar scenes/objects, and they need powerful mobile hardware for fast and reliable tracking. In many cases where conventional approaches are not effective, three-dimensional (3-D) knowledge of target scenes would be beneficial. We present a well-established framework for real-time visual tracking of less textured 3-D objects on mobile platforms. Our framework is based on model-based tracking that efficiently exploits partially known 3-D scene knowledge such as object models and a background's distinctive geometric or photometric knowledge. Moreover, we elaborate on implementation in order to make it suitable for real-time vision processing on mobile hardware. The performance of the framework is tested and evaluated on recent commercially available smartphones, and its feasibility is shown by real-time demonstrations.

Three dimensional visualization of medical images

International Nuclear Information System (INIS)

Suto, Yasuzo

1992-01-01

Three dimensional visualization is a stereoscopic technique that allows the diagnosis and treatment of complicated anatomy site of the bone and organ. In this article, the current status and technical application of three dimensional visualization are introduced with special reference to X-ray CT and MRI. The surface display technique is the most common for three dimensional visualization, consisting of geometric model, voxel element, and stereographic composition techniques. Recent attention has been paid to display method of the content of the subject called as volume rendering, whereby information on the living body is provided accurately. The application of three dimensional visualization is described in terms of diagnostic imaging and surgical simulation. (N.K.)

Three-dimensional P velocity structure in Beijing area

Science.gov (United States)

Yu, Xiang-Wei; Chen, Yun-Tai; Wang, Pei-De

2003-01-01

A detail three-dimensional P wave velocity structure of Beijing, Tianjin and Tangshan area (BTT area) was determined by inverting local earthquake data. In total 16 048 P wave first arrival times from 16048 shallow and mid-depth crustal earthquakes, which occurred in and around the BTT area from 1992 to 1999 were used. The first arrival times are recorded by Northern China United Telemetry Seismic Network and Yanqing-Huailai Digital Seismic Network. Hypocentral parameters of 1 132 earthquakes with magnitude M L=1.7 6.2 and the three-dimensional P wave velocity structure were obtained simultaneously. The inversion result reveals the complicated lateral heterogeneity of P wave velocity structure around BTT area. The tomographic images obtained are also found to explain other seismological observations well.

Three-dimensional stellarator equilibrium as an ohmic steady state

International Nuclear Information System (INIS)

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

1985-07-01

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

Study of fission dynamics with the three-dimensional Langevin equations

Energy Technology Data Exchange (ETDEWEB)

Eslamizadeh, H. [Persian Gulf University, Department of Physics, Bushehr (Iran, Islamic Republic of)

2011-11-15

The dynamics of fission has been studied by solving one- and three-dimensional Langevin equations with dissipation generated through the chaos weighted wall and window friction formula. The average prescission neutron multiplicities, fission probabilities and the mean fission times have been calculated in a broad range of the excitation energy for compound nuclei {sup 210}Po and {sup 224}Th formed in the fusion-fission reactions {sup 4}He+{sup 206}Pb, {sup 16}O+{sup 208}Pb and results compared with the experimental data. The analysis of the results shows that the average prescission neutron multiplicities, fission probabilities and the mean fission times calculated by one- and three-dimensional Langevin equations are different from each other, and also the results obtained based on three-dimensional Langevin equations are in better agreement with the experimental data. (orig.)

Real-time in situ three-dimensional integral videography and surgical navigation using augmented reality: a pilot study

Science.gov (United States)

Suenaga, Hideyuki; Hoang Tran, Huy; Liao, Hongen; Masamune, Ken; Dohi, Takeyoshi; Hoshi, Kazuto; Mori, Yoshiyuki; Takato, Tsuyoshi

2013-01-01

To evaluate the feasibility and accuracy of a three-dimensional augmented reality system incorporating integral videography for imaging oral and maxillofacial regions, based on preoperative computed tomography data. Three-dimensional surface models of the jawbones, based on the computed tomography data, were used to create the integral videography images of a subject's maxillofacial area. The three-dimensional augmented reality system (integral videography display, computed tomography, a position tracker and a computer) was used to generate a three-dimensional overlay that was projected on the surgical site via a half-silvered mirror. Thereafter, a feasibility study was performed on a volunteer. The accuracy of this system was verified on a solid model while simulating bone resection. Positional registration was attained by identifying and tracking the patient/surgical instrument's position. Thus, integral videography images of jawbones, teeth and the surgical tool were superimposed in the correct position. Stereoscopic images viewed from various angles were accurately displayed. Change in the viewing angle did not negatively affect the surgeon's ability to simultaneously observe the three-dimensional images and the patient, without special glasses. The difference in three-dimensional position of each measuring point on the solid model and augmented reality navigation was almost negligible (augmented reality system was highly accurate and effective for surgical navigation and for overlaying a three-dimensional computed tomography image on a patient's surgical area, enabling the surgeon to understand the positional relationship between the preoperative image and the actual surgical site, with the naked eye. PMID:23703710

Teaching veterinary obstetrics using three-dimensional animation technology.

Science.gov (United States)

Scherzer, Jakob; Buchanan, M Flint; Moore, James N; White, Susan L

2010-01-01

In this three-year study, test scores for students taught veterinary obstetrics in a classroom setting with either traditional media (photographs, text, and two-dimensional graphical presentations) were compared with those for students taught by incorporating three-dimensional (3D) media (linear animations and interactive QuickTime Virtual Reality models) into the classroom lectures. Incorporation of the 3D animations and interactive models significantly increased students' scores on essay questions designed to assess their comprehension of the subject matter. This approach to education may help to better prepare students for dealing with obstetrical cases during their final clinical year and after graduation.

Transthoracic Doppler echocardiography – noninvasive diagnostic window for coronary flow reserve assessment

Directory of Open Access Journals (Sweden)

Dimitrow Paweł

2003-04-01

Full Text Available Abstract This review focuses on transthoracic Doppler echocardiography as noninvasive method used to assess coronary flow reserve (CFR in a wide spectrum of clinical settings. Transthoracic Doppler echocardiography is rapidly gaining appreciation as popular tool to measure CFR both in stenosed and normal epicardial coronary arteries (predominantly in left anterior descending coronary artery. Post-stenotic CFR measurement is helpful in: functional assessment of moderate stenosis, detection of significant or critical stenosis, monitoring of restenosis after revascularization. In the absence of stenosis in the epicardial coronary artery, decreased CFR enable to detect impaired microvascular vasodilatation in: reperfused myocardial infarct, arterial hypertension with or without left ventricular hypertrophy, diabetes mellitus, hypercholesterolemia, syndrome X, hypertrophic cardiomyopathy. In these diseases, noninvasive transthoracic Doppler echocardiography allows for serial CFR evaluations to explore the effect of various pharmacological therapies.

Three-dimensional versus two-dimensional vision in laparoscopy

DEFF Research Database (Denmark)

Sørensen, Stine D; Savran, Mona Meral; Konge, Lars

2016-01-01

were cohort size and characteristics, skill trained or operation performed, instrument used, outcome measures, and conclusions. Two independent authors performed the search and data extraction. RESULTS: Three hundred and forty articles were screened for eligibility, and 31 RCTs were included...... through a two-dimensional (2D) projection on a monitor, which results in loss of depth perception. To counter this problem, 3D imaging for laparoscopy was developed. A systematic review of the literature was performed to assess the effect of 3D laparoscopy. METHODS: A systematic search of the literature...... in the review. Three trials were carried out in a clinical setting, and 28 trials used a simulated setting. Time was used as an outcome measure in all of the trials, and number of errors was used in 19 out of 31 trials. Twenty-two out of 31 trials (71 %) showed a reduction in performance time, and 12 out of 19...

Real-time Risk Assessment for Aids to Navigation Using Fuzzy-FSA on Three-Dimensional Simulation System

Directory of Open Access Journals (Sweden)

Jinbiao Chen

2014-06-01

Full Text Available The risk level of the Aids to Navigation (AtoNs can reflect the ship navigation safety level in the channel to some extent. In order to appreciate the risk level of the aids to navigation (AtoNs in a navigation channel and to provide some decision-making suggestions for the AtoNs Maintenance and Management Department, the risk assessment index system of the AtoNs was built considering the advanced experience of IALA. Under the Formal Safety Assessment frame, taking the advantages of the fuzzy comprehensive evaluation method, the fuzzy-FSA model of risk assessment for aids to navigation was established. The model was implemented for the assessment of aids to navigation in Shanghai area based on the aids to navigation three-dimensional simulation system. The real-time data were extracted from the existing information system of aids to navigation, and the real-time risk assessment for aids to navigation of the chosen channel was performed on platform of the three-dimensional simulation system, with the risk assessment software. Specifically, the deep-water channel of the Yangtze River estuary was taken as an example to illustrate the general assessment procedure. The method proposed presents practical significance and application prospect on the maintenance and management of the aids to navigation.

Self-consistent theory of three-dimensional convection in the geomagnetic tail

International Nuclear Information System (INIS)

Birn, J.; Schindler, K.

1983-01-01

The self-consistent theory of time-dependent convection in the earth's magnetotail of Schindler and Birn (1982) is extended to three dimensions to include more realistic tail geometry and three-dimensional flow. We confirm that a steady state solution implies unrealistic tail geometry or large particle or energy losses that are unrealistic during quiet times and conclude therefore that as in the 2-dimensional case the magnetotail becomes time-dependent for typical convection electric fields. Explicit solutions are derived, even analytically, for the three-dimensional flow and the electric and magnetic field in a realistic tail geometry, and quantitative examples are presented. Consequences of time-dependent convection are demonstrated considering two idealized cases of magnetosphere response to solar wind changes: (1) uniform compression as the likely consequence of increasing (static, dynamic or magnetic) solar wind pressure; and (2) compression only in the z direction perpendicular to the plasma sheet as the probable consequence of a dawn to dusk external electric field (E/sub y/>0), corresponding to a southward interplanetary magnetic field component (B/sub z/ 0 with geomagnetic activity. Several other features, already present in the 2-dimensional theory, are confirmed

MDCT-Guided Transthoracic Needle Aspiration Biopsy of the Lung Using the Transscapular Approach

International Nuclear Information System (INIS)

Rossi, Umberto G.; Seitun, Sara; Ferro, Carlo

2011-01-01

The purpose of this study is to report our preliminary experience using MDCT-guided percutaneous transthoracic needle aspiration biopsy using the transscapular approach in the upper posterolateral lung nodules, an area that it is difficult or hazardous to reach with the conventional approach. Five patients underwent CT-guided percutaneous transthoracic needle aspiration biopsy of the lung via the transscapular approach. A coaxial needle technique was used in all patients. Biopsy was successful in all patients. No major complications were encountered. One patient developed a minimal pneumothorax next to the lesion immediately after biopsy, which resolved spontaneously. MDCT-guided percutaneous transthoracic needle aspiration biopsy of the lung via the transscapular approach is an effective and safe procedure that reduces the risk of pneumothorax in selected patients.

Two- and three-dimensional evaluation of the acetabulum in the pediatric patient

International Nuclear Information System (INIS)

Magid, D.; Fishman, E.K.; Sponseller, P.D.

1987-01-01

Complex anatomic structures such as the hip and acetabulum are best evaluated with the use of two- and three-dimensional reconstruction techniques and standard transaxial CT data. CT scans of children with various hip pathologies, including congenital hip dislocation, slipped capital femoral epiphyses, hip dysplasias, dwarfism, and acetabular fractures, were reviewed to determine the value of two- and three-dimensional imaging. The advantages of two-dimensional imaging techniques (sequential coronal/sagittal reconstruction) and three-dimensional valumetric imaging techniques (using real-time video display) are illustrated with specific examples

Three-dimensional C-arm CT-guided transjugular intrahepatic portosystemic shunt placement: Feasibility, technical success and procedural time

Energy Technology Data Exchange (ETDEWEB)

Ketelsen, Dominik; Groezinger, Gerd; Maurer, Michael; Grosse, Ulrich; Horger, Marius; Nikolaou, Konstantin; Syha, Roland [University of Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Lauer, Ulrich M. [University of Tuebingen, Internal Medicine I, Department of Gastroenterology, Hepatology and Infectious disease, Tuebingen (Germany)

2016-12-15

Establishment of transjugular intrahepatic portosystemic shunts (TIPS) constitutes a standard procedure in patients suffering from portal hypertension. The most difficult step in TIPS placement is blind puncture of the portal vein. This study aimed to evaluate three-dimensional mapping of portal vein branches and targeted puncture of the portal vein. Twelve consecutive patients suffering from refractory ascites by liver cirrhosis were included in this retrospective study to evaluate feasibility, technical success and procedural time of C-arm CT-targeted puncture of the portal vein. As a control, 22 patients receiving TIPS placement with fluoroscopy-guided blind puncture were included to compare procedural time. Technical success could be obtained in 100 % of the study group (targeted puncture) and in 95.5 % of the control group (blind puncture). Appropriate, three-dimensional C-arm CT-guided mapping of the portal vein branches could be achieved in all patients. The median number of punctures in the C-arm CT-guided study group was 2 ± 1.3 punctures. Procedural time was significantly lower in the study group (14.8 ± 8.2 min) compared to the control group (32.6 ± 22.7 min) (p = 0.02). C-arm CT-guided portal vein mapping is technically feasible and a promising tool for TIPS placement resulting in a significant reduction of procedural time. (orig.)

Three-Dimensional Navier-Stokes Calculations Using the Modified Space-Time CESE Method

Science.gov (United States)

Chang, Chau-lyan

2007-01-01

The space-time conservation element solution element (CESE) method is modified to address the robustness issues of high-aspect-ratio, viscous, near-wall meshes. In this new approach, the dependent variable gradients are evaluated using element edges and the corresponding neighboring solution elements while keeping the original flux integration procedure intact. As such, the excellent flux conservation property is retained and the new edge-based gradients evaluation significantly improves the robustness for high-aspect ratio meshes frequently encountered in three-dimensional, Navier-Stokes calculations. The order of accuracy of the proposed method is demonstrated for oblique acoustic wave propagation, shock-wave interaction, and hypersonic flows over a blunt body. The confirmed second-order convergence along with the enhanced robustness in handling hypersonic blunt body flow calculations makes the proposed approach a very competitive CFD framework for 3D Navier-Stokes simulations.

Three-dimensional volumetric display by inclined-plane scanning

Science.gov (United States)

Miyazaki, Daisuke; Eto, Takuma; Nishimura, Yasuhiro; Matsushita, Kenji

2003-05-01

A volumetric display system based on three-dimensional (3-D) scanning that uses an inclined two-dimensional (2-D) image is described. In the volumetric display system a 2-D display unit is placed obliquely in an imaging system into which a rotating mirror is inserted. When the mirror is rotated, the inclined 2-D image is moved laterally. A locus of the moving image can be observed by persistence of vision as a result of the high-speed rotation of the mirror. Inclined cross-sectional images of an object are displayed on the display unit in accordance with the position of the image plane to observe a 3-D image of the object by persistence of vision. Three-dimensional images formed by this display system satisfy all the criteria for stereoscopic vision. We constructed the volumetric display systems using a galvanometer mirror and a vector-scan display unit. In addition, we constructed a real-time 3-D measurement system based on a light section method. Measured 3-D images can be reconstructed in the 3-D display system in real time.

Three dimensional imaging in cardiac nuclear medicine

International Nuclear Information System (INIS)

Torizuka, Kanji; Ishii, Yasushi; Yonekura, Yoshiharu; Yamamoto, Kazutaka; Tamaki, Takeyoshi

1981-01-01

Methods to obtain three dimensional images of the heart were reviewed. Gated three dimensional display reconstructed from images using bidirectional collimator, was a useful method to detect akinesis of the heart wall. Tomographic observation of the heart can be carried out by a pinhole collimator to image ischemia with high sensitivity. However the focusing plane must be carefully selected to prevent false positives. In the case of emission CT (ECT), utilization of positron emitters gave a quantitative image without correction, whereas single photon ECT needed the correction due to the absorption of γ-ray. Though the reliability of the images by ECT was high, the time required for data acquisition was much longer than that by a 7 pinhole or bidirectional collimator. (Nakanishi, T.)

Quantum field between moving mirrors: A three dimensional example

Science.gov (United States)

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

1995-01-01

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

Prognostic value of real-time three-dimensional echocardiography compared to two-dimensional echocardiography in patients with systolic heart failure.

Science.gov (United States)

Mancuso, Frederico J N; Moises, Valdir A; Almeida, Dirceu R; Poyares, Dalva; Storti, Luciana J; Brito, Flavio S; Tufik, Sergio; de Paola, Angelo A V; Carvalho, Antonio C C; Campos, Orlando

2018-04-01

Heart failure (HF) is associated with morbidity and mortality. Real-time three-dimensional echocardiography (RT3DE) may offer additional prognostic data in patients with HF. The study aimed to evaluate the prognostic value of real-time three-dimensional echocardiography (RT3DE). This is a prospective study that included 89 patients with HF and left ventricular ejection fraction (LVEF) < 0.50 who were followed for 48 months. Left atrium and ventricular volumes and functions were evaluated by RT3DE. TDI and two-dimensional echocardiography parameters were also obtained. The endpoint was a composite of death, heart transplantation and hospitalization for acute decompensated HF. The mean age was 55 ± 11 years, and the LVEF was 0.32 ± 0.10. The composite endpoint occurred in 49 patients (18 deaths, 30 hospitalizations, one heart transplant). Patients with outcomes had greater left atrial volume (40 ± 16 vs. 32 ± 12 mL/m 2 ; p < 0.01) and right ventricle diameter (41 ± 9 vs. 37 ± 8 mm, p = 0.01), worse total emptying fraction of the left atrium (36 ± 13% vs. 41 ± 11%; p = 0.03), LVEF (0.30 ± 0.09 vs. 0.34 ± 0.11; p = 0.02), right ventricle fractional area change (34.8 ± 12.1% vs. 39.2 ± 11.3%; p = 0.04), and greater E/e' ratio (19 ± 9 vs. 16 ± 8; p = 0.04) and systolic pulmonary artery pressure (SPAP) (50 ± 15 vs. 36 ± 11 mmHg; p < 0.01). In multivariate analysis, LVEF (OR 4.6; CI 95% 1.2-17.6; p < 0.01) and SPAP (OR 12.5; CI 95% 1.8-86.9; p < 0.01) were independent predictors of patient outcomes. LVEF and the SPAP were independent predictors of outcomes in patients with HF.

Monitoring groundwater-surface water interaction using time-series and time-frequency analysis of transient three-dimensional electrical resistivity changes

Science.gov (United States)

Johnson, Timothy C.; Slater, Lee D.; Ntarlagiannis, Dimitris; Day-Lewis, Frederick D.; Elwaseif, Mehrez

2012-01-01

Time-lapse resistivity imaging is increasingly used to monitor hydrologic processes. Compared to conventional hydrologic measurements, surface time-lapse resistivity provides superior spatial coverage in two or three dimensions, potentially high-resolution information in time, and information in the absence of wells. However, interpretation of time-lapse electrical tomograms is complicated by the ever-increasing size and complexity of long-term, three-dimensional (3-D) time series conductivity data sets. Here we use 3-D surface time-lapse electrical imaging to monitor subsurface electrical conductivity variations associated with stage-driven groundwater-surface water interactions along a stretch of the Columbia River adjacent to the Hanford 300 near Richland, Washington, USA. We reduce the resulting 3-D conductivity time series using both time-series and time-frequency analyses to isolate a paleochannel causing enhanced groundwater-surface water interactions. Correlation analysis on the time-lapse imaging results concisely represents enhanced groundwater-surface water interactions within the paleochannel, and provides information concerning groundwater flow velocities. Time-frequency analysis using the Stockwell (S) transform provides additional information by identifying the stage periodicities driving groundwater-surface water interactions due to upstream dam operations, and identifying segments in time-frequency space when these interactions are most active. These results provide new insight into the distribution and timing of river water intrusion into the Hanford 300 Area, which has a governing influence on the behavior of a uranium plume left over from historical nuclear fuel processing operations.

Three-dimensional echocardiographic assessment of the repaired mitral valve.

Science.gov (United States)

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

2014-02-01

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

Study on three dimensional seismic isolation system

International Nuclear Information System (INIS)

Morishita, Masaki; Kitamura, Seiji

2003-01-01

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

Fast three-dimensional core optimization based on modified one-group model

Energy Technology Data Exchange (ETDEWEB)

Freire, Fernando S. [ELETROBRAS Termonuclear S.A. - ELETRONUCLEAR, Rio de Janeiro, RJ (Brazil). Dept. GCN-T], e-mail: freire@eletronuclear.gov.br; Martinez, Aquilino S.; Silva, Fernando C. da [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear], e-mail: aquilino@con.ufrj.br, e-mail: fernando@con.ufrj.br

2009-07-01

The optimization of any nuclear reactor core is an extremely complex process that consumes a large amount of computer time. Fortunately, the nuclear designer can rely on a variety of methodologies able to approximate the analysis of each available core loading pattern. Two-dimensional codes are usually used to analyze the loading scheme. However, when particular axial effects are present in the core, two-dimensional analysis cannot produce good results and three-dimensional analysis can be required at all time. Basically, in this paper are presented the major advantages that can be found when one use the modified one-group diffusion theory coupled with a buckling correction model in optimization process. The results of the proposed model are very accurate when compared to benchmark results obtained from detailed calculations using three-dimensional nodal codes (author)

Fast three-dimensional core optimization based on modified one-group model

International Nuclear Information System (INIS)

Freire, Fernando S.; Martinez, Aquilino S.; Silva, Fernando C. da

2009-01-01

The optimization of any nuclear reactor core is an extremely complex process that consumes a large amount of computer time. Fortunately, the nuclear designer can rely on a variety of methodologies able to approximate the analysis of each available core loading pattern. Two-dimensional codes are usually used to analyze the loading scheme. However, when particular axial effects are present in the core, two-dimensional analysis cannot produce good results and three-dimensional analysis can be required at all time. Basically, in this paper are presented the major advantages that can be found when one use the modified one-group diffusion theory coupled with a buckling correction model in optimization process. The results of the proposed model are very accurate when compared to benchmark results obtained from detailed calculations using three-dimensional nodal codes (author)

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

DEFF Research Database (Denmark)

Cereser, Alberto; Strobl, Markus; Hall, Stephen A.

2017-01-01

constituting the material. This article presents a new non-destructive 3D technique to study centimeter-sized bulk samples with a spatial resolution of hundred micrometers: time-of-flight three-dimensional neutron diffraction (ToF 3DND). Compared to existing analogous X-ray diffraction techniques, ToF 3DND......-of-flight neutron beamline. The technique was developed and tested with data collected at the Materials and Life Science Experimental Facility of the Japan Proton Accelerator Complex (J-PARC) for an iron sample. We successfully reconstructed the shape of 108 grains and developed an indexing procedure...

Prognostic value of three-dimensional ultrasound for fetal hydronephrosis

Science.gov (United States)

WANG, JUNMEI; YING, WEIWEN; TANG, DAXING; YANG, LIMING; LIU, DONGSHENG; LIU, YUANHUI; PAN, JIAOE; XIE, XING

2015-01-01

The present study evaluated the prognostic value of three-dimensional ultrasound for fetal hydronephrosis. Pregnant females with fetal hydronephrosis were enrolled and a novel three-dimensional ultrasound indicator, renal parenchymal volume/kidney volume, was introduced to predict the postnatal prognosis of fetal hydronephrosis in comparison with commonly used ultrasound indicators. All ultrasound indicators of fetal hydronephrosis could predict whether postnatal surgery was required for fetal hydronephrosis; however, the predictive performance of renal parenchymal volume/kidney volume measurements as an individual indicator was the highest. In conclusion, ultrasound is important in predicting whether postnatal surgery is required for fetal hydronephrosis, and the three-dimensional ultrasound indicator renal parenchymal volume/kidney volume has a high predictive performance. Furthermore, the majority of cases of fetal hydronephrosis spontaneously regress subsequent to birth, and the regression time is closely associated with ultrasound indicators. PMID:25667626

Three-dimensional particle image velocimetry measurement technique

International Nuclear Information System (INIS)

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

2004-01-01

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

Semi-implicit method for three-dimensional compressible MHD simulation

International Nuclear Information System (INIS)

Harned, D.S.; Kerner, W.

1984-03-01

A semi-implicit method for solving the full compressible MHD equations in three dimensions is presented. The method is unconditionally stable with respect to the fast compressional modes. The time step is instead limited by the slower shear Alfven motion. The computing time required for one time step is essentially the same as for explicit methods. Linear stability limits are derived and verified by three-dimensional tests on linear waves in slab geometry. (orig.)

Structures of two-dimensional three-body systems

International Nuclear Information System (INIS)

Ruan, W.Y.; Liu, Y.Y.; Bao, C.G.

1996-01-01

Features of the structure of L = 0 states of a two-dimensional three-body model system have been investigated. Three types of permutation symmetry of the spatial part, namely symmetric, antisymmetric, and mixed, have been considered. A comparison has been made between the two-dimensional system and the corresponding three-dimensional one. The effect of symmetry on microscopic structures is emphasized. (author)

Time-resolved broadband analysis of slow-light propagation and superluminal transmission of electromagnetic waves in three-dimensional photonic crystals

NARCIS (Netherlands)

Gómez Rivas, J.; Farré Benet, A.; Niehusmann, J.; Haring Bolivar, P.; Kurz, H.

2005-01-01

A time-resolved analysis of the amplitude and phase of THz pulses propagating through three-dimensional photonic crystals is presented. Single-cycle pulses of THz radiation allow measurements over a wide frequency range, spanning more than an octave below, at and above the bandgap of strongly

Elastocapillary fabrication of three-dimensional microstructures

NARCIS (Netherlands)

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

2010-01-01

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

Three-dimensional imaging of hidden objects using positron emission backscatter

International Nuclear Information System (INIS)

Lee, Dongwon; Cowee, Misa; Fenimore, Ed; Galassi, Mark; Looker, Quinn; Mcneil, Wendy V.; Stonehill, Laura; Wallace, Mark

2009-01-01

Positron emission backscatter imaging is a technique for interrogation and three-dimensional (3-D) reconstruction of hidden objects when we only have access to the objects from one side. Using time-of-flight differences in detected direct and backscattered positron-emitted photons, we construct 3-D images of target objects. Recently at Los Alamos National Laboratory, a fully three-dimensional imaging system has been built and the experimental results are discussed in this paper. Quantitative analysis of images reconstructed in both two- and three-dimensions are also presented.

Birkhoff's theorem for three-dimensional AdS gravity

International Nuclear Information System (INIS)

Ayon-Beato, Eloy; Martinez, Cristian; Zanelli, Jorge

2004-01-01

All three-dimensional matter-free space-times with negative cosmological constant, compatible with cyclic symmetry, are identified. The only cyclic solutions are the 2+1 (BTZ) black hole with SO(2)xR isometry, and the self-dual Coussaert-Henneaux space-times, with isometry groups SO(2)xSO(2,1) or SO(2)xSO(2)

Transthoracic ultrasound in the assessment of pleural and pulmonary diseases: use and limitations.

Science.gov (United States)

Sperandeo, Marco; Rotondo, Antonio; Guglielmi, Giuseppe; Catalano, Daniela; Feragalli, Beatrice; Trovato, Guglielmo M

2014-10-01

Interest in transthoracic ultrasound (US) procedures increased after the availability of portable US equipment suitable for use at the patient's bedside. It is possible to detect space-occupying lesions of the pleura, pleural effusion, focal or diffuse pleural thickening and subpleural lesions of the lung, even in emergency settings. Transthoracic US is useful as a guidance system for thoracentesis and peripheral lesion biopsy, where it minimises the occurrence of pneumothorax and haemorrhage. Transthoracic US imaging is strongly influenced by physical interaction of the ultrasonic beam at the tissue/air interface, which gives rise to reverberations classified as simple (A-line), "comet tail" and "ring down"(B-line) artifacts. Although these artifacts can be suggestive of a disease condition, they are essentially imaging errors present even in normal subjects and in empty-pleura post-pneumonectomy patients. In order to clarify some confusion and to report on the state of the art, we present a review of the literature on transthoracic US in diseases of the pleura and peripheral lung regions and our own clinical experience over 3 decades. The review focuses on quality assurance procedures and their value in diagnostic imaging and patient monitoring and warns against possible inappropriate indications and misleading information. Thoracic US is much more than "fishing for the moon in the well".

Three-dimensional MR imaging of the cerebrospinal system with the RARE technique

International Nuclear Information System (INIS)

Hennig, J.; Ott, D.; Ylayasski, J.

1987-01-01

Three-dimensional RARE myelography is a fast technique for high-resolution imaging of the cerebrospinal fluid. A data set with 1 x 1 x 1-mm resolution can be generated with a 12-minute acquisition time. Sophisticated three-dimensional display algorithms allow reconstruction of planes at arbitrary angles and full three-dimensional displays, which yield extremely useful information for neurosurgical planning. Additionally, the injection of contrast agent can be simulated on the computer and communication pathways between structures of interest can be found noninvasively

Three-dimensional printing and pediatric liver disease.

Science.gov (United States)

Alkhouri, Naim; Zein, Nizar N

2016-10-01

Enthusiastic physicians and medical researchers are investigating the role of three-dimensional printing in medicine. The purpose of the current review is to provide a concise summary of the role of three-dimensional printing technology as it relates to the field of pediatric hepatology and liver transplantation. Our group and others have recently demonstrated the feasibility of printing three-dimensional livers with identical anatomical and geometrical landmarks to the native liver to facilitate presurgical planning of complex liver surgeries. Medical educators are exploring the use of three-dimensional printed organs in anatomy classes and surgical residencies. Moreover, mini-livers are being developed by regenerative medicine scientist as a way to test new drugs and, eventually, whole livers will be grown in the laboratory to replace organs with end-stage disease solving the organ shortage problem. From presurgical planning to medical education to ultimately the bioprinting of whole organs for transplantation, three-dimensional printing will change medicine as we know in the next few years.

CT-Guided Transthoracic Core Biopsy for Pulmonary Tuberculosis: Diagnostic Value of the Histopathological Findings in the Specimen

International Nuclear Information System (INIS)

Fukuda, Hozumi; Ibukuro, Kenji; Tsukiyama, Toshitaka; Ishii, Rei

2004-01-01

We evaluated the value of CT-guided transthoracic core biopsy for the diagnosis of mycobacterial pulmonary nodules. The 30 subjects in this study had pulmonary nodules that had been either diagnosed histopathologically as tuberculosis or were suspected as tuberculosis based on a specimen obtained by CT-guided transthoracic core biopsy. The histopathological findings, the existence of acid-fast bacilli in the biopsy specimens, and the clinical course of the patients after the biopsy were reviewed retrospectively. Two of the three histological findings for tuberculosis that included epithelioid cells, multinucleated giant cells and caseous necrosis were observed in 21 of the nodules which were therefore diagnosed as histological tuberculosis. Six of these 21 nodules were positive for acid-fast bacilli, confirming the diagnosis of tuberculosis. Thirteen of the 21 nodules did not contain acid-fast bacilli but decreased in size in response to antituberculous treatment and were therefore diagnosed as clinical tuberculosis. Seven nodules with only caseous necrosis were diagnosed as suspected tuberculosis, with a final diagnosis of tuberculosis being made in 4 of the nodules and a diagnosis of old tuberculosis in 2 nodules. Two nodules with only multinucleated giant cells were diagnosed as suspected tuberculosis with 1 of these nodules being diagnosed finally as tuberculosis and the other nodule as a nonspecific granuloma. When any two of the three following histopathological findings - epithelioid cells, multinucleated giant cells or caseous necrosis - are observed in a specimen obtained by CT-guided transthoracic core biopsy, the diagnosis of tuberculosis can be established without the detection of acid-fast bacilli or Mycobacterium tuberculosis

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

OpenAIRE

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

2013-01-01

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

Three-dimensional reconstruction of functional brain images

International Nuclear Information System (INIS)

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

1999-01-01

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

Three-dimensional reconstruction of functional brain images

Energy Technology Data Exchange (ETDEWEB)

Inoue, Masato; Shoji, Kazuhiko; Kojima, Hisayoshi; Hirano, Shigeru; Naito, Yasushi; Honjo, Iwao [Kyoto Univ. (Japan)

1999-08-01

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

Analytical real-time measurement of a three-dimensional weld pool surface

International Nuclear Information System (INIS)

Zhang, WeiJie; Zhang, YuMing; Wang, XueWu

2013-01-01

The ability to observe and measure weld pool surfaces in real-time is the core of the foundation for next generation intelligent welding that can partially imitate skilled welders who observe the weld pool to acquire information on the welding process. This study aims at the real-time measurement of the specular three-dimensional (3D) weld pool surface under a strong arc in gas tungsten arc welding (GTAW). An innovative vision system is utilized in this study to project a dot-matrix laser pattern on the specular weld pool surface. Its reflection from the surface is intercepted at a distance from the arc by a diffuse plane. The intercepted laser dots illuminate this plane producing an image showing the reflection pattern. The deformation of this reflection pattern from the projected pattern (e.g. the dot matrix) is used to derive the 3D shape of the reflection surface, i.e., the weld pool surface. Based on careful analysis, the underlying reconstruction problem is formulated mathematically. An analytic solution is proposed to solve this formulated problem resulting in the weld pool surface being reconstructed on average in 3.04 ms during welding experiments. A vision-based monitoring system is thus established to measure the weld pool surface in GTAW in real-time. In order to verify the effectiveness of the proposed reconstruction algorithm, first numerical simulation is conducted. The proposed algorithm is then tested on a spherical convex mirror with a priori knowledge of its geometry. The detailed analysis of the measurement error validates the accuracy of the proposed algorithm. Results from the real-time experiments verify the robustness of the proposed reconstruction algorithm. (paper)

Obstructed bi-leaflet prosthetic mitral valve imaging with real-time three-dimensional transesophageal echocardiography.

Science.gov (United States)

Shimbo, Mai; Watanabe, Hiroyuki; Kimura, Shunsuke; Terada, Mai; Iino, Takako; Iino, Kenji; Ito, Hiroshi

2015-01-01

Real-time three-dimensional transesophageal echocardiography (RT3D-TEE) can provide unique visualization and better understanding of the relationship among cardiac structures. Here, we report the case of an 85-year-old woman with an obstructed mitral prosthetic valve diagnosed promptly by RT3D-TEE, which clearly showed a leaflet stuck in the closed position. The opening and closing angles of the valve leaflets measured by RT3D-TEE were compatible with those measured by fluoroscopy. Moreover, RT3D-TEE revealed, in the ring of the prosthetic valve, thrombi that were not visible on fluoroscopy. RT3D-TEE might be a valuable diagnostic technique for prosthetic mitral valve thrombosis. © 2014 Wiley Periodicals, Inc.

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

Application of Simulated Three Dimensional CT Image in Orthognathic Surgery

International Nuclear Information System (INIS)

Kim, Hyun Don; Park, Chang Seo; Yoo, Sun Kook; Lee, Kyoung Sang

1998-01-01

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

Three-dimensional organization of the human interphase nucleus

NARCIS (Netherlands)

T.A. Knoch (Tobias); C. Münkel (Christian); W. Waldeck (Waldemar); J. Langowski (Jörg)

2000-01-01

textabstractDespite the successful linear sequencing of the human genome its three-dimensional structure is widely unknown, although it is important for gene regulation and replication. For a long time the interphase nucleus has been viewed as a 'spaghetti soup' of DNA without much internal

Painful percutaneous transthoracic needle biopsy of Schwannoma: a case report

International Nuclear Information System (INIS)

Kim, Sung Hoon; Chun, Kyung Ah; Kim, Young Joo; Park, Seog Hee; Shin, Kyung Sub; Lee, Eun Jung

1995-01-01

Percutaneous aspiration needle biopsy of the intrathoracic disease is a safe, easy, and accurate diagnostic method. It usually causes mild pain or discomfort during the procedure. We had a patient who complained of severe sharp pain, well localized at the biopsy site of the target mass during CT-guided transthoracic aspiration biopsy. It was pathologically confirmed as an intrathoracic schwannoma after special staining. To our knowledge, there has been no published report of such a painful percutaneous needle biopsy in a patient with schwannoma in Korea. Two cases were reported in other radiologic journals. The severe sharp pain developed during the transthoracic aspiration needle biopsy is a reliable sign of neurogenic tumor, therefore the participating radiologist should recommend specific immumochemical stain for neurogenic tumor to pathologist

Three-dimensional low-energy topological invariants

International Nuclear Information System (INIS)

Bakalarska, M.; Broda, B.

2000-01-01

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

Solution of the time-dependent, three-dimensional resistive magnetohydrodynamic equations

International Nuclear Information System (INIS)

Finan, C.H. III; Killeen, J.; California Univ., Davis

1981-01-01

Resistive magnetohydrodynamics (MHD) is described by a set of eight coupled, nonlinear, three-dimensional, time-dependent, partial differential equations. A computer code, IMP (Implicit MHD Program), has been developed to solve these equations numerically by the method of finite differences on an Eulerian mesh. In this model, the equations are expressed in orthogonal curvilinear coordinates, making the code applicable to a variety of coordinate systems. The Douglas-Gunn algorithm for Alternating-Direction Implicit (ADI) temporal advancement is used to avoid the limitations in timestep size imposed by explicit methods. The equations are expressed as conservation laws, the momentum and energy equations are nonconservative. This is to: (1) provide enhanced numerical stability by eliminating errors introduced by the nonvanishing of nabla x B on the finite difference mesh; and, (2) allow the simulation of low β plasmas. The resulting finite difference equations are a coupled system of nonlinear algebraic equations which are solved by the Newton-Raphson iteration technique. We apply our model to a number of problems of importance in magnetic fusion research. Ideal and resistive internal kink instabilities are simulated in a Cartesian geometry. Growth rates and nonlinear saturation amplitudes are found to be in agreement with previous analytic and numerical predictions. We also simulate these instabilities in a torus, which demonstrates the versatility of the orthogonal curvilinear coordinate representation. (orig.)

Application of Time-Frequency Domain Transform to Three-Dimensional Interpolation of Medical Images.

Science.gov (United States)

Lv, Shengqing; Chen, Yimin; Li, Zeyu; Lu, Jiahui; Gao, Mingke; Lu, Rongrong

2017-11-01

Medical image three-dimensional (3D) interpolation is an important means to improve the image effect in 3D reconstruction. In image processing, the time-frequency domain transform is an efficient method. In this article, several time-frequency domain transform methods are applied and compared in 3D interpolation. And a Sobel edge detection and 3D matching interpolation method based on wavelet transform is proposed. We combine wavelet transform, traditional matching interpolation methods, and Sobel edge detection together in our algorithm. What is more, the characteristics of wavelet transform and Sobel operator are used. They deal with the sub-images of wavelet decomposition separately. Sobel edge detection 3D matching interpolation method is used in low-frequency sub-images under the circumstances of ensuring high frequency undistorted. Through wavelet reconstruction, it can get the target interpolation image. In this article, we make 3D interpolation of the real computed tomography (CT) images. Compared with other interpolation methods, our proposed method is verified to be effective and superior.

Foundations of the theory of three-dimensional quadrupolar mass spectrometry. 1

International Nuclear Information System (INIS)

Sheretov, Eh.P.

1979-01-01

The basic principles of the theory of three-dimensional quadrupolar mass spectrometry are developed. It is shown that the ''stretching'' of the electrode system of the sensor of a three-dimensional quadrupolar mass spectrometer in the direction of an axis (introduction of the system assymetry) leads to a sharp decrease of the high-frequency field effect on the particle trajectory in this direction. Presented are ratios determining the configuration of electrode systems of sensors of flight-type quadrupolar mass spectrometers. Specific features of the stability diagram for such analyzers are discussed. It is shown that the property detected makes it possible to develop new promising time-of-flight three-dimensional quadrupolar mass spectrometers

[Bone drilling simulation by three-dimensional imaging].

