Benchmarking the pseudopotential and fixed-node approximations in diffusion Monte Carlo calculations of molecules and solids

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

Nazarov, Roman; Shulenburger, Luke; Morales, Miguel A.

We performed diffusion Monte Carlo (DMC) calculations of the spectroscopic properties of a large set of molecules, assessing the effect of different approximations. In systems containing elements with large atomic numbers, we show that the errors associated with the use of nonlocal mean-field-based pseudopotentials in DMC calculations can be significant and may surpass the fixed-node error. In conclusion, we suggest practical guidelines for reducing these pseudopotential errors, which allow us to obtain DMC-computed spectroscopic parameters of molecules and equation of state properties of solids in excellent agreement with experiment.

An assumed-stress hybrid 4-node shell element with drilling degrees of freedom

NASA Technical Reports Server (NTRS)

Aminpour, M. A.

1992-01-01

An assumed-stress hybrid/mixed 4-node quadrilateral shell element is introduced that alleviates most of the deficiencies associated with such elements. The formulation of the element is based on the assumed-stress hybrid/mixed method using the Hellinger-Reissner variational principle. The membrane part of the element has 12 degrees of freedom including rotational or 'drilling' degrees of freedom at the nodes. The bending part of the element also has 12 degrees of freedom. The bending part of the element uses the Reissner-Mindlin plate theory which takes into account the transverse shear contributions. The element formulation is derived from an 8-node isoparametric element by expressing the midside displacement degrees of freedom in terms of displacement and rotational degrees of freedom at corner nodes. The element passes the patch test, is nearly insensitive to mesh distortion, does not 'lock', possesses the desirable invariance properties, has no hidden spurious modes, and for the majority of test cases used in this paper produces more accurate results than the other elements employed herein for comparison.

Placing three-dimensional isoparametric elements into NASTRAN. [alterations in matrix assembly to simplify generation of higher order elements

NASA Technical Reports Server (NTRS)

Newman, M. B.; Filstrup, A. W.

1973-01-01

Linear (8 node), parabolic (20 node), cubic (32 node) and mixed (some edges linear, some parabolic and some cubic) have been inserted into NASTRAN, level 15.1. First the dummy element feature was used to check out the stiffness matrix generation routines for the linear element in NASTRAN. Then, the necessary modules of NASTRAN were modified to include the new family of elements. The matrix assembly was changed so that the stiffness matrix of each isoparametric element is only generated once as the time to generate these higher order elements tends to be much longer than the other elements in NASTRAN. This paper presents some of the experiences and difficulties of inserting a new element or family of elements into NASTRAN.

Direct formulation of a 4-node hybrid shell element with rotational degrees of freedom

NASA Technical Reports Server (NTRS)

Aminpour, Mohammad A.

1990-01-01

A simple 4-node assumed-stress hybrid quadrilateral shell element with rotational or drilling degrees of freedom is formulated. The element formulation is based directly on a 4-node element. This direct formulation requires fewer computations than a similar element that is derived from an internal 8-node isoparametric element in which the midside degrees of freedom are eliminated in favor of rotational degree of freedom at the corner nodes. The formulation is based on the principle of minimum complementary energy. The membrane part of the element has 12 degrees of freedom including rotational degrees of freedom. The bending part of the element also has 12 degrees of freedom. The bending part of the quadratic variations for both in-plane and out-of-plane displacement fields and linear variations for both in-plane and out-of-plane rotation fields are assumed along the edges of the element. The element Cartesian-coordinate system is chosen such as to make the stress field invariant with respect to node numbering. The membrane part of the stress field is based on a 9-parameter equilibrating stress field, while the bending part is based on a 13-parameter equilibrating stress field. The element passes the patch test, is nearly insensitive to mesh distortion, does not lock, possesses the desirable invariance properties, has no spurious modes, and produces accurate and reliable results.

A New Axi-Symmetric Element for Thin Walled Structures

NASA Astrophysics Data System (ADS)

Cardoso, Rui P. R.; Yoon, Jeong Whan; Dick, Robert E.

2010-06-01

A new axi-symmetric finite element for sheet metal forming applications is presented in this work. It uses the solid-shell element's concept with only a single element layer and multiple integration points along the thickness direction. The cross section of the element is composed of four nodes with two degrees of freedom each. The proposed formulation overcomes major locking pathologies including transverse shear locking, Poisson's locking and volumetric locking. Some examples are shown to demonstrate the performance and accuracy of the proposed element with special focus on the numerical simulations for the beverage can industry.

A Floating Node Method for the Modelling of Discontinuities Within a Finite Element

NASA Technical Reports Server (NTRS)

Pinho, Silvestre T.; Chen, B. Y.; DeCarvalho, Nelson V.; Baiz, P. M.; Tay, T. E.

2013-01-01

This paper focuses on the accurate numerical representation of complex networks of evolving discontinuities in solids, with particular emphasis on cracks. The limitation of the standard finite element method (FEM) in approximating discontinuous solutions has motivated the development of re-meshing, smeared crack models, the eXtended Finite Element Method (XFEM) and the Phantom Node Method (PNM). We propose a new method which has some similarities to the PNM, but crucially: (i) does not introduce an error on the crack geometry when mapping to natural coordinates; (ii) does not require numerical integration over only part of a domain; (iii) can incorporate weak discontinuities and cohesive cracks more readily; (iv) is ideally suited for the representation of multiple and complex networks of (weak, strong and cohesive) discontinuities; (v) leads to the same solution as a finite element mesh where the discontinuity is represented explicitly; and (vi) is conceptually simpler than the PNM.

Thermal stress analysis of ceramic structures with NASTRAN isoparametric solid elements

NASA Technical Reports Server (NTRS)

Lamberson, S. E.; Paul, D. B.

1978-01-01

The performance of the NASTRAN level 16.0, twenty node, isoparametric bricks (CIHEX2) at thermal loading was studied. A free ceramic plate was modelled using twenty node bricks of varying thicknesses. The thermal loading for this problem was uniform over the surface with an extremely large gradient through the thickness. No mechanical loading was considered. Temperature-dependent mechanical properties were considered in this analysis. The NASTRAN results were compared to one dimensional stress distributions calculated by direct numerical integration.

Nonlinear Finite Element Analysis of Shells with Large Aspect Ratio

NASA Technical Reports Server (NTRS)

Chang, T. Y.; Sawamiphakdi, K.

1984-01-01

A higher order degenerated shell element with nine nodes was selected for large deformation and post-buckling analysis of thick or thin shells. Elastic-plastic material properties are also included. The post-buckling analysis algorithm is given. Using a square plate, it was demonstrated that the none-node element does not have shear locking effect even if its aspect ratio was increased to the order 10 to the 8th power. Two sample problems are given to illustrate the analysis capability of the shell element.

Decohesion Elements using Two and Three-Parameter Mixed-Mode Criteria

NASA Technical Reports Server (NTRS)

Davila, Carlos G.; Camanho, Pedro P.

2001-01-01

An eight-node decohesion element implementing different criteria to predict delamination growth under mixed-mode loading is proposed. The element is used at the interface between solid finite elements to model the initiation and propagation of delamination. A single displacement-based damage parameter is used in a softening law to track the damage state of the interface. The power law criterion and a three-parameter mixed-mode criterion are used to predict delamination growth. The accuracy of the predictions is evaluated in single mode delamination and in the mixed-mode bending tests.

Finite element techniques for the Navier-Stokes equations in the primitive variable formulation and the vorticity stream-function formulation

NASA Technical Reports Server (NTRS)

Glaisner, F.; Tezduyar, T. E.

1987-01-01

Finite element procedures for the Navier-Stokes equations in the primitive variable formulation and the vorticity stream-function formulation have been implemented. For both formulations, streamline-upwind/Petrov-Galerkin techniques are used for the discretization of the transport equations. The main problem associated with the vorticity stream-function formulation is the lack of boundary conditions for vorticity at solid surfaces. Here an implicit treatment of the vorticity at no-slip boundaries is incorporated in a predictor-multicorrector time integration scheme. For the primitive variable formulation, mixed finite-element approximations are used. A nine-node element and a four-node + bubble element have been implemented. The latter is shown to exhibit a checkerboard pressure mode and a numerical treatment for this spurious pressure mode is proposed. The two methods are compared from the points of view of simulating internal and external flows and the possibilities of extensions to three dimensions.

Architecture and method for a burst buffer using flash technology

DOEpatents

Tzelnic, Percy; Faibish, Sorin; Gupta, Uday K.; Bent, John; Grider, Gary Alan; Chen, Hsing-bung

2016-03-15

A parallel supercomputing cluster includes compute nodes interconnected in a mesh of data links for executing an MPI job, and solid-state storage nodes each linked to a respective group of the compute nodes for receiving checkpoint data from the respective compute nodes, and magnetic disk storage linked to each of the solid-state storage nodes for asynchronous migration of the checkpoint data from the solid-state storage nodes to the magnetic disk storage. Each solid-state storage node presents a file system interface to the MPI job, and multiple MPI processes of the MPI job write the checkpoint data to a shared file in the solid-state storage in a strided fashion, and the solid-state storage node asynchronously migrates the checkpoint data from the shared file in the solid-state storage to the magnetic disk storage and writes the checkpoint data to the magnetic disk storage in a sequential fashion.

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

NASA Astrophysics Data System (ADS)

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

2013-02-01

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

Two Dimensional Linear Elastic Analysis of Fracture Specimens User’s Manual of a Finite Element Computer Program.

DTIC Science & Technology

1980-02-01

8 d. Data Set 4 8 e. Data Set 5 9 f. Data Set 6 9 g. Data Set 7 10 h. Data Set 8 10 i. Data Set 9 11 J. Data Set 10 12 k. Data...Coordinates NODE X Y NODE X Y NODE X Y 1 4.0 0.5 7 3.50 1.0 13 1.50 1.5 2 4.0 1.0 8 3.50 1.5 14 1.25 0.5 3 4.0 1.5 9 2.50 0.5 15 1.25 1.5 4 3.75 0.5 10 ...4 1+5 1+6 1+7 1 1 3 8 6 2 5 7 4 2 8 13 11 6 10 12 9 7 3 16 11 13 18 14 12 15 17 Note that I can be chosen to be any corner node. 6. PLOTTING THE

Development of quadrilateral spline thin plate elements using the B-net method

NASA Astrophysics Data System (ADS)

Chen, Juan; Li, Chong-Jun

2013-08-01

The quadrilateral discrete Kirchhoff thin plate bending element DKQ is based on the isoparametric element Q8, however, the accuracy of the isoparametric quadrilateral elements will drop significantly due to mesh distortions. In a previouswork, we constructed an 8-node quadrilateral spline element L8 using the triangular area coordinates and the B-net method, which can be insensitive to mesh distortions and possess the second order completeness in the Cartesian coordinates. In this paper, a thin plate spline element is developed based on the spline element L8 and the refined technique. Numerical examples show that the present element indeed possesses higher accuracy than the DKQ element for distorted meshes.

Finite Element Simulation of Articular Contact Mechanics with Quadratic Tetrahedral Elements

PubMed Central

Maas, Steve A.; Ellis, Benjamin J.; Rawlins, David S.; Weiss, Jeffrey A.

2016-01-01

Although it is easier to generate finite element discretizations with tetrahedral elements, trilinear hexahedral (HEX8) elements are more often used in simulations of articular contact mechanics. This is due to numerical shortcomings of linear tetrahedral (TET4) elements, limited availability of quadratic tetrahedron elements in combination with effective contact algorithms, and the perceived increased computational expense of quadratic finite elements. In this study we implemented both ten-node (TET10) and fifteen-node (TET15) quadratic tetrahedral elements in FEBio (www.febio.org) and compared their accuracy, robustness in terms of convergence behavior and computational cost for simulations relevant to articular contact mechanics. Suitable volume integration and surface integration rules were determined by comparing the results of several benchmark contact problems. The results demonstrated that the surface integration rule used to evaluate the contact integrals for quadratic elements affected both convergence behavior and accuracy of predicted stresses. The computational expense and robustness of both quadratic tetrahedral formulations compared favorably to the HEX8 models. Of note, the TET15 element demonstrated superior convergence behavior and lower computational cost than both the TET10 and HEX8 elements for meshes with similar numbers of degrees of freedom in the contact problems that we examined. Finally, the excellent accuracy and relative efficiency of these quadratic tetrahedral elements was illustrated by comparing their predictions with those for a HEX8 mesh for simulation of articular contact in a fully validated model of the hip. These results demonstrate that TET10 and TET15 elements provide viable alternatives to HEX8 elements for simulation of articular contact mechanics. PMID:26900037

Efficient Broadband Simulation of Fluid-Structure Coupling for Membrane-Type Acoustic Transducer Arrays Using the Multilevel Fast Multipole Algorithm.

PubMed

Shieh, Bernard; Sabra, Karim G; Degertekin, F Levent

2016-11-01

A boundary element model provides great flexibility for the simulation of membrane-type micromachined ultrasonic transducers (MUTs) in terms of membrane shape, actuating mechanism, and array layout. Acoustic crosstalk is accounted for through a mutual impedance matrix that captures the primary crosstalk mechanism of dispersive-guided modes generated at the fluid-solid interface. However, finding the solution to the fully populated boundary element matrix equation using standard techniques requires computation time and memory usage that scales by the cube and by the square of the number of nodes, respectively, limiting simulation to a small number of membranes. We implement a solver with improved speed and efficiency through the application of a multilevel fast multipole algorithm (FMA). By approximating the fields of collections of nodes using multipole expansions of the free-space Green's function, an FMA solver can enable the simulation of hundreds of thousands of nodes while incurring an approximation error that is controllable. Convergence is drastically improved using a problem-specific block-diagonal preconditioner. We demonstrate the solver's capabilities by simulating a 32-element 7-MHz 1-D capacitive MUT (CMUT) phased array with 2880 membranes. The array is simulated using 233280 nodes for a very wide frequency band up to 50 MHz. For a simulation with 15210 nodes, the FMA solver performed ten times faster and used 32 times less memory than a standard solver based on LU decomposition. We investigate the effects of mesh density and phasing on the predicted array response and find that it is necessary to use about seven nodes over the width of the membrane to observe convergence of the solution-even below the first membrane resonance frequency-due to the influence of higher order membrane modes.

A triangular prism solid and shell interactive mapping element for electromagnetic sheet metal forming process

NASA Astrophysics Data System (ADS)

Cui, Xiangyang; Li, She; Feng, Hui; Li, Guangyao

2017-05-01

In this paper, a novel triangular prism solid and shell interactive mapping element is proposed to solve the coupled magnetic-mechanical formulation in electromagnetic sheet metal forming process. A linear six-node "Triprism" element is firstly proposed for transient eddy current analysis in electromagnetic field. In present "Triprism" element, shape functions are given explicitly, and a cell-wise gradient smoothing operation is used to obtain the gradient matrices without evaluating derivatives of shape functions. In mechanical field analysis, a shear locking free triangular shell element is employed in internal force computation, and a data mapping method is developed to transfer the Lorentz force on solid into the external forces suffered by shell structure for dynamic elasto-plasticity deformation analysis. Based on the deformed triangular shell structure, a "Triprism" element generation rule is established for updated electromagnetic analysis, which means inter-transformation of meshes between the coupled fields can be performed automatically. In addition, the dynamic moving mesh is adopted for air mesh updating based on the deformation of sheet metal. A benchmark problem is carried out for confirming the accuracy of the proposed "Triprism" element in predicting flux density in electromagnetic field. Solutions of several EMF problems obtained by present work are compared with experiment results and those of traditional method, which are showing excellent performances of present interactive mapping element.

Finite element simulation of articular contact mechanics with quadratic tetrahedral elements.

PubMed

Maas, Steve A; Ellis, Benjamin J; Rawlins, David S; Weiss, Jeffrey A

2016-03-21

Although it is easier to generate finite element discretizations with tetrahedral elements, trilinear hexahedral (HEX8) elements are more often used in simulations of articular contact mechanics. This is due to numerical shortcomings of linear tetrahedral (TET4) elements, limited availability of quadratic tetrahedron elements in combination with effective contact algorithms, and the perceived increased computational expense of quadratic finite elements. In this study we implemented both ten-node (TET10) and fifteen-node (TET15) quadratic tetrahedral elements in FEBio (www.febio.org) and compared their accuracy, robustness in terms of convergence behavior and computational cost for simulations relevant to articular contact mechanics. Suitable volume integration and surface integration rules were determined by comparing the results of several benchmark contact problems. The results demonstrated that the surface integration rule used to evaluate the contact integrals for quadratic elements affected both convergence behavior and accuracy of predicted stresses. The computational expense and robustness of both quadratic tetrahedral formulations compared favorably to the HEX8 models. Of note, the TET15 element demonstrated superior convergence behavior and lower computational cost than both the TET10 and HEX8 elements for meshes with similar numbers of degrees of freedom in the contact problems that we examined. Finally, the excellent accuracy and relative efficiency of these quadratic tetrahedral elements was illustrated by comparing their predictions with those for a HEX8 mesh for simulation of articular contact in a fully validated model of the hip. These results demonstrate that TET10 and TET15 elements provide viable alternatives to HEX8 elements for simulation of articular contact mechanics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of Finite Element Software on Energy Release Rates Computed Using the Virtual Crack Closure Technique

NASA Technical Reports Server (NTRS)

Krueger, Ronald; Goetze, Dirk; Ransom, Jonathon (Technical Monitor)

2006-01-01

Strain energy release rates were computed along straight delamination fronts of Double Cantilever Beam, End-Notched Flexure and Single Leg Bending specimens using the Virtual Crack Closure Technique (VCCT). Th e results were based on finite element analyses using ABAQUS# and ANSYS# and were calculated from the finite element results using the same post-processing routine to assure a consistent procedure. Mixed-mode strain energy release rates obtained from post-processing finite elem ent results were in good agreement for all element types used and all specimens modeled. Compared to previous studies, the models made of s olid twenty-node hexahedral elements and solid eight-node incompatible mode elements yielded excellent results. For both codes, models made of standard brick elements and elements with reduced integration did not correctly capture the distribution of the energy release rate acr oss the width of the specimens for the models chosen. The results suggested that element types with similar formulation yield matching results independent of the finite element software used. For comparison, m ixed-mode strain energy release rates were also calculated within ABAQUS#/Standard using the VCCT for ABAQUS# add on. For all specimens mod eled, mixed-mode strain energy release rates obtained from ABAQUS# finite element results using post-processing were almost identical to re sults calculated using the VCCT for ABAQUS# add on.

Stress Recovery and Error Estimation for 3-D Shell Structures

NASA Technical Reports Server (NTRS)

Riggs, H. R.

2000-01-01

The C1-continuous stress fields obtained from finite element analyses are in general lower- order accurate than are the corresponding displacement fields. Much effort has focussed on increasing their accuracy and/or their continuity, both for improved stress prediction and especially error estimation. A previous project developed a penalized, discrete least squares variational procedure that increases the accuracy and continuity of the stress field. The variational problem is solved by a post-processing, 'finite-element-type' analysis to recover a smooth, more accurate, C1-continuous stress field given the 'raw' finite element stresses. This analysis has been named the SEA/PDLS. The recovered stress field can be used in a posteriori error estimators, such as the Zienkiewicz-Zhu error estimator or equilibrium error estimators. The procedure was well-developed for the two-dimensional (plane) case involving low-order finite elements. It has been demonstrated that, if optimal finite element stresses are used for the post-processing, the recovered stress field is globally superconvergent. Extension of this work to three dimensional solids is straightforward. Attachment: Stress recovery and error estimation for shell structure (abstract only). A 4-node, shear-deformable flat shell element developed via explicit Kirchhoff constraints (abstract only). A novel four-node quadrilateral smoothing element for stress enhancement and error estimation (abstract only).

Nanophotonic rare-earth quantum memory with optically controlled retrieval

NASA Astrophysics Data System (ADS)

Zhong, Tian; Kindem, Jonathan M.; Bartholomew, John G.; Rochman, Jake; Craiciu, Ioana; Miyazono, Evan; Bettinelli, Marco; Cavalli, Enrico; Verma, Varun; Nam, Sae Woo; Marsili, Francesco; Shaw, Matthew D.; Beyer, Andrew D.; Faraon, Andrei

2017-09-01

Optical quantum memories are essential elements in quantum networks for long-distance distribution of quantum entanglement. Scalable development of quantum network nodes requires on-chip qubit storage functionality with control of the readout time. We demonstrate a high-fidelity nanophotonic quantum memory based on a mesoscopic neodymium ensemble coupled to a photonic crystal cavity. The nanocavity enables >95% spin polarization for efficient initialization of the atomic frequency comb memory and time bin-selective readout through an enhanced optical Stark shift of the comb frequencies. Our solid-state memory is integrable with other chip-scale photon source and detector devices for multiplexed quantum and classical information processing at the network nodes.

A mixed-penalty biphasic finite element formulation incorporating viscous fluids and material interfaces.

PubMed

Chan, B; Donzelli, P S; Spilker, R L

2000-06-01

The fluid viscosity term of the fluid phase constitutive equation and the interface boundary conditions between biphasic, solid and fluid domains have been incorporated into a mixed-penalty finite element formulation of the linear biphasic theory for hydrated soft tissue. The finite element code can now model a single-phase viscous incompressible fluid, or a single-phase elastic solid, as limiting cases of a biphasic material. Interface boundary conditions allow the solution of problems involving combinations of biphasic, fluid and solid regions. To incorporate these conditions, the volume-weighted mixture velocity is introduced as a degree of freedom at interface nodes so that the kinematic continuity conditions are satisfied by conventional finite element assembly techniques. Results comparing our numerical method with an independent, analytic solution for the problem of Couette flow over rigid and deformable porous biphasic layers show that the finite element code accurately predicts the viscous fluid flows and deformation in the porous biphasic region. Thus, the analysis can be used to model the interface between synovial fluid and articular cartilage in diarthrodial joints. This is an important step toward modeling and understanding the mechanisms of joint lubrication and another step toward fully modeling the in vivo behavior of a diarthrodial joint.

Use of Generalized Fluid System Simulation Program (GFSSP) for Teaching and Performing Senior Design Projects at the Educational Institutions

NASA Technical Reports Server (NTRS)

Majumdar, A. K.; Hedayat, A.

2015-01-01

This paper describes the experience of the authors in using the Generalized Fluid System Simulation Program (GFSSP) in teaching Design of Thermal Systems class at University of Alabama in Huntsville. GFSSP is a finite volume based thermo-fluid system network analysis code, developed at NASA/Marshall Space Flight Center, and is extensively used in NASA, Department of Defense, and aerospace industries for propulsion system design, analysis, and performance evaluation. The educational version of GFSSP is freely available to all US higher education institutions. The main purpose of the paper is to illustrate the utilization of this user-friendly code for the thermal systems design and fluid engineering courses and to encourage the instructors to utilize the code for the class assignments as well as senior design projects. The need for a generalized computer program for thermofluid analysis in a flow network has been felt for a long time in aerospace industries. Designers of thermofluid systems often need to know pressures, temperatures, flow rates, concentrations, and heat transfer rates at different parts of a flow circuit for steady state or transient conditions. Such applications occur in propulsion systems for tank pressurization, internal flow analysis of rocket engine turbopumps, chilldown of cryogenic tanks and transfer lines, and many other applications of gas-liquid systems involving fluid transients and conjugate heat and mass transfer. Computer resource requirements to perform time-dependent, three-dimensional Navier-Stokes computational fluid dynamic (CFD) analysis of such systems are prohibitive and therefore are not practical. Available commercial codes are generally suitable for steady state, single-phase incompressible flow. Because of the proprietary nature of such codes, it is not possible to extend their capability to satisfy the above-mentioned needs. Therefore, the Generalized Fluid System Simulation Program (GFSSP1) has been developed at NASA Marshall Space Flight Center (MSFC) as a general fluid flow system solver capable of handling phase changes, compressibility, mixture thermodynamics and transient operations. It also includes the capability to model external body forces such as gravity and centrifugal effects in a complex flow network. The objectives of GFSSP development are: a) to develop a robust and efficient numerical algorithm to solve a system of equations describing a flow network containing phase changes, mixing, and rotation; and b) to implement the algorithm in a structured, easy-to-use computer program. The analysis of thermofluid dynamics in a complex network requires resolution of the system into fluid nodes and branches, and solid nodes and conductors as shown in Figure 1. Figure 1 shows a schematic and GFSSP flow circuit of a counter-flow heat exchanger. Hot nitrogen gas is flowing through a pipe, colder nitrogen is flowing counter to the hot stream in the annulus pipe and heat transfer occurs through metal tubes. The problem considered is to calculate flowrates and temperature distributions in both streams. GFSSP has a unique data structure, as shown in Figure 2, that allows constructing all possible arrangements of a flow network with no limit on the number of elements. The elements of a flow network are boundary nodes where pressure and temperature are specified, internal nodes where pressure and temperature are calculated, and branches where flowrates are calculated. For conjugate heat transfer problems, there are three additional elements: solid node, ambient node, and conductor. The solid and fluid nodes are connected with solid-fluid conductors. GFSSP solves the conservation equations of mass and energy, and equation of state in internal nodes to calculate pressure, temperature and resident mass. The momentum conservation equation is solved in branches to calculate flowrate. It also solves for energy conservation equations to calculate temperatures of solid nodes. The equations are coupled and nonlinear; therefore, they are solved by an iterative numerical scheme. GFSSP employs a unique numerical scheme known as simultaneous adjustment with successive substitution (SASS), which is a combination of Newton-Raphson and successive substitution methods. The mass and momentum conservation equations and the equation of state are solved by the Newton-Raphson method while the conservation of energy and species are solved by the successive substitution method. GFSSP is linked with two thermodynamic property programs, GASP2 and WASP3 and GASPAK4, that provide thermodynamic and thermophysical properties of selected fluids. Both programs cover a range of pressure and temperature that allows fluid properties to be evaluated for liquid, liquid-vapor (saturation), and vapor region. GASP and WASP provide properties of 12 fluids. GASPAK includes a library of 36 fluids. GFSSP has three major parts. The first part is the graphical user interface (GUI), visual thermofluid analyzer of systems and components (VTASC). VTASC allows users to create a flow circuit by a 'point and click' paradigm. It creates the GFSSP input file after the completion of the model building process. GFSSP's GUI provides the users a platform to build and run their models. It also allows post-processing of results. The network flow circuit is first built using three basic elements: boundary node, internal node, and branch.

Study of hypervelocity meteoroid impact on orbital space stations

NASA Technical Reports Server (NTRS)

Leimbach, K. R.; Prozan, R. J.

1973-01-01

Structural damage resulting in hypervelocity impact of a meteorite on a spacecraft is discussed. Of particular interest is the backside spallation caused by such a collision. To treat this phenomenon two numerical schemes were developed in the course of this study to compute the elastic-plastic flow fracture of a solid. The numerical schemes are a five-point finite difference scheme and a four-node finite element scheme. The four-node finite element scheme proved to be less sensitive to the type of boundary conditions and loadings. Although further development work is needed to improve the program versatility (generalization of the network topology, secondary storage for large systems, improving of the coding to reduce the run time, etc.), the basic framework is provided for a utilitarian computer program which may be used in a wide variety of situations. Analytic results showing the program output are given for several test cases.

Method for forming cooperative binary ionic solids

DOEpatents

Shelnutt, John A.; Martin, Kathleen E.; Wang, Zhongchun; Medforth, Craig J.

2013-03-05

A nanostructured molecular unit and method for forming is described where a cationic porphyrin having an ethanolic substituent species and a metal in the porphyrin cavity is combined with an anionic porphyrin having a sulfonate substituent species and a metal in the porphyrin cavity to form by self-assembly a nanostructured molecular unit with a morphology comprising four dendritic elements connected at a central node.

Method for forming cooperative binary ionic solids

DOEpatents

Shelnutt, John A.; Martin, Kathleen E.; Wang, Zhongchun; Medforth, Craig J.

2014-09-09

A nanostructured molecular unit and method for forming is described where a cationic porphyrin having an ethanolic substituent species and a metal in the porphyrin cavity is combined with an anionic porphyrin having a sulfonate substituent species and a metal in the porphyrin cavity to form by self-assembly a nanostructured molecular unit with a morphology comprising four dendritic elements connected at a central node.

Castleman's disease of the spleen.

PubMed

Mantas, Dimitrios; Damaskos, Christos; Dailiani, Panagiota; Samarkos, Michael; Korkolopoulou, Penelope

2017-06-01

Castleman's disease (CD), also known as giant or angiofolicular lymphoid hyperplasia or lymphoid hamartoma, is a group of atypical lymphoproliferative disorders that share common lymph node histological features and may be localized either to a single lymph node (unicentric) or occur systemically (multicentric). Herein, we present a rare case of a of 75-year-old female patient who was referred to our department and after a thorough work-up, underwent splenectomy with synchronous resection of an accessory spleen, splenic artery lymph nodes, and splenic hilar lymph nodes due to splenic involvement in a multicentric CD. The pathology of the specimens led to the conclusion that it was a case of polycentric HHV-8-positive CD, affecting the spleen, the accessory spleen, and the lymph nodes. Incidence of this rare condition is believed to be approximately 0.001-0.05%. CD has been linked to the human immunodeficiency virus (HIV), human herpes virus 8 (HHV-8), and is associated with malignancies. The pathogenesis mechanism is considered to be a dysregulation and hypersecretion of cytokines, either idiopathic or secondary to a viral infection, with the latter considered the most frequent. Solid organ involvement is very rare as is splenic involvement.

Solid Lymph Nodes as an Imaging Biomarker for Risk Stratification in Human Papillomavirus-Related Oropharyngeal Squamous Cell Carcinoma.

PubMed

Rath, T J; Narayanan, S; Hughes, M A; Ferris, R L; Chiosea, S I; Branstetter, B F

2017-07-01

Human papillomavirus-related oropharyngeal squamous cell carcinoma is associated with cystic lymph nodes on CT and has a favorable prognosis. A subset of patients with aggressive disease experience treatment failure. Our aim was to determine whether the extent of cystic lymph node burden on staging CT can serve as an imaging biomarker to predict treatment failure in human papillomavirus-related oropharyngeal squamous cell carcinoma. We identified patients with human papilloma virus-related oropharyngeal squamous cell carcinoma and staging neck CTs. Demographic and clinical variables were recorded. We retrospectively classified the metastatic lymph node burden on CT as cystic or solid and assessed radiologic extracapsular spread. Biopsy, subsequent imaging, or clinical follow-up was the reference standard for treatment failure. The primary end point was disease-free survival. Cox proportional hazard regression analyses of clinical, demographic, and anatomic variables for treatment failure were performed. One hundred eighty-three patients were included with a mean follow-up of 38 months. In univariate analysis, the following variables had a statistically significant association with treatment failure: solid-versus-cystic lymph nodes, clinical T-stage, clinical N-stage, and radiologic evidence of extracapsular spread. The multivariate Cox proportional hazard model resulted in a model that included solid-versus-cystic lymph nodes, T-stage, and radiologic evidence of extracapsular spread as independent predictors of treatment failure. Patients with cystic nodal metastasis at staging had significantly better disease-free survival than patients with solid lymph nodes. In human papilloma virus-related oropharyngeal squamous cell carcinoma, patients with solid lymph node metastases are at higher risk for treatment failure with worse disease-free survival. Solid lymph nodes may serve as an imaging biomarker to tailor individual treatment regimens. © 2017 by American Journal of Neuroradiology.

A comparative study on different methods of automatic mesh generation of human femurs.

PubMed

Viceconti, M; Bellingeri, L; Cristofolini, L; Toni, A

1998-01-01

The aim of this study was to evaluate comparatively five methods for automating mesh generation (AMG) when used to mesh a human femur. The five AMG methods considered were: mapped mesh, which provides hexahedral elements through a direct mapping of the element onto the geometry; tetra mesh, which generates tetrahedral elements from a solid model of the object geometry; voxel mesh which builds cubic 8-node elements directly from CT images; and hexa mesh that automatically generated hexahedral elements from a surface definition of the femur geometry. The various methods were tested against two reference models: a simplified geometric model and a proximal femur model. The first model was useful to assess the inherent accuracy of the meshes created by the AMG methods, since an analytical solution was available for the elastic problem of the simplified geometric model. The femur model was used to test the AMG methods in a more realistic condition. The femoral geometry was derived from a reference model (the "standardized femur") and the finite element analyses predictions were compared to experimental measurements. All methods were evaluated in terms of human and computer effort needed to carry out the complete analysis, and in terms of accuracy. The comparison demonstrated that each tested method deserves attention and may be the best for specific situations. The mapped AMG method requires a significant human effort but is very accurate and it allows a tight control of the mesh structure. The tetra AMG method requires a solid model of the object to be analysed but is widely available and accurate. The hexa AMG method requires a significant computer effort but can also be used on polygonal models and is very accurate. The voxel AMG method requires a huge number of elements to reach an accuracy comparable to that of the other methods, but it does not require any pre-processing of the CT dataset to extract the geometry and in some cases may be the only viable solution.

FLUSH - PREDICTION OF FLOW PARAMETERS OF SLUSH HYDROGEN

NASA Technical Reports Server (NTRS)

Hardy, T.

1994-01-01

Slush hydrogen, a mixture of the solid and liquid phases of hydrogen, is a possible source of fuel for the National Aerospace Plane (NASP) Project. Advantages of slush hydrogen over liquid hydrogen include greater heat capacity and greater density. However, practical use of slush hydrogen as a fuel requires systems of lines, valves, etc. which are designed to deliver the fuel in slush form with minimal solid loss as a result of pipe heating or flow friction. Engineers involved with the NASP Project developed FLUSH to calculate the pressure drop and slush hydrogen solid fraction loss for steady-state, one-dimensional flow. FLUSH solves the steady-state, one-dimensional energy equation and the Bernoulli equation for pipe flow. The program performs these calculations for each two-node element--straight pipe length, elbow, valve, fitting, or other part of the piping system--specified by the user. The user provides flow rate, upstream pressure, initial solid hydrogen fraction, element heat leak, and element parameters such as length and diameter. For each element, FLUSH first calculates the pressure drop, then figures the slush solid fraction exiting the element. The code employs GASPLUS routines to calculate thermodynamic properties for the slush hydrogen. FLUSH is written in FORTRAN IV for DEC VAX series computers running VMS. An executable is provided on the tape. The GASPLUS physical properties routines which are required for building the executable are included as one object library on the program media (full source code for GASPLUS is available separately as COSMIC Program Number LEW-15091). FLUSH is available in DEC VAX BACKUP format on a 9-track 1600 BPI magnetic tape (standard media) or on a TK50 tape cartridge. FLUSH was developed in 1989.

Growth and Deposition of Inorganic Nutrient Elements in Developing Leaves of Zea mays L. 1

PubMed Central

Meiri, Avraham; Silk, Wendy Kuhn; Läuchli, André

1992-01-01

Spatial distributions of growth and of the concentration of some inorganic nutrient elements were analyzed in developing leaves of maize (Zea mays L.). Growth was analyzed by pinprick experiments with numerical analysis to characterize fields of velocity and relative elemental elongation rate. Inductively coupled plasma and atomic emission spectroscopy were used to measure nutrients extracted from segments of leaf tissue collected by position. Leaves 7 and 8, both elongating 3 millimeters per hour had maximum relative elemental growth rates of 0.06 to 0.08 millimeters per hour with maximum rates 20 to 50 millimeters from the node and cessation of growth by 90 millimeters from the node. Spatial distribution of dry weight density revealed that the rate of biomass deposition was maximum in the most rapidly expanding region and continued beyond the elongation zone. The nutrient elements K, Cl, Ca, Mg, and P showed different distribution patterns of ion density (on a dry weight basis). K and Cl had minimal density in the leaf tips; K density was maximum in the growing region, whereas Cl density was maximum at the region of growth cessation. Ca, Mg, and P had relatively high densities at the base of the elongation zone near the node and also in the tip regions. Near the node, P and Mg densities were higher in the young, growing leaves, whereas Ca density near the node was higher in older leaves that had completed elongation. Deposition rates of all nutrients were greatest in the region of maximum elongation rate. PMID:16669027

Database Design for Structural Analysis and Design Optimization.

DTIC Science & Technology

1984-10-01

2) . Element number of nodes IELT NPAR(2) " Stress printing flag IPST NPAR(2) Element material angle BETA NPAR(2) Element thickness THICK NPAR(2...number LM 3*NPAR(17)*NPAR(2) Element nodal coordinates XYZ 3*NPAR(17)*NPAR(2) Element number of nodes IELT NPAR(2) Element geometry number of nodes IELTX...D.O.F. number LM 6*NPAR(7)*NPAR(2) Element number of nodes IELT NPAR(2) Material property set number MATP NPAR(2) Material constants PROP NPAR(17

Stress and deformation analysis of tapered cantilever castellated beam using numerical method

NASA Astrophysics Data System (ADS)

Ilham Maulana, Taufiq; Soebandono, Bagus; Satria Jagad, Beta; Prayuda, Hakas

2018-05-01

The castellated beam is often used in buildings because of its lighter weight compared with a normal steel beam. There are many types of an opening in the castellated beam, one of which is hexagonal openings. This paper will discuss the analysis of stress and deformation on castellated beam with a variation of openings diameter, space between holes, and angle of hexagonal openings. Furthermore, stress distribution on specimen will be seen under static loading. This study used IWF section 150x75x5x7 with 4 variations of the span with one fixed support, and yield strength is 400 MPa. Linear finite element analysis is used with 10-node tetrahedron solid element, by observing von Misses stress. The software used in this study are freeware, which is LISAFEA 8.0 for analyzing and FreeCAD for drawing. The result shows that value of stress and deformation for each sample is quite volatile, but it can be concluded that stress distribution around the opening is larger than in web and flange.

Multiresolution molecular mechanics: Surface effects in nanoscale materials

NASA Astrophysics Data System (ADS)

Yang, Qingcheng; To, Albert C.

2017-05-01

Surface effects have been observed to contribute significantly to the mechanical response of nanoscale structures. The newly proposed energy-based coarse-grained atomistic method Multiresolution Molecular Mechanics (MMM) (Yang, To (2015), [57]) is applied to capture surface effect for nanosized structures by designing a surface summation rule SRS within the framework of MMM. Combined with previously proposed bulk summation rule SRB, the MMM summation rule SRMMM is completed. SRS and SRB are consistently formed within SRMMM for general finite element shape functions. Analogous to quadrature rules in finite element method (FEM), the key idea to the good performance of SRMMM lies in that the order or distribution of energy for coarse-grained atomistic model is mathematically derived such that the number, position and weight of quadrature-type (sampling) atoms can be determined. Mathematically, the derived energy distribution of surface area is different from that of bulk region. Physically, the difference is due to the fact that surface atoms lack neighboring bonding. As such, SRS and SRB are employed for surface and bulk domains, respectively. Two- and three-dimensional numerical examples using the respective 4-node bilinear quadrilateral, 8-node quadratic quadrilateral and 8-node hexahedral meshes are employed to verify and validate the proposed approach. It is shown that MMM with SRMMM accurately captures corner, edge and surface effects with less 0.3% degrees of freedom of the original atomistic system, compared against full atomistic simulation. The effectiveness of SRMMM with respect to high order element is also demonstrated by employing the 8-node quadratic quadrilateral to solve a beam bending problem considering surface effect. In addition, the introduced sampling error with SRMMM that is analogous to numerical integration error with quadrature rule in FEM is very small.

Method and apparatus for offloading compute resources to a flash co-processing appliance

DOEpatents

Tzelnic, Percy; Faibish, Sorin; Gupta, Uday K.; Bent, John; Grider, Gary Alan; Chen, Hsing -bung

2015-10-13

Solid-State Drive (SSD) burst buffer nodes are interposed into a parallel supercomputing cluster to enable fast burst checkpoint of cluster memory to or from nearby interconnected solid-state storage with asynchronous migration between the burst buffer nodes and slower more distant disk storage. The SSD nodes also perform tasks offloaded from the compute nodes or associated with the checkpoint data. For example, the data for the next job is preloaded in the SSD node and very fast uploaded to the respective compute node just before the next job starts. During a job, the SSD nodes perform fast visualization and statistical analysis upon the checkpoint data. The SSD nodes can also perform data reduction and encryption of the checkpoint data.

Calibration of a dissolved-solids model for the Yampa River basin between Steamboat Springs and Maybell, northwestern Colorado

USGS Publications Warehouse

Parker, R.S.; Litke, D.W.

1987-01-01

The cumulative effects of changes in dissolved solids from a number of coal mines are needed to evaluate effects on downstream water use. A model for determining cumulative effects of streamflow, dissolved-solids concentration, and dissolved-solids load was calibrated for the Yampa River and its tributaries in northwestern Colorado. The model uses accounting principles. It establishes nodes on the stream system and sums water quantity and quality from node to node in the downstream direction. The model operates on a monthly time step for the study period that includes water years 1976 through 1981. Output is monthly mean streamflow, dissolved-solids concentration, and dissolved-solids load. Streamflow and dissolved-solids data from streamflow-gaging stations and other data-collection sites were used to define input data sets to initiate and to calibrate the model. The model was calibrated at four nodes and generally was within 10 percent of the observed values. The calibrated model can compute changes in dissolved-solids concentration or load resulting from the cumulative effects of new coal mines or the expansion of old coal mines in the Yampa River basin. (USGS)

Three-Dimensional Dynamic Analyses of Track-Embankment-Ground System Subjected to High Speed Train Loads

PubMed Central

2014-01-01

A three-dimensional finite element model was developed to investigate dynamic response of track-embankment-ground system subjected to moving loads caused by high speed trains. The track-embankment-ground systems such as the sleepers, the ballast, the embankment, and the ground are represented by 8-noded solid elements. The infinite elements are used to represent the infinite boundary condition to absorb vibration waves induced by the passing of train load at the boundary. The loads were applied on the rails directly to simulate the real moving loads of trains. The effects of train speed on dynamic response of the system are considered. The effect of material parameters, especially the modulus changes of ballast and embankment, is taken into account to demonstrate the effectiveness of strengthening the ballast, embankment, and ground for mitigating system vibration in detail. The numerical results show that the model is reliable for predicting the amplitude of vibrations produced in the track-embankment-ground system by high-speed trains. Stiffening of fill under the embankment can reduce the vibration level, on the other hand, it can be realized by installing a concrete slab under the embankment. The influence of axle load on the vibration of the system is obviously lower than that of train speed. PMID:24723838

Three-dimensional dynamic analyses of track-embankment-ground system subjected to high speed train loads.

PubMed

Fu, Qiang; Zheng, Changjie

2014-01-01

A three-dimensional finite element model was developed to investigate dynamic response of track-embankment-ground system subjected to moving loads caused by high speed trains. The track-embankment-ground systems such as the sleepers, the ballast, the embankment, and the ground are represented by 8-noded solid elements. The infinite elements are used to represent the infinite boundary condition to absorb vibration waves induced by the passing of train load at the boundary. The loads were applied on the rails directly to simulate the real moving loads of trains. The effects of train speed on dynamic response of the system are considered. The effect of material parameters, especially the modulus changes of ballast and embankment, is taken into account to demonstrate the effectiveness of strengthening the ballast, embankment, and ground for mitigating system vibration in detail. The numerical results show that the model is reliable for predicting the amplitude of vibrations produced in the track-embankment-ground system by high-speed trains. Stiffening of fill under the embankment can reduce the vibration level, on the other hand, it can be realized by installing a concrete slab under the embankment. The influence of axle load on the vibration of the system is obviously lower than that of train speed.

Comparisons of node-based and element-based approaches of assigning bone material properties onto subject-specific finite element models.

PubMed

Chen, G; Wu, F Y; Liu, Z C; Yang, K; Cui, F

2015-08-01

Subject-specific finite element (FE) models can be generated from computed tomography (CT) datasets of a bone. A key step is assigning material properties automatically onto finite element models, which remains a great challenge. This paper proposes a node-based assignment approach and also compares it with the element-based approach in the literature. Both approaches were implemented using ABAQUS. The assignment procedure is divided into two steps: generating the data file of the image intensity of a bone in a MATLAB program and reading the data file into ABAQUS via user subroutines. The node-based approach assigns the material properties to each node of the finite element mesh, while the element-based approach assigns the material properties directly to each integration point of an element. Both approaches are independent from the type of elements. A number of FE meshes are tested and both give accurate solutions; comparatively the node-based approach involves less programming effort. The node-based approach is also independent from the type of analyses; it has been tested on the nonlinear analysis of a Sawbone femur. The node-based approach substantially improves the level of automation of the assignment procedure of bone material properties. It is the simplest and most powerful approach that is applicable to many types of analyses and elements. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Impact of solids on composite materials

NASA Technical Reports Server (NTRS)

Bronson, Arturo; Maldonado, Jerry; Chern, Tzong; Martinez, Francisco; Mccord-Medrano, Johnnie; Roschke, Paul N.

1987-01-01

The failure modes of composite materials as a result of low velocity impact were investigated by simulating the impact with a finite element analysis. An important facet of the project is the modeling of the impact of a solid onto cylindrical shells composed of composite materials. The model under development will simulate the delamination sustained when a composite material encounters impact from another rigid body. The computer equipment was installed, the computer network tested, and a finite element method model was developed to compare results with known experimental data. The model simulated the impact of a steel rod onto a rotating shaft. Pre-processing programs (GMESH and TANVEL) were developed to generate node and element data for the input into the three dimensional, dynamic finite element analysis code (DYNA3D). The finite element mesh was configured with a fine mesh near the impact zone and a coarser mesh for the impacting rod and the regions surrounding the impacting zone. For the computer simulation, five impacting loads were used to determine the time history of the stresses, the scribed surface areas, and the amount of ridging. The processing time of the computer codes amounted from 1 to 4 days. The calculated surface area were within 6-12 percent, relative error when compated to the actual scratch area.

Efficient implementation of multidimensional fast fourier transform on a distributed-memory parallel multi-node computer

DOEpatents

Bhanot, Gyan V [Princeton, NJ; Chen, Dong [Croton-On-Hudson, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Steinmacher-Burow, Burkhard D [Mount Kisco, NY; Vranas, Pavlos M [Bedford Hills, NY

2012-01-10

The present in invention is directed to a method, system and program storage device for efficiently implementing a multidimensional Fast Fourier Transform (FFT) of a multidimensional array comprising a plurality of elements initially distributed in a multi-node computer system comprising a plurality of nodes in communication over a network, comprising: distributing the plurality of elements of the array in a first dimension across the plurality of nodes of the computer system over the network to facilitate a first one-dimensional FFT; performing the first one-dimensional FFT on the elements of the array distributed at each node in the first dimension; re-distributing the one-dimensional FFT-transformed elements at each node in a second dimension via "all-to-all" distribution in random order across other nodes of the computer system over the network; and performing a second one-dimensional FFT on elements of the array re-distributed at each node in the second dimension, wherein the random order facilitates efficient utilization of the network thereby efficiently implementing the multidimensional FFT. The "all-to-all" re-distribution of array elements is further efficiently implemented in applications other than the multidimensional FFT on the distributed-memory parallel supercomputer.

Efficient implementation of a multidimensional fast fourier transform on a distributed-memory parallel multi-node computer

DOEpatents

Bhanot, Gyan V [Princeton, NJ; Chen, Dong [Croton-On-Hudson, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Steinmacher-Burow, Burkhard D [Mount Kisco, NY; Vranas, Pavlos M [Bedford Hills, NY

2008-01-01

The present in invention is directed to a method, system and program storage device for efficiently implementing a multidimensional Fast Fourier Transform (FFT) of a multidimensional array comprising a plurality of elements initially distributed in a multi-node computer system comprising a plurality of nodes in communication over a network, comprising: distributing the plurality of elements of the array in a first dimension across the plurality of nodes of the computer system over the network to facilitate a first one-dimensional FFT; performing the first one-dimensional FFT on the elements of the array distributed at each node in the first dimension; re-distributing the one-dimensional FFT-transformed elements at each node in a second dimension via "all-to-all" distribution in random order across other nodes of the computer system over the network; and performing a second one-dimensional FFT on elements of the array re-distributed at each node in the second dimension, wherein the random order facilitates efficient utilization of the network thereby efficiently implementing the multidimensional FFT. The "all-to-all" re-distribution of array elements is further efficiently implemented in applications other than the multidimensional FFT on the distributed-memory parallel supercomputer.

A Novel Four-Node Quadrilateral Smoothing Element for Stress Enhancement and Error Estimation

NASA Technical Reports Server (NTRS)

Tessler, A.; Riggs, H. R.; Dambach, M.

1998-01-01

A four-node, quadrilateral smoothing element is developed based upon a penalized-discrete-least-squares variational formulation. The smoothing methodology recovers C1-continuous stresses, thus enabling effective a posteriori error estimation and automatic adaptive mesh refinement. The element formulation is originated with a five-node macro-element configuration consisting of four triangular anisoparametric smoothing elements in a cross-diagonal pattern. This element pattern enables a convenient closed-form solution for the degrees of freedom of the interior node, resulting from enforcing explicitly a set of natural edge-wise penalty constraints. The degree-of-freedom reduction scheme leads to a very efficient formulation of a four-node quadrilateral smoothing element without any compromise in robustness and accuracy of the smoothing analysis. The application examples include stress recovery and error estimation in adaptive mesh refinement solutions for an elasticity problem and an aerospace structural component.

Finite element methods for the biomechanics of soft hydrated tissues: nonlinear analysis and adaptive control of meshes.