Science.gov (United States)

Suto, Y; Furuhata, K; Kojima, T; Kurokawa, T; Kobayashi, M

1989-06-01

The three-dimensional display technique has a wide range of medical applications. Pre-operative planning is one typical application: in orthopedic surgery, three-dimensional image processing has been used very successfully. We have employed this technique in pre-operative planning for orthopedic surgery, and have developed a simulation system for bone-drilling. Positive results were obtained by pre-operative rehearsal; when a region of interest is indicated by means of a mouse on the three-dimensional image displayed on the CRT, the corresponding region appears on the slice image which is displayed simultaneously. Consequently, the status of the bone-drilling is constantly monitored. In developing this system, we have placed emphasis on the quality of the reconstructed three-dimensional images, on fast processing, and on the easy operation of the surgical planning simulation.

Risk factors influencing the pleural drainage volume after transthoracic oesophagectomy.

Science.gov (United States)

Kosugi, Shin-ichi; Kanda, Tatsuo; Yajima, Kazuhito; Ishikawa, Takashi; Sakamoto, Kaoru

2013-06-01

The objective of this study was to clarify the factors influencing pleural drainage volume after transthoracic oesophagectomy and to determine criteria for the selection of patients who would benefit from the early removal of chest drains. Clinicopathological characteristics of 155 patients who underwent transthoracic oesophagectomy were prospectively collected, and the daily drainage volume of each patient was retrospectively reviewed. Potential risk factors were compared between the high-output group (n = 39) and low-output group (n = 116), which were dichotomized using the 75th percentile of total pleural drainage volume of the total study population. Multivariate logistic regression analyses were used to identify independent risk factors. The median duration of drainage was 10 days, with a median total drainage volume of 2258 ml. Of 27 potential risk factors influencing the drainage volume, creatinine clearance (P = 0.04), operative approach (P = 0.03) and thoracic duct removal (P = 0.01) were significantly associated with the total pleural drainage volume. The removal of the thoracic duct (P = 0.02; odds ratio, 4.02; 95% confidence interval 1.20-13.41) and lower creatinine clearance (P = 0.04; odds ratio, 1.02; 95% confidence interval 1.00-1.04) was independent risk factors for increased pleural drainage volume after transthoracic oesophagectomy. The early removal of chest drains may be possible in patients without these risk factors.

Three-dimensional simulation of vortex breakdown

Science.gov (United States)

Kuruvila, G.; Salas, M. D.

1990-01-01

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

[Advances in the research of application of hydrogels in three-dimensional bioprinting].

Science.gov (United States)

Yang, J; Zhao, Y; Li, H H; Zhu, S H

2016-08-20

Hydrogels are three-dimensional networks made of hydrophilic polymer crosslinked through covalent bonds or physical intermolecular attractions, which can contain growth media and growth factors to support cell growth. In bioprinting, hydrogels are used to provide accurate control over cellular microenvironment and to dramatically reduce experimental repetition times, meanwhile we can obtain three-dimensional cell images of high quality. Hydrogels in three-dimensional bioprinting have received a considerable interest due to their structural similarities to the natural extracellular matrix and polyporous frameworks which can support the cellular proliferation and survival. Meanwhile, they are accompanied by many challenges.

Three-Dimensional Printing Surgical Applications.

Science.gov (United States)

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

2015-01-01

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

Three-dimensional dose-response models of competing risks and natural life span

International Nuclear Information System (INIS)

Raabe, O.G.

1987-01-01

Three-dimensional dose-rate/time/response surfaces for chronic exposure to carcinogens, toxicants, and ionizing radiation dramatically clarify the separate and interactive roles of competing risks. The three dimensions are average dose rate, exposure time, and risk. An illustration with computer graphics shows the contributions with the passage of time of the competing risks of death from radiation pneumonitis/fibrosis, lung cancer, and natural aging consequent to the inhalation of plutonium-239 dioxide by beagles. These relationships are further evaluated by mathematical stripping with three-dimensional illustrations that graphically show the resultant separate contribution of each fatal effect. Radiation pneumonitis predominates at high dose rates and lung cancer at intermediate dose rates. Low dose rates result in spontaneous deaths from natural aging, yielding a type of practical threshold for lung cancer induction. Risk assessment is benefited by the insights that become apparent with these three-dimensional models. The improved conceptualization afforded by them contributes to the planning and evaluation of epidemiological analyses and experimental studies involving chronic exposure to toxicants

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.

Towards three-dimensional optical metamaterials

Science.gov (United States)

Tanaka, Takuo; Ishikawa, Atsushi

2017-12-01

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

Three-dimensional imaging modalities in endodontics

Science.gov (United States)

Mao, Teresa

2014-01-01

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

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

International Nuclear Information System (INIS)

Mao, Teresa; Neelakantan, Prasanna

2014-01-01

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

A three-dimensional field solutions of Halbach

International Nuclear Information System (INIS)

Chen Jizhong; Xiao Jijun; Zhang Yiming; Xu Chunyan

2008-01-01

A three-dimensional field solutions are presented for Halback cylinder magnet. Based on Ampere equivalent current methods, the permanent magnets are taken as distributing of current density. For getting the three-dimensional field solution of ideal polarized permanent magnets, the solution method entails the use of the vector potential and involves the closed-form integration of the free-space Green's function. The programmed field solution are ideal for performing rapid parametric studies of the dipole Halback cylinder magnets made from rare earth materials. The field solutions are verified by both an analytical two-dimensional algorithm and three-dimensional finite element software. A rapid method is presented for extensive analyzing and optimizing Halbach cylinder magnet. (authors)

Topological phases in a three-dimensional topological insulator with a time-reversal invariant external field

International Nuclear Information System (INIS)

Guo, Xiaoyong; Ren, Xiaobin; Wang, Gangzhi; Peng, Jie

2014-01-01

We investigate the impact of a time-reversal invariant external field on the topological phases of a three-dimensional (3D) topological insulator. By taking the momentum k z as a parameter, we calculate the spin-Chern number analytically. It is shown that both the quantum spin Hall phase and the integer quantum Hall phase can be realized in our system. When the strength of the external field is varied, a series of topological phase transitions occurs with the closing of the energy gap or the spin-spectrum gap. In a tight-binding form, the surface modes are discussed numerically to confirm the analytically results. (paper)

Three Dimensional Dirac Semimetals

Science.gov (United States)

Zaheer, Saad

2014-03-01

Dirac points on the Fermi surface of two dimensional graphene are responsible for its unique electronic behavior. One can ask whether any three dimensional materials support similar pseudorelativistic physics in their bulk electronic spectra. This possibility has been investigated theoretically and is now supported by two successful experimental demonstrations reported during the last year. In this talk, I will summarize the various ways in which Dirac semimetals can be realized in three dimensions with primary focus on a specific theory developed on the basis of representations of crystal spacegroups. A three dimensional Dirac (Weyl) semimetal can appear in the presence (absence) of inversion symmetry by tuning parameters to the phase boundary separating a bulk insulating and a topological insulating phase. More generally, we find that specific rules governing crystal symmetry representations of electrons with spin lead to robust Dirac points at high symmetry points in the Brillouin zone. Combining these rules with microscopic considerations identifies six candidate Dirac semimetals. Another method towards engineering Dirac semimetals involves combining crystal symmetry and band inversion. Several candidate materials have been proposed utilizing this mechanism and one of the candidates has been successfully demonstrated as a Dirac semimetal in two independent experiments. Work carried out in collaboration with: Julia A. Steinberg, Steve M. Young, J.C.Y. Teo, C.L. Kane, E.J. Mele and Andrew M. Rappe.

Feasibility and Safety of a Transthoracic Pneumostoma Airway Bypass in Severe Emphysema Patients.

Science.gov (United States)

Snell, Gregory I; Holsworth, Lynda; Khorramnia, Sadie; Westall, Glen P; Williams, Trevor J; Marasco, Silvana; Gooi, Julian H

2017-01-01

Emphysema is characterised by airflow obstruction, hyperinflation, and resultant dyspnoea. It is worth investigating whether decompression improves lung mechanics and enhances quality of life (QoL). The purpose of this study was to describe the feasibility and safety of creating a transthoracic pneumostoma to enable lung reduction. A transthoracic 10-mm diameter Portaero Access Tube (Portaero™, Cupertino, CA, USA) was implanted via a third intercostal space incision in 15 severe emphysema patients [mean age 63 years, forced expiratory volume in 1 s 54% predicted, diffusing capacity for carbon monoxide 31% predicted, residual volume 246% predicted, Six-Minute Walk Test 296 m]. Four weeks later, an 8-mm Portaero Disposable Tube (3-8 cm in length) was substituted and changed daily thereafter. The targeted primary endpoints were a ≥12% increase in forced expiratory volume in 1 s and a decrease of ≥4 points in Saint George's Respiratory Questionnaire score at 6 months. Sixteen procedures were performed on 15 patients, complicated by 1 intercostal haemorrhage, 1 pneumothorax, and universal mild surgical emphysema. Early patency issues were common, but often responded to external endoscopic debridement or argon plasma laser. Three-month patency was achieved in 9 of 15 patients, and 6 of these had long-term patency (mean of 4 years). Patency was associated with potentially useful long-term improvements or stability in spirometry, residual volume, and QoL. However, the primary endpoints were not met at 6 months. The creation and maintenance of a transthoracic pneumostoma appears feasible and safe in patients with severe emphysema. Further studies refining patient selection (perhaps via chest computed tomography collateral ventilation and fissure assessments), techniques, and tube materials are suggested. © 2017 S. Karger AG, Basel.

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.

Multiparallel Three-Dimensional Optical Microscopy

Science.gov (United States)

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

2010-01-01

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

Backlund transformations and three-dimensional lattice equations

NARCIS (Netherlands)

Nijhoff, F.W.; Capel, H.W.; Wiersma, G.L.; Quispel, G.R.W.

1984-01-01

A (nonlocal) linear integral equation is studied, which allows for Bäcklund transformations in the measure. The compatibility of three of these transformations leads to an integrable nonlinear three-dimensional lattice equation. In appropriate continuum limits the two-dimensional Toda-lattice

Arching in three-dimensional clogging

Science.gov (United States)

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

2017-06-01

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

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

International Nuclear Information System (INIS)

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

1995-01-01

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

Multi-GPU accelerated three-dimensional FDTD method for electromagnetic simulation.

Science.gov (United States)

Nagaoka, Tomoaki; Watanabe, Soichi

2011-01-01

Numerical simulation with a numerical human model using the finite-difference time domain (FDTD) method has recently been performed in a number of fields in biomedical engineering. To improve the method's calculation speed and realize large-scale computing with the numerical human model, we adapt three-dimensional FDTD code to a multi-GPU environment using Compute Unified Device Architecture (CUDA). In this study, we used NVIDIA Tesla C2070 as GPGPU boards. The performance of multi-GPU is evaluated in comparison with that of a single GPU and vector supercomputer. The calculation speed with four GPUs was approximately 3.5 times faster than with a single GPU, and was slightly (approx. 1.3 times) slower than with the supercomputer. Calculation speed of the three-dimensional FDTD method using GPUs can significantly improve with an expanding number of GPUs.

Intraoperative device closure of perimembranous ventricular septal defects in the young children under transthoracic echocardiographic guidance; initial experience

Directory of Open Access Journals (Sweden)

Cao Hua

2011-12-01

Full Text Available Abstract Objectives This study aimed to assess the safety and feasibility of intraoperative device closure of perimembranous ventricular septal defects (VSD in young children guided by transthoracic echocardiography (TTE. Methods We enrolled 18 patients from our hospital to participate in the study from June 2011 to September 2011. A minimal inferior median incision was performed after full evaluation of the perimembranous VSD by real-time TTE, and a domestically made device was inserted to occlude the perimembranous VSD. The proper size of the device was determined by means of transthoracic echocardiographic analysis. Results Implantation was ultimately successful in 16 patients using TTE guidance. In these cases, the complete closure rate immediately following the operation and on subsequent follow-up was 100%. Symmetric devices were used in 14 patients, and asymmetric devices were used in two patients. Two patient were transformed to surgical treatment, one for significant residual shunting, and the other for unsuccessful wire penetration of the VSD. The follow-up periods were less than nine months, and only one patient had mild aortic regurgitation. There were no instances of residual shunt, noticeable aortic regurgitation, significant arrhythmia, thrombosis, or device failure. Conclusions Minimally invasive transthoracic device closure of perimembranous VSDs is safe and feasible, using a domestically made device under transthoracic echocardiographic guidance, without the need for cardiopulmonary bypass. This technique should be considered an acceptable alternative to surgery or device closure guided by transesophageal echocardiography in selected young children. However, a long-term evaluation of outcomes is necessary.

The current status of the three-dimensional ultrasonography in gyneaecology

Energy Technology Data Exchange (ETDEWEB)

Ong, Chiou Li [Dept. of Diagnostic and Interventional Imaging, KK Women' s and Children' s Hospital, Singapore (Singapore)

2016-01-15

Ultrasonography (US) is the most recent cross-sectional imaging modality to acquire three-dimensional (3D) capabilities. The reconstruction of volumetric US data for multiplanar display took a significantly longer time to develop in comparison with computed tomography and magnetic resonance imaging. The current equipment for 3D-US is capable of producing high-resolution images in three different planes, including real-time surface-rendered images. The use of 3D-US in gynaecology was accelerated through the development of the endovaginal volume transducer, which allows the automated acquisition of volumetric US data. Although initially considered an adjunct to two-dimensional US, 3D-US is now the imaging modality of choice for the assessment of Müllerian duct anomalies and the location of intrauterine devices.

Teaching three-dimensional surgical concepts of inguinal hernia in a time-effective manner using a two-dimensional paper-cut.

Science.gov (United States)

Mann, B D; Seidman, A; Haley, T; Sachdeva, A K

1997-06-01

Because inguinal hernia repair is difficult for third-year students to comprehend, a 2-dimensional paper-cut was developed to teach the concepts of inguinal hernia in a time-effective manner before students' observation of herniorrhaphy in the operating room. Using Adobe Illustrator 5.5 for MacIntosh, a 2-dimensional inexpensively printed paper-cut was created to allow students to perform their own simulated hernia repair before observing surgery. The exercise was performed using a no.15 scalpel or an iris scissors and was evaluated by comparing 10-question pre-tests and post-tests. Seventy-five students performed the exercise, most completing it within 15 minutes. The mean pre-test score was 7.4/10 and the mean post-test score was 9.1/10. Students performing the paper-cut reported better understanding when observing actual herniorrhaphy. A 2-dimensional paper-cut ("surgical origami") may be a time-effective method to prepare students for the observation of hernia repair.

Comparison of two three-dimensional cephalometric analysis computer software.

Science.gov (United States)

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

2014-10-01

Three-dimensional cephalometric analyses are getting more attraction in orthodontics. The aim of this study was to compare two softwares to evaluate three-dimensional cephalometric analyses of orthodontic treatment outcomes. Twenty cone beam computed tomography images were obtained using i-CAT(®) imaging system from patient's records as part of their regular orthodontic records. The images were analyzed using InVivoDental5.0 (Anatomage Inc.) and 3DCeph™ (University of Illinois at Chicago, Chicago, IL, USA) software. Before and after orthodontic treatments data were analyzed using t-test. Reliability test using interclass correlation coefficient was stronger for InVivoDental5.0 (0.83-0.98) compared with 3DCeph™ (0.51-0.90). Paired t-test comparison of the two softwares shows no statistical significant difference in the measurements made in the two softwares. InVivoDental5.0 measurements are more reproducible and user friendly when compared to 3DCeph™. No statistical difference between the two softwares in linear or angular measurements. 3DCeph™ is more time-consuming in performing three-dimensional analysis compared with InVivoDental5.0.

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.)

Three-dimensional appearance of the lips muscles with three-dimensional isotropic MRI: in vivo study.

Science.gov (United States)

Olszewski, Raphael; Liu, Y; Duprez, T; Xu, T M; Reychler, H

2009-06-01

Our knowledge of facial muscles is based primarily on atlases and cadaveric studies. This study describes a non-invasive in vivo method (3D MRI) for segmenting and reconstructing facial muscles in a three-dimensional fashion. Three-dimensional (3D), T1-weighted, 3 Tesla, isotropic MRI was applied to a subject. One observer performed semi-automatic segmentation using the Editor module from the 3D Slicer software (Harvard Medical School, Boston, MA, USA), version 3.2. We were able to successfully outline and three-dimensionally reconstruct the following facial muscles: pars labialis orbicularis oris, m. levatro labii superioris alaeque nasi, m. levator labii superioris, m. zygomaticus major and minor, m. depressor anguli oris, m. depressor labii inferioris, m. mentalis, m. buccinator, and m. orbicularis oculi. 3D reconstruction of the lip muscles should be taken into consideration in order to improve the accuracy and individualization of existing 3D facial soft tissue models. More studies are needed to further develop efficient methods for segmentation in this field.

Real-time three-dimensional speckle tracking echocardiography: technical aspects and clinical applications

Directory of Open Access Journals (Sweden)

Sorrentino R

2016-11-01

Full Text Available Regina Sorrentino, Roberta Esposito, Enrica Pezzullo, Maurizio Galderisi Department of Advanced Biomedical Sciences, Interdepartmental Laboratory of Cardiac Imaging, Federico II University Hospital, Naples, Italy Abstract: Three-dimensional speckle tracking echocardiography (3D STE is a novel technique for the quantification of cardiac deformation based on tracking of ultrasonic speckles in gray scale full-volume 3D images. Developments in ultrasound technologies have made 3D speckle tracking widely available. Two-dimensional echocardiography has intrinsic limitations regarding estimation of left ventricular (LV volumes, ejection fraction, and LV mechanics, due to its inherent foreshortening errors and dependency on geometric models. The development of 3D echocardiography has improved reproducibility and accuracy. Data regarding the feasibility, accuracy, and clinical applications of 3D STE are rapidly assembling. From the tracking results, 3D STE derives several parameters, including longitudinal, circumferential and radial strain, as well as a combined assessment of longitudinal and circumferential strain, termed area strain. 3D STE can also quantify LV rotational movements such as rotation, twist, and torsion. 3D STE provides a better insight on global and regional myocardial deformation. Main applications include detection of subclinical myocardial involvement in heart failure, arterial hypertension, dyssynchrony, and ischemic heart disease. Emerging areas of application include a large spectrum of heart-involving systemic conditions, such as prediction of rejection in heart transplant patients, early detection of cardiotoxicity in patients receiving chemotherapy for cancer, and deeper physiological understanding of LV contraction mechanics in different types of athletes. Aim of this review is to discuss background, technical acquisition and processing aspects as well as recognized and developing clinical applications of this emerging

The use of virtual reality to reimagine two-dimensional representations of three-dimensional spaces

Science.gov (United States)

Fath, Elaine

2015-03-01

A familiar realm in the world of two-dimensional art is the craft of taking a flat canvas and creating, through color, size, and perspective, the illusion of a three-dimensional space. Using well-explored tricks of logic and sight, impossible landscapes such as those by surrealists de Chirico or Salvador Dalí seem to be windows into new and incredible spaces which appear to be simultaneously feasible and utterly nonsensical. As real-time 3D imaging becomes increasingly prevalent as an artistic medium, this process takes on an additional layer of depth: no longer is two-dimensional space restricted to strategies of light, color, line and geometry to create the impression of a three-dimensional space. A digital interactive environment is a space laid out in three dimensions, allowing the user to explore impossible environments in a way that feels very real. In this project, surrealist two-dimensional art was researched and reimagined: what would stepping into a de Chirico or a Magritte look and feel like, if the depth and distance created by light and geometry were not simply single-perspective illusions, but fully formed and explorable spaces? 3D environment-building software is allowing us to step into these impossible spaces in ways that 2D representations leave us yearning for. This art project explores what we gain--and what gets left behind--when these impossible spaces become doors, rather than windows. Using sketching, Maya 3D rendering software, and the Unity Engine, surrealist art was reimagined as a fully navigable real-time digital environment. The surrealist movement and its key artists were researched for their use of color, geometry, texture, and space and how these elements contributed to their work as a whole, which often conveys feelings of unexpectedness or uneasiness. The end goal was to preserve these feelings while allowing the viewer to actively engage with the space.

High-resolution three-dimensional mapping of semiconductor dopant potentials

DEFF Research Database (Denmark)

Twitchett, AC; Yates, TJV; Newcomb, SB

2007-01-01

Semiconductor device structures are becoming increasingly three-dimensional at the nanometer scale. A key issue that must be addressed to enable future device development is the three-dimensional mapping of dopant distributions, ideally under "working conditions". Here we demonstrate how a combin......Semiconductor device structures are becoming increasingly three-dimensional at the nanometer scale. A key issue that must be addressed to enable future device development is the three-dimensional mapping of dopant distributions, ideally under "working conditions". Here we demonstrate how...... a combination of electron holography and electron tomography can be used to determine quantitatively the three-dimensional electrostatic potential in an electrically biased semiconductor device with nanometer spatial resolution....

Ultrasonography-guided Transthoracic Cutting Biopsy of Pulmonary Lesion: Diagnostic Benefits and Safety

Energy Technology Data Exchange (ETDEWEB)

Yang, Mei Ah; Park, Mi Hyun [Dankook University Hospital, Cheonan (Korea, Republic of); Shin, Byung Seok [Chungnam National University Hospital, Daejeon (Korea, Republic of); Ohm, Joon Young [Bucheon St. Mary' s Hospital, Bucheon (Korea, Republic of)

2012-06-15

To assess the safety and usefulness of ultrasonography-guided transthoracic cutting biopsy for lung lesions. Eighty-eight patients (66 men, 22 women, mean age 59 years) with lung lesions underwent an ultrasonography(USG)-guided transthoracic cutting biopsy. The final diagnosis was based on the findings of surgery and clinical and radiological follow-ups. The histopathologic results and diagnostic accuracy of cutting biopsy were determined. Also, the complication rate was statistically evaluated according to the mass size, number of biopsies, and the presence or absence of pleural effusion. Biopsy specimens were successfully obtained in all patients. 79 of 88 lesions (89.8%) were established by histopathology. The final diagnosis was malignant in 58 and benign in 28. The remaining 2 patients were lost to follow-up. Diagnostic sensitivity for malignant lesions was 89.6% (52/58) and that for benign lesions was 96.4% (27/28). Procedure-related complications occurred in 9 patients (10.2%) including pneumothorax (n = 2) and hemoptysis (n = 7). And there was no significant difference according to mass size, number of biopsies, or presence of pleural effusion. USG-guided transthoracic cutting biopsy is a useful and safe method for technically-feasible lung lesions

Ultrasonography-guided Transthoracic Cutting Biopsy of Pulmonary Lesion: Diagnostic Benefits and Safety

International Nuclear Information System (INIS)

Yang, Mei Ah; Park, Mi Hyun; Shin, Byung Seok; Ohm, Joon Young

2012-01-01

To assess the safety and usefulness of ultrasonography-guided transthoracic cutting biopsy for lung lesions. Eighty-eight patients (66 men, 22 women, mean age 59 years) with lung lesions underwent an ultrasonography(USG)-guided transthoracic cutting biopsy. The final diagnosis was based on the findings of surgery and clinical and radiological follow-ups. The histopathologic results and diagnostic accuracy of cutting biopsy were determined. Also, the complication rate was statistically evaluated according to the mass size, number of biopsies, and the presence or absence of pleural effusion. Biopsy specimens were successfully obtained in all patients. 79 of 88 lesions (89.8%) were established by histopathology. The final diagnosis was malignant in 58 and benign in 28. The remaining 2 patients were lost to follow-up. Diagnostic sensitivity for malignant lesions was 89.6% (52/58) and that for benign lesions was 96.4% (27/28). Procedure-related complications occurred in 9 patients (10.2%) including pneumothorax (n = 2) and hemoptysis (n = 7). And there was no significant difference according to mass size, number of biopsies, or presence of pleural effusion. USG-guided transthoracic cutting biopsy is a useful and safe method for technically-feasible lung lesions

Equilibrium: three-dimensional configurations

International Nuclear Information System (INIS)

Anon.

1987-01-01

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

Alternating-direction implicit numerical solution of the time-dependent, three-dimensional, single fluid, resistive magnetohydrodynamic equations

Energy Technology Data Exchange (ETDEWEB)

Finan, C.H. III

1980-12-01

Resistive magnetohydrodynamics (MHD) is described by a set of eight coupled, nonlinear, three-dimensional, time-dependent, partial differential equations. A computer code, IMP (Implicit MHD Program), has been developed to solve these equations numerically by the method of finite differences on an Eulerian mesh. In this model, the equations are expressed in orthogonal curvilinear coordinates, making the code applicable to a variety of coordinate systems. The Douglas-Gunn algorithm for Alternating-Direction Implicit (ADI) temporal advancement is used to avoid the limitations in timestep size imposed by explicit methods. The equations are solved simultaneously to avoid syncronization errors.

Volume scanning three-dimensional display with an inclined two-dimensional display and a mirror scanner

Science.gov (United States)

Miyazaki, Daisuke; Kawanishi, Tsuyoshi; Nishimura, Yasuhiro; Matsushita, Kenji

2001-11-01

A new three-dimensional display system based on a volume-scanning method is demonstrated. To form a three-dimensional real image, an inclined two-dimensional image is rapidly moved with a mirror scanner while the cross-section patterns of a three-dimensional object are displayed sequentially. A vector-scan CRT display unit is used to obtain a high-resolution image. An optical scanning system is constructed with concave mirrors and a galvanometer mirror. It is confirmed that three-dimensional images, formed by the experimental system, satisfy all the criteria for human stereoscopic vision.

Three-dimensional FDTD simulation of biomaterial exposure to electromagnetic nanopulses

Energy Technology Data Exchange (ETDEWEB)

Simicevic, Neven [Center for Applied Physics Studies, Louisiana Tech University, PO Box 10348, Ruston, LA 71272 (United States)

2005-11-07

Ultra-wideband (UWB) electromagnetic pulses of nanosecond duration, or nanopulses, have recently been approved by the Federal Communications Commission for a number of different applications. They are also being explored for applications in biotechnology and medicine. The simulation of the propagation of a nanopulse through biological matter, previously performed using a two-dimensional finite-difference time-domain (FDTD) method, has been extended here into a full three-dimensional computation. To account for the UWB frequency range, the geometrical resolution of the exposed sample was 0.25 mm and the dielectric properties of biological matter were accurately described in terms of the Debye model. The results obtained from the three-dimensional computation support the previously obtained results: the electromagnetic field inside a biological tissue depends on the incident pulse rise time and width, with increased importance of the rise time as the conductivity increases; no thermal effects are possible for the low pulse repetition rates, supported by recent experiments. New results show that the dielectric sample exposed to nanopulses behaves as a dielectric resonator. For a sample in a cuvette, we obtained the dominant resonant frequency and the Q-factor of the resonator.

Three-dimensional FDTD simulation of biomaterial exposure to electromagnetic nanopulses

International Nuclear Information System (INIS)

Simicevic, Neven

2005-01-01

Ultra-wideband (UWB) electromagnetic pulses of nanosecond duration, or nanopulses, have recently been approved by the Federal Communications Commission for a number of different applications. They are also being explored for applications in biotechnology and medicine. The simulation of the propagation of a nanopulse through biological matter, previously performed using a two-dimensional finite-difference time-domain (FDTD) method, has been extended here into a full three-dimensional computation. To account for the UWB frequency range, the geometrical resolution of the exposed sample was 0.25 mm and the dielectric properties of biological matter were accurately described in terms of the Debye model. The results obtained from the three-dimensional computation support the previously obtained results: the electromagnetic field inside a biological tissue depends on the incident pulse rise time and width, with increased importance of the rise time as the conductivity increases; no thermal effects are possible for the low pulse repetition rates, supported by recent experiments. New results show that the dielectric sample exposed to nanopulses behaves as a dielectric resonator. For a sample in a cuvette, we obtained the dominant resonant frequency and the Q-factor of the resonator

Global solubility of the three-dimensional Navier-Stokes equations with uniformly large initial vorticity

International Nuclear Information System (INIS)

Makhalov, A S; Nikolaenko, V P

2003-01-01

This paper is a survey of results concerning the three-dimensional Navier-Stokes and Euler equations with initial data characterized by uniformly large vorticity. The existence of regular solutions of the three-dimensional Navier-Stokes equations on an unbounded time interval is proved for large initial data both in R 3 and in bounded cylindrical domains. Moreover, the existence of smooth solutions on large finite time intervals is established for the three-dimensional Euler equations. These results are obtained without additional assumptions on the behaviour of solutions for t>0. Any smooth solution is not close to any two-dimensional manifold. Our approach is based on the computation of singular limits of rapidly oscillating operators, non-linear averaging, and a consideration of the mutual absorption of non-linear oscillations of the vorticity field. The use of resonance conditions, methods from the theory of small divisors, and non-linear averaging of almost periodic functions leads to the limit resonant Navier-Stokes equations. Global solubility of these equations is proved without any conditions on the three-dimensional initial data. The global regularity of weak solutions of three-dimensional Navier-Stokes equations with uniformly large vorticity at t=0 is proved by using the regularity of weak solutions and the strong convergence

Three-dimensional bio-printing.

Science.gov (United States)

Gu, Qi; Hao, Jie; Lu, YangJie; Wang, Liu; Wallace, Gordon G; Zhou, Qi

2015-05-01

Three-dimensional (3D) printing technology has been widely used in various manufacturing operations including automotive, defence and space industries. 3D printing has the advantages of personalization, flexibility and high resolution, and is therefore becoming increasingly visible in the high-tech fields. Three-dimensional bio-printing technology also holds promise for future use in medical applications. At present 3D bio-printing is mainly used for simulating and reconstructing some hard tissues or for preparing drug-delivery systems in the medical area. The fabrication of 3D structures with living cells and bioactive moieties spatially distributed throughout will be realisable. Fabrication of complex tissues and organs is still at the exploratory stage. This review summarize the development of 3D bio-printing and its potential in medical applications, as well as discussing the current challenges faced by 3D bio-printing.

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

International Nuclear Information System (INIS)

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

1985-01-01

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

Radiological evaluation of the fetal face using three-dimensional ultrasound imaging

Directory of Open Access Journals (Sweden)

Bäumler M

2012-12-01

Full Text Available Marcel Bäumler,1–3 Michèle Bigorre,1,4 Jean-Michel Faure1,51CHU Montpellier, Centre de Compétence des Fentes Faciales, Hôpital Lapeyronie, Montpellier, 2Clinique du Parc, Imagerie de la Femme, Castelnau-le-Lez, 3Cabinet de Radiologie du Trident, Lunel, 4CHU Service de Chirurgie Plastique Pédiatrique, Hôpital Lapeyronie, Montpellier, 5CHU Montpellier, Service de Gynécologie-Obstétrique, Hôpital Arnaud de Villeneuve, Montpellier, FranceAbstract: This paper reviews screening and three-dimensional diagnostic ultrasound imaging of the fetal face. The different techniques available for analyzing biometric and morphological items of the profile, eyes, ears, lips, and hard and soft palate are commented on and briefly compared with the respective bi-dimensional techniques. The available literature supports the use of three-dimensional ultrasound in difficult prenatal diagnostic conditions because of its diagnostic accuracy, enabling improved safety of perinatal care. Globally, a marked increase has been observed in the accuracy of three-dimensional ultrasound in comparison with the bi-dimensional approach. Because there is no consensus about the performance of the different three-dimensional techniques, future studies are needed in order to compare them and to find the best technique for analysis of each of the respective facial elements. Universal prenatal standards may integrate these potential new findings in the future. At this time, the existing guidelines for prenatal facial screening should not be changed.Keywords: prenatal three-dimensional ultrasound, prenatal screening, prenatal diagnosis, cleft lip and palate, fetal profile, retrognathism

Three dimensional periodic foundations for base seismic isolation

International Nuclear Information System (INIS)

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

2015-01-01

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

Simulation on three dimensional bubble formation using MARS

International Nuclear Information System (INIS)

Kunugi, Tomoaki

1997-01-01

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

Reliability of tunnel angle in ACL reconstruction: two-dimensional versus three-dimensional guide technique.

Science.gov (United States)

Leiter, Jeff R S; de Korompay, Nevin; Macdonald, Lindsey; McRae, Sheila; Froese, Warren; Macdonald, Peter B

2011-08-01

To compare the reliability of tibial tunnel position and angle produced with a standard ACL guide (two-dimensional guide) or Howell 65° Guide (three-dimensional guide) in the coronal and sagittal planes. In the sagittal plane, the dependent variables were the angle of the tibial tunnel relative to the tibial plateau and the position of the tibial tunnel with respect to the most posterior aspect of the tibia. In the coronal plane, the dependent variables were the angle of the tunnel with respect to the medial joint line of the tibia and the medial and lateral placement of the tibial tunnel relative to the most medial aspect of the tibia. The position and angle of the tibial tunnel in the coronal and sagittal planes were determined from anteroposterior and lateral radiographs, respectively, taken 2-6 months postoperatively. The two-dimensional and three-dimensional guide groups included 28 and 24 sets of radiographs, respectively. Tibial tunnel position was identified, and tunnel angle measurements were completed. Multiple investigators measured the position and angle of the tunnel 3 times, at least 7 days apart. The angle of the tibial tunnel in the coronal plane using a two-dimensional guide (61.3 ± 4.8°) was more horizontal (P guide (64.7 ± 6.2°). The position of the tibial tunnel in the sagittal plane was more anterior (P guide group compared to the three-dimensional guide group (43.3 ± 2.9%). The Howell Tibial Guide allows for reliable placement of the tibial tunnel in the coronal plane at an angle of 65°. Tibial tunnels were within the anatomical footprint of the ACL with either technique. Future studies should investigate the effects of tibial tunnel angle on knee function and patient quality of life. Case-control retrospective comparative study, Level III.

Three-dimensional spin-3 theories based on general kinematical algebras

Energy Technology Data Exchange (ETDEWEB)

Bergshoeff, Eric [Van Swinderen Institute for Particle Physics and Gravity, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Grumiller, Daniel; Prohazka, Stefan [Institute for Theoretical Physics, TU Wien,Wiedner Hauptstrasse 8-10/136, A-1040 Vienna (Austria); Rosseel, Jan [Albert Einstein Center for Fundamental Physics, University of Bern,Sidlerstrasse 5, 3012 Bern (Switzerland); Faculty of Physics, University of Vienna,Boltzmanngasse 5, A-1090 Vienna (Austria)

2017-01-25

We initiate the study of non- and ultra-relativistic higher spin theories. For sake of simplicity we focus on the spin-3 case in three dimensions. We classify all kinematical algebras that can be obtained by all possible Inönü-Wigner contraction procedures of the kinematical algebra of spin-3 theory in three dimensional (anti-) de Sitter space-time. We demonstrate how to construct associated actions of Chern-Simons type, directly in the ultra-relativistic case and by suitable algebraic extensions in the non-relativistic case. We show how to give these kinematical algebras an infinite-dimensional lift by imposing suitable boundary conditions in a theory we call “Carroll Gravity”, whose asymptotic symmetry algebra turns out to be an infinite-dimensional extension of the Carroll algebra.

Three-dimensional reactor dynamics code for VVER type nuclear reactors

Energy Technology Data Exchange (ETDEWEB)

Kyrki-Rajamaeki, R. [VTT Energy, Espoo (Finland)

1995-10-01

A three-dimensional reactor dynamics computer code has been developed, validated and applied for transient and accident analyses of VVER type nuclear reactors. This code, HEXTRAN, is a part of the reactor physics and dynamics calculation system of the Technical Research Centre of Finland, VTT. HEXTRAN models accurately the VVER core with hexagonal fuel assemblies. The code uses advanced mathematical methods in spatial and time discretization of neutronics, heat transfer and the two-phase flow equations of hydraulics. It includes all the experience of VTT from 20 years on the accurate three-dimensional static reactor physics as well as on the one-dimensional reactor dynamics. The dynamic coupling with the thermal hydraulic system code SMABRE also allows the VVER circuit-modelling experience to be included in the analyses. (79 refs.).

Three-dimensional reactor dynamics code for VVER type nuclear reactors

International Nuclear Information System (INIS)

Kyrki-Rajamaeki, R.

1995-10-01

A three-dimensional reactor dynamics computer code has been developed, validated and applied for transient and accident analyses of VVER type nuclear reactors. This code, HEXTRAN, is a part of the reactor physics and dynamics calculation system of the Technical Research Centre of Finland, VTT. HEXTRAN models accurately the VVER core with hexagonal fuel assemblies. The code uses advanced mathematical methods in spatial and time discretization of neutronics, heat transfer and the two-phase flow equations of hydraulics. It includes all the experience of VTT from 20 years on the accurate three-dimensional static reactor physics as well as on the one-dimensional reactor dynamics. The dynamic coupling with the thermal hydraulic system code SMABRE also allows the VVER circuit-modelling experience to be included in the analyses. (79 refs.)

Resonance phenomena in a time-dependent, three-dimensional model of an idealized eddy

Science.gov (United States)

Rypina, I. I.; Pratt, L. J.; Wang, P.; Äe; -zgökmen, T. M.; Mezic, I.

2015-08-01

We analyze the geometry of Lagrangian motion and material barriers in a time-dependent, three-dimensional, Ekman-driven, rotating cylinder flow, which serves as an idealization for an isolated oceanic eddy and other overturning cells with cylindrical geometry in the ocean and atmosphere. The flow is forced at the top through an oscillating upper lid, and the response depends on the frequency and amplitude of lid oscillations. In particular, the Lagrangian geometry changes near the resonant tori of the unforced flow, whose frequencies are rationally related to the forcing frequencies. Multi-scale analytical expansions are used to simplify the flow in the vicinity of resonant trajectories and to investigate the resonant flow geometries. The resonance condition and scaling can be motivated by simple physical argument. The theoretically predicted flow geometries near resonant trajectories have then been confirmed through numerical simulations in a phenomenological model and in a full solution of the Navier-Stokes equations.

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

Science.gov (United States)

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

2017-09-28

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

Analysis of diagnositc accuracy with CT-guided percutaneous transthoracic lung biopsy for pulmonary lesions

International Nuclear Information System (INIS)

Wang Haiyan; Zhuang Yiping; Zhang Jin; Feng Yong; Zhang Xiao; Xu Lin

2007-01-01

Objective: To evaluate the factors which may affect the diagnostic accmracy of CT-guided percutaneous transthoracic lung biopsy for pulmonary lesions. Methods: CT-guided percutaneous transthoracic lung biopsy was performed in 264 patients, all of which were proved by surgical pathology or clinical follow-up. A logistic regression analysis was used to investigate the relationship between the location and the size of the lesions and insertion depth of biopsy needles and the diagnostic accuracy of CT-guided percutaneous transthomcic lung biopsy. The complication rate including pneumatothorax and bleeding rate were record. Results: The diagnostic accuracy was 87.5%. Both the pneumothorax and the bleeding of lesion were 1.9%. The size of lesion was suggested by Logistic regression analysis had a significant influence on the diagnostic accuracy (Wald=12.891, P=0.00034, OR=0.96). Conclusion: CT-guided pereumneous transthoracic lung biopsy has a high diagnostic accuracy for pulmonary lesions. The size of the lesions had significant effect on the diagnostic accuracy. (authors)

Three-dimensional tori and Arnold tongues

Energy Technology Data Exchange (ETDEWEB)

Sekikawa, Munehisa, E-mail: sekikawa@cc.utsunomiya-u.ac.jp [Department of Mechanical and Intelligent Engineering, Utsunomiya University, Utsunomiya-shi 321-8585 (Japan); Inaba, Naohiko [Organization for the Strategic Coordination of Research and Intellectual Property, Meiji University, Kawasaki-shi 214-8571 (Japan); Kamiyama, Kyohei [Department of Electronics and Bioinformatics, Meiji University, Kawasaki-shi 214-8571 (Japan); Aihara, Kazuyuki [Institute of Industrial Science, the University of Tokyo, Meguro-ku 153-8505 (Japan)

2014-03-15

This study analyzes an Arnold resonance web, which includes complicated quasi-periodic bifurcations, by conducting a Lyapunov analysis for a coupled delayed logistic map. The map can exhibit a two-dimensional invariant torus (IT), which corresponds to a three-dimensional torus in vector fields. Numerous one-dimensional invariant closed curves (ICCs), which correspond to two-dimensional tori in vector fields, exist in a very complicated but reasonable manner inside an IT-generating region. Periodic solutions emerge at the intersections of two different thin ICC-generating regions, which we call ICC-Arnold tongues, because all three independent-frequency components of the IT become rational at the intersections. Additionally, we observe a significant bifurcation structure where conventional Arnold tongues transit to ICC-Arnold tongues through a Neimark-Sacker bifurcation in the neighborhood of a quasi-periodic Hopf bifurcation (or a quasi-periodic Neimark-Sacker bifurcation) boundary.

Development of three-dimensional computed tomography system using TNRF2 of JRR-3M

Energy Technology Data Exchange (ETDEWEB)

Murata, Yutaka; Mochiki, Koh-ichi [Musashi Inst. of Tech., Tokyo (Japan); Matsubayashi, Masahito

1998-01-01

A three-dimensional filtering engine, a convolution engine, and a back projection engine were developed for real-time signal processing of three-dimensional computed tomography. The performance of the system was measured and through-put of 0.5 second per one cross sectional data processing was attained. (author)

Terahertz Imaging of Three-Dimensional Dehydrated Breast Cancer Tumors

Science.gov (United States)

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.

Real-time monitoring of cisplatin cytotoxicity on three-dimensional spheroid tumor cells

Directory of Open Access Journals (Sweden)

Baek NH

2016-07-01

Full Text Available NamHuk Baek,1,* Ok Won Seo,1,* Jaehwa Lee,1 John Hulme,2 Seong Soo A An2 1Department of Research and Development, NanoEntek Inc., Seoul, 2Department of BioNano Technology, Gachon University, Gyeonggi-do, Korea *These authors contributed equally to this work Abstract: Three-dimensional (3D cell cultivation is a powerful technique for monitoring and understanding diverse cellular mechanisms in developmental cancer and neuronal biology, tissue engineering, and drug development. 3D systems could relate better to in vivo models than two-dimensional (2D cultures. Several factors, such as cell type, survival rate, proliferation rate, and gene and protein expression patterns, determine whether a particular cell line can be adapted to a 3D system. The 3D system may overcome some of the limitations of 2D cultures in terms of cell–cell communication and cell networks, which are essential for understanding differentiation, structural organization, shape, and extended connections with other cells or organs. Here, the effect of the anticancer drug cisplatin, also known as cis-diamminedichloroplatinum (II or CDDP, on adenosine triphosphate (ATP generation was investigated using 3D spheroid-forming cells and real-time monitoring for 7 days. First, 12 cell lines were screened for their ability to form 3D spheroids: prostate (DU145, testis (F9, embryonic fibroblast (NIH-3T3, muscle (C2C12, embryonic kidney (293T, neuroblastoma (SH-SY5Y, adenocarcinomic alveolar basal epithelial cell (A549, cervical cancer (HeLa, HeLa contaminant (HEp2, pituitary epithelial-like cell (GH3, embryonic cell (PA317, and osteosarcoma (U-2OS cells. Of these, eight cell lines were selected: NIH-3T3, C2C12, 293T, SH-SY5Y, A549, HeLa, PA317, and U-2OS; and five underwent real-time monitoring of CDDP cytotoxicity: HeLa, A549, 293T, SH-SY5Y, and U-2OS. ATP generation was blocked 1 day after addition of 50 µM CDDP, but cytotoxicity in HeLa, A549, SH-SY5Y, and U-2OS cells could be

A study of the application of singular perturbation theory. [development of a real time algorithm for optimal three dimensional aircraft maneuvers

Science.gov (United States)

Mehra, R. K.; Washburn, R. B.; Sajan, S.; Carroll, J. V.

1979-01-01

A hierarchical real time algorithm for optimal three dimensional control of aircraft is described. Systematic methods are developed for real time computation of nonlinear feedback controls by means of singular perturbation theory. The results are applied to a six state, three control variable, point mass model of an F-4 aircraft. Nonlinear feedback laws are presented for computing the optimal control of throttle, bank angle, and angle of attack. Real Time capability is assessed on a TI 9900 microcomputer. The breakdown of the singular perturbation approximation near the terminal point is examined Continuation methods are examined to obtain exact optimal trajectories starting from the singular perturbation solutions.

Fabrication of three-dimensional micro-nanofiber structures by a novel solution blow spinning device

Directory of Open Access Journals (Sweden)

Feng Liang

2017-02-01

Full Text Available The fabrication of three-dimensional scaffolds has attracted more attention in tissue engineering. The purpose of this study is to explore a new method for the fabrication of three-dimensional micro-nanofiber structures by combining solution blow spinning and rotating collector. In this study, we successfully fabricated fibers with a minimum diameter of 200 nm and a three-dimensional structure with a maximum porosity of 89.9%. At the same time, the influence of various parameters such as the solvent volatility, the shape of the collector, the feed rate of the solution and the applied gas pressure were studied. It is found that solvent volatility has large effect on the formation of the three-dimensional shape of the structure. The shape of the collector affects the porosity and fiber distribution of the three-dimensional structure. The fiber diameter and fiber uniformity can be controlled by adjusting the solution feed rate and the applied gas pressure. It is feasible to fabricate high-quality three-dimensional micro-nanofiber structure by this new method, which has great potential in tissue engineering.

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

Directory of Open Access Journals (Sweden)

Feroze Mahmood

2014-01-01

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

Three-Dimensional Computer-Assisted Two-Layer Elastic Models of the Face.

Science.gov (United States)

Ueda, Koichi; Shigemura, Yuka; Otsuki, Yuki; Fuse, Asuka; Mitsuno, Daisuke

2017-11-01

To make three-dimensional computer-assisted elastic models for the face, we decided on five requirements: (1) an elastic texture like skin and subcutaneous tissue; (2) the ability to take pen marking for incisions; (3) the ability to be cut with a surgical knife; (4) the ability to keep stitches in place for a long time; and (5) a layered structure. After testing many elastic solvents, we have made realistic three-dimensional computer-assisted two-layer elastic models of the face and cleft lip from the computed tomographic and magnetic resonance imaging stereolithographic data. The surface layer is made of polyurethane and the inner layer is silicone. Using this elastic model, we taught residents and young doctors how to make several typical local flaps and to perform cheiloplasty. They could experience realistic simulated surgery and understand three-dimensional movement of the flaps.

Three-dimensional CT of the pediatric spine

International Nuclear Information System (INIS)

Starshak, R.J.; Crawford, C.R.; Waisman, R.C.; Sty, J.R.

1987-01-01

CT of the spine has been shown to be useful in evaluating congenital, neoplastic, inflammatory, and traumatic lesions. Any portion of the neural arch may be involved by these disease processes. However, the complex nature of the spinal column can make evaluation of these abnormalities difficult on axial CT. This is especially true if the spine is distorted by scoliosis, kyphosis, or lordosis. The principal advantage of three-dimensional CT is its ability to display the surface relationships of complicated objects. The complexity of the spinal axis makes it ideal for study with three-dimensional CT. This presentation illustrates the advantages and drawbacks of three-dimensional CT in spinal abnormalities in children

The effect of base image window level selection on the dimensional measurement accuracy of resultant three-dimensional image displays

International Nuclear Information System (INIS)

Kurmis, A.P.; Hearn, T.C.; Reynolds, K.J.

2003-01-01

Purpose: The aim of this study was to determine the effect of base image window level selection on direct linear measurement of knee structures displayed using new magnetic resonance (MR)-based three-dimensional reconstructed computer imaging techniques. Methods: A prospective comparative study was performed using a series of three-dimensional knee images, generated from conventional MR imaging (MRI) sections. Thirty distinct anatomical structural features were identified within the image series of which repeated measurements were compared at 10 different window grey scale levels. Results: Statistical analysis demonstrated an excellent raw correlation between measurements and suggested no significant difference between measurements made at each of the 10 window level settings (P>0.05). Conclusions: The findings of this study suggest that unlike conventional MR or CT applications, grey scale window level selection at the time of imaging does not significantly affect the visual quality of resultant three-dimensional reconstructed images and hence the accuracy of subsequent direct linear measurement. The diagnostic potential of clinical progression from routine two-dimensional to advanced three-dimensional reconstructed imaging techniques may therefore be less likely to be degraded by inappropriate MR technician image windowing during the capturing of image series

Recent Inferior Myocardial Infarction Complicated with a Right Ventricular Thrombus Detected by Three Cardiac Imaging Modalities.

Science.gov (United States)

Kuno, Toshiki; Imaeda, Syohei; Hashimoto, Kenji; Ryuzaki, Toshinobu; Saito, Tetsuya; Yamazaki, Hiroyuki; Tabei, Ryota; Kodaira, Masaki; Hase, Manabu; Numasawa, Yohei

2018-03-01

We report the case of a 71-year-old woman diagnosed with recent inferior myocardial infarction complicated with right ventricular infarction and a right ventricular thrombus. Three-dimensional transthoracic echocardiography, contrast-enhanced computed tomography, and cardiac magnetic resonance imaging clearly detected a thrombus. We consider cases with a recent right ventricular infarction to require assessment for thrombus formations in the right ventricle. Fortunately, vigorous anticoagulation therapy resolved the thrombi in both the right ventricle and right coronary artery.

Three-dimensional deformation of orthodontic brackets

Science.gov (United States)

Melenka, Garrett W; Nobes, David S; Major, Paul W

2013-01-01

Braces are used by orthodontists to correct the misalignment of teeth in the mouth. Archwire rotation is a particular procedure used to correct tooth inclination. Wire rotation can result in deformation to the orthodontic brackets, and an orthodontic torque simulator has been designed to examine this wire–bracket interaction. An optical technique has been employed to measure the deformation due to size and geometric constraints of the orthodontic brackets. Images of orthodontic brackets are collected using a stereo microscope and two charge-coupled device cameras, and deformation of orthodontic brackets is measured using a three-dimensional digital image correlation technique. The three-dimensional deformation of orthodontic brackets will be evaluated. The repeatability of the three-dimensional digital image correlation measurement method was evaluated by performing 30 archwire rotation tests using the same bracket and archwire. Finally, five Damon 3MX and five In-Ovation R self-ligating brackets will be compared using this technique to demonstrate the effect of archwire rotation on bracket design. PMID:23762201

Three-dimensional deformation of orthodontic brackets.

Science.gov (United States)

Melenka, Garrett W; Nobes, David S; Major, Paul W; Carey, Jason P

2013-01-01

Braces are used by orthodontists to correct the misalignment of teeth in the mouth. Archwire rotation is a particular procedure used to correct tooth inclination. Wire rotation can result in deformation to the orthodontic brackets, and an orthodontic torque simulator has been designed to examine this wire-bracket interaction. An optical technique has been employed to measure the deformation due to size and geometric constraints of the orthodontic brackets. Images of orthodontic brackets are collected using a stereo microscope and two charge-coupled device cameras, and deformation of orthodontic brackets is measured using a three-dimensional digital image correlation technique. The three-dimensional deformation of orthodontic brackets will be evaluated. The repeatability of the three-dimensional digital image correlation measurement method was evaluated by performing 30 archwire rotation tests using the same bracket and archwire. Finally, five Damon 3MX and five In-Ovation R self-ligating brackets will be compared using this technique to demonstrate the effect of archwire rotation on bracket design.

Unsteady three-dimensional behavior of natural convection in horizontal annulus

International Nuclear Information System (INIS)

Ohya, Toshizo; Miki, Yasutomi; Morita, Kouji; Fukuda, Kenji; Hasegawa, Shu

1988-01-01

An numerical analysis has been performed on unsteady three-dimensional natural convection in a concentric horizontal annulus filled with air. The explicit leap-frog scheme is used for integrating three-dimensional time-dependent equations and the fast Fourier transform (FFT) for solving the Poisson equations for pressure. An oscillatory flow is found to occur at high Rayleigh numbers, which agree qualitatively with the experimental observation made by Bishop et al. An experiment is also conducted to measure temperature fluctuations; a comparison between periods of fluctuations obtained numerically and experimentally shows a good agreement. Numerical calculations yield various statistical parameters of turbulence at higher Rayleigh numbers, which wait experimental verificaions, however. (author)

Three-dimensional plasma equilibrium near a separatrix

International Nuclear Information System (INIS)

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

1988-08-01

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

Three-dimensional recurring patterns in excitable media

International Nuclear Information System (INIS)

Biton, Y.; Rabinovitch, A.; Braunstein, D.; Friedman, M.; Aviram, I.

2011-01-01

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.

Fine-grained information extraction from German transthoracic echocardiography reports.

Science.gov (United States)

Toepfer, Martin; Corovic, Hamo; Fette, Georg; Klügl, Peter; Störk, Stefan; Puppe, Frank

2015-11-12

Information extraction techniques that get structured representations out of unstructured data make a large amount of clinically relevant information about patients accessible for semantic applications. These methods typically rely on standardized terminologies that guide this process. Many languages and clinical domains, however, lack appropriate resources and tools, as well as evaluations of their applications, especially if detailed conceptualizations of the domain are required. For instance, German transthoracic echocardiography reports have not been targeted sufficiently before, despite of their importance for clinical trials. This work therefore aimed at development and evaluation of an information extraction component with a fine-grained terminology that enables to recognize almost all relevant information stated in German transthoracic echocardiography reports at the University Hospital of Würzburg. A domain expert validated and iteratively refined an automatically inferred base terminology. The terminology was used by an ontology-driven information extraction system that outputs attribute value pairs. The final component has been mapped to the central elements of a standardized terminology, and it has been evaluated according to documents with different layouts. The final system achieved state-of-the-art precision (micro average.996) and recall (micro average.961) on 100 test documents that represent more than 90 % of all reports. In particular, principal aspects as defined in a standardized external terminology were recognized with f 1=.989 (micro average) and f 1=.963 (macro average). As a result of keyword matching and restraint concept extraction, the system obtained high precision also on unstructured or exceptionally short documents, and documents with uncommon layout. The developed terminology and the proposed information extraction system allow to extract fine-grained information from German semi-structured transthoracic echocardiography reports

Metamorphosis revealed: time-lapse three-dimensional imaging inside a living chrysalis.

Science.gov (United States)

Lowe, Tristan; Garwood, Russell J; Simonsen, Thomas J; Bradley, Robert S; Withers, Philip J

2013-07-06

Studies of model insects have greatly increased our understanding of animal development. Yet, they are limited in scope to this small pool of model species: a small number of representatives for a hyperdiverse group with highly varied developmental processes. One factor behind this narrow scope is the challenging nature of traditional methods of study, such as histology and dissection, which can preclude quantitative analysis and do not allow the development of a single individual to be followed. Here, we use high-resolution X-ray computed tomography (CT) to overcome these issues, and three-dimensionally image numerous lepidopteran pupae throughout their development. The resulting models are presented in the electronic supplementary material, as are figures and videos, documenting a single individual throughout development. They provide new insight and details of lepidopteran metamorphosis, and allow the measurement of tracheal and gut volume. Furthermore, this study demonstrates early and rapid development of the tracheae, which become visible in scans just 12 h after pupation. This suggests that there is less remodelling of the tracheal system than previously expected, and is methodologically important because the tracheal system is an often-understudied character system in development. In the future, this form of time-lapse CT-scanning could allow faster and more detailed developmental studies on a wider range of taxa than is presently possible.

Advancing three-dimensional MEMS by complimentary laser micro manufacturing

Science.gov (United States)

Palmer, Jeremy A.; Williams, John D.; Lemp, Tom; Lehecka, Tom M.; Medina, Francisco; Wicker, Ryan B.

2006-01-01

This paper describes improvements that enable engineers to create three-dimensional MEMS in a variety of materials. It also provides a means for selectively adding three-dimensional, high aspect ratio features to pre-existing PMMA micro molds for subsequent LIGA processing. This complimentary method involves in situ construction of three-dimensional micro molds in a stand-alone configuration or directly adjacent to features formed by x-ray lithography. Three-dimensional micro molds are created by micro stereolithography (MSL), an additive rapid prototyping technology. Alternatively, three-dimensional features may be added by direct femtosecond laser micro machining. Parameters for optimal femtosecond laser micro machining of PMMA at 800 nanometers are presented. The technical discussion also includes strategies for enhancements in the context of material selection and post-process surface finish. This approach may lead to practical, cost-effective 3-D MEMS with the surface finish and throughput advantages of x-ray lithography. Accurate three-dimensional metal microstructures are demonstrated. Challenges remain in process planning for micro stereolithography and development of buried features following femtosecond laser micro machining.

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 m......-similar PDFs for longitudinal velocity differences are also presented for the rotating 3D turbulence case....

Investigation on the MOC with a linear source approximation scheme in three-dimensional assembly

International Nuclear Information System (INIS)

Zhu, Chenglin; Cao, Xinrong

2014-01-01

Method of characteristics (MOC) for solving neutron transport equation has already become one of the fundamental methods for lattice calculation of nuclear design code system. At present, MOC has three schemes to deal with the neutron source of the transport equation: the flat source approximation of the step characteristics (SC) scheme, the diamond difference (DD) scheme and the linear source (LS) characteristics scheme. The MOC for SC scheme and DD scheme need large storage space and long computing time when they are used to calculate large-scale three-dimensional neutron transport problems. In this paper, a LS scheme and its correction for negative source distribution were developed and added to DRAGON code. This new scheme was compared with the SC scheme and DD scheme which had been applied in this code. As an open source code, DRAGON could solve three-dimensional assembly with MOC method. Detailed calculation is conducted on two-dimensional VVER-1000 assembly under three schemes of MOC. The numerical results indicate that coarse mesh could be used in the LS scheme with the same accuracy. And the LS scheme applied in DRAGON is effective and expected results are achieved. Then three-dimensional cell problem and VVER-1000 assembly are calculated with LS scheme and SC scheme. The results show that less memory and shorter computational time are employed in LS scheme compared with SC scheme. It is concluded that by using LS scheme, DRAGON is able to calculate large-scale three-dimensional problems with less storage space and shorter computing time

STAB: A kinetic, three-dimensional, one-group digital computer program

International Nuclear Information System (INIS)

Curtis, A.R.; Tyror, J.G.; Wrigley, H.E.

1961-10-01

A computer program for solving the one-group, time dependent, three-dimensional diffusion equation together with auxiliary equations representing heat transfer, xenon production and control rod movements, is presented. The equations and the methods of solution are discussed. (author)

Three-dimensional image signals: processing methods

Science.gov (United States)

Schiopu, Paul; Manea, Adrian; Craciun, Anca-Ileana; Craciun, Alexandru

2010-11-01

Over the years extensive studies have been carried out to apply coherent optics methods in real-time processing, communications and transmission image. This is especially true when a large amount of information needs to be processed, e.g., in high-resolution imaging. The recent progress in data-processing networks and communication systems has considerably increased the capacity of information exchange. We describe the results of literature investigation research of processing methods for the signals of the three-dimensional images. All commercially available 3D technologies today are based on stereoscopic viewing. 3D technology was once the exclusive domain of skilled computer-graphics developers with high-end machines and software. The images capture from the advanced 3D digital camera can be displayed onto screen of the 3D digital viewer with/ without special glasses. For this is needed considerable processing power and memory to create and render the complex mix of colors, textures, and virtual lighting and perspective necessary to make figures appear three-dimensional. Also, using a standard digital camera and a technique called phase-shift interferometry we can capture "digital holograms." These are holograms that can be stored on computer and transmitted over conventional networks. We present some research methods to process "digital holograms" for the Internet transmission and results.

Evaluation of left ventricular function in maintained hemodialysis patients using real-time three-dimensional echocardiography

International Nuclear Information System (INIS)

Wang Ling; Wang Jing; Zheng Min; Zhang Chunmei; Li Chan

2010-01-01

Objective: Using magnetic resonance imaging (MRI) technique as control standard, to explore the feasibility and accuracy of true real-time three-dimensional volume quantitative techniques (RT-3DE) in evaluation of the left ventricular volume (LVV) and left ventricular ejection fraction (LVEF) of the maintained hemodialysis (MHD) patients. Methods: 48 MHD patients were enrolled in this study. RT-3DE was used to detect the LVV and LVEF, while Simpson's method and M-Teichholz method were used at the same time. The results of the three methods were compared with the data measured by MRI. Results: (1)The data measured by RT-3DE method showed a highly positive correlation with the LVV detected by MRI (r=0.90, P 0.05). (2)When heart cavity deformed, the results of left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV) measured by M-Teichholz method and Simpson's method were higher or lower than the data measured by RT-3DE method, and the differences were statistically significant (all P<0.05). Conclusion: RT-3DE can accurately measure the volume of normal cardiac chambers and the left ventricular cavity deformation volume. The result of RT-3DE has higher accuracy compared with Simpson's method and M-Teichholz method. (authors)

Multimodal registration of three-dimensional maxillodental cone beam CT and photogrammetry data over time.

Science.gov (United States)

Bolandzadeh, N; Bischof, W; Flores-Mir, C; Boulanger, P

2013-01-01

In recent years, one of the foci of orthodontics has been on systems for the evaluation of treatment results and the tracking of tissue variations over time. This can be accomplished through analysing three-dimensional orthodontic images obtained before and after the treatments. Since complementary information is achieved by integrating multiple imaging modalities, cone beam CT (CBCT) and stereophotogrammetry technologies are used in this study to develop a method for tracking bone, teeth and facial soft-tissue variations over time. We propose a two-phase procedure of multimodal (Phase 1) and multitemporal (Phase 2) registration which aligns images taken from the same patient by different imaging modalities and at different times. Extrinsic (for Phase 1) and intrinsic (for Phase 2) landmark-based registration methods are employed as an initiation for a robust iterative closest points algorithm. Since the mandible moves independently of the upper skull, the registration procedure is applied separately on the mandible and the upper skull. The results show that the signed error distributions of both mandible and skull registrations follow a mixture of two Gaussian distributions, corresponding to alignment errors (due to our method) and temporal change over time. We suggest that the large values among the total registration errors correspond to the temporal change resulting from (1) the effect of treatment (i.e. the orthodontic changes of teeth positions); (2) the biological changes such as teeth growth over time, especially for teenagers; and (3) the segmentation procedure and CBCT precision change over time.

Development of a Three-Dimensional Hand Model Using Three-Dimensional Stereophotogrammetry: Assessment of Image Reproducibility.

Directory of Open Access Journals (Sweden)

Inge A Hoevenaren

Full Text Available Using three-dimensional (3D stereophotogrammetry precise images and reconstructions of the human body can be produced. Over the last few years, this technique is mainly being developed in the field of maxillofacial reconstructive surgery, creating fusion images with computed tomography (CT data for precise planning and prediction of treatment outcome. Though, in hand surgery 3D stereophotogrammetry is not yet being used in clinical settings.A total of 34 three-dimensional hand photographs were analyzed to investigate the reproducibility. For every individual, 3D photographs were captured at two different time points (baseline T0 and one week later T1. Using two different registration methods, the reproducibility of the methods was analyzed. Furthermore, the differences between 3D photos of men and women were compared in a distance map as a first clinical pilot testing our registration method.The absolute mean registration error for the complete hand was 1.46 mm. This reduced to an error of 0.56 mm isolating the region to the palm of the hand. When comparing hands of both sexes, it was seen that the male hand was larger (broader base and longer fingers than the female hand.This study shows that 3D stereophotogrammetry can produce reproducible images of the hand without harmful side effects for the patient, so proving to be a reliable method for soft tissue analysis. Its potential use in everyday practice of hand surgery needs to be further explored.

Computational study of three-dimensional wake structure

International Nuclear Information System (INIS)

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

1986-01-01

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

Standalone visualization tool for three-dimensional DRAGON geometrical models

International Nuclear Information System (INIS)

Lukomski, A.; McIntee, B.; Moule, D.; Nichita, E.

2008-01-01

DRAGON is a neutron transport and depletion code able to solve one-, two- and three-dimensional problems. To date DRAGON provides two visualization modules, able to represent respectively two- and three-dimensional geometries. The two-dimensional visualization module generates a postscript file, while the three dimensional visualization module generates a MATLAB M-file with instructions for drawing the tracks in the DRAGON TRACKING data structure, which implicitly provide a representation of the geometry. The current work introduces a new, standalone, tool based on the open-source Visualization Toolkit (VTK) software package which allows the visualization of three-dimensional geometrical models by reading the DRAGON GEOMETRY data structure and generating an axonometric image which can be manipulated interactively by the user. (author)

SNAP - a three dimensional neutron diffusion code

International Nuclear Information System (INIS)

McCallien, C.W.J.

1993-02-01

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

Three-dimensional fluorescence lifetime tomography

International Nuclear Information System (INIS)

Godavarty, Anuradha; Sevick-Muraca, Eva M.; Eppstein, Margaret J.

2005-01-01

Near-infrared fluorescence tomography using molecularly targeted lifetime-sensitive, fluorescent contrast agents have applications for early-stage cancer diagnostics. Yet, although the measurement of fluorescent lifetime imaging microscopy (FLIM) is extensively used in microscopy and spectroscopy applications, demonstration of fluorescence lifetime tomography for medical imaging is limited to two-dimensional studies. Herein, the feasibility of three-dimensional fluorescence-lifetime tomography on clinically relevant phantom volumes is established, using (i) a gain-modulated intensified charge coupled device (CCD) and modulated laser diode imaging system, (ii) two fluorescent contrast agents, e.g., Indocyanine green and 3-3'-Diethylthiatricarbocyanine iodide differing in their fluorescence lifetime by 0.62 ns, and (iii) a two stage approximate extended Kalman filter reconstruction algorithm. Fluorescence measurements of phase and amplitude were acquired on the phantom surface under different target to background fluorescence absorption (70:1, 100:1) and fluorescence lifetime (1:1, 2.1:1) contrasts at target depths of 1.4-2 cm. The Bayesian tomography algorithm was employed to obtain three-dimensional images of lifetime and absorption owing to the fluorophores

Parallelization characteristics of a three-dimensional whole-core code DeCART

International Nuclear Information System (INIS)

Cho, J. Y.; Joo, H.K.; Kim, H. Y.; Lee, J. C.; Jang, M. H.

2003-01-01

Neutron transport calculation for three-dimensional amount of computing time but also huge memory. Therefore, whole-core codes such as DeCART need both also parallel computation and distributed memory capabilities. This paper is to implement such parallel capabilities based on MPI grouping and memory distribution on the DeCART code, and then to evaluate the performance by solving the C5G7 three-dimensional benchmark and a simplified three-dimensional SMART core problem. In C5G7 problem with 24 CPUs, a speedup of maximum 22 is obtained on IBM regatta machine and 21 on a LINUX cluster for the MOC kernel, which indicates good parallel performance of the DeCART code. The simplified SMART problem which need about 11 GBytes memory with one processors requires about 940 MBytes, which means that the DeCART code can now solve large core problems on affordable LINUX clusters

Development of three dimensional solid modeler

International Nuclear Information System (INIS)

Zahoor, R.M.A.

1999-01-01

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

Quantification of plant cell coupling with three-dimensional photoactivation microscopy.

Science.gov (United States)

Liesche, J; Schulz, A

2012-07-01

Plant cells are directly connected by plasmodesmata that form channels through the cell wall and enable the intercellular movement of cytosolic solutes, membrane lipids and signalling molecules. Transport through plasmodesmata is regulated not only by a fixed size-exclusion limit, but also by physiological and pathological adaptation. To understand plant cell communication, carbon allocation and pathogen attack, the capacities for a specific molecule to pass a specific cell-wall interface is an essential parameter. So far, the degree of cell coupling was derived from frequency and diameter of plasmodesmata in relevant tissues as assessed by electron microscopy of fixed material. However, plasmodesmata functionality and capacity can only be determined in live material, not from electron microscopy, which is static and prone to fixation artefacts. Plasmodesmata functionality was a few times assessed using fluorescent tracers with diffusion properties similar to cytosolic solutes. Here, we used three-dimensional photoactivation microscopy to quantify plasmodesmata-mediated cell-wall permeability between living Cucurbita maxima leaf mesophyll cells with caged fluorescein as tracer. For the first time, all necessary functional and anatomical data were gathered for each individual cell from three-dimensional time series. This approach utilized a confocal microscope equipped with resonant scanner, which provides the high acquisition speed necessary to record optical sections of whole cells and offers time resolution high enough to follow the kinetics of photoactivation. The results were compared to two-dimensional measurements, which are shown to give a good estimate of cell coupling adequate for homogenous tissues. The two-dimensional approach is limited whenever tissues interfaces are studied that couple different cell types with diverse cell geometries. © 2011 The Authors Journal of Microscopy © 2011 Royal Microscopical Society.

The existence and regularity of time-periodic solutions to the three-dimensional Navier–Stokes equations in the whole space

International Nuclear Information System (INIS)

Kyed, Mads

2014-01-01

The existence, uniqueness and regularity of time-periodic solutions to the Navier–Stokes equations in the three-dimensional whole space are investigated. We consider the Navier–Stokes equations with a non-zero drift term corresponding to the physical model of a fluid flow around a body that moves with a non-zero constant velocity. The existence of a strong time-periodic solution is shown for small time-periodic data. It is further shown that this solution is unique in a large class of weak solutions that can be considered physically reasonable. Finally, we establish regularity properties for any strong solution regardless of its size. (paper)

Three dimensional animated images of anorectal malformations

International Nuclear Information System (INIS)

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

1996-01-01

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

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.

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 diffusion calculations of nuclear reactors

International Nuclear Information System (INIS)

Caspo, N.

1981-07-01

This work deals with the three dimensional calculation of nuclear reactors using the code TRITON. The purposes of the work were to perform three-dimensional computations of the core of the Soreq nuclear reactor and of the power reactor ZION and to validate the TRITON code. Possible applications of the TRITON code in Soreq reactor calculations and in power reactor research are suggested. (H.K.)

Study of three-dimensional image display by systemic CT

International Nuclear Information System (INIS)

Fujioka, Tadao; Ebihara, Yoshiyuki; Unei, Hiroshi; Hayashi, Masao; Shinohe, Tooru; Wada, Yuji; Sakai, Takatsugu; Kashima, Kenji; Fujita, Yoshihiro

1989-01-01

A head phantom for CT was scanned at 2 mm intervals from the cervix to the vertex in an attempt to obtain a three-dimensional image display of bones and facial epidermis from an ordinary axial image. Clinically, three-dimensional images were formed at eye sockets and hip joints. With the three-dimensional image using the head phantom, the entire head could be displayed at any angle. Clinically, images were obtained that could not be attained by ordinary CT scanning, such as broken bones in eye sockets and stereoscopic structure at the bottom of a cranium. The three-dimensional image display is considered to be useful in clinical diagnosis. (author)

Continuum modeling of three-dimensional truss-like space structures

Science.gov (United States)

Nayfeh, A. H.; Hefzy, M. S.

1978-01-01

A mathematical and computational analysis capability has been developed for calculating the effective mechanical properties of three-dimensional periodic truss-like structures. Two models are studied in detail. The first, called the octetruss model, is a three-dimensional extension of a two-dimensional model, and the second is a cubic model. Symmetry considerations are employed as a first step to show that the specific octetruss model has four independent constants and that the cubic model has two. The actual values of these constants are determined by averaging the contributions of each rod element to the overall structure stiffness. The individual rod member contribution to the overall stiffness is obtained by a three-dimensional coordinate transformation. The analysis shows that the effective three-dimensional elastic properties of both models are relatively close to each other.

Generation of three-dimensional prototype models based on cone beam computed tomography

Energy Technology Data Exchange (ETDEWEB)

Lambrecht, J.T.; Berndt, D.C.; Zehnder, M. [University of Basel, Department of Oral Surgery, University Hospital for Oral Surgery, Oral Radiology and Oral Medicine, Basel (Switzerland); Schumacher, R. [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Muttenz (Switzerland)

2009-03-15

The purpose of this study was to generate three-dimensional models based on digital volumetric data that can be used in basic and advanced education. Four sets of digital volumetric data were established by cone beam computed tomography (CBCT) (Accuitomo, J. Morita, Kyoto, Japan). Datasets were exported as Dicom formats and imported into Mimics and Magic software programs to separate the different tissues such as nerve, tooth and bone. These data were transferred to a Polyjet 3D Printing machine (Eden 330, Object, Israel) to generate the models. Three-dimensional prototype models of certain limited anatomical structures as acquired volumetrically were fabricated. Generating three-dimensional models based on CBCT datasets is possible. Automated routine fabrication of these models, with the given infrastructure, is too time-consuming and therefore too expensive. (orig.)

Generation of three-dimensional prototype models based on cone beam computed tomography

International Nuclear Information System (INIS)

Lambrecht, J.T.; Berndt, D.C.; Zehnder, M.; Schumacher, R.

2009-01-01

The purpose of this study was to generate three-dimensional models based on digital volumetric data that can be used in basic and advanced education. Four sets of digital volumetric data were established by cone beam computed tomography (CBCT) (Accuitomo, J. Morita, Kyoto, Japan). Datasets were exported as Dicom formats and imported into Mimics and Magic software programs to separate the different tissues such as nerve, tooth and bone. These data were transferred to a Polyjet 3D Printing machine (Eden 330, Object, Israel) to generate the models. Three-dimensional prototype models of certain limited anatomical structures as acquired volumetrically were fabricated. Generating three-dimensional models based on CBCT datasets is possible. Automated routine fabrication of these models, with the given infrastructure, is too time-consuming and therefore too expensive. (orig.)

Three-dimensional computerized tomography in mandibular condyle fractures

International Nuclear Information System (INIS)

Bermeo, Fausto; Salazar, Abad

2003-01-01

Now, car accidents are so commons, this associated to the high technology in produce automobiles make this type of accidents so serious and the consequences of mandibular condyle fractures are more commons and with more gravity, some of these patients, generally need a traqueostomy to be operated, that is why every second that we can save during the surgery is important. The normal exams as X rays and simple TAC give as an important idea but no complete, on the contrary the three-dimensional TAC permits to observe every damages and its exact location, this contribute to make a better surgery organization, the number and type of plates that we have to put and the better way to treat each case, that contribute to reduce time in operating theatre which is in benefit of the patient, diminishing risks in serious patients as they are, that is why we recommend the utilization of the three-dimensional TAC. (The author)

Newtonian heating effects in three-dimensional flow of viscoelastic fluid

International Nuclear Information System (INIS)

Qayyum, A.; Hayat, T.; Alhuthali, M. S.; Malaikah, H. M.

2014-01-01

A mathematical model is constructed to investigate the three-dimensional flow of a non-Newtonian fluid. An incompressible viscoelastic fluid is used in mathematical formulation. The conjugate convective process (in which heat the transfer rate from the bounding surface with a finite capacity is proportional to the local surface temperature) in three-dimensional flow of a differential type of non-Newtonian fluid is analyzed for the first time. Series solutions for the nonlinear differential system are computed. Plots are presented for the description of emerging parameters entering into the problem. It is observed that the conjugate heating phenomenon causes an appreciable increase in the temperature at the stretching wall. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

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...

Object tracking mask-based NLUT on GPUs for real-time generation of holographic videos of three-dimensional scenes.

Science.gov (United States)

Kwon, M-W; Kim, S-C; Yoon, S-E; Ho, Y-S; Kim, E-S

2015-02-09

A new object tracking mask-based novel-look-up-table (OTM-NLUT) method is proposed and implemented on graphics-processing-units (GPUs) for real-time generation of holographic videos of three-dimensional (3-D) scenes. Since the proposed method is designed to be matched with software and memory structures of the GPU, the number of compute-unified-device-architecture (CUDA) kernel function calls and the computer-generated hologram (CGH) buffer size of the proposed method have been significantly reduced. It therefore results in a great increase of the computational speed of the proposed method and enables real-time generation of CGH patterns of 3-D scenes. Experimental results show that the proposed method can generate 31.1 frames of Fresnel CGH patterns with 1,920 × 1,080 pixels per second, on average, for three test 3-D video scenarios with 12,666 object points on three GPU boards of NVIDIA GTX TITAN, and confirm the feasibility of the proposed method in the practical application of electro-holographic 3-D displays.

Depth-enhanced three-dimensional-two-dimensional convertible display based on modified integral imaging.

Science.gov (United States)

Park, Jae-Hyeung; Kim, Hak-Rin; Kim, Yunhee; Kim, Joohwan; Hong, Jisoo; Lee, Sin-Doo; Lee, Byoungho

2004-12-01

A depth-enhanced three-dimensional-two-dimensional convertible display that uses a polymer-dispersed liquid crystal based on the principle of integral imaging is proposed. In the proposed method, a lens array is located behind a transmission-type display panel to form an array of point-light sources, and a polymer-dispersed liquid crystal is electrically controlled to pass or to scatter light coming from these point-light sources. Therefore, three-dimensional-two-dimensional conversion is accomplished electrically without any mechanical movement. Moreover, the nonimaging structure of the proposed method increases the expressible depth range considerably. We explain the method of operation and present experimental results.

An algorithm for three-dimensional imaging in the positron camera

International Nuclear Information System (INIS)

Chen Kun; Ma Mei; Xu Rongfen; Shen Miaohe

1986-01-01

A mathematical algorithm of back-projection filtered for image reconstructions using two-dimensional signals detected from parallel multiwire proportional chambers is described. The approaches of pseudo three-dimensional and full three-dimensional image reconstructions are introduced, and the available point response functions are defined as well. The designing parameters and computation procedure of the full three-dimensional method is presented

Three-dimensional dynamics of protostellar evolution

International Nuclear Information System (INIS)

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

Two- and three-dimensional CT analysis of ankle fractures

International Nuclear Information System (INIS)

Magid, D.; Fishman, E.K.; Ney, D.R.; Kuhlman, J.E.

1988-01-01

CT with coronal and sagittal reformatting (two-dimensional CT) and animated volumetric image rendering (three-dimensional CT) was used to assess ankle fractures. Partial volume limits transaxial CT in assessments of horizontally oriented structures. Two-dimensional CT, being orthogonal to the plafond, superior mortise, talar dome, and tibial epiphysis, often provides the most clinically useful images. Two-dimensional CT is most useful in characterizing potentially confusing fractures, such as Tillaux (anterior tubercle), triplane, osteochondral talar dome, or nondisplaced talar neck fractures, and it is the best study to confirm intraarticular fragments. Two-and three-dimensional CT best indicate the percentage of articular surface involvement and best demonstrate postoperative results or complications (hardware migration, residual step-off, delayed union, DJD, AVN, etc). Animated three-dimensional images are the preferred means of integrating the two-dimensional findings for surgical planning, as these images more closely simulate the clinical problem

Evaluation of three-dimensional virtual perception of garments

Science.gov (United States)

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.

Global and exponential attractors of the three dimensional viscous primitive equations of large-scale moist atmosphere

OpenAIRE

You, Bo; Li, Fang

2016-01-01

This paper is concerned with the long-time behavior of solutions for the three dimensional viscous primitive equations of large-scale moist atmosphere. We prove the existence of a global attractor for the three dimensional viscous primitive equations of large-scale moist atmosphere by asymptotic a priori estimate and construct an exponential attractor by using the smoothing property of the semigroup generated by the three dimensional viscous primitive equations of large-scale moist atmosphere...

Three-dimensional reconstruction and visualization system for medical images

International Nuclear Information System (INIS)

Preston, D.F.; Batnitzky, S.; Kyo Rak Lee; Cook, P.N.; Cook, L.T.; Dwyer, S.J.

1982-01-01

A three-dimensional reconstruction and visualization system could be of significant advantage in medical application such as neurosurgery and radiation treatment planning. The reconstructed anatomic structures from CT head scans could be used in a head stereotactic system to help plan the surgical procedure and the radiation treatment for a brain lesion. Also, the use of three-dimensional reconstruction algorithm provides for quantitative measures such as volume and surface area estimation of the anatomic features. This aspect of the three-dimensional reconstruction system may be used to monitor the progress or staging of a disease and the effects of patient treatment. Two cases are presented to illustrate the three-dimensional surface reconstruction and visualization system

Three-dimensional labeling program for elucidation of the geometric properties of biological particles in three-dimensional space.