PubMed

Spilker, R L; de Almeida, E S; Donzelli, P S

1992-01-01

This chapter addresses computationally demanding numerical formulations in the biomechanics of soft tissues. The theory of mixtures can be used to represent soft hydrated tissues in the human musculoskeletal system as a two-phase continuum consisting of an incompressible solid phase (collagen and proteoglycan) and an incompressible fluid phase (interstitial water). We first consider the finite deformation of soft hydrated tissues in which the solid phase is represented as hyperelastic. A finite element formulation of the governing nonlinear biphasic equations is presented based on a mixed-penalty approach and derived using the weighted residual method. Fluid and solid phase deformation, velocity, and pressure are interpolated within each element, and the pressure variables within each element are eliminated at the element level. A system of nonlinear, first-order differential equations in the fluid and solid phase deformation and velocity is obtained. In order to solve these equations, the contributions of the hyperelastic solid phase are incrementally linearized, a finite difference rule is introduced for temporal discretization, and an iterative scheme is adopted to achieve equilibrium at the end of each time increment. We demonstrate the accuracy and adequacy of the procedure using a six-node, isoparametric axisymmetric element, and we present an example problem for which independent numerical solution is available. Next, we present an automated, adaptive environment for the simulation of soft tissue continua in which the finite element analysis is coupled with automatic mesh generation, error indicators, and projection methods. Mesh generation and updating, including both refinement and coarsening, for the two-dimensional examples examined in this study are performed using the finite quadtree approach. The adaptive analysis is based on an error indicator which is the L2 norm of the difference between the finite element solution and a projected finite element solution. Total stress, calculated as the sum of the solid and fluid phase stresses, is used in the error indicator. To allow the finite difference algorithm to proceed in time using an updated mesh, solution values must be transferred to the new nodal locations. This rezoning is accomplished using a projected field for the primary variables. The accuracy and effectiveness of this adaptive finite element analysis is demonstrated using a linear, two-dimensional, axisymmetric problem corresponding to the indentation of a thin sheet of soft tissue. The method is shown to effectively capture the steep gradients and to produce solutions in good agreement with independent, converged, numerical solutions.

Improved nine-node shell element MITC9i with reduced distortion sensitivity

NASA Astrophysics Data System (ADS)

Wisniewski, K.; Turska, E.

2017-11-01

The 9-node quadrilateral shell element MITC9i is developed for the Reissner-Mindlin shell kinematics, the extended potential energy and Green strain. The following features of its formulation ensure an improved behavior: 1. The MITC technique is used to avoid locking, and we propose improved transformations for bending and transverse shear strains, which render that all patch tests are passed for the regular mesh, i.e. with straight element sides and middle positions of midside nodes and a central node. 2. To reduce shape distortion effects, the so-called corrected shape functions of Celia and Gray (Int J Numer Meth Eng 20:1447-1459, 1984) are extended to shells and used instead of the standard ones. In effect, all patch tests are passed additionally for shifts of the midside nodes along straight element sides and for arbitrary shifts of the central node. 3. Several extensions of the corrected shape functions are proposed to enable computations of non-flat shells. In particular, a criterion is put forward to determine the shift parameters associated with the central node for non-flat elements. Additionally, the method is presented to construct a parabolic side for a shifted midside node, which improves accuracy for symmetric curved edges. Drilling rotations are included by using the drilling Rotation Constraint equation, in a way consistent with the additive/multiplicative rotation update scheme for large rotations. We show that the corrected shape functions reduce the sensitivity of the solution to the regularization parameter γ of the penalty method for this constraint. The MITC9i shell element is subjected to a range of linear and non-linear tests to show passing the patch tests, the absence of locking, very good accuracy and insensitivity to node shifts. It favorably compares to several other tested 9-node elements.

A computer program for anisotropic shallow-shell finite elements using symbolic integration

NASA Technical Reports Server (NTRS)

Andersen, C. M.; Bowen, J. T.

1976-01-01

A FORTRAN computer program for anisotropic shallow-shell finite elements with variable curvature is described. A listing of the program is presented together with printed output for a sample case. Computation times and central memory requirements are given for several different elements. The program is based on a stiffness (displacement) finite-element model in which the fundamental unknowns consist of both the displacement and the rotation components of the reference surface of the shell. Two triangular and four quadrilateral elements are implemented in the program. The triangular elements have 6 or 10 nodes, and the quadrilateral elements have 4 or 8 nodes. Two of the quadrilateral elements have internal degrees of freedom associated with displacement modes which vanish along the edges of the elements (bubble modes). The triangular elements and the remaining two quadrilateral elements do not have bubble modes. The output from the program consists of arrays corresponding to the stiffness, the geometric stiffness, the consistent mass, and the consistent load matrices for individual elements. The integrals required for the generation of these arrays are evaluated by using symbolic (or analytic) integration in conjunction with certain group-theoretic techniques. The analytic expressions for the integrals are exact and were developed using the symbolic and algebraic manipulation language.

Nanophotonic rare-earth quantum memory with optically controlled retrieval.

PubMed

Zhong, Tian; Kindem, Jonathan M; Bartholomew, John G; Rochman, Jake; Craiciu, Ioana; Miyazono, Evan; Bettinelli, Marco; Cavalli, Enrico; Verma, Varun; Nam, Sae Woo; Marsili, Francesco; Shaw, Matthew D; Beyer, Andrew D; Faraon, Andrei

2017-09-29

Optical quantum memories are essential elements in quantum networks for long-distance distribution of quantum entanglement. Scalable development of quantum network nodes requires on-chip qubit storage functionality with control of the readout time. We demonstrate a high-fidelity nanophotonic quantum memory based on a mesoscopic neodymium ensemble coupled to a photonic crystal cavity. The nanocavity enables >95% spin polarization for efficient initialization of the atomic frequency comb memory and time bin-selective readout through an enhanced optical Stark shift of the comb frequencies. Our solid-state memory is integrable with other chip-scale photon source and detector devices for multiplexed quantum and classical information processing at the network nodes. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Parallel fast multipole boundary element method applied to computational homogenization

NASA Astrophysics Data System (ADS)

Ptaszny, Jacek

2018-01-01

In the present work, a fast multipole boundary element method (FMBEM) and a parallel computer code for 3D elasticity problem is developed and applied to the computational homogenization of a solid containing spherical voids. The system of equation is solved by using the GMRES iterative solver. The boundary of the body is dicretized by using the quadrilateral serendipity elements with an adaptive numerical integration. Operations related to a single GMRES iteration, performed by traversing the corresponding tree structure upwards and downwards, are parallelized by using the OpenMP standard. The assignment of tasks to threads is based on the assumption that the tree nodes at which the moment transformations are initialized can be partitioned into disjoint sets of equal or approximately equal size and assigned to the threads. The achieved speedup as a function of number of threads is examined.

A new axi-symmetric element for thin walled structures

NASA Astrophysics Data System (ADS)

Cardoso, Rui P. R.; Yoon, Jeong Whan; Dick, Robert E.

2010-03-01

A new axi-symmetric finite element for thin walled structures is presented in this work. It uses the solid-shell element’s concept with only a single element and multiple integration points along the thickness direction. The cross-section of the element is composed of four nodes with two degrees of freedom each. The proposed formulation overcomes many locking pathologies including transverse shear locking, Poisson’s locking and volumetric locking. For transverse shear locking, the formulation uses the selective reduced integration technique, for Poisson’s locking it uses the enhanced assumed strain (EAS) method with only one enhancing variable. The B-bar approach is used to eliminate the isochoric deformations in the hourglass field while the EAS method is used to alleviate the volumetric locking in the constant part of the deformation tensor. Several examples are shown to demonstrate the performance and accuracy of the proposed element with special focus on the numerical simulations for the beverage can industry.

A refined finite element method for bending analysis of laminated plates integrated with piezoelectric fiber-reinforced composite actuators

NASA Astrophysics Data System (ADS)

Rouzegar, J.; Abbasi, A.

2018-03-01

This research presents a finite element formulation based on four-variable refined plate theory for bending analysis of cross-ply and angle-ply laminated composite plates integrated with a piezoelectric fiber-reinforced composite actuator under electromechanical loading. The four-variable refined plate theory is a simple and efficient higher-order shear deformation theory, which predicts parabolic variation of transverse shear stresses across the plate thickness and satisfies zero traction conditions on the plate free surfaces. The weak form of governing equations is derived using the principle of minimum potential energy, and a 4-node non-conforming rectangular plate element with 8 degrees of freedom per node is introduced for discretizing the domain. Several benchmark problems are solved by the developed MATLAB code and the obtained results are compared with those from exact and other numerical solutions, showing good agreement.

Performance of an anisotropic Allman/DKT 3-node thin triangular flat shell element

NASA Astrophysics Data System (ADS)

Ertas, A.; Krafcik, J. T.; Ekwaro-Osire, S.

1992-05-01

A simple, explicit formulation of the stiffness matrix for an anisotropic, 3-node, thin triangular flat shell element in global coordinates is presented. An Allman triangle (AT) is used for membrane stiffness. The membrane stiffness matrix is explicitly derived by applying an Allman transformation to a Felippa 6-node linear strain triangle (LST). Bending stiffness is incorporated by the use of a discrete Kirchhoff triangle (DKT) bending element. Stiffness terms resulting from anisotropic membrane-bending coupling are included by integrating, in area coordinates, the membrane and bending strain-displacement matrices. Using the aforementioned approach, the objective of this study is to develop and test the performance of a practical 3-node flat shell element that could be used in plate problems with unsymmetrically stacked composite laminates. The performance of the latter element is tested on plates of varying aspect ratios. The developed 3-node shell element should simplify the programming task and have the potential of reducing the computational time.

Rate of regional nodal metastases of cutaneous squamous cell carcinoma in the immunosuppressed patient.

PubMed

McLaughlin, Eamon J; Miller, Lauren; Shin, Thuzar M; Sobanko, Joseph F; Cannady, Steven B; Miller, Christopher J; Newman, Jason G

Immunosuppressed solid organ transplant recipients (SOTRs) have an increased risk of developing cutaneous squamous cell carcinomas (cSCCs) with metastatic potential. This study sought to determine the rate of regional lymph node involvement in a large cohort of solid organ transplant patients with cutaneous head and neck squamous cell carcinoma. A retrospective chart review was performed on solid organ transplant patients with head and neck cutaneous squamous cell carcinoma treated at a tertiary academic medical center from 2005 to 2015. 130 solid organ transplant patients underwent resection of 383 head and neck cutaneous squamous cell carcinomas. The average age of the patient was 63. Seven patients (5%) developed regional lymph node metastases (3 parotid, 4 cervical lymph nodes). The mean time from primary tumor resection to diagnosis of regional lymphatic disease was 6.7months. Six of these patients underwent definitive surgical resection followed by adjuvant radiation; one patient underwent definitive chemoradiation. 6 of the 7 patients died of disease progression with a mean survival of 15months. The average follow up time was 3years (minimum 6months). Solid organ transplant recipients with cutaneous squamous cell carcinoma of the head and neck develop regional lymph node metastasis at a rate of 5%. Regional lymph node metastasis in this population has a poor prognosis and requires aggressive management and surveillance. Copyright © 2017 Elsevier Inc. All rights reserved.

Numerical Modeling of Conjugate Heat Transfer in Fluid Network

NASA Technical Reports Server (NTRS)

Majumdar, Alok

2004-01-01

Fluid network modeling with conjugate heat transfer has many applications in Aerospace engineering. In modeling unsteady flow with heat transfer, it is important to know the variation of wall temperature in time and space to calculate heat transfer between solid to fluid. Since wall temperature is a function of flow, a coupled analysis of temperature of solid and fluid is necessary. In cryogenic applications, modeling of conjugate heat transfer is of great importance to correctly predict boil-off rate in propellant tanks and chill down of transfer lines. In TFAWS 2003, the present author delivered a paper to describe a general-purpose computer program, GFSSP (Generalized Fluid System Simulation Program). GFSSP calculates flow distribution in complex flow circuit for compressible/incompressible, with or without heat transfer or phase change in all real fluids or mixtures. The flow circuit constitutes of fluid nodes and branches. The mass, energy and specie conservation equations are solved at the nodes where as momentum conservation equations are solved at the branches. The proposed paper describes the extension of GFSSP to model conjugate heat transfer. The network also includes solid nodes and conductors in addition to fluid nodes and branches. The energy conservation equations for solid nodes solves to determine the temperatures of the solid nodes simultaneously with all conservation equations governing fluid flow. The numerical scheme accounts for conduction, convection and radiation heat transfer. The paper will also describe the applications of the code to predict chill down of cryogenic transfer line and boil-off rate of cryogenic propellant storage tank.

Moving Particles Through a Finite Element Mesh

PubMed Central

Peskin, Adele P.; Hardin, Gary R.

1998-01-01

We present a new numerical technique for modeling the flow around multiple objects moving in a fluid. The method tracks the dynamic interaction between each particle and the fluid. The movements of the fluid and the object are directly coupled. A background mesh is designed to fit the geometry of the overall domain. The mesh is designed independently of the presence of the particles except in terms of how fine it must be to track particles of a given size. Each particle is represented by a geometric figure that describes its boundary. This figure overlies the mesh. Nodes are added to the mesh where the particle boundaries intersect the background mesh, increasing the number of nodes contained in each element whose boundary is intersected. These additional nodes are then used to describe and track the particle in the numerical scheme. Appropriate element shape functions are defined to approximate the solution on the elements with extra nodes. The particles are moved through the mesh by moving only the overlying nodes defining the particles. The regular finite element grid remains unchanged. In this method, the mesh does not distort as the particles move. Instead, only the placement of particle-defining nodes changes as the particles move. Element shape functions are updated as the nodes move through the elements. This method is especially suited for models of moderate numbers of moderate-size particles, where the details of the fluid-particle coupling are important. Both the complications of creating finite element meshes around appreciable numbers of particles, and extensive remeshing upon movement of the particles are simplified in this method. PMID:28009377

Acoustic energy transmission in cast iron pipelines

NASA Astrophysics Data System (ADS)

Kiziroglou, Michail E.; Boyle, David E.; Wright, Steven W.; Yeatman, Eric M.

2015-12-01

In this paper we propose acoustic power transfer as a method for the remote powering of pipeline sensor nodes. A theoretical framework of acoustic power propagation in the ceramic transducers and the metal structures is drawn, based on the Mason equivalent circuit. The effect of mounting on the electrical response of piezoelectric transducers is studied experimentally. Using two identical transducer structures, power transmission of 0.33 mW through a 1 m long, 118 mm diameter cast iron pipe, with 8 mm wall thickness is demonstrated, at 1 V received voltage amplitude. A near-linear relationship between input and output voltage is observed. These results show that it is possible to deliver significant power to sensor nodes through acoustic waves in solid structures. The proposed method may enable the implementation of acoustic - powered wireless sensor nodes for structural and operation monitoring of pipeline infrastructure.

High order Nyström method for elastodynamic scattering

NASA Astrophysics Data System (ADS)

Chen, Kun; Gurrala, Praveen; Song, Jiming; Roberts, Ron

2016-02-01

Elastic waves in solids find important applications in ultrasonic non-destructive evaluation. The scattering of elastic waves has been treated using many approaches like the finite element method, boundary element method and Kirchhoff approximation. In this work, we propose a novel accurate and efficient high order Nyström method to solve the boundary integral equations for elastodynamic scattering problems. This approach employs high order geometry description for the element, and high order interpolation for fields inside each element. Compared with the boundary element method, this approach makes the choice of the nodes for interpolation based on the Gaussian quadrature, which renders matrix elements for far field interaction free from integration, and also greatly simplifies the process for singularity and near singularity treatment. The proposed approach employs a novel efficient near singularity treatment that makes the solver able to handle extreme geometries like very thin penny-shaped crack. Numerical results are presented to validate the approach. By using the frequency domain response and performing the inverse Fourier transform, we also report the time domain response of flaw scattering.

Architecture of a spatial data service system for statistical analysis and visualization of regional climate changes

NASA Astrophysics Data System (ADS)

Titov, A. G.; Okladnikov, I. G.; Gordov, E. P.

2017-11-01

The use of large geospatial datasets in climate change studies requires the development of a set of Spatial Data Infrastructure (SDI) elements, including geoprocessing and cartographical visualization web services. This paper presents the architecture of a geospatial OGC web service system as an integral part of a virtual research environment (VRE) general architecture for statistical processing and visualization of meteorological and climatic data. The architecture is a set of interconnected standalone SDI nodes with corresponding data storage systems. Each node runs a specialized software, such as a geoportal, cartographical web services (WMS/WFS), a metadata catalog, and a MySQL database of technical metadata describing geospatial datasets available for the node. It also contains geospatial data processing services (WPS) based on a modular computing backend realizing statistical processing functionality and, thus, providing analysis of large datasets with the results of visualization and export into files of standard formats (XML, binary, etc.). Some cartographical web services have been developed in a system’s prototype to provide capabilities to work with raster and vector geospatial data based on OGC web services. The distributed architecture presented allows easy addition of new nodes, computing and data storage systems, and provides a solid computational infrastructure for regional climate change studies based on modern Web and GIS technologies.

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

Yang, Qingcheng, E-mail: qiy9@pitt.edu; To, Albert C., E-mail: albertto@pitt.edu

Surface effects have been observed to contribute significantly to the mechanical response of nanoscale structures. The newly proposed energy-based coarse-grained atomistic method Multiresolution Molecular Mechanics (MMM) (Yang, To (2015), ) is applied to capture surface effect for nanosized structures by designing a surface summation rule SR{sup S} within the framework of MMM. Combined with previously proposed bulk summation rule SR{sup B}, the MMM summation rule SR{sup MMM} is completed. SR{sup S} and SR{sup B} are consistently formed within SR{sup MMM} for general finite element shape functions. Analogous to quadrature rules in finite element method (FEM), the key idea to themore » good performance of SR{sup MMM} lies in that the order or distribution of energy for coarse-grained atomistic model is mathematically derived such that the number, position and weight of quadrature-type (sampling) atoms can be determined. Mathematically, the derived energy distribution of surface area is different from that of bulk region. Physically, the difference is due to the fact that surface atoms lack neighboring bonding. As such, SR{sup S} and SR{sup B} are employed for surface and bulk domains, respectively. Two- and three-dimensional numerical examples using the respective 4-node bilinear quadrilateral, 8-node quadratic quadrilateral and 8-node hexahedral meshes are employed to verify and validate the proposed approach. It is shown that MMM with SR{sup MMM} accurately captures corner, edge and surface effects with less 0.3% degrees of freedom of the original atomistic system, compared against full atomistic simulation. The effectiveness of SR{sup MMM} with respect to high order element is also demonstrated by employing the 8-node quadratic quadrilateral to solve a beam bending problem considering surface effect. In addition, the introduced sampling error with SR{sup MMM} that is analogous to numerical integration error with quadrature rule in FEM is very small. - Highlights: • Surface effect captured by Multiresolution Molecular Mechanics (MMM) is presented. • A novel surface summation rule within the framework of MMM is proposed. • Surface, corner and edges effects are accuterly captured in two and three dimension. • MMM with less 0.3% degrees of freedom of atomistics reproduces atomistic results.« less

Biomechanics Simulations Using Cubic Hermite Meshes with Extraordinary Nodes for Isogeometric Cardiac Modeling

PubMed Central

Gonzales, Matthew J.; Sturgeon, Gregory; Segars, W. Paul; McCulloch, Andrew D.

2016-01-01

Cubic Hermite hexahedral finite element meshes have some well-known advantages over linear tetrahedral finite element meshes in biomechanical and anatomic modeling using isogeometric analysis. These include faster convergence rates as well as the ability to easily model rule-based anatomic features such as cardiac fiber directions. However, it is not possible to create closed complex objects with only regular nodes; these objects require the presence of extraordinary nodes (nodes with 3 or >= 5 adjacent elements in 2D) in the mesh. The presence of extraordinary nodes requires new constraints on the derivatives of adjacent elements to maintain continuity. We have developed a new method that uses an ensemble coordinate frame at the nodes and a local-to-global mapping to maintain continuity. In this paper, we make use of this mapping to create cubic Hermite models of the human ventricles and a four-chamber heart. We also extend the methods to the finite element equations to perform biomechanics simulations using these meshes. The new methods are validated using simple test models and applied to anatomically accurate ventricular meshes with valve annuli to simulate complete cardiac cycle simulations. PMID:27182096

Three-Dimensional Finite Element Analysis of Sheet-Pile Cellular Cofferdams

DTIC Science & Technology

1992-04-01

requirements were in selecting the shell element for this study: * Nodes only at the midsurface of the element. * Higher-order shape functions to...on orthogonal curvilinear coordinate (shell coordinates) system with the ref- erence surface of the element midsurface (Figure 4.13). The formulation...element was selected which allows for: * Nodes at the midsurface of the element only. 150 CHAPTER 4. ADDITIONS TO THE ELEMENT LIBRARY " Higher-order

Nonlinear Dynamic Responses of Composite Rotor Blades

DTIC Science & Technology

1988-08-01

models. QHD40 is an eight-noded plate element with seven degrees of freedom (three midsurface displacements, two rotations and two higher order terms for...in-plane displacements) per corner node and three degrees of freedom (transverse midsurface displacement and two rotations) per mid-state node. QHD48...and QHD48S are eight-noded plate and shell elements respectively, with six degrees of freedom (three midsurface displacements and three rotations

A new discrete Kirchhoff-Mindlin element based on Mindlin-Reissner plate theory and assumed shear strain fields. I - An extended DKT element for thick-plate bending analysis. II - An extended DKQ element for thick-plate bending analysis

NASA Astrophysics Data System (ADS)

Katili, Irwan

1993-06-01

A new three-node nine-degree-of-freedom triangular plate bending element is proposed which is valid for the analysis of both thick and thin plates. The element, called the discrete Kirchhoff-Mindlin triangle (DKMT), has a proper rank, passes the patch test for thin and thick plates in an arbitrary mesh, and is free of shear locking. As an extension of the DKMT element, a four-node element with 3 degrees of freedom per node is developed. The element, referred to as DKMQ (discrete Kirchhoff-Mindlin quadrilateral) is found to provide good results for both thin and thick plates without any compatibility problems.

International Space Station Node 1 is moved for leak test

NASA Technical Reports Server (NTRS)

1998-01-01

Node 1, the first element for the International Space Station, and attached Pressurized Mating Adapter-1 continue with prelaunch preparation activities at KSC's Space Station Processing Facility. Node 1 is a connecting passageway to the living and working areas of the space station. The node is being removed from the element rotation stand, or test stand, where it underwent an interim weight and center of gravity determination. (The final determination is planned to be performed prior to transporting Node 1 to the launch pad.) Now the node is being moved to the Shuttle payload transportation canister, where the doors will be closed for a two-week leak check. Node 1 is scheduled to fly on STS-88.

Extension-torsion coupling behavior of advanced composite tilt-rotor blades

NASA Technical Reports Server (NTRS)

Kosmatka, J. B.

1989-01-01

An analytic model was developed to study the extension-bend-twist coupling behavior of an advanced composite helicopter or tilt-rotor blade. The outer surface of the blade is defined by rotating an arbitrary cross section about an initial twist axis. The cross section can be nonhomogeneous and composed of generally anisotropic materials. The model is developed based upon a three dimensional elasticity approach that is recast as a coupled two-dimensional boundary value problem defined in a curvilinear coordinate system. Displacement solutions are written in terms of known functions that represent extension, bending, and twisting and unknown functions for local cross section deformations. The unknown local deformation functions are determined by applying the principle of minimum potential energy to the discretized two-dimensional cross section. This is an application of the Ritz method, where the trial function family is the displacement field associated with a finite element (8-node isoparametric quadrilaterals) representation of the section. A computer program was written where the cross section is discretized into 8-node quadrilateral subregions. Initially the program was verified using previously published results (both three-dimensional elasticity and technical beam theory) for pretwisted isotropic bars with an elliptical cross section. In addition, solid and thin-wall multi-cell NACA-0012 airfoil sections were analyzed to illustrate the pronounced effects that pretwist, initial twist axis location, and spar location has on coupled behavior. Currently, a series of advanced composite airfoils are being modeled in order to assess how the use of laminated composite materials interacts with pretwist to alter the coupling behavior of the blade. These studies will investigate the use of different ply angle orientations and the use of symmetric versus unsymmetric laminates.

High-performance parallel processors based on star-coupled wavelength division multiplexing optical interconnects

DOEpatents

Deri, Robert J.; DeGroot, Anthony J.; Haigh, Ronald E.

2002-01-01

As the performance of individual elements within parallel processing systems increases, increased communication capability between distributed processor and memory elements is required. There is great interest in using fiber optics to improve interconnect communication beyond that attainable using electronic technology. Several groups have considered WDM, star-coupled optical interconnects. The invention uses a fiber optic transceiver to provide low latency, high bandwidth channels for such interconnects using a robust multimode fiber technology. Instruction-level simulation is used to quantify the bandwidth, latency, and concurrency required for such interconnects to scale to 256 nodes, each operating at 1 GFLOPS performance. Performance scales have been shown to .apprxeq.100 GFLOPS for scientific application kernels using a small number of wavelengths (8 to 32), only one wavelength received per node, and achievable optoelectronic bandwidth and latency.

Node 1 and PMA-1 are moved for weight and center of gravity determination

NASA Technical Reports Server (NTRS)

1998-01-01

Node 1, the first U.S. element for the International Space Station, and Pressurized Mating Adapter-1 (PMA-1) continue with prelaunch preparation activities at KSC's Space Station Processing Facility. Node 1 is a connecting passageway to the living and working areas of the space station. The node and PMA-1 are being moved to an element rotation stand, or test stand, where they will undergo an interim weight and center of gravity determination. The final determination is planned to be performed prior to transporting Node 1 to the launch pad. Node 1 is scheduled to fly on STS-88.

Energy-efficient Data-intensive Computing with a Fast Array of Wimpy Nodes

DTIC Science & Technology

2011-10-01

sleep states provided by the Intel Atom chipset (between 2– 4 W) to turn off machines and migrate workloads during idle periods and low utilization...are generated. 81 0 200 400 600 800 1000 1200 IO PS in T ho us an ds Threads 1 2 4 8 16 32 64 Solid = Multi, Dashed = Single QD/T = 1 QD/T = 2...600 700 800 900 1000 L a te n c y ( in u s ) K Lookups/sec R1G8 R2G8 R4G8 R8G8 R16G8 R32G8 R64G8 (a) Multiget=2 (b) Multiget= 4 (c) Multiget=8 0

Toward efficient biomechanical-based deformable image registration of lungs for image-guided radiotherapy

NASA Astrophysics Data System (ADS)

Al-Mayah, Adil; Moseley, Joanne; Velec, Mike; Brock, Kristy

2011-08-01

Both accuracy and efficiency are critical for the implementation of biomechanical model-based deformable registration in clinical practice. The focus of this investigation is to evaluate the potential of improving the efficiency of the deformable image registration of the human lungs without loss of accuracy. Three-dimensional finite element models have been developed using image data of 14 lung cancer patients. Each model consists of two lungs, tumor and external body. Sliding of the lungs inside the chest cavity is modeled using a frictionless surface-based contact model. The effect of the type of element, finite deformation and elasticity on the accuracy and computing time is investigated. Linear and quadrilateral tetrahedral elements are used with linear and nonlinear geometric analysis. Two types of material properties are applied namely: elastic and hyperelastic. The accuracy of each of the four models is examined using a number of anatomical landmarks representing the vessels bifurcation points distributed across the lungs. The registration error is not significantly affected by the element type or linearity of analysis, with an average vector error of around 2.8 mm. The displacement differences between linear and nonlinear analysis methods are calculated for all lungs nodes and a maximum value of 3.6 mm is found in one of the nodes near the entrance of the bronchial tree into the lungs. The 95 percentile of displacement difference ranges between 0.4 and 0.8 mm. However, the time required for the analysis is reduced from 95 min in the quadratic elements nonlinear geometry model to 3.4 min in the linear element linear geometry model. Therefore using linear tetrahedral elements with linear elastic materials and linear geometry is preferable for modeling the breathing motion of lungs for image-guided radiotherapy applications.

Simulation of a Single-Element Lean-Direct Injection Combustor Using a Polyhedral Mesh Derived from Hanging-Node Elements

NASA Technical Reports Server (NTRS)

Wey, Thomas; Liu, Nan-Suey

2013-01-01

This paper summarizes the procedures of generating a polyhedral mesh derived from hanging-node elements as well as presents sample results from its application to the numerical solution of a single element lean direct injection (LDI) combustor using an open-source version of the National Combustion Code (NCC).

International Space Station Node 1 is moved for leak test

NASA Technical Reports Server (NTRS)

1998-01-01

Node 1, the first element for the International Space Station, and attached Pressurized Mating Adapter-1 continue with prelaunch preparation activities at KSC's Space Station Processing Facility. Node 1 is a connecting passageway to the living and working areas of the space station. The node is seen here being moved into the Shuttle payload transportation canister, where the doors will be closed for a two-week leak check. The node was moved to the canister from the element rotation stand, or test stand, where it underwent an interim weight and center of gravity determination. The final determination is planned to be performed prior to transporting Node 1 to the launch pad. Node 1 is scheduled to fly on STS-88.

International Space Station Node 1 is moved for leak test

NASA Technical Reports Server (NTRS)

1998-01-01

Node 1, the first U.S. element for the International Space Station, and attached Pressurized Mating Adapter-1 continue with prelaunch preparation activities at KSC's Space Station Processing Facility. Node 1 is a connecting passageway to the living and working areas of the space station. The node and PMA-1 are being removed from the element rotation stand, or test stand, where they underwent an interim weight and center of gravity determination. (The final determination is planned to be performed prior to transporting Node 1 to the launch pad.) Now the node is being moved to the Shuttle payload transportation canister, where the doors will be closed for a two-week leak check. Node 1 is scheduled to fly on STS-88.

Hyperswitch Network For Hypercube Computer

NASA Technical Reports Server (NTRS)

Chow, Edward; Madan, Herbert; Peterson, John

1989-01-01

Data-driven dynamic switching enables high speed data transfer. Proposed hyperswitch network based on mixed static and dynamic topologies. Routing header modified in response to congestion or faults encountered as path established. Static topology meets requirement if nodes have switching elements that perform necessary routing header revisions dynamically. Hypercube topology now being implemented with switching element in each computer node aimed at designing very-richly-interconnected multicomputer system. Interconnection network connects great number of small computer nodes, using fixed hypercube topology, characterized by point-to-point links between nodes.

Effectiveness of Rotation-free Triangular and Quadrilateral Shell Elements in Sheet-metal Forming Simulations

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

Brunet, M.; Sabourin, F.

2005-08-05

This paper is concerned with the effectiveness of triangular 3-node shell element without rotational d.o.f. and the extension to a new 4-node quadrilateral shell element called S4 with only 3 translational degrees of freedom per node and one-point integration. The curvatures are computed resorting to the surrounding elements. Extension from rotation-free triangular element to a quadrilateral element requires internal curvatures in order to avoid singular bending stiffness. Two numerical examples with regular and irregular meshes are performed to show the convergence and accuracy. Deep-drawing of a box, spring-back analysis of a U-shape strip sheet and the crash simulation of amore » beam-box complete the demonstration of the bending capabilities of the proposed rotation-free triangular and quadrilateral elements.« less

Lunar tidal acceleration obtained from satellite-derived ocean tide parameters

NASA Technical Reports Server (NTRS)

Goad, C. C.; Douglas, B. C.

1978-01-01

One hundred sets of mean elements of GEOS-3 computed at 2-day intervals yielded observation equations for the M sub 2 ocean tide from the long periodic variations of the inclination and node of the orbit. The 2nd degree Love number was given the value k sub 2 = 0.30 and the solid tide phase angle was taken to be zero. Combining obtained equations with results for the satellite 1967-92A gives the M sub 2 ocean tide parameter values. Under the same assumption of zero solid tide phase lag, the lunar tidal acceleration was found mostly due to the C sub 22 term in the expansion of the M sub 2 tide with additional small contributions from the 0 sub 1 and N sub 2 tides. Using Lambeck's (1975) estimates for the latter, the obtained acceleration in lunar longitudal in excellent agreement with the most recent determinations from ancient and modern astronomical data.

Method of generating a surface mesh

DOEpatents

Shepherd, Jason F [Albuquerque, NM; Benzley, Steven [Provo, UT; Grover, Benjamin T [Tracy, CA

2008-03-04

A method and machine-readable medium provide a technique to generate and modify a quadrilateral finite element surface mesh using dual creation and modification. After generating a dual of a surface (mesh), a predetermined algorithm may be followed to generate and modify a surface mesh of quadrilateral elements. The predetermined algorithm may include the steps of generating two-dimensional cell regions in dual space, determining existing nodes in primal space, generating new nodes in the dual space, and connecting nodes to form the quadrilateral elements (faces) for the generated and modifiable surface mesh.

Updates to Simulation of a Single-Element Lean-Direct Injection Combustor Using a Polyhedral Mesh Derived From Hanging-Node Elements

NASA Technical Reports Server (NTRS)

Wey, Changju Thomas; Liu, Nan-Suey

2014-01-01

This paper summarizes the procedures of inserting a thin-layer mesh to existing inviscid polyhedral mesh either with or without hanging-node elements as well as presents sample results from its applications to the numerical solution of a single-element LDI combustor using a releasable edition of the National Combustion Code (NCC).

Updates to Simulation of a Single-Element Lean-Direct Injection Combustor Using a Polyhedral Mesh Derived from Hanging-Node Elements

NASA Technical Reports Server (NTRS)

Wey, Thomas; Liu, Nan-Suey

2014-01-01

This paper summarizes the procedures of inserting a thin-layer mesh to existing inviscid polyhedral mesh either with or without hanging-node elements as well as presents sample results from its applications to the numerical solution of a single-element LDI combustor using a releasable edition of the National Combustion Code (NCC).

Node-controlled allocation of mineral elements in Poaceae.

PubMed

Yamaji, Naoki; Ma, Jian Feng

2017-10-01

Mineral elements taken up by the roots will be delivered to different organs and tissues depending on their requirements. In Poaceae, this selective distribution is mainly mediated in the nodes, which have highly developed and fully organized vascular systems. Inter-vascular transfer of mineral elements from enlarged vascular bundles to diffuse vascular bundles is required for their preferential distribution to developing tissues and reproductive organs. A number of transporters involved in this inter-vascular transfer processes have been identified mainly in rice. They are localized at the different cell layers and form an efficient machinery within the node. Furthermore, some these transporters show rapid response to the environmental changes of mineral elements at the protein level. In addition to the node-based transporters, distinct nodal structures including enlarged xylem area, folded plasma membrane of xylem transfer cells and presence of an apoplastic barrier are also required for the efficient inter-vascular transfer. Manipulation of node-based transporters will provide a novel breeding target to improve nutrient use efficiency, productivity, nutritional value and safety in cereal crops. Copyright © 2017 Elsevier Ltd. All rights reserved.

A finite element study of the EIDI system. [Electro-Impulse De-Icing System

NASA Technical Reports Server (NTRS)

Khatkhate, A. A.; Scavuzzo, R. J.; Chu, M. L.

1988-01-01

This paper presents a method for modeling the structural dynamics of an Electro-Impulse De-Icing System, using finite element analyses procedures. A guideline for building a representative finite element model is discussed. Modeling was done initially using four noded cubic elements, four noded isoparametric plate elements and eight noded isoparametric shell elements. Due to the size of the problem and due to the underestimation of shear stress results when compared to previous analytical work an approximate model was created to predict possible areas of shedding of ice. There appears to be good agreement with the test data provided by The Boeing Commercial Airplane Company. Thus these initial results of this method were found to be encouraging. Additional analytical work and comparison with experiment is needed in order to completely evaluate this approach.

surf3d: A 3-D finite-element program for the analysis of surface and corner cracks in solids subjected to mode-1 loadings

NASA Technical Reports Server (NTRS)

Raju, I. S.; Newman, J. C., Jr.

1993-01-01

A computer program, surf3d, that uses the 3D finite-element method to calculate the stress-intensity factors for surface, corner, and embedded cracks in finite-thickness plates with and without circular holes, was developed. The cracks are assumed to be either elliptic or part eliptic in shape. The computer program uses eight-noded hexahedral elements to model the solid. The program uses a skyline storage and solver. The stress-intensity factors are evaluated using the force method, the crack-opening displacement method, and the 3-D virtual crack closure methods. In the manual the input to and the output of the surf3d program are described. This manual also demonstrates the use of the program and describes the calculation of the stress-intensity factors. Several examples with sample data files are included with the manual. To facilitate modeling of the user's crack configuration and loading, a companion program (a preprocessor program) that generates the data for the surf3d called gensurf was also developed. The gensurf program is a three dimensional mesh generator program that requires minimal input and that builds a complete data file for surf3d. The program surf3d is operational on Unix machines such as CRAY Y-MP, CRAY-2, and Convex C-220.

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra aids in Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

NASA Image and Video Library

2004-02-03

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra aids in Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers check over the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

NASA Image and Video Library

2004-02-03

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers check over the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

A parallel algorithm for generation and assembly of finite element stiffness and mass matrices

NASA Technical Reports Server (NTRS)

Storaasli, O. O.; Carmona, E. A.; Nguyen, D. T.; Baddourah, M. A.

1991-01-01

A new algorithm is proposed for parallel generation and assembly of the finite element stiffness and mass matrices. The proposed assembly algorithm is based on a node-by-node approach rather than the more conventional element-by-element approach. The new algorithm's generality and computation speed-up when using multiple processors are demonstrated for several practical applications on multi-processor Cray Y-MP and Cray 2 supercomputers.

Fault current limiter and alternating current circuit breaker

DOEpatents

Boenig, Heinrich J.

1998-01-01

A solid-state circuit breaker and current limiter for a load served by an alternating current source having a source impedance, the solid-state circuit breaker and current limiter comprising a thyristor bridge interposed between the alternating current source and the load, the thyristor bridge having four thyristor legs and four nodes, with a first node connected to the alternating current source, and a second node connected to the load. A coil is connected from a third node to a fourth node, the coil having an impedance of a value calculated to limit the current flowing therethrough to a predetermined value. Control means are connected to the thyristor legs for limiting the alternating current flow to the load under fault conditions to a predetermined level, and for gating the thyristor bridge under fault conditions to quickly reduce alternating current flowing therethrough to zero and thereafter to maintain the thyristor bridge in an electrically open condition preventing the alternating current from flowing therethrough for a predetermined period of time.

Fault current limiter and alternating current circuit breaker

DOEpatents

Boenig, H.J.

1998-03-10

A solid-state circuit breaker and current limiter are disclosed for a load served by an alternating current source having a source impedance, the solid-state circuit breaker and current limiter comprising a thyristor bridge interposed between the alternating current source and the load, the thyristor bridge having four thyristor legs and four nodes, with a first node connected to the alternating current source, and a second node connected to the load. A coil is connected from a third node to a fourth node, the coil having an impedance of a value calculated to limit the current flowing therethrough to a predetermined value. Control means are connected to the thyristor legs for limiting the alternating current flow to the load under fault conditions to a predetermined level, and for gating the thyristor bridge under fault conditions to quickly reduce alternating current flowing therethrough to zero and thereafter to maintain the thyristor bridge in an electrically open condition preventing the alternating current from flowing therethrough for a predetermined period of time. 9 figs.

Highly accurate symplectic element based on two variational principles

NASA Astrophysics Data System (ADS)

Qing, Guanghui; Tian, Jia

2018-02-01

For the stability requirement of numerical resultants, the mathematical theory of classical mixed methods are relatively complex. However, generalized mixed methods are automatically stable, and their building process is simple and straightforward. In this paper, based on the seminal idea of the generalized mixed methods, a simple, stable, and highly accurate 8-node noncompatible symplectic element (NCSE8) was developed by the combination of the modified Hellinger-Reissner mixed variational principle and the minimum energy principle. To ensure the accuracy of in-plane stress results, a simultaneous equation approach was also suggested. Numerical experimentation shows that the accuracy of stress results of NCSE8 are nearly the same as that of displacement methods, and they are in good agreement with the exact solutions when the mesh is relatively fine. NCSE8 has advantages of the clearing concept, easy calculation by a finite element computer program, higher accuracy and wide applicability for various linear elasticity compressible and nearly incompressible material problems. It is possible that NCSE8 becomes even more advantageous for the fracture problems due to its better accuracy of stresses.

Element fracture technique for hypervelocity impact simulation

NASA Astrophysics Data System (ADS)

Zhang, Xiao-tian; Li, Xiao-gang; Liu, Tao; Jia, Guang-hui

2015-05-01

Hypervelocity impact dynamics is the theoretical support of spacecraft shielding against space debris. The numerical simulation has become an important approach for obtaining the ballistic limits of the spacecraft shields. Currently, the most widely used algorithm for hypervelocity impact is the smoothed particle hydrodynamics (SPH). Although the finite element method (FEM) is widely used in fracture mechanics and low-velocity impacts, the standard FEM can hardly simulate the debris cloud generated by hypervelocity impact. This paper presents a successful application of the node-separation technique for hypervelocity impact debris cloud simulation. The node-separation technique assigns individual/coincident nodes for the adjacent elements, and it applies constraints to the coincident node sets in the modeling step. In the explicit iteration, the cracks are generated by releasing the constrained node sets that meet the fracture criterion. Additionally, the distorted elements are identified from two aspects - self-piercing and phase change - and are deleted so that the constitutive computation can continue. FEM with the node-separation technique is used for thin-wall hypervelocity impact simulations. The internal structures of the debris cloud in the simulation output are compared with that in the test X-ray graphs under different material fracture criteria. It shows that the pressure criterion is more appropriate for hypervelocity impact. The internal structures of the debris cloud are also simulated and compared under different thickness-to-diameter ratios (t/D). The simulation outputs show the same spall pattern with the tests. Finally, the triple-plate impact case is simulated with node-separation FEM.

Anomaly Detection for Data Reduction in an Unattended Ground Sensor (UGS) Field

DTIC Science & Technology

2014-09-01

information (shown with solid lines in the diagram). Typically, this would be a mobile ad - hoc network (MANET). The clusters are connected to other nodes...interquartile ranges MANET mobile ad - hoc network OSUS Open Standards for Unattended Sensors TOC tactical operations center UAVs unmanned aerial vehicles...19b. TELEPHONE NUMBER (Include area code ) 301-394-1221 Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 iii Contents List of

Construction and validation of a three-dimensional finite element model of degenerative scoliosis.

PubMed

Zheng, Jie; Yang, Yonghong; Lou, Shuliang; Zhang, Dongsheng; Liao, Shenghui

2015-12-24

With the aging of the population, degenerative scoliosis (DS) incidence rate is increasing. In recent years, increasing research on this topic has been carried out, yet biomechanical research on the subject is seldom seen and in vitro biomechanical model of DS nearly cannot be available. The objective of this study was to develop and validate a complete three-dimensional finite element model of DS in order to build the digital platform for further biomechanical study. A 55-year-old female DS patient (Suer Pan, ID number was P141986) was selected for this study. This study was performed in accordance with the ethical standards of Declaration of Helsinki and its amendments and was approved by the local ethics committee (117 hospital of PLA ethics committee). Spiral computed tomography (CT) scanning was conducted on the patient's lumbar spine from the T12 to S1. CT images were then imported into a finite element modeling system. A three-dimensional solid model was then formed from segmentation of the CT scan. The three-dimensional model of each vertebra was then meshed, and material properties were assigned to each element according to the pathological characteristics of DS. Loads and boundary conditions were then applied in such a manner as to simulate in vitro biomechanical experiments conducted on lumbar segments. The results of the model were then compared with experimental results in order to validate the model. An integral three-dimensional finite element model of DS was built successfully, consisting of 113,682 solid elements, 686 cable elements, 33,329 shell elements, 4968 target elements, 4968 contact elements, totaling 157,635 elements, and 197,374 nodes. The model accurately described the physical features of DS and was geometrically similar to the object of study. The results of analysis with the finite element model agreed closely with in vitro experiments, validating the accuracy of the model. The three-dimensional finite element model of DS built in this study is clear, reliable, and effective for further biomechanical simulation study of DS.

Connecting node and method for constructing a connecting node

NASA Technical Reports Server (NTRS)

Johnson, Christopher J. (Inventor); Raboin, Jasen L. (Inventor); Spexarth, Gary R. (Inventor)

2011-01-01

A connecting node comprises a polyhedral structure comprising a plurality of panels joined together at its side edges to form a spherical approximation, wherein at least one of the plurality of panels comprises a faceted surface being constructed with a passage for integrating with one of a plurality of elements comprising a docking port, a hatch, and a window that is attached to the connecting node. A method for manufacturing a connecting node comprises the steps of providing a plurality of panels, connecting the plurality of panels to form a spherical approximation, wherein each edge of each panel of the plurality is joined to another edge of another panel, and constructing at least one of the plurality of panels to include a passage for integrating at least one of a plurality of elements that may be attached to the connecting node.

Anisotropic constitutive model for nickel base single crystal alloys: Development and finite element implementation

NASA Technical Reports Server (NTRS)

Dame, L. T.; Stouffer, D. C.

1986-01-01

A tool for the mechanical analysis of nickel base single crystal superalloys, specifically Rene N4, used in gas turbine engine components is developed. This is achieved by a rate dependent anisotropic constitutive model implemented in a nonlinear three dimensional finite element code. The constitutive model is developed from metallurigical concepts utilizing a crystallographic approach. A non Schmid's law formulation is used to model the tension/compression asymmetry and orientation dependence in octahedral slip. Schmid's law is a good approximation to the inelastic response of the material in cube slip. The constitutive equations model the tensile behavior, creep response, and strain rate sensitivity of these alloys. Methods for deriving the material constants from standard tests are presented. The finite element implementation utilizes an initial strain method and twenty noded isoparametric solid elements. The ability to model piecewise linear load histories is included in the finite element code. The constitutive equations are accurately and economically integrated using a second order Adams-Moulton predictor-corrector method with a dynamic time incrementing procedure. Computed results from the finite element code are compared with experimental data for tensile, creep and cyclic tests at 760 deg C. The strain rate sensitivity and stress relaxation capabilities of the model are evaluated.

Toxic trace elements in solid airborne particles and ecological risk assessment in the vicinity of local boiler house plants

NASA Astrophysics Data System (ADS)

Talovskaya, Anna V.; Osipova, Nina A.; Yazikov, Egor G.; Shakhova, Tatyana S.

2017-11-01

The article deals with assessment of anthropogenic pollution in vicinity of local boilers using the data on microelement composition of solid airborne particles deposited in snow. The anthropogenic feature of elevated accumulation levels of solid airborne particles deposited in snow in the vicinity of coal-fired boiler house is revealed in elevated concentrations (3-25 higher than background) of Cd, Sb, Mo, Pb, Sr, Ba, Ni, Mo, Zn and Co. In the vicinity oil-fired boiler house the specific elements as parts of solid airborne particles deposited in snow are V, Ni and Sb, as their content exceeds the background from 3 to 8 times. It is determined that the maximum shares in non-carcinogenic human health risk from chronic inhalation of trace elements to the human body in the vicinity of coal-fired boiler house belong to Al, Mn, Cu, Ba, Co, Pb, whereas in the vicinity of oil-fired boiler house - Al, Mn, Cu, Ni, V.

MUSIC algorithm DoA estimation for cooperative node location in mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Warty, Chirag; Yu, Richard Wai; ElMahgoub, Khaled; Spinsante, Susanna

In recent years the technological development has encouraged several applications based on distributed communications network without any fixed infrastructure. The problem of providing a collaborative early warning system for multiple mobile nodes against a fast moving object. The solution is provided subject to system level constraints: motion of nodes, antenna sensitivity and Doppler effect at 2.4 GHz and 5.8 GHz. This approach consists of three stages. The first phase consists of detecting the incoming object using a highly directive two element antenna at 5.0 GHz band. The second phase consists of broadcasting the warning message using a low directivity broad antenna beam using 2× 2 antenna array which then in third phase will be detected by receiving nodes by using direction of arrival (DOA) estimation technique. The DOA estimation technique is used to estimate the range and bearing of the incoming nodes. The position of fast arriving object can be estimated using the MUSIC algorithm for warning beam DOA estimation. This paper is mainly intended to demonstrate the feasibility of early detection and warning system using a collaborative node to node communication links. The simulation is performed to show the behavior of detecting and broadcasting antennas as well as performance of the detection algorithm. The idea can be further expanded to implement commercial grade detection and warning system

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra (facing camera) aids in Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

NASA Image and Video Library

2004-02-03

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra (facing camera) aids in Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra talks to a technician (off-camera) during Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

NASA Image and Video Library

2004-02-03

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra talks to a technician (off-camera) during Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

An Element-Based Concurrent Partitioner for Unstructured Finite Element Meshes

NASA Technical Reports Server (NTRS)

Ding, Hong Q.; Ferraro, Robert D.

1996-01-01

A concurrent partitioner for partitioning unstructured finite element meshes on distributed memory architectures is developed. The partitioner uses an element-based partitioning strategy. Its main advantage over the more conventional node-based partitioning strategy is its modular programming approach to the development of parallel applications. The partitioner first partitions element centroids using a recursive inertial bisection algorithm. Elements and nodes then migrate according to the partitioned centroids, using a data request communication template for unpredictable incoming messages. Our scalable implementation is contrasted to a non-scalable implementation which is a straightforward parallelization of a sequential partitioner.

A Stirling engine analysis method based upon moving gas nodes

NASA Technical Reports Server (NTRS)

Martini, W. R.

1986-01-01

A Lagrangian nodal analysis method for Stirling engines (SEs) is described, validated, and applied to a conventional SE and an isothermalized SE (with fins in the hot and cold spaces). The analysis employs a constant-mass gas node (which moves with respect to the solid nodes during each time step) instead of the fixed gas nodes of Eulerian analysis. The isothermalized SE is found to have efficiency only slightly greater than that of a conventional SE.