Science.gov (United States)

Nomura, A; Yamazaki, Y; Tsuji, T; Kawasaki, Y; Tanaka, S

1996-09-15

For all biological particles such as cells or cellular organelles, there are three-dimensional coordinates representing the centroid or center of gravity. These coordinates and other numerical parameters such as volume, fluorescence intensity, surface area, and shape are referred to in this paper as geometric properties, which may provide critical information for the clarification of in situ mechanisms of molecular and cellular functions in living organisms. We have established a method for the elucidation of these properties, designated the three-dimensional labeling program (3DLP). Algorithms of 3DLP are so simple that this method can be carried out through the use of software combinations in image analysis on a personal computer. To evaluate 3DLP, it was applied to a 32-cell-stage sea urchin embryo, double stained with FITC for cellular protein of blastomeres and propidium iodide for nuclear DNA. A stack of optical serial section images was obtained by confocal laser scanning microscopy. The method was found effective for determining geometric properties and should prove applicable to the study of many different kinds of biological particles in three-dimensional space.

Study on a new type variable valve lift timing mechanism with a three dimensional cam; Sanjigen cam ni yoru shinkahen valve lift timing kiko ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

Ogura, M; Song, C [Nippon Institute of Technology, Saitama (Japan)

1997-10-01

The variable valve timing mechanism was invented to get a torque band at wide engine speed, and to reduce a compression job and pumping loss by a miler cycle at partial load. In this paper, the new type variable valve timing mechanism applying a three dimensional cam was proposed. Also, the feature of mechanism and the control system was done obviously. Further, about a miler cycle, a thermodynamics -like consideration was described. 5 refs., 8 figs.

Analysis and validation of carbohydrate three-dimensional structures

International Nuclear Information System (INIS)

Lütteke, Thomas

2009-01-01

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

Progress of radiotherapy by three-dimensional treatment planning

International Nuclear Information System (INIS)

Imada, Hajime; Nomoto, Satoshi; Takahashi, Hiroyuki; Nakata, Hajime

1998-01-01

The recent progress of three-dimensional radiation treatment planning was reviewed. And clinical cases such as lung cancer and breast cancer are introduced. In the University of Occupational and Development Health, the treatment system FOCUS which is made up of CT simulator and linac was used mainly. Three-dimensional treatment planning was carried for about 90% of 330 patients who underwent radiotherapy for one year. The target becomes to be accurate and dose distribution with all CT slices in radiation field can be confirmed by using three-dimensional radiation treatment planning apparatus. High dose irradiation localized to tumor part is possible. Relations between total dose and volume of normal tissue and/or tumor can be estimated numerically and easily by DVH. A prediction of indication and affection became possible by this procedure. In conclusion, generalization of three-dimensional radiation treatment planning will bring progress of more effective radiotherapy with less adverse reaction. (K.H.). 21 refs

A Three-Dimensional Statistical Average Skull: Application of Biometric Morphing in Generating Missing Anatomy.

Science.gov (United States)

Teshima, Tara Lynn; Patel, Vaibhav; Mainprize, James G; Edwards, Glenn; Antonyshyn, Oleh M

2015-07-01

The utilization of three-dimensional modeling technology in craniomaxillofacial surgery has grown exponentially during the last decade. Future development, however, is hindered by the lack of a normative three-dimensional anatomic dataset and a statistical mean three-dimensional virtual model. The purpose of this study is to develop and validate a protocol to generate a statistical three-dimensional virtual model based on a normative dataset of adult skulls. Two hundred adult skull CT images were reviewed. The average three-dimensional skull was computed by processing each CT image in the series using thin-plate spline geometric morphometric protocol. Our statistical average three-dimensional skull was validated by reconstructing patient-specific topography in cranial defects. The experiment was repeated 4 times. In each case, computer-generated cranioplasties were compared directly to the original intact skull. The errors describing the difference between the prediction and the original were calculated. A normative database of 33 adult human skulls was collected. Using 21 anthropometric landmark points, a protocol for three-dimensional skull landmarking and data reduction was developed and a statistical average three-dimensional skull was generated. Our results show the root mean square error (RMSE) for restoration of a known defect using the native best match skull, our statistical average skull, and worst match skull was 0.58, 0.74, and 4.4  mm, respectively. The ability to statistically average craniofacial surface topography will be a valuable instrument for deriving missing anatomy in complex craniofacial defects and deficiencies as well as in evaluating morphologic results of surgery.

Computational methods for three-dimensional microscopy reconstruction

CERN Document Server

Frank, Joachim

2014-01-01

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

PARALLEL ALGORITHM FOR THREE-DIMENSIONAL STOKES FLOW SIMULATION USING BOUNDARY ELEMENT METHOD

Directory of Open Access Journals (Sweden)

D. G. Pribytok

2016-01-01

Full Text Available Parallel computing technique for modeling three-dimensional viscous flow (Stokes flow using direct boundary element method is presented. The problem is solved in three phases: sampling and construction of system of linear algebraic equations (SLAE, its decision and finding the velocity of liquid at predetermined points. For construction of the system and finding the velocity, the parallel algorithms using graphics CUDA cards programming technology have been developed and implemented. To solve the system of linear algebraic equations the implemented software libraries are used. A comparison of time consumption for three main algorithms on the example of calculation of viscous fluid motion in three-dimensional cavity is performed.

Three-dimensional tokamak equilibria and stellarators with two-dimensional magnetic symmetry

International Nuclear Information System (INIS)

Garabedian, P.R.

1997-01-01

Three-dimensional computer codes have been developed to simulate equilibrium, stability and transport in tokamaks and stellarators. Bifurcated solutions of the tokamak problem suggest that three-dimensional effects may be more important than has generally been thought. Extensive calculations have led to the discovery of a stellarator configuration with just two field periods and with aspect ratio 3.2 that has a magnetic field spectrum B mn with toroidal symmetry. Numerical studies of equilibrium, stability and transport for this new device, called the Modular Helias-like Heliac 2 (MHH2), will be presented. (author)

Three-dimensional localization of low activity gamma-ray sources in real-time scenarios

Energy Technology Data Exchange (ETDEWEB)

Sharma, Manish K., E-mail: mksrkf@mst.edu; Alajo, Ayodeji B.; Lee, Hyoung K.

2016-03-21

Radioactive source localization plays an important role in tracking radiation threats in homeland security tasks. Its real-time application requires computationally efficient and reasonably accurate algorithms even with limited data to support detection with minimum uncertainty. This paper describes a statistic-based grid-refinement method for backtracing the position of a gamma-ray source in a three-dimensional domain in real-time. The developed algorithm used measurements from various known detector positions to localize the source. This algorithm is based on an inverse-square relationship between source intensity at a detector and the distance from the source to the detector. The domain discretization was developed and implemented in MATLAB. The algorithm was tested and verified from simulation results of an ideal case of a point source in non-attenuating medium. Subsequently, an experimental validation of the algorithm was performed to determine the suitability of deploying this scheme in real-time scenarios. Using the measurements from five known detector positions and for a measurement time of 3 min, the source position was estimated with an accuracy of approximately 53 cm. The accuracy improved and stabilized to approximately 25 cm for higher measurement times. It was concluded that the error in source localization was primarily due to detection uncertainties. In verification and experimental validation of the algorithm, the distance between {sup 137}Cs source and any detector position was between 0.84 m and 1.77 m. The results were also compared with the least squares method. Since the discretization algorithm was validated with a weak source, it is expected that it can localize the source of higher activity in real-time. It is believed that for the same physical placement of source and detectors, a source of approximate activity 0.61–0.92 mCi can be localized in real-time with 1 s of measurement time and same accuracy. The accuracy and computational

Evaluation of diagnostic quality in musculoskeletal three-dimensional CT scans

International Nuclear Information System (INIS)

Vannier, M.W.; Hildebolt, C.F.; Gilula, L.A.; Sutherland, C.J.; Offutt, C.J.; Drebin, R.; Mantle, M.; Giordono, T.A.

1988-01-01

A major application of three-dimensional computed tomography (CT) is in the imaging of the skeleton. Three-dimensional CT has an important role in determining the presence and extent of congenital and acquired orthopedic abnormalities. The objective of this study was to compare the diagnostic sensitivity and specificity of three-dimensional CT, planar CT, and plain radiography in the detection and characterization of orthopedic abnormalities. Three-dimensional CT scan reconstructions were obtained by two methods, surface reconstruction and volumetric techniques. Seventy patients were imaged with CT, three-dimensional CT, and plain radiography. The consensus opinion of experts with access to all images plus clinical history, surgical findings, and follow-up findings were taken as truth. Expert radiologists read these cases in a blinded fashion. The results were compared using receiver operating characteristic (ROC) analysis. The diagnostic value of each three-dimensional reconstruction method and the parameters used to perform the reconstructions were evaluated

Three-dimensional S-wave tomography under Axial Seamount

Science.gov (United States)

Baillard, C.; Wilcock, W. S. D.; Arnulf, A. F.; Tolstoy, M.; Waldhauser, F.

2017-12-01

Axial Seamount is a submarine volcano located at the intersection of the Juande Fuca Ridge and the Cobb-Eickelberg hotspot 500 km off the coast of thenorthwestern United States. The seamount, which rises 1 km above the seafloor, ischaracterized by a shallow caldera that is elongated in the N-S direction, measure 8km by 3 km and sits on top of a 14 km by 3 km magma reservoir. Two eruptive eventsin 1998 and 2011 motivated the deployment in 2014 of a real time cabled observatorywithin the Axial caldera, as part of the Ocean Observatories Initiative (OOI).Theobservatory includes a network of seven seismometers that span the southern half ofthe caldera. Five months after the observatory came on-line in November 2014, thevolcano erupted on April 24, 2015. Well over 100,000 events were located in thevicinity of the caldera, delineating an outward dipping ring fault that extends fromnear the surface to the magma body at 2 km depth and which accommodatesinflation and deflation of the volcano.The initial earthquake locations have beenobtained with a one-dimensional velocity model but the travel time residuals suggeststrong heterogeneities. A three-dimensional P-wave velocity model, obtained bycombining multichannel and ocean bottom seismometer refraction data, is being usedto refine locations but the three-dimensional S-wave structure is presently unknown.In most mid-ocean ridge settings, the distribution of earthquakes is not conducive forjoint inversions for S-wave velocity and hypocentral parameters because there are fewcrossing ray paths but at Axial the presence of a ring fault that is seismically active atall depths on both the east and west side of the caldera, provides a reasonablegeometry for such efforts. We will present the results of joint inversions that assumethe existing three-dimensional P wave velocity model and solve for VP/VS structure andhypocentral parameters using LOTOS, an algorithm that solves the forward problemusing ray bending.The resulting model

Three-dimensional echocardiography of normal and pathologic mitral valve: a comparison with two-dimensional transesophageal echocardiography

NARCIS (Netherlands)

Salustri, A.; Becker, A. E.; van Herwerden, L.; Vletter, W. B.; ten Cate, F. J.; Roelandt, J. R.

1996-01-01

This study was done to ascertain whether three-dimensional echocardiography can facilitate the diagnosis of mitral valve abnormalities. The value of the additional information provided by three-dimensional echocardiography compared with two-dimensional multiplane transesophageal echocardiography for

Orthogonality measurements for multidimensional chromatography in three and higher dimensional separations.

Science.gov (United States)

Schure, Mark R; Davis, Joe M

2017-11-10

Orthogonality metrics (OMs) for three and higher dimensional separations are proposed as extensions of previously developed OMs, which were used to evaluate the zone utilization of two-dimensional (2D) separations. These OMs include correlation coefficients, dimensionality, information theory metrics and convex-hull metrics. In a number of these cases, lower dimensional subspace metrics exist and can be readily calculated. The metrics are used to interpret previously generated experimental data. The experimental datasets are derived from Gilar's peptide data, now modified to be three dimensional (3D), and a comprehensive 3D chromatogram from Moore and Jorgenson. The Moore and Jorgenson chromatogram, which has 25 identifiable 3D volume elements or peaks, displayed good orthogonality values over all dimensions. However, OMs based on discretization of the 3D space changed substantially with changes in binning parameters. This example highlights the importance in higher dimensions of having an abundant number of retention times as data points, especially for methods that use discretization. The Gilar data, which in a previous study produced 21 2D datasets by the pairing of 7 one-dimensional separations, was reinterpreted to produce 35 3D datasets. These datasets show a number of interesting properties, one of which is that geometric and harmonic means of lower dimensional subspace (i.e., 2D) OMs correlate well with the higher dimensional (i.e., 3D) OMs. The space utilization of the Gilar 3D datasets was ranked using OMs, with the retention times of the datasets having the largest and smallest OMs presented as graphs. A discussion concerning the orthogonality of higher dimensional techniques is given with emphasis on molecular diversity in chromatographic separations. In the information theory work, an inconsistency is found in previous studies of orthogonality using the 2D metric often identified as %O. A new choice of metric is proposed, extended to higher dimensions

Three-dimensional CT of the mandible

International Nuclear Information System (INIS)

Zinreich, S.J.; Price, J.C.; Wang, H.; Ahn, H.S.; Kashima, H.

1988-01-01

Seventeen patients with mandibular oblation for facial neoplasia, primary neoplasm, and trauma were evaluated with CT and three-dimensional CT. In eight of these patients, a computerized acrylic model was generated for preoperative planning and postoperative reconstruction. The ramus and body of the mandible were reconstructed with mirror image and fusion techniques. Reconstructions of the anterior mandible were generated from models including the midface, skull based, and residual mandibular fragments. The results are preliminary; however, the authors believe that these represent a powerful new tool and a significant advance in mandibular reconstructive technique, reduced anesthesia time, and the optimized restoration of dental alignment and facial contour

Three-dimensional disc-satellite interaction: torques, migration, and observational signatures

Science.gov (United States)

Arzamasskiy, Lev; Zhu, Zhaohuan; Stone, James M.

2018-04-01

The interaction of a satellite with a gaseous disc results in the excitation of spiral density waves, which remove angular momentum from the orbit. In addition, if the orbit is not coplanar with the disc, three-dimensional effects will excite bending and eccentricity waves. We perform three-dimensional hydrodynamic simulations to study nonlinear disc-satellite interaction in inviscid protoplanetary discs for a variety of orbital inclinations from 0° to 180°. It is well known that three-dimensional effects are important even for zero inclination. In this work, we (1) show that for planets with small inclinations (as in the Solar system), effects such as the total torque and migration rate strongly depend on the inclination and are significantly different (about 2.5 times smaller) from the two-dimensional case, (2) give formulae for the migration rate, inclination damping, and precession rate of planets with different inclination angles in disc with different scale heights, and (3) present the observational signatures of a planet on an inclined orbit with respect to the protoplanetary disc. For misaligned planets, we find good agreement with linear theory in the limit of small inclinations, and with dynamical friction estimates for intermediate inclinations. We find that in the latter case, the dynamical friction force is not parallel to the relative planetary velocity. Overall, the derived formulae will be important for studying exoplanets with obliquity.

Heat engine in the three-dimensional spacetime

Energy Technology Data Exchange (ETDEWEB)

Mo, Jie-Xiong [Institute of Theoretical Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China); Department of Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China); Liang, Feng [Department of Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China); Li, Gu-Qiang [Institute of Theoretical Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China); Department of Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China)

2017-03-02

We define a kind of heat engine via three-dimensional charged BTZ black holes. This case is quite subtle and needs to be more careful. The heat flow along the isochores does not equal to zero since the specific heat C{sub V}≠0 and this point completely differs from the cases discussed before whose isochores and adiabats are identical. So one cannot simply apply the paradigm in the former literatures. However, if one introduces a new thermodynamic parameter associated with the renormalization length scale, the above problem can be solved. We obtain the analytical efficiency expression of the three-dimensional charged BTZ black hole heat engine for two different schemes. Moreover, we double check with the exact formula. Our result presents the first specific example for the sound correctness of the exact efficiency formula. We argue that the three-dimensional charged BTZ black hole can be viewed as a toy model for further investigation of holographic heat engine. Furthermore, we compare our result with that of the Carnot cycle and extend the former result to three-dimensional spacetime. In this sense, the result in this paper would be complementary to those obtained in four-dimensional spacetime or ever higher. Last but not the least, the heat engine efficiency discussed in this paper may serve as a criterion to discriminate the two thermodynamic approaches introduced in ref. https://www.doi.org/10.1103/PhysRevD.92.124069 and our result seems to support the approach which introduces a new thermodynamic parameter R=r{sub 0}.

Subjective figure reversal in two- and three-dimensional perceptual space.

Science.gov (United States)

Radilová, J; Radil-Weiss, T

1984-08-01

A permanently illuminated pattern of Mach's truncated pyramid can be perceived according to the experimental instruction given, either as a three-dimensional reversible figure with spontaneously changing convex and concave interpretation (in one experiment), or as a two-dimensional reversible figure-ground pattern (in another experiment). The reversal rate was about twice as slow, without the subjects being aware of it, if it was perceived as a three-dimensional figure compared to the situation when it was perceived as two-dimensional. It may be hypothetized that in the three-dimensional case, the process of perception requires more sequential steps than in the two-dimensional one.

Three-Dimensional Reconstruction of Sandpile Interiors

Science.gov (United States)

Seidler, G. T.

2001-03-01

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

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

Science.gov (United States)

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

2014-02-01

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

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

DEFF Research Database (Denmark)

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

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

Three-dimensional imaging utilizing energy discrimination

International Nuclear Information System (INIS)

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

1990-01-01

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

The diagnostic significance of CT-guided percutaneous transthoracic cutting needle biopsy for pulmonary lesions

International Nuclear Information System (INIS)

Wang Hui; Zhang Fuchen; Ji Hongjian; Chen Liping

2009-01-01

Objective: To evaluate the diagnostic significance of CT-guided percutaneous transthoracic cutting needle biopsy for pulmonary lesions. Methods: The clinical data of CT-guided transthoracic cutting needle biopsy in 436 patients performed in past 10 years were retrospectively analyzed. Of 436 cases with pulmonary lesions, primary lung cancer was confirmed in 341, pulmonary metastasis in 62, non-malignant lesions in 33. The diagnostic accuracy and sensitivity were statistically analyzed. The occurrence of complications was discussed. Results: The diagnostic accuracy rate and sensitivity rate in primary lung cancer group were 94.7% and 94.1% respectively, in pulmonary metastasis group were 58.2% and 51.6% respectively and in non-malignant lesions group were 57.6% and 57.6% respectively. The successful rate of biopsy was 97.9%. The occurrence of complications was 15.6%. Conclusion: CT-guided percutaneous transthoracic cutting needle biopsy is a safe and valuable diagnostic technique with high diagnostic accuracy and less complications. It is very helpful in confirming the diagnosis in the patients with suspected primary pulmonary cancer, although the technical procedures need to be further improved for metastatic and non-malignant lung lesions. (authors)

Three-dimensional charge transport in organic semiconductor single crystals.

Science.gov (United States)

He, Tao; Zhang, Xiying; Jia, Jiong; Li, Yexin; Tao, Xutang

2012-04-24

Three-dimensional charge transport anisotropy in organic semiconductor single crystals - both plates and rods (above and below, respectively, in the figure) - is measured in well-performing organic field-effect transistors for the first time. The results provide an excellent model for molecular design and device preparation that leads to good performance. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Timing of three-dimensional virtual treatment planning of orthognathic surgery: a prospective single-surgeon evaluation on 350 consecutive cases.

Science.gov (United States)

Swennen, Gwen R J

2014-11-01

The purpose of this article is to evaluate the timing for three-dimensional (3D) virtual treatment planning of orthognathic surgery in the daily clinical routine. A total of 350 consecutive patients were included in this study. All patients were scanned following the standardized "Triple CBCT Scan Protocol" in centric relation. Integrated 3D virtual planning and actual surgery were performed by the same surgeon in all patients. Although clinically acceptable, still software improvements especially toward 3D virtual occlusal definition are mandatory to make 3D virtual planning of orthognathic surgery less time-consuming and more user-friendly to the clinician. Copyright © 2014 Elsevier Inc. All rights reserved.

Three dimensional analysis of laterally loaded piles

International Nuclear Information System (INIS)

Yilmaz, C.

1987-01-01

In this study static analysis of laterally loaded pile is studied by the three models. The first model is the beam on discrete elastic springs. This model is analyzed using a flexibility method. The second model is the beam on a two-parameter elastic foundation. This model is analyzed using the linear finite element method. The third model is the finite element model, using the three-dimensional iso-parametric parabolic brick element. Three-dimensional pile group analysis is also performed using elastic constants of single pile obtained by any one of the above analyses. The main objective is to develop computer programs for each model related to single piles and to group analysis. Then, the deflections, rotations, moments, shears, stresses and strains of the single pile are obtained at any arbitrary point. Comparison is made between each model and with other studies such as Poulos 1971, Desai and Appel 1976. In addition, to provide a benchmark of three-dimensional finite element analysis, the Boussinesq problem is analyzed. (orig.)

Three-dimensional seismic analysis for spent fuel storage rack

International Nuclear Information System (INIS)

Lee, Gyu Mahn; Kim, Kang Soo; Park, Keun Bae; Park, Jong Kyun

1998-01-01

Time history analysis is usually performed to characterize the nonlinear seismic behavior of a spent fuel storage rack (SFSR). In the past, the seismic analyses of the SFSR were performed with two-dimensional planar models, which could not account for torsional response and simultaneous multi-directional seismic input. In this study, three-dimensional seismic analysis methodology is developed for the single SFSR using the ANSY code. The 3-D model can be used to determine the nonlinear behavior of the rack, i.e., sliding, uplifting, and impact evaluation between the fuel assembly and rack, and rack and the pool wall. This paper also reviews the 3-D modeling of the SFSR and the adequacy of the ANSYS for the seismic analysis. As a result of the adequacy study, the method of ANSYS transient analysis with acceleration time history is suitable for the seismic analysis of highly nonlinear structure such as an SFSR but it isn't appropriate to use displacement time history of seismic input. (author)

Three-dimensional attached viscous flow basic principles and theoretical foundations

CERN Document Server

Hirschel, Ernst Heinrich; Kordulla, Wilhelm

2014-01-01

Viscous flow is usually treated in the frame of boundary-layer theory and as a two-dimensional flow. At best, books on boundary layers provide the describing equations for three-dimensional boundary layers, and solutions only for certain special cases.   This book presents the basic principles and theoretical foundations of three-dimensional attached viscous flows as they apply to aircraft of all kinds. Though the primary flight speed range is that of civil air transport vehicles, flows past other flying vehicles up to hypersonic speeds are also considered. Emphasis is put on general three-dimensional attached viscous flows and not on three-dimensional boundary layers, as this wider scope is necessary in view of the theoretical and practical problems that have to be overcome in practice.   The specific topics covered include weak, strong, and global interaction; the locality principle; properties of three-dimensional viscous flows; thermal surface effects; characteristic properties; wall compatibility con...

A GPU-based calculation using the three-dimensional FDTD method for electromagnetic field analysis.

Science.gov (United States)

Nagaoka, Tomoaki; Watanabe, Soichi

2010-01-01

Numerical simulations with the numerical human model using the finite-difference time domain (FDTD) method have recently been performed frequently in a number of fields in biomedical engineering. However, the FDTD calculation runs too slowly. We focus, therefore, on general purpose programming on the graphics processing unit (GPGPU). The three-dimensional FDTD method was implemented on the GPU using Compute Unified Device Architecture (CUDA). In this study, we used the NVIDIA Tesla C1060 as a GPGPU board. The performance of the GPU is evaluated in comparison with the performance of a conventional CPU and a vector supercomputer. The results indicate that three-dimensional FDTD calculations using a GPU can significantly reduce run time in comparison with that using a conventional CPU, even a native GPU implementation of the three-dimensional FDTD method, while the GPU/CPU speed ratio varies with the calculation domain and thread block size.

Static and dynamic properties of three-dimensional dot-type magnonic crystals

International Nuclear Information System (INIS)

Maksymov, Artur; Spinu, Leonard

2016-01-01

The static and dynamic magnetization of three-dimensional magnonic metamaterials has been investigated. By numerical means it was analyzed the impact of space dimensionality on the properties of magnonic crystal with unit cell consisting of four dots. It is find out the possibility of multi-vortex core formation which is related to the increasing of the crystal height by three-dimensional periodicity of single crystal layer. Additionally is provided the analysis of ferromagnetic resonance phenomenon for two-dimensional and three-dimensional structures. For the unsaturated magnetization of three-dimensional crystal the several pronounced resonance frequencies were detected.

Static and dynamic properties of three-dimensional dot-type magnonic crystals

Energy Technology Data Exchange (ETDEWEB)

Maksymov, Artur, E-mail: maxyartur@gmail.com [Advanced Materials Research Institute, University of New Orleans, LA 70148 (United States); Department of General Physics, Chernivtsi National University, Chernivtsi 58012 (Ukraine); Spinu, Leonard [Advanced Materials Research Institute, University of New Orleans, LA 70148 (United States); Department of Physics, University of New Orleans, New Orleans, LA 70148 (United States)

2016-04-01

The static and dynamic magnetization of three-dimensional magnonic metamaterials has been investigated. By numerical means it was analyzed the impact of space dimensionality on the properties of magnonic crystal with unit cell consisting of four dots. It is find out the possibility of multi-vortex core formation which is related to the increasing of the crystal height by three-dimensional periodicity of single crystal layer. Additionally is provided the analysis of ferromagnetic resonance phenomenon for two-dimensional and three-dimensional structures. For the unsaturated magnetization of three-dimensional crystal the several pronounced resonance frequencies were detected.

Self-consistent Analysis of Three-dimensional Uniformly Charged Ellipsoid with Zero Emittance

International Nuclear Information System (INIS)

Batygin, Yuri K.

2001-01-01

A self-consistent treatment of a three-dimensional ellipsoid with negligible emittance in time-dependent external field is performed. Envelope equations describing the evolution of an ellipsoid boundary are discussed. For a complete model it is required that the initial particle momenta be a linear function of the coordinates. Numerical example and verification of the problem by a 3-dimensional particle-in-cell simulations are given

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...

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

DEFF Research Database (Denmark)

Thornton, Katsuyo; Poulsen, Henning Friis

2008-01-01

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

New method for solving three-dimensional Schroedinger equation

International Nuclear Information System (INIS)

Melezhik, V.S.

1990-01-01

The method derived recently for solving a multidimensional scattering problem is applied to a three-dimensional Schroedinger equation. As compared with direct three-dimensional calculations of finite elements and finite differences, this approach gives sufficiently accurate upper and lower approximations to the helium-atom binding energy, which demonstrates its efficiency. 15 refs.; 1 fig.; 2 tabs

Recursive solutions for multi-group neutron kinetics diffusion equations in homogeneous three-dimensional rectangular domains with time dependent perturbations

Energy Technology Data Exchange (ETDEWEB)

Petersen, Claudio Z. [Universidade Federal de Pelotas, Capao do Leao (Brazil). Programa de Pos Graduacao em Modelagem Matematica; Bodmann, Bardo E.J.; Vilhena, Marco T. [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil). Programa de Pos-graduacao em Engenharia Mecanica; Barros, Ricardo C. [Universidade do Estado do Rio de Janeiro, Nova Friburgo, RJ (Brazil). Inst. Politecnico

2014-12-15

In the present work we solve in analytical representation the three dimensional neutron kinetic diffusion problem in rectangular Cartesian geometry for homogeneous and bounded domains for any number of energy groups and precursor concentrations. The solution in analytical representation is constructed using a hierarchical procedure, i.e. the original problem is reduced to a problem previously solved by the authors making use of a combination of the spectral method and a recursive decomposition approach. Time dependent absorption cross sections of the thermal energy group are considered with step, ramp and Chebyshev polynomial variations. For these three cases, we present numerical results and discuss convergence properties and compare our results to those available in the literature.

Three-dimensional modeler for animated images display system

International Nuclear Information System (INIS)

Boubekeur, Rania

1987-01-01

The mv3d software allows the modeling and display of three dimensional objects in interpretative mode with animation possibility in real time. This system is intended for a graphical extension of a FORTH interpreter (implemented by CEA/IRDI/D.LETI/DEIN) in order to control a specific hardware (3.D card designed and implemented by DEIN) allowing the generation of three dimensional objects. The object description is carried out with a specific graphical language integrated in the FORTH interpreter. Objects are modeled using elementary solids called basic forms (cube, cone, cylinder...) assembled with classical geometric transformations (rotation, translation and scaling). These basic forms are approximated by plane polygonal facets further divided in triangles. Coordinates of the summits of triangles constitute the geometrical data. These are sent to the 3.D. card for processing and display. Performed processing are: geometrical transformations on display, hidden surface elimination, shading and clipping. The mv3d software is not an entire modeler but a simple, modular and extensible tool, to which other specific functions may be easily added such as: robots motion, collisions... (author) [fr

Use of real time three-dimensional transesophageal echocardiography in intracardiac catheter based interventions.

Science.gov (United States)

Perk, Gila; Lang, Roberto M; Garcia-Fernandez, Miguel Angel; Lodato, Joe; Sugeng, Lissa; Lopez, John; Knight, Brad P; Messika-Zeitoun, David; Shah, Sanjiv; Slater, James; Brochet, Eric; Varkey, Mathew; Hijazi, Ziyad; Marino, Nino; Ruiz, Carlos; Kronzon, Itzhak

2009-08-01

Real-time three-dimensional (RT3D) echocardiography is a recently developed technique that is being increasingly used in echocardiography laboratories. Over the past several years, improvements in transducer technologies have allowed development of a full matrix-array transducer that allows acquisition of pyramidal-shaped data sets. These data sets can be processed online and offline to allow accurate evaluation of cardiac structures, volumes, and mass. More recently, a transesophageal transducer with RT3D capabilities has been developed. This allows acquisition of high-quality RT3D images on transesophageal echocardiography (TEE). Percutaneous catheter-based procedures have gained growing acceptance in the cardiac procedural armamentarium. Advances in technology and technical skills allow increasingly complex procedures to be performed using a catheter-based approach, thus obviating the need for open-heart surgery. The authors used RT3D TEE to guide 72 catheter-based cardiac interventions. The procedures included the occlusion of atrial septal defects or patent foramen ovales (n=25), percutaneous mitral valve repair (e-valve clipping; n=3), mitral balloon valvuloplasty for mitral stenosis (n=10), left atrial appendage obliteration (n=11), left atrial or pulmonary vein ablation for atrial fibrillation (n=5), percutaneous closures of prosthetic valve dehiscence (n=10), percutaneous aortic valve replacement (n=6), and percutaneous closures of ventricular septal defects (n=2). In this review, the authors describe their experience with this technique, the added value over multiplanar two-dimensional TEE, and the pitfalls that were encountered. The main advantages found for the use RT3D TEE during catheter-based interventions were (1) the ability to visualize the entire lengths of intracardiac catheters, including the tips of all catheters and the balloons or devices they carry, along with a clear depiction of their positions in relation to other cardiac structures, and

Terahertz computed tomography in three-dimensional using a pyroelectric array detector

Science.gov (United States)

Li, Bin; Wang, Dayong; Zhou, Xun; Rong, Lu; Huang, Haochong; Wan, Min; Wang, Yunxin

2017-05-01

Terahertz frequency range spans from 0.1 to 10 THz. Terahertz radiation can penetrate nonpolar materials and nonmetallic materials, such as plastics, wood, and clothes. Then the feature makes the terahertz imaging have important research value. Terahertz computed tomography makes use of the penetrability of terahertz radiation and obtains three-dimensional object projection data. In the paper, continuous-wave terahertz computed tomography with a pyroelectric array detectoris presented. Compared with scanning terahertz computed tomography, a pyroelectric array detector can obtain a large number of projection data in a short time, as the acquisition mode of the array pyroelectric detector omit the projection process on the vertical and horizontal direction. With the two-dimensional cross-sectional images of the object are obtained by the filtered back projection algorithm. The two side distance of the straw wall account for 80 pixels, so it multiplied by the pixel size is equal to the diameter of the straw about 6.4 mm. Compared with the actual diameter of the straw, the relative error is 6%. In order to reconstruct the three-dimensional internal structure image of the straw, the y direction range from 70 to 150 are selected on the array pyroelectric detector and are reconstructed by the filtered back projection algorithm. As the pixel size is 80 μm, the height of three-dimensional internal structure image of the straw is 6.48 mm. The presented system can rapidly reconstruct the three-dimensional object by using a pyroelectric array detector and explores the feasibility of on non-destructive evaluation and security testing.

Resonance fluorescence based two- and three-dimensional atom localization

Science.gov (United States)

Wahab, Abdul; Rahmatullah; Qamar, Sajid

2016-06-01

Two- and three-dimensional atom localization in a two-level atom-field system via resonance fluorescence is suggested. For the two-dimensional localization, the atom interacts with two orthogonal standing-wave fields, whereas for the three-dimensional atom localization, the atom interacts with three orthogonal standing-wave fields. The effect of the detuning and phase shifts associated with the corresponding standing-wave fields is investigated. A precision enhancement in position measurement of the single atom can be noticed via the control of the detuning and phase shifts.

Dynamic model of organic pollutant degradation in three dimensional packed bed electrode reactor.

Science.gov (United States)

Pang, Tianting; Wang, Yan; Yang, Hui; Wang, Tianlei; Cai, Wangfeng

2018-04-21

A dynamic model of semi-batch three-dimensional electrode reactor was established based on the limiting current density, Faraday's law, mass balance and a series of assumptions. Semi-batch experiments of phenol degradation were carried out in a three-dimensional electrode reactor packed with activated carbon under different conditions to verify the model. The factors such as the current density, the electrolyte concentration, the initial pH value, the flow rate of organic and the initial organic concentration were examined to know about the pollutant degradation in the three-dimensional electrode reactor. The various concentrations and logarithm of concentration of phenol with time were compared with the dynamic model. It was shown that the calculated data were in good agreement with experimental data in most cases. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-09-01

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

Three-dimensional imagery by encoding sources of X rays

International Nuclear Information System (INIS)

Magnin, Isabelle

1987-01-01

This research thesis addresses the theoretical and practical study of X ray coded sources, and thus notably aims at exploring whether it would be possible to transform a standard digital radiography apparatus (as those operated in radiology hospital departments) into a low cost three-dimensional imagery system. The author first recalls the principle of conventional tomography and improvement attempts, and describes imagery techniques based on the use of encoding openings and source encoding. She reports the modelling of an imagery system based on encoded sources of X ray, and addresses the original notion of three-dimensional response for such a system. The author then addresses the reconstruction method by considering the reconstruction of a plane object, of a multi-plane object, and of real three-dimensional object. The frequency properties and the tomographic capacities of various types of source codes are analysed. She describes a prototype tomography apparatus, and presents and discusses three-dimensional actual phantom reconstructions. She finally introduces a new principle of dynamic three-dimensional radiography which implements an acquisition technique by 'gating code'. The acquisition principle should allow the reconstruction of volumes animated by periodic deformations, such as the heart for example [fr

Transthoracic CT-guided biopsy with multiplanar reconstruction image improves diagnostic accuracy of solitary pulmonary nodules

International Nuclear Information System (INIS)

Ohno, Yoshiharu; Hatabu, Hiroto; Takenaka, Daisuke; Imai, Masatake; Ohbayashi, Chiho; Sugimura, Kazuro

2004-01-01

Objective: To evaluate the utility of multiplanar reconstruction (MPR) image for CT-guided biopsy and determine factors of influencing diagnostic accuracy and the pneumothorax rate. Materials and methods: 390 patients with 396 pulmonary nodules underwent transthoracic CT-guided aspiration biopsy (TNAB) and transthoracic CT-guided cutting needle core biopsy (TCNB) as follows: 250 solitary pulmonary nodules (SPNs) underwent conventional CT-guided biopsy (conventional method), 81 underwent CT-fluoroscopic biopsy (CT-fluoroscopic method) and 65 underwent conventional CT-guided biopsy in combination with MPR image (MPR method). Success rate, overall diagnostic accuracy, pneumothorax rate and total procedure time were compared in each method. Factors affecting diagnostic accuracy and pneumothorax rate of CT-guided biopsy were statistically evaluated. Results: Success rates (TNAB: 100.0%, TCNB: 100.0%) and overall diagnostic accuracies (TNAB: 96.9%, TCNB: 97.0%) of MPR were significantly higher than those using the conventional method (TNAB: 87.6 and 82.4%, TCNB: 86.3 and 81.3%) (P<0.05). Diagnostic accuracy were influenced by biopsy method, lesion size, and needle path length (P<0.05). Pneumothorax rate was influenced by pathological diagnostic method, lesion size, number of punctures and FEV1.0% (P<0.05). Conclusion: The use of MPR for CT-guided lung biopsy is useful for improving diagnostic accuracy with no significant increase in pneumothorax rate or total procedure time

Three-dimensional oscillator and Coulomb systems reduced from Kaehler spaces

International Nuclear Information System (INIS)

Nersessian, Armen; Yeranyan, Armen

2004-01-01

We define the oscillator and Coulomb systems on four-dimensional spaces with U(2)-invariant Kaehler metric and perform their Hamiltonian reduction to the three-dimensional oscillator and Coulomb systems specified by the presence of Dirac monopoles. We find the Kaehler spaces with conic singularity, where the oscillator and Coulomb systems on three-dimensional sphere and two-sheet hyperboloid originate. Then we construct the superintegrable oscillator system on three-dimensional sphere and hyperboloid, coupled to a monopole, and find their four-dimensional origins. In the latter case the metric of configuration space is a non-Kaehler one. Finally, we extend these results to the family of Kaehler spaces with conic singularities

From Two- to Three-Dimensional Structures of a Supertetrahedral Boran Using Density Functional Calculations.

Science.gov (United States)

Getmanskii, Iliya V; Minyaev, Ruslan M; Steglenko, Dmitrii V; Koval, Vitaliy V; Zaitsev, Stanislav A; Minkin, Vladimir I

2017-08-14

With help of the DFT calculations and imposing of periodic boundary conditions the geometrical and electronic structures were investigated of two- and three-dimensional boron systems designed on the basis of graphane and diamond lattices in which carbons were replaced with boron tetrahedrons. The consequent studies of two- and three-layer systems resulted in the construction of a three-dimensional supertetrahedral borane crystal structure. The two-dimensional supertetrahedral borane structures with less than seven layers are dynamically unstable. At the same time the three-dimensional superborane systems were found to be dynamically stable. Lack of the forbidden electronic zone for the studied boron systems testifies that these structures can behave as good conductors. The low density of the supertetrahedral borane crystal structures (0.9 g cm -3 ) is close to that of water, which offers the perspective for their application as aerospace and cosmic materials. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Supersymmetric quantum mechanics in three-dimensional space, 1

International Nuclear Information System (INIS)

Ui, Haruo

1984-01-01

As a direct generalization of the model of supersymmetric quantum mechanics by Witten, which describes the motion of a spin one-half particle in the one-dimensional space, we construct a model of the supersymmetric quantum mechanics in the three-dimensional space, which describes the motion of a spin one-half particle in central and spin-orbit potentials in the context of the nonrelativistic quantum mechanics. With the simplest choice of the (super) potential, this model is shown to reduce to the model of the harmonic oscillator plus constant spin-orbit potential of unit strength of both positive and negative signs, which was studied in detail in our recent paper in connection with ''accidental degeneracy'' as well as the ''graded groups''. This simplest model is discussed in some detail as an example of the three-dimensional supersymmetric quantum mechanical system, where the supersymmetry is an exact symmetry of the system. More general choice of a polynomial superpotential is also discussed. It is shown that the supersymmetry cannot be spontaneously broken for any polynomial superpotential in our three-dimensional model; this result is contrasted to the corresponding one in the one-dimensional model. (author)

Three-dimensional flow measurements induced from serpentine plasma actuators in quiescent air

International Nuclear Information System (INIS)

Durscher, R J; Roy, S

2012-01-01

This paper presents three-dimensional flow measurements performed on a dielectric barrier discharge (DBD) actuator with the electrodes in a serpentine design. Such a configuration induces a local pinching and a local spreading of the fluid as one follows along the span of the actuator. In this work two different variations on the serpentine configuration are evaluated: one constructed from patterned circular arcs and one from patterned rectangles. The influence of applied voltage is studied for the former case. To quantify these effects stereo particle image velocimetry (PIV) is used to generate time averaged, spatially resolved measurements of the detailed flow structure. The three components of the velocity vector are measured along spanwise and streamwise cuts. These slices are then reconstructed to provide a three-dimensional view of the induced flow field. The results for the induced flow fields are also compared with stereo-PIV measurements made on a standard linear DBD actuator. A truly three-dimensional induced flow field was observed as a result of the serpentine configuration. These designs could be beneficial for rapid mixing of the local fluid. (paper)

Recognition method for three-dimensional image in dismantling of nuclear power plant

International Nuclear Information System (INIS)

Chino, Koichi.