Method of modifying a volume mesh using sheet extraction

DOEpatents

Borden, Michael J [Albuquerque, NM; Shepherd, Jason F [Albuquerque, NM

2007-02-20

A method and machine-readable medium provide a technique to modify a hexahedral finite element volume mesh using dual generation and sheet extraction. After generating a dual of a volume stack (mesh), a predetermined algorithm may be followed to modify the volume mesh of hexahedral elements. The predetermined algorithm may include the steps of determining a sheet of hexahedral mesh elements, generating nodes for merging, and merging the nodes to delete the sheet of hexahedral mesh elements and modify the volume mesh.

Node 3 Relocation Environmental Control and Life Support System Modification Kit Verification and Updated Status

NASA Technical Reports Server (NTRS)

Williams, David E.; Spector Lawrence N.

2010-01-01

Node 1 (Unity) flew to International Space Station (ISS) on Flight 2A. Node 1 was the first module of the United States On-Orbit Segment (USOS) launched to ISS. The Node 1 ISS Environmental Control and Life Support (ECLS) design featured limited ECLS capability. The main purpose of Node 1 was to provide internal storage by providing four stowage rack locations within the module and to allow docking of multiple modules and a truss segment to it. The ECLS subsystems inside Node 1 were routed through the element prior to launch to allow for easy integration of the attached future elements, particularly the Habitation Module which was planned to be located at the nadir docking port of Node 1. After Node I was on-orbit, the Program decided not to launch the Habitation Module and instead, to replace it with Node 3 (Tranquility). In 2007, the Program became concerned with a potential Russian docking port approach issue for the Russian FGB nadir docking port after Node 3 is attached to Node 1. To solve this concern the Program decided to relocate Node 3 from Node I nadir to Node 1 port. To support the movement of Node 3 the Program decided to build a modification kit for Node 1, an on-orbit feedthrough leak test device, and new vestibule jumpers to support the ECLS part of the relocation. This paper provides a design overview of the modification kit for Node 1, a summary of the Node 1 ECLS re-verification to support the Node 3 relocation from Node 1 nadir to Node 1 port, and a status of the ECLS modification kit installation into Node 1.

Application of a hybrid generation/utility assessment heuristic to a class of scheduling problems

NASA Technical Reports Server (NTRS)

Heyward, Ann O.

1989-01-01

A two-stage heuristic solution approach for a class of multiobjective, n-job, 1-machine scheduling problems is described. Minimization of job-to-job interference for n jobs is sought. The first stage generates alternative schedule sequences by interchanging pairs of schedule elements. The set of alternative sequences can represent nodes of a decision tree; each node is reached via decision to interchange job elements. The second stage selects the parent node for the next generation of alternative sequences through automated paired comparison of objective performance for all current nodes. An application of the heuristic approach to communications satellite systems planning is presented.

Global interrupt and barrier networks

DOEpatents

Blumrich, Matthias A.; Chen, Dong; Coteus, Paul W.; Gara, Alan G.; Giampapa, Mark E; Heidelberger, Philip; Kopcsay, Gerard V.; Steinmacher-Burow, Burkhard D.; Takken, Todd E.

2008-10-28

A system and method for generating global asynchronous signals in a computing structure. Particularly, a global interrupt and barrier network is implemented that implements logic for generating global interrupt and barrier signals for controlling global asynchronous operations performed by processing elements at selected processing nodes of a computing structure in accordance with a processing algorithm; and includes the physical interconnecting of the processing nodes for communicating the global interrupt and barrier signals to the elements via low-latency paths. The global asynchronous signals respectively initiate interrupt and barrier operations at the processing nodes at times selected for optimizing performance of the processing algorithms. In one embodiment, the global interrupt and barrier network is implemented in a scalable, massively parallel supercomputing device structure comprising a plurality of processing nodes interconnected by multiple independent networks, with each node including one or more processing elements for performing computation or communication activity as required when performing parallel algorithm operations. One multiple independent network includes a global tree network for enabling high-speed global tree communications among global tree network nodes or sub-trees thereof. The global interrupt and barrier network may operate in parallel with the global tree network for providing global asynchronous sideband signals.

A distributed transmit beamforming synchronization strategy for multi-element radar systems

NASA Astrophysics Data System (ADS)

Xiao, Manlin; Li, Xingwen; Xu, Jikang

2017-02-01

The distributed transmit beamforming has recently been discussed as an energy-effective technique in wireless communication systems. A common ground of various techniques is that the destination node transmits a beacon signal or feedback to assist source nodes to synchronize signals. However, this approach is not appropriate for a radar system since the destination is a non-cooperative target of an unknown location. In our paper, we propose a novel synchronization strategy for a distributed multiple-element beamfoming radar system. Source nodes estimate parameters of beacon signals transmitted from others to get their local synchronization information. The channel information of the phase propagation delay is transmitted to nodes via the reflected beacon signals as well. Next, each node generates appropriate parameters to form a beamforming signal at the target. Transmit beamforming signals of all nodes will combine coherently at the target compensating for different propagation delay. We analyse the influence of the local oscillation accuracy and the parameter estimation errors on the performance of the proposed synchronization scheme. The results of numerical simulations illustrate that this synchronization scheme is effective to enable the transmit beamforming in a distributed multi-element radar system.

[Determination of process variable pH in solid-state fermentation by FT-NIR spectroscopy and extreme learning machine (ELM)].

PubMed

Liu, Guo-hai; Jiang, Hui; Xiao, Xia-hong; Zhang, Dong-juan; Mei, Cong-li; Ding, Yu-han

2012-04-01

Fourier transform near-infrared (FT-NIR) spectroscopy was attempted to determine pH, which is one of the key process parameters in solid-state fermentation of crop straws. First, near infrared spectra of 140 solid-state fermented product samples were obtained by near infrared spectroscopy system in the wavelength range of 10 000-4 000 cm(-1), and then the reference measurement results of pH were achieved by pH meter. Thereafter, the extreme learning machine (ELM) was employed to calibrate model. In the calibration model, the optimal number of PCs and the optimal number of hidden-layer nodes of ELM network were determined by the cross-validation. Experimental results showed that the optimal ELM model was achieved with 1040-1 topology construction as follows: R(p) = 0.961 8 and RMSEP = 0.104 4 in the prediction set. The research achievement could provide technological basis for the on-line measurement of the process parameters in solid-state fermentation.

Prediction of wrinklings and porosities of thermoplastic composits after thermostamping

NASA Astrophysics Data System (ADS)

Hamila, Nahiene; Guzman-Maldonado, Eduardo; Xiong, Hu; Wang, Peng; Boisse, Philippe; Bikard, Jerome

2018-05-01

During thermoforming process, the consolidation deformation mode of thermoplastic prepregs is one of the key deformation modes especially in the consolidation step, where the two resin flow phenomena: resin percolation and transverse squeeze flow, play an important role. This occurs a viscosity behavior for consolidation mode. Based on a visco-hyper-elastic model for the characterization of thermoplastic prepregs proposed by Guzman, which involves different independent modes of deformation: elongation mode, bending mode with thermo-dependent, and viscoelastic in-plan shearing mode with thermo-dependent, a viscoelastic model completed with consolidation behavior will be presented in this paper. A completed three-dimensional mechanical behavior with compaction effect for thermoplastic pre-impregnated composites is constituted, and the associated parameters are identified by compaction test. Moreover, a seven-node prismatic solid-shell finite element approach is used for the forming simulation. To subdue transverse shear locking, an intermediate material frame related to the element sides is introduced in order to fix nodal transverse shear strain components. Indeed, the enhanced assumed strain method and a reduced integration scheme are combined offering a linear varying strain field along the thickness direction to circumvent thickness locking, and an hourglass stabilization procedure is employed in order to correct the element's rank deficiency for pinching. An additional node is added at the center providing a quadratic interpolation of the displacement in the thickness direction. The predominance of this element is the ability of three dimensional analysis, especially for the transverse stress existence through the thickness of material, which is essential for the consolidation modelling. Finally, an intimate contact model is employed to predict the evolution of the consolidation which permits the microstructure prediction of void presented through the prepreg. Several tests including a thermoforming test are launched to evaluate the consolidation model and the accuracy of the proposed element.

Acta Aeronautica et Astronautica Sinica,

DTIC Science & Technology

1983-07-28

substructural analysis in modal synthesis - two improved substructural assembling techniques 49 9-node quadrilateral isoparametric element 64 Application of laser...Time from Service Data, J. Aircraft, Vol. 15, No. 11, 1978. 48 MULTI-LEVEL SUBSTRUCTURAL ANALYSIS IN MODAL SYNTHESIS -- TWO IMPROVED SUBSTRUCTURAL...34 Modal Synthesis in Structural Dynamic Analysis ," Naching Institute of Aeronautics and Astronautics, 1979. 62a 8. Chang Te-wen, "Free-Interface Modal

Node 3 Relocation Environmental Control and Life Support System Modification Kit Verification and Updated Status

NASA Technical Reports Server (NTRS)

Williams, David E.; Spector, Lawrence N.

2009-01-01

Node 1 (Unity) flew to International Space Station (ISS) on Flight 2A. Node 1 was the first module of the United States On-Orbit Segment (USOS) launched to ISS. The Node 1 ISS Environmental Control and Life Support (ECLS) design featured limited ECLS capability. The main purpose of Node 1 was to provide internal storage by providing four stowage rack locations within the module and to allow docking of multiple modules and a truss segment to it. The ECLS subsystems inside Node 1 were routed through the element prior to launch to allow for easy integration of the attached future elements, particularly the Habitation Module which was planned to be located at the nadir docking port of Node 1. After Node 1 was on-orbit, the Program decided not to launch the Habitation Module and instead, to replace it with Node 3 (Tranquility). In 2007, the Program became concerned with a potential Russian docking port approach issue for the Russian FGB nadir docking port after Node 3 is attached to Node 1. To solve this concern the Program decided to relocate Node 3 from Node 1 nadir to Node 1 port. To support the movement of Node 3 the Program decided to build a modification kit for Node 1, an on-orbit feedthrough leak test device, and new vestibule jumpers to support the ECLS part of the relocation. This paper provides a design overview of the modification kit, a summary of the Node 1 ECLS re-verification to support the Node 3 relocation from Node 1 nadir to Node 1 port, and a status of the ECLS modification kit installation into Node 1.

The node-weighted Steiner tree approach to identify elements of cancer-related signaling pathways.

PubMed

Sun, Yahui; Ma, Chenkai; Halgamuge, Saman

2017-12-28

Cancer constitutes a momentous health burden in our society. Critical information on cancer may be hidden in its signaling pathways. However, even though a large amount of money has been spent on cancer research, some critical information on cancer-related signaling pathways still remains elusive. Hence, new works towards a complete understanding of cancer-related signaling pathways will greatly benefit the prevention, diagnosis, and treatment of cancer. We propose the node-weighted Steiner tree approach to identify important elements of cancer-related signaling pathways at the level of proteins. This new approach has advantages over previous approaches since it is fast in processing large protein-protein interaction networks. We apply this new approach to identify important elements of two well-known cancer-related signaling pathways: PI3K/Akt and MAPK. First, we generate a node-weighted protein-protein interaction network using protein and signaling pathway data. Second, we modify and use two preprocessing techniques and a state-of-the-art Steiner tree algorithm to identify a subnetwork in the generated network. Third, we propose two new metrics to select important elements from this subnetwork. On a commonly used personal computer, this new approach takes less than 2 s to identify the important elements of PI3K/Akt and MAPK signaling pathways in a large node-weighted protein-protein interaction network with 16,843 vertices and 1,736,922 edges. We further analyze and demonstrate the significance of these identified elements to cancer signal transduction by exploring previously reported experimental evidences. Our node-weighted Steiner tree approach is shown to be both fast and effective to identify important elements of cancer-related signaling pathways. Furthermore, it may provide new perspectives into the identification of signaling pathways for other human diseases.

Numerical Modeling of Saturated Boiling in a Heated Tube

NASA Technical Reports Server (NTRS)

Majumdar, Alok; LeClair, Andre; Hartwig, Jason

2017-01-01

This paper describes a mathematical formulation and numerical solution of boiling in a heated tube. The mathematical formulation involves a discretization of the tube into a flow network consisting of fluid nodes and branches and a thermal network consisting of solid nodes and conductors. In the fluid network, the mass, momentum and energy conservation equations are solved and in the thermal network, the energy conservation equation of solids is solved. A pressure-based, finite-volume formulation has been used to solve the equations in the fluid network. The system of equations is solved by a hybrid numerical scheme which solves the mass and momentum conservation equations by a simultaneous Newton-Raphson method and the energy conservation equation by a successive substitution method. The fluid network and thermal network are coupled through heat transfer between the solid and fluid nodes which is computed by Chen's correlation of saturated boiling heat transfer. The computer model is developed using the Generalized Fluid System Simulation Program and the numerical predictions are compared with test data.

Process metallurgy simulation for metal drawing process optimization by using two-scale finite element method

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

Nakamachi, Eiji; Yoshida, Takashi; Yamaguchi, Toshihiko

2014-10-06

We developed two-scale FE analysis procedure based on the crystallographic homogenization method by considering the hierarchical structure of poly-crystal aluminium alloy metal. It can be characterized as the combination of two-scale structure, such as the microscopic polycrystal structure and the macroscopic elastic plastic continuum. Micro polycrystal structure can be modeled as a three dimensional representative volume element (RVE). RVE is featured as by 3×3×3 eight-nodes solid finite elements, which has 216 crystal orientations. This FE analysis code can predict the deformation, strain and stress evolutions in the wire drawing processes in the macro- scales, and further the crystal texture andmore » hardening evolutions in the micro-scale. In this study, we analyzed the texture evolution in the wire drawing processes by our two-scale FE analysis code under conditions of various drawing angles of dice. We evaluates the texture evolution in the surface and center regions of the wire cross section, and to clarify the effects of processing conditions on the texture evolution.« less

Process metallurgy simulation for metal drawing process optimization by using two-scale finite element method

NASA Astrophysics Data System (ADS)

Nakamachi, Eiji; Yoshida, Takashi; Kuramae, Hiroyuki; Morimoto, Hideo; Yamaguchi, Toshihiko; Morita, Yusuke

2014-10-01

We developed two-scale FE analysis procedure based on the crystallographic homogenization method by considering the hierarchical structure of poly-crystal aluminium alloy metal. It can be characterized as the combination of two-scale structure, such as the microscopic polycrystal structure and the macroscopic elastic plastic continuum. Micro polycrystal structure can be modeled as a three dimensional representative volume element (RVE). RVE is featured as by 3×3×3 eight-nodes solid finite elements, which has 216 crystal orientations. This FE analysis code can predict the deformation, strain and stress evolutions in the wire drawing processes in the macro- scales, and further the crystal texture and hardening evolutions in the micro-scale. In this study, we analyzed the texture evolution in the wire drawing processes by our two-scale FE analysis code under conditions of various drawing angles of dice. We evaluates the texture evolution in the surface and center regions of the wire cross section, and to clarify the effects of processing conditions on the texture evolution.

Electro-mechanical analysis of composite and sandwich multilayered structures by shell elements with node-dependent kinematics

NASA Astrophysics Data System (ADS)

Carrera; Valvano; Kulikov

2018-01-01

In this work, a new class of finite elements for the analysis of composite and sandwich shells embedding piezoelectric skins and patches is proposed. The main idea of models coupling is developed by presenting the concept of nodal dependent kinematics where the same finite element can present at each node a different approximation of the main unknowns by setting a node-wise through-the-thickness approximation base. In a global/local approach scenario, the computational costs can be reduced drastically by assuming refined theories only in those zones/nodes of the structural domain where the resulting strain and stress states, and their electro-mechanical coupling present a complex distribution. Several numerical investigations are carried out to validate the accuracy and efficiency of the present shell element. An accurate representation of mechanical stresses and electric displacements in localized zones is possible with reduction of the computational costs if an accurate distribution of the higher-order kinematic capabilities is performed. On the contrary, the accuracy of the solution in terms of mechanical displacements and electric potential values depends on the global approximation over the whole structure. The efficacy of the present node-dependent variable kinematic models, thus, depends on the characteristics of the problem under consideration as well as on the required analysis type.

STS-88 Post Flight Presentation

NASA Technical Reports Server (NTRS)

1998-01-01

The flight crew of the STS-88 mission, Commander Robert D. Cabana, Pilot Frederick W. Sturckow, and Mission Specialists Nancy J. Currie, Jerry L. Ross, James H. Newman, and Sergei K. Krikalev, present a video mission over-view of their space flight. Images include prelaunch activities such as eating the traditional breakfast, crew suit-up, and the ride out to the launch pad. Also, included are various panoramic views of the shuttle on the pad. The crew can be seen being readied in the "white room" for their mission. After the closing of the hatch and arm retraction, launch activities are shown including countdown, engine ignition, launch, and the separation of the Solid Rocket Boosters. Once the seven-day mission begins, the astronauts comment on the mating of the U.S.-built Node 1 station element to the Functional Energy Block (FGB) which was already in orbit, and two EVAs that were planned to connect power and data transmission cables between the Node and the FGB. The crew can also be seen conducting a series of rendezvous maneuvers similar to those conducted on other Shuttle missions to reach the orbiting FGB.

Reversible non-volatile switch based on a TCNQ charge transfer complex

NASA Technical Reports Server (NTRS)

DiStefano, Salvador (Inventor); Moacanin, Jovan (Inventor); Nagasubramanian, Ganesan (Inventor)

1993-01-01

A solid-state synaptic memory matrix (10) having switchable weakly conductive connections at each node (24) whose resistances can be selectably increased or decreased over several orders of magnitude by control signals of opposite polarity, and which will remain stable after the signals are removed, comprises an insulated substrate (16), a set of electrical conductors (14) upon which is deposited a layer (18) of an organic conducting polymer, which changes from an insulator to a conductor upon the transfer of electrons, such as polymerized pyrrole doped with 7,7,8,8-tetracyanoquinodimethane (TCNQ), covered by a second set of conductors (20) laid at right angles to the first.

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra (second from right) talks with workers in the Space Station Processing Facility about the Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. . The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

NASA Image and Video Library

2004-02-03

KENNEDY SPACE CENTER, FLA. - Astronaut Tim Kopra (second from right) talks with workers in the Space Station Processing Facility about the Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. . The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

LayTracks3D: A new approach for meshing general solids using medial axis transform

DOE PAGES

Quadros, William Roshan

2015-08-22

This study presents an extension of the all-quad meshing algorithm called LayTracks to generate high quality hex-dominant meshes of general solids. LayTracks3D uses the mapping between the Medial Axis (MA) and the boundary of the 3D domain to decompose complex 3D domains into simpler domains called Tracks. Tracks in 3D have no branches and are symmetric, non-intersecting, orthogonal to the boundary, and the shortest path from the MA to the boundary. These properties of tracks result in desired meshes with near cube shape elements at the boundary, structured mesh along the boundary normal with any irregular nodes restricted to themore » MA, and sharp boundary feature preservation. The algorithm has been tested on a few industrial CAD models and hex-dominant meshes are shown in the Results section. Work is underway to extend LayTracks3D to generate all-hex meshes.« less

Quadrilateral finite element mesh coarsening

DOEpatents

Staten, Matthew L; Dewey, Mark W; Benzley, Steven E

2012-10-16

Techniques for coarsening a quadrilateral mesh are described. These techniques include identifying a coarsening region within the quadrilateral mesh to be coarsened. Quadrilateral elements along a path through the coarsening region are removed. Node pairs along opposite sides of the path are identified. The node pairs along the path are then merged to collapse the path.

Towards the stabilization of the low density elements in topology optimization with large deformation

NASA Astrophysics Data System (ADS)

Lahuerta, Ricardo Doll; Simões, Eduardo T.; Campello, Eduardo M. B.; Pimenta, Paulo M.; Silva, Emilio C. N.

2013-10-01

This work addresses the treatment of lower density regions of structures undergoing large deformations during the design process by the topology optimization method (TOM) based on the finite element method. During the design process the nonlinear elastic behavior of the structure is based on exact kinematics. The material model applied in the TOM is based on the solid isotropic microstructure with penalization approach. No void elements are deleted and all internal forces of the nodes surrounding the void elements are considered during the nonlinear equilibrium solution. The distribution of design variables is solved through the method of moving asymptotes, in which the sensitivity of the objective function is obtained directly. In addition, a continuation function and a nonlinear projection function are invoked to obtain a checkerboard free and mesh independent design. 2D examples with both plane strain and plane stress conditions hypothesis are presented and compared. The problem of instability is overcome by adopting a polyconvex constitutive model in conjunction with a suggested relaxation function to stabilize the excessive distorted elements. The exact tangent stiffness matrix is used. The optimal topology results are compared to the results obtained by using the classical Saint Venant-Kirchhoff constitutive law, and strong differences are found.

Development of technology for modeling of a 1/8-scale dynamic model of the shuttle Solid Rocket Booster (SRB)

NASA Technical Reports Server (NTRS)

Levy, A.; Zalesak, J.; Bernstein, M.; Mason, P. W.

1974-01-01

A NASTRAN analysis of the solid rocket booster (SRB) substructure of the space shuttle 1/8-scale structural dynamics model. The NASTRAN finite element modeling capability was first used to formulate a model of a cylinder 10 in. radius by a 200 in. length to investigate the accuracy and adequacy of the proposed grid point spacing. Results were compared with a shell analysis and demonstrated relatively accurate results for NASTRAN for the lower modes, which were of primary interest. A finite element model of the full SRB was then formed using CQUAD2 plate elements containing membrane and bending stiffness and CBAR offset bar elements to represent the longerons and frames. Three layers of three-dimensional CHEXAI elements were used to model the propellant. This model, consisting of 4000 degrees of freedom (DOF) initially, was reduced to 176 DOF using Guyan reduction. The model was then submitted for complex Eigenvalue analysis. After experiencing considerable difficulty with attempts to run the complete model, it was split into two substructres. These were run separately and combined into a single 116 degree of freedom A set which was successfully run. Results are reported.

KENNEDY SPACE CENTER, FLA. - Various elements intended for the International Space Station are lined up in the Space Station Processing Facility. The newest to arrive at KSC are in the rear: at left, the U.S. Node 2, and at right, the Japanese Experiment Module (JEM). The two elements are undergoing a Multi-Element Integrated Test (MEIT). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Developed by the National Space Development Agency of Japan (NASDA), the JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

NASA Image and Video Library

2003-08-27

KENNEDY SPACE CENTER, FLA. - Various elements intended for the International Space Station are lined up in the Space Station Processing Facility. The newest to arrive at KSC are in the rear: at left, the U.S. Node 2, and at right, the Japanese Experiment Module (JEM). The two elements are undergoing a Multi-Element Integrated Test (MEIT). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Developed by the National Space Development Agency of Japan (NASDA), the JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

KENNEDY SPACE CENTER, FLA. - Various elements intended for the International Space Station are lined up in the Space Station Processing Facility. The newest to arrive at KSC are in the rear: at left, the U.S. Node 2, and next to it at right, the Japanese Experiment Module (JEM). The two elements are undergoing a Multi-Element Integrated Test (MEIT). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Developed by the National Space Development Agency of Japan (NASDA), the JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

NASA Image and Video Library

2003-09-03

KENNEDY SPACE CENTER, FLA. - Various elements intended for the International Space Station are lined up in the Space Station Processing Facility. The newest to arrive at KSC are in the rear: at left, the U.S. Node 2, and next to it at right, the Japanese Experiment Module (JEM). The two elements are undergoing a Multi-Element Integrated Test (MEIT). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Developed by the National Space Development Agency of Japan (NASDA), the JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

Boeing technicians discuss mating PMA-2 to Node 1 in the SSPF as STS-88 launch preparations continue

NASA Technical Reports Server (NTRS)

1998-01-01

Boeing technicians discuss mating Pressurized Mating Adapter (PMA)-2 to Node 1 of the International Space Station (ISS) in KSC's Space Station Processing Facility (SSPF). The node is the first element of the ISS to be manufactured in the United States and is currently scheduled to lift off aboard the Space Shuttle Endeavour on STS-88 later this year, along with PMAs 1 and 2. This PMA is a cone-shaped connector to Node 1, which will have two PMAs attached once this mate is completed. Once in space, Node 1 will function as a connecting passageway to the living and working areas of the ISS. It has six hatches that will serve as docking ports to the U.S. laboratory module, U.S. habitation module, an airlock and other space station elements.

Explicit formulation of an anisotropic Allman/DKT 3-node thin triangular flat shell elements

NASA Astrophysics Data System (ADS)

Ertas, A.; Krafcik, J. T.; Ekwaro-Osire, S.

A simple, explicit formulation of the stiffness matrix for an anisotropic, 3-node, thin triangular, flat shell element in global coordinates is presented. An Allman triangle is used for membrane stiffness. The membrane stiffness matrix is explicitly derived by applying an Allman transformation to a Felippa 6-node linear strain triangle (LST). Bending stiffness is incorporated by the use of a discrete Kirchhoff triangle (DKT) bending triangle. Stiffness terms resulting from anisotropic membrane-bending coupling are included by integrating, in area coordinates, membrane and bending strain-displacement matrices.

Method and apparatus for connecting finite element meshes and performing simulations therewith

DOEpatents

Dohrmann, Clark R.; Key, Samuel W.; Heinstein, Martin W.

2003-05-06

The present invention provides a method of connecting dissimilar finite element meshes. A first mesh, designated the master mesh, and a second mesh, designated the slave mesh, each have interface surfaces proximal the other. Each interface surface has a corresponding interface mesh comprising a plurality of interface nodes. Each slave interface node is assigned new coordinates locating the interface node on the interface surface of the master mesh. The slave interface surface is further redefined to be the projection of the slave interface mesh onto the master interface surface.

Coupled structural/thermal/electromagnetic analysis/tailoring of graded composite structures

NASA Technical Reports Server (NTRS)

Mcknight, R. L.; Chen, P. C.; Dame, L. T.; Huang, H.

1992-01-01

Accomplishments are described for the first year effort of a 5-year program to develop a methodology for coupled structural/thermal/electromagnetic analysis/tailoring of graded composite structures. These accomplishments include: (1) the results of the selective literature survey; (2) 8-, 16-, and 20-noded isoparametric plate and shell elements; (3) large deformation structural analysis; (4) eigenanalysis; (5) anisotropic heat transfer analysis; and (6) anisotropic electromagnetic analysis.

Synthetic Poly(L-Glutamic Acid)-conjugated CpG Exhibits Antitumor Efficacy With Increased Retention in Tumor and Draining Lymph Nodes After Intratumoral Injection in a Mouse Model of Melanoma.

PubMed

Ma, Qing; Zhou, Dapeng; DeLyria, Elizabeth S; Wen, Xiaoxia; Lu, Wei; Thapa, Prakash; Liu, Chengwen; Li, Dan; Bassett, Roland L; Overwijk, Willem W; Hwu, Patrick; Li, Chun

2017-01-01

There is an urgent need for new clinically applicable drug-delivery methods to enhance accumulation of immune-activating drugs in tumors. We synthesized a poly(L-glutamic acid)-CpG ODN2216 conjugate (PG-CpG) and injected it intratumorally into C57BL/6 mice bearing subcutaneous B16-ovalbumin melanoma. PG-CpG elicited the same potent antitumoral activity as CpG with respect to reducing tumor growth and triggering antigen-specific CD8 T-cell responses in this well-established solid tumor model. Moreover, PG-CpG was retained significantly longer in both tumor and draining lymph nodes than was free CpG after intratumoral injection. Specifically, 48 hours after injection, 26.5%±16.9% of the injected PG-CpG dose versus 4.72%±2.61% of free CpG remained at the tumor, and 1.53%±1.22% of the injected PG-CpG versus 0.37%±0.33% of free CpG was retained in the draining inguinal lymph nodes. These findings indicate that PG is an effective synthetic polymeric carrier for delivery of immunostimulatory agents to tumors and lymph nodes.

Vibration characteristics of 1/8-scale dynamic models of the space-shuttle solid-rocket boosters

NASA Technical Reports Server (NTRS)

Leadbetter, S. A.; Stephens, W.; Sewall, J. L.; Majka, J. W.; Barret, J. R.

1976-01-01

Vibration tests and analyses of six 1/8 scale models of the space shuttle solid rocket boosters are reported. Natural vibration frequencies and mode shapes were obtained for these aluminum shell models having internal solid fuel configurations corresponding to launch, midburn (maximum dynamic pressure), and near endburn (burnout) flight conditions. Test results for longitudinal, torsional, bending, and shell vibration frequencies are compared with analytical predictions derived from thin shell theory and from finite element plate and beam theory. The lowest analytical longitudinal, torsional, bending, and shell vibration frequencies were within + or - 10 percent of experimental values. The effects of damping and asymmetric end skirts on natural vibration frequency were also considered. The analytical frequencies of an idealized full scale space shuttle solid rocket boosted structure are computed with and without internal pressure and are compared with the 1/8 scale model results.

An automatic granular structure generation and finite element analysis of heterogeneous semi-solid materials

NASA Astrophysics Data System (ADS)

Sharifi, Hamid; Larouche, Daniel

2015-09-01

The quality of cast metal products depends on the capacity of the semi-solid metal to sustain the stresses generated during the casting. Predicting the evolution of these stresses with accuracy in the solidification interval should be highly helpful to avoid the formation of defects like hot tearing. This task is however very difficult because of the heterogeneous nature of the material. In this paper, we propose to evaluate the mechanical behaviour of a metal during solidification using a mesh generation technique of the heterogeneous semi-solid material for a finite element analysis at the microscopic level. This task is done on a two-dimensional (2D) domain in which the granular structure of the solid phase is generated surrounded by an intergranular and interdendritc liquid phase. Some basic solid grains are first constructed and projected in the 2D domain with random orientations and scale factors. Depending on their orientation, the basic grains are combined to produce larger grains or separated by a liquid film. Different basic grain shapes can produce different granular structures of the mushy zone. As a result, using this automatic grain generation procedure, we can investigate the effect of grain shapes and sizes on the thermo-mechanical behaviour of the semi-solid material. The granular models are automatically converted to the finite element meshes. The solid grains and the liquid phase are meshed properly using quadrilateral elements. This method has been used to simulate the microstructure of a binary aluminium-copper alloy (Al-5.8 wt% Cu) when the fraction solid is 0.92. Using the finite element method and the Mie-Grüneisen equation of state for the liquid phase, the transient mechanical behaviour of the mushy zone under tensile loading has been investigated. The stress distribution and the bridges, which are formed during the tensile loading, have been detected.

Effecting a broadcast with an allreduce operation on a parallel computer

DOEpatents

Almasi, Gheorghe; Archer, Charles J.; Ratterman, Joseph D.; Smith, Brian E.

2010-11-02

A parallel computer comprises a plurality of compute nodes organized into at least one operational group for collective parallel operations. Each compute node is assigned a unique rank and is coupled for data communications through a global combining network. One compute node is assigned to be a logical root. A send buffer and a receive buffer is configured. Each element of a contribution of the logical root in the send buffer is contributed. One or more zeros corresponding to a size of the element are injected. An allreduce operation with a bitwise OR using the element and the injected zeros is performed. And the result for the allreduce operation is determined and stored in each receive buffer.

A Novel Polygonal Finite Element Method: Virtual Node Method

NASA Astrophysics Data System (ADS)

Tang, X. H.; Zheng, C.; Zhang, J. H.

2010-05-01

Polygonal finite element method (PFEM), which can construct shape functions on polygonal elements, provides greater flexibility in mesh generation. However, the non-polynomial form of traditional PFEM, such as Wachspress method and Mean Value method, leads to inexact numerical integration. Since the integration technique for non-polynomial functions is immature. To overcome this shortcoming, a great number of integration points have to be used to obtain sufficiently exact results, which increases computational cost. In this paper, a novel polygonal finite element method is proposed and called as virtual node method (VNM). The features of present method can be list as: (1) It is a PFEM with polynomial form. Thereby, Hammer integral and Gauss integral can be naturally used to obtain exact numerical integration; (2) Shape functions of VNM satisfy all the requirements of finite element method. To test the performance of VNM, intensive numerical tests are carried out. It found that, in standard patch test, VNM can achieve significantly better results than Wachspress method and Mean Value method. Moreover, it is observed that VNM can achieve better results than triangular 3-node elements in the accuracy test.

KENNEDY SPACE CENTER, FLA. - The U.S. Node 2 is undergoing a Multi-Element Integrated Test (MEIT) in the Space Station Processing Facility. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

NASA Image and Video Library

2003-08-27

KENNEDY SPACE CENTER, FLA. - The U.S. Node 2 is undergoing a Multi-Element Integrated Test (MEIT) in the Space Station Processing Facility. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

Skeletal response to maxillary protraction with and without maxillary expansion: a finite element study.

PubMed

Gautam, Pawan; Valiathan, Ashima; Adhikari, Raviraj

2009-06-01

The purpose of this finite element study was to evaluate biomechanically 2 treatment modalities-maxillary protraction alone and in combination with maxillary expansion-by comparing the displacement of various craniofacial structures. Two 3-dimensional analytical models were developed from sequential computed tomography scan images taken at 2.5-mm intervals of a dry young skull. AutoCAD software (2004 version, Autodesk, San Rafael, Calif) and ANSYS software (version 10, Belcan Engineering Group, Cincinnati, Ohio) were used. The model consisted of 108,799 solid 10 node 92 elements, 193,633 nodes, and 580,899 degrees of freedom. In the first model, maxillary protraction forces were simulated by applying 1 kg of anterior force 30 degrees downward to the palatal plane. In the second model, a 4-mm midpalatal suture opening and maxillary protraction were simulated. Forward displacement of the nasomaxillary complex with upward and forward rotation was observed with maxillary protraction alone. No rotational tendency was noted when protraction was carried out with 4 mm of transverse expansion. A tendency for anterior maxillary constriction after maxillary protraction was evident. The amounts of displacement in the frontal, vertical, and lateral directions with midpalatal suture opening were greater compared with no opening of the midpalatal suture. The forward and downward displacements of the nasomaxillary complex with maxillary protraction and maxillary expansion more closely approximated the natural growth direction of the maxilla. Displacements of craniofacial structures were more favorable for the treatment of skeletal Class III maxillary retrognathia when maxillary protraction was used with maxillary expansion. Hence, biomechanically, maxillary protraction combined with maxillary expansion appears to be a superior treatment modality for the treatment of maxillary retrognathia than maxillary protraction alone.

On the existence and stability conditions for mixed-hybrid finite element solutions based on Reissner's variational principle

NASA Technical Reports Server (NTRS)

Karlovitz, L. A.; Atluri, S. N.; Xue, W.-M.

1985-01-01

The extensions of Reissner's two-field (stress and displacement) principle to the cases wherein the displacement field is discontinuous and/or the stress field results in unreciprocated tractions, at a finite number of surfaces ('interelement boundaries') in a domain (as, for instance, when the domain is discretized into finite elements), is considered. The conditions for the existence, uniqueness, and stability of mixed-hybrid finite element solutions based on such discontinuous fields, are summarized. The reduction of these global conditions to local ('element') level, and the attendant conditions on the ranks of element matrices, are discussed. Two examples of stable, invariant, least-order elements - a four-node square planar element and an eight-node cubic element - are discussed in detail.

Use of edge-based finite elements for solving three dimensional scattering problems

NASA Technical Reports Server (NTRS)

Chatterjee, A.; Jin, J. M.; Volakis, John L.

1991-01-01

Edge based finite elements are free from drawbacks associated with node based vectorial finite elements and are, therefore, ideal for solving 3-D scattering problems. The finite element discretization using edge elements is checked by solving for the resonant frequencies of a closed inhomogeneously filled metallic cavity. Great improvements in accuracy are observed when compared to the classical node based approach with no penalty in terms of computational time and with the expected absence of spurious modes. A performance comparison between the edge based tetrahedra and rectangular brick elements is carried out and tetrahedral elements are found to be more accurate than rectangular bricks for a given storage intensity. A detailed formulation for the scattering problem with various approaches for terminating the finite element mesh is also presented.

Adinkras from ordered quartets of BC4 Coxeter group elements and regarding 1,358,954,496 matrix elements of the Gadget

NASA Astrophysics Data System (ADS)

Gates, S. James; Guyton, Forrest; Harmalkar, Siddhartha; Kessler, David S.; Korotkikh, Vadim; Meszaros, Victor A.

2017-06-01

We examine values of the Adinkra Holoraumy-induced Gadget representation space metric over all possible four-color, four-open node, and four-closed node adinkras. Of the 1,358,954,496 gadget matrix elements, only 226,492,416 are non-vanishing and take on one of three values: -1/3, 1/3, or 1 and thus a subspace isomorphic to a description of a body-centered tetrahedral molecule emerges.

PMA-2 is in the process of being mated to Node 1 in the SSPF as STS-88 launch preparations continue

NASA Technical Reports Server (NTRS)

1998-01-01

Pressurized Mating Adapter (PMA)-2 is in the process of being mated to Node 1 of the International Space Station (ISS) under the supervision of Boeing technicians in KSC's Space Station Processing Facility (SSPF). The node is the first element of the ISS to be manufactured in the United States and is currently scheduled to lift off aboard the Space Shuttle Endeavour on STS- 88 later this year, along with PMAs 1 and 2. This PMA is a cone- shaped connector to Node 1, which will have two PMAs attached once this mate is completed. Once in space, Node 1 will function as a connecting passageway to the living and working areas of the ISS. It has six hatches that will serve as docking ports to the U.S. laboratory module, U.S. habitation module, an airlock and other space station elements.

Anatomic-histologic study of the floor of the mouth: the lingual lymph nodes.

PubMed

Ananian, Sargis G; Gvetadze, Shalva R; Ilkaev, Konstantin D; Mochalnikova, Valeria V; Zayratiants, Georgiy O; Mkhitarov, Vladimir A; Yang, Xin; Ciciashvili, Aleksandr M

2015-06-01

The lingual lymph nodes are inconstant nodes located within the fascial/intermuscular spaces of the floor of the mouth. Oral tongue squamous cell carcinoma has been reported to recur and metastasize in lingual lymph nodes with poor prognosis. Lingual lymph nodes are not currently included in basic tongue squamous cell carcinoma surgery. Twenty-one cadavers (7 males, 14 females) were studied, aged from 57 to 94 years (mean age 76.3 years). The gross specimen of the floor of the mouth was divided into blocks: A (median nodes), B, B' (parahyoid), C, C' (paraglandular). Serial histological microslides were cut and stained with hematoxylin-eosin. Frequency of lingual lymph nodes in each block and their microscopic features were assessed. The lingual lymph nodes in overall number of 7 were detected in 5 of the 21 cadavers (23.8%). The total incidence of lingual lymph node was 33.3% (7 nodes/21 cadavers). Block A failed to demonstrate any lymph nodes (0%); Blocks B, B'-2 nodes (9.5%) and 2 nodes (9.5%), respectively; Blocks C, C'-1 node (4.8%) and 2 nodes (9.5%), respectively. The mean lingual lymph node length was 4.1 mm (from 1.4 to 8.7 mm), the mean thickness was 2.8 mm (from 0.8 to 7.5 mm). Five cadavers (23.8%) revealed mucosa-associated lymphoid tissue. Atrophic changes appeared in 4 (57.1%) lingual lymph nodes. The presence of lymph node-bearing tissue in the floor of the mouth is demonstrated. In account of resection radicalism and better local control the fat tissue of the floor of the mouth should be removed in conjunction to glossectomy. Further anatomic and clinical research is required to establish the role of lingual lymph node in oral squamous cell carcinoma recurrence and metastasis. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Cryogenic solid Schmidt camera as a base for future wide-field IR systems

NASA Astrophysics Data System (ADS)

Yudin, Alexey N.

2011-11-01

Work is focused on study of capability of solid Schmidt camera to serve as a wide-field infrared lens for aircraft system with whole sphere coverage, working in 8-14 um spectral range, coupled with spherical focal array of megapixel class. Designs of 16 mm f/0.2 lens with 60 and 90 degrees sensor diagonal are presented, their image quality is compared with conventional solid design. Achromatic design with significantly improved performance, containing enclosed soft correcting lens behind protective front lens is proposed. One of the main goals of the work is to estimate benefits from curved detector arrays in 8-14 um spectral range wide-field systems. Coupling of photodetector with solid Schmidt camera by means of frustrated total internal reflection is considered, with corresponding tolerance analysis. The whole lens, except front element, is considered to be cryogenic, with solid Schmidt unit to be flown by hydrogen for improvement of bulk transmission.

Fixed-node quantum Monte Carlo

NASA Astrophysics Data System (ADS)

Anderson, James B.

Quantum Monte Carlo methods cannot at present provide exact solutions of the Schrödinger equation for systems with more than a few electrons. But, quantum Monte Carlo calculations can provide very low energy, highly accurate solutions for many systems ranging up to several hundred electrons. These systems include atoms such as Be and Fe, molecules such as H2O, CH4, and HF, and condensed materials such as solid N2 and solid silicon. The quantum Monte Carlo predictions of their energies and structures may not be `exact', but they are the best available. Most of the Monte Carlo calculations for these systems have been carried out using approximately correct fixed nodal hypersurfaces and they have come to be known as `fixed-node quantum Monte Carlo' calculations. In this paper we review these `fixed node' calculations and the accuracies they yield.

Construction of optimal 3-node plate bending triangles by templates

NASA Astrophysics Data System (ADS)

Felippa, C. A.; Militello, C.

A finite element template is a parametrized algebraic form that reduces to specific finite elements by setting numerical values to the free parameters. The present study concerns Kirchhoff Plate-Bending Triangles (KPT) with 3 nodes and 9 degrees of freedom. A 37-parameter template is constructed using the Assumed Natural Deviatoric Strain (ANDES). Specialization of this template includes well known elements such as DKT and HCT. The question addressed here is: can these parameters be selected to produce high performance elements? The study is carried out by staged application of constraints on the free parameters. The first stage produces element families satisfying invariance and aspect ratio insensitivity conditions. Application of energy balance constraints produces specific elements. The performance of such elements in benchmark tests is presently under study.

Revisiting the elemental composition and the calorific value of the organic fraction of municipal solid wastes.

PubMed

Komilis, Dimitrios; Evangelou, Alexandros; Giannakis, Georgios; Lymperis, Constantinos

2012-03-01

In this work, the elemental content (C, N, H, S, O), the organic matter content and the calorific value of various organic components that are commonly found in the municipal solid waste stream were measured. The objective of this work was to develop an empirical equation to describe the calorific value of the organic fraction of municipal solid waste as a function of its elemental composition. The MSW components were grouped into paper wastes, food wastes, yard wastes and plastics. Sample sizes ranged from 0.2 to 0.5 kg. In addition to the above individual components, commingled municipal solid wastes were sampled from a bio-drying facility located in Crete (sample sizes ranged from 8 to 15 kg) and were analyzed for the same parameters. Based on the results of this work, an improved empirical model was developed that revealed that carbon, hydrogen and oxygen were the only statistically significant predictors of calorific value. Total organic carbon was statistically similar to total carbon for most materials in this work. The carbon to organic matter ratio of 26 municipal solid waste substrates and of 18 organic composts varied from 0.40 to 0.99. An approximate chemical empirical formula calculated for the organic fraction of commingled municipal solid wastes was C(32)NH(55)O(16). Copyright © 2011 Elsevier Ltd. All rights reserved.

Sheep lymph-nodes as a biological indicator of environmental exposure to fluoro-edenite

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

Ledda, Caterina, E-mail: cledda@unict.it; Hygiene and Public Health, Department of Medical Sciences, Surgical and Advanced Technologies “GF Ingrassia”, University of Catania, Catania; Loreto, Carla

A significantly increased incidence of pleural mesothelioma in Biancavilla (Sicily, Italy) has been attributed to exposure to fluoro-edenite (FE), a fibrous amphibole extracted from a local stone quarry. The lymph-nodes draining the pulmonary lobes of sheep grazing around the town were examined, to gain insights into fibre diffusion. The pasture areas of six sheep flocks lying about 3 km from Biancavilla were located using the global positioning system. The cranial tracheobronchial and one middle mediastinal lymph-node as well as four lung tissue samples were collected from 10 animals from each flock and from 10 control sheep for light and scanningmore » electron microscopy (SEM) examination. The lymph-nodes from exposed sheep were enlarged and exhibited signs of anthracosis. Histologically, especially at the paracortical level, they showed lymph-follicle hyperplasia with large reactive cores and several macrophages (coniophages) containing grey-brownish particulate interspersed with elements with a fibril structure, forming aggregates of varying dimensions (coniophage nodules). Similar findings were detected in some peribronchiolar areas of the lung parenchyma. SEM examination showed that FE fibres measured 8–41 µm in length and 0.4–1.39 µm in diameter in both lymph-nodes and lung tissue. Monitoring of FE fibres in sheep lymph-nodes using appropriate techniques can help set up environmental pollution surveillance. - Highlights: • Lymph-nodes draining sheep lung were used to assess environmental fluoro-edenite exposure. • Monitoring fluoro-edenite fibres in sheep lung nodes can provide pollution surveillance. • Our findings document a risk of fluoro-edenite fibre inhalation a few kilometres from the source. • Sheep appear to be a valuable bioindicator species.« less

KENNEDY SPACE CENTER, FLA. - An overview of the Space Station Processing Facility shows workstands and ISS elements. The most recent additions are the Japanese Experiment Module (JEM)’s pressurized module and the Italian-built Node 2. The pressurized module is the first element of the JEM, Japan’s primary contribution to the Space Station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. Node 2 will be installed on the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

NASA Image and Video Library

2003-06-06

KENNEDY SPACE CENTER, FLA. - An overview of the Space Station Processing Facility shows workstands and ISS elements. The most recent additions are the Japanese Experiment Module (JEM)’s pressurized module and the Italian-built Node 2. The pressurized module is the first element of the JEM, Japan’s primary contribution to the Space Station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. Node 2 will be installed on the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

KENNEDY SPACE CENTER, FLA. - A view of the Space Station Processing Facility shows workstands and ISS elements. The most recent additions are the Japanese Experiment Module (JEM)’s pressurized module and the Italian-built Node 2. The pressurized module is the first element of the JEM, Japan’s primary contribution to the Space Station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. Node 2 will be installed on the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

NASA Image and Video Library

2003-06-06

KENNEDY SPACE CENTER, FLA. - A view of the Space Station Processing Facility shows workstands and ISS elements. The most recent additions are the Japanese Experiment Module (JEM)’s pressurized module and the Italian-built Node 2. The pressurized module is the first element of the JEM, Japan’s primary contribution to the Space Station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. Node 2 will be installed on the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

Using Object-Oriented Databases for Implementation of Interactive Electronic Technical Manuals

DTIC Science & Technology

1992-03-01

analytical process applied throughout the system acquisition program in order to define supportability related design factors and to ensure development of a...Node Alternatives Node Alternatives (NODEALTS) is a list of mutually exclusive nodes, grouped together by the fact that they apply to different...contextual situations. The content specific layer NODEALTS element is a reference to a set of nodes that might apply in different situations. No hierarchy

Free vibration Analysis of Sandwich Plates with cutout

NASA Astrophysics Data System (ADS)

Mishra, N.; Basa, B.; Sarangi, S. K.

2016-09-01

This paper presents the free vibration analysis of sandwich plates with cutouts. Cutouts are inevitable in structural applications and the presence of these cutouts in the structures greatly influences their dynamic characteristics. A finite element model has been developed here using the ANSYS 15.0 software to study the free vibration characteristics of sandwich plates in the presence of cutouts. Shell 281 element, an 8-noded element with six degrees of freedom suited for analyzing thin to moderately thick structures is considered in the development of the model. Block Lanczose method is adopted to extract the mode shapes to obtain the natural frequency corresponding to free vibration of the plate. The effects of parametric variation on the natural frequency of the sandwich plates with cutout are studied and results are presented.

Three-dimensional finite element modeling of a maxillary premolar tooth based on the micro-CT scanning: a detailed description.

PubMed

Huang, Zheng; Chen, Zhi

2013-10-01

This study describes the details of how to construct a three-dimensional (3D) finite element model of a maxillary first premolar tooth based on micro-CT data acquisition technique, MIMICS software and ANSYS software. The tooth was scanned by micro-CT, in which 1295 slices were obtained and then 648 slices were selected for modeling. The 3D surface mesh models of enamel and dentin were created by MIMICS (STL file). The solid mesh model was constructed by ANSYS. After the material properties and boundary conditions were set, a loading analysis was performed to demonstrate the applicableness of the resulting model. The first and third principal stresses were then evaluated. The results showed that the number of nodes and elements of the finite element model were 56 618 and 311801, respectively. The geometric form of the model was highly consistent with that of the true tooth, and the deviation between them was -0.28%. The loading analysis revealed the typical stress patterns in the contour map. The maximum compressive stress existed in the contact points and the maximum tensile stress existed in the deep fissure between the two cusps. It is concluded that by using the micro-CT and highly integrated software, construction of the 3D finite element model with high quality will not be difficult for clinical researchers.

An adaptively refined XFEM with virtual node polygonal elements for dynamic crack problems

NASA Astrophysics Data System (ADS)

Teng, Z. H.; Sun, F.; Wu, S. C.; Zhang, Z. B.; Chen, T.; Liao, D. M.

2018-02-01

By introducing the shape functions of virtual node polygonal (VP) elements into the standard extended finite element method (XFEM), a conforming elemental mesh can be created for the cracking process. Moreover, an adaptively refined meshing with the quadtree structure only at a growing crack tip is proposed without inserting hanging nodes into the transition region. A novel dynamic crack growth method termed as VP-XFEM is thus formulated in the framework of fracture mechanics. To verify the newly proposed VP-XFEM, both quasi-static and dynamic cracked problems are investigated in terms of computational accuracy, convergence, and efficiency. The research results show that the present VP-XFEM can achieve good agreement in stress intensity factor and crack growth path with the exact solutions or experiments. Furthermore, better accuracy, convergence, and efficiency of different models can be acquired, in contrast to standard XFEM and mesh-free methods. Therefore, VP-XFEM provides a suitable alternative to XFEM for engineering applications.