1993-01-01

The present invention constitutes three-dimensional images of structures, in a short period of time, at a place where a man can hardly access upon dismantling of a large scaled nuclear power facilities contaminated by radioactive materials. That is, a television set is disposed on a movable rack. Images of structures as an objective are taken and compared with previously inputted data, to constitute rough images. The television set is moved to an evaluated position where a view angle changes sufficiently based on the rough images. Images of the objective structures are taken at the position after movement. A plurality of thus obtained images and previously stored information concerning the structures are compared, examined and corrected if required, and the three-dimensional images of the objective structures are recognized. According to the present invention, the three-dimensional images of the structures in the nuclear power plant can be recognized automatically at high accuracy by one television set. (I.S.)

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...... to a dressed state picture, where the light modes are solutions to the diffraction problem, and develop a perturbative expansion in the fluctuations. The fluctuations are due to quantum fluctuations as well as the random positions of the atoms. In this perturbative expansion we show how the quantum...... 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....

NMR experiments on a three-dimensional vibrofluidized granular medium

Science.gov (United States)

Huan, Chao; Yang, Xiaoyu; Candela, D.; Mair, R. W.; Walsworth, R. L.

2004-04-01

A three-dimensional granular system fluidized by vertical container vibrations was studied using pulsed field gradient NMR coupled with one-dimensional magnetic resonance imaging. The system consisted of mustard seeds vibrated vertically at 50 Hz, and the number of layers Nl⩽4 was sufficiently low to achieve a nearly time-independent granular fluid. Using NMR, the vertical profiles of density and granular temperature were directly measured, along with the distributions of vertical and horizontal grain velocities. The velocity distributions showed modest deviations from Maxwell-Boltzmann statistics, except for the vertical velocity distribution near the sample bottom, which was highly skewed and non-Gaussian. Data taken for three values of Nl and two dimensionless accelerations Γ=15,18 were fitted to a hydrodynamic theory, which successfully models the density and temperature profiles away from the vibrating container bottom. A temperature inversion near the free upper surface is observed, in agreement with predictions based on the hydrodynamic parameter μ which is nonzero only in inelastic systems.

Three dimensional contact/impact methodology

International Nuclear Information System (INIS)

Kulak, R.F.

1987-01-01

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

Dimensional Stability of Two Polyvinyl Siloxane Impression Materials in Different Time Intervals

Directory of Open Access Journals (Sweden)

Aalaei Sh

2015-12-01

Full Text Available Statement of the Problem: Dental prosthesis is usually made indirectly; there- fore dimensional stability of the impression material is very important. Every few years, new impression materials with different manufacturers’ claims regarding their better properties are introduced to the dental markets which require more research to evaluate their true dimensional changes. Objectives: The aim of this study was to evaluate dimensional stability of additional silicone impression material (Panasil® and Affinis® in different time intervals. Materials and Methods: In this experimental study, using two additional silicones (Panasil® and Affinis®, we made sixty impressions of standard die in similar conditions of 23 °C and 59% relative humidity by a special tray. The die included three horizontal and two vertical lines that were parallel. The vertical line crossed the horizontal ones at a point that served as reference for measurement. All impressions were poured with high strength dental stone. The dimensions were measured by stereo-microscope by two examiners in three interval storage times (1, 24 and 168 hours.The data were statistically analyzed using t-test and ANOVA. Results: All of the stone casts were larger than the standard die. Dimensional changes of Panasil and Affinis were 0.07%, 0.24%, 0.27% and 0.02%, 0.07%, 0.16% after 1, 24 and 168 hours, respectively. Dimensional change for two impression materials wasn’t significant in the interval time, expect for Panasil after one week (p = 0.004. Conclusions: According to the limitations of this study, Affinis impressions were dimensionally more stable than Panasil ones, but it was not significant. Dimensional change of Panasil impression showed a statistically significant difference after one week. Dimensional changes of both impression materials were based on ADA standard limitation in all time intervals (< 0.5%; therefore, dimensional stability of this impression was accepted at least

Transient analysis of cutoff waveguide antenna in three-dimensional space

International Nuclear Information System (INIS)

Kashiwa, Tatsuya; Yoshida, Norinobu; Fukai, Ichiro

1986-01-01

Recently, the exciting system for electric power heating as seen in nuclear fusion plasma heating and medical purpose has been actively studied and developed. Since such system treats basically a neighborhood field, various problems unlike conventional exciting system for communication arise. In such situation, the structure having the waveguides of simple and robust construction as the main body has been proposed. In this exciting system including the condition of media, the complex distribution of a neighborhood field based on a three-dimensional structure exerts an important effect on the characteristics. Especially in large power excitation, the higher mode of relatively small power distribution cannot be neglected. Besides, also a transient field distribution exerts an important effect on the characteristics, and the time response analysis is required. In this analysis, by the three-dimensional time response analysis method using Bergeron method, the unified analysis of the total system comprising a cutoff waveguide, a coaxial exciting part and a heating region was carried out for determining a radiation neighborhood electromagnetic field by a cutoff waveguide antenna. (Kako, I.)

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 echocardiography

International Nuclear Information System (INIS)

Buck, Thomas

2011-01-01

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

Stochastic self-propagating star formation in three-dimensional disk galaxy simulations

International Nuclear Information System (INIS)

Statler, T.; Comins, N.; Smith, B.F.

1983-01-01

Stochastic self-propagating star formation (SSPSF) is a process of forming new stars through the compression of the interstellar medium by supernova shock waves. Coupling this activity with galactic differential rotation produces spiral structure in two-dimensional disk galaxy simulations. In this paper the first results of a three-dimensional SSPSF simulation of disk galaxies are reported. Our model generates less impressive spirals than do the two-dimensional simulations. Although some spirals do appear in equilibrium, more frequently we observe spirals as non-equilibrium states of the models: as the spiral arms evolve, they widen until the spiral structure is no longer discernible. The two free parameters that we vary in this study are the probability of star formation due to a recent, nearby explosion, and the relaxation time for the interstellar medium to return to a condition of maximum star formation after it has been cleared out by an explosion and subsequent star formation. We find that equilibrium spiral structure is formed over a much smaller range of these parameters in our three-dimensional SSPSF models than in similar two-dimensional models. We discuss possible reasons for these results as well as improvements on the model which are being explored

Severe Hiatal Hernia as a Cause of Failure to Thrive Discovered by Transthoracic Echocardiogram

Directory of Open Access Journals (Sweden)

Clint J. Moore

2016-01-01

Full Text Available A newborn infant with failure to thrive presented for murmur evaluation on day of life three due to a harsh 3/6 murmur. During the evaluation, a retrocardiac fluid filled mass was seen by transthoracic echocardiogram. The infant was also found to have a ventricular septal defect and partial anomalous pulmonary venous return. Eventually, a large hiatal hernia was diagnosed on subsequent imaging. The infant ultimately underwent surgical repair of the hiatal hernia at a tertiary care facility. Hiatal hernias have been noted as incidental extracardiac findings in adults, but no previous literature has documented hiatal hernias as incidental findings in the pediatric population.

Severe Hiatal Hernia as a Cause of Failure to Thrive Discovered by Transthoracic Echocardiogram

Science.gov (United States)

Moore, Clint J.; Conley, Devan A.; Berry-Cabán, Cristóbal S.

2016-01-01

A newborn infant with failure to thrive presented for murmur evaluation on day of life three due to a harsh 3/6 murmur. During the evaluation, a retrocardiac fluid filled mass was seen by transthoracic echocardiogram. The infant was also found to have a ventricular septal defect and partial anomalous pulmonary venous return. Eventually, a large hiatal hernia was diagnosed on subsequent imaging. The infant ultimately underwent surgical repair of the hiatal hernia at a tertiary care facility. Hiatal hernias have been noted as incidental extracardiac findings in adults, but no previous literature has documented hiatal hernias as incidental findings in the pediatric population. PMID:27895952

Analysis of contact stiffness in ultrasound atomic force microscopy: three-dimensional time-dependent ultrasound modeling

International Nuclear Information System (INIS)

Piras, Daniele; Sadeghian, Hamed

2017-01-01

Ultrasound atomic force microscopy (US-AFM) has been used for subsurface imaging of nanostructures. The contact stiffness variations have been suggested as the origin of the image contrast. Therefore, to analyze the image contrast, the local changes in the contact stiffness due to the presence of subsurface features should be calculated. So far, only static simulations have been conducted to analyze the local changes in the contact stiffness and, consequently, the contrast in US-AFM. Such a static approach does not fully represent the real US-AFM experiment, where an ultrasound wave is launched either into the sample or at the tip, which modulates the contact stiffness. This is a time-dependent nonlinear dynamic problem rather than a static and stationary one. This paper presents dynamic 3D ultrasound analysis of contact stiffness in US-AFM (in contrast to static analysis) to realistically predict the changes in contact stiffness and thus the changes in the subsurface image contrast. The modulation frequency also influences the contact stiffness variations and, thus, the image contrast. The three-dimensional time-dependent ultrasound analysis will greatly aid in the contrast optimization of subsurface nano imaging with US-AFM. (paper)

The contribution of CT-guided transthoracic lung biopsy to the diagnosis of organising pneumonia.

Science.gov (United States)

Metzger, F; Pernet, D; Manzoni, P; Ranfaing, E; Dalphin, J-C

2010-09-01

Organising pneumonia is a pulmonary disease with variable clinical and radiological features and with many differential diagnoses. Diagnosis is based on histology obtained by either transbronchial or surgical lung biopsy but these techniques have several disadvantages. The aim of this study was to evaluate the diagnostic yield of CT-guided transthoracic lung biopsy in organising pneumonia and to compare it to the usual diagnostic tools. Six cases of organising pneumonia diagnosed with CT-guided lung biopsy are reported and discussed. The role of CT-guided lung biopsy in the diagnosis of organising pneumonia was also reviewed in the literature. CT-guided transthoracic lung biopsies provided a higher rate of adequate samples than transbronchial biopsies (92-100% versus 77-86%). The samples were larger, which reduced the risks of misdiagnosis and increased the diagnostic yield (88-97% versus 26-55% in pulmonary nodules and 42-100% versus 66-75% in diffuse pulmonary disease). Complications were rare and generally not serious. CT-guided transthoracic lung biopsy may be considered in place of transbronchial biopsy in the diagnosis of organising pneumonia. Surgical lung biopsy remains the gold standard method for diagnosis. Copyright © 2010 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Advances in three-dimensional field analysis and evaluation of performance parameters of electrical machines

Science.gov (United States)

Sivasubramaniam, Kiruba

This thesis makes advances in three dimensional finite element analysis of electrical machines and the quantification of their parameters and performance. The principal objectives of the thesis are: (1)the development of a stable and accurate method of nonlinear three-dimensional field computation and application to electrical machinery and devices; and (2)improvement in the accuracy of determination of performance parameters, particularly forces and torque computed from finite elements. Contributions are made in two general areas: a more efficient formulation for three dimensional finite element analysis which saves time and improves accuracy, and new post-processing techniques to calculate flux density values from a given finite element solution. A novel three-dimensional magnetostatic solution based on a modified scalar potential method is implemented. This method has significant advantages over the traditional total scalar, reduced scalar or vector potential methods. The new method is applied to a 3D geometry of an iron core inductor and a permanent magnet motor. The results obtained are compared with those obtained from traditional methods, in terms of accuracy and speed of computation. A technique which has been observed to improve force computation in two dimensional analysis using a local solution of Laplace's equation in the airgap of machines is investigated and a similar method is implemented in the three dimensional analysis of electromagnetic devices. A new integral formulation to improve force calculation from a smoother flux-density profile is also explored and implemented. Comparisons are made and conclusions drawn as to how much improvement is obtained and at what cost. This thesis also demonstrates the use of finite element analysis to analyze torque ripples due to rotor eccentricity in permanent magnet BLDC motors. A new method for analyzing torque harmonics based on data obtained from a time stepping finite element analysis of the machine is

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.

Diffraction limited focusing with controllable arbitrary three-dimensional polarization

International Nuclear Information System (INIS)

Chen, Weibin; Zhan, Qiwen

2010-01-01

We propose a new approach that enables full control over the three-dimensional state of polarization and the field distribution near the focus of a high numerical aperture objective lens. By combining the electric dipole radiation and a vectorial diffraction method, the input field at the pupil plane for generating arbitrary three-dimensionally oriented linear polarization at the focal point with a diffraction limited spot size is found analytically by solving the inverse problem. Arbitrary three-dimensional elliptical polarization can be obtained by introducing a second electric dipole oriented in the orthogonal plane with appropriate amplitude and phase differences

Development of a three-dimensionally movable phantom system for dosimetric verifications

International Nuclear Information System (INIS)

Nakayama, Hiroshi; Mizowaki, Takashi; Narita, Yuichiro; Kawada, Noriyuki; Takahashi, Kunio; Mihara, Kazumasa; Hiraoka, Masahiro

2008-01-01

The authors developed a three-dimensionally movable phantom system (3D movable phantom system) which can reproduce three-dimensional movements to experimentally verify the impact of radiotherapy treatment-related movements on dose distribution. The phantom system consists of three integrated components: a three-dimensional driving mechanism (3D driving mechanism), computer control system, and phantoms for film dosimetry. The 3D driving mechanism is a quintessential part of this system. It is composed of three linear-motion tables (single-axis robots) which are joined orthogonally to each other. This mechanism has a motion range of 100 mm, with a maximum velocity of 200 mm/s in each dimension, and 3D motion ability of arbitrary patterns. These attributes are sufficient to reproduce almost all organ movements. The positional accuracy of this 3D movable phantom system in a state of geostationary is less than 0.1 mm. The maximum error in terms of the absolute position on movement was 0.56 mm. The positional reappearance error on movement was up to 0.23 mm. The observed fluctuation of time was 0.012 s in the cycle of 4.5 s of oscillation. These results suggested that the 3D movable phantom system exhibited a sufficient level of accuracy in terms of geometry and timing to reproduce interfractional organ movement or setup errors in order to assess the influence of these errors on high-precision radiotherapy such as stereotactic irradiation and intensity-modulated radiotherapy. In addition, the authors 3D movable phantom system will also be useful in evaluating the adequacy and efficacy of new treatment techniques such as gating or tracking radiotherapy

Three-dimensional CT imaging of soft-tissue anatomy

International Nuclear Information System (INIS)

Fishman, E.K.; Ney, D.R.; Magid, D.; Kuhlman, J.E.

1988-01-01

Three-dimensional display of computed tomographic data has been limited to skeletal structures. This was in part related to the reconstruction algorithm used, which relied on a binary classification scheme. A new algorithm, volumetric rendering with percentage classification, provides the ability to display three-dimensional images of muscle and soft tissue. A review was conducted of images in 35 cases in which muscle and/or soft tissue were part of the clinical problem. In all cases, individual muscle groups could be clearly identified and discriminated. Branching vessels in the range of 2.3 mm could be identified. Similarly, lymph nodes could be clearly defined. High-resolution three-dimensional images were found to be useful both in providing an increased understanding of complex muscle and soft tissue anatomy and in surgical planning

THREE DIMENSIONAL GRAPHICAL REPRESENTATION OF QUALITY

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Vineet V. Kumar

2014-03-01

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

Time-history simulation of civil architecture earthquake disaster relief- based on the three-dimensional dynamic finite element method

Directory of Open Access Journals (Sweden)

Liu Bing

2014-10-01

Full Text Available Earthquake action is the main external factor which influences long-term safe operation of civil construction, especially of the high-rise building. Applying time-history method to simulate earthquake response process of civil construction foundation surrounding rock is an effective method for the anti-knock study of civil buildings. Therefore, this paper develops a civil building earthquake disaster three-dimensional dynamic finite element numerical simulation system. The system adopts the explicit central difference method. Strengthening characteristics of materials under high strain rate and damage characteristics of surrounding rock under the action of cyclic loading are considered. Then, dynamic constitutive model of rock mass suitable for civil building aseismic analysis is put forward. At the same time, through the earthquake disaster of time-history simulation of Shenzhen Children’s Palace, reliability and practicability of system program is verified in the analysis of practical engineering problems.

Application status of three-dimensional CT reconstruction in hepatobiliary surgery

Directory of Open Access Journals (Sweden)

JIANG Chao

2017-02-01

Full Text Available With the development of imaging technology, three-dimensional CT reconstruction has been widely used in hepatobiliary surgery. Three-dimensional CT reconstruction can divide and reconstruct two-dimensional images into three-dimensional images and clearly show the location of lesion and its relationship with the intrahepatic bile duct system. It has an important value in the preoperative assessment of liver volume, diagnosis and treatment decision-making process, intraoperative precise operation, and postoperative individualized management, and promotes the constant development of hepatobiliary surgery and minimally invasive technology, and therefore, it holds promise for clinical application.

Three-dimensional features on oscillating microbubbles streaming flows

Science.gov (United States)

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.

Sonocubic fine: new three-dimensional ultrasound software to the screening of congenital heart diseases

Directory of Open Access Journals (Sweden)

Edward Araujo Júnior

2014-09-01

Full Text Available Congenital heart disease is the most common fetal congenital malformations; however, the prenatal rate detection still is low. The two-dimensional echocardiography is the "gold standard" exam to screening and diagnosis of congenital heart disease during the prenatal; however, this exam is operator-depending and it is realized only in high risk pregnancies. Spatio-temporal image correlation is a three-dimensional ultrasound software that analyses the fetal heart and your connections in the multiplanar and rendering modes; however, spatio-temporal image correlation too is operator-depending and time-consuming. We presenting a new three-dimensional software named Sonocubic fine to the screening of congenital heart disease. This software applies intelligent navigation technology to spatio-temporal image correlation volume datasets to automatically generate nine fetal echocardiography standard views. Thus, this new software tends to be less operator-depending and time-consuming.

Three-dimensional transition in the wake of a circular cylinder by direct numerical simulation

International Nuclear Information System (INIS)

Kang, S. J.; Mo, J. O.; Lee, Y. H.; Tanahashi, M.; Miyauchi, T.

2001-01-01

Three-dimensional time-dependent flow past a circular cylinder is numerically investigated using direct numerical simulation for Reynolds number 280 and 300. The higher-order finite difference scheme is employed for the spatial distributions along with the second order Adams-Bashforth and the first order backward-Euler time integration. In x-y plane, the convection term is applied by the 5th order upwind scheme and the pressure and viscosity terms are applied by the 4th order central difference. And in spanwise, Navier-Stokes equation is distributed using of spectral method. At Reynolds number 259 the two-dimensional wake becomes linearly unstable to a second branch of modes with wavelength about 1.0 diameters at onset (B-mode). Present results of three-dimensional effects of in wake of a circular cylinder is represented with spanwise and streamwise vorticity contours as Reynolds numbers

Computational hemodynamics of an implanted coronary stent based on three-dimensional cine angiography reconstruction.

Science.gov (United States)

Chen, Mounter C Y; Lu, Po-Chien; Chen, James S Y; Hwang, Ned H C

2005-01-01

Coronary stents are supportive wire meshes that keep narrow coronary arteries patent, reducing the risk of restenosis. Despite the common use of coronary stents, approximately 20-35% of them fail due to restenosis. Flow phenomena adjacent to the stent may contribute to restenosis. Three-dimensional computational fluid dynamics (CFD) and reconstruction based on biplane cine angiography were used to assess coronary geometry and volumetric blood flows. A patient-specific left anterior descending (LAD) artery was reconstructed from single-plane x-ray imaging. With corresponding electrocardiographic signals, images from the same time phase were selected from the angiograms for dynamic three-dimensional reconstruction. The resultant three-dimensional LAD artery at end-diastole was adopted for detailed analysis. Both the geometries and flow fields, based on a computational model from CAE software (ANSYS and CATIA) and full three-dimensional Navier-Stroke equations in the CFD-ACE+ software, respectively, changed dramatically after stent placement. Flow fields showed a complex three-dimensional spiral motion due to arterial tortuosity. The corresponding wall shear stresses, pressure gradient, and flow field all varied significantly after stent placement. Combined angiography and CFD techniques allow more detailed investigation of flow patterns in various segments. The implanted stent(s) may be quantitatively studied from the proposed hemodynamic modeling approach.

Transthoracic ultrasonography for the immunocompromised patient. A pilot project that introduces transthoracic ultrasonography for the follow-up of hematological patients in Romania.

Science.gov (United States)

Frinc, Ioana; Ilies, Petru; Zaharie, Florin; Dima, Delia; Tanase, Alina; Petrov, Ljubomir; Irimie, Alexandru; Berce, Cristian; Lisencu, Cosmin; Berindan-Neagoe, Ioana; Tomuleasa, Ciprian; Bojan, Anca

2017-06-01

In the past decade, there has been significant progress in clinical hematology with the discovery of targeted molecules and thus the achievement of both hematologic and molecular responses. Nevertheless, chemotherapy remains the treatment of choice for many types of hematological malignancies. Aggressive chemotherapy leads to immunosuppression, accompanied by a high rate of infections and an increased rate of treatment-related mortality. Invasive fungal infections as well as more common bacterial and viral infections are frequent in immunocompromised patients as they are difficult to diagnose and treat. Pleuropulmonary infections in immunocompromised patients are diagnosed using clinical examination, imaging and laboratory tests. Many laboratory tests are run for several days before a final result is given and are expensive. Computer tomography is a reliable technique, but it is encumbered by high irradiation and high cost, and can assess lesions larger than 1 cm. Transthoracic ultrasound is a modern method, used in the diagnostic algorithm of pleuropulmonary pathology. It allows the diagnosis of small lesions, can be performed at the patients' bedside, with acceptable costs and no irradiation. A fast, informed and accurate medical decision is essential for a favorable outcome in immunosuppressed patients with an adjacent infection. In the current case series we present the implementation of a new protocol for the follow-up of immunocompromised patients using transthoracic ultrasonography, of great potential use in the clinic.

Transthoracic ultrasonography for the immunocompromised patient. A pilot project that introduces transthoracic ultrasonography for the follow-up of hematological patients in Romania

Directory of Open Access Journals (Sweden)

Frinc Ioana

2017-06-01

Full Text Available In the past decade, there has been significant progress in clinical hematology with the discovery of targeted molecules and thus the achievement of both hematologic and molecular responses. Nevertheless, chemotherapy remains the treatment of choice for many types of hematological malignancies. Aggressive chemotherapy leads to immunosuppression, accompanied by a high rate of infections and an increased rate of treatment-related mortality. Invasive fungal infections as well as more common bacterial and viral infections are frequent in immunocompromised patients as they are difficult to diagnose and treat. Pleuropulmonary infections in immunocompromised patients are diagnosed using clinical examination, imaging and laboratory tests. Many laboratory tests are run for several days before a final result is given and are expensive. Computer tomography is a reliable technique, but it is encumbered by high irradiation and high cost, and can assess lesions larger than 1 cm. Transthoracic ultrasound is a modern method, used in the diagnostic algorithm of pleuropulmonary pathology. It allows the diagnosis of small lesions, can be performed at the patients’ bedside, with acceptable costs and no irradiation. A fast, informed and accurate medical decision is essential for a favorable outcome in immunosuppressed patients with an adjacent infection. In the current case series we present the implementation of a new protocol for the follow-up of immunocompromised patients using transthoracic ultrasonography, of great potential use in the clinic.

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

Science.gov (United States)

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

2016-12-01

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

Three-dimensional image reconstruction from stereo DSA

International Nuclear Information System (INIS)

Sakamoto, Kiyoshi; Kotoura, Noriko; Umehara, Takayoshi; Yamada, Eiji; Inaba, Tomohiro; Itou, Hiroshi

1999-01-01

The technique of interventional radiology has spread rapidly in recent years, and three-dimensional information from blood vessel images is being sought to enhance examinations. Stereo digital subtraction angiography (DSA) and rotational DSA were developed for that purpose. However, it is difficult with stereo DSA to observe the image pair during examination and to obtain positional information on blood vessels. Further, the exposure dose is increased in rotational DSA when many mask images need to be collected, and the patient is required to hold his or her breath for a long duration. We therefore devised a technique to construct three-dimensional blood vessel images by employing geometrical information extracted from stereo DSA images using the right and left images. We used a judgment method based on the correlation coefficient, although we had to extract an equal blood vessel from the right and left images to determine the three-dimensional coordinates of the blood vessel. The reconstructed three-dimensional blood vessels were projected from various angles, again by using a virtual focus, and new images were created. These image groups were displayed as rotational images by the animation display function incorporated in the DSA device. This system can observe blood vessel images of the same phase at a free angle, although the image quality is inferior to that of rotational DSA. In addition, because collection of the mask images is reduced, exposure dose can be decreased. Further, the system offers enhanced safety because no mechanical movement of the imaging system is involved. (author)

Two-dimensional numerical simulation of flow around three-stranded rope

Science.gov (United States)

Wang, Xinxin; Wan, Rong; Huang, Liuyi; Zhao, Fenfang; Sun, Peng

2016-08-01

Three-stranded rope is widely used in fishing gear and mooring system. Results of numerical simulation are presented for flow around a three-stranded rope in uniform flow. The simulation was carried out to study the hydrodynamic characteristics of pressure and velocity fields of steady incompressible laminar and turbulent wakes behind a three-stranded rope. A three-cylinder configuration and single circular cylinder configuration are used to model the three-stranded rope in the two-dimensional simulation. The governing equations, Navier-Stokes equations, are solved by using two-dimensional finite volume method. The turbulence flow is simulated using Standard κ-ɛ model and Shear-Stress Transport κ-ω (SST) model. The drag of the three-cylinder model and single cylinder model is calculated for different Reynolds numbers by using control volume analysis method. The pressure coefficient is also calculated for the turbulent model and laminar model based on the control surface method. From the comparison of the drag coefficient and the pressure of the single cylinder and three-cylinder models, it is found that the drag coefficients of the three-cylinder model are generally 1.3-1.5 times those of the single circular cylinder for different Reynolds numbers. Comparing the numerical results with water tank test data, the results of the three-cylinder model are closer to the experiment results than the single cylinder model results.

ChromAlign: A two-step algorithmic procedure for time alignment of three-dimensional LC-MS chromatographic surfaces.

Science.gov (United States)

Sadygov, Rovshan G; Maroto, Fernando Martin; Hühmer, Andreas F R

2006-12-15

We present an algorithmic approach to align three-dimensional chromatographic surfaces of LC-MS data of complex mixture samples. The approach consists of two steps. In the first step, we prealign chromatographic profiles: two-dimensional projections of chromatographic surfaces. This is accomplished by correlation analysis using fast Fourier transforms. In this step, a temporal offset that maximizes the overlap and dot product between two chromatographic profiles is determined. In the second step, the algorithm generates correlation matrix elements between full mass scans of the reference and sample chromatographic surfaces. The temporal offset from the first step indicates a range of the mass scans that are possibly correlated, then the correlation matrix is calculated only for these mass scans. The correlation matrix carries information on highly correlated scans, but it does not itself determine the scan or time alignment. Alignment is determined as a path in the correlation matrix that maximizes the sum of the correlation matrix elements. The computational complexity of the optimal path generation problem is reduced by the use of dynamic programming. The program produces time-aligned surfaces. The use of the temporal offset from the first step in the second step reduces the computation time for generating the correlation matrix and speeds up the process. The algorithm has been implemented in a program, ChromAlign, developed in C++ language for the .NET2 environment in WINDOWS XP. In this work, we demonstrate the applications of ChromAlign to alignment of LC-MS surfaces of several datasets: a mixture of known proteins, samples from digests of surface proteins of T-cells, and samples prepared from digests of cerebrospinal fluid. ChromAlign accurately aligns the LC-MS surfaces we studied. In these examples, we discuss various aspects of the alignment by ChromAlign, such as constant time axis shifts and warping of chromatographic surfaces.

Transverse oscillation vector flow imaging for transthoracic echocardiography

DEFF Research Database (Denmark)

Bradway, David; Lindskov Hansen, Kristoffer; Nielsen, Michael Bachmann

2015-01-01

-oscillating receive field is described, and results from Field II simulations are presented. Measurements are made using the SARUS experimental ultrasound scanner driving an intercostal phased-array probe. The acquisition sequence was composed of interleaved frames of 68-line B-mode and 17-direction, 32-shot vector......This work presents the development and first results of in vivo transthoracic cardiac imaging using an implementation of Vector Flow Imaging (VFI) via the Transverse Oscillation (TO) method on a phased-array transducer. Optimal selection of the lateral wavelength of the transversely...

Summary of three-dimensional animation creation based on ethnic culture element

Directory of Open Access Journals (Sweden)

Shao Zhaopo

2016-01-01

Full Text Available three-dimensional animation is a product combined by technology and art. It is an artistic ex-pression form combining painting, film & television, digital technology, music, and literature. As an audio and visual art, three-dimensional animation has its own unique culture-loading function, technical aesthetic charac-teristics, and requirements for national art expression. This paper aims to find the method to combine digital technology and national art in combination of three-dimensional animation short film creation, and hopes to clear the road for the cultivation of domestic three-dimensional animation quality project.

Parallelization of a three-dimensional whole core transport code DeCART

Energy Technology Data Exchange (ETDEWEB)

Jin Young, Cho; Han Gyu, Joo; Ha Yong, Kim; Moon-Hee, Chang [Korea Atomic Energy Research Institute, Yuseong-gu, Daejon (Korea, Republic of)

2003-07-01

Parallelization of the DeCART (deterministic core analysis based on ray tracing) code is presented that reduces the computational burden of the tremendous computing time and memory required in three-dimensional whole core transport calculations. The parallelization employs the concept of MPI grouping and the MPI/OpenMP mixed scheme as well. Since most of the computing time and memory are used in MOC (method of characteristics) and the multi-group CMFD (coarse mesh finite difference) calculation in DeCART, variables and subroutines related to these two modules are the primary targets for parallelization. Specifically, the ray tracing module was parallelized using a planar domain decomposition scheme and an angular domain decomposition scheme. The parallel performance of the DeCART code is evaluated by solving a rodded variation of the C5G7MOX three dimensional benchmark problem and a simplified three-dimensional SMART PWR core problem. In C5G7MOX problem with 24 CPUs, a speedup of maximum 21 is obtained on an IBM Regatta machine and 22 on a LINUX Cluster in the MOC kernel, which indicates good parallel performance of the DeCART code. In the simplified SMART problem, the memory requirement of about 11 GBytes in the single processor cases reduces to 940 Mbytes with 24 processors, which means that the DeCART code can now solve large core problems with affordable LINUX clusters. (authors)

Three-dimensional spiral CT during arterial portography: comparison of three rendering techniques.

Science.gov (United States)

Heath, D G; Soyer, P A; Kuszyk, B S; Bliss, D F; Calhoun, P S; Bluemke, D A; Choti, M A; Fishman, E K

1995-07-01

The three most common techniques for three-dimensional reconstruction are surface rendering, maximum-intensity projection (MIP), and volume rendering. Surface-rendering algorithms model objects as collections of geometric primitives that are displayed with surface shading. The MIP algorithm renders an image by selecting the voxel with the maximum intensity signal along a line extended from the viewer's eye through the data volume. Volume-rendering algorithms sum the weighted contributions of all voxels along the line. Each technique has advantages and shortcomings that must be considered during selection of one for a specific clinical problem and during interpretation of the resulting images. With surface rendering, sharp-edged, clear three-dimensional reconstruction can be completed on modest computer systems; however, overlapping structures cannot be visualized and artifacts are a problem. MIP is computationally a fast technique, but it does not allow depiction of overlapping structures, and its images are three-dimensionally ambiguous unless depth cues are provided. Both surface rendering and MIP use less than 10% of the image data. In contrast, volume rendering uses nearly all of the data, allows demonstration of overlapping structures, and engenders few artifacts, but it requires substantially more computer power than the other techniques.

Three-dimensional reconstruction of the pigeon inner ear

NARCIS (Netherlands)

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

2009-01-01

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

Surface representations of two- and three-dimensional fluid flow topology

Science.gov (United States)

Helman, James L.; Hesselink, Lambertus

1990-01-01

We discuss our work using critical point analysis to generate representations of the vector field topology of numerical flow data sets. Critical points are located and characterized in a two-dimensional domain, which may be either a two-dimensional flow field or the tangential velocity field near a three-dimensional body. Tangent curves are then integrated out along the principal directions of certain classes of critical points. The points and curves are linked to form a skeleton representing the two-dimensional vector field topology. When generated from the tangential velocity field near a body in a three-dimensional flow, the skeleton includes the critical points and curves which provide a basis for analyzing the three-dimensional structure of the flow separation. The points along the separation curves in the skeleton are used to start tangent curve integrations to generate surfaces representing the topology of the associated flow separations.

Research on a Rotating Machinery Fault Prognosis Method Using Three-Dimensional Spatial Representations

Directory of Open Access Journals (Sweden)

Xiaoni Dong

2016-01-01

Full Text Available Process models and parameters are two critical steps for fault prognosis in the operation of rotating machinery. Due to the requirement for a short and rapid response, it is important to study robust sensor data representation schemes. However, the conventional holospectrum defined by one-dimensional or two-dimensional methods does not sufficiently present this information in both the frequency and time domains. To supply a complete holospectrum model, a new three-dimensional spatial representation method is proposed. This method integrates improved three-dimensional (3D holospectra and 3D filtered orbits, leading to the integration of radial and axial vibration features in one bearing section. The results from simulation and experimental analysis on a complex compressor show that the proposed method can present the real operational status and clearly reveal early faults, thus demonstrating great potential for condition-based maintenance prediction in industrial machinery.

Three-dimensional magnetophotonic crystals based on artificial opals

Science.gov (United States)

Baryshev, A. V.; Kodama, T.; Nishimura, K.; Uchida, H.; Inoue, M.

2004-06-01

We fabricated and experimentally investigated three-dimensional magnetophotonic crystals (3D MPCs) based on artificial opals. Opal samples with three-dimensional dielectric lattices were impregnated with different types of magnetic material. Magnetic and structural properties of 3D MPCs were studied by field emission scanning electron microscopy, x-ray diffraction analysis, and vibrating sample magnetometer. We have shown that magnetic materials synthesized in voids of opal lattices and the composites obtained have typical magnetic properties.

Three-dimensional magnetophotonic crystals based on artificial opals

International Nuclear Information System (INIS)

Baryshev, A.V.; Kodama, T.; Nishimura, K.; Uchida, H.; Inoue, M.

2004-01-01

We fabricated and experimentally investigated three-dimensional magnetophotonic crystals (3D MPCs) based on artificial opals. Opal samples with three-dimensional dielectric lattices were impregnated with different types of magnetic material. Magnetic and structural properties of 3D MPCs were studied by field emission scanning electron microscopy, x-ray diffraction analysis, and vibrating sample magnetometer. We have shown that magnetic materials synthesized in voids of opal lattices and the composites obtained have typical magnetic properties

Magnetohydrodynamic study of three-dimensional instability of the spontaneous fast magnetic reconnection

International Nuclear Information System (INIS)

Shimizu, T.; Kondoh, K.; Ugai, M.; Shibata, K.

2009-01-01

Three-dimensional instability of the spontaneous fast magnetic reconnection is studied with magnetohydrodynamic (MHD) simulation, where the two-dimensional model of the spontaneous fast magnetic reconnection is destabilized in three dimension. Generally, in two-dimensional magnetic reconnection models, every plasma condition is assumed to be uniform in the sheet current direction. In such two-dimensional MHD simulations, the current sheet destabilized by the initial resistive disturbance can be developed to fast magnetic reconnection by a current driven anomalous resistivity. In this paper, the initial resistive disturbance includes a small amount of fluctuations in the sheet current direction, i.e., along the magnetic neutral line. The other conditions are the same as that of previous two-dimensional MHD studies for fast magnetic reconnection. Accordingly, we may expect that approximately two-dimensional fast magnetic reconnection occurs in the MHD simulation. In fact, the fast magnetic reconnection activated on the first stage of the simulation is two dimensional. However, on the subsequent stages, it spontaneously becomes three dimensional and is strongly localized in the sheet current direction. The resulting three-dimensional fast magnetic reconnection intermittently ejects three-dimensional magnetic loops. Such intermittent ejections of the three-dimensional loops are similar to the intermittent downflows observed in the solar flares. The ejection of the three-dimensional loops seems to be random but, numerically and theoretically, it is shown that the aspect ratio of the ejected loops is limited under a criterion.

Three-dimensional analysis of nonlinear plasma oscillation

International Nuclear Information System (INIS)

Miano, G.

1990-01-01

In an underdense plasma a large-amplitude plasma oscillation may be produced by the beating of two external and colinear electromagnetic waves with a frequency difference approximately equal to the plasma frequency - plasma beat wave (PBW) resonant mechanism. The plasma oscillations are driven by the ponderomotive force arising from the beating of the two imposed electromagnetic waves. In this paper two pump electromagnetic waves with arbitrary transverse profiles have been considered. The plasma is described by using the three dimensinal weakly relativistic fluid equations. The nonlinear plasma oscillation dynamics is studied by using the eulerian description, the averaging and the multiple time scale methods. Unlike the linear theory a strong cross field coupling between longitudinal ans transverse electric field components of the plasma oscillation comes out, resulting in a nonlinear phase change and energy transfer between the two components. Unlike the one-dimensional nonlinear theory, the nonlinear frequency shift is caused by relativistic effects as well as by convective effects and electromagnetic field generated from the three dimensional plasma oscillation. The large amplitude plasma oscillation dynamics produced by a bunched relativistic electron beam with arbitrary transverse profile - plasma wave field (PWF) - or by a high power single frequency short electromagnetic pulse with arbitrary transverse profile - electromagnetic plasma wake field (EPWF) - may be described by means of the present theory. (orig.)

Possibility of estimating three-dimensional mandibular morphology by cephalogram analysis

International Nuclear Information System (INIS)

Kim, S.; Motegi, Etsuko; Kikuchi, Yu; Yamaguchi, Hideharu; Takaki, Takashi; Shibahara, Takahiko

2007-01-01

The purpose of this study was to investigate the possibility of a surmise of three-dimensional mandibular morphology by two-dimensional cephalogram analysis. The materials were three-dimensional CT and cephalogram of 20 female mandibular prognathism patients (average age: 25.20±7.49) before there orthognathic surgery. Mandibular bone volume and sponge bone width were calculated from three-dimensional images constructed from CT images using imaging software (Real Intage, KGT inc.). There was a positive correlation (r=0.72) between mandibular volume value and mandibular ramus width. There was a positive correlation between sponge bone width at the site of the mandibular cuspid and mandibular ramus width and SNB angle (r=0.80), and between sponge bone width at the site of the mandibular molar and symphysis height and mandibular ramus width (r=0.81). It was thought that these results will be useful for a surmise of three-dimensional mandibular morphology by cephalogram analysis. (author)

Three-dimensional interpretation of TEM soundings

Science.gov (United States)

Barsukov, P. O.; Fainberg, E. B.

2013-07-01

We describe the approach to the interpretation of electromagnetic (EM) sounding data which iteratively adjusts the three-dimensional (3D) model of the environment by local one-dimensional (1D) transformations and inversions and reconstructs the geometrical skeleton of the model. The final 3D inversion is carried out with the minimal number of the sought parameters. At each step of the interpretation, the model of the medium is corrected according to the geological information. The practical examples of the suggested method are presented.