New strategies for SHM based on a multichannel wireless AE node

NASA Astrophysics Data System (ADS)

Godinez-Azcuaga, Valery; Ley, Obdulia

2014-03-01

This paper discusses the development of an Acoustic Emission (AE) wireless node and its application for SHM (Structural Health Monitoring). The instrument development was planned for applications monitoring steel and concrete bridges components. The final product, now commercially available, is a sensor node which includes multiple sensing elements, on board signal processing and analysis capabilities, signal conditioning electronics, power management circuits, wireless data transmission element and energy harvesting unit. The sensing elements are capable of functioning in both passive and active modes, while the multiple parametric inputs are available for connecting various sensor types to measure external characteristics affecting the performance of the structure under monitoring. The output of all these sensors are combined and analyzed at the node in order to minimize the data transmission rate, which consumes significant amount of power. Power management circuits are used to reduce the data collection intervals through selective data acquisition strategies and minimize the sensor node power consumption. This instrument, known as the 1284, is an excellent platform to deploy SHM in the original bridge applications, but initial prototypes has shown significant potential in monitoring composite wind turbine blades and composites mockups of Unmanned Autonomous Vehicles (UAV) components; currently we are working to extend the use of this system to fields such as coal flow, power transformer, and off-shore platform monitoring.

Simulation of fluidized bed coal combustors

NASA Technical Reports Server (NTRS)

Rajan, R.

1979-01-01

The many deficiencies of previous work on simulation of fluidized bed combustion (FBC) processes are presented. An attempt is made to reduce these deficiencies, and to formulate a comprehensive FBC model taking into account the following elements: (1) devolatilization of coal and the subsequent combustion of volatiles and residual char; (2) sulfur dioxide capture by limestone; (3) NOx release and reduction of NOx by char; (4) attrition and elutriation of char and limestone; (5) bubble hydrodynamics; (6) solids mixing; (7) heat transfer between gas and solid, and solid and heat exchange surfaces; and (8) freeboard reactions.

Solid papillary carcinoma of the breast: A special entity needs to be distinguished from conventional invasive carcinoma avoiding over-treatment.

PubMed

Guo, Shuangping; Wang, Yingmei; Rohr, Joseph; Fan, Chaoliang; Li, Qinglong; Li, Xia; Wang, Zhe

2016-04-01

Solid papillary carcinoma of the breast, a newly-defined entity, is poorly recognized, and its nature and management is still debated. Eleven cases of pure solid papillary breast carcinoma in our archive and 253 cases reported in previous literature were retrospectively analyzed for their clinicopathological features and outcomes. The eleven cases occurred in elderly females. Grossly, all tumors were well-circumscribed and typically composed of solid papillary nodules. The tumor cells were bland-looking with low-grade atypia and mitoses < 5/10HPF. Immunophenotypically, all eleven cases showed positivity for ER and PR, negativity for CK5/6 and HER2, and a low proliferative index of Ki67. Five cases showed scattered positivity for myoepithelial marker p63, and four cases were positive for CK5/6 and CD10 around the nodules, whereas the other cases were completely negative for all myoepithelial markers. Five cases expressed the neuroendocrine marker synaptophysin, and six cases expressed chromogranin. In nine cases, mastectomy and axillary lymph nodes excision were performed, and only one showed micrometastasis in an axillary lymph node. There was no local recurrence or distant metastasis or breast carcinoma related-death during the follow-up periods of 50 months. Out of 253 solid papillary breast carcinomas reported in literature, the percentage of axillary lymph node metastasis was 4/136 (3%), with rare local recurrences and distant metastasis; only three patients died of breast carcinoma. Solid papillary carcinoma of the breast is a rare entity with distinctive clinicopathological features and excellent prognosis and should be distinguished from conventional breast carcinoma to avoid over-treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Three dimensional modelling of earthquake rupture cycles on frictional faults

NASA Astrophysics Data System (ADS)

Simpson, Guy; May, Dave

2017-04-01

We are developing an efficient MPI-parallel numerical method to simulate earthquake sequences on preexisting faults embedding within a three dimensional viscoelastic half-space. We solve the velocity form of the elasto(visco)dynamic equations using a continuous Galerkin Finite Element Method on an unstructured pentahedral mesh, which thus permits local spatial refinement in the vicinity of the fault. Friction sliding is coupled to the viscoelastic solid via rate- and state-dependent friction laws using the split-node technique. Our coupled formulation employs a picard-type non-linear solver with a fully implicit, first order accurate time integrator that utilises an adaptive time step that efficiently evolves the system through multiple seismic cycles. The implementation leverages advanced parallel solvers, preconditioners and linear algebra from the Portable Extensible Toolkit for Scientific Computing (PETSc) library. The model can treat heterogeneous frictional properties and stress states on the fault and surrounding solid as well as non-planar fault geometries. Preliminary tests show that the model successfully reproduces dynamic rupture on a vertical strike-slip fault in a half-space governed by rate-state friction with the ageing law.

KSC-98pc592

NASA Image and Video Library

1998-05-05

Pressurized Mating Adapter (PMA)-2 is in the process of being mated to Node 1 of the International Space Station (ISS) under the supervision of Boeing technicians in KSC's Space Station Processing Facility (SSPF). The node is the first element of the ISS to be manufactured in the United States and is currently scheduled to lift off aboard the Space Shuttle Endeavour on STS-88 later this year, along with PMAs 1 and 2. This PMA is a cone-shaped connector to Node 1, which will have two PMAs attached once this mate is completed. Once in space, Node 1 will function as a connecting passageway to the living and working areas of the ISS. It has six hatches that will serve as docking ports to the U.S. laboratory module, U.S. habitation module, an airlock and other space station elements

STS-88 Crew Interview: Nancy Currie

NASA Technical Reports Server (NTRS)

1998-01-01

Nancy Currie discusses the seven-day mission that will be highlighted by the mating of the U.S.-built Node 1 station element to the Functional Energy Block (FGB) which will already be in orbit, and two spacewalks to connect power and data transmission cables between the Node and the FGB. Node 1 will be the first Space Station hardware delivered by the Space Shuttle. He also disscusses the assembly sequence. The crew will conduct a series of rendezvous maneuvers similar to those conducted on other Shuttle missions to reach the orbiting FGB. Once the two elements are docked, Ross and Newman will conduct two scheduled spacewalks to connect power and data cables between the Node, PMAs and the FGB. The day following the spacewalks, Endeavour will undock from the two components, completing the first Space Station assembly mission.

ISS Node-1 and PMA-1 rotated in KSC's SSPF

NASA Technical Reports Server (NTRS)

1997-01-01

The International Space Station's Node 1 and Pressurized Mating Adapter-1 (PMA-1) are rotated by workers in KSC's Space Station Processing Facility. The node is rotated to provide access to different areas of the flight element for processing. Here, the node is rotated to provide access for the installation of heat pipe radiators and a flight computer. The node is scheduled to launch into space on STS-88, slated for a July 9 liftoff at 1:11 p.m. from KSC's Launch Pad 39B.

Advanced Networking and Distributed Systems Defense Advanced Research Projects Agency

DTIC Science & Technology

1992-06-01

balanced. The averagenumber of raviving nodes in each subcube is 2I (1 - *A node cannot transmit a message to a faulty p),. Each will send a units of...space at the processing elements. After being tal traffic will go to memory module 0 in a 1024-node generated, a packet is discarded if it cannot be

Verification of Advective Bar Elements Implemented in the Aria Thermal Response Code.

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

Mills, Brantley

2016-01-01

A verification effort was undertaken to evaluate the implementation of the new advective bar capability in the Aria thermal response code. Several approaches to the verification process were taken : a mesh refinement study to demonstrate solution convergence in the fluid and the solid, visually examining the mapping of the advective bar element nodes to the surrounding surfaces, and a comparison of solutions produced using the advective bars for simple geometries with solutions from commercial CFD software . The mesh refinement study has shown solution convergence for simple pipe flow in both temperature and velocity . Guidelines were provided tomore » achieve appropriate meshes between the advective bar elements and the surrounding volume. Simulations of pipe flow using advective bars elements in Aria have been compared to simulations using the commercial CFD software ANSYS Fluent (r) and provided comparable solutions in temperature and velocity supporting proper implementation of the new capability. Verification of Advective Bar Elements iv Acknowledgements A special thanks goes to Dean Dobranich for his guidance and expertise through all stages of this effort . His advice and feedback was instrumental to its completion. Thanks also goes to Sam Subia and Tolu Okusanya for helping to plan many of the verification activities performed in this document. Thank you to Sam, Justin Lamb and Victor Brunini for their assistance in resolving issues encountered with running the advective bar element model. Finally, thanks goes to Dean, Sam, and Adam Hetzler for reviewing the document and providing very valuable comments.« less

Nasopharyngeal Carcinoma with Cystic Cervical Metastasis Masquerading as Branchial Cleft Cyst: A Potential Pitfall in Diagnosis and Management.

PubMed

Sai-Guan, Lum; Min-Han, Kong; Kah-Wai, Ngan; Mohamad-Yunus, Mohd-Razif

2017-03-01

Most metastatic lymph nodes from head and neck malignancy are solid. Cystic nodes are found in 33% - 61% of carcinomas arise from Waldeyer's ring, of which only 1.8% - 8% originate are from the nasopharynx. Some cystic cervical metastases were initially presumed to be branchial cleft cyst. This case report aims to highlight the unusual presentation of cystic cervical metastasis secondary to nasopharyngeal carcinoma in a young adult. The histopathology, radiological features and management strategy were discussed. A 36-year-old man presented with a solitary cystic cervical swelling, initially diagnosed as branchial cleft cyst. Fine needle aspiration yielded 18 ml of straw-coloured fluid. During cytological examination no atypical cells were observed. Computed tomography of the neck showed a heterogeneous mass with multiseptation medial to the sternocleidomastoid muscle. Histopathological examination of the mass, post excision, revealed a metastatic lymph node. A suspicious mucosal lesion at the nasopharynx was detected after repeated thorough head and neck examinations and the biopsy result confirmed undifferentiated nasopharyngeal carcinoma. Cystic cervical metastasis may occur in young patients under 40 years. The primary tumour may not be obvious during initial presentation because it mimicks benign branchial cleft cyst clinically. Retrospective review of the computed tomography images revealed features that were not characteristic of simple branchial cleft cyst. The inadequacy of assessment and interpretation had lead to the error in diagnosis and subsequent management. Metastatic head and neck lesion must be considered in a young adult with a cystic neck mass.

Sequoia Messaging Rate Benchmark

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

Friedley, Andrew

2008-01-22

The purpose of this benchmark is to measure the maximal message rate of a single compute node. The first num_cores ranks are expected to reside on the 'core' compute node for which message rate is being tested. After that, the next num_nbors ranks are neighbors for the first core rank, the next set of num_nbors ranks are neighbors for the second core rank, and so on. For example, testing an 8-core node (num_cores = 8) with 4 neighbors (num_nbors = 4) requires 8 + 8 * 4 - 40 ranks. The first 8 of those 40 ranks are expected tomore » be on the 'core' node being benchmarked, while the rest of the ranks are on separate nodes.« less

Effects of Solid Solution Strengthening Elements Mo, Re, Ru, and W on Transition Temperatures in Nickel-Based Superalloys with High γ'-Volume Fraction: Comparison of Experiment and CALPHAD Calculations

NASA Astrophysics Data System (ADS)

Ritter, Nils C.; Sowa, Roman; Schauer, Jan C.; Gruber, Daniel; Goehler, Thomas; Rettig, Ralf; Povoden-Karadeniz, Erwin; Koerner, Carolin; Singer, Robert F.

2018-06-01

We prepared 41 different superalloy compositions by an arc melting, casting, and heat treatment process. Alloy solid solution strengthening elements were added in graded amounts, and we measured the solidus, liquidus, and γ'-solvus temperatures of the samples by DSC. The γ'-phase fraction increased as the W, Mo, and Re contents were increased, and W showed the most pronounced effect. Ru decreased the γ'-phase fraction. Melting temperatures (i.e., solidus and liquidus) were increased by addition of Re, W, and Ru (the effect increased in that order). Addition of Mo decreased the melting temperature. W was effective as a strengthening element because it acted as a solid solution strengthener and increased the fraction of fine γ'-precipitates, thus improving precipitation strengthening. Experimentally determined values were compared with calculated values based on the CALPHAD software tools Thermo-Calc (databases: TTNI8 and TCNI6) and MatCalc (database ME-NI). The ME-NI database, which was specially adapted to the present investigation, showed good agreement. TTNI8 also showed good results. The TCNI6 database is suitable for computational design of complex nickel-based superalloys. However, a large deviation remained between the experiment results and calculations based on this database. It also erroneously predicted γ'-phase separations and failed to describe the Ru-effect on transition temperatures.

Boeing technicians join Node 1 for ISS to PMA-1 in the SSPF

NASA Technical Reports Server (NTRS)

1997-01-01

Boeing technicians join Node 1 for the International Space Station (ISS) with the Pressurized Mating Adapter (PMA)-1 in KSC's Space Station Processing Facility. This PMA, identifiable by its bright red ring, is a cone-shaped connector for the space station's structural building block, known as Node 1. Seen here surrounded by scaffolding, Node 1 will have two PMAs attached, the second of which is scheduled for mating to the node in January 1998. The node and PMAs, which will be the first element of the ISS, are scheduled to be launched aboard the Space Shuttle Endeavour on STS-88 in July 1998.

Efficient scalable solid-state neutron detector.

PubMed

Moses, Daniel

2015-06-01

We report on scalable solid-state neutron detector system that is specifically designed to yield high thermal neutron detection sensitivity. The basic detector unit in this system is made of a (6)Li foil coupled to two crystalline silicon diodes. The theoretical intrinsic efficiency of a detector-unit is 23.8% and that of detector element comprising a stack of five detector-units is 60%. Based on the measured performance of this detector-unit, the performance of a detector system comprising a planar array of detector elements, scaled to encompass effective area of 0.43 m(2), is estimated to yield the minimum absolute efficiency required of radiological portal monitors used in homeland security.

The evaluation of shear deformation for contact analysis with large displacement

NASA Astrophysics Data System (ADS)

Nizam, Z. M.; Obiya, H.; Ijima, K.; Azhar, A. T. S.; Hazreek, Z. A. M.; Shaylinda, M. Z. N.

2018-04-01

A common problem encountered in the study of contact problem is the failure to obtain stable and accurate convergence result when the contact node is close to the element edge, which is referred as “critical area”. In previous studies, the modification of the element force equation to apply it to a node-element contact problem using the Euler-Bernoulli beam theory [1]. A simple single-element consists two edges and a contact point was used to simulate contact phenomenon of a plane frame. The modification was proven to be effective by the converge-ability of the unbalanced force at the tip of element edge, which enabled the contact node to “pass-through”, resulting in precise results. However, in another recent study, we discover that, if shear deformation based on Timoshenko beam theory is taken into consideration, a basic simply supported beam coordinate afforded a much simpler and more efficient technique for avoiding the divergence of the unbalanced force in the “critical area”. Using our unique and robust Tangent Stiffness Method, the improved equation can be used to overcome any geometrically nonlinear analyses, including those involving extremely large displacements.

Novel quadrilateral elements based on explicit Hermite polynomials for bending of Kirchhoff-Love plates

NASA Astrophysics Data System (ADS)

Beheshti, Alireza

2018-03-01

The contribution addresses the finite element analysis of bending of plates given the Kirchhoff-Love model. To analyze the static deformation of plates with different loadings and geometries, the principle of virtual work is used to extract the weak form. Following deriving the strain field, stresses and resultants may be obtained. For constructing four-node quadrilateral plate elements, the Hermite polynomials defined with respect to the variables in the parent space are applied explicitly. Based on the approximated field of displacement, the stiffness matrix and the load vector in the finite element method are obtained. To demonstrate the performance of the subparametric 4-node plate elements, some known, classical examples in structural mechanics are solved and there are comparisons with the analytical solutions available in the literature.

Improved assumed-stress hybrid shell element with drilling degrees of freedom for linear stress, buckling, and free vibration analyses

NASA Technical Reports Server (NTRS)

Rengarajan, Govind; Aminpour, Mohammad A.; Knight, Norman F., Jr.

1992-01-01

An improved four-node quadrilateral assumed-stress hybrid shell element with drilling degrees of freedom is presented. The formulation is based on Hellinger-Reissner variational principle and the shape functions are formulated directly for the four-node element. The element has 12 membrane degrees of freedom and 12 bending degrees of freedom. It has nine independent stress parameters to describe the membrane stress resultant field and 13 independent stress parameters to describe the moment and transverse shear stress resultant field. The formulation encompasses linear stress, linear buckling, and linear free vibration problems. The element is validated with standard tests cases and is shown to be robust. Numerical results are presented for linear stress, buckling, and free vibration analyses.

Expert system for identification of simultaneous and sequential reactor fuel failures with gas tagging

DOEpatents

Gross, Kenny C.

1994-01-01

Failure of a fuel element in a nuclear reactor core is determined by a gas tagging failure detection system and method. Failures are catalogued and characterized after the event so that samples of the reactor's cover gas are taken at regular intervals and analyzed by mass spectroscopy. Employing a first set of systematic heuristic rules which are applied in a transformed node space allows the number of node combinations which must be processed within a barycentric algorithm to be substantially reduced. A second set of heuristic rules treats the tag nodes of the most recent one or two leakers as "background" gases, further reducing the number of trial node combinations. Lastly, a "fuzzy" set theory formalism minimizes experimental uncertainties in the identification of the most likely volumes of tag gases. This approach allows for the identification of virtually any number of sequential leaks and up to five simultaneous gas leaks from fuel elements.

A finite element head and neck model as a supportive tool for deformable image registration.

PubMed

Kim, Jihun; Saitou, Kazuhiro; Matuszak, Martha M; Balter, James M

2016-07-01

A finite element (FE) head and neck model was developed as a tool to aid investigations and development of deformable image registration and patient modeling in radiation oncology. Useful aspects of a FE model for these purposes include ability to produce realistic deformations (similar to those seen in patients over the course of treatment) and a rational means of generating new configurations, e.g., via the application of force and/or displacement boundary conditions. The model was constructed based on a cone-beam computed tomography image of a head and neck cancer patient. The three-node triangular surface meshes created for the bony elements (skull, mandible, and cervical spine) and joint elements were integrated into a skeletal system and combined with the exterior surface. Nodes were additionally created inside the surface structures which were composed of the three-node triangular surface meshes, so that four-node tetrahedral FE elements were created over the whole region of the model. The bony elements were modeled as a homogeneous linear elastic material connected by intervertebral disks. The surrounding tissues were modeled as a homogeneous linear elastic material. Under force or displacement boundary conditions, FE analysis on the model calculates approximate solutions of the displacement vector field. A FE head and neck model was constructed that skull, mandible, and cervical vertebrae were mechanically connected by disks. The developed FE model is capable of generating realistic deformations that are strain-free for the bony elements and of creating new configurations of the skeletal system with the surrounding tissues reasonably deformed. The FE model can generate realistic deformations for skeletal elements. In addition, the model provides a way of evaluating the accuracy of image alignment methods by producing a ground truth deformation and correspondingly simulated images. The ability to combine force and displacement conditions provides flexibility for simulating realistic anatomic configurations.

International Space Station Atmosphere Control and Supply, Atmosphere Revitalization, and Water Recovery and Management Subsystem - Verification for Node 1

NASA Technical Reports Server (NTRS)

Williams, David E.

2007-01-01

The International Space Station (ISS) Node 1 Environmental Control and Life Support (ECLS) System is comprised of five subsystems: Atmosphere Control and Supply (ACS), Atmosphere Revitalization (AR), Fire Detection and Suppression (FDS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). This paper provides a summary of the nominal operation of the Node 1 ACS, AR, and WRM design and detailed Element Verification methodologies utilized during the Qualification phase for Node 1.

A prospective single-center study of sentinel lymph node detection in cervical carcinoma: is there a place in clinical practice?

PubMed

Devaja, Omer; Mehra, Gautam; Coutts, Michael; Montalto, Stephen Attard; Donaldson, John; Kodampur, Mallikarjun; Papadopoulos, Andreas John

2012-07-01

To establish the accuracy of sentinel lymph node (SLN) detection in early cervical cancer. Sentinel lymph node detection was performed prospectively over a 6-year period in 86 women undergoing surgery for cervical carcinoma by the combined method (Tc-99m and methylene blue dye). Further ultrastaging was performed on a subgroup of 26 patients who had benign SLNs on initial routine histological examination. The SLN was detected in 84 (97.7%) of 86 women by the combined method. Blue dye uptake was not seen in 8 women (90.7%). Sentinel lymph nodes were detected bilaterally in 63 women (73.3%), and the external iliac region was the most common anatomic location (48.8%). The median SLN count was 3 nodes (range, 1-7). Of the 84 women with sentinel node detection, 65 also underwent bilateral pelvic lymph node dissection, and in none of these cases was a benign SLN associated with a malignant non-SLN (100% negative predictive value). The median non-SLN count for all patients was 19 nodes (range, 8-35). Eighteen patients underwent removal of the SLN without bilateral pelvic lymph node dissection. Nine women (10.5%) had positive lymph nodes on final histology. One patient had bulky pelvic nodes on preoperative imaging and underwent removal of the negative bulky malignant lymph nodes and a benign SLN on the contralateral side. This latter case confirms the unreliability of the SLN method with bulky nodes. The remaining 8 patients had positive SLNs with negative nonsentinel lymph nodes. Fifty-nine SLNs from 26 patients, which were benign on initial routine histology, underwent ultrastaging, but no further disease was identified. Four patients (5%) relapsed after a median follow-up of 28 months (range, 8-80 months). Sentinel lymph node detection is an accurate and safe method in the assessment of nodal status in early cervical carcinoma.

KSC-04pd1676

NASA Image and Video Library

2004-08-24

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, a worker observes data from the Traveled Work Systems Test (TWST) conducted on the Node 2. The TWST executes open work that traveled with the Node 2 from Italy and simulates the on-orbit activation sequence. Node 2 was powered up Aug. 19 for the testing. The second of three Space Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Node 2 is scheduled to launch on mission STS-120, assembly flight 10A to the International Space Station.

Mechanical end joint system for structural column elements

NASA Technical Reports Server (NTRS)

Bush, H. G.; Wallsom, R. E. (Inventor)

1982-01-01

A mechanical end joint system, useful for the transverse connection of strut elements to a common node, comprises a node joint half with a semicircular tongue and groove, and a strut joint half with a semicircular tongue and groove. The two joint halves are engaged transversely and the connection is made secure by the inherent physical property characteristics of locking latches and/or by a spring-actioned shaft. A quick release mechanism provides rapid disengagement of the joint halves.

Tree bark suber-included particles: A long-term accumulation site for elements of atmospheric origin

NASA Astrophysics Data System (ADS)

Catinon, Mickaël; Ayrault, Sophie; Spadini, Lorenzo; Boudouma, Omar; Asta, Juliette; Tissut, Michel; Ravanel, Patrick

2011-02-01

The deposition of atmospheric elements on and into the bark of 4-year-old Fraxinus excelsior L. was studied. The elemental composition of the suber tissue was established through ICP-MS analysis and the presence of solid mineral particles included in this suber was established and described through SEM-EDX. Fractionation of the suber elements mixture was obtained after ashing at 550 °C through successive water (C fraction) and HNO 3 2 M (D fraction) extraction, leading to an insoluble residue mainly composed of the solid mineral particles (E fraction). The triplicated % weight of C, D and E were respectively 34.4 ± 2.7, 64.8 ± 2.7 and 0.8 ± 0.1% of the suber ashes weight. The main component of C was K, of D was Ca. Noticeable amounts of Mg were also observed in D. The E fraction, composed of insoluble particles, was mostly constituted of geogenic products, with elements such as Si, Al, K, Mg, representing primary minerals. E also contained Ca 3(PO 4) 2 and concentrated the main part of Pb and Fe. Moreover, The SEM-EDX analysis evidenced that this fraction also concentrated several types of fly ashes of industrial origin. The study of the distribution between C, D and E was analysed through ICP-MS with respect to their origin. The origin of the elements found in such bark was either geogenic (clay, micas, quartz…), anthropogenic or biogenic (for instance large amounts of solid Ca organic salts having a storage role). As opposed to the E fraction, the C fraction, mainly composed of highly soluble K+ is characteristic of a biological pool of plant origin. In fraction D, the very high amount of Ca++ corresponds to two different origins: biological or acid soluble minerals such as calcite. Furthermore, the D fraction contains the most part of pollutants of anthropic origin such as Zn, Cu, Ni, Co, Cd. As a whole, the fractionation procedure of the suber samples allows to separate elements as a function of their origin but also gives valuable information on distribution and speciation of trace elements.

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, the U.S. Node 2 (center) and the Japanese Experiment Module (JEM), background right, await a Multi-Element Integrated Test (MEIT). Node 2 attaches to the end of the U.S. Lab on the International Space Station and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The National Space Development Agency of Japan (NASDA) developed their laboratory at the Tsukuba Space Center near Tokyo. It is the first element, named "Kibo" (Hope), to be delivered to KSC. The JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

NASA Image and Video Library

2003-08-27

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, the U.S. Node 2 (center) and the Japanese Experiment Module (JEM), background right, await a Multi-Element Integrated Test (MEIT). Node 2 attaches to the end of the U.S. Lab on the International Space Station and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The National Space Development Agency of Japan (NASDA) developed their laboratory at the Tsukuba Space Center near Tokyo. It is the first element, named "Kibo" (Hope), to be delivered to KSC. The JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

12-Chemokine Gene Signature Identifies Lymph Node-like Structures in Melanoma: Potential for Patient Selection for Immunotherapy?

NASA Astrophysics Data System (ADS)

Messina, Jane L.; Fenstermacher, David A.; Eschrich, Steven; Qu, Xiaotao; Berglund, Anders E.; Lloyd, Mark C.; Schell, Michael J.; Sondak, Vernon K.; Weber, Jeffrey S.; Mulé, James J.

2012-10-01

We have interrogated a 12-chemokine gene expression signature (GES) on genomic arrays of 14,492 distinct solid tumors and show broad distribution across different histologies. We hypothesized that this 12-chemokine GES might accurately predict a unique intratumoral immune reaction in stage IV (non-locoregional) melanoma metastases. The 12-chemokine GES predicted the presence of unique, lymph node-like structures, containing CD20+ B cell follicles with prominent areas of CD3+ T cells (both CD4+ and CD8+ subsets). CD86+, but not FoxP3+, cells were present within these unique structures as well. The direct correlation between the 12-chemokine GES score and the presence of unique, lymph nodal structures was also associated with better overall survival of the subset of melanoma patients. The use of this novel 12-chemokine GES may reveal basic information on in situ mechanisms of the anti-tumor immune response, potentially leading to improvements in the identification and selection of melanoma patients most suitable for immunotherapy.

Turbine Engine Component Analysis: Cantilevered Composite Flat Plate Analysis

DTIC Science & Technology

1989-11-01

4/5 element which translates into the ADIN. shell element (Type 7) with thickness correction. PATADI automatically generates midsurface normal vectors...for each node referenced by a shell element. Using thickness correction, the element thickness will be oriented along the midsurface direction. If no

THE COMPOSITION OF INTERSTELLAR GRAINS TOWARD ζ OPHIUCHI: CONSTRAINING THE ELEMENTAL BUDGET NEAR THE DIFFUSE-DENSE CLOUD TRANSITION

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

Poteet, Charles A.; Whittet, Douglas C. B.; Draine, Bruce T., E-mail: charles.poteet@gmail.com

2015-03-10

We investigate the composition of interstellar grains along the line of sight toward ζ Ophiuchi, a well-studied environment near the diffuse-dense cloud transition. A spectral decomposition analysis of the solid-state absorbers is performed using archival spectroscopic observations from the Spitzer Space Telescope and Infrared Space Observatory. We find strong evidence for the presence of sub-micron-sized amorphous silicate grains, principally comprised of olivine-like composition, with no convincing evidence of H{sub 2}O ice mantles. However, tentative evidence for thick H{sub 2}O ice mantles on large (a ≈ 2.8 μm) grains is presented. Solid-state abundances of elemental Mg, Si, Fe, and O aremore » inferred from our analysis and compared to standard reference abundances. We find that nearly all of the Mg and Si atoms along the line of sight reside in amorphous silicate grains, while a substantial fraction of the elemental Fe resides in compounds other than silicates. Moreover, we find that the total abundance of elemental O is largely inconsistent with the adopted reference abundances, indicating that as much as ∼156 ppm of interstellar O is missing along the line of sight. After taking into account additional limits on the abundance of elemental O in other O-bearing solids, we conclude that any missing reservoir of elemental O must reside on large grains that are nearly opaque to infrared radiation.« less

Reissner-Mindlin Legendre Spectral Finite Elements with Mixed Reduced Quadrature

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

Brito, K. D.; Sprague, M. A.

2012-10-01

Legendre spectral finite elements (LSFEs) are examined through numerical experiments for static and dynamic Reissner-Mindlin plate bending and a mixed-quadrature scheme is proposed. LSFEs are high-order Lagrangian-interpolant finite elements with nodes located at the Gauss-Lobatto-Legendre quadrature points. Solutions on unstructured meshes are examined in terms of accuracy as a function of the number of model nodes and total operations. While nodal-quadrature LSFEs have been shown elsewhere to be free of shear locking on structured grids, locking is demonstrated here on unstructured grids. LSFEs with mixed quadrature are, however, locking free and are significantly more accurate than low-order finite-elements for amore » given model size or total computation time.« less

Enabling a high throughput real time data pipeline for a large radio telescope array with GPUs

NASA Astrophysics Data System (ADS)

Edgar, R. G.; Clark, M. A.; Dale, K.; Mitchell, D. A.; Ord, S. M.; Wayth, R. B.; Pfister, H.; Greenhill, L. J.

2010-10-01

The Murchison Widefield Array (MWA) is a next-generation radio telescope currently under construction in the remote Western Australia Outback. Raw data will be generated continuously at 5 GiB s-1, grouped into 8 s cadences. This high throughput motivates the development of on-site, real time processing and reduction in preference to archiving, transport and off-line processing. Each batch of 8 s data must be completely reduced before the next batch arrives. Maintaining real time operation will require a sustained performance of around 2.5 TFLOP s-1 (including convolutions, FFTs, interpolations and matrix multiplications). We describe a scalable heterogeneous computing pipeline implementation, exploiting both the high computing density and FLOP-per-Watt ratio of modern GPUs. The architecture is highly parallel within and across nodes, with all major processing elements performed by GPUs. Necessary scatter-gather operations along the pipeline are loosely synchronized between the nodes hosting the GPUs. The MWA will be a frontier scientific instrument and a pathfinder for planned peta- and exa-scale facilities.

Preparation and properties of Ba xSr 1- xCo yFe 1- yO 3- δ cathode material for intermediate temperature solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Zhao, Hailei; Shen, Wei; Zhu, Zhiming; Li, Xue; Wang, Zhifeng

Ba xSr 1- xCo yFe 1- yO 3- δ (BSCF) materials with perovskite structure were synthesized via solid-state reaction. Their structural characteristics, electrical-conduction behavior and cathode performance were investigated. Compared to A-site elements, B-site elements show a wide solid-solution range in BSCF. The electrical-conduction behavior of BSCF obeys the small polaron-hopping mechanism. An increase of Ba or Co content in the BSCF samples results in a decrease of electrical conductivity, which is mainly attributable to the preferential existence of B 3+ rather than B 4+ in Ba- or Co-rich samples. At the same time, this leads to increases in the lattice parameter a and the number of oxygen vacancies. BSCF samples with high Ba content show a high structural stability (high oxygen-loss temperature). Ba 0.6Sr 0.4Co 0.8Fe 0.2O 3- δ and Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3- δ materials present good thermal-cycling stability of the electrical conductivity. Compared with Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3- δ, Ba 0.6Sr 0.4Co 0.8Fe 0.2O 3- δ exhibits a better cathode performance in a Ce 0.8Gd 0.2O 2- δ (GDC)-supported half cell. The cell performance can be improved by introducing a certain amount of GDC electrolyte into the BSCF cathode material.

Elemental balance of SRF production process: solid recovered fuel produced from municipal solid waste.

PubMed

Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Oinas, Pekka

2016-01-01

In the production of solid recovered fuel (SRF), certain waste components have excessive influence on the quality of product. The proportion of rubber, plastic (hard) and certain textiles was found to be critical as to the elemental quality of SRF. The mass flow of rubber, plastic (hard) and textiles (to certain extent, especially synthetic textile) components from input waste stream into the output streams of SRF production was found to play the decisive role in defining the elemental quality of SRF. This paper presents the mass flow of polluting and potentially toxic elements (PTEs) in SRF production. The SRF was produced from municipal solid waste (MSW) through mechanical treatment (MT). The results showed that of the total input chlorine content to process, 55% was found in the SRF and 30% in reject material. Of the total input arsenic content, 30% was found in the SRF and 45% in fine fraction. In case of cadmium, lead and mercury, of their total input content to the process, 62%, 38% and 30%, respectively, was found in the SRF. Among the components of MSW, rubber material was identified as potential source of chlorine, containing 8.0 wt.% of chlorine. Plastic (hard) and textile components contained 1.6 and 1.1. wt.% of chlorine, respectively. Plastic (hard) contained higher lead and cadmium content compared with other waste components, i.e. 500 mg kg(-1) and 9.0 mg kg(-1), respectively. © The Author(s) 2015.

Early diagnosis of lymph node metastasis: Importance of intranodal pressures.

PubMed

Miura, Yoshinobu; Mikada, Mamoru; Ouchi, Tomoki; Horie, Sachiko; Takeda, Kazu; Yamaki, Teppei; Sakamoto, Maya; Mori, Shiro; Kodama, Tetsuya

2016-03-01

Regional lymph node status is an important prognostic indicator of tumor aggressiveness. However, early diagnosis of metastasis using intranodal pressure, at a stage when lymph node size has not changed significantly, has not been investigated. Here, we use an MXH10/Mo-lpr/lpr mouse model of lymph node metastasis to show that intranodal pressure increases in both the subiliac lymph node and proper axillary lymph node, which are connected by lymphatic vessels, when tumor cells are injected into the subiliac lymph node to induce metastasis to the proper axillary lymph node. We found that intranodal pressure in the subiliac lymph node increased at the stage when metastasis was detected by in vivo bioluminescence, but when proper axillary lymph node volume (measured by high-frequency ultrasound imaging) had not increased significantly. Intravenously injected liposomes, encapsulating indocyanine green, were detected in solid tumors by in vivo bioluminescence, but not in the proper axillary lymph node. Basic blood vessel and lymphatic channel structures were maintained in the proper axillary lymph node, although sinus histiocytosis was detected. These results show that intranodal pressure in the proper axillary lymph node increases at early stages when metastatic tumor cells have not fully proliferated. Intranodal pressure may be a useful parameter for facilitating early diagnosis of lymph node metastasis. © 2015 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Analysis of Flexible Bars and Frames with Large Displacements of Nodes By Finite Element Method in the Form of Classical Mixed Method

NASA Astrophysics Data System (ADS)

Ignatyev, A. V.; Ignatyev, V. A.; Onischenko, E. V.

2017-11-01

This article is the continuation of the work made bt the authors on the development of the algorithms that implement the finite element method in the form of a classical mixed method for the analysis of geometrically nonlinear bar systems [1-3]. The paper describes an improved algorithm of the formation of the nonlinear governing equations system for flexible plane frames and bars with large displacements of nodes based on the finite element method in a mixed classical form and the use of the procedure of step-by-step loading. An example of the analysis is given.

Finite Element Analysis of the LOLA Receiver Telescope Lens

NASA Technical Reports Server (NTRS)

Matzinger, Elizabeth

2007-01-01

This paper presents the finite element stress and distortion analysis completed on the Receiver Telescope lens of the Lunar Orbiter Laser Altimeter (LOLA). LOLA is one of six instruments on the Lunar Reconnaissance Orbiter (LRO), scheduled to launch in 2008. LOLA's main objective is to produce a high-resolution global lunar topographic model to aid in safe landings and enhance surface mobility in future exploration missions. The Receiver Telescope captures the laser pulses transmitted through a diffractive optical element (DOE) and reflected off the lunar surface. The largest lens of the Receiver Telescope, Lens 1, is a 150 mm diameter aspheric lens originally designed to be made of BK7 glass. The finite element model of the Receiver Telescope Lens 1 is comprised of solid elements and constrained in a manner consistent with the behavior of the mounting configuration of the Receiver Telescope tube. Twenty-one temperature load cases were mapped to the nodes based on thermal analysis completed by LOLA's lead thermal analyst, and loads were applied to simulate the preload applied from the ring flexure. The thermal environment of the baseline design (uncoated BK7 lens with no baffle) produces large radial and axial gradients in the lens. These large gradients create internal stresses that may lead to part failure, as well as significant bending that degrades optical performance. The high stresses and large distortions shown in the analysis precipitated a design change from BK7 glass to sapphire.

Lunar tidal acceleration obtained from satellite-derived ocean tide parameters

NASA Technical Reports Server (NTRS)

Goad, C. C.; Douglas, B. C.

1978-01-01

Observation equations for the M2 ocean tide are computed from Geos 3 data for the long periodic variations of the inclination and node of the orbit. M2 ocean tide parameter values C22+ = 3.23 + or - 0.25 cm, epsilon 22+ = 331 + or - 6 deg, and epsilon 42+ = 113 + or - 6 deg are determined. With the assumption of zero solid tide phase lag, the lunar tidal acceleration is mostly (85%) due to the C22+ term in the expansion of the M2 tide with additional small contributions from the O1 and N2 tides. The calculated value for the tidal acceleration in lunar longitude is -27.4 + or - 3 arc sec/sq (100 yr) which is similar to values determined from astronomical data. The mean elements of Geos 3 are presented in tabular form.

Long Term Mean Local Time of the Ascending Node Prediction

NASA Technical Reports Server (NTRS)

McKinley, David P.

2007-01-01

Significant error has been observed in the long term prediction of the Mean Local Time of the Ascending Node on the Aqua spacecraft. This error of approximately 90 seconds over a two year prediction is a complication in planning and timing of maneuvers for all members of the Earth Observing System Afternoon Constellation, which use Aqua's MLTAN as the reference for their inclination maneuvers. It was determined that the source of the prediction error was the lack of a solid Earth tide model in the operational force models. The Love Model of the solid Earth tide potential was used to derive analytic corrections to the inclination and right ascension of the ascending node of Aqua's Sun-synchronous orbit. Additionally, it was determined that the resonance between the Sun and orbit plane of the Sun-synchronous orbit is the primary driver of this error. The analytic corrections have been added to the operational force models for the Aqua spacecraft reducing the two-year 90-second error to less than 7 seconds.

KSC-04PD-0148

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Astronaut Tim Kopra (second from right) talks with workers in the Space Station Processing Facility about the Intravehicular Activity (IVA) constraints testing on the Italian-built Node 2, a future element of the International Space Station. . The second of three Station connecting modules, the Node 2 attaches to the end of the U.S. Lab and provides attach locations for several other elements. Kopra is currently assigned technical duties in the Space Station Branch of the Astronaut Office, where his primary focus involves the testing of crew interfaces for two future ISS modules as well as the implementation of support computers and operational Local Area Network on ISS. Node 2 is scheduled to launch on mission STS-120, Station assembly flight 10A.

Arbitrary-level hanging nodes for adaptive hphp-FEM approximations in 3D

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

Pavel Kus; Pavel Solin; David Andrs

2014-11-01

In this paper we discuss constrained approximation with arbitrary-level hanging nodes in adaptive higher-order finite element methods (hphp-FEM) for three-dimensional problems. This technique enables using highly irregular meshes, and it greatly simplifies the design of adaptive algorithms as it prevents refinements from propagating recursively through the finite element mesh. The technique makes it possible to design efficient adaptive algorithms for purely hexahedral meshes. We present a detailed mathematical description of the method and illustrate it with numerical examples.

Multi-element microelectropolishing method

DOEpatents

Lee, Peter J.

1994-01-01

A method is provided for microelectropolishing a transmission electron microscopy nonhomogeneous multi-element compound foil. The foil is electrolyzed at different polishing rates for different elements by rapidly cycling between different current densities. During a first portion of each cycle at a first voltage a first element electrolyzes at a higher current density than a second element such that the material of the first element leaves the anode foil at a faster rate than the second element and creates a solid surface film, and such that the solid surface film is removed at a faster rate than the first element leaves the anode foil. During a second portion of each cycle at a second voltage the second element electrolyzes at a higher current density than the first element, and the material of the second element leaves the anode foil at a faster rate than the first element and creates a solid surface film, and the solid surface film is removed at a slower rate than the second element leaves the foil. The solid surface film is built up during the second portion of the cycle, and removed during the first portion of the cycle.

Adaptive Data Gathering in Mobile Sensor Networks Using Speedy Mobile Elements

PubMed Central

Lai, Yongxuan; Xie, Jinshan; Lin, Ziyu; Wang, Tian; Liao, Minghong

2015-01-01

Data gathering is a key operator for applications in wireless sensor networks; yet it is also a challenging problem in mobile sensor networks when considering that all nodes are mobile and the communications among them are opportunistic. This paper proposes an efficient data gathering scheme called ADG that adopts speedy mobile elements as the mobile data collector and takes advantage of the movement patterns of the network. ADG first extracts the network meta-data at initial epochs, and calculates a set of proxy nodes based on the meta-data. Data gathering is then mapped into the Proxy node Time Slot Allocation (PTSA) problem that schedules the time slots and orders, according to which the data collector could gather the maximal amount of data within a limited period. Finally, the collector follows the schedule and picks up the sensed data from the proxy nodes through one hop of message transmissions. ADG learns the period when nodes are relatively stationary, so that the collector is able to pick up the data from them during the limited data gathering period. Moreover, proxy nodes and data gathering points could also be timely updated so that the collector could adapt to the change of node movements. Extensive experimental results show that the proposed scheme outperforms other data gathering schemes on the cost of message transmissions and the data gathering rate, especially under the constraint of limited data gathering period. PMID:26389903

Maraging superalloys and heat treatment processes

DOEpatents

Korenko, Michael K.; Gelles, David S.; Thomas, Larry E.

1986-01-01

Described herein are nickel-chromium-iron maraging, gamma prime strengthened superalloys containing about 18 to 25 weight percent nickel, about 4 to 8 weight percent chromium, gamma prime forming elements such as aluminum and/or titanium, and a solid solution strengthening element, such as molybdenum. After heat treatment, which includes at least one ausaging treatment and at least one maraging treatment, a microstructure containing gamma prime phase and decomposed Fe-Ni-Cr type martensite is produced.

Boundary elements; Proceedings of the Fifth International Conference, Hiroshima, Japan, November 8-11, 1983

NASA Astrophysics Data System (ADS)

Brebbia, C. A.; Futagami, T.; Tanaka, M.

The boundary-element method (BEM) in computational fluid and solid mechanics is examined in reviews and reports of theoretical studies and practical applications. Topics presented include the fundamental mathematical principles of BEMs, potential problems, EM-field problems, heat transfer, potential-wave problems, fluid flow, elasticity problems, fracture mechanics, plates and shells, inelastic problems, geomechanics, dynamics, industrial applications of BEMs, optimization methods based on the BEM, numerical techniques, and coupling.

Network topology of olivine-basalt partial melts

NASA Astrophysics Data System (ADS)

Skemer, Philip; Chaney, Molly M.; Emmerich, Adrienne L.; Miller, Kevin J.; Zhu, Wen-lu

2017-07-01

The microstructural relationship between melt and solid grains in partially molten rocks influences many physical properties, including permeability, rheology, electrical conductivity and seismic wave speeds. In this study, the connectivity of melt networks in the olivine-basalt system is explored using a systematic survey of 3-D X-ray microtomographic data. Experimentally synthesized samples with 2 and 5 vol.% melt are analysed as a series of melt tubules intersecting at nodes. Each node is characterized by a coordination number (CN), which is the number of melt tubules that intersect at that location. Statistically representative volumes are described by coordination number distributions (CND). Polyhedral grains can be packed in many configurations yielding different CNDs, however widely accepted theory predicts that systems with small dihedral angles, such as olivine-basalt, should exhibit a predominant CN of four. In this study, melt objects are identified with CN = 2-8, however more than 50 per cent are CN = 4, providing experimental verification of this theoretical prediction. A conceptual model that considers the role of heterogeneity in local grain size and melt fraction is proposed to explain the formation of nodes with CN ≠ 4. Correctly identifying the melt network topology is essential to understanding the relationship between permeability and porosity, and hence the transport properties of partial molten mantle rocks.

International Space Station Temperature and Humidity Control Subsystem Verification for Node 1

NASA Technical Reports Server (NTRS)

Williams, David E.

2007-01-01

The International Space Station (ISS) Node 1 Environmental Control and Life Support (ECLS) System is comprised of five subsystems: Atmosphere Control and Supply (ACS), Atmosphere Revitalization (AR), Fire Detection and Suppression (FDS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). This paper provides a summary of the nominal operation of the Node 1 THC subsystem design. The paper will also provide a discussion of the detailed Element Verification methodologies for nominal operation of the Node 1 THC subsystem operations utilized during the Qualification phase.

Spectral Element Method for the Simulation of Unsteady Compressible Flows

NASA Technical Reports Server (NTRS)

Diosady, Laslo Tibor; Murman, Scott M.

2013-01-01

This work uses a discontinuous-Galerkin spectral-element method (DGSEM) to solve the compressible Navier-Stokes equations [1{3]. The inviscid ux is computed using the approximate Riemann solver of Roe [4]. The viscous fluxes are computed using the second form of Bassi and Rebay (BR2) [5] in a manner consistent with the spectral-element approximation. The method of lines with the classical 4th-order explicit Runge-Kutta scheme is used for time integration. Results for polynomial orders up to p = 15 (16th order) are presented. The code is parallelized using the Message Passing Interface (MPI). The computations presented in this work are performed using the Sandy Bridge nodes of the NASA Pleiades supercomputer at NASA Ames Research Center. Each Sandy Bridge node consists of 2 eight-core Intel Xeon E5-2670 processors with a clock speed of 2.6Ghz and 2GB per core memory. On a Sandy Bridge node the Tau Benchmark [6] runs in a time of 7.6s.

Three-dimensional elastic-plastic finite-element analysis of fatigue crack propagation

NASA Technical Reports Server (NTRS)

Goglia, G. L.; Chermahini, R. G.

1985-01-01

Fatigue cracks are a major problem in designing structures subjected to cyclic loading. Cracks frequently occur in structures such as aircraft and spacecraft. The inspection intervals of many aircraft structures are based on crack-propagation lives. Therefore, improved prediction of propagation lives under flight-load conditions (variable-amplitude loading) are needed to provide more realistic design criteria for these structures. The main thrust was to develop a three-dimensional, nonlinear, elastic-plastic, finite element program capable of extending a crack and changing boundary conditions for the model under consideration. The finite-element model is composed of 8-noded (linear-strain) isoparametric elements. In the analysis, the material is assumed to be elastic-perfectly plastic. The cycle stress-strain curve for the material is shown Zienkiewicz's initial-stress method, von Mises's yield criterion, and Drucker's normality condition under small-strain assumptions are used to account for plasticity. The three-dimensional analysis is capable of extending the crack and changing boundary conditions under cyclic loading.

Clinical significance of the anterosuperior lymph nodes along the common hepatic artery identified by sentinel node mapping in patients with gastric cancer.

PubMed

Shimada, Ayako; Takeuchi, Hiroya; Kamiya, Satoshi; Fukuda, Kazumasa; Nakamura, Rieko; Takahashi, Tsunehiro; Wada, Norihito; Kawakubo, Hirofumi; Saikawa, Yoshiro; Omori, Tai; Nakahara, Tadaki; Jinzaki, Masahiro; Murakami, Koji; Kitagawa, Yuko

2016-10-01

The sentinel node (SN) concept is safely applied and validated in early gastric cancer. Gastric lymph nodes are divided into five basins with the main gastric arteries, and the anterosuperior lymph nodes with the common hepatic artery (No. 8a) are classified in the right gastric artery (r-GA) basin. Although No. 8a are considered to have lymphatic flow from the r-GA basin, there might be additional multiple lymphatic flows into No. 8a. The aim of this study is to analyze the lymphatic flows to No. 8a and to investigate the clinical significance of No. 8a as a sentinel node (SN No. 8a). Four hundred and twenty-nine patients with cT1N0 or cT2N0 gastric cancer underwent SN mapping. We used technetium-99 tin colloid solution and blue dye as a tracer. We detected SN No. 8a in 35 (8.2 %) patients. In these patients, we detected SN No. 8a with SNs that belonged to the left gastric artery (l-GA) basin (66 %), right gastroepiploic artery (r-GEA) basin (54 %), and right gastric artery (r-GA) basin (46 %). In addition, celiac artery lymph nodes were detected as SNs significantly more frequently. Function-preserving surgery was performed significantly less often in patients with SN No. 8a (p =0.018). We found that SN No. 8a seemed to have lymphatic flow not only from the r-GA basin, but also from the l-GA basin or r-GEA basin. When SN No. 8a are detected, we should be careful to perform function-preserving surgery, even in SN-negative cases.

Robust, transformable, and crystalline single-node organometallic networks constructed from ditopic m-terphenyl isocyanides

DOE PAGES

Agnew, Douglas W.; Gembicky, Milan; Moore, Curtis E.; ...