High frame rate synthetic aperture vector flow imaging for transthoracic echocardiography

DEFF Research Database (Denmark)

Villagómez Hoyos, Carlos Armando; Stuart, Matthias Bo; Bechsgaard, Thor

2016-01-01

This work presents the first in vivo results of 2-D high frame rate vector velocity imaging for transthoracic cardiac imaging. Measurements are made on a healthy volunteer using the SARUS experimental ultrasound scanner connected to an intercostal phased-array probe. Two parasternal long-axis vie...

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)

Three-dimensional teletherapy treatment planning

International Nuclear Information System (INIS)

Panthaleon van Eck, R.B. van.

1986-01-01

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

Three-dimensional crustal structure for the Mendocino Triple Junction region from local earthquake travel times

Energy Technology Data Exchange (ETDEWEB)

Verdonck, D.; Zandt, G. [Lawrence Livermore National Lab., CA (United States)

1994-12-10

The large-scale, three-dimensional geometry of the Mendocino Triple Junction at Cape Mendocino, California, was investigated by inverting nearly 19,000 P wave arrival times from over 1400 local earthquakes to estimate the three-dimensional velocity structure and hypocentral parameters. A velocity grid 175 km (N-S) by 125 km (E-W) centered near Garberville, California, was constructed with 25 km horizontal and 5 km vertical node spacing. The model was well resolved near Cape Mendocino, where the earthquakes and stations are concentrated. At about 40.6{degrees}N latitude a high-velocity gradient between 6.5 and 7.5 km/s dips gently to the south and east from about 15 km depth near the coast. Relocated hypocenters concentrate below this high gradient which the authors interpret as the oceanic crust of the subducted Gorda Plate. Therefore the depth to the top of the Gorda Plate near Cape Mendocino is interpreted to be {approximately} 15 km. The Gorda Plate appears intact and dipping {approximately}8{degrees} eastward due to subduction and flexing downward 6{degrees}-12{degrees} to the south. Both hypocenters and velocity structure suggest that the southern edge of the plate intersects the coastline at 40.3{degrees}N latitude and maintains a linear trend 15{degrees} south of east to at least 123{degrees}W longitude. The top of a large low-velocity region at 20-30 km depth extends about 50 km N-S and 75 km E-W (roughly between Garberville and Covelo) and is located above and south of the southern edge of the Gorda Plate. The authors interpret this low velocity area to be locally thickened crust (8-10 km) due to either local compressional forces associated with north-south compression caused by the northward impingement of the rigid Pacific Plate or by underthrusting of the base of the accretionary subduction complex at the southern terminous of the Cascadia Subduction Zone. 66 refs., 11 figs., 3 tabs.

Three-dimensional imaging technology offers promise in medicine.

Science.gov (United States)

Karako, Kenji; Wu, Qiong; Gao, Jianjun

2014-04-01

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

Three-Dimensional Computer Simulation as an Important Competence Based Aspect of a Modern Mining Professional

Science.gov (United States)

Aksenova, Olesya; Pachkina, Anna

2017-11-01

The article deals with the problem of necessity of educational process transformation to meet the requirements of modern miming industry; cooperative developing of new educational programs and implementation of educational process taking into account modern manufacturability. The paper proves the idea of introduction into mining professionals learning process studying of three-dimensional models of surface technological complex, ore reserves and underground digging complex as well as creating these models in different graphic editors and working with the information analysis model obtained on the basis of these three-dimensional models. The technological process of manless coal mining at the premises of the mine Polysaevskaya controlled by the information analysis models built on the basis of three-dimensional models of individual objects and technological process as a whole, and at the same time requiring the staff able to use the programs of three-dimensional positioning in the miners and equipment global frame of reference is covered.

SU-E-T-279: Realization of Three-Dimensional Conformal Dose Planning in Prostate Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Li, Z; Jiang, S; Yang, Z [Tianjin University, Tianjin (China); Bai, H; Zhang, X [Seeds biological Pharmacy Ltd, Tianjin (China)

2014-06-01

Purpose: Successful clinical treatment in prostate brachytherapy is largely dependent on the effectiveness of pre-surgery dose planning. Conventional dose planning method could hardly arrive at a satisfy result. In this abstract, a three-dimensional conformal localized dose planning method is put forward to ensure the accuracy and effectiveness of pre-implantation dose planning. Methods: Using Monte Carlo method, the pre-calculated 3-D dose map for single source is obtained. As for multiple seeds dose distribution, the maps are combined linearly to acquire the 3-D distribution. The 3-D dose distribution is exhibited in the form of isodose surface together with reconstructed 3-D organs group real-timely. Then it is possible to observe the dose exposure to target volume and normal tissues intuitively, thus achieving maximum dose irradiation to treatment target and minimum healthy tissues damage. In addition, the exfoliation display of different isodose surfaces can be realized applying multi-values contour extraction algorithm based on voxels. The needles could be displayed in the system by tracking the position of the implanted seeds in real time to conduct block research in optimizing insertion trajectory. Results: This study extends dose planning from two-dimensional to three-dimensional, realizing the three-dimensional conformal irradiation, which could eliminate the limitations of 2-D images and two-dimensional dose planning. A software platform is developed using VC++ and Visualization Toolkit (VTK) to perform dose planning. The 3-D model reconstruction time is within three seconds (on a Intel Core i5 PC). Block research could be conducted to avoid inaccurate insertion into sensitive organs or internal obstructions. Experiments on eight prostate cancer cases prove that this study could make the dose planning results more reasonable. Conclusion: The three-dimensional conformal dose planning method could improve the rationality of dose planning by safely reducing

Three-dimensional detonation cellular structures in rectangular ducts using an improved CESE scheme

KAUST Repository

Shen, Yang

2016-11-01

The three-dimensional premixed H2-O2 detonation propagation in rectangular ducts is simulated using an in-house parallel detonation code based on the second-order space–time conservation element and solution element (CE/SE) scheme. The simulation reproduces three typical cellular structures by setting appropriate cross-sectional size and initial perturbation in square tubes. As the cross-sectional size decreases, critical cellular structures transforming the rectangular or diagonal mode into the spinning mode are obtained and discussed in the perspective of phase variation as well as decreasing of triple point lines. Furthermore, multiple cellular structures are observed through examples with typical aspect ratios. Utilizing the visualization of detailed three-dimensional structures, their formation mechanism is further analyzed.

Three-dimensional detonation cellular structures in rectangular ducts using an improved CESE scheme

KAUST Repository

Shen, Yang; Shen, Hua; Liu, Kai Xin; Chen, Pu; Zhang, De Liang

2016-01-01

The three-dimensional premixed H2-O2 detonation propagation in rectangular ducts is simulated using an in-house parallel detonation code based on the second-order space–time conservation element and solution element (CE/SE) scheme. The simulation reproduces three typical cellular structures by setting appropriate cross-sectional size and initial perturbation in square tubes. As the cross-sectional size decreases, critical cellular structures transforming the rectangular or diagonal mode into the spinning mode are obtained and discussed in the perspective of phase variation as well as decreasing of triple point lines. Furthermore, multiple cellular structures are observed through examples with typical aspect ratios. Utilizing the visualization of detailed three-dimensional structures, their formation mechanism is further analyzed.

Tactical Routing Using Two-Dimensional and Three-Dimensional Views of Terrain

National Research Council Canada - National Science Library

St

2001-01-01

Consoles for military and civilian occupations such as air warfare, command and control, air traffic control, piloting, and meteorological forecasting will be capable of displaying three-dimensional (3-D) perspective views...

Crystallization of a self-assembled three-dimensional DNA nanostructure

International Nuclear Information System (INIS)

Rendek, Kimberly N.; Fromme, Raimund; Grotjohann, Ingo; Fromme, Petra

2013-01-01

In this work, the crystallization of a self-assembling three-dimensional B-DNA nanostructure is described. The powerful and specific molecular-recognition system present in the base-pairing of DNA allows for the design of a plethora of nanostructures. In this work, the crystallization of a self-assembling three-dimensional B-DNA nanostructure is described. The DNA nanostructure consists of six single-stranded oligonucleotides that hybridize to form a three-dimensional tetrahedron of 80 kDa in molecular mass and 20 bp on each edge. Crystals of the tetrahedron have been successfully produced and characterized. These crystals may form the basis for an X-ray structure of the tetrahedron in the future. Nucleotide crystallography poses many challenges, leading to the fact that only 1352 X-ray structures of nucleic acids have been solved compared with more than 80 000 protein structures. In this work, the crystallization optimization for three-dimensional tetrahedra is also described, with the eventual goal of producing nanocrystals to overcome the radiation-damage obstacle by the use of free-electron laser technology in the future

Three-dimensional phase-field simulations of directional solidification

Science.gov (United States)

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 Inverse Transport Solver Based on Compressive Sensing Technique

Science.gov (United States)

Cheng, Yuxiong; Wu, Hongchun; Cao, Liangzhi; Zheng, Youqi

2013-09-01

According to the direct exposure measurements from flash radiographic image, a compressive sensing-based method for three-dimensional inverse transport problem is presented. The linear absorption coefficients and interface locations of objects are reconstructed directly at the same time. It is always very expensive to obtain enough measurements. With limited measurements, compressive sensing sparse reconstruction technique orthogonal matching pursuit is applied to obtain the sparse coefficients by solving an optimization problem. A three-dimensional inverse transport solver is developed based on a compressive sensing-based technique. There are three features in this solver: (1) AutoCAD is employed as a geometry preprocessor due to its powerful capacity in graphic. (2) The forward projection matrix rather than Gauss matrix is constructed by the visualization tool generator. (3) Fourier transform and Daubechies wavelet transform are adopted to convert an underdetermined system to a well-posed system in the algorithm. Simulations are performed and numerical results in pseudo-sine absorption problem, two-cube problem and two-cylinder problem when using compressive sensing-based solver agree well with the reference value.

A method of image improvement in three-dimensional imaging

International Nuclear Information System (INIS)

Suto, Yasuzo; Huang, Tewen; Furuhata, Kentaro; Uchino, Masafumi.

1988-01-01

In general, image interpolation is required when the surface configurations of such structures as bones and organs are three-dimensionally constructed from the multi-sliced images obtained by CT. Image interpolation is a processing method whereby an artificial image is inserted between two adjacent slices to make spatial resolution equal to slice resolution in appearance. Such image interpolation makes it possible to increase the image quality of the constructed three-dimensional image. In our newly-developed algorithm, we have converted the presently and subsequently sliced images to distance images, and generated the interpolation images from these two distance images. As a result, compared with the previous method, three-dimensional images with better image quality have been constructed. (author)

Usefulness Of Three-Dimensional Printing Models for Patients with Stoma Construction

Directory of Open Access Journals (Sweden)

Tetsuro Tominaga

2016-04-01

Full Text Available The use of patient-specific organ models in three-dimensional printing systems could be helpful for the education of patients and medical students. The aim of this study was to clarify whether the use of patient-specific stoma models is helpful for patient education. From January 2014 to September 2014, 5 patients who underwent colorectal surgery and for whom a temporary or permanent stoma had been created were involved in this study. Three-dimensional stoma models and three-dimensional face plates were created. The patients’ ages ranged from 59 to 81 years. Four patients underwent stoma construction because of rectal cancer, and 1 underwent stoma construction because of colon stenosis secondary to recurrent cancer. All patients were educated about their stoma and potential stoma-associated problems using three-dimensional stoma models, and all practiced cutting face plates using three-dimensional face plates. The models were also used during medical staff conferences to discuss current issues. All patients understood their problems and finally became self-reliant. The recent availability of three-dimensional printers has enabled the creation of many organ models, and full-scale stoma and face plate models are now available for patient education on cutting an appropriately individualized face plate. Thus, three-dimensional printers could enable fewer skin problems than are currently associated with daily stomal care.

Three-dimensional ultrasound strain imaging of skeletal muscles

NARCIS (Netherlands)

Gijsbertse, Kaj; Sprengers, Andre M.; Nillesen, Maartje; Hansen, Hendrik H.G.; Verdonschot, Nico; De Korte, Chris L.

2015-01-01

Muscle contraction is characterized by large deformation and translation, which requires a multi-dimensional imaging modality to reveal its behavior. Previous work on ultrasound strain imaging of the muscle contraction was limited to 2D and bi-plane techniques. In this study, a three-dimensional

Topography and extent of pulmonary vagus nerve supply with respect to transthoracic oesophagectomy

NARCIS (Netherlands)

Weijs, Teus J.; Ruurda, Jelle P.; Luyer, Misha D P; Nieuwenhuijzen, Grard A P; Van Hillegersberg, Richard; Bleys, Ronald L A W

2015-01-01

Pulmonary complications are frequently observed after transthoracic oesophagectomy. These complications may be reduced by sparing the vagus nerve branches to the lung. However, current descriptions of the regional anatomy are insufficient. Therefore, we aimed to provide a highly detailed description

Evolution of three-dimensional relativistic current sheets and development of self-generated turbulence

Science.gov (United States)

Takamoto, M.

2018-05-01

In this paper, the temporal evolution of three-dimensional relativistic current sheets in Poynting-dominated plasma is studied for the first time. Over the past few decades, a lot of efforts have been conducted on studying the evolution of current sheets in two-dimensional space, and concluded that sufficiently long current sheets always evolve into the so-called plasmoid chain, which provides a fast reconnection rate independent of its resistivity. However, it is suspected that plasmoid chain can exist only in the case of two-dimensional approximation, and would show transition to turbulence in three-dimensional space. We performed three-dimensional numerical simulation of relativistic current sheet using resistive relativistic magnetohydrodynamic approximation. The results showed that the three-dimensional current sheets evolve not into plasmoid chain but turbulence. The resulting reconnection rate is 0.004, which is much smaller than that of plasmoid chain. The energy conversion from magnetic field to kinetic energy of turbulence is just 0.01 per cent, which is much smaller than typical non-relativistic cases. Using the energy principle, we also showed that the plasmoid is always unstable for a displacement in the opposite direction to its acceleration, probably interchange-type instability, and this always results in seeds of turbulence behind the plasmoids. Finally, the temperature distribution along the sheet is discussed, and it is found that the sheet is less active than plasmoid chain. Our finding can be applied for many high-energy astrophysical phenomena, and can provide a basic model of the general current sheet in Poynting-dominated plasma.

Exact solutions in three-dimensional gravity

CERN Document Server

Garcia-Diaz, Alberto A

2017-01-01

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

Three-dimensional, two-species magnetohydrodynamic studies of the early time behaviors of the Combined Release and Radiation Effects Satellite G2 barium release

International Nuclear Information System (INIS)

Xie, Lianghai; Li, Lei; Wang, Jingdong; Zhang, Yiteng

2014-01-01

We present a three-dimensional, two-species (Ba + and H + ) MHD model to study the early time behaviors of a barium release at about 1 R E like Combined Release and Radiation Effects Satellite G2, with emphasis placed on the three-dimensional evolution of the barium cloud and its effects on the ambient plasma environment. We find that the perturbations caused by the cloud are the combined results of the initial injection, the radial expansion, and the diamagnetic effect and propagate as fast MHD waves in the magnetosphere. In return, the transverse expansion and the cross-B motion of barium ions are constrained by the magnetic force, which lead to a field-aligned striation of ions and the decoupling of these ions from the neutrals. Our simulation shows the formation and collapse of the diamagnetic cavity in the barium cloud. The estimated time scale for the cavity evolution might be much shorter if photoionization time scale and field aligned expansion of barium ions are considered. In addition, our two species MHD simulation also finds the snowplow effect resulting from the momentum coupling between barium ions and background H + , which creates density hole and bumps in the background H + when barium ions expanding along the magnetic field lines

[Clinical effect of three dimensional human body scanning system BurnCalc in the evaluation of burn wound area].

Science.gov (United States)

Lu, J; Wang, L; Zhang, Y C; Tang, H T; Xia, Z F

2017-10-20

Objective: To validate the clinical effect of three dimensional human body scanning system BurnCalc developed by our research team in the evaluation of burn wound area. Methods: A total of 48 burn patients treated in the outpatient department of our unit from January to June 2015, conforming to the study criteria, were enrolled in. For the first 12 patients, one wound on the limbs or torso was selected from each patient. The stability of the system was tested by 3 attending physicians using three dimensional human body scanning system BurnCalc to measure the area of wounds individually. For the following 36 patients, one wound was selected from each patient, including 12 wounds on limbs, front torso, and side torso, respectively. The area of wounds was measured by the same attending physician using transparency tracing method, National Institutes of Health (NIH) Image J method, and three dimensional human body scanning system BurnCalc, respectively. The time for getting information of 36 wounds by three methods was recorded by stopwatch. The stability among the testers was evaluated by the intra-class correlation coefficient (ICC). Data were processed with randomized blocks analysis of variance and Bonferroni test. Results: (1) Wound area of patients measured by three physicians using three dimensional human body scanning system BurnCalc was (122±95), (121±95), and (123±96) cm(2,) respectively, and there was no statistically significant difference among them ( F =1.55, P >0.05). The ICC among 3 physicians was 0.999. (2) The wound area of limbs of patients measured by transparency tracing method, NIH Image J method, and three dimensional human body scanning system BurnCalc was (84±50), (76±46), and (84±49) cm(2,) respectively. There was no statistically significant difference in the wound area of limbs of patients measured by transparency tracing method and three dimensional human body scanning system BurnCalc ( P >0.05). The wound area of limbs of patients

Highly ordered three-dimensional macroporous carbon spheres for determination of heavy metal ions

International Nuclear Information System (INIS)

Zhang, Yuxiao; Zhang, Jianming; Liu, Yang; Huang, Hui; Kang, Zhenhui

2012-01-01

Highlights: ► Highly ordered three dimensional macroporous carbon spheres (MPCSs) were prepared. ► MPCS was covalently modified by cysteine (MPCS–CO–Cys). ► MPCS–CO–Cys was first time used in electrochemical detection of heavy metal ions. ► Heavy metal ions such as Pb 2+ and Cd 2+ can be simultaneously determined. -- Abstract: An effective voltammetric method for detection of trace heavy metal ions using chemically modified highly ordered three dimensional macroporous carbon spheres electrode surfaces is described. The highly ordered three dimensional macroporous carbon spheres were prepared by carbonization of glucose in silica crystal bead template, followed by removal of the template. The highly ordered three dimensional macroporous carbon spheres were covalently modified by cysteine, an amino acid with high affinities towards some heavy metals. The materials were characterized by physical adsorption of nitrogen, scanning electron microscopy, and transmission electron microscopy techniques. While the Fourier-transform infrared spectroscopy was used to characterize the functional groups on the surface of carbon spheres. High sensitivity was exhibited when this material was used in electrochemical detection (square wave anodic stripping voltammetry) of heavy metal ions due to the porous structure. And the potential application for simultaneous detection of heavy metal ions was also investigated.

Assessment of Mitral Valve Stenosis by Simplifying Proximal Isovelocity Surface Area in Iraqi Patients by Transthoracic Echocardiography

Directory of Open Access Journals (Sweden)

Ghazi F. Haji

2018-02-01

Full Text Available Background: Mitral Stenosis refers to narrowing of the mitral valve orifice, resulting in impairment of filling of the left ventricle in diastole. Proximal isovelocity surface area measurement, also known as the flow convergence method, can be used in transthoracic echocardiography to estimate the area of an orifice through which blood flows. Objectives: To compare simple PISA equation, created by combined fixing the angle to 1000 and the Val to 33 cm/s, with mitral valve area measured by pressure half time and planimetry which was taken as reference method. Patients and Methods: A cross sectional prospective study was conducted in multi teaching centers. Total 104 patients were enrolled in this study from which 41 were excluded from the study. Transthoracic echocardiographic examination was used to analyze parameters selected by M-mode, 2D, and pulse doppler. Results: The patients enrolled in this study were with a mean age of 45.4 ± 7.1 years and 23.8% of them within the age group 30-39 years and the remaining 76.2% were >40 years. Female patients were the dominant represented 73.0% while males were 7.0% of the studied group (female: male ratio was 3:1; 61.9% were in sinus rhythm and 38.1% in atrial fibrillation. About 58.7% of the patients had Wilkin’s score less than 8, the mean mitral valve area according to planimetry method was 1.14 ± 0.32 cm2 and it was 1.12 ± 0.28 cm2 by PISA while the mean mitral valve area by pressure half time method was 1.19 ± 0.30 cm2 . The agreement between PISA and planimetry revealed that PISA had good agreement with planimetry in diagnosis of mitral stenosis, (kappa=0.835, P<0.001. On the other hand, there was a fair significant agreement between pressure half time and planimetry. Conclusion: PISA method can effectively predict mitral valve area and severity of mitral stenosis by the equation: mitral valve area = 115 × r2 /Vmax, provided that aliasing velocity is fixed at 33 cm/s, with the advantage of

Three-dimensional hologram display system

Science.gov (United States)

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.

Three-dimensional supersonic vortex breakdown

Science.gov (United States)

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

1993-01-01

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

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.

Evaluation of changes in left ventricular structure and function in hypertensive patients with coronary artery disease after PCI using real-time three-dimensional echocardiography.

Science.gov (United States)

Meng, Yanhong; Zong, Ling; Zhang, Ziteng; Han, Youdong; Wang, Yanhui

2018-02-01

We aimed to evaluate the changes in left ventricular structure and function in hypertensive patients with coronary artery disease before and after percutaneous coronary intervention (PCI) using real-time three-dimensional echocardiography. Two hundred and eighty hypertensive patients with coronary artery disease undergoing PCI and 120 cases who did not receive PCI in our hospital were selected as the subjects of our study. All patients were administered with routine antiplatelet, anticoagulant, lipid-lowering, antihypertensive, dilating coronary artery and other medications. The left ventricular systolic function and systolic synchrony index changes before and after subjects were treated by PCI were analyzed using three-dimensional echocardiography. At 2 days before surgery, there were no significant differences in the left ventricular end-diastolic volume, left ventricular end-systolic volume (LVESV) and ejection fraction (EF) between the two patient groups (P>0.05). At 3 months and 9 months, the two key time points after PCI, the LVESV level in the PCI group was distinctly decreased, while EF was significantly increased (P0.05); however, the parameters of time from the corresponding segment of the myocardium to the minimal systolic volume in patients in the PCI group were significantly reduced at 3 and 9 months after surgery (PPCI accurately and in real-time, which may play a significant role.

Three-dimensional reacting shock–bubble interaction

NARCIS (Netherlands)

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

Three-dimensional organization of the human interphase nucleus: Experiments compared to simulations.

NARCIS (Netherlands)

T.A. Knoch (Tobias); C. Münkel (Christian); W. Waldeck (Waldemar); J. Langowski (Jörg)

2000-01-01

markdownabstractDespite the successful linear sequencing of the human genome its three-dimensional structure is widely unknown, although it is important for gene regulation and replication. For a long time the interphase nucleus has been viewed as a 'spaghetti soup' of DNA without much internal

Three-dimensional vortex analysis and aeroacoustic source characterization of jet core breakdown

NARCIS (Netherlands)

Violato, D.; Scarano, F.

2013-01-01

The three-dimensional behavior of jet core breakdown is investigated with experiments conducted on a free water jet at Re = 5000 by time-resolved tomographic particle image velocimetry (TR-TOMO PIV). The investigated domain encompasses the range between 0 and 10 jet diameters. The characteristic

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....

Eustachian tube three-dimensional reconstruction of secretory otitis media

International Nuclear Information System (INIS)

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

2006-01-01

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

Computerized three-dimensional normal atlas

International Nuclear Information System (INIS)

Mano, Isamu; Suto, Yasuzo; Suzuki, Masataka; Iio, Masahiro.

1990-01-01

This paper presents our ongoing project in which normal human anatomy and its quantitative data are systematically arranged in a computer. The final product, the Computerized Three-Dimensional Normal Atlas, will be able to supply tomographic images in any direction, 3-D images, and coded information on organs, e.g., anatomical names, CT numbers, and T 1 and T 2 values. (author)

Three-Dimensional Shallow Water Acoustics

Science.gov (United States)

2016-03-30

medium properties, so horizontal refraction and reflection of sound can occur and produce significant three-dimensional (3-D) sound propagation ...by the environmental factors existing commonly in the continental shelf and shelfbreak areas, such as slopes, submarine canyons, sub-bottom layers ...surface waves, internal waves and shelfbreak fronts. 15. SUBJECT TERMS Continental Shelf; 3-D Acoustics , Surface Waves, Sound Propagation 16

Development of 2-D/1-D fusion method for three-dimensional whole-core heterogeneous neutron transport calculations

International Nuclear Information System (INIS)

Lee, Gil Soo

2006-02-01

To describe power distribution and multiplication factor of a reactor core accurately, it is necessary to perform calculations based on neutron transport equation considering heterogeneous geometry and scattering angles. These calculations require very heavy calculations and were nearly impossible with computers of old days. From the limitation of computing power, traditional approach of reactor core design consists of heterogeneous transport calculation in fuel assembly level and whole core diffusion nodal calculation with assembly homogenized properties, resulting from fuel assembly transport calculation. This approach may be effective in computation time, but it gives less accurate results for highly heterogeneous problems. As potential for whole core heterogeneous transport calculation became more feasible owing to rapid development of computing power during last several years, the interests in two and three dimensional whole core heterogeneous transport calculations by deterministic method are increased. For two dimensional calculation, there were several successful approaches using even parity transport equation with triangular meshes, S N method with refined rectangular meshes, the method of characteristics (MOC) with unstructured meshes, and so on. The work in this thesis originally started from the two dimensional whole core heterogeneous transport calculation by using MOC. After successful achievement in two dimensional calculation, there were efforts in three-dimensional whole-core heterogeneous transport calculation using MOC. Since direct extension to three dimensional calculation of MOC requires too much computing power, indirect approach to three dimensional calculation was considered.Thus, 2D/1D fusion method for three dimensional heterogeneous transport calculation was developed and successfully implemented in a computer code. The 2D/1D fusion method is synergistic combination of the MOC for radial 2-D calculation and S N -like methods for axial 1

Neuronavigation for arteriovenous malformation surgery by intraoperative three-dimensional ultrasound angiography.

Science.gov (United States)

Mathiesen, Tiit; Peredo, Inti; Edner, Göran; Kihlström, Lars; Svensson, Mikael; Ulfarsson, Elfar; Andersson, Tommy

2007-04-01

Neuronavigational devices have traditionally used preoperative imaging with limited possibilities for adjustment to brain shift and intraoperative manipulation of the surgical lesions. We have used an intraoperative imaging and navigation system that uses navigation on intraoperatively acquired three-dimensional ultrasound data, as well as preoperatively acquired magnetic resonance imaging scans and magnetic resonance angiograms. The usefulness of this system for arteriovenous malformation (AVM) surgery was evaluated prospectively. Nine consecutive patients with Spetzler Grade 1 (n = 3), 2 (n = 3), 3(n = 2) or 4 (n = 1) AVMs underwent operation using this intraoperative imaging and navigation system. The system provides real-time rendering of three-dimensional angiographic data and can visualize such projections in a stereoscopic (virtual reality) manner using special glasses. The experiences with this technology were analyzed and the outcomes assessed. Angiographic reconstructions of three-dimensional images were obtained before and after resection. Conventional navigation on the basis of preoperative magnetic resonance angiography was helpful to secure positioning of the bone flap; stereoscopic visualization of the same data represented a powerful means to construct a mental three-dimensional picture of the extent of the AVM and the feeder anatomy even before skin incision. Intraoperative ultrasound corresponded well to the intraoperative findings and allowed confirmation of feeding vessels in surrounding gyri and rapid identification of the perinidal dissection planes, regardless of brain shift. The latter feature was particularly helpful because the intraoperative navigational identification of surgical planes leads to minimal exploration into the nidus or dissection at a greater distance from the malformation. Application of the system was thought to increase surgical confidence. In two patients, postresection ultrasound prompted additional nidus removal

Three-dimensional helical (spiral) CT angiography. Visualization of vessels in the maxillofacial regions

International Nuclear Information System (INIS)

Hanawa, Shigeo; Sakamoto, Hidetomo; Mori, Shin-ichiro; Kagawa, Toyohiro; Seze, Ryosuke; Ishioka, Hisakazu; Tashiro, Himiko; Ogawa, Kazuhisa; Wada, Tadako

1998-01-01

Authors performed the contrast helical CT for tumors on the maxillofacial regions, and reconstituted these data into the three-dimensional helical (spiral) CT angiography (CTA). Furthermore the conditions of photographing and the clinical significance of CTA were discussed. The subjects were 24 cases (including 13 of malignant tumors, 4 of benign tumors, 4 of inflammation and 3 of malformations), to which the contrast helical CT was performed transvenously. The photographing condition was set in principal to 140 kV of the tube voltage, 160 (200) mA of the tube current, 3 mm of the X-ray beam width, 3 mm/sec (pitch=1) of the turn-table moving speed. The relationship between the beam width and the pitch was determined by the phantom experiments. The scanning was carried out maximally for continuous 60 sec as the scanning time of a turn/sec. Of all cases, CTA visualized three-dimensionally vessels, but it was hard in the total carotid arteries and the internal-external carotid arteries. Authors analyzed the axial and the multiplanar reconstitution (MPR) images as the two-dimensional display, and the surface rendering (SR), the volume rendering and the maximum intensity projections (MIP) as the three-dimensional display. The axial and MPR image of the facial arteries and the lingual arteries as the branched vessels from the external carotid arteries were recognized easily. By SR, it was easily to understand the anatomical relationship among vessels, gnathic bone and cervical vertebrae, and by MIP sufficiently observe the concentration dependent calcification of the vessel walls. Three-dimensional CTA is very useful to get the three-dimensional visual information about the anatomical structures of the maxillofacial regions which is necessary for oral surgeons to plan the pre-operational strategies. (K.H.)

Three dimensional CT imaging of ossicular chain: a preliminary study

International Nuclear Information System (INIS)

Hu Chunhong; Zhong Shenbin; Fu Yindi; Zhu Wei; Wang Xueyuan; Chen Jianhua; Ding Yi

2001-01-01

Objective: To analysis the features of normal and abnormal ossicular chain in three dimensional images and asses the best parameters and its usefulness in diagnosis and treatment of chronic otitis media (COM). Methods: All patients, including 43 patients with normal ears and 24 ears with COM, were examined using spiral CT with inner ear software, 1-mm slice width and 1 pitch. SSD method was used in three dimensional reconstruction and the threshold was 100-300 Hu. Results: In normal cases, Malleus, incus, stapes crura, incudomalleal joints and incudostapedial joints were displayed well, but stapes footplate unsatisfactorily. The disruption of the ossicular chain showed in three-dimensional images in cases of chronic otitis media was in accord with that seen in the operation. Conclusion: It is very important for imaging with high quality through selecting proper parameters, and three-dimensional image can provide valuable information for surgery

Three dimensional digital imaging of environmental data

International Nuclear Information System (INIS)

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

1991-01-01

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

Three-dimensional detonation cellular structures in rectangular ducts using an improved CESE scheme

International Nuclear Information System (INIS)

Shen Yang; Liu Kai-Xin; Chen Pu; Shen Hua; Zhang De-Liang

2016-01-01

The three-dimensional premixed H 2 -O 2 detonation propagation in rectangular ducts is simulated using an in-house parallel detonation code based on the second-order space–time conservation element and solution element (CE/SE) scheme. The simulation reproduces three typical cellular structures by setting appropriate cross-sectional size and initial perturbation in square tubes. As the cross-sectional size decreases, critical cellular structures transforming the rectangular or diagonal mode into the spinning mode are obtained and discussed in the perspective of phase variation as well as decreasing of triple point lines. Furthermore, multiple cellular structures are observed through examples with typical aspect ratios. Utilizing the visualization of detailed three-dimensional structures, their formation mechanism is further analyzed. (paper)

Three-dimensional Imaging, Visualization, and Display

CERN Document Server

Javidi, Bahram; Son, Jung-Young

2009-01-01

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

Quantification of three-dimensional cell-mediated collagen remodeling using graph theory.

Science.gov (United States)

Bilgin, Cemal Cagatay; Lund, Amanda W; Can, Ali; Plopper, George E; Yener, Bülent

2010-09-30

Cell cooperation is a critical event during tissue development. We present the first precise metrics to quantify the interaction between mesenchymal stem cells (MSCs) and extra cellular matrix (ECM). In particular, we describe cooperative collagen alignment process with respect to the spatio-temporal organization and function of mesenchymal stem cells in three dimensions. We defined two precise metrics: Collagen Alignment Index and Cell Dissatisfaction Level, for quantitatively tracking type I collagen and fibrillogenesis remodeling by mesenchymal stem cells over time. Computation of these metrics was based on graph theory and vector calculus. The cells and their three dimensional type I collagen microenvironment were modeled by three dimensional cell-graphs and collagen fiber organization was calculated from gradient vectors. With the enhancement of mesenchymal stem cell differentiation, acceleration through different phases was quantitatively demonstrated. The phases were clustered in a statistically significant manner based on collagen organization, with late phases of remodeling by untreated cells clustering strongly with early phases of remodeling by differentiating cells. The experiments were repeated three times to conclude that the metrics could successfully identify critical phases of collagen remodeling that were dependent upon cooperativity within the cell population. Definition of early metrics that are able to predict long-term functionality by linking engineered tissue structure to function is an important step toward optimizing biomaterials for the purposes of regenerative medicine.

Quantification of three-dimensional cell-mediated collagen remodeling using graph theory.

Directory of Open Access Journals (Sweden)

Cemal Cagatay Bilgin

2010-09-01

Full Text Available Cell cooperation is a critical event during tissue development. We present the first precise metrics to quantify the interaction between mesenchymal stem cells (MSCs and extra cellular matrix (ECM. In particular, we describe cooperative collagen alignment process with respect to the spatio-temporal organization and function of mesenchymal stem cells in three dimensions.We defined two precise metrics: Collagen Alignment Index and Cell Dissatisfaction Level, for quantitatively tracking type I collagen and fibrillogenesis remodeling by mesenchymal stem cells over time. Computation of these metrics was based on graph theory and vector calculus. The cells and their three dimensional type I collagen microenvironment were modeled by three dimensional cell-graphs and collagen fiber organization was calculated from gradient vectors. With the enhancement of mesenchymal stem cell differentiation, acceleration through different phases was quantitatively demonstrated. The phases were clustered in a statistically significant manner based on collagen organization, with late phases of remodeling by untreated cells clustering strongly with early phases of remodeling by differentiating cells. The experiments were repeated three times to conclude that the metrics could successfully identify critical phases of collagen remodeling that were dependent upon cooperativity within the cell population.Definition of early metrics that are able to predict long-term functionality by linking engineered tissue structure to function is an important step toward optimizing biomaterials for the purposes of regenerative medicine.

Tracker: A three-dimensional raytracing program for ionospheric radio propagation

Energy Technology Data Exchange (ETDEWEB)

Argo, P.E.; DeLapp, D.; Sutherland, C.D.; Farrer, R.G.

1994-12-01

TRACKER is an extension of a three-dimensional Hamiltonian raytrace code developed some thirty years ago by R. Michael Jones. Subsequent modifications to this code, which is commonly called the {open_quotes}Jones Code,{close_quotes} were documented by Jones and Stephensen (1975). TRACKER incorporates an interactive user`s interface, modern differential equation integrators, graphical outputs, homing algorithms, and the Ionospheric Conductivity and Electron Density (ICED) ionosphere. TRACKER predicts the three-dimensional paths of radio waves through model ionospheres by numerically integrating Hamilton`s equations, which are a differential expression of Fermat`s principle of least time. By using continuous models, the Hamiltonian method avoids false caustics and discontinuous raypath properties often encountered in other raytracing methods. In addition to computing the raypath, TRACKER also calculates the group path (or pulse travel time), the phase path, the geometrical (or {open_quotes}real{close_quotes}) pathlength, and the Doppler shift (if the time variation of the ionosphere is explicitly included). Computational speed can be traded for accuracy by specifying the maximum allowable integration error per step in the integration. Only geometrical optics are included in the main raytrace code; no partial reflections or diffraction effects are taken into account. In addition, TRACKER does not lend itself to statistical descriptions of propagation -- it requires a deterministic model of the ionosphere.

Three-dimensional radiation treatment planning

International Nuclear Information System (INIS)

Mohan, R.

1989-01-01

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

Three-dimensional cooling of muons

CERN Document Server

Vsevolozhskaya, T A

2000-01-01

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

Vibrational spectra and thermal rectification in three-dimensional anharmonic lattices

International Nuclear Information System (INIS)

Lan Jinghua; Li Baowen

2007-01-01

We study thermal rectification in a three-dimensional model consisting of two segments of anharmonic lattices. One segment consists of layers of harmonic oscillator arrays coupled to a substrate potential, which is a three-dimensional Frenkel-Kontorova model, and the other segment is a three-dimensional Fermi-Pasta-Ulam model. We study the vibrational bands of the two lattices analytically and numerically, and find that, by choosing the system parameters properly, the rectification can be as high as a few thousands, which is high enough to be observed in experiment. Possible experiments in nanostructures are discussed

Characterizing College Science Assessments: The Three-Dimensional Learning Assessment Protocol

Science.gov (United States)

Underwood, Sonia M.; 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, similar changes are underway in 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, chemistry, and physics that align with transformation efforts. We describe the development process used by our interdisciplinary team, discuss the validity and reliability of the protocol, and provide evidence that the protocol can distinguish between assessments that have the potential to elicit evidence of three-dimensional learning and those that do not. PMID:27606671

Characterizing College Science Assessments: The Three-Dimensional Learning Assessment Protocol.

Science.gov (United States)

Laverty, James T; Underwood, Sonia M; 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, similar changes are underway in 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, chemistry, and physics that align with transformation efforts. We describe the development process used by our interdisciplinary team, discuss the validity and reliability of the protocol, and provide evidence that the protocol can distinguish between assessments that have the potential to elicit evidence of three-dimensional learning and those that do not.

Mass effects in three-point chronological current correlators in n-dimensional multifermion models

International Nuclear Information System (INIS)

Kucheryavyj, V.I.

1991-01-01

Three-types of quantities associated with three-point chronological fermion-current correlators having arbitrary Lorentz and internal structure are calculated in the n-dimensional multifermion models with different masses. The analysis of vector and axial-vector Ward identities for regular (finite) and dimensionally regularized values of these quantities is carried out. Quantum corrections to the canonical Ward identities are obtained. These corrections are generally homogenious functions of zeroth order in masses and under some definite conditions they are reduced to known axial-vector anomalies. The structure and properties of quantum corrections to AVV and AAA correlators in the four-dimension space-time are investigated in detail

Evaluating the effect of three-dimensional visualization on force application and performance time during robotics-assisted mitral valve repair.

Science.gov (United States)

Currie, Maria E; Trejos, Ana Luisa; Rayman, Reiza; Chu, Michael W A; Patel, Rajni; Peters, Terry; Kiaii, Bob B

2013-01-01

The purpose of this study was to determine the effect of three-dimensional (3D) binocular, stereoscopic, and two-dimensional (2D) monocular visualization on robotics-assisted mitral valve annuloplasty versus conventional techniques in an ex vivo animal model. In addition, we sought to determine whether these effects were consistent between novices and experts in robotics-assisted cardiac surgery. A cardiac surgery test-bed was constructed to measure forces applied during mitral valve annuloplasty. Sutures were passed through the porcine mitral valve annulus by the participants with different levels of experience in robotics-assisted surgery and tied in place using both robotics-assisted and conventional surgery techniques. The mean time for both the experts and the novices using 3D visualization was significantly less than that required using 2D vision (P robotic system with either 2D or 3D vision (P robotics-assisted mitral valve annuloplasty than during conventional open mitral valve annuloplasty. This finding suggests that 3D visualization does not fully compensate for the absence of haptic feedback in robotics-assisted cardiac surgery.