2016-11-01

Here, the preparation of 3D and 2D Cu(I) coordination networks using ditopic m-terphenyl isocyanides is described. The incorporation of sterically encumbering substituents enables the controlled, solid-state preparation of Cu(I) tris-isocyanide nodes with a labile solvent ligand in a manner mirroring solution-phase chemistry of monomeric complexes. The protection afforded by the m-terphenyl groups is also shown to engender significant stability towards heat as well as acidic or basic conditions, resulting in robust single-metal-node networks that can transition from 3D to 2D extended structures.

Structure and Dynamics of Zr6O8 Metal-Organic Framework Node Surfaces Probed with Ethanol Dehydration as a Catalytic Test Reaction.

PubMed

Yang, Dong; Ortuño, Manuel A; Bernales, Varinia; Cramer, Christopher J; Gagliardi, Laura; Gates, Bruce C

2018-03-14

Some metal-organic frameworks (MOFs) incorporate nodes that are metal oxide clusters such as Zr 6 O 8 . Vacancies on the node surfaces, accidental or by design, act as catalytic sites. Here, we report elucidation of the chemistry of Zr 6 O 8 nodes in the MOFs UiO-66 and UiO-67 having used infrared and nuclear magnetic resonance spectroscopies to determine the ligands on the node surfaces originating from the solvents and modifiers used in the syntheses and having elucidated the catalytic properties of the nodes for ethanol dehydration, which takes place selectively to make diethyl ether but not ethylene at 473-523 K. Density functional theory calculations show that the key to the selective catalysis is the breaking of node-linker bonds (or the accidental adjacency of open/defect sites) that allows catalytically fruitful bonding of the reactant ethanol to neighboring sites on the nodes, facilitating the bimolecular ether formation through an S N 2 mechanism.

Analysis of interlaminar stresses in symmetric and unsymmetric laminates under various loadings

NASA Astrophysics Data System (ADS)

Leger, C. A.; Chan, W. S.

1993-04-01

A quasi-three-dimensional finite-element model is developed to investigate the interlaminar stresses in a composite laminate under combined loadings. An isoparametric quadrilateral element with eight nodes and three degrees of freedom per node is the finite element used in this study. The element is used to model a composite laminate cross section loaded by tension, torsion, transverse shear, and both beam and chord bending which are representative of loading in a helicopter rotor system. Symmetric and unsymmetric laminates are examined with comparisons made between the interlaminar stress distributions and magnitudes for each laminate. Unsymmetric results are compared favorably to limited results found in literature. The unsymmetric interlaminar normal stress distribution in a symmetric laminate containing a free edge delamination is also examined.

A critical evaluation of lymph node ratio in head and neck cancer.

PubMed

de Ridder, M; Marres, C C M; Smeele, L E; van den Brekel, M W M; Hauptmann, M; Balm, A J M; van Velthuysen, M L F

2016-12-01

In head and neck squamous cell carcinoma (HNSCC), the search for better prognostic factors beyond TNM-stage is ongoing. Lymph node ratio (LNR) (positive lymph nodes/total lymph nodes) is gaining interest in view of its potential prognostic significance. All HNSCC patients at the Netherlands Cancer Institute undergoing neck dissection for lymph node metastases in the neck region between 2002 and 2012 (n = 176) were included. Based on a protocol change in specimen processing, the cohort was subdivided in two distinct consecutive periods (pre and post 2007). The prognostic value of LNR, N-stage, and number of positive lymph nodes for overall survival was assessed. The mean number of examined lymph nodes after 2007 was significantly higher (42.3) than before (35.8) (p = 0.024). The higher number concerned mostly lymph nodes in level V. The mean number of positive lymph nodes before 2007 was 3.3 vs. 3.6 after 2007 (p = 0.745). By multivariate analysis of both pre- and post-2007 cohort data, two factors remained associated with an increased hazard of dying: N2 [HR 2.1 (1.1-4.1) and 2.4 (1.0-5.8)] and >3 positive lymph nodes [HR 2.0 (1.1-3.5) and 3.1 (1.4-6.9)]. Hazard ratio for LNR >7 % was not significantly different: pre 2007 at 2.2 (1.3-3.8) and post 2007 at 2.1 (1.0-4.8, p = 0.053). In this study, changes in specimen processing influenced LNR values, but not the total number of tumor positive nodes found. Therefore, in HNSCC, the number of positive nodes seems a more reliable parameter than LNR, provided a minimum number of lymph nodes are examined.

Modeling delamination growth in composites

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

Reedy, E.D. Jr.; Mello, F.J.

1996-12-01

A method for modeling the initiation and growth of discrete delaminations in shell-like composite structures is presented. The laminate is divided into two or more sublaminates, with each sublaminate modeled with four-noded quadrilateral shell elements. A special, eight-noded hex constraint element connects opposing sublaminate shell elements. It supplies the nodal forces and moments needed to make the two opposing shell elements act as a single shell element until a prescribed failure criterion is satisfied. Once the failure criterion is attained, the connection is broken, creating or growing a discrete delamination. This approach has been implemented in a 3D finite elementmore » code. This code uses explicit time integration, and can analyze shell-like structures subjected to large deformations and complex contact conditions. The shell elements can use existing composite material models that include in-plane laminate failure modes. This analysis capability was developed to perform crashworthiness studies of composite structures, and is useful whenever there is a need to estimate peak loads, energy absorption, or the final shape of a highly deformed composite structure. This paper describes the eight-noded hex constraint element used to model the initiation and growth of a delamination, and discusses associated implementation issues. Particular attention is focused on the delamination growth criterion, and it is verified that calculated results do not depend on element size. In addition, results for double cantilever beam and end notched flexure specimens are presented and compared to measured data to assess the ability of the present approach to model a growing delamination.« less

Expert system for identification of simultaneous and sequential reactor fuel failures with gas tagging

DOEpatents

Gross, K.C.

1994-07-26

Failure of a fuel element in a nuclear reactor core is determined by a gas tagging failure detection system and method. Failures are catalogued and characterized after the event so that samples of the reactor's cover gas are taken at regular intervals and analyzed by mass spectroscopy. Employing a first set of systematic heuristic rules which are applied in a transformed node space allows the number of node combinations which must be processed within a barycentric algorithm to be substantially reduced. A second set of heuristic rules treats the tag nodes of the most recent one or two leakers as background'' gases, further reducing the number of trial node combinations. Lastly, a fuzzy'' set theory formalism minimizes experimental uncertainties in the identification of the most likely volumes of tag gases. This approach allows for the identification of virtually any number of sequential leaks and up to five simultaneous gas leaks from fuel elements. 14 figs.

Multi-element microelectropolishing method

DOEpatents

Lee, P.J.

1994-10-11

A method is provided for microelectropolishing a transmission electron microscopy nonhomogeneous multi-element compound foil. The foil is electrolyzed at different polishing rates for different elements by rapidly cycling between different current densities. During a first portion of each cycle at a first voltage a first element electrolyzes at a higher current density than a second element such that the material of the first element leaves the anode foil at a faster rate than the second element and creates a solid surface film, and such that the solid surface film is removed at a faster rate than the first element leaves the anode foil. During a second portion of each cycle at a second voltage the second element electrolyzes at a higher current density than the first element, and the material of the second element leaves the anode foil at a faster rate than the first element and creates a solid surface film, and the solid surface film is removed at a slower rate than the second element leaves the foil. The solid surface film is built up during the second portion of the cycle, and removed during the first portion of the cycle. 10 figs.

Fem Formulation for Heat and Mass Transfer in Porous Medium

NASA Astrophysics Data System (ADS)

Azeem; Soudagar, Manzoor Elahi M.; Salman Ahmed, N. J.; Anjum Badruddin, Irfan

2017-08-01

Heat and mass transfer in porous medium can be modelled using three partial differential equations namely, momentum equation, energy equation and mass diffusion. These three equations are coupled to each other by some common terms that turn the whole phenomenon into a complex problem with inter-dependable variables. The current article describes the finite element formulation of heat and mass transfer in porous medium with respect to Cartesian coordinates. The problem under study is formulated into algebraic form of equations by using Galerkin's method with the help of two-node linear triangular element having three nodes. The domain is meshed with smaller sized elements near the wall region and bigger size away from walls.

Asynchronous Data Retrieval from an Object-Oriented Database

NASA Astrophysics Data System (ADS)

Gilbert, Jonathan P.; Bic, Lubomir

We present an object-oriented semantic database model which, similar to other object-oriented systems, combines the virtues of four concepts: the functional data model, a property inheritance hierarchy, abstract data types and message-driven computation. The main emphasis is on the last of these four concepts. We describe generic procedures that permit queries to be processed in a purely message-driven manner. A database is represented as a network of nodes and directed arcs, in which each node is a logical processing element, capable of communicating with other nodes by exchanging messages. This eliminates the need for shared memory and for centralized control during query processing. Hence, the model is suitable for implementation on a multiprocessor computer architecture, consisting of large numbers of loosely coupled processing elements.

[A patient with thyroid cancer evaluated according to Response Evaluation Criteria in Solid Tumors during treatment for breast cancer recurrence in hepatic and cervical lymph nodes].

PubMed

Hayashi, Keiko; Enomoto, Takumo; Oshida, Sayuri; Habiro, Takeyoshi; Hatate, Kazuhiko; Sengoku, Norihiko; Watanabe, Masahiko

2013-11-01

We describe a case of a 69-year-old woman who underwent left breast-preserving surgery and axillary dissection for left-sided breast cancer at 60 years of age. The histopathological diagnosis was papillotubular carcinoma, luminal A (pathological T1N0M0).In the eighth year after surgery, computed tomography (CT) revealed recurrence in the liver and cervical lymph node metastasis. The patient did not respond to 3 months of treatment with letrozole (progressive disease [PD]). Six courses of chemotherapy with epirubicin and cyclophosphamide (EC) were administered. Subsequently, the attending physician was replaced while the patient was receiving paclitaxel( PTX).After 4 courses of treatment with PTX, the liver metastasis disappeared (complete response [CR]).However, the cervical lymph nodes did not shrink (PD).The cytological diagnosis was papillary thyroid cancer with associated cervical lymph node metastasis. Total thyroidectomy and D3b cervical lymph node dissection were performed. The pathological diagnosis was pEx0T1bN1Mx, pStage IVA disease. Replacement of the attending physician is a critical turning point for patients. During chemotherapy or hormone therapy for breast cancer, each organ should be evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST).In the case of our patient, thyroid cancer was diagnosed according to RECIST. Cancer specialists should bear in mind that the treatment policy may change dramatically depending on the results of RECIST assessment.

Three-dimensional finite-element analysis of chevron-notched fracture specimens

NASA Technical Reports Server (NTRS)

Raju, I. S.; Newman, J. C., Jr.

1984-01-01

Stress-intensity factors and load-line displacements were calculated for chevron-notched bar and rod fracture specimens using a three-dimensional finite-element analysis. Both specimens were subjected to simulated wedge loading (either uniform applied displacement or uniform applied load). The chevron-notch sides and crack front were assumed to be straight. Crack-length-to-specimen width ratios (a/w) ranged from 0.4 to 0.7. The width-to-thickness ratio (w/B) was 1.45 or 2. The bar specimens had a height-to-width ratio of 0.435 or 0.5. Finite-element models were composed of singularity elements around the crack front and 8-noded isoparametric elements elsewhere. The models had about 11,000 degrees of freedom. Stress-intensity factors were calculated by using a nodal-force method for distribution along the crack front and by using a compliance method for average values. The stress intensity factors and load-line displacements are presented and compared with experimental solutions from the literature. The stress intensity factors and load-line displacements were about 2.5 and 5 percent lower than the reported experimental values, respectively.

Theoretical Manual for Analysis of Arch Dams

DTIC Science & Technology

1993-07-01

eight nodes lying on the midsurface , half-way between the corresponding surface nodes (Pawsey 1970). Each node on the midsurface has five DOF’s, three...translations in the global directions, and two rotations about two axes perpendicular to the midsurface normal (Figure 5-4). The sixth DOF, associated...Figure 5-3). The coordinates of any point within the element are described in terms of the midsurface coordinates and a vector connecting the two upper

Accuracy of Three Dimensional Solid Finite Elements

NASA Technical Reports Server (NTRS)

Case, W. R.; Vandegrift, R. E.

1984-01-01

The results of a study to determine the accuracy of the three dimensional solid elements available in NASTRAN for predicting displacements is presented. Of particular interest in the study is determining how to effectively use solid elements in analyzing thick optical mirrors, as might exist in a large telescope. Surface deformations due to thermal and gravity loading can be significant contributors to the determination of the overall optical quality of a telescope. The study investigates most of the solid elements currently available in either COSMIC or MSC NASTRAN. Error bounds as a function of mesh refinement and element aspect ratios are addressed. It is shown that the MSC solid elements are, in general, more accurate than their COSMIC NASTRAN counterparts due to the specialized numerical integration used. In addition, the MSC elements appear to be more economical to use on the DEC VAX 11/780 computer.

Implementation of the glacial rebound prestress advection correction in general-purpose finite element analysis software: Springs versus foundations

NASA Astrophysics Data System (ADS)

Schmidt, Peter; Lund, Björn; Hieronymus, Christoph

2012-03-01

When general-purpose finite element analysis software is used to model glacial isostatic adjustment (GIA), the first-order effect of prestress advection has to be accounted for by the user. We show here that the common use of elastic foundations at boundaries between materials of different densities will produce incorrect displacements, unless the boundary is perpendicular to the direction of gravity. This is due to the foundations always acting perpendicular to the surface to which they are attached, while the body force they represent always acts in the direction of gravity. If prestress advection is instead accounted for by the use of elastic spring elements in the direction of gravity, the representation will be correct. The use of springs adds a computation of the spring constants to the analysis. The spring constant for a particular node is defined by the product of the density contrast at the boundary, the gravitational acceleration, and the area supported by the node. To be consistent with the finite element formulation, the area is evaluated by integration of the nodal shape functions. We outline an algorithm for the calculation and include a Python script that integrates the shape functions over a bilinear quadrilateral element. For linear rectangular and triangular elements, the area supported by each node is equal to the element area divided the number of defining nodes, thereby simplifying the computation. This is, however, not true in the general nonrectangular case, and we demonstrate this with a simple 1-element model. The spring constant calculation is simple and performed in the preprocessing stage of the analysis. The time spent on the calculation is more than compensated for by a shorter analysis time, compared to that for a model with foundations. We illustrate the effects of using springs versus foundations with a simple two-dimensional GIA model of glacial loading, where the Earth model has an inclined boundary between the overlying elastic layer and the lower viscoelastic layer. Our example shows that the error introduced by the use of foundations is large enough to affect an analysis based on high-accuracy geodetic data.

Peregrine Job Queues and Scheduling Policies | High-Performance Computing |

Science.gov Websites

batch batch-h long bigmem data-transfer feature Max wall time 1 hour 4 hours 2 days 2 days 10 days 10 # nodes per job 2 8 288 576 120 46 1 # of 24 core 64 GB Haswell nodes 2 8 0 1228 0 0 0 haswell # of 24core 32 GB nodes 2 16 576 0 126 0 0 24core # of 16core 32 GB nodes 2 8 195 0 162 0 5 16core, # of 24core

Critical temperatures of hybrid laminates using finite elements

NASA Astrophysics Data System (ADS)

Chockalingam, S.; Mathew, T. C.; Singh, G.; Rao, G. V.

1992-06-01

Thermal buckling of antisymmetric cross-ply hybrid laminates is investigated. A one-dimensional finite element based on first-order shear deformation theory, having two nodes and six degrees of freedom per node, namely axial displacement, transverse displacements and rotation of the normal to the beam axis and their derivatives with respect to beam coordinate axis, is employed for this purpose. Various types of hybrid laminates with different combination of glass/epoxy, Kevlar/epoxy and carbon/epoxy are considered. Effects of slenderness ratio, boundary conditions and lay-ups are studied in detail.

A New Finite Element Supersonic Kernel Function Method in Lifting Surface Theory. Volume 2. User’s Manual

DTIC Science & Technology

1976-04-01

node. A schematic flow chart of the program is shown i& Fig. 1. Description of Variables BETA COEF IANGLE 1BUF ICHECK IMAX INFO JMAX KMAX ß...MAXINT DEL IMAX JMAX XLAMDA NMODE NP NELEM ICHECK Mach number Reduced frequency Mesh spacing as measured by the length of the side of the...Number of nodes Number of elements Option parameter used to check the mesh correctness. For ICHECK = 1, a quick run is performed to print out the

WARP3D-Release 10.8: Dynamic Nonlinear Analysis of Solids using a Preconditioned Conjugate Gradient Software Architecture

NASA Technical Reports Server (NTRS)

Koppenhoefer, Kyle C.; Gullerud, Arne S.; Ruggieri, Claudio; Dodds, Robert H., Jr.; Healy, Brian E.

1998-01-01

This report describes theoretical background material and commands necessary to use the WARP3D finite element code. WARP3D is under continuing development as a research code for the solution of very large-scale, 3-D solid models subjected to static and dynamic loads. Specific features in the code oriented toward the investigation of ductile fracture in metals include a robust finite strain formulation, a general J-integral computation facility (with inertia, face loading), an element extinction facility to model crack growth, nonlinear material models including viscoplastic effects, and the Gurson-Tver-gaard dilatant plasticity model for void growth. The nonlinear, dynamic equilibrium equations are solved using an incremental-iterative, implicit formulation with full Newton iterations to eliminate residual nodal forces. The history integration of the nonlinear equations of motion is accomplished with Newmarks Beta method. A central feature of WARP3D involves the use of a linear-preconditioned conjugate gradient (LPCG) solver implemented in an element-by-element format to replace a conventional direct linear equation solver. This software architecture dramatically reduces both the memory requirements and CPU time for very large, nonlinear solid models since formation of the assembled (dynamic) stiffness matrix is avoided. Analyses thus exhibit the numerical stability for large time (load) steps provided by the implicit formulation coupled with the low memory requirements characteristic of an explicit code. In addition to the much lower memory requirements of the LPCG solver, the CPU time required for solution of the linear equations during each Newton iteration is generally one-half or less of the CPU time required for a traditional direct solver. All other computational aspects of the code (element stiffnesses, element strains, stress updating, element internal forces) are implemented in the element-by- element, blocked architecture. This greatly improves vectorization of the code on uni-processor hardware and enables straightforward parallel-vector processing of element blocks on multi-processor hardware.

Ultrascalable petaflop parallel supercomputer

DOEpatents

Blumrich, Matthias A [Ridgefield, CT; Chen, Dong [Croton On Hudson, NY; Chiu, George [Cross River, NY; Cipolla, Thomas M [Katonah, NY; Coteus, Paul W [Yorktown Heights, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Hall, Shawn [Pleasantville, NY; Haring, Rudolf A [Cortlandt Manor, NY; Heidelberger, Philip [Cortlandt Manor, NY; Kopcsay, Gerard V [Yorktown Heights, NY; Ohmacht, Martin [Yorktown Heights, NY; Salapura, Valentina [Chappaqua, NY; Sugavanam, Krishnan [Mahopac, NY; Takken, Todd [Brewster, NY

2010-07-20

A massively parallel supercomputer of petaOPS-scale includes node architectures based upon System-On-a-Chip technology, where each processing node comprises a single Application Specific Integrated Circuit (ASIC) having up to four processing elements. The ASIC nodes are interconnected by multiple independent networks that optimally maximize the throughput of packet communications between nodes with minimal latency. The multiple networks may include three high-speed networks for parallel algorithm message passing including a Torus, collective network, and a Global Asynchronous network that provides global barrier and notification functions. These multiple independent networks may be collaboratively or independently utilized according to the needs or phases of an algorithm for optimizing algorithm processing performance. The use of a DMA engine is provided to facilitate message passing among the nodes without the expenditure of processing resources at the node.

Determinations of rare earth element abundance and U-Pb age of zircons using multispot laser ablation-inductively coupled plasma mass spectrometry.

PubMed

Yokoyama, Takaomi D; Suzuki, Toshihiro; Kon, Yoshiaki; Hirata, Takafumi

2011-12-01

We have developed a new calibration technique for multielement determination and U-Pb dating of zircon samples using laser ablation-inductively coupled plasma mass spectrometry (ICPMS) coupled with galvanometric optics. With the galvanometric optics, laser ablation of two or more sample materials could be achieved in very short time intervals (~10 ms). The resulting sample aerosols released from different ablation pits or different solid samples were mixed and homogenized within the sample cell and then transported into the ICP ion source. Multiple spot laser ablation enables spiking of analytes or internal standard elements directly into the solid samples, and therefore the standard addition calibration method can be applied for the determination of trace elements in solid samples. In this study, we have measured the rare earth element (REE) abundances of two zircon samples (Nancy 91500 and Prešovice) based on the standard addition technique, using a direct spiking of analytes through a multispot laser ablation of the glass standard material (NIST SRM612). The resulting REE abundance data show good agreement with previously reported values within analytical uncertainties achieved in this study (10% for most elements). Our experiments demonstrated that nonspectroscopic interferences on 14 REEs could be significantly reduced by the standard addition technique employed here. Another advantage of galvanometric devices is the accumulation of sample aerosol released from multiple spots. In this study we have measured the U-Pb age of a zircon sample (LMR) using an accumulation of sample aerosols released from 10 separate ablation pits of low diameters (~8 μm). The resulting (238)U-(206)Pb age data for the LMR zircons was 369 ± 64 Ma, which is in good agreement with previously reported age data (367.6 ± 1.5 Ma). (1) The data obtained here clearly demonstrate that the multiple spot laser ablation-ICPMS technique can become a powerful approach for elemental and isotopic ratio measurements in solid materials.

Determining Diagonal Branches in Mine Ventilation Networks

NASA Astrophysics Data System (ADS)

Krach, Andrzej

2014-12-01

The present paper discusses determining diagonal branches in a mine ventilation network by means of a method based on the relationship A⊗ PT(k, l) = M, which states that the nodal-branch incidence matrix A, modulo-2 multiplied by the transposed path matrix PT(k, l ) from node no. k to node no. l, yields the matrix M where all the elements in rows k and l - corresponding to the start and the end node - are 1, and where the elements in the remaining rows are 0, exclusively. If a row of the matrix M is to contain only "0" elements, the following condition has to be fulfilled: after multiplying the elements of a row of the matrix A by the elements of a column of the matrix PT(k, l), i.e. by the elements of a proper row of the matrix P(k, l ), the result row must display only "0" elements or an even number of "1" entries, as only such a number of "1" entries yields 0 when modulo-2 added - and since the rows of the matrix A correspond to the graph nodes, and the path nodes level is 2 (apart from the nodes k and l, whose level is 1), then the number of "1" elements in a row has to be 0 or 2. If, in turn, the rows k and l of the matrix M are to contain only "1" elements, the following condition has to be fulfilled: after multiplying the elements of the row k or l of the matrix A by the elements of a column of the matrix PT(k, l), the result row must display an uneven number of "1" entries, as only such a number of "1" entries yields 1 when modulo-2 added - and since the rows of the matrix A correspond to the graph nodes, and the level of the i and j path nodes is 1, then the number of "1" elements in a row has to be 1. The process of determining diagonal branches by means of this method was demonstrated using the example of a simple ventilation network with two upcast shafts and one downcast shaft. W artykule przedstawiono metodę wyznaczania bocznic przekątnych w sieci wentylacyjnej kopalni metodą bazującą na zależności A⊗PT(k, l) = M, która podaje, że macierz incydencji węzłowo bocznicowej A pomnożona modulo 2 przez transponowaną macierz ścieżek PT(k, l) od węzła nr k do węzła nr l daje w wyniku macierz M o takich własnościach że ma same jedynki w wierszach k i l, odpowiadającym węzłom początkowemu i końcowemu i same zera w pozostałych wierszach. Warunkiem na to, aby w wierszu macierzy M były same zera jest aby po pomnożeniu elementów wiersza macierzy A przez elementy kolumny macierzy PT(k, l), czyli przez elementy odpowiedniego wiersza macierzy P(k, l), w wierszu wynikowym były same zera lub parzysta liczba jedynek, ponieważ tylko taka liczba jedynek zsumowana modulo 2 daje w wyniku 0, a ponieważ wiersze macierzy A odpowiadają węzłom grafu, a węzły ścieżki są stopnia 2 (oprócz węzłów k i l, które są stopnia 1), to liczba jedynek w wierszu musi być równa 0 lub 2. Natomiast warunkiem na to, aby w wierszach k i l macierzy M były same jedynki jest aby po pomnożeniu elementów wiersza k lub l macierzy A przez elementy kolumny macierzy PT(k, l) w wierszu wynikowym była nieparzysta liczba jedynek, ponieważ tylko taka liczba jedynek zsumowana modulo 2 daje w wyniku 1, a ponieważ wiersze macierzy A odpowiadają węzłom grafu, a węzły k i j ścieżki są stopnia 1, to liczba jedynek w wierszu musi być równa 1. Wyznaczanie bocznic przekątnych tą metodą pokazano na przykładzie prostej sieci wentylacyjnej z dwoma szybami wydechowymi i jednym wdechowym.

Smart Sensor Network for Aircraft Corrosion Monitoring

DTIC Science & Technology

2010-02-01

Network Elements – Hub, Network capable application processor ( NCAP ) – Node, Smart transducer interface module (STIM)  Corrosion Sensing and...software Transducer software Network Protocol 1451.2 1451.3 1451.5 1451.6 1451.7 I/O Node -processor Power TEDS Smart Sensor Hub ( NCAP ) IEEE 1451.0 and

Coupled mixed-field laminate theory and finite element for smart piezoelectric composite shell structures

NASA Technical Reports Server (NTRS)

Saravanos, Dimitris A.

1996-01-01

Mechanics for the analysis of laminated composite shells with piezoelectric actuators and sensors are presented. A new mixed-field laminate theory for piezoelectric shells is formulated in curvilinear coordinates which combines single-layer assumptions for the displacements and a layerwise representation for the electric potential. The resultant coupled governing equations for curvilinear piezoelectric laminates are described. Structural mechanics are subsequently developed and an 8-node finite-element is formulated for the static and dynamic analysis of adaptive composite structures of general laminations containing piezoelectric layers. Evaluations of the method and comparisons with reported results are presented for laminated piezoelectric-composite plates, a closed cylindrical shell with a continuous piezoceramic layer and a laminated composite semi-circular cantilever shell with discrete cylindrical piezoelectric actuators and/or sensors.

Network testbed creation and validation

DOEpatents

Thai, Tan Q.; Urias, Vincent; Van Leeuwen, Brian P.; Watts, Kristopher K.; Sweeney, Andrew John

2017-03-21

Embodiments of network testbed creation and validation processes are described herein. A "network testbed" is a replicated environment used to validate a target network or an aspect of its design. Embodiments describe a network testbed that comprises virtual testbed nodes executed via a plurality of physical infrastructure nodes. The virtual testbed nodes utilize these hardware resources as a network "fabric," thereby enabling rapid configuration and reconfiguration of the virtual testbed nodes without requiring reconfiguration of the physical infrastructure nodes. Thus, in contrast to prior art solutions which require a tester manually build an emulated environment of physically connected network devices, embodiments receive or derive a target network description and build out a replica of this description using virtual testbed nodes executed via the physical infrastructure nodes. This process allows for the creation of very large (e.g., tens of thousands of network elements) and/or very topologically complex test networks.

Network testbed creation and validation

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

Thai, Tan Q.; Urias, Vincent; Van Leeuwen, Brian P.

Embodiments of network testbed creation and validation processes are described herein. A "network testbed" is a replicated environment used to validate a target network or an aspect of its design. Embodiments describe a network testbed that comprises virtual testbed nodes executed via a plurality of physical infrastructure nodes. The virtual testbed nodes utilize these hardware resources as a network "fabric," thereby enabling rapid configuration and reconfiguration of the virtual testbed nodes without requiring reconfiguration of the physical infrastructure nodes. Thus, in contrast to prior art solutions which require a tester manually build an emulated environment of physically connected network devices,more » embodiments receive or derive a target network description and build out a replica of this description using virtual testbed nodes executed via the physical infrastructure nodes. This process allows for the creation of very large (e.g., tens of thousands of network elements) and/or very topologically complex test networks.« less

[Changes of heart electrophysiological parameters after destruction of epicardial subplexuses that innervate sinoatrial node].

PubMed

Kulboka, Arūnas; Veikutis, Vincentas; Pauza, Dainius Haroldas; Lekas, Raimundas

2003-01-01

The aims of present study were to verify the topography of the intracardiac nerve subplexuses (INS) by using electrophysiological methods, its relations with sinoatrial (SA) node function and to investigate possibility of selective surgical SA node denervation. Fifteen mongrel dogs of either sex weighing 8 to 15 kg were used for electrophysiological studies. Both cervical vagosympathetic trunks were isolated and crushed by tight ligatures. Nervus subplexuses destructions were performed by cryocoagulation in three zones located around the right superior vena cava: ventral, lateral and dorsal. The sinus rhythm, SA node function recovery time, AV node conductivity, AV node and atrial effective refractory period were measured. Five experiments in each of three zones were performed. Experimental data show that destruction of the epicardial nerves has different effect on electrophysiological parameters. After destruction of the anterior zone of the right atrium the sinus rhythm decreased on an average by 11.6%; SA node function recovery time prolonged by 7.2%; AV node conductivity decreased by 13.1%; AV node effective refractory period prolonged by 12.9% and atrial effective refractory period, by 10.9 %. Measurements of electrophysiological parameters after intravenous injection of atropine sulphate show that sinus rhythm decreased on an average by 23.4%; SA node function recovery time increased by 9.1%; the conductivity of AV node decreased by 10.2%; AV node effective refractory period prolonged by 15.4% and atrial effective refractory period, by 13.2%. After destruction of the intracardiac nerves of the lateral zone, the sinus rhythm decreased by 15.7%; SA node function recovery time increased by 16.3%; AV node conductivity decreased by 8.3%; AV node effective refractory period and atrial effective refractory period prolonged by 11.9% and 10.0%, respectively. After the atropine sulphate intravenous injection, the sinus rhythm decreased on an average by 7.1%, SA node function recovery time prolonged by 7.1%, AV conductivity decreased by 9.1%, AV node effective refractory period increased by 12.4%, and atrial effective refractory period prolonged by 12.5%. After destruction of the nerves in the dorsal zone the changes of electrophysiological parameters were opposite to those obtained after destruction of the nerve tracts in the anterior or lateral zones: the sinus rhythm increased on an average by 4.3%; SA node function recovery time shortened by 8.8%; AV conductivity increased by 9.7%; AV node and atrial effective refractory period decreased by 12.3% and 12.1%, respectively. After intravenous atropine sulphate infusion, sinus rhythm decreased on an average by 8.3%; SA node function recovery time prolonged by 9.6%; AV node conductivity decreased by 5%; AV node and atrial effective refractory period prolonged by 4.2% and 5.2%, respectively. The average changes of electrophysiological parameters before and after INS destruction shows that cryocoagulation of ventral and lateral zones eliminates the effects of sympathetic tone to SA and AV nodal activity. Cryocoagulation of dorsal zone eliminates the effects of nervus vagus to both nodal structures. These findings shows the possibility alter or correct SA node function by making selective surgical SA node denervation.

Efficient finite element modelling for the investigation of the dynamic behaviour of a structure with bolted joints

NASA Astrophysics Data System (ADS)

Omar, R.; Rani, M. N. Abdul; Yunus, M. A.; Mirza, W. I. I. Wan Iskandar; Zin, M. S. Mohd

2018-04-01

A simple structure with bolted joints consists of the structural components, bolts and nuts. There are several methods to model the structures with bolted joints, however there is no reliable, efficient and economic modelling methods that can accurately predict its dynamics behaviour. Explained in this paper is an investigation that was conducted to obtain an appropriate modelling method for bolted joints. This was carried out by evaluating four different finite element (FE) models of the assembled plates and bolts namely the solid plates-bolts model, plates without bolt model, hybrid plates-bolts model and simplified plates-bolts model. FE modal analysis was conducted for all four initial FE models of the bolted joints. Results of the FE modal analysis were compared with the experimental modal analysis (EMA) results. EMA was performed to extract the natural frequencies and mode shapes of the test physical structure with bolted joints. Evaluation was made by comparing the number of nodes, number of elements, elapsed computer processing unit (CPU) time, and the total percentage of errors of each initial FE model when compared with EMA result. The evaluation showed that the simplified plates-bolts model could most accurately predict the dynamic behaviour of the structure with bolted joints. This study proved that the reliable, efficient and economic modelling of bolted joints, mainly the representation of the bolting, has played a crucial element in ensuring the accuracy of the dynamic behaviour prediction.

Application of alkaline solid residue of electric arc furnace dust for neutralization/purification of electroplating wastewaters.

PubMed

Elez, Loris; Orescanin, Visnja; Sofilic, Tahir; Mikulic, Nenad; Ruk, Damir

2008-10-01

The purpose of this work was development of an appropriate procedure for the neutralization/purification of electroplating wastewater (EWW) with alkaline solid residue (ASR) by-product of the alkaline extraction of zinc and lead from electric arc furnace dust (EAFD). Removal efficiency of ASR at optimum purification conditions (pH 8 and mixing time; 20 minutes) for the elements Pb, Cr (VI), Cr (III), Fe, Ni, Cu and Zn were 94.92%, 97.58%, 99.59%, 99.48%, 97.25% and 99.97%, respectively. The concentrations of all elements in the purified wastewater were significantly lower in relation to the upper permissible limit for wastewaters suitable for discharge into the environment. The remaining waste mud was regenerated in the strong alkaline medium and successfully applied once again for the neutralization/purification of EWW. Removal efficiencies of heavy metals accomplished with regenerated waste mud were comparable to these achieved by original ASR. Elemental concentrations in the leachates of the waste mud were in accordance with regulated values.

Compacting biomass waste materials for use as fuel

NASA Astrophysics Data System (ADS)

Zhang, Ou

Every year, biomass waste materials are produced in large quantity. The combustibles in biomass waste materials make up over 70% of the total waste. How to utilize these waste materials is important to the nation and the world. The purpose of this study is to test optimum processes and conditions of compacting a number of biomass waste materials to form a densified solid fuel for use at coal-fired power plants or ordinary commercial furnaces. Successful use of such fuel as a substitute for or in cofiring with coal not only solves a solid waste disposal problem but also reduces the release of some gases from burning coal which cause health problem, acid rain and global warming. The unique punch-and-die process developed at the Capsule Pipeline Research Center, University of Missouri-Columbia was used for compacting the solid wastes, including waste paper, plastics (both film and hard products), textiles, leaves, and wood. The compaction was performed to produce strong compacts (biomass logs) under room temperature without binder and without preheating. The compaction conditions important to the commercial production of densified biomass fuel logs, including compaction pressure, pressure holding time, back pressure, moisture content, particle size, binder effects, and mold conditions were studied and optimized. The properties of the biomass logs were evaluated in terms of physical, mechanical, and combustion characteristics. It was found that the compaction pressure and the initial moisture content of the biomass material play critical roles in producing high-quality biomass logs. Under optimized compaction conditions, biomass waste materials can be compacted into high-quality logs with a density of 0.8 to 1.2 g/cm3. The logs made from the combustible wastes have a heating value in the range 6,000 to 8,000 Btu/lb which is only slightly (10 to 30%) less than that of subbituminous coal. To evaluate the feasibility of cofiring biomass logs with coal, burn tests were conducted in a stoke boiler. A separate burning test was also carried out by burning biomass logs alone in an outdoor hot-water furnace for heating a building. Based on a previous coal compaction study, the process of biomass compaction was studied numerically by use of a non-linear finite element code. A constitutive model with sufficient generality was adapted for biomass material to deal with pore contraction during compaction. A contact node algorithm was applied to implement the effect of mold wall friction into the finite element program. Numerical analyses were made to investigate the pressure distribution in a die normal to the axis of compaction, and to investigate the density distribution in a biomass log after compaction. The results of the analyses gave generally good agreement with theoretical analysis of coal log compaction, although assumptions had to be made about the variation in the elastic modulus of the material and the Poisson's ratio during the compaction cycle.

Improving Biomethane Production and Mass Bioconversion of Corn Stover Anaerobic Digestion by Adding NaOH Pretreatment and Trace Elements

PubMed Central

Liu, ChunMei; Yuan, HaiRong; Zou, DeXun; Liu, YanPing; Zhu, BaoNing; Li, XiuJin

2015-01-01

This research applied sodium hydroxide (NaOH) pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mg·L−1·d−1 of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%–62.2% higher than with NaOH-pretreatment alone and 22.2%–56.3% higher than with untreated corn stover. The best combination was obtained 5–9 days shorter than T90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production. PMID:26137469

Role of the node in controlling traffic of cadmium, zinc, and manganese in rice

PubMed Central

Yamaguchi, Noriko; Ishikawa, Satoru; Abe, Tadashi; Baba, Koji; Terada, Yasuko

2012-01-01

Heavy metals are transported to rice grains via the phloem. In rice nodes, the diffuse vascular bundles (DVBs), which enclose the enlarged elliptical vascular bundles (EVBs), are connected to the panicle and have a morphological feature that facilitates xylem-to-phloem transfer. To find a mechanism for restricting cadmium (Cd) transport into grains, the distribution of Cd, zinc (Zn), manganese (Mn), and sulphur (S) around the vascular bundles in node I (the node beneath the panicle) of Oryza sativa ‘Koshihikari’ were compared 1 week after heading. Elemental maps of Cd, Zn, Mn, and S in the vascular bundles of node I were obtained by synchrotron micro-X-ray fluorescence spectrometry and electron probe microanalysis. In addition, Cd K-edge microfocused X-ray absorption near-edge structure analyses were used to identify the elements co-ordinated with Cd. Both Cd and S were mainly distributed in the xylem of the EVB and in the parenchyma cell bridge (PCB) surrounding the EVB. Zn accumulated in the PCB, and Mn accumulated around the protoxylem of the EVB. Cd was co-ordinated mainly with S in the xylem of the EVB, but with both S and O in the phloem of the EVB and in the PCB. The EVB in the node retarded horizontal transport of Cd toward the DVB. By contrast, Zn was first stored in the PCB and then efficiently transferred toward the DVB. Our results provide evidence that transport of Cd, Zn, and Mn is differentially controlled in rice nodes, where vascular bundles are functionally interconnected. PMID:22291135

A Sensemaking Approach to Visual Analytics of Attribute-Rich Social Networks

ERIC Educational Resources Information Center

Gou, Liang

2012-01-01

Social networks have become more complex, in particular considering the fact that elements in social networks are not only abstract topological nodes and links, but contain rich social attributes and reflecting diverse social relationships. For example, in a co-authorship social network in a scientific community, nodes in the social network, which…

Innovative Solid State Infrared Laser Devices

DTIC Science & Technology

2010-12-01

The polycrystalline, 8.9x7.0x3.0 mm3 (LxWxH) Cr2+:ZnSe gain element was installed at the Brewster angle of 67.7º for horizontal polarization...8 3.1.4 Waveguide devices for thermal lensing mitigation ................................... 10...power of Cr2+:ZnSe, modelocked operation of Cr2+:ZnSe and suppression of thermal lensing effects. 3.1.1 Cr2+:ZnSe power scaling We achieved first

An Analysis of the Centaur Ground Processing System at the Kennedy Space Center/Cape Canaveral AFS.

DTIC Science & Technology

1985-12-01

SPONSORING 8tn OFF ICE SYMBOL 9 . PROCUREMENT INSTRUMENT IDENTIFiCATION NUMBER 0 RG4NICATICN II appsicable, * cADDRESS C-;t,. S:sI. and~ /11’ L,a,, .0...The PERT Network................8 2. The SLAM Model................. 9 F. Outline of the Paper................13 Ii. The Shuttle/Centaur G System...104 9 . AWAIT NODE..................104 10. FREE NODE...................105 11. ASSIGN NODE..................105 w 12. COLCT NODE

A Viscoelastic Hybrid Shell Finite Element

NASA Technical Reports Server (NTRS)

Johnson, Arthur

1999-01-01

An elastic large displacement thick-shell hybrid finite element is modified to allow for the calculation of viscoelastic stresses. Internal strain variables are introduced at he element's stress nodes and are employed to construct a viscous material model. First order ordinary differential equations relate the internal strain variables to the corresponding elastic strains at the stress nodes. The viscous stresses are computed from the internal strain variables using viscous moduli which are a fraction of the elastic moduli. The energy dissipated by the action of the viscous stresses in included in the mixed variational functional. Nonlinear quasi-static viscous equilibrium equations are then obtained. Previously developed Taylor expansions of the equilibrium equations are modified to include the viscous terms. A predictor-corrector time marching solution algorithm is employed to solve the algebraic-differential equations. The viscous shell element is employed to numerically simulate a stair-step loading and unloading of an aircraft tire in contact with a frictionless surface.

Development of Bread Board Model of TRMM precipitation radar

NASA Astrophysics Data System (ADS)

Okamoto, Ken'ichi; Ihara, Toshio; Kumagai, Hiroshi

The active array radar was selected as a reliable candidate for the TRMM (Tropical Rainfall Measuring Mission) precipitation radar after the trade off studies performed by Communications Research Laboratory (CRL) in the US-Japan joint feasibility study of TRMM in 1987-1988. Main system parameters and block diagram for TRMM precipitation radar are shown as the result of feasibility study. CRL developed key devices for the active array precipitation radar such as 8-element slotted waveguide array antenna, the 5 bit PIN diode phase shifters, solid state power amplifiers and low noise amplifiers in 1988-1990. Integration of these key devices was made to compose 8-element Bread Board Model of TRMM precipitation radar.

Solid Phase Extraction of Trace Elements in Waterand Tissue Samples on a Mini Column with Diphenylcarbazone Impregnated Nano-TiO2 and Their Determination by Inductively Coupled Plasma Optical Emission Spectrometry

PubMed Central

Baytak, Sıtkı; Arslan, Zikri

2015-01-01

This study presents a simple, robust and environmentally friendly solid phase preconcentration procedure for multielement determination by inductively coupled plasma optical emission spectrometry (ICP-OES) using diphenylcarbazone (DPC) impregnated TiO2 nanopowder (n-TiO2). DPC was successfully impregnated onto n-TiO2 in colloidal solution. A number of elements, including Co(II), Cr(III), Cu(II), Fe(III), Mn(II) and Zn(II) were quantitatively preconcentrated from aqueous solutions between pH 8 and 8.5 at a flow rate of 2 mL min−1, and then eluted with 2 mL of 5% (v/v) HNO3. A mini-column packed with 0.12 g DPC impregnated n-TiO2 retained all elements quantitatively from up to 250 mL multielement solution (2.5 μg per analyte) affording an enrichment factor of 125. The limits of detection (LOD) for preconcentration of 50 mL blank solutions (n = 12) were 0.28, 0.15, 0.25, 0.22, 0.12, and 0.10 μg L−1 for Co, Cr, Cu, Fe, Mn, and Zn, respectively. The relative standard deviation (RSD) for five replicate determinations was 0.8, 3.4, 2.6, 2.2, 1.2 and 3.3% for Co, Cr, Cu, Fe, Mn and Zn, respectively, at 5 μg L−1 level. The method was validated with analysis of Freshwater (SRM 1643e) and Lobster hepatopancreas (TORT-2) certified reference materials, and then applied to the determination of the elements from tap water and lake water samples by ICP-OES. PMID:26236403

Node property of weighted networks considering connectability to nodes within two degrees of separation.

PubMed

Amano, Sun-Ichi; Ogawa, Ken-Ichiro; Miyake, Yoshihiro

2018-05-31

Weighted networks have been extensively studied because they can represent various phenomena in which the diversity of edges is essential. To investigate the properties of weighted networks, various centrality measures have been proposed, such as strength, weighted clustering coefficients, and weighted betweenness centrality. In such measures, only direct connections or entire network connectivity from arbitrary nodes have been used to calculate the connectivity of each node. However, in weighted networks composed of autonomous elements such as humans, middle ranges from each node are also considered to be meaningful for characterizing each node's connectability. In this study, we define a new node property in weighted networks to consider connectability to nodes within a range of two degrees of separation, then apply this new centrality to face-to-face human communication networks in corporate organizations. Our results show that the proposed centrality distinguishes inherent communities corresponding to the job types in each organization with a high degree of accuracy. This indicates the possibility that connectability to nodes within two degrees of separation reveals potential trends of weighted networks that are not apparent from conventional measures.

Rigid body formulation in a finite element context with contact interaction

NASA Astrophysics Data System (ADS)

Refachinho de Campos, Paulo R.; Gay Neto, Alfredo

2018-03-01

The present work proposes a formulation to employ rigid bodies together with flexible bodies in the context of a nonlinear finite element solver, with contact interactions. Inertial contributions due to distribution of mass of a rigid body are fully developed, considering a general pole position associated with a single node, representing a rigid body element. Additionally, a mechanical constraint is proposed to connect a rigid region composed by several nodes, which is useful for linking rigid/flexible bodies in a finite element environment. Rodrigues rotation parameters are used to describe finite rotations, by an updated Lagrangian description. In addition, the contact formulation entitled master-surface to master-surface is employed in conjunction with the rigid body element and flexible bodies, aiming to consider their interaction in a rigid-flexible multibody environment. New surface parameterizations are presented to establish contact pairs, permitting pointwise interaction in a frictional scenario. Numerical examples are provided to show robustness and applicability of the methods.

[The validity of the sentinel node concept in gastrointestinal cancers].

PubMed

Kitagawa, Y; Fujii, H; Mukai, M; Ando, N; Kubota, T; Ikeda, T; Ohgami, M; Watanabe, M; Otani, Y; Ozawa, S; Hasegawa, H; Furukawa, T; Nakahara, T; Kubo, A; Kumai, K; Kitajima, M

2000-03-01

Although the sentinel node concept has been validated and clinically applied to breast cancer and malignant melanoma, its clinical significance in other solid tumors has not been thoroughly investigated. With regard to gastrointestinal (GI) cancers in particular, our surgeons have been cautious because of the high frequency of skip metastasis and the complicated lymphatic system in the GI tract. We would like to emphasize that so-called skip metastasis has been defined according to anatomic classification of regional lymph nodes and that the lymphatic drainage route must be patient or lesion specific. To test the validity and feasibility of this concept in GI cancers, we have established a radio-guided intraoperative sentinel node navigation system using preoperative endoscopic submucosal injection of radioactive tracer followed by intra-operative gamma-probing. In 131 patients with GI cancers (esophagus: 22, stomach: 71, colorectum: 38), the detection rate of sentinel nades was 91% and overall diagnostic accuracy of lymph node metastasis by sentinel node status was 97%. Initial results suggest further investigation of this procedure as an accurate staging and a minimally invasive approach to early GI cancers.

Defect energetics of concentrated solid-solution alloys from ab initio calculations: Ni 0.5Co 0.5, Ni 0.5Fe 0.5, Ni 0.8Fe 0.2 and Ni 0.8Cr 0.2

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

Zhao, Shijun; Stocks, George Malcolm; Zhang, Yanwen

2016-08-03

It has been shown that concentrated solid solution alloys possess unusual electronic, magnetic, transport, mechanical and radiation-resistant properties that are directly related to underlying chemical complexity. Because every atom experiences a different local atomic environment, the formation and migration energies of vacancies and interstitials in these alloys exhibit a distribution, rather than a single value as in a pure metal or dilute alloy. In this study, using ab initio calculations based on density functional theory and special quasirandom structure, we have characterized the distribution of defect formation energy and migration barrier in four Ni-based solid-solution alloys: Ni 0.5Co 0.5, Nimore » 0.5Fe 0.5, Ni 0.8Fe 0.2 and Ni 0.8Cr 0.2. As defect formation energies in finite-size models depend sensitively on the elemental chemical potential, we have developed a computationally efficient method for determining it which takes into account the global composition and the local short-range order. In addition we have compared the results of our ab initio calculations to those obtained from available embedded atom method (EAM) potentials. Our results indicate that the defect formation and migration energies are closely related to the specific atomic size in the structure, which further determines the elemental diffusion properties. In conclusion, different EAM potentials yield different features of defect energetics in concentrated alloys, pointing to the need for additional potential development efforts in order to allow spatial and temporal scale-up of defect and simulations, beyond those accessible to ab initio methods.« less

Defect energetics of concentrated solid-solution alloys from ab initio calculations: Ni0.5Co0.5, Ni0.5Fe0.5, Ni0.8Fe0.2 and Ni0.8Cr0.2.

PubMed

Zhao, Shijun; Stocks, G Malcolm; Zhang, Yanwen

2016-09-14

It has been shown that concentrated solid solution alloys possess unusual electronic, magnetic, transport, mechanical and radiation-resistant properties that are directly related to underlying chemical complexity. Because every atom experiences a different local atomic environment, the formation and migration energies of vacancies and interstitials in these alloys exhibit a distribution, rather than a single value as in a pure metal or dilute alloy. Using ab initio calculations based on density functional theory and special quasirandom structures, we have characterized the distribution of defect formation energy and migration barrier in four Ni-based solid-solution alloys: Ni0.5Co0.5, Ni0.5Fe0.5, Ni0.8Fe0.2, and Ni0.8Cr0.2. As defect formation energies in finite-size models depend sensitively on the elemental chemical potential, we have developed a computationally efficient method for determining it which takes into account the global composition and the local short-range order. In addition we have compared the results of our ab initio calculations to those obtained from available embedded atom method (EAM) potentials. Our results indicate that the defect formation and migration energies are closely related to the specific atoms in the structure, which further determines the elemental diffusion properties. Different EAM potentials yield different features of defect energetics in concentrated alloys, pointing to the need for additional potential development efforts in order to allow spatial and temporal scale-up of defect and simulations, beyond those accessible to ab initio methods.