Three dimensional imaging technique for laser-plasma diagnostics

International Nuclear Information System (INIS)

Jiang Shaoen; Zheng Zhijian; Liu Zhongli

2001-01-01

A CT technique for laser-plasma diagnostic and a three-dimensional (3D) image reconstruction program (CT3D) have been developed. The 3D images of the laser-plasma are reconstructed by using a multiplication algebraic reconstruction technique (MART) from five pinhole camera images obtained along different sight directions. The technique has been used to measure the three-dimensional distribution of X-ray of laser-plasma experiments in Xingguang II device, and the good results are obtained. This shows that a CT technique can be applied to ICF experiments

Three dimensional imaging technique for laser-plasma diagnostics

Energy Technology Data Exchange (ETDEWEB)

Shaoen, Jiang; Zhijian, Zheng; Zhongli, Liu [China Academy of Engineering Physics, Chengdu (China)

2001-04-01

A CT technique for laser-plasma diagnostic and a three-dimensional (3D) image reconstruction program (CT3D) have been developed. The 3D images of the laser-plasma are reconstructed by using a multiplication algebraic reconstruction technique (MART) from five pinhole camera images obtained along different sight directions. The technique has been used to measure the three-dimensional distribution of X-ray of laser-plasma experiments in Xingguang II device, and the good results are obtained. This shows that a CT technique can be applied to ICF experiments.

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

DEFF Research Database (Denmark)

Parigi, Dario; Pugnale, Alberto

2012-01-01

, causing every configuration to develop naturally out-of the plane. The structures presented here were developed and built by the students of the Master of Science in “Architectural Design” during a two week long workshop organized at Aalborg University in the fall semester 2011.......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 other...

Tensor of effective susceptibility in random magnetic composites: Application to two-dimensional and three-dimensional cases

Science.gov (United States)

Posnansky, Oleg P.

2018-05-01

The measuring of dynamic magnetic susceptibility by nuclear magnetic resonance is used for revealing information about the internal structure of various magnetoactive composites. The response of such material on the applied external static and time-varying magnetic fields encodes intrinsic dynamic correlations and depends on links between macroscopic effective susceptibility and structure on the microscopic scale. In the current work we carried out computational analysis of the frequency dependent dynamic magnetic susceptibility and demonstrated its dependence on the microscopic architectural elements while also considering Euclidean dimensionality. The proposed numerical method is efficient in the simulation of nuclear magnetic resonance experiments in two- and three-dimensional random magnetic media by choosing and modeling the influence of the concentration of components and internal hierarchical characteristics of physical parameters.

Development of three-dimensional individual bubble-velocity measurement method by bubble tracking

International Nuclear Information System (INIS)

Kanai, Taizo; Furuya, Masahiro; Arai, Takahiro; Shirakawa, Kenetsu; Nishi, Yoshihisa

2012-01-01

A gas-liquid two-phase flow in a large diameter pipe exhibits a three-dimensional flow structure. Wire-Mesh Sensor (WMS) consists of a pair of parallel wire layers located at the cross section of a pipe. Both the parallel wires cross at 90o with a small gap and each intersection acts as an electrode. The WMS allows the measurement of the instantaneous two-dimensional void-fraction distribution over the cross-section of a pipe, based on the difference between the local instantaneous conductivity of the two-phase flow. Furthermore, the WMS can acquire a phasic-velocity on the basis of the time lag of void signals between two sets of WMS. Previously, the acquired phasic velocity was one-dimensional with time-averaged distributions. The authors propose a method to estimate the three-dimensional bubble-velocity individually WMS data. The bubble velocity is determined by the tracing method. In this tracing method, each bubble is separated from WMS signal, volume and center coordinates of the bubble is acquired. Two bubbles with near volume at two WMS are considered as the same bubble and bubble velocity is estimated from the displacement of the center coordinates of the two bubbles. The validity of this method is verified by a swirl flow. The proposed method can successfully visualize a swirl flow structure and the results of this method agree with the results of cross-correlation analysis. (author)

On a model of three-dimensional bursting and its parallel implementation

Science.gov (United States)

Tabik, S.; Romero, L. F.; Garzón, E. M.; Ramos, J. I.

2008-04-01

A mathematical model for the simulation of three-dimensional bursting phenomena and its parallel implementation are presented. The model consists of four nonlinearly coupled partial differential equations that include fast and slow variables, and exhibits bursting in the absence of diffusion. The differential equations have been discretized by means of a second-order accurate in both space and time, linearly-implicit finite difference method in equally-spaced grids. The resulting system of linear algebraic equations at each time level has been solved by means of the Preconditioned Conjugate Gradient (PCG) method. Three different parallel implementations of the proposed mathematical model have been developed; two of these implementations, i.e., the MPI and the PETSc codes, are based on a message passing paradigm, while the third one, i.e., the OpenMP code, is based on a shared space address paradigm. These three implementations are evaluated on two current high performance parallel architectures, i.e., a dual-processor cluster and a Shared Distributed Memory (SDM) system. A novel representation of the results that emphasizes the most relevant factors that affect the performance of the paralled implementations, is proposed. The comparative analysis of the computational results shows that the MPI and the OpenMP implementations are about twice more efficient than the PETSc code on the SDM system. It is also shown that, for the conditions reported here, the nonlinear dynamics of the three-dimensional bursting phenomena exhibits three stages characterized by asynchronous, synchronous and then asynchronous oscillations, before a quiescent state is reached. It is also shown that the fast system reaches steady state in much less time than the slow variables.

Three dimensional analysis of cosmic ray intensity variation

International Nuclear Information System (INIS)

Yasue, Shin-ichi; Mori, Satoru; Nagashima, Kazuo.

1974-01-01

Three dimensional analysis of cosmic ray anisotropy and its time variation was performed. This paper describes the analysis of the Forbush decrease in Jan. 1968 to investigate by comparing the direction of the magnetic field in interplanetary space and the direction of the reference axis for cosmic ray anisotropy. New anisotropy becomes dominant at the time of Forbush decrease because the anisotropy of cosmic ray in calm state is wiped out. Such anisotropy produces intensity variation in neutron monitors on the ground. The characteristic parameters of three dimensional anisotropy can be determined from theoretical value and observed intensity. Analyzed data were taken for 6 days from Jan. 25 to Jan. 30, 1968, at Deep River. The decrease of intensity at Deep River was seen for several hours from 11 o'clock (UT), Jan. 26, just before The Forbush decrease. This may be due to the loss cone. The Forbush decrease began at 19 o'clock, Jan. 26, and the main phase continued to 5 o'clock in the next morning. The spectrum of variation was Psup(-0.5). The time variations of the magnetic field in interplanetary space and the reference axis of cosmic ray anisotropy are shown for 15 hours. The average directions of both are almost in coincidence. The spatial distribution of cosmic ray near the earth may be expressed by the superposition of axial symmetrical distribution along a reference axis and its push-out to the direction of 12 o'clock. It is considered that the direction of magnetic force line and the velocity of solar wind correspond to the direction of the reference axis and the magnitude of anisotropy in the direction of 12 o'clock, respectively. (Kato, T.)

Flukacad/Pipsicad: three-dimensional interfaces between Fluka and Autocad

International Nuclear Information System (INIS)

Helmut Vincke

2001-01-01

FLUKA is a widely used 3-D particle transport program. Up to now there was no possibility to display the simulation geometry or the calculated tracks in three dimensions. Even with FLUKA there exists only an option to picture two-dimensional views through the geometry used. This paper covers the description of two interface programs between the particle transport code FLUKA and the CAD program AutoCAD. These programs provide a three-dimensional facility not only for illustrating the simulated FLUKA geometry (FLUKACAD), but also for picturing simulated particle tracks (PIPSICAD) in a three-dimensional set-up. Additionally, the programming strategy for connecting FLUKA with AutoCAD is shown. A number of useful features of the programs themselves, but also of AutoCAD in the context of FLUKACAD and PIPSICAD, are explained. (authors)

The three-dimensional distribution of atmospheric heating during the GWE

OpenAIRE

SCHAACK, TODD K.; JOHNSON, DONALD R.; WEI, MING-YING

2011-01-01

The three-dimensional global distributions of time-averaged atmospheric heating for January, April, July and October 1979 are estimated from the ECMWF GWE Level IIIb data set. Heating rates are calculated through a vertical integration of the isentropic equation of mass continuity. Estimates of the vertical variation of heating are presented in isobaric coordinates through interpolation of the vertical profiles of heating from isentropic to isobaric coordinates. The horizontal distributions o...

Usefulness of three dimensional reconstructive images for thoracic trauma induced fractures

Energy Technology Data Exchange (ETDEWEB)

Koh, Kyung Hun; Kim, Dong Hun; Kim, Young Sook; Byun, Joo Nam [Chosun University Hospital, Gwangju (Korea, Republic of)

2006-09-15

We wanted to evaluate the usefulness of three-dimensional reconstructive images using multidetector computed tomography (MDCT) for thoracic traumatic patients visiting emergency room. 76 patients with fractures of the 105 patients who visited our emergency room with complaints of thoracic trauma were analyzed retrospectively. All the patients had thoracic MDCT performed and the three-dimensional reconstructive images were taken. The fractures were confirmed by axial CT, the clinical information, whole body bone scanning and the multiplanar reformation images. Plain x-ray images were analyzed by the fractured sites in a blind comparison of two radiologists' readings, and then that finding was compared with the axial CT scans and the three-dimensional reconstructive images. The fracture sites were rib (n 68), sternum (n = 14), clavicle (n = 6), scapula (n = 3), spine (n = 5) and combined fractures (n = 14). Plain x-ray and axial CT scans had a correspondency of 0.555 for the rib fractures. Axial CT scans and the three-dimensional reconstructive images had a correspondency of .952. For sternal fractures, those values were 0.692 and 0.928, respectively. The axial CT scans and three-dimensional reconstructive images showed sensitivities of 94% and 91% for rib and other fractures, respectively, and 93% and 100% for sternal fracture, respectively. Three-dimensional reconstructive image had an especially high sensitivity for the diagnosis of sternal fracture. While evaluating thoracic trauma at the emergency room, the three-dimensional reconstructive image was useful to easily diagnose the extent of fracture and it was very sensitive for detecting sternal fracture.

Usefulness of three dimensional reconstructive images for thoracic trauma induced fractures

International Nuclear Information System (INIS)

Koh, Kyung Hun; Kim, Dong Hun; Kim, Young Sook; Byun, Joo Nam

2006-01-01

We wanted to evaluate the usefulness of three-dimensional reconstructive images using multidetector computed tomography (MDCT) for thoracic traumatic patients visiting emergency room. 76 patients with fractures of the 105 patients who visited our emergency room with complaints of thoracic trauma were analyzed retrospectively. All the patients had thoracic MDCT performed and the three-dimensional reconstructive images were taken. The fractures were confirmed by axial CT, the clinical information, whole body bone scanning and the multiplanar reformation images. Plain x-ray images were analyzed by the fractured sites in a blind comparison of two radiologists' readings, and then that finding was compared with the axial CT scans and the three-dimensional reconstructive images. The fracture sites were rib (n 68), sternum (n = 14), clavicle (n = 6), scapula (n = 3), spine (n = 5) and combined fractures (n = 14). Plain x-ray and axial CT scans had a correspondency of 0.555 for the rib fractures. Axial CT scans and the three-dimensional reconstructive images had a correspondency of .952. For sternal fractures, those values were 0.692 and 0.928, respectively. The axial CT scans and three-dimensional reconstructive images showed sensitivities of 94% and 91% for rib and other fractures, respectively, and 93% and 100% for sternal fracture, respectively. Three-dimensional reconstructive image had an especially high sensitivity for the diagnosis of sternal fracture. While evaluating thoracic trauma at the emergency room, the three-dimensional reconstructive image was useful to easily diagnose the extent of fracture and it was very sensitive for detecting sternal fracture

Scattering from a Buried Circular Cylinder Illuminated by a Three-Dimensional Source

DEFF Research Database (Denmark)

Hansen, T.B.; Meincke, Peter

2002-01-01

We employ plane and cylindrical wave expansions with the fast Fourier transform to solve scattering problems involving a circular cylinder buried in soil. The illumination is provided by a three-dimensional source located in air above ground. Plane wave expansions describe transmitted and reflect...... commonly used transmitter-receiver configuration for ground-penetrating radar (GPR). Numerical simulations involving time domain fields and fixed-offset configurations determine the radar responses of various types of pipes and conductive soils encountered in GPR.......We employ plane and cylindrical wave expansions with the fast Fourier transform to solve scattering problems involving a circular cylinder buried in soil. The illumination is provided by a three-dimensional source located in air above ground. Plane wave expansions describe transmitted and reflected...

Three-dimensional accuracy of plastic transfer impression copings for three implant systems.

Science.gov (United States)

Teo, Juin Wei; Tan, Keson B; Nicholls, Jack I; Wong, Keng Mun; Uy, Joanne

2014-01-01

The purpose of this study was to compare the three-dimensional accuracy of indirect plastic impression copings and direct implant-level impression copings from three implant systems (Nobel Biocare [NB], Biomet 3i [3i], and Straumann [STR]) at three interimplant buccolingual angulations (0, 8, and 15 degrees). Two-implant master models were used to simulate a three-unit implant fixed partial denture. Test models were made from Impregum impressions using direct implant-level impression copings (DR). Abutments were then connected to the master models for impressions using the plastic impression copings (INDR) at three different angulations for a total of 18 test groups (n = 5 in each group). A coordinate measuring machine was used to measure linear distortions, three-dimensional (3D) distortions, angular distortions, and absolute angular distortions between the master and test models. Three-way analysis of variance showed that the implant system had a significant effect on 3D distortions and absolute angular distortions in the x- and y-axes. Interimplant angulation had a significant effect on 3D distortions and absolute angular distortions in the y-axis. Impression technique had a significant effect on absolute angular distortions in the y-axis. With DR, the NB and 3i systems were not significantly different. With INDR, 3i appeared to have less distortion than the other systems. Interimplant angulations did not significantly affect the accuracy of NBDR, 3iINDR, and STRINDR. The accuracy of INDR and DR was comparable at all interimplant angulations for 3i and STR. For NB, INDR was comparable to DR at 0 and 8 degrees but was less accurate at 15 degrees. Three-dimensional accuracy of implant impressions varied with implant system, interimplant angulation, and impression technique.

Phase Diagrams of Three-Dimensional Anderson and Quantum Percolation Models Using Deep Three-Dimensional Convolutional Neural Network

Science.gov (United States)

Mano, Tomohiro; Ohtsuki, Tomi

2017-11-01

The three-dimensional Anderson model is a well-studied model of disordered electron systems that shows the delocalization-localization transition. As in our previous papers on two- and three-dimensional (2D, 3D) quantum phase transitions [J. Phys. Soc. Jpn. 85, 123706 (2016), 86, 044708 (2017)], we used an image recognition algorithm based on a multilayered convolutional neural network. However, in contrast to previous papers in which 2D image recognition was used, we applied 3D image recognition to analyze entire 3D wave functions. We show that a full phase diagram of the disorder-energy plane is obtained once the 3D convolutional neural network has been trained at the band center. We further demonstrate that the full phase diagram for 3D quantum bond and site percolations can be drawn by training the 3D Anderson model at the band center.

Kinematics of swimming of the manta ray: three-dimensional analysis of open-water maneuverability.

Science.gov (United States)

Fish, Frank E; Kolpas, Allison; Crossett, Andrew; Dudas, Michael A; Moored, Keith W; Bart-Smith, Hilary

2018-03-22

For aquatic animals, turning maneuvers represent a locomotor activity that may not be confined to a single coordinate plane, making analysis difficult, particularly in the field. To measure turning performance in a three-dimensional space for the manta ray ( Mobula birostris ), a large open-water swimmer, scaled stereo video recordings were collected. Movements of the cephalic lobes, eye and tail base were tracked to obtain three-dimensional coordinates. A mathematical analysis was performed on the coordinate data to calculate the turning rate and curvature (1/turning radius) as a function of time by numerically estimating the derivative of manta trajectories through three-dimensional space. Principal component analysis was used to project the three-dimensional trajectory onto the two-dimensional turn. Smoothing splines were applied to these turns. These are flexible models that minimize a cost function with a parameter controlling the balance between data fidelity and regularity of the derivative. Data for 30 sequences of rays performing slow, steady turns showed the highest 20% of values for the turning rate and smallest 20% of turn radii were 42.65±16.66 deg s -1 and 2.05±1.26 m, respectively. Such turning maneuvers fall within the range of performance exhibited by swimmers with rigid bodies. © 2018. Published by The Company of Biologists Ltd.

Plasma cloud expansion in the ionosphere: Three-dimensional simulation

International Nuclear Information System (INIS)

Ma, T.Z.; Schunk, R.W.

1991-01-01

A three-dimensional time-dependent model was developed to study the characteristics of a plasma cloud expansion in the ionosphere. The electrostatic potential is solved in three dimensions taking into account the large parallel-to-perpendicular conductivity ratio. Three sample simulations are presented: a plasma expansion of a nearly spherical 1 km Ba + cloud, both with and without a background neutral wind, and a long thin Ba + cloudlet. With or without the neutral wind the effective potential, which is different from the electrostatic potential if the electron temperature is included, is constant along the magnetic field for typical cloud sizes. The expanding plasma clouds become elongated in the magnetic field direction. The released Ba + ions push the background O + ions away along the magnetic field as they expand. Consequently, a hole develops in the background O + distribution at the cloud location and on the two sides of the cloud O + bumps form. The entire three-dimensional structure, composed of the plasma cloud and the background plasma embedded in the cloud, slowly rotates about the magnetic field, with the ions and electrons rotating in opposite directions. The cloud configuration takes the shape of a rotating ellipsoid with a major axis that expands with time. Perpendicular to the magnetic field, in the absence of the neutral wind the motion is insignificant compared to the parallel motion. With a neutral wind the motion along the magnetic field and the rotational motion are qualitatively unchanged, but the cloud and the perturbed background structure move in the direction of the wind, with a speed less than the wind speed. Perpendicular to the magnetic field the deformation of the cloud indiced by the wind is characterized by steepening of the backside

Effect of local automatic control rods on three-dimensional calculations of the power distribution in an RBMK

International Nuclear Information System (INIS)

Pogosbekyan, L.R.; Lysov, D.A.; Bronitskii, L.L.

1993-01-01

Numerical simulators and information systems that support nuclear reactor operators must have fast models to estimate how fuel reloads and control rod displacement affect neutron and power distributions in the core. The consequences of reloads and control rod displacement cannot be evaluated correctly without considering local automatic control-rod operations in maintaining the radial power distribution. Fast three-dimensional models to estimate the effects of reloads and displacement of the control and safety rods have already been examined. I.V. Zonov et al. used the following assumptions in their calculational model: (1) the full-scale problem could be reduced a three-dimensional fragment of a locally perturbed core, and (2) the boundary conditions of the fragment and its total power were constant. The last assumption considers approximately how local automatic control rods stabilize the radial power distribution, but three dimensional calculations with these rods are not considered. These assumptions were introduced to obtain high computational speed. I.L. Bronitskii et al. considered in more detail how moving the local automatic control rods affect the power dimensional in the three-dimensional fragment, because, with on-line monitoring of the reload process, information on control rod positions is periodically renewed, and the calculations are done in real time. This model to predict the three-dimensional power distribution to (1) do a preliminary reload analysis, and (2) prepare the core for reloading did not consider the effect of perturbations from the local automatic control rods. Here we examine a model of a stationary neutron distribution. On one hand it gives results in an acceptable computation time; on the other it is a full-scale three-dimensional model and considers how local automatic control rods affect both the radial and axial power distribution

Three dimensional force prediction in a model linear brushless dc motor

Energy Technology Data Exchange (ETDEWEB)

Moghani, J.S.; Eastham, J.F.; Akmese, R.; Hill-Cottingham, R.J. (Univ. of Bath (United Kingdom). School of Electronic and Electric Engineering)

1994-11-01

Practical results are presented for the three axes forces produced on the primary of a linear brushless dc machine which is supplied from a three-phase delta-modulated inverter. Conditions of both lateral alignment and lateral displacement are considered. Finite element analysis using both two and three dimensional modeling is compared with the practical results. It is shown that a modified two dimensional model is adequate, where it can be used, in the aligned position and that the full three dimensional method gives good results when the machine is axially misaligned.

Three-dimensional true FISP for high-resolution imaging of the whole brain

International Nuclear Information System (INIS)

Schmitz, B.; Hagen, T.; Reith, W.

2003-01-01

While high-resolution T1-weighted sequences, such as three-dimensional magnetization-prepared rapid gradient-echo imaging, are widely available, there is a lack of an equivalent fast high-resolution sequence providing T2 contrast. Using fast high-performance gradient systems we show the feasibility of three-dimensional true fast imaging with steady-state precession (FISP) to fill this gap. We applied a three-dimensional true-FISP protocol with voxel sizes down to 0.5 x 0.5 x 0.5 mm and acquisition times of approximately 8 min on a 1.5-T Sonata (Siemens, Erlangen, Germany) magnetic resonance scanner. The sequence was included into routine brain imaging protocols for patients with cerebrospinal-fluid-related intracranial pathology. Images from 20 patients and 20 healthy volunteers were evaluated by two neuroradiologists with respect to diagnostic image quality and artifacts. All true-FISP scans showed excellent imaging quality free of artifacts in patients and volunteers. They were valuable for the assessment of anatomical and pathologic aspects of the included patients. High-resolution true-FISP imaging is a valuable adjunct for the exploration and neuronavigation of intracranial pathologies especially if cerebrospinal fluid is involved. (orig.)

Visual Interpretation with Three-Dimensional Annotations (VITA): three-dimensional image interpretation tool for radiological reporting.

Science.gov (United States)

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

2014-02-01

This paper introduces a software framework called Visual Interpretation with Three-Dimensional Annotations (VITA) that is able to automatically generate three-dimensional (3D) visual summaries based on radiological annotations made during routine exam reporting. VITA summaries are in the form of rotating 3D volumes where radiological annotations are highlighted to place important clinical observations into a 3D context. The rendered volume is produced as a Digital Imaging and Communications in Medicine (DICOM) object and is automatically added to the study for archival in Picture Archiving and Communication System (PACS). In addition, a video summary (e.g., MPEG4) can be generated for sharing with patients and for situations where DICOM viewers are not readily available to referring physicians. The current version of VITA is compatible with ClearCanvas; however, VITA can work with any PACS workstation that has a structured annotation implementation (e.g., Extendible Markup Language, Health Level 7, Annotation and Image Markup) and is able to seamlessly integrate into the existing reporting workflow. In a survey with referring physicians, the vast majority strongly agreed that 3D visual summaries improve the communication of the radiologists' reports and aid communication with patients.

Flow predictions for MHD channels with an approximation for three-dimensional effects

International Nuclear Information System (INIS)

Blottner, F.G.

1978-01-01

A finite-difference procedure has been formulated for predicting the flow properties across channels. A quasi-two-dimensional approach has been developed which allows the three-dimensional channel effects to be taken into account. Comparison of the numerical solutions with experimental results show that this approach is a reasonable approximation for MHD flow conditions if there is not significant merging of the wall boundary layers. The resulting code provides a technique to obtain the flow details in the symmetry plane of the channel and requires only a small amount of computer time

Experimental characterization of an ultrafast Thomson scattering x-ray source with three-dimensional time and frequency-domain analysis

Directory of Open Access Journals (Sweden)

W. J. Brown

2004-06-01

Full Text Available We present a detailed comparison of the measured characteristics of Thomson backscattered x rays produced at the Picosecond Laser-Electron Interaction for the Dynamic Evaluation of Structures facility at Lawrence Livermore National Laboratory to predicted results from a newly developed, fully three-dimensional time and frequency-domain code. Based on the relativistic differential cross section, this code has the capability to calculate time and space dependent spectra of the x-ray photons produced from linear Thomson scattering for both bandwidth-limited and chirped incident laser pulses. Spectral broadening of the scattered x-ray pulse resulting from the incident laser bandwidth, perpendicular wave vector components in the laser focus, and the transverse and longitudinal phase spaces of the electron beam are included. Electron beam energy, energy spread, and transverse phase space measurements of the electron beam at the interaction point are presented, and the corresponding predicted x-ray characteristics are determined. In addition, time-integrated measurements of the x rays produced from the interaction are presented and shown to agree well with the simulations.

Highly ordered three-dimensional macroporous carbon spheres for determination of heavy metal ions

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yuxiao; Zhang, Jianming [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Liu, Yang, E-mail: yangl@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Huang, Hui [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Kang, Zhenhui, E-mail: zhkang@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China)

2012-04-15

Highlights: Black-Right-Pointing-Pointer Highly ordered three dimensional macroporous carbon spheres (MPCSs) were prepared. Black-Right-Pointing-Pointer MPCS was covalently modified by cysteine (MPCS-CO-Cys). Black-Right-Pointing-Pointer MPCS-CO-Cys was first time used in electrochemical detection of heavy metal ions. Black-Right-Pointing-Pointer Heavy metal ions such as Pb{sup 2+} and Cd{sup 2+} can be simultaneously determined. -- Abstract: An effective voltammetric method for detection of trace heavy metal ions using chemically modified highly ordered three dimensional macroporous carbon spheres electrode surfaces is described. The highly ordered three dimensional macroporous carbon spheres were prepared by carbonization of glucose in silica crystal bead template, followed by removal of the template. The highly ordered three dimensional macroporous carbon spheres were covalently modified by cysteine, an amino acid with high affinities towards some heavy metals. The materials were characterized by physical adsorption of nitrogen, scanning electron microscopy, and transmission electron microscopy techniques. While the Fourier-transform infrared spectroscopy was used to characterize the functional groups on the surface of carbon spheres. High sensitivity was exhibited when this material was used in electrochemical detection (square wave anodic stripping voltammetry) of heavy metal ions due to the porous structure. And the potential application for simultaneous detection of heavy metal ions was also investigated.

Three-dimensional simulation of flow, salinity, sediment, and radionuclide movements in the Hudson River estuary

International Nuclear Information System (INIS)

Onishi, Y.; Trent, D.S.

1985-04-01

The three-dimensional, finite difference model, FLESCOT simulates time-varying movements of flow, turbulent kinetic energy, salinity, water temperature, sediment, and contaminants in estuarine, coastal, and ocean waters. The model was applied to a 106-km (66-mi) reach of the Hudson River estuary in New York between Chelsea and the mouth of the river. It predicted the time-varying, three-dimensional distributions of tidal flow, salinity, three separate groups of sediments (i.e., sand, silt, and clay), and a radionuclide ( 137 Cs) in both dissolved and particulate (those sorbed by sediments) forms for over 40 days. The model also calculated riverbed elevation changes caused by sediment deposition and bed erosion, bed sediment size distribution and armoring, and distributions of the particulate 137 Cs sorbed by sand, silt, and clay in the bed

A seamless acquisition digital storage oscilloscope with three-dimensional waveform display

Energy Technology Data Exchange (ETDEWEB)

Yang, Kuojun, E-mail: kuojunyang@gmail.com; Guo, Lianping [School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu (China); School of Electrical and Electronic Engineering, Nanyang Technological University (Singapore); Tian, Shulin; Zeng, Hao [School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu (China); Qiu, Lei [School of Electrical and Electronic Engineering, Nanyang Technological University (Singapore)

2014-04-15

In traditional digital storage oscilloscope (DSO), sampled data need to be processed after each acquisition. During data processing, the acquisition is stopped and oscilloscope is blind to the input signal. Thus, this duration is called dead time. With the rapid development of modern electronic systems, the effect of infrequent events becomes significant. To capture these occasional events in shorter time, dead time in traditional DSO that causes the loss of measured signal needs to be reduced or even eliminated. In this paper, a seamless acquisition oscilloscope without dead time is proposed. In this oscilloscope, three-dimensional waveform mapping (TWM) technique, which converts sampled data to displayed waveform, is proposed. With this technique, not only the process speed is improved, but also the probability information of waveform is displayed with different brightness. Thus, a three-dimensional waveform is shown to the user. To reduce processing time further, parallel TWM which processes several sampled points simultaneously, and dual-port random access memory based pipelining technique which can process one sampling point in one clock period are proposed. Furthermore, two DDR3 (Double-Data-Rate Three Synchronous Dynamic Random Access Memory) are used for storing sampled data alternately, thus the acquisition can continue during data processing. Therefore, the dead time of DSO is eliminated. In addition, a double-pulse test method is adopted to test the waveform capturing rate (WCR) of the oscilloscope and a combined pulse test method is employed to evaluate the oscilloscope's capture ability comprehensively. The experiment results show that the WCR of the designed oscilloscope is 6 250 000 wfms/s (waveforms per second), the highest value in all existing oscilloscopes. The testing results also prove that there is no dead time in our oscilloscope, thus realizing the seamless acquisition.

A seamless acquisition digital storage oscilloscope with three-dimensional waveform display

Science.gov (United States)

Yang, Kuojun; Tian, Shulin; Zeng, Hao; Qiu, Lei; Guo, Lianping

2014-04-01

In traditional digital storage oscilloscope (DSO), sampled data need to be processed after each acquisition. During data processing, the acquisition is stopped and oscilloscope is blind to the input signal. Thus, this duration is called dead time. With the rapid development of modern electronic systems, the effect of infrequent events becomes significant. To capture these occasional events in shorter time, dead time in traditional DSO that causes the loss of measured signal needs to be reduced or even eliminated. In this paper, a seamless acquisition oscilloscope without dead time is proposed. In this oscilloscope, three-dimensional waveform mapping (TWM) technique, which converts sampled data to displayed waveform, is proposed. With this technique, not only the process speed is improved, but also the probability information of waveform is displayed with different brightness. Thus, a three-dimensional waveform is shown to the user. To reduce processing time further, parallel TWM which processes several sampled points simultaneously, and dual-port random access memory based pipelining technique which can process one sampling point in one clock period are proposed. Furthermore, two DDR3 (Double-Data-Rate Three Synchronous Dynamic Random Access Memory) are used for storing sampled data alternately, thus the acquisition can continue during data processing. Therefore, the dead time of DSO is eliminated. In addition, a double-pulse test method is adopted to test the waveform capturing rate (WCR) of the oscilloscope and a combined pulse test method is employed to evaluate the oscilloscope's capture ability comprehensively. The experiment results show that the WCR of the designed oscilloscope is 6 250 000 wfms/s (waveforms per second), the highest value in all existing oscilloscopes. The testing results also prove that there is no dead time in our oscilloscope, thus realizing the seamless acquisition.

A seamless acquisition digital storage oscilloscope with three-dimensional waveform display

International Nuclear Information System (INIS)

Yang, Kuojun; Guo, Lianping; Tian, Shulin; Zeng, Hao; Qiu, Lei

2014-01-01

In traditional digital storage oscilloscope (DSO), sampled data need to be processed after each acquisition. During data processing, the acquisition is stopped and oscilloscope is blind to the input signal. Thus, this duration is called dead time. With the rapid development of modern electronic systems, the effect of infrequent events becomes significant. To capture these occasional events in shorter time, dead time in traditional DSO that causes the loss of measured signal needs to be reduced or even eliminated. In this paper, a seamless acquisition oscilloscope without dead time is proposed. In this oscilloscope, three-dimensional waveform mapping (TWM) technique, which converts sampled data to displayed waveform, is proposed. With this technique, not only the process speed is improved, but also the probability information of waveform is displayed with different brightness. Thus, a three-dimensional waveform is shown to the user. To reduce processing time further, parallel TWM which processes several sampled points simultaneously, and dual-port random access memory based pipelining technique which can process one sampling point in one clock period are proposed. Furthermore, two DDR3 (Double-Data-Rate Three Synchronous Dynamic Random Access Memory) are used for storing sampled data alternately, thus the acquisition can continue during data processing. Therefore, the dead time of DSO is eliminated. In addition, a double-pulse test method is adopted to test the waveform capturing rate (WCR) of the oscilloscope and a combined pulse test method is employed to evaluate the oscilloscope's capture ability comprehensively. The experiment results show that the WCR of the designed oscilloscope is 6 250 000 wfms/s (waveforms per second), the highest value in all existing oscilloscopes. The testing results also prove that there is no dead time in our oscilloscope, thus realizing the seamless acquisition

Three-dimensional Simulation of Backward Raman Amplification

International Nuclear Information System (INIS)

Balakin, A.A.; Fraiman, G.M.; Fisch, N.J.

2005-01-01

Three-dimensional (3-D) simulations for the Backward Raman Amplification (BRA) are presented. The images illustrate the effects of pump depletion, pulse diffraction, non-homogeneous plasma density, and plasma ionization

Three-Dimensionally Printed Micro-electromechanical Switches.

Science.gov (United States)

Lee, Yongwoo; Han, Jungmin; Choi, Bongsik; Yoon, Jinsu; Park, Jinhee; Kim, Yeamin; Lee, Jieun; Kim, Dae Hwan; Kim, Dong Myong; Lim, Meehyun; Kang, Min-Ho; Kim, Sungho; Choi, Sung-Jin

2018-05-09

Three-dimensional (3D) printers have attracted considerable attention from both industry and academia and especially in recent years because of their ability to overcome the limitations of two-dimensional (2D) processes and to enable large-scale facile integration techniques. With 3D printing technologies, complex structures can be created using only a computer-aided design file as a reference; consequently, complex shapes can be manufactured in a single step with little dependence on manufacturer technologies. In this work, we provide a first demonstration of the facile and time-saving 3D printing of two-terminal micro-electromechanical (MEM) switches. Two widely used thermoplastic materials were used to form 3D-printed MEM switches; freely suspended and fixed electrodes were printed from conductive polylactic acid, and a water-soluble sacrificial layer for air-gap formation was printed from poly(vinyl alcohol). Our 3D-printed MEM switches exhibit excellent electromechanical properties, with abrupt switching characteristics and an excellent on/off current ratio value exceeding 10 6 . Therefore, we believe that our study makes an innovative contribution with implications for the development of a broader range of 3D printer applications (e.g., the manufacturing of various MEM devices and sensors), and the work highlights a uniquely attractive path toward the realization of 3D-printed electronics.

[Three-dimensional computer aided design for individualized post-and-core restoration].

Science.gov (United States)

Gu, Xiao-yu; Wang, Ya-ping; Wang, Yong; Lü, Pei-jun

2009-10-01

To develop a method of three-dimensional computer aided design (CAD) of post-and-core restoration. Two plaster casts with extracted natural teeth were used in this study. The extracted teeth were prepared and scanned using tomography method to obtain three-dimensional digitalized models. According to the basic rules of post-and-core design, posts, cores and cavity surfaces of the teeth were designed using the tools for processing point clouds, curves and surfaces on the forward engineering software of Tanglong prosthodontic system. Then three-dimensional figures of the final restorations were corrected according to the configurations of anterior teeth, premolars and molars respectively. Computer aided design of 14 post-and-core restorations were finished, and good fitness between the restoration and the three-dimensional digital models were obtained. Appropriate retention forms and enough spaces for the full crown restorations can be obtained through this method. The CAD of three-dimensional figures of the post-and-core restorations can fulfill clinical requirements. Therefore they can be used in computer-aided manufacture (CAM) of post-and-core restorations.

Analytical three-dimensional neutron transport benchmarks for verification of nuclear engineering codes. Final report

International Nuclear Information System (INIS)

Ganapol, B.D.; Kornreich, D.E.

1997-01-01

Because of the requirement of accountability and quality control in the scientific world, a demand for high-quality analytical benchmark calculations has arisen in the neutron transport community. The intent of these benchmarks is to provide a numerical standard to which production neutron transport codes may be compared in order to verify proper operation. The overall investigation as modified in the second year renewal application includes the following three primary tasks. Task 1 on two dimensional neutron transport is divided into (a) single medium searchlight problem (SLP) and (b) two-adjacent half-space SLP. Task 2 on three-dimensional neutron transport covers (a) point source in arbitrary geometry, (b) single medium SLP, and (c) two-adjacent half-space SLP. Task 3 on code verification, includes deterministic and probabilistic codes. The primary aim of the proposed investigation was to provide a suite of comprehensive two- and three-dimensional analytical benchmarks for neutron transport theory applications. This objective has been achieved. The suite of benchmarks in infinite media and the three-dimensional SLP are a relatively comprehensive set of one-group benchmarks for isotropically scattering media. Because of time and resource limitations, the extensions of the benchmarks to include multi-group and anisotropic scattering are not included here. Presently, however, enormous advances in the solution for the planar Green's function in an anisotropically scattering medium have been made and will eventually be implemented in the two- and three-dimensional solutions considered under this grant. Of particular note in this work are the numerical results for the three-dimensional SLP, which have never before been presented. The results presented were made possible only because of the tremendous advances in computing power that have occurred during the past decade

Brain lesion analysis using three-dimensional SPECT imaging

International Nuclear Information System (INIS)

Shibata, Iekado; Onagi, Atsuo; Kuroki, Takao

1995-01-01

A three-headed gamma camera (PRISM 3000) is capable to scan the protocol of early dynamic SPECT and to analyze two radioisotopes at the same time. We have framed three-dimensional brain SPECT images for several brain diseases by using the Application Visualization System (AVS). We carried out volume measurements in brain tumors and/or AVMs by applying this methodology. Thallium-201 and/or 123I-IMP were used for brain SPECT imaging. The dynamic scan protocol was changed in accordance with the given disease. The protocol for brain tumors was derived from a preliminary comparative study with thallium-201 and 123I-IMP that had suggested a disparity in the detection of brain tumors and the differentiation between tumor tissue and normal brain. The three-dimension SPECT image represented the brain tumor or AVM in a striking fashion, and the changes with respect to tumor or AVM after radiosurgery or embolization were understood readily. (author)

Three-dimensional propagation in near-field tomographic X-ray phase retrieval

International Nuclear Information System (INIS)

Ruhlandt, Aike; Salditt, Tim

2016-01-01

An extension of phase retrieval algorithms for near-field X-ray (propagation) imaging to three dimensions is presented, enhancing the quality of the reconstruction by exploiting previously unused three-dimensional consistency constraints. This paper presents an extension of phase retrieval algorithms for near-field X-ray (propagation) imaging to three dimensions, enhancing the quality of the reconstruction by exploiting previously unused three-dimensional consistency constraints. The approach is based on a novel three-dimensional propagator and is derived for the case of optically weak objects. It can be easily implemented in current phase retrieval architectures, is computationally efficient and reduces the need for restrictive prior assumptions, resulting in superior reconstruction quality

Three dimensional reconstruction of tomographic images of the retina

International Nuclear Information System (INIS)

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

2007-01-01

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

Three-dimensional plasmonic chiral tetramers assembled by DNA origami.

Science.gov (United States)

Shen, Xibo; Asenjo-Garcia, Ana; Liu, Qing; Jiang, Qiao; García de Abajo, F Javier; Liu, Na; Ding, Baoquan

2013-05-08

Molecular chemistry offers a unique toolkit to draw inspiration for the design of artificial metamolecules. For a long time, optical circular dichroism has been exclusively the terrain of natural chiral molecules, which exhibit optical activity mainly in the UV spectral range, thus greatly hindering their significance for a broad range of applications. Here we demonstrate that circular dichroism can be generated with artificial plasmonic chiral nanostructures composed of the minimum number of spherical gold nanoparticles required for three-dimensional (3D) chirality. We utilize a rigid addressable DNA origami template to precisely organize four nominally identical gold nanoparticles into a three-dimensional asymmetric tetramer. Because of the chiral structural symmetry and the strong plasmonic resonant coupling between the gold nanoparticles, the 3D plasmonic assemblies undergo different interactions with left and right circularly polarized light, leading to pronounced circular dichroism. Our experimental results agree well with theoretical predictions. The simplicity of our structure geometry and, most importantly, the concept of resorting on biology to produce artificial photonic functionalities open a new pathway to designing smart artificial plasmonic nanostructures for large-scale production of optically active metamaterials.

A computationally efficient simulator for three-dimensional Monte Carlo simulation of ion implantation into complex structures

International Nuclear Information System (INIS)

Li Di; Wang Geng; Chen Yang; Li Lin; Shrivastav, Gaurav; Oak, Stimit; Tasch, Al; Banerjee, Sanjay; Obradovic, Borna

2001-01-01

A physically-based three-dimensional Monte Carlo simulator has been developed within UT-MARLOWE, which is capable of simulating ion implantation into multi-material systems and arbitrary topography. Introducing the third dimension can result in a severe CPU time penalty. In order to minimize this penalty, a three-dimensional trajectory replication algorithm has been developed, implemented and verified. More than two orders of magnitude savings of CPU time have been observed. An unbalanced Octree structure was used to decompose three-dimensional structures. It effectively simplifies the structure, offers a good balance between modeling accuracy and computational efficiency, and allows arbitrary precision of mapping the Octree onto desired structure. Using the well-established and validated physical models in UT-MARLOWE 5.0, this simulator has been extensively verified by comparing the integrated one-dimensional simulation results with secondary ion mass spectroscopy (SIMS). Two options, the typical case and the worst scenario, have been selected to simulate ion implantation into poly-silicon under various scenarios using this simulator: implantation into a random, amorphous network, and implantation into the worst-case channeling condition, into (1 1 0) orientated wafers

Clinical significance of three-dimensional sonohysterography

International Nuclear Information System (INIS)

Lee, Eun Hye; Lee, Mi Hwa; Lee, Chan; Kim, Jong Wook; Shin, Myung Choel

1999-01-01

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.

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.

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 ...

Usefulness Of Three-Dimensional Printing Models for Patients with Stoma Construction

OpenAIRE

Tominaga, Tetsuro; Takagi, Katsunori; Takeshita, Hiroaki; Miyamoto, Tomo; Shimoda, Kozue; Matsuo, Ayano; Matsumoto, Keitaro; Hidaka, Shigekazu; Yamasaki, Naoya; Sawai, Terumitsu; Nagayasu, Takeshi

2016-01-01

The use of patient-specific organ models in three-dimensional printing systems could be helpful for the education of patients and medical students. The aim of this study was to clarify whether the use of patient-specific stoma models is helpful for patient education. From January 2014 to September 2014, 5 patients who underwent colorectal surgery and for whom a temporary or permanent stoma had been created were involved in this study. Three-dimensional stoma models and three-dimensional face ...

Loop expansion in massless three-dimensional QED

International Nuclear Information System (INIS)

Guendelman, E.I.; Radulovic, Z.M.

1983-01-01

It is shown how the loop expansion in massless three-dimensional QED can be made finite, up to three loops, by absorbing the infrared divergences in a gauge-fixing term. The same method removes leading and first subleading singularities to all orders of perturbation theory, and all singularities of the fermion self-energy to four loops

[Application Progress of Three-dimensional Laser Scanning Technology in Medical Surface Mapping].

Science.gov (United States)

Zhang, Yonghong; Hou, He; Han, Yuchuan; Wang, Ning; Zhang, Ying; Zhu, Xianfeng; Wang, Mingshi

2016-04-01

The booming three-dimensional laser scanning technology can efficiently and effectively get spatial three-dimensional coordinates of the detected object surface and reconstruct the image at high speed,high precision and large capacity of information.Non-radiation,non-contact and the ability of visualization make it increasingly popular in three-dimensional surface medical mapping.This paper reviews the applications and developments of three-dimensional laser scanning technology in medical field,especially in stomatology,plastic surgery and orthopedics.Furthermore,the paper also discusses the application prospects in the future as well as the biomedical engineering problems it would encounter with.

Comparison of two three-dimensional cephalometric analysis computer software

OpenAIRE

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

2014-01-01

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

Symmetries, integrals, and three-dimensional reductions of Plebanski's second heavenly equation

International Nuclear Information System (INIS)

Neyzi, F.; Sheftel, M. B.; Yazici, D.

2007-01-01

We study symmetries and conservation laws for Plebanski's second heavenly equation written as a first-order nonlinear evolutionary system which admits a multi-Hamiltonian structure. We construct an optimal system of one-dimensional subalgebras and all inequivalent three-dimensional symmetry reductions of the original four-dimensional system. We consider these two-component evolutionary systems in three dimensions as natural candidates for integrable systems

In-Situ Three-Dimensional Shape Rendering from Strain Values Obtained Through Optical Fiber Sensors

Science.gov (United States)

Chan, Hon Man (Inventor); Parker, Jr., Allen R. (Inventor)

2015-01-01

A method and system for rendering the shape of a multi-core optical fiber or multi-fiber bundle in three-dimensional space in real time based on measured fiber strain data. Three optical fiber cores arc arranged in parallel at 120.degree. intervals about a central axis. A series of longitudinally co-located strain sensor triplets, typically fiber Bragg gratings, are positioned along the length of each fiber at known intervals. A tunable laser interrogates the sensors to detect strain on the fiber cores. Software determines the strain magnitude (.DELTA.L/L) for each fiber at a given triplet, but then applies beam theory to calculate curvature, beading angle and torsion of the fiber bundle, and from there it determines the shape of the fiber in s Cartesian coordinate system by solving a series of ordinary differential equations expanded from the Frenet-Serrat equations. This approach eliminates the need for computationally time-intensive curve-tilting and allows the three-dimensional shape of the optical fiber assembly to be displayed in real-time.

Upper bound on the capacity of constrained three-dimensional codes

DEFF Research Database (Denmark)

Forchhammer, Søren

2000-01-01

An upper bound on the capacity of constrained three-dimensional codes is presented. The bound for two-dimensional codes of Calkin and Wilf (see SIAM Journal of Discrete Mathematics, vol.11, no.1, p.54-60, 1998) was extended to three dimensions by Nagy and Zeger. Both bounds apply to first order s...

Three-dimensional wax patterning of paper fluidic devices.

Science.gov (United States)

Renault, Christophe; Koehne, Jessica; Ricco, Antonio J; Crooks, Richard M

2014-06-17

In this paper we describe a method for three-dimensional wax patterning of microfluidic paper-based analytical devices (μPADs). The method is rooted in the fundamental details of wax transport in paper and provides a simple way to fabricate complex channel architectures such as hemichannels and fully enclosed channels. We show that three-dimensional μPADs can be fabricated with half as much paper by using hemichannels rather than ordinary open channels. We also provide evidence that fully enclosed channels are efficiently isolated from the exterior environment, decreasing contamination risks, simplifying the handling of the device, and slowing evaporation of solvents.

Estimation of three-dimensional radar tracking using modified extended kalman filter

Science.gov (United States)

Aditya, Prima; Apriliani, Erna; Khusnul Arif, Didik; Baihaqi, Komar

2018-03-01

Kalman filter is an estimation method by combining data and mathematical models then developed be extended Kalman filter to handle nonlinear systems. Three-dimensional radar tracking is one of example of nonlinear system. In this paper developed a modification method of extended Kalman filter from the direct decline of the three-dimensional radar tracking case. The development of this filter algorithm can solve the three-dimensional radar measurements in the case proposed in this case the target measured by radar with distance r, azimuth angle θ, and the elevation angle ϕ. Artificial covariance and mean adjusted directly on the three-dimensional radar system. Simulations result show that the proposed formulation is effective in the calculation of nonlinear measurement compared with extended Kalman filter with the value error at 0.77% until 1.15%.

Three dimensional characterization and archiving system

International Nuclear Information System (INIS)

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

1996-01-01

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

Multi-GPU hybrid programming accelerated three-dimensional phase-field model in binary alloy

Directory of Open Access Journals (Sweden)

Changsheng Zhu

2018-03-01

Full Text Available In the process of dendritic growth simulation, the computational efficiency and the problem scales have extremely important influence on simulation efficiency of three-dimensional phase-field model. Thus, seeking for high performance calculation method to improve the computational efficiency and to expand the problem scales has a great significance to the research of microstructure of the material. A high performance calculation method based on MPI+CUDA hybrid programming model is introduced. Multi-GPU is used to implement quantitative numerical simulations of three-dimensional phase-field model in binary alloy under the condition of multi-physical processes coupling. The acceleration effect of different GPU nodes on different calculation scales is explored. On the foundation of multi-GPU calculation model that has been introduced, two optimization schemes, Non-blocking communication optimization and overlap of MPI and GPU computing optimization, are proposed. The results of two optimization schemes and basic multi-GPU model are compared. The calculation results show that the use of multi-GPU calculation model can improve the computational efficiency of three-dimensional phase-field obviously, which is 13 times to single GPU, and the problem scales have been expanded to 8193. The feasibility of two optimization schemes is shown, and the overlap of MPI and GPU computing optimization has better performance, which is 1.7 times to basic multi-GPU model, when 21 GPUs are used.

Three-Dimensional Structure Determination of Botulinum Toxin

National Research Council Canada - National Science Library

Stevens, Ray

1997-01-01

...) Based on the structure of the neurotoxin, understand the toxins mechanism of action. We have accomplished the first goal of determining the three-dimensional structure of the 150 kD botulinum neurotoxin serotype...

Three-Dimensional Structure Determination of Botulinum Toxin

National Research Council Canada - National Science Library

Stevens, Ray

1998-01-01

...) Based on the structure of the neurotoxin, understand the toxins mechanism of action. We have accomplished the first goal of determining the three-dimensional structure of the 150 kD botulinum neurotoxin serotype...

Time-dependent gravitating solitons in five dimensional warped space-times

CERN Document Server

Giovannini, Massimo

2007-01-01

Time-dependent soliton solutions are explicitly derived in a five-dimensional theory endowed with one (warped) extra-dimension. Some of the obtained geometries, everywhere well defined and technically regular, smoothly interpolate between two five-dimensional anti-de Sitter space-times for fixed value of the conformal time coordinate. Time dependent solutions containing both topological and non-topological sectors are also obtained. Supplementary degrees of freedom can be also included and, in this case, the resulting multi-soliton solutions may describe time-dependent kink-antikink systems.

Three-dimensional display improves observer speed and accuracy

International Nuclear Information System (INIS)

Nelson, J.A.; Rowberg, A.H.; Kuyper, S.; Choi, H.S.

1989-01-01

In an effort to evaluate the potential cost-effectiveness of three-dimensional (3D) display equipment, we compared the speed and accuracy of experienced radiologists identifying in sliced uppercase letters from CT scans with 2D and pseudo-3D display. CT scans of six capital letters were obtained and printed as a 2D display or as a synthesized pseudo-3D display (Pixar). Six observes performed a timed identification task. Radiologists read the 3D display an average of 16 times faster than the 2D, and the average error rate of 2/6 (± 0.6/6) for 2D interpretations was totally eliminated. This degree of improvement in speed and accuracy suggests that the expense of 3D display may be cost-effective in a defined clinical setting

Three-dimensional MRI of the glenoid labrum

International Nuclear Information System (INIS)

Loehr, S.P.; Pope, T.L. Jr.; Martin, D.F.; Link, K.M.; Monu, J.U.V.; Hunter, M.; Reboussin, D.

1995-01-01

The objective of this study was to assess the accuracy of three-dimensional (3D) magnetic resonance imaging (MRI) reformation in the evaluation of tears of the glenoid labrum complex (GLC). Fifty-five shoulders were evaluated by MRI using standard spin-echo sequences. Gradient-refocused-echo axial projections were used to assess the GLC on the two-dimensional (2D) studies. Three-dimensional Fourier transform multiplanar gradient-recalled imaging with a resolution of 0.7 mm was also performed in all patients. Independent analyses of the anterior and posterior labra were performed in a blinded manner for both the 2D and 3D studies by three experienced musculoskeletal radiologists. Observations of the imaging studies were compared with the videoarthroscopic findings. The appearance of the GLC was rated on a scale of 0 to 4 (0-2=normal, 3, 4=abnormal or torn). The diagnostic confidence was averaged from the three reader's scores. Anterior labral tears were effectively detected with sensitivities of 89% and 96% and specificities of 96% and 100% (P<0.0001) for the 2D and 3D studies, respectively. For posterior labral tears, the sensitivity and specificity of the 2D method were 47% and 98%, respectively. The sensitivity and specificity of the 3D volume sequence were 53% and 98%, respectively. The lower sensitivity of both imaging methods for detecting posterior labral tears may be influenced by the smaller number (n=5) of arthroscopically confirmed cases in our study and reflects the difficulty of visualizing the posteroinferior borders of the GLC with present MRI techniques. (orig.)

The Group Evacuation Behavior Based on Fire Effect in the Complicated Three-Dimensional Space

Directory of Open Access Journals (Sweden)

Jun Hu

2014-01-01

Full Text Available In order to effectively depict the group evacuation behavior in the complicated three-dimensional space, a novel pedestrian flow model is proposed with three-dimensional cellular automata. In this model the calculation methods of floor field and fire gain are elaborated at first, and the transition gain of target position at the next moment is defined. Then, in consideration of pedestrian intimacy and velocity change, the group evacuation strategy and evolution rules are given. Finally, the experiments were conducted with the simulation platform to study the relationships of evacuation time, pedestrian density, average system velocity, and smoke spreading velocity. The results had shown that large-scale group evacuation should be avoided, and in case of large pedestrian density, the shortest route of evacuation strategy would extend system evacuation time.

Three-dimensional organization of vestibular related eye movements to rotational motion in pigeons

Science.gov (United States)

Dickman, J. D.; Beyer, M.; Hess, B. J.

2000-01-01

During rotational motions, compensatory eye movement adjustments must continually occur in order to maintain objects of visual interest as stable images on the retina. In the present study, the three-dimensional organization of the vestibulo-ocular reflex in pigeons was quantitatively examined. Rotations about different head axes produced horizontal, vertical, and torsional eye movements, whose component magnitude was dependent upon the cosine of the stimulus axis relative to the animal's visual axis. Thus, the three-dimensional organization of the VOR in pigeons appears to be compensatory for any direction of head rotation. Frequency responses of the horizontal, vertical, and torsional slow phase components exhibited high pass filter properties with dominant time constants of approximately 3 s.

Infrared magneto-spectroscopy of two-dimensional and three-dimensional massless fermions: A comparison

Energy Technology Data Exchange (ETDEWEB)

Orlita, M., E-mail: milan.orlita@lncmi.cnrs.fr [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 38042 Grenoble (France); Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic); Faugeras, C.; Barra, A.-L.; Martinez, G.; Potemski, M. [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 38042 Grenoble (France); Basko, D. M. [LPMMC UMR 5493, Université Grenoble 1/CNRS, B.P. 166, 38042 Grenoble (France); Zholudev, M. S. [Laboratoire Charles Coulomb (L2C), UMR CNRS 5221, GIS-TERALAB, Université Montpellier II, 34095 Montpellier (France); Institute for Physics of Microstructures, RAS, Nizhny Novgorod GSP-105 603950 (Russian Federation); Teppe, F.; Knap, W. [Laboratoire Charles Coulomb (L2C), UMR CNRS 5221, GIS-TERALAB, Université Montpellier II, 34095 Montpellier (France); Gavrilenko, V. I. [Institute for Physics of Microstructures, RAS, Nizhny Novgorod GSP-105 603950 (Russian Federation); Mikhailov, N. N.; Dvoretskii, S. A. [A.V. Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Neugebauer, P. [Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart (Germany); Berger, C. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Institut Néel/CNRS-UJF BP 166, F-38042 Grenoble Cedex 9 (France); Heer, W. A. de [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2015-03-21

Here, we report on a magneto-optical study of two distinct systems hosting massless fermions—two-dimensional graphene and three-dimensional HgCdTe tuned to the zero band gap condition at the point of the semiconductor-to-semimetal topological transition. Both materials exhibit, in the quantum regime, a fairly rich magneto-optical response, which is composed from a series of intra- and interband inter-Landau level resonances with for massless fermions typical √(B) dependence. The impact of the system's dimensionality and of the strength of the spin-orbit interaction on the optical response is also discussed.

Usefulness and limitations of transthoracic echocardiography in heart transplantation recipients

Directory of Open Access Journals (Sweden)

Galderisi Maurizio

2008-01-01

Full Text Available Abstract Transthoracic echocardiography is a primary non-invasive modality for investigation of heart transplant recipients. It is a versatile tool which provides comprehensive information about cardiac structure and function. Echocardiographic examinations can be easily performed at the bedside and serially repeated without any patient's discomfort. This review highlights the usefulness of Doppler echocardiography in the assessment of left ventricular and right ventricular systolic and diastolic function, of left ventricular mass, valvular heart disease, pulmonary arterial hypertension and pericardial effusion in heart transplant recipients. The main experiences performed by either standard Doppler echocardiography and new high-tech ultrasound technologies are summarised, pointing out advantages and limitations of the described techniques in diagnosing acute allograft rejection and cardiac graft vasculopathy. Despite the sustained efforts of echocardiographic technique in predicting the biopsy state, endocardial myocardial biopsies are still regarded as the gold standard for detection of acute allograft rejection. Conversely, stress echocardiography is able to identify accurately cardiac graft vasculopathy and has a recognised prognostic in this clinical setting. A normal stress-echo justifies postponement of invasive studies. Another use of transthoracic echocardiography is the monitorisation and the visualisation of the catheter during the performance of endomyocardial biopsy. Bedside stress echocardiography is even useful to select appropriately heart donors with brain death. The ultrasound monitoring is simple and effective for monitoring a safe performance of biopsy procedures.

Three dimensional system integration

CERN Document Server

Papanikolaou, Antonis; Radojcic, Riko

2010-01-01

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

Turbulence in Three Dimensional Simulations of Magnetopause Reconnection

Science.gov (United States)

Drake, J. F.; Price, L.; Swisdak, M.; Burch, J. L.; Cassak, P.; Dahlin, J. T.; Ergun, R.

2017-12-01

We present two- and three-dimensional particle-in-cell simulations of the 16 October 2015 MMS magnetopause reconnection event. While the two-dimensional simulation is laminar, turbulence develops at both the x-line and along the magnetic separatrices in the three-dimensional simulation. This turbulence is electromagnetic in nature, is characterized by a wavevector k given by kρ e ˜(m_e/m_i)0.25 with ρ e the electron Larmor radius, and appears to have the ion pressure gradient as its source of free energy. Taken together, these results suggest the instability is a variant of the lower-hybrid drift instability. The turbulence produces electric field fluctuations in the out-of-plane direction (the direction of the reconnection electric field) with an amplitude of around ± 10 mV/m, which is much greater than the reconnection electric field of around 0.1 mV/m. Such large values of the out-of-plane electric field have been identified in the MMS data. The turbulence in the simulation controls the scale lengths of the density profile and current layers in asymmetric reconnection, driving them closer to √ {ρ eρ_i } than the ρ e or de scalings seen in 2D reconnection simulations, where de is the electron inertial length. The turbulence is strong enough to make the magnetic field around the reconnection island chaotic and produces both anomalous resistivity and anomalous viscosity. Each contribute significantly to breaking the frozen-in condition in the electron diffusion region. The crescent-shaped features in velocity space seen both in MMS observations and in two-dimensional simulations survive, even in the turbulent environment of the three-dimensional system. We compare and contrast these results to a three-dimensional simulation of the 8 December 2015 MMS magnetopause reconnection event in which the reconnecting and out-of-plane guide fields are comparable. LHDI is still present in this event, although its appearance is modified by the presence of the guide

Three-dimensional polarization states of monochromatic light fields.

Science.gov (United States)

Azzam, R M A

2011-11-01

The 3×1 generalized Jones vectors (GJVs) [E(x) E(y) E(z)](t) (t indicates the transpose) that describe the linear, circular, and elliptical polarization states of an arbitrary three-dimensional (3-D) monochromatic light field are determined in terms of the geometrical parameters of the 3-D vibration of the time-harmonic electric field. In three dimensions, there are as many distinct linear polarization states as there are points on the surface of a hemisphere, and the number of distinct 3-D circular polarization states equals that of all two-dimensional (2-D) polarization states on the Poincaré sphere, of which only two are circular states. The subset of 3-D polarization states that results from the superposition of three mutually orthogonal x, y, and z field components of equal amplitude is considered as a function of their relative phases. Interesting contours of equal ellipticity and equal inclination of the normal to the polarization ellipse with respect to the x axis are obtained in 2-D phase space. Finally, the 3×3 generalized Jones calculus, in which elastic scattering (e.g., by a nano-object in the near field) is characterized by the 3-D linear transformation E(s)=T E(i), is briefly introduced. In such a matrix transformation, E(i) and E(s) are the 3×1 GJVs of the incident and scattered waves and T is the 3×3 generalized Jones matrix of the scatterer at a given frequency and for given directions of incidence and scattering.

Two- and three-dimensional CT evaluation of sacral and pelvic anomalies

International Nuclear Information System (INIS)

Kuhlman, J.E.; Fishman, E.K.; Magid, D.

1988-01-01

Pelvic anomalies are difficult to evaluate with standard techniques. Detailed knowledge of the existing pelvic structures and musculature is essential for successful repair. The authors evaluated 12 patients with complex malformations of the pelvis using two- and three-dimensional imaging. The anomalies included bladder exstrophy (n = 4), cloacal exstrophy (n = 1), duplicated and absent sacrum (n = 3), myelomeningoceles (n = 2), and diastrophic dwarfism (n = 2). The two-dimensional images consisted of sequential coronal and sagittal reconstructions that could be reviewed dynamically on screen. Three-dimensional images were generated on the Pixar imaging computer with use of volumetric rendering. Two- and three-dimensional CT proved complementary in the evaluation of pelvic anomalies, providing optimal information from transaxial CT data

Two-dimensional phononic crystals with time-varying properties: a multiple scattering analysis

International Nuclear Information System (INIS)

Wright, D W; Cobbold, R S C

2010-01-01

Multiple scattering theory is a versatile two- and three-dimensional method for characterizing the acoustic wave transmission through many scatterers. It provides analytical solutions to wave propagation in scattering structures, and its computational complexity grows logarithmically with the number of scatterers. In this paper we show how the 2D method can be adapted to include the effects of time-varying material parameters. Specifically, a new T-matrix is defined to include the effects of frequency modulation that occurs in time-varying phononic crystals. Solutions were verified against finite difference time domain (FDTD) simulations and showed excellent agreement. This new method enables fast characterization of time-varying phononic crystals without the need to resort to lengthy FDTD simulations. Also, the method of combining T-matrices to form the T-supermatrix remains unchanged provided that the new matrix definitions are used. The method is quite compatible with existing implementations of multiple scattering theory and could be readily extended to three-dimensional multiple scattering theory

The advantages of live/real time three-dimensional transesophageal echocardiography during assessments of pulmonary stenosis.

Science.gov (United States)

Kemaloğlu Öz, Tuğba; Özpamuk Karadeniz, Fatma; Akyüz, Şükrü; Ünal Dayı, Şennur; Esen Zencirci, Aycan; Atasoy, Işıl; Ösken, Altuğ; Eren, Mehmet

2016-04-01

This report sought to compare live/real-time three-dimensional transesophageal echocardiography (3D-TEE) with two-dimensional transesophageal echocardiography (2D-TEE) and to determine whether there are advantages to using 3D-TEE on patients with pulmonary stenosis (PS). Sixteen consecutive adult patients (50 % male and 50 % female; mean age 33 ± 13.4 years) with PS and indications of TEE were prospectively enrolled in this study. Following this, initial 2D-TEE and 3D-TEE examinations were performed, and 3D-TEE images were analyzed using an off-line Q-lab software system. Finally, the 2D-TEE and 3D-TEE findings were compared. In the present study, 3D-TEE allowed us to obtain the en face views of pulmonary valves (PVs) in all but one patient. While this patient was without a PV due to a previous tetralogy of Fallot operation, we could detect the type of PV in the other 15 (93.7 %) patients by using 3D-TEE. Due to poor image quality, the most stenotic area was not measurable in only one (6.2 %) of the patients. In eight (50 %) of the patients, severity and localization of stenosis were more precisely determined with 3DTEE than with 2D-TEE. The PVs' maximal annulus dimensions were found to be significantly larger when they were measured using 3D modalities. This study provides evidence of the incremental value of using 3D-TEE rather than 2D-TEE during assessments of PS, specifically in cases where special conditions (pregnancy, pulmonary regurgitation, and concomitant atrial septal defects) cause recordings of the transvalvular peak gradient to be inaccurate. Therefore, 3D-TEE should be used as a complementary imaging tool to 2D-TEE during routine echocardiographic examinations.

Self-assembled three-dimensional and compressible interdigitated thin-film supercapacitors and batteries

Science.gov (United States)

Nyström, Gustav; Marais, Andrew; Karabulut, Erdem; Wågberg, Lars; Cui, Yi; Hamedi, Mahiar M.

2015-01-01

Traditional thin-film energy-storage devices consist of stacked layers of active films on two-dimensional substrates and do not exploit the third dimension. Fully three-dimensional thin-film devices would allow energy storage in bulk materials with arbitrary form factors and with mechanical properties unique to bulk materials such as compressibility. Here we show three-dimensional energy-storage devices based on layer-by-layer self-assembly of interdigitated thin films on the surface of an open-cell aerogel substrate. We demonstrate a reversibly compressible three-dimensional supercapacitor with carbon nanotube electrodes and a three-dimensional hybrid battery with a copper hexacyanoferrate ion intercalating cathode and a carbon nanotube anode. The three-dimensional supercapacitor shows stable operation over 400 cycles with a capacitance of 25 F g−1 and is fully functional even at compressions up to 75%. Our results demonstrate that layer-by-layer self-assembly inside aerogels is a rapid, precise and scalable route for building high-surface-area 3D thin-film devices. PMID:26021485

A retrospective and prospective survey of three-dimensional transport calculations

International Nuclear Information System (INIS)

Nakahara, Yasuaki

1985-01-01

A retrospective survey is made on the three-dimensional radiation transport calculations. Introduction is given to computer codes based on the distinctive numerical methods such as the Monte Carlo, Direct Integration, Ssub(n) and Finite Element Methods to solve the three-dimensional transport equations. Prospective discussions are made on pros and cons of these methods. (author)

Early orthognathic surgery with three-dimensional image simulation during presurgical orthodontics in adults.

Science.gov (United States)

Kang, Sang-Hoon; Kim, Moon-Key; Park, Sun-Yeon; Lee, Ji-Yeon; Park, Wonse; Lee, Sang-Hwy

2011-03-01

To correct dentofacial deformities, three-dimensional skeletal analysis and computerized orthognathic surgery simulation are used to facilitate accurate diagnoses and surgical plans. Computed tomography imaging of dental occlusion can inform three-dimensional facial analyses and orthognathic surgical simulations. Furthermore, three-dimensional laser scans of a cast model of the predetermined postoperative dental occlusion can be used to increase the accuracy of the preoperative surgical simulation. In this study, we prepared cast models of planned postoperative dental occlusions from 12 patients diagnosed with skeletal class III malocclusions with mandibular prognathism and facial asymmetry that had planned to undergo bimaxillary orthognathic surgery during preoperative orthodontic treatment. The data from three-dimensional laser scans of the cast models were used in three-dimensional surgical simulations. Early orthognathic surgeries were performed based on three-dimensional image simulations using the cast images in several presurgical orthodontic states in which teeth alignment, leveling, and space closure were incomplete. After postoperative orthodontic treatments, intraoral examinations revealed that no patient had a posterior open bite or space. The two-dimensional and three-dimensional skeletal analyses showed that no mandibular deviations occurred between the immediate and final postoperative states of orthodontic treatment. These results showed that early orthognathic surgery with three-dimensional computerized simulations based on cast models of predetermined postoperative dental occlusions could provide early correction of facial deformities and improved efficacy of preoperative orthodontic treatment. This approach can reduce the decompensation treatment period of the presurgical orthodontics and contribute to efficient postoperative orthodontic treatments.

The confusion effect when attacking simulated three-dimensional starling flocks.

Science.gov (United States)

Hogan, Benedict G; Hildenbrandt, Hanno; Scott-Samuel, Nicholas E; Cuthill, Innes C; Hemelrijk, Charlotte K

2017-01-01

The confusion effect describes the phenomenon of decreasing predator attack success with increasing prey group size. However, there is a paucity of research into the influence of this effect in coherent groups, such as flocks of European starlings ( Sturnus vulgaris ). Here, for the first time, we use a computer game style experiment to investigate the confusion effect in three dimensions. To date, computerized studies on the confusion effect have used two-dimensional simulations with simplistic prey movement and dynamics. Our experiment is the first investigation of the effects of flock size and density on the ability of a (human) predator to track and capture a target starling in a realistically simulated three-dimensional flock of starlings. In line with the predictions of the confusion effect, modelled starlings appear to be safer from predation in larger and denser flocks. This finding lends credence to previous suggestions that starling flocks have anti-predator benefits and, more generally, it suggests that active increases in density in animal groups in response to predation may increase the effectiveness of the confusion effect.

Three-dimensional characterization of stress corrosion cracks

DEFF Research Database (Denmark)

Lozano-Perez, S.; Rodrigo, P.; Gontard, Lionel Cervera

2011-01-01

the best spatial resolution. To illustrate the power of these techniques, different parts of dominant stress corrosion cracks in Ni-alloys and stainless steels have been reconstructed in 3D. All relevant microstructural features can now be studied in detail and its relative orientation respect......Understanding crack propagation and initiation is fundamental if stress corrosion cracking (SCC) mechanisms are to be understood. However, cracking is a three-dimensional (3D) phenomenon and most characterization techniques are restricted to two-dimensional (2D) observations. In order to overcome...

Experimental investigation of three-dimensional flow instabilities in a rotating lid-driven cavity

DEFF Research Database (Denmark)

Sørensen, Jens Nørkær; Naumov, I.; Mikkelsen, Robert Flemming

2006-01-01

liquid. For the first time the onset of three-dimensionality and transition are analysed by combining the high spatial resolution of Particle Image Velocimetry (PIV) and the temporal accuracy of Laser Doppler Anemometry (LDA). A detailed mapping of the transition from steady and axisymmetric flow...

Issues in measure-preserving three dimensional flow integrators: Self-adjointness, reversibility, and non-uniform time stepping

International Nuclear Information System (INIS)

Finn, John M.

2015-01-01

Properties of integration schemes for solenoidal fields in three dimensions are studied, with a focus on integrating magnetic field lines in a plasma using adaptive time stepping. It is shown that implicit midpoint (IM) and a scheme we call three-dimensional leapfrog (LF) can do a good job (in the sense of preserving KAM tori) of integrating fields that are reversible, or (for LF) have a “special divergence-free” (SDF) property. We review the notion of a self-adjoint scheme, showing that such schemes are at least second order accurate and can always be formed by composing an arbitrary scheme with its adjoint. We also review the concept of reversibility, showing that a reversible but not exactly volume-preserving scheme can lead to a fractal invariant measure in a chaotic region, although this property may not often be observable. We also show numerical results indicating that the IM and LF schemes can fail to preserve KAM tori when the reversibility property (and the SDF property for LF) of the field is broken. We discuss extensions to measure preserving flows, the integration of magnetic field lines in a plasma and the integration of rays for several plasma waves. The main new result of this paper relates to non-uniform time stepping for volume-preserving flows. We investigate two potential schemes, both based on the general method of Feng and Shang [Numer. Math. 71, 451 (1995)], in which the flow is integrated in split time steps, each Hamiltonian in two dimensions. The first scheme is an extension of the method of extended phase space, a well-proven method of symplectic integration with non-uniform time steps. This method is found not to work, and an explanation is given. The second method investigated is a method based on transformation to canonical variables for the two split-step Hamiltonian systems. This method, which is related to the method of non-canonical generating functions of Richardson and Finn [Plasma Phys. Controlled Fusion 54, 014004 (2012

Three-dimensional simulations of Bingham plastic flows with the multiple-relaxation-time lattice Boltzmann model

Directory of Open Access Journals (Sweden)

Song-Gui Chen

2016-01-01

Full Text Available This paper presents a three-dimensional (3D parallel multiple-relaxation-time lattice Boltzmann model (MRT-LBM for Bingham plastics which overcomes numerical instabilities in the simulation of non-Newtonian fluids for the Bhatnagar–Gross–Krook (BGK model. The MRT-LBM and several related mathematical models are briefly described. Papanastasiou’s modified model is incorporated for better numerical stability. The impact of the relaxation parameters of the model is studied in detail. The MRT-LBM is then validated through a benchmark problem: a 3D steady Poiseuille flow. The results from the numerical simulations are consistent with those derived analytically which indicates that the MRT-LBM effectively simulates Bingham fluids but with better stability. A parallel MRT-LBM framework is introduced, and the parallel efficiency is tested through a simple case. The MRT-LBM is shown to be appropriate for parallel implementation and to have high efficiency. Finally, a Bingham fluid flowing past a square-based prism with a fixed sphere is simulated. It is found the drag coefficient is a function of both Reynolds number (Re and Bingham number (Bn. These results reveal the flow behavior of Bingham plastics.

A versatile atomic force microscope for three-dimensional nanomanipulation and nanoassembly

International Nuclear Information System (INIS)

Xie Hui; Haliyo, Dogan Sinan; Regnier, Stephane

2009-01-01

A conventional atomic force microscope (AFM) has been successfully applied to manipulating nanoparticles (zero-dimensional), nanowires (one-dimensional) or nanotubes (one- or two-dimensional) by widely used pushing or pulling operations on a single surface. However, pick-and-place nanomanipulation in air is still a challenge. In this research, a modified AFM, called a three-dimensional (3D) manipulation force microscope (3DMFM), was developed to realize 3D nanomanipulation in air. This system consists of two individually actuated cantilevers with protruding tips that are facing each other, constructing a nanotweezer for the pick-and-place nanomanipulation. Before manipulation, one of the cantilevers is employed to position nano-objects and locate the tip of the other cantilever by image scanning. During the manipulation, these two cantilevers work collaboratively as a nanotweezer to grasp, transport and place the nano-objects with real-time force sensing. The manipulation capabilities of the nanotweezer were demonstrated by grabbing and manipulating silicon nanowires to build 3D nanowire crosses. 3D nanomanipulation and nanoassembly performed in air could become feasible through this newly developed 3DMFM.

Three-dimensional particle tracking velocimetry using dynamic vision sensors

Science.gov (United States)

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.

Dynamic three-dimensional display of common congenital cardiac defects from reconstruction of two-dimensional echocardiographic images.

Science.gov (United States)

Hsieh, K S; Lin, C C; Liu, W S; Chen, F L

1996-01-01

Two-dimensional echocardiography had long been a standard diagnostic modality for congenital heart disease. Further attempts of three-dimensional reconstruction using two-dimensional echocardiographic images to visualize stereotypic structure of cardiac lesions have been successful only recently. So far only very few studies have been done to display three-dimensional anatomy of the heart through two-dimensional image acquisition because such complex procedures were involved. This study introduced a recently developed image acquisition and processing system for dynamic three-dimensional visualization of various congenital cardiac lesions. From December 1994 to April 1995, 35 cases were selected in the Echo Laboratory here from about 3000 Echo examinations completed. Each image was acquired on-line with specially designed high resolution image grazmber with EKG and respiratory gating technique. Off-line image processing using a window-architectured interactive software package includes construction of 2-D ehcocardiographic pixel to 3-D "voxel" with conversion of orthogonal to rotatory axial system, interpolation, extraction of region of interest, segmentation, shading and, finally, 3D rendering. Three-dimensional anatomy of various congenital cardiac defects was shown, including four cases with ventricular septal defects, two cases with atrial septal defects, and two cases with aortic stenosis. Dynamic reconstruction of a "beating heart" is recorded as vedio tape with video interface. The potential application of 3D display of the reconstruction from 2D echocardiographic images for the diagnosis of various congenital heart defects has been shown. The 3D display was able to improve the diagnostic ability of echocardiography, and clear-cut display of the various congenital cardiac defects and vavular stenosis could be demonstrated. Reinforcement of current techniques will expand future application of 3D display of conventional 2D images.

Extinction maps toward the Milky Way bulge: Two-dimensional and three-dimensional tests with apogee

Energy Technology Data Exchange (ETDEWEB)

Schultheis, M. [Université de Nice Sophia-Antipolis, CNRS, Observatoire de Côte d' Azur, Laboratoire Lagrange, 06304 Nice Cedex 4 (France); Zasowski, G. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Allende Prieto, C. [Instituto de Astrofísica de Canarias, Calle Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Anders, F.; Chiappini, C. [Leibniz-Institut für Astrophysik Potsdam (AIP), D-14482 Potsdam (Germany); Beaton, R. L.; García Pérez, A. E.; Majewski, S. R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Beers, T. C. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Bizyaev, D. [Apache Point Observatory, Sunspot, NM 88349 (United States); Frinchaboy, P. M. [Department of Physics and Astronomy, Texas Christian University, TCU Box 298840, Fort Worth, TX 76129 (United States); Ge, J. [Astronomy Department, University of Florida, Gainesville, FL 32611 (United States); Hearty, F.; Schneider, D. P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Holtzman, J. [New Mexico State University, Las Cruces, NM 88003 (United States); Muna, D. [Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States); Nidever, D. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Shetrone, M., E-mail: mathias.schultheis@oca.eu, E-mail: gail.zasowski@gmail.com [McDonald Observatory, The University of Texas at Austin, Austin, TX 78712 (United States)

2014-07-01

Galactic interstellar extinction maps are powerful and necessary tools for Milky Way structure and stellar population analyses, particularly toward the heavily reddened bulge and in the midplane. However, due to the difficulty of obtaining reliable extinction measures and distances for a large number of stars that are independent of these maps, tests of their accuracy and systematics have been limited. Our goal is to assess a variety of photometric stellar extinction estimates, including both two-dimensional and three-dimensional extinction maps, using independent extinction measures based on a large spectroscopic sample of stars toward the Milky Way bulge. We employ stellar atmospheric parameters derived from high-resolution H-band Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra, combined with theoretical stellar isochrones, to calculate line-of-sight extinction and distances for a sample of more than 2400 giants toward the Milky Way bulge. We compare these extinction values to those predicted by individual near-IR and near+mid-IR stellar colors, two-dimensional bulge extinction maps, and three-dimensional extinction maps. The long baseline, near+mid-IR stellar colors are, on average, the most accurate predictors of the APOGEE extinction estimates, and the two-dimensional and three-dimensional extinction maps derived from different stellar populations along different sightlines show varying degrees of reliability. We present the results of all of the comparisons and discuss reasons for the observed discrepancies. We also demonstrate how the particular stellar atmospheric models adopted can have a strong impact on this type of analysis, and discuss related caveats.

Extinction maps toward the Milky Way bulge: Two-dimensional and three-dimensional tests with apogee

International Nuclear Information System (INIS)

Schultheis, M.; Zasowski, G.; Allende Prieto, C.; Anders, F.; Chiappini, C.; Beaton, R. L.; García Pérez, A. E.; Majewski, S. R.; Beers, T. C.; Bizyaev, D.; Frinchaboy, P. M.; Ge, J.; Hearty, F.; Schneider, D. P.; Holtzman, J.; Muna, D.; Nidever, D.; Shetrone, M.

2014-01-01

Galactic interstellar extinction maps are powerful and necessary tools for Milky Way structure and stellar population analyses, particularly toward the heavily reddened bulge and in the midplane. However, due to the difficulty of obtaining reliable extinction measures and distances for a large number of stars that are independent of these maps, tests of their accuracy and systematics have been limited. Our goal is to assess a variety of photometric stellar extinction estimates, including both two-dimensional and three-dimensional extinction maps, using independent extinction measures based on a large spectroscopic sample of stars toward the Milky Way bulge. We employ stellar atmospheric parameters derived from high-resolution H-band Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra, combined with theoretical stellar isochrones, to calculate line-of-sight extinction and distances for a sample of more than 2400 giants toward the Milky Way bulge. We compare these extinction values to those predicted by individual near-IR and near+mid-IR stellar colors, two-dimensional bulge extinction maps, and three-dimensional extinction maps. The long baseline, near+mid-IR stellar colors are, on average, the most accurate predictors of the APOGEE extinction estimates, and the two-dimensional and three-dimensional extinction maps derived from different stellar populations along different sightlines show varying degrees of reliability. We present the results of all of the comparisons and discuss reasons for the observed discrepancies. We also demonstrate how the particular stellar atmospheric models adopted can have a strong impact on this type of analysis, and discuss related caveats.