Test-Analysis Correlation of a Crash Simulation of a Vertical Drop Test of a Commuter-Category Aircraft

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fasanella, Edwin L.

2004-01-01

A finite element model of an ATR42-300 commuter-class aircraft was developed and a crash simulation was executed. Analytical predictions were correlated with data obtained from a 30-feet per second (9.14-meters per second) vertical drop test of the aircraft. The purpose of the test was to evaluate the structural response of the aircraft when subjected to a severe, but survivable, impact. The aircraft was configured with seats, dummies, luggage, and other ballast. The wings were filled with 8,700 lb. (3,946 kilograms) of water to represent the fuel. The finite element model, which consisted of 57,643 nodes and 62,979 elements, was developed from direct measurements of the airframe geometry. The seats, dummies, luggage, simulated engines and fuel, and other ballast were represented using concentrated masses. The model was executed in LS-DYNA, a commercial finite element code for performing explicit transient dynamic simulations. Analytical predictions of structural deformation and selected time-history responses were correlated with experimental data from the drop test to validate the simulation.

Large scale cardiac modeling on the Blue Gene supercomputer.

PubMed

Reumann, Matthias; Fitch, Blake G; Rayshubskiy, Aleksandr; Keller, David U; Weiss, Daniel L; Seemann, Gunnar; Dössel, Olaf; Pitman, Michael C; Rice, John J

2008-01-01

Multi-scale, multi-physical heart models have not yet been able to include a high degree of accuracy and resolution with respect to model detail and spatial resolution due to computational limitations of current systems. We propose a framework to compute large scale cardiac models. Decomposition of anatomical data in segments to be distributed on a parallel computer is carried out by optimal recursive bisection (ORB). The algorithm takes into account a computational load parameter which has to be adjusted according to the cell models used. The diffusion term is realized by the monodomain equations. The anatomical data-set was given by both ventricles of the Visible Female data-set in a 0.2 mm resolution. Heterogeneous anisotropy was included in the computation. Model weights as input for the decomposition and load balancing were set to (a) 1 for tissue and 0 for non-tissue elements; (b) 10 for tissue and 1 for non-tissue elements. Scaling results for 512, 1024, 2048, 4096 and 8192 computational nodes were obtained for 10 ms simulation time. The simulations were carried out on an IBM Blue Gene/L parallel computer. A 1 s simulation was then carried out on 2048 nodes for the optimal model load. Load balances did not differ significantly across computational nodes even if the number of data elements distributed to each node differed greatly. Since the ORB algorithm did not take into account computational load due to communication cycles, the speedup is close to optimal for the computation time but not optimal overall due to the communication overhead. However, the simulation times were reduced form 87 minutes on 512 to 11 minutes on 8192 nodes. This work demonstrates that it is possible to run simulations of the presented detailed cardiac model within hours for the simulation of a heart beat.

Perceptual grouping effects on cursor movement expectations.

PubMed

Dorneich, Michael C; Hamblin, Christopher J; Lancaster, Jeff A; Olofinboba, Olu

2014-05-01

Two studies were conducted to develop an understanding of factors that drive user expectations when navigating between discrete elements on a display via a limited degree-of-freedom cursor control device. For the Orion Crew Exploration Vehicle spacecraft, a free-floating cursor with a graphical user interface (GUI) would require an unachievable level of accuracy due to expected acceleration and vibration conditions during dynamic phases of flight. Therefore, Orion program proposed using a "caged" cursor to "jump" from one controllable element (node) on the GUI to another. However, nodes are not likely to be arranged on a rectilinear grid, and so movements between nodes are not obvious. Proximity between nodes, direction of nodes relative to each other, and context features may all contribute to user cursor movement expectations. In an initial study, we examined user expectations based on the nodes themselves. In a second study, we examined the effect of context features on user expectations. The studies established that perceptual grouping effects influence expectations to varying degrees. Based on these results, a simple rule set was developed to support users in building a straightforward mental model that closely matches their natural expectations for cursor movement. The results will help designers of display formats take advantage of the natural context-driven cursor movement expectations of users to reduce navigation errors, increase usability, and decrease access time. The rules set and guidelines tie theory to practice and can be applied in environments where vibration or acceleration are significant, including spacecraft, aircraft, and automobiles.

A study of the impact of moist-heat and dry-heat treatment processes on hazardous trace elements migration in food waste.

PubMed

Chen, Ting; Jin, Yiying; Qiu, Xiaopeng; Chen, Xin

2015-03-01

Using laboratory experiments, the authors investigated the impact of dry-heat and moist-heat treatment processes on hazardous trace elements (As, Hg, Cd, Cr, and Pb) in food waste and explored their distribution patterns for three waste components: oil, aqueous, and solid components. The results indicated that an insignificant reduction of hazardous trace elements in heat-treated waste-0.61-14.29% after moist-heat treatment and 4.53-12.25% after dry-heat treatment-and a significant reduction in hazardous trace elements (except for Hg without external addition) after centrifugal dehydration (P < 0.5). Moreover, after heat treatment, over 90% of the hazardous trace elements in the waste were detected in the aqueous and solid components, whereas only a trace amount of hazardous trace elements was detected in the oil component (<0.01%). In addition, results indicated that heat treatment process did not significantly reduce the concentration of hazardous trace elements in food waste, but the separation process for solid and aqueous components, such as centrifugal dehydration, could reduce the risk considerably. Finally, combined with the separation technology for solid and liquid components, dry-heat treatment is superior to moist-heat treatment on the removal of external water-soluble ionic hazardous trace elements. An insignificant reduction of hazardous trace elements in heat-treated waste showed that heat treatment does not reduce trace elements contamination in food waste considerably, whereas the separation process for solid and aqueous components, such as centrifugal dehydration, could reduce the risk significantly. Moreover, combined with the separation technology for solid and liquid components, dry-heat treatment is superior to moist-heat treatment for the removal of external water-soluble ionic hazardous trace elements, by exploring distribution patterns of trace elements in three waste components: oil, aqueous, and solid components.

Crash Simulation of a Vertical Drop Test of a Commuter-Class Aircraft

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fasanella, Edwin L.

2004-01-01

A finite element model of an ATR42-300 commuter-class aircraft was developed and a crash simulation was executed. Analytical predictions were correlated with data obtained from a 30-ft/s (9.14-m/s) vertical drop test of the aircraft. The purpose of the test was to evaluate the structural response of the aircraft when subjected to a severe, but survivable, impact. The aircraft was configured with seats, dummies, luggage, and other ballast. The wings were filled with 8,700 lb. (3,946 kg) of water to represent the fuel. The finite element model, which consisted of 57,643 nodes and 62,979 elements, was developed from direct measurements of the airframe geometry. The seats, dummies, luggage, fuel, and other ballast were represented using concentrated masses. The model was executed in LS-DYNA, a commercial code for performing explicit transient dynamic simulations. Predictions of structural deformation and selected time-history responses were generated. The simulation was successfully validated through extensive test-analysis correlation.

[Characteristics of regional lymph nodes in breast cancer (quantitative histochemical study)].

PubMed

Anisimova, L O

1982-01-01

The changes in axillary lymph nodes in mammary gland carcinoma of different histological types, metastasizing and nonmetastasizing, as well as after radiation therapy and in fibroadenomatosis were studied. The study was carried out on cryostate sections by histological and histochemical methods. Signs of activation of lymph nodes were clearly seen only in solid carcinoma, not always manifested in adenocarcinomas and scirrhous carcinomas, and undetectable in fibroadenomatosis. The quantitative determination of enzymes and nucleic acids showed differences in their activity between fibroadenomatosis and carcinomas. Proliferation processes dominated significantly over lymphocyte differentiation in carcinoma, increasing even more in metastasizing tumors. Pre-operative irradiation did not inhibit metabolism or proliferative activity of the cells.

Model Checking a Self-Stabilizing Distributed Clock Synchronization Protocol for Arbitrary Digraphs

NASA Technical Reports Server (NTRS)

Malekpour, Mahyar R.

2011-01-01

This report presents the mechanical verification of a self-stabilizing distributed clock synchronization protocol for arbitrary digraphs in the absence of faults. This protocol does not rely on assumptions about the initial state of the system, other than the presence of at least one node, and no central clock or a centrally generated signal, pulse, or message is used. The system under study is an arbitrary, non-partitioned digraph ranging from fully connected to 1-connected networks of nodes while allowing for differences in the network elements. Nodes are anonymous, i.e., they do not have unique identities. There is no theoretical limit on the maximum number of participating nodes. The only constraint on the behavior of the node is that the interactions with other nodes are restricted to defined links and interfaces. This protocol deterministically converges within a time bound that is a linear function of the self-stabilization period.

Polyhedral integrated and free space optical interconnection

DOEpatents

Erteza, I.A.

1998-01-06

An optical communication system uses holographic optical elements to provide guided wave and non-guided communication, resulting in high bandwidth, high connectivity optical communications. Holograms within holographic optical elements route optical signals between elements and between nodes connected to elements. Angular and wavelength multiplexing allow the elements to provide high connectivity. The combination of guided and non-guided communication allows compact polyhedral system geometries. Guided wave communications provided by multiplexed substrate-mode holographic optical elements eases system alignment. 7 figs.

Polyhedral integrated and free space optical interconnection

DOEpatents

Erteza, Ireena A.

1998-01-01

An optical communication system uses holographic optical elements to provide guided wave and non-guided communication, resulting in high bandwidth, high connectivity optical communications. Holograms within holographic optical elements route optical signals between elements and between nodes connected to elements. Angular and wavelength multiplexing allow the elements to provide high connectivity. The combination of guided and non-guided communication allows compact polyhedral system geometries. Guided wave communications provided by multiplexed substrate-mode holographic optical elements eases system alignment.

A prototype small CdTe gamma camera for radioguided surgery and other imaging applications.

PubMed

Tsuchimochi, Makoto; Sakahara, Harumi; Hayama, Kazuhide; Funaki, Minoru; Ohno, Ryoichi; Shirahata, Takashi; Orskaug, Terje; Maehlum, Gunnar; Yoshioka, Koki; Nygard, Einar

2003-12-01

Gamma probes have been used for sentinel lymph node biopsy in melanoma and breast cancer. However, these probes can provide only radioactivity counts and variable pitch audio output based on the intensity of the detected radioactivity. We have developed a small semiconductor gamma camera (SSGC) that allows visualisation of the size, shape and location of the target tissues. This study is designed to characterise the performance of the SSGC for radioguided surgery of metastatic lesions and for other imaging applications amenable to the smaller format of this prototype imaging system. The detector head had 32 cadmium telluride semiconductor arrays with a total of 1,024 pixels, and with application-specific integrated circuits (ASICs) and a tungsten collimator. The entire assembly was encased in a lead housing measuring 152 mmx166 mmx65 mm. The effective visual field was 44.8 mmx44.8 mm. The energy resolution and imaging aspects were tested. Two spherical 5-mm- and 15-mm-diameter technetium-99m radioactive sources that had activities of 0.15 MBq and 100 MBq, respectively, were used to simulate a sentinel lymph node and an injection site. The relative detectability of these foci by the new detector and a conventional scintillation camera was studied. The prototype was also examined in a variety of clinical applications. Energy resolution [full-width at half-maximum (FWHM)] for a single element at the centre of the field of view was 4.2% at 140 keV (99mTc), and the mean energy resolution of the CdTe detector arrays was approximately 7.8%. The spatial resolution, represented by FWHM, had a mean value of 1.56 +/- 0.05 mm. Simulated node foci could be visualised clearly by the SSGC using a 15-s acquisition time. In preliminary clinical tests, the SSGC successfully imaged diseases in a variety of tissues, including salivary and thyroid glands, temporomandibular joints and sentinel lymph nodes. The SSGC has significant potential for diagnosing diseases and facilitating subsequent radioguided surgery.

Finite Element Modelling and Analysis of Damage Detection Methodology in Piezo Electric Sensor and Actuator Integrated Sandwich Cantilever Beam

NASA Astrophysics Data System (ADS)

Pradeep, K. R.; Thomas, A. M.; Basker, V. T.

2018-03-01

Structural health monitoring (SHM) is an essential component of futuristic civil, mechanical and aerospace structures. It detects the damages in system or give warning about the degradation of structure by evaluating performance parameters. This is achieved by the integration of sensors and actuators into the structure. Study of damage detection process in piezoelectric sensor and actuator integrated sandwich cantilever beam is carried out in this paper. Possible skin-core debond at the root of the cantilever beam is simulated and compared with undamaged case. The beam is actuated using piezoelectric actuators and performance differences are evaluated using Polyvinylidene fluoride (PVDF) sensors. The methodology utilized is the voltage/strain response of the damaged versus undamaged beam against transient actuation. Finite element model of piezo-beam is simulated in ANSYSTM using 8 noded coupled field element, with nodal degrees of freedoms are translations in the x, y directions and voltage. An aluminium sandwich beam with a length of 800mm, thickness of core 22.86mm and thickness of skin 0.3mm is considered. Skin-core debond is simulated in the model as unmerged nodes. Reduction in the fundamental frequency of the damaged beam is found to be negligible. But the voltage response of the PVDF sensor under transient excitation shows significantly visible change indicating the debond. Piezo electric based damage detection system is an effective tool for the damage detection of aerospace and civil structural system having inaccessible/critical locations and enables online monitoring possibilities as the power requirement is minimal.

International Space Station Environmental Control and Life Support Emergency Response Verification for Node 1

NASA Technical Reports Server (NTRS)

Williams, David E.

2008-01-01

The International Space Station (ISS) Node 1 Environmental Control and Life Support (ECLS) System is comprised of five subsystems: Atmosphere Control and Supply (ACS), Atmosphere Revitalization (AR), Fire Detection and Suppression (FDS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). This paper provides a summary of the Node 1 Emergency Response capability, which includes nominal and off-nominal FDS operation, off nominal ACS operation, and off-nominal THC operation. These subsystems provide the capability to help aid the crew members during an emergency cabin depressurization, a toxic spill, or a fire. The paper will also provide a discussion of the detailed Node 1 ECLS Element Verification methodologies for operation of the Node 1 Emergency Response hardware operations utilized during the Qualification phase.

Trace element emissions from spontaneous combustion of gob piles in coal mines, Shanxi, China

USGS Publications Warehouse

Zhao, Y.; Zhang, Jiahua; Chou, C.-L.; Li, Y.; Wang, Z.; Ge, Y.; Zheng, C.

2008-01-01

The emissions of potentially hazardous trace elements from spontaneous combustion of gob piles from coal mining in Shanxi Province, China, have been studied. More than ninety samples of solid waste from gob piles in Shanxi were collected and the contents of twenty potentially hazardous trace elements (Be, F, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Sb, Hg, Tl, Pb, Th, and U) in these samples were determined. Trace element contents in solid waste samples showed wide ranges. As compared with the upper continental crust, the solid waste samples are significantly enriched in Se (20x) and Tl (12x) and are moderately enriched in F, As, Mo, Sn, Sb, Hg, Th, and U (2-5x). The solid waste samples are depleted in V, Cr, Mn, Co, Ni, Cu, and Zn. The solid waste samples are enriched in F, V, Mn, Cr, Co, Ni, Cu, Zn, Sb, Th, and U as compared with the Shanxi coals. Most trace elements are higher in the clinker than in the unburnt solid waste except F, Sn, and Hg. Trace element abundances are related to the ash content and composition of the samples. The content of F is negatively correlated with the ash content, while Pb is positively correlated with the ash. The concentrations of As, Mn, Zn, and Cd are highly positively correlated with Fe2O3 in the solid waste. The As content increases with increasing sulfur content in the solid waste. The trace element emissions are calculated for mass balance. The emission factors of trace elements during the spontaneous combustion of the gobs are determined and the trace element concentrations in the flue gas from the spontaneous combustion of solid waste are calculated. More than a half of F, Se, Hg and Pb are released to the atmosphere during spontaneous combustion. Some trace element concentrations in flue gas are higher than the national emission standards. Thus, gob piles from coal mining pose a serious environmental problem. ?? 2007 Elsevier B.V. All rights reserved.

Evaluation of Acoustic Propagation Paths into the Human Head

DTIC Science & Technology

2005-07-25

paths. A 3D finite-element solid mesh was constructed using a digital image database of an adult male head. Finite-element analysis was used to model the...air-borne sound pressure amplitude) via the alternate propagation paths. A 3D finite-element solid mesh was constructed using a digital image database ... database of an adult male head Coupled acoustic-mechanical finite-element analysis (FEA) was used to model the wave propagation through the fluid-solid

A computerized symbolic integration technique for development of triangular and quadrilateral composite shallow-shell finite elements

NASA Technical Reports Server (NTRS)

Anderson, C. M.; Noor, A. K.

1975-01-01

Computerized symbolic integration was used in conjunction with group-theoretic techniques to obtain analytic expressions for the stiffness, geometric stiffness, consistent mass, and consistent load matrices of composite shallow shell structural elements. The elements are shear flexible and have variable curvature. A stiffness (displacement) formulation was used with the fundamental unknowns consisting of both the displacement and rotation components of the reference surface of the shell. The triangular elements have six and ten nodes; the quadrilateral elements have four and eight nodes and can have internal degrees of freedom associated with displacement modes which vanish along the edges of the element (bubble modes). The stiffness, geometric stiffness, consistent mass, and consistent load coefficients are expressed as linear combinations of integrals (over the element domain) whose integrands are products of shape functions and their derivatives. The evaluation of the elemental matrices is divided into two separate problems - determination of the coefficients in the linear combination and evaluation of the integrals. The integrals are performed symbolically by using the symbolic-and-algebraic-manipulation language MACSYMA. The efficiency of using symbolic integration in the element development is demonstrated by comparing the number of floating-point arithmetic operations required in this approach with those required by a commonly used numerical quadrature technique.

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

Agnew, Douglas W.; Gembicky, Milan; Moore, Curtis E.

Here, the preparation of 3D and 2D Cu(I) coordination networks using ditopic m-terphenyl isocyanides is described. The incorporation of sterically encumbering substituents enables the controlled, solid-state preparation of Cu(I) tris-isocyanide nodes with a labile solvent ligand in a manner mirroring solution-phase chemistry of monomeric complexes. The protection afforded by the m-terphenyl groups is also shown to engender significant stability towards heat as well as acidic or basic conditions, resulting in robust single-metal-node networks that can transition from 3D to 2D extended structures.

Up-conversion media on basis single crystals BaY2F8 for UV and VUV solid state lasers

NASA Astrophysics Data System (ADS)

Pushkar, A. A.; Ouvarova, T. V.; Molchanov, V. N.

2007-04-01

Crystal BaY IIF 8 represents the big interest as the perspective active media for lasers ultra-violet (UV) and vacuumultra- violet (VUV) regions. For the decision of problems with solarization this media and a choice of sources pump it is offered to use up-conversion mechanisms pump with activators from rare-earth elements (RE). We have developed technology of grown of oriented monocrystals BaY IIF 8, have defined influence of orientation on growth rate and quality ofthe received monocrystals.

Expansion of lymph node metastasis in mixed-type submucosal invasive gastric cancer.

PubMed

Mikami, Koji; Hirano, Yukiko; Futami, Kitaro; Maekawa, Takafumi

2017-07-18

Mixed-type early gastric cancer (differentiated and undifferentiated components) incurs a higher risk of lymph node metastasis than pure-type early gastric cancer (only differentiated or only undifferentiated components). Therefore, we investigated the expansion of lymph node metastasis in mixed-type submucosal invasive gastric cancer in order to establish the most appropriate treatment for mixed-type cancer. We retrospectively analyzed 279 consecutive patients with submucosal invasive gastric cancer who underwent curative gastrectomy for gastric cancer between 1996 and 2015. We classified the patients into the mixed-type and pure-type groups according to histologic examination and evaluated the expansion of lymph node metastasis. The rate of lymph node metastasis was 23.7% (66/279) in the total patients, 36.4% (36/99) in the mixed-type group, and 16.6% (30/180) in the pure-type group. The significant independent risk factors for lymph node metastasis were tumor size ≥2.0 cm (P = 0.014), mixed-type gastric cancer (P < 0.001), and lymphatic invasion (P < 0.001). Lymphatic invasion and lymph node metastasis had a strong relationship in mixed-type group. The rates of no. 7 lymph node metastasis in the total patients and mixed-type group were 2.9% (8/279) and 5.1% (5/99), respectively; the rates of no. 8a lymph node metastasis were 1.4% (4/279) and 4.0% (4/99), respectively. Mixed histological type is an independent risk factor for lymph node metastasis. Lymph node metastasis in mixed-type gastric cancer involves expansion to the no. 7 and no. 8a lymph nodes. Therefore, lymphadenectomy for mixed-type submucosal invasive gastric cancer requires D1+ or D2 dissection. Copyright © 2017. Published by Elsevier Taiwan.

Role of a Modulator in the Synthesis of Phase-Pure NU-1000.

PubMed

Webber, Thomas E; Liu, Wei-Guang; Desai, Sai Puneet; Lu, Connie C; Truhlar, Donald G; Penn, R Lee

2017-11-15

NU-1000 is a robust, mesoporous metal-organic framework (MOF) with hexazirconium nodes ([Zr 6 O 16 H 16 ] 8+ , referred to as oxo-Zr 6 nodes) that can be synthesized by combining a solution of ZrOCl 2 ·8H 2 O and a benzoic acid modulator in N,N-dimethylformamide with a solution of linker (1,3,6,8-tetrakis(p-benzoic acid)pyrene, referred to as H 4 TBAPy) and by aging at an elevated temperature. Typically, the resulting crystals are primarily composed of NU-1000 domains that crystallize with a more dense phase that shares structural similarity with NU-901, which is an MOF composed of the same linker molecules and nodes. Density differences between the two polymorphs arise from the differences in the node orientation: in NU-1000, the oxo-Zr 6 nodes rotate 120° from node to node, whereas in NU-901, all nodes are aligned in parallel. Considering this structural difference leads to the hypothesis that changing the modulator from benzoic acid to a larger and more rigid biphenyl-4-carboxylic acid might lead to a stronger steric interaction between the modulator coordinating on the oxo-Zr 6 node and misaligned nodes or linkers in the large pore and inhibit the growth of the more dense NU-901-like material, resulting in phase-pure NU-1000. Side-by-side reactions comparing the products of synthesis using benzoic acid or biphenyl-4-carboxylic acid as a modulator produce structurally heterogeneous crystals and phase-pure NU-1000 crystals. It can be concluded that the larger and more rigid biphenyl-4-carboxylate inhibits the incorporation of nodes with an alignment parallel to the neighboring nodes already residing in the crystal.

[Application of lymph node labeling with carbon nanoparticles by preoperative endoscopic subserosal injection in laparoscopic radical gastrectomy].

PubMed

Hong, Q; Wang, Y; Wang, J J; Hu, C G; Fang, Y J; Fan, X X; Liu, T; Tong, Q

2017-01-10

Objective: To evaluate the application value of carbon lymph node tracing technique by preoperative endoscopic subserosal injection in laparoscopic radical gastrectomy. Methods: From June 2013 to February 2015, seventy eight patients with gastric cancer were enrolled and randomly divided into trial group and control group. Subserosal injection of carbon nanoparticles around the tumor was performed by preoperative endoscopic subserosal injection one day before the operation in trial group, while the patients routinely underwent laparoscopic gastrectomy in control group. Results of harvested lymph nodes, postoperative complications were compared between the two groups. Carbon nanoparticle-related side effect was also evaluated. Results: The average number of harvested lymph node in trial group was significantly higher than that in control group (35.5±8.5 vs 29.5±6.5, P <0.05). The rate of overall black-dyed harvested lymph node was 74.7% (1 035/1 386) in trial group, the black-dyed lymph node rate in D1 lymph node was 80.1%, which was significantly higher than that in D2 lymph node (69.8%, χ 2 =19.38, P <0.01). When comparing the lymph node with and without black-dyed in trial group, the rate of metastasis lymph node was significantly higher in lymph node with black-dyed (17.3% vs 4.0%, χ 2 =38.67, P <0.01). There was no significant difference in postoperative complications rate between two group (trial group 10.2%; control group 12.8%, χ 2 =0.00, P >0.05), and no carbon nanoparticle-related side effect was observed. Conclusion: Given a higher harvested lymph node number and a similar rate of complications, preoperative endoscopic subserosal injection of carbon nanoparticles was safe and feasible.

A Biologically-Inspired Neural Network Architecture for Image Processing

DTIC Science & Technology

1990-12-01

was organized into twelve groups of 8-by-8 node arrays. Weights were con- strained for each group of nodes, with each node "viewing" a 5-by-5 pixel...single wIndow * smk 0; for(J-0; j< 6 4 ; J++)( sum -sum +t %borfi][J]*rfarray[j]; ) /* Finished calculating ore block, one j:,,sition (first layer

User Instructions for the EPIC-2 Code.

DTIC Science & Technology

1986-09-01

10 1 TAM IIFAILIDARAC EFAIL 5 MATERIAL CARDS FOR SOLIDS INPUT DATA L45,5X, FSO, A48. R(8FDO.OJ, MATL I WAR I iAIL "EFAILMAtEA :SCRIPT ION DENSITY SPH...failure of the elements must be achieved by the eroding interface algorithm, it is important that EFAIL (a mate- rial property) be much greater than ERODE...If left blank (DFRAC z 0) factor will be set to DFRAC = 1.0 EFAIL = Equivalent plastic strain (true) which, if exceeded, will totally fail the element

Quantifying uncertainties in the structural response of SSME blades

NASA Technical Reports Server (NTRS)

Nagpal, Vinod K.

1987-01-01

To quantify the uncertainties associated with the geometry and material properties of a Space Shuttle Main Engine (SSME) turbopump blade, a computer code known as STAEBL was used. A finite element model of the blade used 80 triangular shell elements with 55 nodes and five degrees of freedom per node. The whole study was simulated on the computer and no real experiments were conducted. The structural response has been evaluated in terms of three variables which are natural frequencies, root (maximum) stress, and blade tip displacements. The results of the study indicate that only the geometric uncertainties have significant effects on the response. Uncertainties in material properties have insignificant effects.

3-D Wave-Structure Interaction with Coastal Sediments - A Multi-Physics/Multi-Solution Techniques Approach

DTIC Science & Technology

2007-01-01

Stokes (RANS) and the particle finite element method ( PFEM ) will be used in the water/mine/sand domain. Sand and the geomaterials around the sand will...wave propagation over a bottom mine at various time steps (Soil and Foam model) 8 SOLID/FEM SAND/SPH GEOMATERIALS FNPF/BEM FNPF/BEM RANS/ PFEM

Face-based smoothed finite element method for real-time simulation of soft tissue

NASA Astrophysics Data System (ADS)

Mendizabal, Andrea; Bessard Duparc, Rémi; Bui, Huu Phuoc; Paulus, Christoph J.; Peterlik, Igor; Cotin, Stéphane

2017-03-01

In soft tissue surgery, a tumor and other anatomical structures are usually located using the preoperative CT or MR images. However, due to the deformation of the concerned tissues, this information suffers from inaccuracy when employed directly during the surgery. In order to account for these deformations in the planning process, the use of a bio-mechanical model of the tissues is needed. Such models are often designed using the finite element method (FEM), which is, however, computationally expensive, in particular when a high accuracy of the simulation is required. In our work, we propose to use a smoothed finite element method (S-FEM) in the context of modeling of the soft tissue deformation. This numerical technique has been introduced recently to overcome the overly stiff behavior of the standard FEM and to improve the solution accuracy and the convergence rate in solid mechanics problems. In this paper, a face-based smoothed finite element method (FS-FEM) using 4-node tetrahedral elements is presented. We show that in some cases, the method allows for reducing the number of degrees of freedom, while preserving the accuracy of the discretization. The method is evaluated on a simulation of a cantilever beam loaded at the free end and on a simulation of a 3D cube under traction and compression forces. Further, it is applied to the simulation of the brain shift and of the kidney's deformation. The results demonstrate that the method outperforms the standard FEM in a bending scenario and that has similar accuracy as the standard FEM in the simulations of the brain-shift and of the kidney's deformation.

Finite Rotation Analysis of Highly Thin and Flexible Structures

NASA Technical Reports Server (NTRS)

Clarke, Greg V.; Lee, Keejoo; Lee, Sung W.; Broduer, Stephen J. (Technical Monitor)

2001-01-01

Deployable space structures such as sunshields and solar sails are extremely thin and highly flexible with limited bending rigidity. For analytical investigation of their responses during deployment and operation in space, these structures can be modeled as thin shells. The present work examines the applicability of the solid shell element formulation to modeling of deployable space structures. The solid shell element formulation that models a shell as a three-dimensional solid is convenient in that no rotational parameters are needed for the description of kinematics of deformation. However, shell elements may suffer from element locking as the thickness becomes smaller unless special care is taken. It is shown that, when combined with the assumed strain formulation, the solid shell element formulation results in finite element models that are free of locking even for extremely thin structures. Accordingly, they can be used for analysis of highly flexible space structures undergoing geometrically nonlinear finite rotations.

Distinct regulators of Shh transcription in the floor plate and notochord indicate separate origins for these tissues in the mouse node.

PubMed

Jeong, Yongsu; Epstein, Douglas J

2003-08-01

The establishment of the floor plate at the ventral midline of the CNS is dependent on an inductive signaling process mediated by the secreted protein Sonic hedgehog (Shh). To understand molecularly how floor plate induction proceeds we identified a Shh-responsive regulatory element that directs transgene reporter expression to the ventral midline of the CNS and notochord in a Shh-like manner and characterized critical cis-acting sequences regulating this element. Cross-species comparisons narrowed the activity of the Shh floor plate enhancer to an 88-bp sequence within intron 2 of Shh that included highly conserved binding sites matching the consensus for homeodomain, Tbx and Foxa transcription factors. Mutational analysis revealed that the homeodomain and Foxa binding sites are each required for activation of the Shh floor plate enhancer, whereas the Tbx site was required for repression in regions of the CNS where Shh is not normally expressed. We further show that Shh enhancer activity was detected in the mouse node from where the floor plate and notochord precursors derive. Shh reporter expression was restricted to the ventral (mesodermal) layer of the node in a pattern similar to endogenous Shh. X-gal-positive cells emerging from the node were only detected in the notochord lineage, suggesting that the floor plate and notochord arise from distinct precursors in the mouse node.

Micromotion and stress distribution of immediate loaded implants: a finite element analysis.

PubMed

Fazel, A; Aalai, S; Rismanchian, M; Sadr-Eshkevari, P

2009-12-01

Primary stability and micromotion of the implant fixture is mostly influenced by its macrodesign. To assess and compare the peri-implant stress distribution and micromotion of two types of immediate loading implants, immediate loaded screw (ILS) Nisastan and Xive (DENTSPLY/Friadent, Monnheim, Germany), and to determine the best macrodesign of these two implants by finite element analysis. In this experimental study, the accurate pictures of two fixtures (ILS: height = 13, diameter = 4 mm and Xive: height = 13, diameter = 3.8 mm) were taken by a new digital camera (Nikon Coolpix 5700 [Nikon, Japan], resolution = 5.24 megapixel, lens = 8x optical, 4x digital zoom). Following accurate measurements, the three-dimensional finite element computer model was simulated and inserted in simulated mandibular bone (D(2)) in SolidWorks 2003 (SolidWork Corp., MA, USA) and Ansys 7.1 (Ansys, Inc., Canonsburg, PA, USA). After loading (500 N, 75 degrees above horizon), the displacement was displayed and von Mises stress was recorded. It was found that the primary stability of ILS was greater (152 microm) than Xive (284 microm). ILS exhibited more favorable stress distribution. Maximum stress concentration found in periapical bone around Xive ( approximately 30 MPa) was lesser than Nisastan ( approximately 37 MPa). Macrodesign of ILS leads to better primary stability and stress distribution. Maximum stress around Xive was less.

PSMA PET/CT with Glu-urea-Lys-(Ahx)-[⁶⁸Ga(HBED-CC)] versus 3D CT volumetric lymph node assessment in recurrent prostate cancer.

PubMed

Giesel, Frederik L; Fiedler, H; Stefanova, M; Sterzing, F; Rius, M; Kopka, K; Moltz, J H; Afshar-Oromieh, A; Choyke, P L; Haberkorn, U; Kratochwil, C

2015-11-01

PET/CT with the PSMA ligand is a powerful new method for the early detection of nodal metastases in patients with biochemical relapse. The purpose of this retrospective investigation was to evaluate the volume and dimensions of nodes identified by Glu-urea-Lys-(Ahx)-[(68)Ga(HBED-CC)] ((68)Ga-PSMA-11) in the setting of recurrent prostate cancer. All PET/CT images were acquired 60 ± 10 min after intravenous injection of (68)Ga-PSMA-11 (mean dose 176 MBq). In 21 patients with recurrent prostate cancer and rising PSA, 49 PSMA-positive lymph nodes were identified. Using semiautomated lymph node segmentation software, node volume and short-axis and long-axis dimensions were measured and compared with the maximum standardized uptake values (SUVmax). Round nodes greater than or equal to 8 mm were considered positive by morphological criteria alone. The percentage of nodes identified by elevated SUVmax but not by conventional morphological criteria was determined. The mean volume of (68)Ga-PSMA-11-positive nodes was 0.5 ml (range 0.2 - 2.3 ml), and the mean short-axis diameter was 5.8 mm (range 2.4 - 13.3 mm). In 7 patients (33.3 %) with 31 PSMA-positive nodes only 11 (36 %) were morphologically positive based on diameters >8 mm on CT. In the remaining 14 patients (66.7 %), 18 (37 %) of PSMA positive lymph nodes had short-axis diameters <8 mm with a mean short-axis diameter of 5.0 mm (range 2.4 - 7.9 mm). Thus, in this population, (68)Ga-PSMA-11 PET/CT detected nodal recurrence in two-thirds of patients who would have been missed using conventional morphological criteria. (68)Ga-PSMA-11 PET/CT is more sensitive than CT based 3D volumetric lymph node evaluation in determining the node status of patients with recurrent prostate cancer, and is a promising method of restaging prostate cancers in this setting.

Source Mechanism of May 30, 2015 Bonin Islands, Japan Deep Earthquake (Mw7.8) Estimated by Broadband Waveform Modeling

NASA Astrophysics Data System (ADS)

Tsuboi, S.; Nakamura, T.; Miyoshi, T.

2015-12-01

May 30, 2015 Bonin Islands, Japan earthquake (Mw 7.8, depth 679.9km GCMT) was one of the deepest earthquakes ever recorded. We apply the waveform inversion technique (Kikuchi & Kanamori, 1991) to obtain slip distribution in the source fault of this earthquake in the same manner as our previous work (Nakamura et al., 2010). We use 60 broadband seismograms of IRIS GSN seismic stations with epicentral distance between 30 and 90 degrees. The broadband original data are integrated into ground displacement and band-pass filtered in the frequency band 0.002-1 Hz. We use the velocity structure model IASP91 to calculate the wavefield near source and stations. We assume that the fault is squared with the length 50 km. We obtain source rupture model for both nodal planes with high dip angle (74 degree) and low dip angle (26 degree) and compare the synthetic seismograms with the observations to determine which source rupture model would explain the observations better. We calculate broadband synthetic seismograms with these source propagation models using the spectral-element method (Komatitsch & Tromp, 2001). We use new Earth Simulator system in JAMSTEC to compute synthetic seismograms using the spectral-element method. The simulations are performed on 7,776 processors, which require 1,944 nodes of the Earth Simulator. On this number of nodes, a simulation of 50 minutes of wave propagation accurate at periods of 3.8 seconds and longer requires about 5 hours of CPU time. Comparisons of the synthetic waveforms with the observation at teleseismic stations show that the arrival time of pP wave calculated for depth 679km matches well with the observation, which demonstrates that the earthquake really happened below the 660 km discontinuity. In our present forward simulations, the source rupture model with the low-angle fault dipping is likely to better explain the observations.

Path-integral simulation of solids.

PubMed

Herrero, C P; Ramírez, R

2014-06-11

The path-integral formulation of the statistical mechanics of quantum many-body systems is described, with the purpose of introducing practical techniques for the simulation of solids. Monte Carlo and molecular dynamics methods for distinguishable quantum particles are presented, with particular attention to the isothermal-isobaric ensemble. Applications of these computational techniques to different types of solids are reviewed, including noble-gas solids (helium and heavier elements), group-IV materials (diamond and elemental semiconductors), and molecular solids (with emphasis on hydrogen and ice). Structural, vibrational, and thermodynamic properties of these materials are discussed. Applications also include point defects in solids (structure and diffusion), as well as nuclear quantum effects in solid surfaces and adsorbates. Different phenomena are discussed, as solid-to-solid and orientational phase transitions, rates of quantum processes, classical-to-quantum crossover, and various finite-temperature anharmonic effects (thermal expansion, isotopic effects, electron-phonon interactions). Nuclear quantum effects are most remarkable in the presence of light atoms, so that especial emphasis is laid on solids containing hydrogen as a constituent element or as an impurity.

Free vibration of laminated composite stiffened hyperbolic paraboloid shell panel with cutout

NASA Astrophysics Data System (ADS)

Sahoo, Sarmila

2016-08-01

Composite shell structures are extensively used in aerospace, civil, marine and other engineering applications. In practical civil engineering applications, the necessity of covering large column free open areas is often an issue and hyperbolic paraboloid shells are used as roofing units. Quite often, to save weight and also to provide a facility for inspection, cutouts are provided in shell panels. The paper considers free vibration characteristics of stiffened composite hyperbolic paraboloid shell panel with cutout in terms of natural frequency and mode shapes. A finite element code is developed for the purpose by combining an eight noded curved shell element with a three noded curved beam element. The size of the cutouts and their positions with respect to the shell centre are varied for different edge conditions to arrive at a set of inferences of practical engineering significances.

Integration of Mesh Optimization with 3D All-Hex Mesh Generation, LDRD Subcase 3504340000, Final Report

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

KNUPP,PATRICK; MITCHELL,SCOTT A.

1999-11-01

In an attempt to automatically produce high-quality all-hex meshes, we investigated a mesh improvement strategy: given an initial poor-quality all-hex mesh, we iteratively changed the element connectivity, adding and deleting elements and nodes, and optimized the node positions. We found a set of hex reconnection primitives. We improved the optimization algorithms so they can untangle a negative-Jacobian mesh, even considering Jacobians on the boundary, and subsequently optimize the condition number of elements in an untangled mesh. However, even after applying both the primitives and optimization we were unable to produce high-quality meshes in certain regions. Our experiences suggest that manymore » boundary configurations of quadrilaterals admit no hexahedral mesh with positive Jacobians, although we have no proof of this.« less

Comparison of systematic mediastinal lymph node dissection versus systematic sampling for lung cancer staging and completeness of surgery.

PubMed

Wu, Nan; Yan, Shi; Lv, Chao; Feng, Yuan; Wang, Yuzhao; Zhang, Lijian; Yang, Yue

2011-12-01

This self-controlled prospective study was designed to investigate the efficacy of systematic sampling (SS), compared with systematic mediastinal lymph node dissection (SMLD), for pathologic staging and completeness of surgery. Over a period of 11 mo, 110 patients with lung cancer were enlisted and treated by pulmonary resection. Surgeons systematically sampled mediastinal lymph nodes prior to pulmonary resection, and after pulmonary resection SMLD was performed to each patient using Mountain's procedure [1]. After SMLD, pN status was classified as N0 in 57 cases, N1 in 27, and N2 in 26. SS detected 38.3% of pooled nodes and 37.6% of pooled positive nodes collected from SMLD. Pathologic diagnosis after SS was understaged in nine cases (8.2%) compared with staging after SMLD. However, surgery was incomplete in 24 cases (21.8%) if SMLD was not performed after sampling. Negative predictive value for SS was 86.8% on the right side, and 95.0% on the left. Three categories were generated according to pN status: negative nodes in SS and additional negative nodes from SMLD [S(-)D(-)], negative nodes in SS but additional positive nodes from SMLD [S(-)D(+)], and positive nodes in SS [S(+)D(+)]. cN2 (P=0.000) and CEA level (P=0.001) were correlated with pN status. There was significant overall survival difference between non-N2 group and N2 group (P=0.002). SMLD may harvest about three times of mediastinal lymph nodes compared with SS. SS is more likely to affect the completeness of surgery instead of underrating pathologic stage. Copyright © 2011 Elsevier Inc. All rights reserved.

Improved Survival in Male Melanoma Patients in the Era of Sentinel Node Biopsy.

PubMed

Koskivuo, I; Vihinen, P; Mäki, M; Talve, L; Vahlberg, T; Suominen, E

2017-03-01

Sentinel node biopsy is a standard method for nodal staging in patients with clinically localized cutaneous melanoma, but the survival advantage of sentinel node biopsy remains unsolved. The aim of this case-control study was to investigate the survival benefit of sentinel node biopsy. A total of 305 prospective melanoma patients undergoing sentinel node biopsy were compared with 616 retrospective control patients with clinically localized melanoma whom have not undergone sentinel node biopsy. Survival differences were calculated with the median follow-up time of 71 months in sentinel node biopsy patients and 74 months in control patients. Analyses were calculated overall and separately in males and females. Overall, there were no differences in relapse-free survival or cancer-specific survival between sentinel node biopsy patients and control patients. Male sentinel node biopsy patients had significantly higher relapse-free survival ( P = 0.021) and cancer-specific survival ( P = 0.024) than control patients. In females, no differences were found. Cancer-specific survival rates at 5 years were 87.8% in sentinel node biopsy patients and 85.2% in controls overall with 88.3% in male sentinel node biopsy patients and 80.6% in male controls and 87.3% in female sentinel node biopsy patients and 89.8% in female controls. Sentinel node biopsy did not improve survival in melanoma patients overall. While females had no differences in survival, males had significantly improved relapse-free survival and cancer-specific survival following sentinel node biopsy.

Caspase-3/-8/-9, Bax and Bcl-2 expression in the cerebellum, lymph nodes and leukocytes of dogs naturally infected with canine distemper virus.

PubMed

Del Puerto, H L; Martins, A S; Moro, L; Milsted, A; Alves, F; Braz, G F; Vasconcelos, A C

2010-01-26

Canine distemper is an immunosuppressive disease caused by the canine distemper virus (CDV). Pathogenesis mainly involves the central nervous system and immunosuppression. Dogs naturally infected with CDV develop apoptotic cells in lymphoid tissues and the cerebellum, but this apoptotic mechanism is not well characterized. To better understand this process, we evaluated the expression of Bax, Bcl-2, and caspase-3, -8 and -9, by evaluating mRNA levels in the peripheral blood, lymph nodes and cerebellum of CDV-infected (CDV+) and uninfected (CDV-) dogs by real-time polymerase chain reaction (PCR). Blood samples from 12 CDV+ and 8 CDV- dogs, diagnosed by reverse transcription-PCR, were subjected to hematological analysis and apoptotic gene expression was evaluated using real-time-PCR. Tissues from the cerebellum and lymph nodes of four CDV+ and three CDV-dogs were also subjected to real time-PCR. No significant differences were found between CDV+ and CDV- dogs in the hemotological results or in the expression of caspase-3, -8, -9, Bax, and Bcl-2 in the peripheral blood. However, expression of Bax, caspase-3, -8 and -9 was significantly higher in the cerebellum of CDV+ compared to CDV- dogs. Expression of caspase-3 and -8 was significantly higher in the lymph nodes of CDV+ compared to CDV- dogs. We concluded that infection with CDV induces apoptosis in the cerebellum and lymph nodes in different ways. Lymph node apoptosis apparently occurs via caspase-3 activation, through the caspase-8 pathway, and cerebellum apoptosis apparently occurs via caspase-3 activation, through the caspase-8 and mitochondrial pathways.

KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility observe consoles during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by the National Space Development Agency of Japan (NASDA), is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

NASA Image and Video Library

2003-09-03

KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility observe consoles during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by the National Space Development Agency of Japan (NASDA), is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

KENNEDY SPACE CENTER, FLA. - Technicians in the Space Station Processing Facility work on a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by the National Space Development Agency of Japan (NASDA), is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

NASA Image and Video Library

2003-09-03

KENNEDY SPACE CENTER, FLA. - Technicians in the Space Station Processing Facility work on a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by the National Space Development Agency of Japan (NASDA), is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

Cerium-Hydride Secondary Building Units in a Porous Metal–Organic Framework for Catalytic Hydroboration and Hydrophosphination

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

Ji, Pengfei; Sawano, Takahiro; Lin, Zekai

2016-11-16

We report the stepwise, quantitative transformation of CeIV6(μ3-O)4(μ3-OH)4(OH)6(OH2)6 nodes in a new Ce-BTC (BTC = trimesic acid) metal–organic framework (MOF) into the first CeIII6(μ3-O)4(μ3-OLi)4(H)6(THF)6Li6 metal-hydride nodes that effectively catalyze hydroboration and hydrophosphination reactions. CeH-BTC displays low steric hindrance and electron density compared to homogeneous organolanthanide catalysts, which likely accounts for the unique 1,4-regioselectivity for the hydroboration of pyridine derivatives. MOF nodes can thus be directly transformed into novel single-site solid catalysts without homogeneous counterparts for sustainable chemical synthesis.

Long-lasting solid-polymer electrolytic hygrometer

NASA Technical Reports Server (NTRS)

Lawson, D. D.

1978-01-01

Device consists of hollow tube node of oxidation-resistant sulfonated fluorocarbon polymer. Tube absorbs moisture from air passing across inner and outer surfaces, causing change in polymer conductance. Change is related to change in water content in gas sample.

Solid state light source driver establishing buck or boost operation

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

Palmer, Fred

A solid state light source driver circuit that operates in either a buck convertor or a boost convertor configuration is provided. The driver circuit includes a controller, a boost switch circuit and a buck switch circuit, each coupled to the controller, and a feedback circuit, coupled to the light source. The feedback circuit provides feedback to the controller, representing a DC output of the driver circuit. The controller controls the boost switch circuit and the buck switch circuit in response to the feedback signal, to regulate current to the light source. The controller places the driver circuit in its boostmore » converter configuration when the DC output is less than a rectified AC voltage coupled to the driver circuit at an input node. The controller places the driver circuit in its buck converter configuration when the DC output is greater than the rectified AC voltage at the input node.« less

Three dimensional modeling of rigid pavement : executive summary, February 1995.

DOT National Transportation Integrated Search

1995-02-17

A finite-element program has been developed to model the response of rigid pavement to both static loads and temperature changes. The program is fully three-dimensional and incorporates not only the common twenty-node brick element but also a thin in...

Three-dimensional modeling of rigid pavement : final report, September 1995.

DOT National Transportation Integrated Search

1995-02-17

A finite-element program has been developed to model the response of rigid pavement to both static loads and temperature changes. The program is fully three-dimensional and incorporates not only the common twenty-node brick element but also a thin in...

Quasi-Static Viscoelastic Finite Element Model of an Aircraft Tire

NASA Technical Reports Server (NTRS)

Johnson, Arthur R.; Tanner, John A.; Mason, Angela J.

1999-01-01

An elastic large displacement thick-shell mixed finite element is modified to allow for the calculation of viscoelastic stresses. Internal strain variables are introduced at the element's stress nodes and are employed to construct a viscous material model. First order ordinary differential equations relate the internal strain variables to the corresponding elastic strains at the stress nodes. The viscous stresses are computed from the internal strain variables using viscous moduli which are a fraction of the elastic moduli. The energy dissipated by the action of the viscous stresses is included in the mixed variational functional. The nonlinear quasi-static viscous equilibrium equations are then obtained. Previously developed Taylor expansions of the nonlinear elastic equilibrium equations are modified to include the viscous terms. A predictor-corrector time marching solution algorithm is employed to solve the algebraic-differential equations. The viscous shell element is employed to computationally simulate a stair-step loading and unloading of an aircraft tire in contact with a frictionless surface.

Radionavigated detection of sentinel nodes in breast carcinoma--first experiences of our department.

PubMed

Duchaj, B; Chvalny, P; Vesely, J; Makaiova, I; Durdik, S; Straka, V; Palaj, J; Procka, V; Aksamitova, K; Skraskova, S; Banki, P; Kovacova, S; Galbavy, S

2010-01-01

Biopsy and histological evaluation of sentinel lymphatic node limits the axillary node dissection only in cases of positive histological finding and decreases the occurrence of postoperative complications related to the axillary node dissection. We used radiotracer SentiScint, Medi-Radiopharma Ltd, Hungary and preoperatively administered blue dye--Blue Patenté V, Guebert, Aulnay-Sous-Bios, France. 11 (18%) patients were subdued to deep peritimorous application of radiotracer, 10 (16.4%) to sub/intradermal application over the lesions and n 40 (65.6%) patients the application was sub/intradermal and periareolar. The patients underwent an operation protocol of corresponding quadrantectomy, radionavigated blue-dye sentinel node biopsy and axillary dissection. From May 2006 to June 2008, we examined 61 patients with breast carcinoma. They underwent radionavigated and blue-dye sentinel node biopsy. We detected 57 (93.4%) sentinel nodes with preoperative scintigraphy, of which only 51 (83.6%) were detected peroperatively and underwent histological evaluation. In six (9.8%) cases, the "frozen cut" histology of the primary lesion had shown a benign lesion; hence no sentinel node biopsy or axillary disection was performed. 12 (19.7%) of 51 histologically evaluated sentinel nodes had metastatic invasion. We retrospectively compared the histological fund in sentinel and axillary nodes in patients with metastatic sentinel nodes. In 6 (16.6%) cases, the sentinel node was positive of metastatic invasion but axillary nodes were histologically negative, in 6 (16.6%) cases the sentinel node and axillary nodes were positive for metastatic invasion. We observed falsely negative findings in 3 (8.3%) patients with negative histological fund in the sentinel node, but positive axillary nodes (Tab. 3, Fig. 2, Ref. 11). Full Text (Free, PDF) www.bmj.sk.

Use of Exogenous Progestins and Risk or In Situ and Invasive Breast Cancer

DTIC Science & Technology

2011-10-01

will be funded by the parent R01 (NCI) grant, and not by the Era of Hope Scholar Award. Table 1: Participant enrollment report Project 2 Project 1...of lobular tumors that were node positive, PR+, e-cadherin negative , and had low p21 expression (Table 6). No differences were seen across the other...Node negative 61% 1.2 (0.8-2.0) 63% 1.9 (1.04-3.4) Node positive 31% 0.9 (0.5-1.7) 37% 3.7 (1.8-7.8) PR+ 89% 1.2 (0.8-1.9) 84% 2.9 (1.7-5.1) PR- 11

Design and Implementation of a Wireless Sensor Network of GPS-enabled Seismic Sensors for the Study of Glaciers and Ice Sheets

NASA Astrophysics Data System (ADS)

Bilen, S. G.; Anandakrishnan, S.; Urbina, J. V.

2012-12-01

In an effort to provide new and improved geophysical sensing capabilities for the study of ice sheets in Antarctica and Greenland, or to study mountain glaciers, we are developing a network of wirelessly interconnected seismic and GPS sensor nodes (called "geoPebbles"), with the primary objective of making such instruments more capable and cost effective. We describe our design methodology, which has enabled us to develop these state-of-the art sensors using commercial-off-the-shelf hardware combined with custom-designed hardware and software. Each geoPebble is a self-contained, wirelessly connected sensor for collecting seismic measurements and position information. Each node is built around a three-component seismic recorder, which includes an amplifier, filter, and 24-bit analog-to-digital card that can sample up to 10 kHz. Each unit also includes a microphone channel to record the ground-coupled airwave. The timing for each node is available through a carrier-phase measurement of the L1 GPS signal at an absolute accuracy of better than a microsecond. Each geoPebble includes 16 GB of solid-state storage, wireless communications capability to a central supervisory unit, and auxiliary measurements capability (up to eight 10-bit channels at low sample rates). We will report on current efforts to test this new instrument and how we are addressing the challenges imposed by the extreme weather conditions on the Antarctic continent. After fully validating its operational conditions, the geoPebble system will be available for NSF-sponsored glaciology research projects. Geophysical experiments in the polar region are logistically difficult. With the geoPebble system, the cost of doing today's experiments (low-resolution, 2D) will be significantly reduced, and the cost and feasibility of doing tomorrow's experiments (integrated seismic, positioning, 3D, etc.) will be reasonable. Sketch of an experiment with geoPebbles scattered on the surface of the ice sheet. The seismic source can move through the array. The SQC node communicates with all the elements in the array.

SEACAS Theory Manuals: Part III. Finite Element Analysis in Nonlinear Solid Mechanics

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

Laursen, T.A.; Attaway, S.W.; Zadoks, R.I.

1999-03-01

This report outlines the application of finite element methodology to large deformation solid mechanics problems, detailing also some of the key technological issues that effective finite element formulations must address. The presentation is organized into three major portions: first, a discussion of finite element discretization from the global point of view, emphasizing the relationship between a virtual work principle and the associated fully discrete system, second, a discussion of finite element technology, emphasizing the important theoretical and practical features associated with an individual finite element; and third, detailed description of specific elements that enjoy widespread use, providing some examples ofmore » the theoretical ideas already described. Descriptions of problem formulation in nonlinear solid mechanics, nonlinear continuum mechanics, and constitutive modeling are given in three companion reports.« less

Fabrication and testing of a 4-node micro-pocket fission detector array for the Kansas State University TRIGA Mk. II research nuclear reactor

NASA Astrophysics Data System (ADS)

Reichenberger, Michael A.; Nichols, Daniel M.; Stevenson, Sarah R.; Swope, Tanner M.; Hilger, Caden W.; Unruh, Troy C.; McGregor, Douglas S.; Roberts, Jeremy A.

2017-08-01

Advancements in nuclear reactor core modeling and computational capability have encouraged further development of in-core neutron sensors. Micro-Pocket Fission Detectors (MPFDs) have been fabricated and tested previously, but successful testing of these prior detectors was limited to single-node operation with specialized designs. Described in this work is a modular, four-node MPFD array fabricated and tested at Kansas State University (KSU). The four sensor nodes were equally spaced to span the length of the fuel-region of the KSU TRIGA Mk. II research nuclear reactor core. The encapsulated array was filled with argon gas, serving as an ionization medium in the small cavities of the MPFDs. The unified design improved device ruggedness and simplified construction over previous designs. A 0.315-in. (8-mm) penetration in the upper grid plate of the KSU TRIGA Mk. II research nuclear reactor was used to deploy the array between fuel elements in the core. The MPFD array was coupled to an electronic support system which has been developed to support pulse-mode operation. Neutron-induced pulses were observed on all four sensor channels. Stable device operation was confirmed by testing under steady-state reactor conditions. Each of the four sensors in the array responded to changes in reactor power between 10 kWth and full power (750 kWth). Reactor power transients were observed in real-time including positive transients with periods of 5, 15, and 30 s. Finally, manual reactor power oscillations were observed in real-time.

Assembly Mechanism of the Contractile Ring for Cytokinesis by Fission Yeast

NASA Astrophysics Data System (ADS)

Vavylonis, Dimitrios; Wu, Jian-Qiu; Huang, Xiaolei; O'Shaughnessy, Ben; Pollard, Thomas

2008-03-01

Animals and fungi assemble a contractile ring of actin filaments and the motor protein myosin to separate into individual daughter cells during cytokinesis. We studied the mechanism of contractile ring assembly in fission yeast with high time resolution confocal microscopy, computational image analysis methods, and numerical simulations. Approximately 63 nodes containing myosin, broadly distributed around the cell equator, assembled into a ring through stochastic motions, making many starts, stops, and changes of direction as they condense into a ring. Estimates of node friction coefficients from the mean square displacement of stationary nodes imply forces for node movement are greater than ˜ 4 pN, similarly to forces by a few molecular motors. Skeletonization and topology analysis of images of cells expressing fluorescent actin filament markers showed transient linear elements extending in all directions from myosin nodes and establishing connections among them. We propose a model with traction between nodes depending on transient connections established by stochastic search and capture (``search, capture, pull and release''). Numerical simulations of the model using parameter values obtained from experiment succesfully condense nodes into a continuous ring.

Establishing the 3-D finite element solid model of femurs in partial by volume rendering.

PubMed

Zhang, Yinwang; Zhong, Wuxue; Zhu, Haibo; Chen, Yun; Xu, Lingjun; Zhu, Jianmin

2013-01-01

It remains rare to report three-dimensional (3-D) finite element solid model of femurs in partial by volume rendering method, though several methods of femoral 3-D finite element modeling are already available. We aim to analyze the advantages of the modeling method by establishing the 3-D finite element solid model of femurs in partial by volume rendering. A 3-D finite element model of the normal human femurs, made up of three anatomic structures: cortical bone, cancellous bone and pulp cavity, was constructed followed by pretreatment of the CT original image. Moreover, the finite-element analysis was carried on different material properties, three types of materials given for cortical bone, six assigned for cancellous bone, and single for pulp cavity. The established 3-D finite element of femurs contains three anatomical structures: cortical bone, cancellous bone, and pulp cavity. The compressive stress primarily concentrated in the medial surfaces of femur, especially in the calcar femorale. Compared with whole modeling by volume rendering method, the 3-D finite element solid model created in partial is more real and fit for finite element analysis. Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Peregrine System | High-Performance Computing | NREL

Science.gov Websites

) and longer-term (/projects) storage. These file systems are mounted on all nodes. Peregrine has three -2670 Xeon processors and 64 GB of memory. In addition to mounting the /home, /nopt, /projects and # cores/node Memory/node Peak (DP) performance per node 88 Intel Xeon E5-2670 "Sandy Bridge" 8

Digital system for structural dynamics simulation

NASA Technical Reports Server (NTRS)

Krauter, A. I.; Lagace, L. J.; Wojnar, M. K.; Glor, C.

1982-01-01

State-of-the-art digital hardware and software for the simulation of complex structural dynamic interactions, such as those which occur in rotating structures (engine systems). System were incorporated in a designed to use an array of processors in which the computation for each physical subelement or functional subsystem would be assigned to a single specific processor in the simulator. These node processors are microprogrammed bit-slice microcomputers which function autonomously and can communicate with each other and a central control minicomputer over parallel digital lines. Inter-processor nearest neighbor communications busses pass the constants which represent physical constraints and boundary conditions. The node processors are connected to the six nearest neighbor node processors to simulate the actual physical interface of real substructures. Computer generated finite element mesh and force models can be developed with the aid of the central control minicomputer. The control computer also oversees the animation of a graphics display system, disk-based mass storage along with the individual processing elements.

Linear magnetoconductivity in an intrinsic topological Weyl semimetal

NASA Astrophysics Data System (ADS)

Zhang, Song-Bo; Lu, Hai-Zhou; Shen, Shun-Qing

2016-05-01

Searching for the signature of the violation of chiral charge conservation in solids has inspired a growing passion for the magneto-transport in topological semimetals. One of the open questions is how the conductivity depends on magnetic fields in a semimetal phase when the Fermi energy crosses the Weyl nodes. Here, we study both the longitudinal and transverse magnetoconductivity of a topological Weyl semimetal near the Weyl nodes with the help of a two-node model that includes all the topological semimetal properties. In the semimetal phase, the Fermi energy crosses only the 0th Landau bands in magnetic fields. For a finite potential range of impurities, it is found that both the longitudinal and transverse magnetoconductivity are positive and linear at the Weyl nodes, leading to an anisotropic and negative magnetoresistivity. The longitudinal magnetoconductivity depends on the potential range of impurities. The longitudinal conductivity remains finite at zero field, even though the density of states vanishes at the Weyl nodes. This work establishes a relation between the linear magnetoconductivity and the intrinsic topological Weyl semimetal phase.

General framework for dynamic large deformation contact problems based on phantom-node X-FEM

NASA Astrophysics Data System (ADS)

Broumand, P.; Khoei, A. R.

2018-04-01

This paper presents a general framework for modeling dynamic large deformation contact-impact problems based on the phantom-node extended finite element method. The large sliding penalty contact formulation is presented based on a master-slave approach which is implemented within the phantom-node X-FEM and an explicit central difference scheme is used to model the inertial effects. The method is compared with conventional contact X-FEM; advantages, limitations and implementational aspects are also addressed. Several numerical examples are presented to show the robustness and accuracy of the proposed method.

System and method for modeling and analyzing complex scenarios

DOEpatents

Shevitz, Daniel Wolf

2013-04-09

An embodiment of the present invention includes a method for analyzing and solving possibility tree. A possibility tree having a plurality of programmable nodes is constructed and solved with a solver module executed by a processor element. The solver module executes the programming of said nodes, and tracks the state of at least a variable through a branch. When a variable of said branch is out of tolerance with a parameter, the solver disables remaining nodes of the branch and marks the branch as an invalid solution. The valid solutions are then aggregated and displayed as valid tree solutions.

Supercomputer implementation of finite element algorithms for high speed compressible flows

NASA Technical Reports Server (NTRS)

Thornton, E. A.; Ramakrishnan, R.

1986-01-01

Prediction of compressible flow phenomena using the finite element method is of recent origin and considerable interest. Two shock capturing finite element formulations for high speed compressible flows are described. A Taylor-Galerkin formulation uses a Taylor series expansion in time coupled with a Galerkin weighted residual statement. The Taylor-Galerkin algorithms use explicit artificial dissipation, and the performance of three dissipation models are compared. A Petrov-Galerkin algorithm has as its basis the concepts of streamline upwinding. Vectorization strategies are developed to implement the finite element formulations on the NASA Langley VPS-32. The vectorization scheme results in finite element programs that use vectors of length of the order of the number of nodes or elements. The use of the vectorization procedure speeds up processing rates by over two orders of magnitude. The Taylor-Galerkin and Petrov-Galerkin algorithms are evaluated for 2D inviscid flows on criteria such as solution accuracy, shock resolution, computational speed and storage requirements. The convergence rates for both algorithms are enhanced by local time-stepping schemes. Extension of the vectorization procedure for predicting 2D viscous and 3D inviscid flows are demonstrated. Conclusions are drawn regarding the applicability of the finite element procedures for realistic problems that require hundreds of thousands of nodes.

Performance evaluation of laser induced breakdown spectroscopy in the measurement of liquid and solid samples

NASA Astrophysics Data System (ADS)

Bilge, Gonca; Sezer, Banu; Boyaci, Ismail Hakki; Eseller, Kemal Efe; Berberoglu, Halil

2018-07-01

Liquid analysis by using LIBS is a complicated process due to difficulties encountered during the collection of light and formation of plasma in liquid. To avoid these, some applications are performed such as aerosol formation and transforming liquid into solid state. However, performance of LIBS in liquid samples still remains a challenging issue. In this study, performance evaluation of LIBS and parameter optimizations in liquid and solid phase samples were performed. For this purpose, milk was chosen as model sample; milk powder was used as solid sample, and milk was used as liquid sample in the experiments. Different experimental setups have been constructed for each sampling technique, and optimizations were performed to determine suitable parameters such as delay time, laser energy, repetition rate and speed of rotary table for solid sampling technique, and flow rate of carrier gas for liquid sampling technique. Target element was determined as Ca, which is a critically important element in milk for determining its nutritional value and Ca addition. In optimum parameters, limit of detection (LOD), limit of quantification (LOQ) and relative standard deviation (RSD) values were calculated as 0.11%, 0.36% and 8.29% respectively for milk powders samples; while LOD, LOQ and RSD values were calculated as 0.24%, 0.81%, and 10.93% respectively for milk samples. It can be said that LIBS is an applicable method in both liquid and solid samples with suitable systems and parameters. However, liquid analysis requires much more developed systems for more accurate results.

Correctness Proof of a Self-Stabilizing Distributed Clock Synchronization Protocol for Arbitrary Digraphs

NASA Technical Reports Server (NTRS)

Malekpour, Mahyar R.

2011-01-01

This report presents a deductive proof of a self-stabilizing distributed clock synchronization protocol. It is focused on the distributed clock synchronization of an arbitrary, non-partitioned digraph ranging from fully connected to 1-connected networks of nodes while allowing for differences in the network elements. This protocol does not rely on assumptions about the initial state of the system, and no central clock or a centrally generated signal, pulse, or message is used. Nodes are anonymous, i.e., they do not have unique identities. There is no theoretical limit on the maximum number of participating nodes. The only constraint on the behavior of the node is that the interactions with other nodes are restricted to defined links and interfaces. We present a deductive proof of the correctness of the protocol as it applies to the networks with unidirectional and bidirectional links. We also confirm the claims of determinism and linear convergence.

A grid-doubling finite-element technique for calculating dynamic three-dimensional spontaneous rupture on an earthquake fault

USGS Publications Warehouse

Barall, Michael

2009-01-01

We present a new finite-element technique for calculating dynamic 3-D spontaneous rupture on an earthquake fault, which can reduce the required computational resources by a factor of six or more, without loss of accuracy. The grid-doubling technique employs small cells in a thin layer surrounding the fault. The remainder of the modelling volume is filled with larger cells, typically two or four times as large as the small cells. In the resulting non-conforming mesh, an interpolation method is used to join the thin layer of smaller cells to the volume of larger cells. Grid-doubling is effective because spontaneous rupture calculations typically require higher spatial resolution on and near the fault than elsewhere in the model volume. The technique can be applied to non-planar faults by morphing, or smoothly distorting, the entire mesh to produce the desired 3-D fault geometry. Using our FaultMod finite-element software, we have tested grid-doubling with both slip-weakening and rate-and-state friction laws, by running the SCEC/USGS 3-D dynamic rupture benchmark problems. We have also applied it to a model of the Hayward fault, Northern California, which uses realistic fault geometry and rock properties. FaultMod implements fault slip using common nodes, which represent motion common to both sides of the fault, and differential nodes, which represent motion of one side of the fault relative to the other side. We describe how to modify the traction-at-split-nodes method to work with common and differential nodes, using an implicit time stepping algorithm.

A viscoelastic model for dielectric elastomers based on a continuum mechanical formulation and its finite element implementation

NASA Astrophysics Data System (ADS)

Bueschel, A.; Klinkel, S.; Wagner, W.

2011-04-01

Smart materials are active and multifunctional materials, which play an important part for sensor and actuator applications. These materials have the potential to transform passive structures into adaptive systems. However, a prerequisite for the design and the optimization of these materials is, that reliable models exist, which incorporate the interaction between the different combinations of thermal, electrical, magnetic, optical and mechanical effects. Polymeric electroelastic materials, so-called electroactive polymer (EAP), own the characteristic to deform if an electric field is applied. EAP's possesses the benefit that they share the characteristic of polymers, these are lightweight, inexpensive, fracture tolerant, elastic, and the chemical and physical structure is well understood. However, the description "electroactive polymer" is a generic term for many kinds of different microscopic mechanisms and polymeric materials. Based on the laws of electromagnetism and elasticity, a visco-electroelastic model is developed and implemented into the finite element method (FEM). The presented three-dimensional solid element has eight nodes and trilinear interpolation functions for the displacement and the electric potential. The continuum mechanics model contains finite deformations, the time dependency and the nearly incompressible behavior of the material. To describe the possible, large time dependent deformations, a finite viscoelastic model with a split of the deformation gradient is used. Thereby the time dependent characteristic of polymeric materials is incorporated through the free energy function. The electromechanical interactions are considered by the electrostatic forces and inside the energy function.

[Sentinel lymph node metastasis in patients with ductal breast carcinoma in situ].

PubMed

Ruvalcaba-Limón, Eva; de Jesús Garduño-Raya, María; Bautista-Piña, Verónica; Trejo-Martínez, Claudia; Maffuz-Aziz, Antonio; Rodríguez-Cuevas, Sergio

2014-01-01

Sentinel lymph node biopsy in patients with ductal carcinoma in situ still controversial, with positive lymph node in range of 1.4-12.5% due occult invasive breast carcinoma in surgical specimen. To know the frequency of sentimel node metastases in patients with ductal carcinoma in situ, identify differences between positive and negative cases. Retrospective study of patients with ductal carcinoma in situ treated with sentinel lymph node biopsy because mastectomy indication, palpable tumor, radiological lesion = 5 cm, non-favorable breast-tumor relation and/or patients whom surgery could affect lymphatic flow drainage. Of 168 in situ carcinomas, 50 cases with ductal carcinoma in situ and sentinel lymph node biopsy were included, with a mean age of 51.6 years, 30 (60%) asymptomatic. The most common symptoms were palpable nodule (18%), nipple discharge (12%), or both (8%). Microcalcifications were common (72%), comedonecrosis pattern (62%), grade-2 histology (44%), and 28% negative hormonal receptors. Four (8%) cases had intra-operatory positive sentinel lymph node and one patient at final histo-pathological study (60% micrometastases, 40% macrometastases), all with invasive carcinoma in surgical specimen. Patients with intra-operatory positive sentinel lymph node where younger (44.5 vs 51 years), with more palpable tumors (50% vs 23.1%), and bigger (3.5 vs 2 cm), more comedonecrosis pattern (75% vs 60.8%), more indifferent tumors (75% vs 39.1%), and less cases with hormonal receptors (50% vs 73.9%), compared with negative sentinel lymph node cases, all these differences without statistic significance. One of each 12 patients with ductal carcinoma in situ had affection in sentinel lymph node, so we recommend continue doing this procedure to avoid second surgeries due the presence of occult invasive carcinoma.

Detection of breast cancer metastasis in sentinel lymph nodes using intra-operative real time GeneSearch BLN Assay in the operating room: results of the Cardiff study.

PubMed

Mansel, Robert E; Goyal, Amit; Douglas-Jones, Anthony; Woods, Victoria; Goyal, Sumit; Monypenny, Ian; Sweetland, Helen; Newcombe, Robert G; Jasani, Bharat

2009-06-01

Intra-operative assessment is not routinely performed in the UK due to poor sensitivity of available methods and overburdened pathology resources. We conducted a prospective clinical feasibility study of the GeneSearch Breast Lymph Node (BLN) Assay (Veridex, LLC, Warren, NJ) to confirm its potential usefulness within the UK healthcare system. In the assay 50% of the lymph node was processed to detect the presence of cytokeratin-19 and mammaglobin mRNA. The assay was calibrated to detect metastases >0.2 mm. Assay results were compared to H&E performed on each face of approximately 2 mm alternating node slabs and 3 additional sections cut at approximately 150 microm interval from each face of the node slab. 124 sentinel lymph nodes were removed from 82 breast cancer patients. The assay correctly identified all 6 patients with sentinel node macrometastases (>2.0 mm), and 2 of 3 patients with sentinel node micrometastases (0.2-2.0 mm). Sentinel lymph nodes in 4 patients were assay positive but histology negative. Two of these four patients had isolated tumor cells seen by histology. The overall concordance with histology was 93.9% (77/82), with sensitivity of 88.9% (8/9, 95% CI 56.5-98%), specificity of 94.6% (69/73, 95% CI 86.7-97.8%), positive predictive value of 66.7% (8/12, 95% CI 39.1-86.2%) and negative predictive value of 98.6% (69/70, 95% CI 92.3-99.7%). The assay was performed in a median time of 32 min (range 26-69 min). Intra-operative assessment of sentinel lymph node can be performed rapidly and accurately using the GeneSearch BLN Assay.

Virulence genes and plasmid profiles in Rhodococcus equi isolates from domestic pigs and wild boars (Sus scrofa) in Brazil.

PubMed

Ribeiro, Márcio Garcia; Takai, Shinji; Guazzelli, Alessandro; Lara, Gustavo Henrique Batista; da Silva, Aristeu Vieira; Fernandes, Marta Catarina; Condas, Larissa Anuska Zeni; Siqueira, Amanda Keller; Salerno, Tatiana

2011-12-01

The virulence genes and plasmid profiles of 23 Rhodococcus equi isolates from 258 lymph nodes from domestic pigs (129 nodes with lesions and 129 without lesions) and 120 lymph nodes from slaughtered wild boars (60 nodes with lesions and 60 without) were characterized. R. equi was obtained from 19 lymph nodes of domestic pigs, 17 with, and two without lesions, and from four lymph nodes with lesions, from wild boars. The 23 isolates were tested for the presence of vapA and vapB genes, responsible for the 15-17 and 20 kDa virulence-associated proteins, respectively, by PCR in order to characterize as virulent (VapA), intermediately virulent (VapB) and avirulent. Plasmid DNAs were isolated and analyzed by digestion with restriction endonucleases to estimate size and compare their polymorphisms. Of the 19 domestic pigs strains, seven (36.8%) were avirulent and 12 (63.2%) were intermediately virulent, with the intermediately virulent isolates being plasmid types 8 (8 isolates), 10 (2 isolates), 1 (1 isolate) and 29 (1 isolate). The plasmid type of four strains isolated from wild boars was also intermediately virulent type 8. None of the domestic pigs and wild boar isolates showed the vapA gene. These findings demonstrate a high occurrence of plasmid type 8 in isolates from pigs and wild boars, and the similarity of plasmid types in the domestic pigs, wild boars and human isolates in Brazil. Copyright © 2010 Elsevier Ltd. All rights reserved.

Methods for analysis of cracks in three-dimensional solids

NASA Technical Reports Server (NTRS)

Raju, I. S.; Newman, J. C., Jr.

1984-01-01

Various analytical and numerical methods used to evaluate the stress intensity factors for cracks in three-dimensional (3-D) solids are reviewed. Classical exact solutions and many of the approximate methods used in 3-D analyses of cracks are reviewed. The exact solutions for embedded elliptic cracks in infinite solids are discussed. The approximate methods reviewed are the finite element methods, the boundary integral equation (BIE) method, the mixed methods (superposition of analytical and finite element method, stress difference method, discretization-error method, alternating method, finite element-alternating method), and the line-spring model. The finite element method with singularity elements is the most widely used method. The BIE method only needs modeling of the surfaces of the solid and so is gaining popularity. The line-spring model appears to be the quickest way to obtain good estimates of the stress intensity factors. The finite element-alternating method appears to yield the most accurate solution at the minimum cost.

Influence of Joint Flexibility on Vibration Analysis of Free-Free Beams

NASA Astrophysics Data System (ADS)

Gunda, Jagadish Babu; Krishna, Y.

2014-12-01

In present work, joint flexibility (or looseness) of the free-free beam is investigated by using a two noded beam finite element formulation with transverse displacement and joint rotations as the degrees of freedom per node at joint location. Flexibility of the joint is primarily represented by means of a rotational spring analogy, where the stiffness of the rotational spring characterizes the looseness of the flexible joint for an applied bending moment. Influence of joint location as well as joint stiffness on modal behavior of first five modes of slender, uniform free-free beams are discussed for various values of non-dimensional rotational spring stiffness parameter. Numerical accuracy of the results obtained from the present finite element formulation are validated by using the commercially available finite element software which shows the confidence gained on the numerical results discussed in the present study.

An unusual 2p-3d-4f heterometallic coordination polymer featuring Ln8Na and Cu8I clusters as nodes

NASA Astrophysics Data System (ADS)

Zhao, Mingjuan; Chen, Shimin; Huang, Yutian; Dan, Youmeng

2017-01-01

A new cluster-based three-dimensional 2p-3d-4f heterometallic framework {[Ho8Na(OH)6Cu16I2(CPT)24](NO3)9(H2O)6(CH3CN)18}n (1, HCPT = 4-(4-carboxyphenyl)-1,2,4 triazole) has been prepared under solvothermal condition by using a custom-designed bifunctional organic ligand. The single-crystal structure analysis reveals that this framework features novel Ln8Na and Cu8I clusters as nodes, these nodes are further connected by the CPT ligands to give rise to a (6,14)-connected network. The magnetic property of this framework has also been investigated.

Comparison of the recovery of Mycobacterium bovis isolates using the BACTEC MGIT 960 system, BACTEC 460 system, and Middlebrook 7H10 and 7H11 solid media.

PubMed

Hines, Nichole; Payeur, Janet B; Hoffman, Lorraine J

2006-05-01

The BACTEC Microbacteria Growth Indicator Tube (MGIT) 960 system was evaluated to determine how it compares with the BACTEC 460 radiometric system and solid media for recovery of Mycobacterium bovis from tissue samples. A total of 506 bovine lymph node samples were collected from abattoirs in the United States and Mexico between November 2003 and September 2004. Processed samples were inoculated into an MGIT 960 tube, BACTEC 460 vial, and Middlebrook 7H10 and Middlebrook 7H11 solid media. Ziehl-Neelsen slides were prepared to check for contaminants and confirm the presence of acid-fast positive bacilli. Samples containing acid-fast bacilli were confirmed as members of the Mycobacterium tuberculosis complex by a nucleic acid assay. Niacin and nitrate biochemical tests were used to distinguish M. bovis from M. tuberculosis isolates. Statistical analyses were performed to compare recovery rate, mean time to detection, contamination rates, as well as pair-wise comparisons in each category. The results showed that the MGIT 960 system had a higher recovery rate of M. bovis (122/129) than did the BACTEC 460 (102/129) and solid media system (96/129). The average time to detection was 15.8 days for the MGIT 960 system, 28.2 days for the BACTEC 460 system, and 43.4 days for solid media. Contamination rates were 6.9% for the MGIT 960 system, 3.4% for the BACTEC 460 system, and 21.7% for solid media. These results indicate the MGIT 960 system can be used as an alternative to the BACTEC 460 system for recovering M. bovis from tissue samples.

Finite element analysis of the valgus knee joint of an obese child.

PubMed

Sun, Jun; Yan, Songhua; Jiang, Yan; Wong, Duo Wai-Chi; Zhang, Ming; Zeng, Jizhou; Zhang, Kuan

2016-12-28

Knee valgus and varus morbidity is at the second top place in children lower limb deformity diseases. It may cause abnormal stress distribution. The magnitude and location of contact forces on tibia plateau during gait cycle have been indicated as markers for risk of osteoarthritis. So far, few studies reported the contact stress and force distribution on tibial plateau of valgus knee of children. To estimate the contact stresses and forces on tibial plateau of an 8-year old obese boy with valgus knee and a 7-year old healthy boy, three-dimensional (3D) finite element (FE) models of their left knee joints were developed. The valgus knee model has 36,897 nodes and 1,65,106 elements, and the normal knee model has 78,278 nodes and 1,18,756 elements. Paired t test was used for the comparison between the results from the 3D FE analysis method and the results from traditional kinematic measurement methods. The p value of paired t test is 0.12. Maximum stresses shifted to lateral plateau in knee valgus children while maximum stresses were on medial plateau in normal knee child at the first peak of vertical GRF of stance phase. The locations of contact centers on medial plateau changed 3.38 mm more than that on lateral plateau, while the locations of contact centers on medial plateau changed 1.22 mm less than that on lateral plateau for healthy child from the first peak to second peak of vertical GRF of stance phase. The paired t test result shows that there is no significant difference between the two methods. The results of FE analysis method suggest that knee valgus malalignment could be the reason for abnormal knee load that may cause knee problems in obese children with valgus knee in the long-term. This study may help to understand biomechanical mechanism of valgus knees of obese children.

Characterization of gut microbiota profiles by disease activity in patients with Crohn's disease using data mining analysis of terminal restriction fragment length polymorphisms.

PubMed

Andoh, Akira; Kobayashi, Toshio; Kuzuoka, Hiroyuki; Tsujikawa, Tomoyuki; Suzuki, Yasuo; Hirai, Fumihito; Matsui, Toshiyuki; Nakamura, Shiro; Matsumoto, Takayuki; Fujiyama, Yoshihide

2014-05-01

The gut microbiota plays a significant role in the pathogenesis of Crohn's disease (CD). In this study, we analyzed the disease activity and associated fecal microbiota profiles in 160 CD patients and 121 healthy individuals. Fecal samples from the CD patients were collected during three different clinical phases, the active (n=66), remission-achieved (n=51) and remission-maintained (n=43) phases. Terminal restriction fragment length polymorphism (T-RFLP) and data mining analysis using the Classification and Regression Tree (C&RT) approach were performed. Data mining provided a decision tree that clearly identified the various subject groups (nodes). The majority of the healthy individuals were divided into Node-5 and Node-8. Healthy subjects comprised 99% of Node-5 (91 of 92) and 84% of Node-8 (21 of 25 subjects). Node-3 was characterized by CD (136 of 160 CD subjects) and was divided into Node-6 and Node-7. Node-6 (n=103) was characterized by subjects in the active phase (n=48; 46%) and remission-achieved phase (n=39; 38%) and Node-7 was characterized by the remission-maintained phase (21 of 37 subjects; 57%). Finally, Node-6 was divided into Node-9 and Node-10. Node-9 (n=78) was characterized by subjects in the active phase (n=43; 55%) and Node-10 (n=25) was characterized by subjects in the remission-maintained phase (n=16; 64%). Differences in the gut microbiota associated with disease activity of CD patients were identified. Thus, data mining analysis appears to be an ideal tool for the characterization of the gut microbiota in inflammatory bowel disease.

Plasma MMP1 and MMP8 expression in breast cancer: Protective role of MMP8 against lymph node metastasis

PubMed Central

Decock, Julie; Hendrickx, Wouter; Vanleeuw, Ulla; Van Belle, Vanya; Van Huffel, Sabine; Christiaens, Marie-Rose; Ye, Shu; Paridaens, Robert

2008-01-01

Background Elevated levels of matrix metalloproteinases have been found to associate with poor prognosis in various carcinomas. This study aimed at evaluating plasma levels of MMP1, MMP8 and MMP13 as diagnostic and prognostic markers of breast cancer. Methods A total of 208 breast cancer patients, of which 21 with inflammatory breast cancer, and 42 healthy controls were included. Plasma MMP1, MMP8 and MMP13 levels were measured using ELISA and correlated with clinicopathological characteristics. Results Median plasma MMP1 levels were higher in controls than in breast cancer patients (3.45 vs. 2.01 ng/ml), while no difference was found for MMP8 (10.74 vs. 10.49 ng/ml). ROC analysis for MMP1 revealed an AUC of 0.67, sensitivity of 80% and specificity of 24% at a cut-off value of 4.24 ng/ml. Plasma MMP13 expression could not be detected. No correlation was found between MMP1 and MMP8 levels. We found a trend of lower MMP1 levels with increasing tumour size (p = 0.07); and higher MMP8 levels with premenopausal status (p = 0.06) and NPI (p = 0.04). The median plasma MMP1 (p = 0.02) and MMP8 (p = 0.007) levels in the non-inflammatory breast cancer patients were almost twice as high as those found in the inflammatory breast cancer patients. Intriguingly, plasma MMP8 levels were positively associated with lymph node involvement but showed a negative correlation with the risk of distant metastasis. Both controls and lymph node negative patients (pN0) had lower MMP8 levels than patients with moderate lymph node involvement (pN1, pN2) (p = 0.001); and showed a trend for higher MMP8 levels compared to patients with extensive lymph node involvement (pN3) and a strong predisposition to distant metastasis (p = 0.11). Based on the hypothesis that blood and tissue protein levels are in reverse association, these results suggest that MMP8 in the tumour may have a protective effect against lymph node metastasis. Conclusion In summary, we observed differences in MMP1 and MMP8 plasma levels between healthy controls and breast cancer patients as well as between breast cancer patients. Interestingly, our results suggest that MMP8 may affect the metastatic behaviour of breast cancer cells through protection against lymph node metastasis, underlining the importance of anti-target identification in drug development. PMID:18366705

Finite element analysis of a bone healing model: 1-year follow-up after internal fixation surgery for femoral fracture.

PubMed

Jiang-Jun, Zhou; Min, Zhao; Ya-Bo, Yan; Wei, Lei; Ren-Fa, Lv; Zhi-Yu, Zhu; Rong-Jian, Chen; Wei-Tao, Yu; Cheng-Fei, Du

2014-03-01

Finite element analysis was used to compare preoperative and postoperative stress distribution of a bone healing model of femur fracture, to identify whether broken ends of fractured bone would break or not after fixation dislodgement one year after intramedullary nailing. Method s: Using fast, personalized imaging, bone healing models of femur fracture were constructed based on data from multi-slice spiral computed tomography using Mimics, Geomagic Studio, and Abaqus software packages. The intramedullary pin was removed by Boolean operations before fixation was dislodged. Loads were applied on each model to simulate a person standing on one leg. The von Mises stress distribution, maximum stress, and its location was observed. Results : According to 10 kinds of display groups based on material assignment, the nodes of maximum and minimum von Mises stress were the same before and after dislodgement, and all nodes of maximum von Mises stress were outside the fracture line. The maximum von Mises stress node was situated at the bottom quarter of the femur. The von Mises stress distribution was identical before and after surgery. Conclusion : Fast, personalized model establishment can simulate fixation dislodgement before operation, and personalized finite element analysis was performed to successfully predict whether nail dislodgement would disrupt femur fracture or not.

NEUTRONIC REACTOR AND FUEL ELEMENT THEREFOR

DOEpatents

Szilard, L.; Young, G.J.

1958-03-01

This patent relates to a reactor design of the type which employs solid fuel elements disposed in channels within the moderator through which channels and around the fuel elements is conveyed a coolant fiuid. The coolant channels are comprised of aluminum tubes extending through a solid moderator such as graphite and the fuel elements are comprised of an elongated solid body of natural uranium jacketed in an aluminum jacket with the ends thereof closed by aluminum caps of substantially greater thickness than the jacket was and in good thermal contact with the fuel material to facilitate the conduction of heat from the central portion of said ends to the coolant surrounding the fuel element to prevent overheating of said central portion.

Simulation of Detecting Damage in Composite Stiffened Panel Using Lamb Waves

NASA Technical Reports Server (NTRS)

Wang, John T.; Ross, Richard W.; Huang, Guo L.; Yuan, Fuh G.

2013-01-01

Lamb wave damage detection in a composite stiffened panel is simulated by performing explicit transient dynamic finite element analyses and using signal imaging techniques. This virtual test process does not need to use real structures, actuators/sensors, or laboratory equipment. Quasi-isotropic laminates are used for the stiffened panels. Two types of damage are studied. One type is a damage in the skin bay and the other type is a debond between the stiffener flange and the skin. Innovative approaches for identifying the damage location and imaging the damage were developed. The damage location is identified by finding the intersection of the damage locus and the path of the time reversal wave packet re-emitted from the sensor nodes. The damage locus is a circle that envelops the potential damage locations. Its center is at the actuator location and its radius is computed by multiplying the group velocity by the time of flight to damage. To create a damage image for estimating the size of damage, a group of nodes in the neighborhood of the damage location is identified for applying an image condition. The image condition, computed at a finite element node, is the zero-lag cross-correlation (ZLCC) of the time-reversed incident wave signal and the time reversal wave signal from the sensor nodes. This damage imaging process is computationally efficient since only the ZLCC values of a small amount of nodes in the neighborhood of the identified damage location are computed instead of those of the full model.

Maximizing the endosonography: The role of contrast harmonics, elastography and confocal endomicroscopy.

PubMed

Seicean, Andrada; Mosteanu, Ofelia; Seicean, Radu

2017-01-07

New technologies in endoscopic ultrasound (EUS) evaluation have been developed because of the need to improve the EUS and EUS-fine needle aspiration (EUS-FNA) diagnostic rate. This paper reviews the principle, indications, main literature results, limitations and future expectations for each of the methods presented. Contrast-enhanced harmonic EUS uses a low mechanical index and highlights slow-flow vascularization. This technique is useful for differentiating solid and cystic pancreatic lesions and assessing biliary neoplasms, submucosal neoplasms and lymph nodes. It is also useful for the discrimination of pancreatic masses based on their qualitative patterns; however, the quantitative assessment needs to be improved. The detection of small solid lesions is better, and the EUS-FNA guidance needs further research. The differentiation of cystic lesions of the pancreas and the identification of the associated malignancy features represent the main indications. Elastography is used to assess tissue hardness based on the measurement of elasticity. Despite its low negative predictive value, elastography might rule out the diagnosis of malignancy for pancreatic masses. Needle confocal laser endomicroscopy offers useful information about cystic lesions of the pancreas and is still under evaluation for use with solid pancreatic lesions of lymph nodes.

DYNA3D, INGRID, and TAURUS: an integrated, interactive software system for crashworthiness engineering

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

Benson, D.J.; Hallquist, J.O.; Stillman, D.W.

1985-04-01

Crashworthiness engineering has always been a high priority at Lawrence Livermore National Laboratory because of its role in the safe transport of radioactive material for the nuclear power industry and military. As a result, the authors have developed an integrated, interactive set of finite element programs for crashworthiness analysis. The heart of the system is DYNA3D, an explicit, fully vectorized, large deformation structural dynamics code. DYNA3D has the following four capabilities that are critical for the efficient and accurate analysis of crashes: (1) fully nonlinear solid, shell, and beam elements for representing a structure, (2) a broad range of constitutivemore » models for representing the materials, (3) sophisticated contact algorithms for the impact interactions, and (4) a rigid body capability to represent the bodies away from the impact zones at a greatly reduced cost without sacrificing any accuracy in the momentum calculations. To generate the large and complex data files for DYNA3D, INGRID, a general purpose mesh generator, is used. It runs on everything from IBM PCs to CRAYS, and can generate 1000 nodes/minute on a PC. With its efficient hidden line algorithms and many options for specifying geometry, INGRID also doubles as a geometric modeller. TAURUS, an interactive post processor, is used to display DYNA3D output. In addition to the standard monochrome hidden line display, time history plotting, and contouring, TAURUS generates interactive color displays on 8 color video screens by plotting color bands superimposed on the mesh which indicate the value of the state variables. For higher quality color output, graphic output files may be sent to the DICOMED film recorders. We have found that color is every bit as important as hidden line removal in aiding the analyst in understanding his results. In this paper the basic methodologies of the programs are presented along with several crashworthiness calculations.« less

Pulmonary Laser Metastasectomy by 1318-nm Neodymium-Doped Yttrium-Aluminum Garnet Laser: A Retrospective Study About Laser Metastasectomy of the Lung.

PubMed

Porrello, Calogero; Gullo, Roberto; Vaglica, Antonino; Scerrino, Gregorio; Salamone, Giuseppe; Licari, Leo; Raspanti, Cristina; Gulotta, Eliana; Gulotta, Gaspare; Cocorullo, Gianfranco

2018-04-01

The lungs are among the first organ affected by remote metastases from many primary tumors. The surgical resection of isolated pulmonary metastases represents an important and effective element of therapy. This is a retrospective study about our entire experience with pulmonary resection for metastatic cancer using 1318-nm neodymium-doped yttrium-aluminum garnet laser. In this single-institution study, we retrospectively analyzed a group of 209 patients previously treated for primary malignant solid tumors. We excluded 103 patients. The number and location of lesions in the lungs was determined using chest computed tomography and positron emission tomography-computed tomography. Disseminated malignancy was excluded. All pulmonary laser resections are performed via an anteroaxillary muscle-sparing thoracotomy. All lesions were routinely removed by laser with a small (5-10 mm) margin of the healthy lung. Patients received systematic lymph node sampling with intraoperative smear cytology of sampled lymph nodes. Mortality at 2 years from the first surgery is around 20% (10% annually). This value increases to 45% in the third year. The estimated median survival for patients who underwent the first surgery is reported to be approximately 42 months. Our results show that laser resection of lung metastases can achieve good result, in terms of radical resection and survival, as conventional surgical metastasectomy. The great advantage is the possibility of limiting the damage to the lung. Stapler resection of a high number of metastases would mutilate the lung.

The effects of minor elements in La0.6Sr0.4Co0.2Fe0.8O3-δ cathodes on oxygen reduction reaction

NASA Astrophysics Data System (ADS)

Oishi, Junya; Otomo, Junichiro; Oshima, Yoshito; Koyama, Michihisa

2015-03-01

It is known that the minor elements affect the performance of solid oxide fuel cell (SOFC). In this study, we focus on the influence of minor elements on the SOFC cathode properties. The Ca, Ba, Al, and Si, which originate from raw materials and production processes for SOFC cathodes, are investigated as minor elements that may have effect on the properties of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathode. To examine the effects of minor elements on the cathode properties, Ca, Ba, Al, and Si with a controlled concentration are added to the LSCF reference sample. Conductivity relaxation measurements are conducted to determine the chemical diffusion coefficient (Dchem) and surface exchange coefficient (ktr), which governs the overpotential characteristics of the LSCF cathode. The results show that Al and Si have negative effects on both Dchem and ktr while Ca and Ba do not alter Dchem and show weakly positive effects on ktr. The effects of Ca and Ba for the cathode properties are discussed on the basis of XPS measurements.

KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility look over paperwork during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by the National Space Development Agency of Japan (NASDA), is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

NASA Image and Video Library

2003-09-03

KENNEDY SPACE CENTER, FLA. - Workers in the Space Station Processing Facility look over paperwork during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by the National Space Development Agency of Japan (NASDA), is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi, with the National Space Development Agency of Japan (NASDA), works at a console during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

NASA Image and Video Library

2003-09-03

KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi, with the National Space Development Agency of Japan (NASDA), works at a console during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM). Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 attaches to the end of the U.S. Lab on the ISS and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments.

Coexistence between renal cell cancer and Hodgkin's lymphoma: A rare coincidence

PubMed Central

Jimenez I, Victor H

2006-01-01

Background Renal cell carcinoma is the most common kidney tumor in adults and accounts for approximately 3% of adult malignancies. An increased incidence of second malignancies has been well documented in a number of different disorders, such as head and neck tumors, and hairy cell leukemia. In addition, treatment associated second malignancies (usually leukemias and lymphomas but also solid tumors) have been described in long term survivors of Hodgkin's lymphoma (HL), Non Hodgkin's lymphoma and in various pediatric tumors. Case presentation We present the case of a 66 year-old woman with abdominal pain and dyspnea. We performed a thorax CT scan that showed lymph nodes enlargement and subsequently by presence of abdominal pain was performed an abdominal and pelvis CT scan that showed a right kidney tumor of 4 × 5 cms besides of abdominal lymph nodes enlargement. A radical right nephrectomy was designed and Hodgkin's lymphoma was diagnosed in the abdominal lymph nodes while renal cell tumor exhibited a renal cell cancer. Patient received EVA protocol achieving complete response. Conclusion We described the first case reported in the medical literature of the coexistence between Hodgkin's lymphoma and renal cell cancer. Previous reports have shown the relationship of lymphoid neoplasms with solid tumors, but they have usually described secondary forms of cancer related to chemotherapy. PMID:16549035

LGS adaptive optics system with long-pulsed sodium laser on Lijiang 1.8 meter telescope 2014-2016 observation campaign

NASA Astrophysics Data System (ADS)

Wei, Kai; Li, Min; Jiang, Changchun; Wei, Ling; Zheng, Wenjia; Li, Wenru; Ma, Xiaoyu; Zhou, Luchun; Jin, Kai; Bo, Yong; Zuo, Junwei; Wang, Pengyuan; Cheng, Feng; Zhang, Xiaojun; Chen, Donghong; Deng, Jijiang; Gao, Yang; Shen, Yu; Bian, Qi; Yao, Ji; Huang, Jiang; Dong, Ruoxi; Deng, Keran; Peng, Qinjun; Rao, Changhui; Xu, Zuyan; Zhang, Yudong

2016-07-01

During 2014-2016, the Laser guide star (LGS) adaptive optics (AO) system observation campaign has been carried out on Lijiang 1.8 meter telescope. During the campaign, two generation LGS AO systems have been developed and installed. In 2014, a long-pulsed solid Sodium prototype laser with 20W@400Hz, a beam transfer optical (BTO) system, and a laser launch telescope (LLT) with 300mm diameter were mounted onto the telescope and moved with telescope azimuth journal. At the same time, a 37-elements compact LGS AO system had been mounted on the Bent-Cassegrain focus and got its first light on observing HIP43963 (mV= 8.18mv) and reached Sr=0.27 in J Band after LGS AO compensation. In 2016, the solid Sodium laser has been upgrade to stable 32W@800Hz while D2a plus D2b repumping is used to increase the photon return, and a totally new LGS AO system with 164-elements Deformable Mirror, Linux Real Time Controller, inner closed loop Tip/tilt mirror, Multiple-PMT tracking detector is established and installed on the telescope. And the throughput for the BTO/LLT is improved nearly 20%. The campaign process, the performance of the two LGS AO systems especially the latter one, the characteristics of the BTO/LLT system and the result are present in this paper.

Entanglement distillation between solid-state quantum network nodes.

PubMed

Kalb, N; Reiserer, A A; Humphreys, P C; Bakermans, J J W; Kamerling, S J; Nickerson, N H; Benjamin, S C; Twitchen, D J; Markham, M; Hanson, R

2017-06-02

The impact of future quantum networks hinges on high-quality quantum entanglement shared between network nodes. Unavoidable imperfections necessitate a means to improve remote entanglement by local quantum operations. We realize entanglement distillation on a quantum network primitive of distant electron-nuclear two-qubit nodes. The heralded generation of two copies of a remote entangled state is demonstrated through single-photon-mediated entangling of the electrons and robust storage in the nuclear spins. After applying local two-qubit gates, single-shot measurements herald the distillation of an entangled state with increased fidelity that is available for further use. The key combination of generating, storing, and processing entangled states should enable the exploration of multiparticle entanglement on an extended quantum network. Copyright © 2017, American Association for the Advancement of Science.

Detection of ALK translocation in non-small cell lung carcinoma (NSCLC) and its clinicopathological significance using the Ventana immunohistochemical staining method: a single-center large-scale investigation of 1, 504 Chinese Han patients

PubMed Central

Yang, Lin; Ling, Yun; Guo, Lei; Ma, Di; Xue, Xuemin; Wang, Bingning; Li, Junling; Ying, Jianming

2016-01-01

Objective The novel fully automated immunohistochemistry (IHC) assay-Ventana anaplastic lymphoma kinase (ALK)-D5F3 for screening ALK rearrangements has been approved by China’s Food and Drug Administration in 2013, our previous study disclosed a highly specificity and sensitivity nearly 100%, and its efficacy needs to be evaluated in a large cohort of primary lung adenocarcinoma patients, and to compare clinicopathological features with ALK (+) and ALK (-) lung adenocarcinoma. Methods A total of 1,504 consecutive surgical lung adenocarcinoma cases of Chinese Han population were collected and re-diagnosed according to the 2011 multidisciplinary classification of lung adenocarcinoma. Fully automated Ventana ALK-D5F3 IHC staining with a binary scoring was adopted to evaluate staining and correlated with clinicopathological characters, including age, sex, differentiation degree, histological subtype, lymph node metastasis, and clinical staging. ALK (+) patients were followed-up, and targeted therapy of ALK-inhibitors was adopted and observed in patients with stage IV according to the NCCN guideline. Results ALK positive adenocarcinomas were identified in 6.6% of the surgically resected 1,504 NSCLCs, and significantly younger than the negative group (P<0.05).Mucinous adenocarcinoma (28.2%) was determined to be predominant in ALK (+) cases, followed by the solid type (11.7%), specific type (6.8%), papillary type (5.6%), acinar type (5.5%), and lepidic type (3.1%), and the differences were statistically significant (χ2=42.011, P<0.05). ALK (+) adenocarcinoma with lymph node metastasis (10.8%) were significantly higher than that without lymph node metastasis (4.5%) (χ2=19.809, P<0.05); and ALK (+) in phase IV (20%) was significantly higher than phase III (12.9%), phase II (4.2%), phase I (4.5%), and phase 0 (0) (χ2=36.068, P<0.05). Multivariate logistic regression disclosed that patient age, AJCC staging, and histological mucinous subtype were correlated with ALK positive staining (OR=0.959, 1.578, 5.036, respectively). Sixty eight patients had followed-up results, five patients out of which primarily diagnosed or progressed into Stage IV benefited well from targeted therapy with Crizotinib. Conclusions The ALK fusion protein was seen in 6.6% Chinese NSCLC patients, and mostly seen in younger, clinically higher staging, mucinous and solid predominant adenocarcinoma. Clinical trials in patients of Stage IV confirmed that ALK-D5F3 Ventana IHC is serviceable in screening ALK-positive candidates for molecular targeted therapy. PMID:27877008

Detection of ALK translocation in non-small cell lung carcinoma (NSCLC) and its clinicopathological significance using the Ventana immunohistochemical staining method: a single-center large-scale investigation of 1, 504 Chinese Han patients.

PubMed

Yang, Lin; Ling, Yun; Guo, Lei; Ma, Di; Xue, Xuemin; Wang, Bingning; Li, Junling; Ying, Jianming

2016-10-01

The novel fully automated immunohistochemistry (IHC) assay-Ventana anaplastic lymphoma kinase (ALK)-D5F3 for screening ALK rearrangements has been approved by China's Food and Drug Administration in 2013, our previous study disclosed a highly specificity and sensitivity nearly 100%, and its efficacy needs to be evaluated in a large cohort of primary lung adenocarcinoma patients, and to compare clinicopathological features with ALK (+) and ALK (-) lung adenocarcinoma. A total of 1,504 consecutive surgical lung adenocarcinoma cases of Chinese Han population were collected and re-diagnosed according to the 2011 multidisciplinary classification of lung adenocarcinoma. Fully automated Ventana ALK-D5F3 IHC staining with a binary scoring was adopted to evaluate staining and correlated with clinicopathological characters, including age, sex, differentiation degree, histological subtype, lymph node metastasis, and clinical staging. ALK (+) patients were followed-up, and targeted therapy of ALK-inhibitors was adopted and observed in patients with stage IV according to the NCCN guideline. ALK positive adenocarcinomas were identified in 6.6% of the surgically resected 1,504 NSCLCs, and significantly younger than the negative group (P<0.05).Mucinous adenocarcinoma (28.2%) was determined to be predominant in ALK (+) cases, followed by the solid type (11.7%), specific type (6.8%), papillary type (5.6%), acinar type (5.5%), and lepidic type (3.1%), and the differences were statistically significant (χ 2 =42.011, P<0.05). ALK (+) adenocarcinoma with lymph node metastasis (10.8%) were significantly higher than that without lymph node metastasis (4.5%) (χ 2 =19.809, P<0.05); and ALK (+) in phase IV (20%) was significantly higher than phase III (12.9%), phase II (4.2%), phase I (4.5%), and phase 0 (0) (χ 2 =36.068, P<0.05). Multivariate logistic regression disclosed that patient age, AJCC staging, and histological mucinous subtype were correlated with ALK positive staining (OR=0.959, 1.578, 5.036, respectively). Sixty eight patients had followed-up results, five patients out of which primarily diagnosed or progressed into Stage IV benefited well from targeted therapy with Crizotinib. The ALK fusion protein was seen in 6.6% Chinese NSCLC patients, and mostly seen in younger, clinically higher staging, mucinous and solid predominant adenocarcinoma. Clinical trials in patients of Stage IV confirmed that ALK-D5F3 Ventana IHC is serviceable in screening ALK-positive candidates for molecular targeted therapy.

Multifunctional Polymer Microbubbles for Advanced Sentinel Lymph Node Imaging and Mapping

DTIC Science & Technology

2012-06-01

of thiolated poly(acrylic acid) with fluorescein attached. (b) Bright field image of large bubbles stabilized by polymer and phospholipid...Page 1 of 6 AD_________________ Award Number: W81XWH-11-1-0215 TITLE:   Multifunctional Polymer Microbubbles for Advanced... Polymer Microbubbles for Advanced Sentinel Lymph Node Imaging and Mapping 5b. GRANT NUMBER W81XWH-11-1-0215   5c. PROGRAM ELEMENT NUMBER 6

A Micromechanics Finite Element Model for Studying the Mechanical Behavior of Spray-On Foam Insulation (SOFI)

NASA Technical Reports Server (NTRS)

Ghosn, Louis J.; Sullivan, Roy M.; Lerch, Bradley A.

2006-01-01

A micromechanics model has been constructed to study the mechanical behavior of spray-on foam insulation (SOFI) for the external tank. The model was constructed using finite elements representing the fundamental repeating unit of the SOFI microstructure. The details of the micromechanics model were based on cell observations and measured average cell dimensions discerned from photomicrographs. The unit cell model is an elongated Kelvin model (fourteen-sided polyhedron with 8 hexagonal and six quadrilateral faces), which will pack to a 100% density. The cell faces and cell edges are modeled using three-dimensional 20-node brick elements. Only one-eighth of the cell is modeled due to symmetry. By exercising the model and correlating the results with the macro-mechanical foam behavior obtained through material characterization testing, the intrinsic stiffness and Poisson s Ratio of the polymeric cell walls and edges are determined as a function of temperature. The model is then exercised to study the unique and complex temperature-dependent mechanical behavior as well as the fracture initiation and propagation at the microscopic unit cell level.

Optimizing treatment for children and adolescents with papillary thyroid carcinoma in post-Chernobyl exposed region: The roles of lymph node dissections in the central and lateral neck compartments.

PubMed

Fridman, Mikhail; Krasko, Olga; Lam, Alfred King-Yin

2018-06-01

There is lack of data to predict lymph node metastases in pediatric thyroid cancer. The aims are to study (1) the factors affecting the lymph node metastases in children and adolescence with papillary thyroid carcinoma in region exposed to radiation and (2) to evaluate the predictive significance of these factors for lateral compartment lymphadenectomy. Five hundred and nine patients with papillary thyroid carcinoma underwent total thyroidectomy and lymph nodes resection (central and lateral compartments of the neck) surgery during the period of 1991-2010 in Belarus were recruited. The factors related to lymph node metastases were studied in these patients. In the patients with papillary thyroid carcinoma, increase number of cancer-positive lymph nodes in the central neck compartment were associated with a risk to develop lateral nodal disease as well as bilateral nodal disease. Futhermore, positive lateral compartment nodal metastases are associated with age and gender of the patients, tumour size, minimal extra-thyroidal extension, solid architectonic, extensive desmoplasia in carcinoma, presence of psammoma bodies, extensive involvement of the thyroid and metastatic ratio index revealed after examination of the central cervical chain lymph nodes. The presence of nodal disease, degree of lymph node involvement and the distribution of lymph node metastases significantly increase the recurrence rates of patients with papillary thyroid carcinoma. To conclude, the lymph nodes metastases in young patients with papillary thyroid carcinoma in post-Chernobyl exposed region are common and the pattern could be predicted by many clinical and pathological factors. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

Finite element meshing of ANSYS (trademark) solid models

NASA Technical Reports Server (NTRS)

Kelley, F. S.

1987-01-01

A large scale, general purpose finite element computer program, ANSYS, developed and marketed by Swanson Analysis Systems, Inc. is discussed. ANSYS was perhaps the first commercially available program to offer truly interactive finite element model generation. ANSYS's purpose is for solid modeling. This application is briefly discussed and illustrated.

Sentinel node detection in cervical cancer with (99m)Tc-phytate.

PubMed

Silva, Lucas B; Silva-Filho, Agnaldo L; Traiman, Paulo; Triginelli, Sérgio A; de Lima, Carla Flávia; Siqueira, Cristiano Ferrari; Barroso, Adelanir; Rossi, Telma Maria F F; Pedrosa, Moises Salgado; Miranda, Dairton; Melo, José Renan Cunha

2005-05-01

The aim of this study was to investigate the feasibility of sentinel lymph node (SLN) identification using radioisotopic lymphatic mapping with technetium-99 m-labeled phytate in patients undergoing radical hysterectomy with pelvic lymphadenectomy for treatment of early cervical cancer. Between July 2001 and February 2003, 56 patients with cervical cancer FIGO stage I (n = 53) or stage II (n = 3) underwent sentinel lymph node detection with preoperative lymphoscintigraphy ((99m)Tc-labeled phytate injected into the uterine cervix, at 3, 6, 9, and 12 o'clock, at a dose of 55-74 MBq in a volume of 0.8 ml) and intraoperative lymphatic mapping with a handheld gamma probe. Radical hysterectomy was aborted in three cases because parametrial invasion was found intraoperatively and we performed only sentinel node resection. The remaining 53 patients underwent radical hysterectomy with complete pelvic lymphadenectomy. Sentinel nodes were detected using a handheld gamma-probe and removed for pathological assessment during the abdominal radical hysterectomy and pelvic lymphadenectomy. One or more sentinel nodes were detected in 52 out of 56 eligible patients (92.8%). A total of 120 SLNs were detected by lymphoscintigraphy (mean 2.27 nodes per patient) and intraoperatively by gamma probe. Forty-four percent of SLNs were found in the external iliac area, 39% in the obturator region, 8.3% in interiliac region, and 6.7% in the common iliac area. Unilateral sentinel nodes were found in thirty-one patients (59%). The remaining 21 patients (41%) had bilateral sentinel nodes. Microscopic nodal metastases were confirmed in 17 (32%) cases. In 10 of these patients, only SLNs had metastases. The 98 sentinel nodes that were negative on hematoxylin and eosin were submitted to cytokeratin immunohistochemical analysis. Five (5.1%) micrometastases were identified with this technique. The sensitivity of the sentinel node was 82.3% (CI 95% = 56.6-96.2) and the negative predictive value was 92.1% (CI 95% = 78.6-98.3). The accuracy of sentinel node in predicting the lymph node status was 94.2%. Preoperative lymphoscintigraphy and intraoperative lymphatic mapping with (99m)Tc-labeled phytate are effective in identifying sentinel nodes in patients undergoing radical hysterectomy and to select women in whom lymph node dissection can be avoided.

Trace element abundances in single presolar silicon carbide grains by synchrotron X-ray fluorescence

NASA Astrophysics Data System (ADS)

Kashiv, Yoav

2004-12-01

Synchrotron x-ray fluorescence (SXRF) was applied to the study of presolar grains for the first time in this study. 41 single SiC grains of the KJF size fraction (mass-weighted median size of 1.86 μm) from the Murchison (CM2) Meteorite were analyzed. The absolute abundances of the following elements were determined (not every element in every grain): S, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Sr, Y, Zr, Nb, Mo, Ru, Os, Ir and Pt (underlined elements were detected here for the first time in single grains). There is good agreement between the heavier trace element abundances in the grains and s-process nucleosynthesis calculations. It suggests that smaller 13C pocket sizes are needed in the parent stars, a free parameter in the stellar models, than is deduced from isotopic analyses of s-, and s-mainly, elements, such as Zr and Mo. In addition, the data confirms the radiogenic nature of the Nb in the grains, due to the in situ decay of 93Zr (t 1/2 = 1.5 × 106 year). The data suggest that the trace elements condensed into the host SiC grains by a combination of condensation in solid solution and incorporation of subgrains. It seems that many of the trace elements reside mainly in subgrains of two solid solution: (1)a TiC based solid solution, and (2)a Mo-Ru carbide based solid solution. The presence of subgrains of an Fe-Ni alloy solid solution is suggested as well. Subgrains of all 3 solid solutions were observed previously in presolar graphite grains.* *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Adobe Acrobat.

The posterior cervical lymph node in toxoplasmosis.

PubMed

Gray, G F; Kimball, A C; Kean, B H

1972-11-01

Posterior cervical node enlargement is characteristic of clinical toxoplasmosis in adults. Lymph node biopsies from 37 patients, who were tested for toxoplasmosis by serologic and isolation studies, were examined. A characteristic pattern of sinus histiocytosis was seen in 17 of 18 posterior cervical nodes and in only 1 of 4 lymph nodes from other sites from patients with toxoplasmosis. The characteristic pattern was not seen in posterior cervical nodes or in lymph nodes from other sites from patients with other diseases. Lymphoma obscured the characteristic changes of toxoplasmosis in the posterior cervical nodes and other nodes of 5 patients with these coexisting diseases. Organisms were seen in tissue sections in only 2 instances. T gondii was isolated from mice in 14 of 17 attempts using nodes from patients with toxoplasmosis, but from none of 8 attempts using nodes from patients with other diseases.

Diamond photonics for distributed quantum networks

NASA Astrophysics Data System (ADS)

Johnson, Sam; Dolan, Philip R.; Smith, Jason M.

2017-09-01

The distributed quantum network, in which nodes comprising small but well-controlled quantum states are entangled via photonic channels, has in recent years emerged as a strategy for delivering a range of quantum technologies including secure communications, enhanced sensing and scalable quantum computing. Colour centres in diamond are amongst the most promising candidates for nodes fabricated in the solid-state, offering potential for large scale production and for chip-scale integrated devices. In this review we consider the progress made and the remaining challenges in developing diamond-based nodes for quantum networks. We focus on the nitrogen-vacancy and silicon-vacancy colour centres, which have demonstrated many of the necessary attributes for these applications. We focus in particular on the use of waveguides and other photonic microstructures for increasing the efficiency with which photons emitted from these colour centres can be coupled into a network, and the use of microcavities for increasing the fraction of photons emitted that are suitable for generating entanglement between nodes.

Elemental Fluorine Based Syntheses of Pentafluoro Phenly and other Aromatic Perfluoropolyether Polymers

DTIC Science & Technology

1994-01-31

ECM 300 PA. 13.8 Pe: -1.0 SCALE $000 00 MZ/o• 14.7171 Pe•/CM 50 0 -50 -100 -150 -200 PPM 3 Very unusual perfluoro polyketone structures have beeni...11PIA C14 LI) LL. L)V LLL cim C45 We think the zeolitic solid state structure of this very interesting perfluoro polyketone is most unusual and there

Crystal growth of argyrodite-type phases Cu 8-xGeS 6-xI x and Cu 8-xGeSe 6-xI x (0⩽ x⩽0.8)

NASA Astrophysics Data System (ADS)

Tomm, Yvonne; Schorr, Susan; Fiechter, Sebastian

2008-04-01

The growth of single crystalline argyrodites of type Cu 8-xGeX 6-xY x ( X=S, Se; Y=I) is reported. These materials undergo solid-solid phase transitions at temperatures ranging from 30 to 90 °C. In the high temperature phase, Cu 8GeS 6 crystallizes in the cubic space group F4¯3m. In the low temperature phase, the compound is present in the orthorhombic space group Pmn2 1. Cu 8GeSe 6 appears exclusively in the hexagonal space groups P6 3mc or P6 3cm, respectively. Single crystals of these argyrodites were obtained by chemical vapor transport in a temperature gradient Δ T=980-950 and Δ T=700-620 °C for sulfides and selenides, respectively. As a result of the growth process, the high temperature phase remains stable even at ambient temperature by incorporation of the transport agent iodine during the growth process. As determined by energy dispersive X-ray analysis (EDAX), the composition of the sulfide crystals grown ranges from Cu 8GeS 6 to Cu 7.16GeS 5.16I 0.84. The selenide crystallizes as Cu 7.69GeSe 5.69I 0.31. In contrast, the solid state reaction of the elements Cu, Ge and X produces a material in the low temperature modification with an ideal composition of Cu 8GeX 6.

Mesh Deformation Based on Fully Stressed Design: The Method and Two-Dimensional Examples

NASA Technical Reports Server (NTRS)

Hsu, Su-Yuen; Chang, Chau-Lyan

2007-01-01

Mesh deformation in response to redefined boundary geometry is a frequently encountered task in shape optimization and analysis of fluid-structure interaction. We propose a simple and concise method for deforming meshes defined with three-node triangular or four-node tetrahedral elements. The mesh deformation method is suitable for large boundary movement. The approach requires two consecutive linear elastic finite-element analyses of an isotropic continuum using a prescribed displacement at the mesh boundaries. The first analysis is performed with homogeneous elastic property and the second with inhomogeneous elastic property. The fully stressed design is employed with a vanishing Poisson s ratio and a proposed form of equivalent strain (modified Tresca equivalent strain) to calculate, from the strain result of the first analysis, the element-specific Young s modulus for the second analysis. The theoretical aspect of the proposed method, its convenient numerical implementation using a typical linear elastic finite-element code in conjunction with very minor extra coding for data processing, and results for examples of large deformation of two-dimensional meshes are presented in this paper. KEY WORDS: Mesh deformation, shape optimization, fluid-structure interaction, fully stressed design, finite-element analysis, linear elasticity, strain failure, equivalent strain, Tresca failure criterion

Perspectives of advanced thermal management in solar thermochemical syngas production using a counter-flow solid-solid heat exchanger

NASA Astrophysics Data System (ADS)

Falter, Christoph; Sizmann, Andreas; Pitz-Paal, Robert

2017-06-01

A modular reactor model is presented for the description of solar thermochemical syngas production involving counter-flow heat exchangers that recuperate heat from the solid phase. The development of the model is described including heat diffusion within the reactive material as it travels through the heat exchanger, which was previously identified to be a possibly limiting factor in heat exchanger design. Heat transfer within the reactive medium is described by conduction and radiation, where the former is modeled with the three-resistor model and the latter with the Rosseland diffusion approximation. The applicability of the model is shown by the analysis of heat exchanger efficiency for different material thicknesses and porosities in a system with 8 chambers and oxidation and reduction temperatures of 1000 K and 1800 K, respectively. Heat exchanger efficiency is found to rise strongly for a reduction of material thickness, as the element mass is reduced and a larger part of the elements takes part in the heat exchange process. An increase of porosity enhances radiation heat exchange but deteriorates conduction. The overall heat exchange in the material is improved for high temperatures in the heat exchanger, as radiation dominates the energy transfer. The model is shown to be a valuable tool for the development and analysis of solar thermochemical reactor concepts involving heat exchange from the solid phase.

Control of microstructure and mechanical properties of laser solid formed Inconel 718 superalloy by electromagnetic stirring

NASA Astrophysics Data System (ADS)

Liu, Fencheng; Cheng, Hongmao; Yu, Xiaobin; Yang, Guang; Huang, Chunping; Lin, Xin; Chen, Jing

2018-02-01

The coarse columnar grains and special interface in laser solid formed (LSFed) Inconel 718 superalloy workpieces seriously affect their mechanical properties. To improve the microstructure and mechanical properties of LSFed Inconel 718 superalloy, electromagnetic stirring (EMS) was introduced to alter the solidification process of the molten pool during LSF. The results show that EMS could not completely eliminate the epitaxially growing columnar grains, however, the strong convection of liquid metals can effectively influence the solid-liquid interface growing mode. The segregation of alloying elements on the front of solid-liquid interface is inhibited and the degree of constitutional supercooling decreases correspondingly. Comparing the microstructures of samples formed under different process parameters, the size and amount of the γ+Laves eutectic phases formed in interdendritic area decrease along with the increasing magnetic field intensity, resulting in more uniformly distributed alloying elements. The residual stress distribution is proved to be more uniform, which is beneficial to the grain refinement after recrystallilzaiton. Mechanical properties testing results show an improvement of 100 MPa in tensile strength and 22% in elongation was obtained after EMS was used. The high cycle fatigue properties at room temperature was also improved from 4.09 × 104 cycles to 8.21 × 104 cycles for the as-deposited samples, and from 5.45 × 104 cycles to 12.73 × 104 cycles for the heat treated samples respectively.

A finite element study on the mechanical response of the head-neck interface of hip implants under realistic forces and moments of daily activities: Part 1, level walking.

PubMed

Farhoudi, Hamidreza; Fallahnezhad, Khosro; Oskouei, Reza H; Taylor, Mark

2017-11-01

This paper investigates the mechanical response of a modular head-neck interface of hip joint implants under realistic loads of level walking. The realistic loads of the walking activity consist of three dimensional gait forces and the associated frictional moments. These forces and moments were extracted for a 32mm metal-on-metal bearing couple. A previously reported geometry of a modular CoCr/CoCr head-neck interface with a proximal contact was used for this investigation. An explicit finite element analysis was performed to investigate the interface mechanical responses. To study the level of contribution and also the effect of superposition of the load components, three different scenarios of loading were studied: gait forces only, frictional moments only, and combined gait forces and frictional moments. Stress field, micro-motions, shear stresses and fretting work at the contacting nodes of the interface were analysed. Gait forces only were found to significantly influence the mechanical environment of the head-neck interface by temporarily extending the contacting area (8.43% of initially non-contacting surface nodes temporarily came into contact), and therefore changing the stress field and resultant micro-motions during the gait cycle. The frictional moments only did not cause considerable changes in the mechanical response of the interface (only 0.27% of the non-contacting surface nodes temporarily came into contact). However, when superposed with the gait forces, the mechanical response of the interface, particularly micro-motions and fretting work, changed compared to the forces only case. The normal contact stresses and micro-motions obtained from this realistic load-controlled study were typically in the range of 0-275MPa and 0-38µm, respectively. These ranges were found comparable to previous experimental displacement-controlled pin/cylinder-on-disk fretting corrosion studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Deformation in Micro Roll Forming of Bipolar Plate

NASA Astrophysics Data System (ADS)

Zhang, P.; Pereira, M.; Rolfe, B.; Daniel, W.; Weiss, M.

2017-09-01

Micro roll forming is a new processing technology to produce bipolar plates for Proton Exchange Membrane Fuel Cells (PEMFC) from thin stainless steel foil. To gain a better understanding of the deformation of the material in this process, numerical studies are necessary before experimental implementation. In general, solid elements with several layers through the material thickness are required to analyse material thinning in processes where the deformation mode is that of bending combined with tension, but this results in high computational costs. This pure solid element approach is especially time-consuming when analysing roll forming processes which generally involves feeding a long strip through a number of successive roll stands. In an attempt to develop a more efficient modelling approach without sacrificing accuracy, two solutions are numerically analysed with ABAQUS/Explicit in this paper. In the first, a small patch of solid elements over the strip width and in the centre of the “pre-cut” sheet is coupled with shell elements while in the second approach pure shell elements are used to discretize the full sheet. In the first approach, the shell element enables accounting for the effect of material being held in the roll stands on material flow while solid elements can be applied to analyse material thinning in a small discrete area of the sheet. Experimental micro roll forming trials are performed to prove that the coupling of solid and shell elements can give acceptable model accuracy while using shell elements alone is shown to result in major deviations between numerical and experimental results.

A mixed shear flexible finite element for the analysis of laminated plates

NASA Technical Reports Server (NTRS)

Putcha, N. S.; Reddy, J. N.

1984-01-01

A mixed shear flexible finite element based on the Hencky-Mindlin type shear deformation theory of laminated plates is presented and their behavior in bending is investigated. The element consists of three displacements, two rotations, and three moments as the generalized degrees of freedom per node. The numerical convergence and accuracy characteristics of the element are investigated by comparing the finite element solutions with the exact solutions. The present study shows that reduced-order integration of the stiffness coefficients due to shear is necessary to obtain accurate results for thin plates.

Dragon Ears airborne acoustic array: CSP analysis applied to cross array to compute real-time 2D acoustic sound field

NASA Astrophysics Data System (ADS)

Cerwin, Steve; Barnes, Julie; Kell, Scott; Walters, Mark

2003-09-01

This paper describes development and application of a novel method to accomplish real-time solid angle acoustic direction finding using two 8-element orthogonal microphone arrays. The developed prototype system was intended for localization and signature recognition of ground-based sounds from a small UAV. Recent advances in computer speeds have enabled the implementation of microphone arrays in many audio applications. Still, the real-time presentation of a two-dimensional sound field for the purpose of audio target localization is computationally challenging. In order to overcome this challenge, a crosspower spectrum phase1 (CSP) technique was applied to each 8-element arm of a 16-element cross array to provide audio target localization. In this paper, we describe the technique and compare it with two other commonly used techniques; Cross-Spectral Matrix2 and MUSIC3. The results show that the CSP technique applied to two 8-element orthogonal arrays provides a computationally efficient solution with reasonable accuracy and tolerable artifacts, sufficient for real-time applications. Additional topics include development of a synchronized 16-channel transmitter and receiver to relay the airborne data to the ground-based processor and presentation of test data demonstrating both ground-mounted operation and airborne localization of ground-based gunshots and loud engine sounds.

Carbon under extreme conditions: phase boundaries and electronic properties from first-principles theory.

PubMed

Correa, Alfredo A; Bonev, Stanimir A; Galli, Giulia

2006-01-31

At high pressure and temperature, the phase diagram of elemental carbon is poorly known. We present predictions of diamond and BC8 melting lines and their phase boundary in the solid phase, as obtained from first-principles calculations. Maxima are found in both melting lines, with a triple point located at approximately 850 GPa and approximately 7,400 K. Our results show that hot, compressed diamond is a semiconductor that undergoes metalization upon melting. In contrast, in the stability range of BC8, an insulator to metal transition is likely to occur in the solid phase. Close to the diamond/liquid and BC8/liquid boundaries, molten carbon is a low-coordinated metal retaining some covalent character in its bonding up to extreme pressures. Our results provide constraints on the carbon equation of state, which is of critical importance for devising models of Neptune, Uranus, and white dwarf stars, as well as of extrasolar carbon-rich planets.

Carbon under extreme conditions: Phase boundaries and electronic properties from first-principles theory

DOE PAGES

Correa, Alfredo A.; Bonev, Stanimir A.; Galli, Giulia

2006-01-23

At high pressure and temperature, the phase diagram of elemental carbon is poorly known. We present predictions of diamond and BC8 melting lines and their phase boundary in the solid phase, as obtained from first-principles calculations. Maxima are found in both melting lines, with a triple point located at ≈ 850 GPa and ≈ 7,400 K. Our results show that hot, compressed diamond is a semiconductor that undergoes metalization upon melting. In contrast, in the stability range of BC8, an insulator to metal transition is likely to occur in the solid phase. Close to the diamond/liquid and BC8/liquid boundaries, moltenmore » carbon is a low-coordinated metal retaining some covalent character in its bonding up to extreme pressures. Lastly, our results provide constraints on the carbon equation of state, which is of critical importance for devising models of Neptune, Uranus, and white dwarf stars, as well as of extrasolar carbon-rich planets.« less

KSC-97PC1138

NASA Image and Video Library

1997-07-26

International Space Station (ISS) contractors erect access scaffolding around the Pressurized Mating Adapter-1 (PMA-1) for the ISS in KSC’s Space Station Processing Facility. A PMA is a cone-shaped connector that will be attached to Node 1, the space station’s structural building block, during ground processing. The white flight cables around PMA-1 will assist in connecting the node to the U.S.-financed, Russian-built Functional Cargo Block, a component that supplies early power and propulsion systems for the station. Node 1 with two adapters attached will be the first element of the station to be launched aboard the Space Shuttle Endeavour on STS-88 in July 1998

KSC-97PC1139

NASA Image and Video Library

1997-07-26

The first of two Pressurized Mating Adapters, or PMAs, for the International Space Station arrive in KSC’s Space Station Processing Facility in July. A PMA is a cone-shaped connector that will be attached to Node 1, the space station’s structural building block, during ground processing. The adapter will house space station computers and various electrical support equipment and eventually will serve as the passageway for astronauts between the node and the U.S-financed, Russian-built Functional Cargo Block. Node 1 with two adapters attached will be the first element of the station to be launched aboard the Space Shuttle Endeavour on STS-88 in July 1998

KSC-97PC1140

NASA Image and Video Library

1997-07-26

The first of two Pressurized Mating Adapters, or PMAs, for the International Space Station arrive in KSC’s Space Station Processing Facility in July. A PMA is a cone-shaped connector that will be attached to Node 1, the space station’s structural building block, during ground processing. The adapter will house space station computers and various electrical support equipment and eventually will serve as the passageway for astronauts between the node and the U.S-financed, Russian-built Functional Cargo Block. Node 1 with two adapters attached will be the first element of the station to be launched aboard the Space Shuttle Endeavour on STS-88 in July 1998

KSC-97PC1137

NASA Image and Video Library

1997-07-26

International Space Station (ISS) contractors erect access scaffolding around the Pressurized Mating Adapter-1 (PMA-1) for the ISS in KSC’s Space Station Processing Facility. A PMA is a cone-shaped connector that will be attached to Node 1, the space station’s structural building block, during ground processing. The white flight cables around PMA-1 will assist in connecting the node to the U.S.-financed, Russian-built Functional Cargo Block, a component that supplies early power and propulsion systems for the station. Node 1 with two adapters attached will be the first element of the station to be launched aboard the Space Shuttle Endeavour on STS-88 in July 1998

Equivalent modulus method for finite element simulation of the sound absorption of anechoic coating backed with orthogonally rib-stiffened plate

NASA Astrophysics Data System (ADS)

Jin, Zhongkun; Yin, Yao; Liu, Bilong

2016-03-01

The finite element method is often used to investigate the sound absorption of anechoic coating backed with orthogonally rib-stiffened plate. Since the anechoic coating contains cavities, the number of grid nodes of a periodic unit cell is usually large. An equivalent modulus method is proposed to reduce the large amount of nodes by calculating an equivalent homogeneous layer. Applications of this method in several models show that the method can well predict the sound absorption coefficient of such structure in a wide frequency range. Based on the simulation results, the sound absorption performance of such structure and the influences of different backings on the first absorption peak are also discussed.

Membrane triangles with corner drilling freedoms. I - The EFF element

NASA Technical Reports Server (NTRS)

Alvin, Ken; De La Fuente, Horacio M.; Haugen, Bjorn; Felippa, Carlos A.

1992-01-01

The formulation of 3-node 9-DOF membrane elements with normal-to-element-plane rotations (drilling freedoms) is examined in the context of parametrized variational principles. In particular, attention is given to the application of the extended free formulation (EFF) to the construction of a triangular membrane element with drilling freedoms that initially has complete quadratic polynomial expansions in each displacement component. The main advantage of the EFF over the free formulation triangle is that an explicit form is obtained for the higher-order stiffness.

Fission-Fusion Adaptivity in Finite Elements for Nonlinear Dynamics of Shells

DTIC Science & Technology

1988-11-30

where mesh refinement will prove useful. In fact, the deviation of a bilinear element from a smooth shell midsurface can be related to the angle between...comparisons with nonadaptive meshes. Conclusions and further discussions are given in Section 6. -5- 2. FINITE ELEMENT FORMULATION The shape of the midsurface ...8217 22 , and e3 is defined so that e, and e2 are tangent to the midsurface and rotate with the element; 2. for each node, a triad b i is defined so that

Sentinel node mapping in endometrial cancer following Hysteroscopic injection of tracers: A single center evaluation over 200 cases.

PubMed

Martinelli, Fabio; Ditto, Antonino; Signorelli, Mauro; Bogani, Giorgio; Chiappa, Valentina; Lorusso, Domenica; Scaffa, Cono; Recalcati, Dario; Perotto, Stefania; Haeusler, Edward; Raspagliesi, Francesco

2017-09-01

To analyze detection-rate(DR) and diagnostic-accuracy (A) of sentinel-nodes(SLNs) mapping following hysteroscopic-injection of tracer. To compare DR and A between tracers: ICG and Tc99m. Evaluation of endometrial-cancer patients who underwent SLNs mapping after hysteroscopic-peritumoral-injection of tracer±lymphadenectomy. Analysis of DR (overall-bilateral-aortic) and A in the entire cohort and comparison between tracers. 202 procedures were performed from January/2005 to February/2017. Mean age:60years (28-82); mean BMI: 26.8 kg/m 2 (15-47). In 133 cases (65.8%) hysterectomy and mapping procedure were performed laparoscopically. The overall-DR of the technique was 93.2% (179/192) (10 cases were excluded: 9 for technical-equipment failure; 1 for vagal reaction). Bilateral pelvic mapping was found in 59.7% of cases (107/179) and was more frequent in the ICG group (72.8% vs 53.3%; p: 0.012). In 50.8% of cases (91/179) SLNs were mapped both in pelvic and aortic nodes, and in 5 cases (2.8%) only in the aortic area. The mean number of detected SLNs was 3.7 (1-8). 22 patients (12.3%) had nodal involvement: 10-(45.5%)-macrometastases; 5-(22.7%)-micrometastases; 7-(31.8%)-ITCs. In 6 cases (27.3%) only aortic nodes were positive; in 5 cases (22.7%) both pelvic and aortic nodes and in 11 cases (50%) only pelvic nodes were involved. Three false-negative results were found, all in the Tc99m group. All had isolated aortic metastases with negative pelvic nodes. Overall-sensitivity was 86.4% (95%CI: 68.4-100) and overall-negative-predictive-value (NPV) was 96.4% (95%CI 86.7-100). No differences in terms of overall-DR, overall-sensitivity and overall-NPV were found between the two tracers. Hysteroscopic-injection of tracer for SLNs mapping in endometrial cancer is as accurate as cervical injection with a higher DR in the aortic area. ICG improves bilateral-DR. Further investigation is warranted on this topic. Copyright © 2017 Elsevier Inc. All rights reserved.

Utilization and Outcomes of Sentinel Lymph Node Biopsy for Vulvar Cancer.

PubMed

Cham, Stephanie; Chen, Ling; Burke, William M; Hou, June Y; Tergas, Ana I; Hu, Jim C; Ananth, Cande V; Neugut, Alfred I; Hershman, Dawn L; Wright, Jason D

2016-10-01

To examine the use and predictors of sentinel node biopsy in women with vulvar cancer. The Perspective database, an all-payer database that collects data from more than 500 hospitals, was used to perform a retrospective cohort study of women with vulvar cancer who underwent vulvectomy and lymph node assessment from 2006 to 2015. Multivariable models were used to determine factors associated with sentinel node biopsy. Length of stay and cost were compared between women who underwent sentinel node biopsy and lymphadenectomy. Among 2,273 women, sentinel node biopsy was utilized in 618 (27.2%) and 1,655 (72.8%) underwent inguinofemoral lymphadenectomy. Performance of sentinel node biopsy increased from 17.0% (95% confidence interval [CI] 12.0-22.0%) in 2006 to 39.1% (95% CI 27.1-51.0%) in 2015. In a multivariable model, women treated more recently were more likely to have undergone sentinel node biopsy, whereas women with more comorbidities and those treated at rural hospitals were less likely to have undergone the procedure. The median length of stay was shorter for those undergoing sentinel node biopsy (median 2 days, interquartile range 1-3) compared with women who underwent inguinofemoral lymphadenectomy (median 3 days, interquartile range 2-4). The cost of sentinel node biopsy was $7,599 (interquartile range $5,739-9,922) compared with $8,095 (interquartile range $5,917-11,281) for lymphadenectomy. The use of sentinel node biopsy for vulvar cancer has more than doubled since 2006. Sentinel lymph node biopsy is associated with a shorter hospital stay and decreased cost compared with inguinofemoral lymphadenectomy.

Improved Life Prediction of Turbine Engine Components Using a Finite Element Based Software Called Zencrack

DTIC Science & Technology

2003-09-01

application .................................................. 5-42 5.10 Different materials within crack-block...5-30 Figure 5-29 - Application of required user edge node sets... applications . Users have at their disposal all of the capabilities within these finite element programs and may, if desired, include any number of

Moving Finite Elements in 2-D.

DTIC Science & Technology

1982-06-07

that a small number of control parameters would allow a great deal of flexibility in the type of node mobility available in specific problems while...CLEO 󈨕), Washington, DC, June 10-12, 1981.) 5. R. J. Gelinas and S. K. Doss, "The Moving Finite Element Method: 1-D Transient Flow Aplications ," to

Pressure deformation of tires using differential stiffness for triangular solid-of-revolution elements

NASA Technical Reports Server (NTRS)

Chen, C. H. S.

1975-01-01

The derivation is presented of the differential stiffness for triangular solid of revolution elements. The derivation takes into account the element rigid body rotation only, the rotation being about the circumferential axis. Internal pressurization of a pneumatic tire is used to illustrate the application of this feature.

Method and apparatus for acoustic plate mode liquid-solid phase transition detection

DOEpatents

Blair, Dianna S.; Freye, Gregory C.; Hughes, Robert C.; Martin, Stephen J.; Ricco, Antonio J.

1993-01-01

A method and apparatus for sensing a liquid-solid phase transition event is provided which comprises an acoustic plate mode detecting element placed in contact with a liquid or solid material which generates a high-frequency acoustic wave that is attenuated to an extent based on the physical state of the material is contact with the detecting element. The attenuation caused by the material in contact with the acoustic plate mode detecting element is used to determine the physical state of the material being detected. The method and device are particularly suited for detecting conditions such as the icing and deicing of wings of an aircraft. In another aspect of the present invention, a method is provided wherein the adhesion of a solid material to the detecting element can be measured using the apparatus of the invention.

The Posterior Cervical Lymph Node in Toxoplasmosis

PubMed Central

Gray, George F.; Kimball, Anne C.; Kean, B. H.

1972-01-01

Posterior cervical node enlargement is characteristic of clinical toxoplasmosis in adults. Lymph node biopsies from 37 patients, who were tested for toxoplasmosis by serologic and isolation studies, were examined. A characteristic pattern of sinus histiocytosis was seen in 17 of 18 posterior cervical nodes and in only 1 of 4 lymph nodes from other sites from patients with toxoplasmosis. The characteristic pattern was not seen in posterior cervical nodes or in lymph nodes from other sites from patients with other diseases. Lymphoma obscured the characteristic changes of toxoplasmosis in the posterior cervical nodes and other nodes of 5 patients with these coexisting diseases. Organisms were seen in tissue sections in only 2 instances. T gondii was isolated from mice in 14 of 17 attempts using nodes from patients with toxoplasmosis, but from none of 8 attempts using nodes from patients with other diseases. ImagesFig 3Fig 4Fig 1Fig 2 PMID:4634739

C6, C7, and C8 perfluoroalkyl-substituted phosphinic acids.

PubMed

Singh, R P; Shreeve, J M

2000-04-17

Reaction of red phosphorus with RfI in a 1:2 molar ratio at 230 degrees C led to the formation of a mixture of (Rf)2PI and (Rf)PI2 (Rf = C6F13, C7F15, C8F17) in about a 70:30 ratio, respectively. These mixtures were separated by vacuum distillation. (Rf)2PI (Rf = C6F13, C7F15) are yellow liquids whereas (C8F17)2PI is a yellow solid. Oxidation of (Rf)2PI with excess NO2 led to (Rf)2P(O)OH (Rf = C6F13, C7F15, C8F17) in > 90% isolated yields after aqueous hydrolysis of the anhydride intermediates. These highly fluorinated phosphinic acids are white solids with sharp melting points and are highly soluble in methyl sulfoxide (DMSO) and 1,1,2-trichlorotrifluoroethane. However, solubility in chloroform and methylene dichloride is low. These perfluoroalkylphosphinic acids were characterized by IR, NMR (1H, 19F, and 31P), and mass spectra and elemental analysis.

Indocyanine Green Guided Pelvic Lymph Node Dissection: An Efficient Technique to Classify the Lymph Node Status of Patients with Prostate Cancer Who Underwent Radical Prostatectomy.

PubMed

Ramírez-Backhaus, Miguel; Mira Moreno, Alejandra; Gómez Ferrer, Alvaro; Calatrava Fons, Ana; Casanova, Juan; Solsona Narbón, Eduardo; Ortiz Rodríguez, Isabel María; Rubio Briones, José

2016-11-01

We evaluated the effectiveness of indocyanine green guided pelvic lymph node dissection for the optimal staging of prostate cancer and analyzed whether the technique could replace extended pelvic lymph node dissection. A solution of 25 mg indocyanine green in 5 ml sterile water was transperineally injected. Pelvic lymph node dissection was started with the indocyanine green stained nodes followed by extended pelvic lymph node dissection. Primary outcome measures were sensitivity, specificity, predictive value and likelihood ratio of a negative test of indocyanine green guided pelvic lymph node dissection. A total of 84 patients with a median age of 63.55 years and a median prostate specific antigen of 8.48 ng/ml were included in the study. Of these patients 60.7% had intermediate risk disease and 25% had high or very high risk disease. A median of 7 indocyanine green stained nodes per patient was detected (range 2 to 18) with a median of 22 nodes excised during extended pelvic lymph node dissection. Lymph node metastasis was identified in 25 patients, 23 of whom had disease properly classified by indocyanine green guided pelvic lymph node dissection. The most frequent location of indocyanine green stained nodes was the proximal internal iliac artery followed by the fossa of Marcille. The negative predictive value was 96.7% and the likelihood ratio of a negative test was 8%. Overall 1,856 nodes were removed and 603 were stained indocyanine green. Pathological examination revealed 82 metastatic nodes, of which 60% were indocyanine green stained. The negative predictive value was 97.4% but the likelihood ratio of a negative test was 58.5%. Indocyanine green guided pelvic lymph node dissection correctly staged 97% of cases. However, according to our data it cannot replace extended pelvic lymph node dissection. Nevertheless, its high negative predictive value could allow us to avoid extended pelvic lymph node dissection if we had an accurate intraoperative lymph fluorescent analysis. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Advanced solid elements for sheet metal forming simulation

NASA Astrophysics Data System (ADS)

Mataix, Vicente; Rossi, Riccardo; Oñate, Eugenio; Flores, Fernando G.

2016-08-01

The solid-shells are an attractive kind of element for the simulation of forming processes, due to the fact that any kind of generic 3D constitutive law can be employed without any additional hypothesis. The present work consists in the improvement of a triangular prism solid-shell originally developed by Flores[2, 3]. The solid-shell can be used in the analysis of thin/thick shell, undergoing large deformations. The element is formulated in total Lagrangian formulation, and employs the neighbour (adjacent) elements to perform a local patch to enrich the displacement field. In the original formulation a modified right Cauchy-Green deformation tensor (C) is obtained; in the present work a modified deformation gradient (F) is obtained, which allows to generalise the methodology and allows to employ the Pull-Back and Push-Forwards operations. The element is based in three modifications: (a) a classical assumed strain approach for transverse shear strains (b) an assumed strain approach for the in-plane components using information from neighbour elements and (c) an averaging of the volumetric strain over the element. The objective is to use this type of elements for the simulation of shells avoiding transverse shear locking, improving the membrane behaviour of the in-plane triangle and to handle quasi-incompressible materials or materials with isochoric plastic flow.

Finite Element Modeling of the Buckling Response of Sandwich Panels

NASA Technical Reports Server (NTRS)

Rose, Cheryl A.; Moore, David F.; Knight, Norman F., Jr.; Rankin, Charles C.

2002-01-01

A comparative study of different modeling approaches for predicting sandwich panel buckling response is described. The study considers sandwich panels with anisotropic face sheets and a very thick core. Results from conventional analytical solutions for sandwich panel overall buckling and face-sheet-wrinkling type modes are compared with solutions obtained using different finite element modeling approaches. Finite element solutions are obtained using layered shell element models, with and without transverse shear flexibility, layered shell/solid element models, with shell elements for the face sheets and solid elements for the core, and sandwich models using a recently developed specialty sandwich element. Convergence characteristics of the shell/solid and sandwich element modeling approaches with respect to in-plane and through-the-thickness discretization, are demonstrated. Results of the study indicate that the specialty sandwich element provides an accurate and effective modeling approach for predicting both overall and localized sandwich panel buckling response. Furthermore, results indicate that anisotropy of the face sheets, along with the ratio of principle elastic moduli, affect the buckling response and these effects may not be represented accurately by analytical solutions. Modeling recommendations are also provided.

Surgical Staging of Early Stage Endometrial Cancer: Comparison Between Laparotomy and Laparoscopy

PubMed Central

Api, Murat; Kayatas, Semra; Boza, Aysen Telce; Nazik, Hakan; Adiguzel, Cevdet; Guzin, Kadir; Eroglu, Mustafa

2013-01-01

Background The aim of the present study was to compare the laparotomy (LT) and laparoscopy (LS) in patients who undergone surgical staging for early stage endometrium cancer. Methods Retrospective data were collected and analyzed for amount of intraoperative bleeding, complication rates, total resected and laterality specific number of lymph nodes and duration of operation in patients operated with either LT or LS. Results Seventy-nine stage I endometrium cancer patients were found to be eligible for the trial purposes: 58 (73.4%) treated by LT and 21 (26.6%) treated by LS. The number of lymph nodes was similar in LT (8.9 ± 5.3) and LS (9.2 ± 4.8) (P = 0.8). In LT group, there was no difference in the number of lymph nodes between the right and left sides (10 ± 5.8 and 8.7 ± 4.8 respectively, P = 0.19); in LS group, the number of lymph nodes resected from the right side was higher than the left side (9.8 ± 5 and 7 ± 3.5 respectively, P = 0.039). The amount of intraoperative bleeding and hospitalization period were significantly higher in LT group. Seventy-nine patients had a median follow-up of 30 months. The two groups were similar for disease-free survival (P = 0.46, log rank test). Conclusions There was no significant difference between the two methods in terms of number of total resected lymph nodes. In early stage endometrial carcinoma, LS has provided adequate staging and similar survival rates with LT. PMID:29147363

Recent Performance Results of VPIC on Trinity

NASA Astrophysics Data System (ADS)

Nystrom, W. D.; Bergen, B.; Bird, R. F.; Bowers, K. J.; Daughton, W. S.; Guo, F.; Le, A.; Li, H.; Nam, H.; Pang, X.; Stark, D. J.; Rust, W. N., III; Yin, L.; Albright, B. J.

2017-10-01

Trinity is a new DOE compute resource now in production at Los Alamos National Laboratory. Trinity has several new and unique features including two compute partitions, one with dual socket Intel Haswell Xeon compute nodes and one with Intel Knights Landing (KNL) Xeon Phi compute nodes, use of on package high bandwidth memory (HBM) for KNL nodes, ability to configure KNL nodes with respect to HBM model and on die network topology in a variety of operational modes at run time, and use of solid state storage via burst buffer technology to reduce time required to perform I/O. An effort is in progress to optimize VPIC on Trinity by taking advantage of these new architectural features. Results of work will be presented on performance of VPIC on Haswell and KNL partitions for single node runs and runs at scale. Results include use of burst buffers at scale to optimize I/O, comparison of strategies for using MPI and threads, performance benefits using HBM and effectiveness of using intrinsics for vectorization. Work performed under auspices of U.S. Dept. of Energy by Los Alamos National Security, LLC Los Alamos National Laboratory under contract DE-AC52-06NA25396 and supported by LANL LDRD program.

Solid oxide fuel cells, and air electrode and electrical interconnection materials therefor

DOEpatents

Bates, J. Lambert

1992-01-01

In one aspect of the invention, an air electrode material for a solid oxide fuel cell comprises Y.sub.1-a Q.sub.a MnO.sub.3, where "Q" is selected from the group consisting of Ca and Sr or mixtures thereof and "a" is from 0.1 to 0.8. Preferably, "a" is from 0.4 to 0.7. In another aspect of the invention, an electrical interconnection material for a solid oxide fuel cell comprises Y.sub.1-b Ca.sub.b Cr.sub.1-c Al.sub.c O.sub.3, where "b" is from 0.1 to 0.6 and "c" is from 0 to 9.3. Preferably, "b" is from 0.3 to 0.5 and "c" is from 0.05 to 0.1. A composite solid oxide electrochemical fuel cell incorporating these materials comprises: a solid oxide air electrode and an adjacent solid oxide electrical interconnection which commonly include the cation Y, the air electrode comprising Y.sub.1-a Q.sub.a MnO.sub.3, where "Q" is selected from the group consisting of Ca and Sr or mixtures thereof and "a" is from 0.1 to 0.8, the electrical interconnection comprising Y.sub.1-b Ca.sub.b Cr.sub.1-c Al.sub.c O.sub.3, where "b" is from 0.1 to 0.6 and "c" is from 0.0 to 0.3; a yttrium stabilized solid electrolyte comprising (1-d)ZrO.sub.2 -(d)Y.sub.2 O.sub.3 where "d" is from 0.06 to 0.5; and a solid fuel electrode comprising X-ZrO.sub.2, where "X" is an elemental metal.

Solid oxide fuel cells, and air electrode and electrical interconnection materials therefor

DOEpatents

Bates, J.L.

1992-09-01

In one aspect of the invention, an air electrode material for a solid oxide fuel cell comprises Y[sub 1[minus]a]Q[sub a]MnO[sub 3], where Q is selected from the group consisting of Ca and Sr or mixtures thereof and a' is from 0.1 to 0.8. Preferably, a' is from 0.4 to 0.7. In another aspect of the invention, an electrical interconnection material for a solid oxide fuel cell comprises Y[sub 1[minus]b]Ca[sub b]Cr[sub 1[minus]c]Al[sub c]O[sub 3], where b' is from 0.1 to 0.6 and c' is from 0 to 9.3. Preferably, b' is from 0.3 to 0.5 and c' is from 0.05 to 0.1. A composite solid oxide electrochemical fuel cell incorporating these materials comprises: a solid oxide air electrode and an adjacent solid oxide electrical interconnection which commonly include the cation Y, the air electrode comprising Y[sub 1[minus]a]Q[sub a]MnO[sub 3], where Q is selected from the group consisting of Ca and Sr or mixtures thereof and a' is from 0.1 to 0.8, the electrical interconnection comprising Y[sub 1[minus]b]Ca[sub b]Cr[sub 1[minus]c]Al[sub c]O[sub 3], where b' is from 0.1 to 0.6 and c' is from 0.0 to 0.3; a yttrium stabilized solid electrolyte comprising (1[minus]d)ZrO[sub 2]-(d)Y[sub 2]O[sub 3] where d' is from 0.06 to 0.5; and a solid fuel electrode comprising X-ZrO[sub 2], where X' is an elemental metal. 5 figs.

Computation of wind tunnel model deflections. [for transport type solid wing

NASA Technical Reports Server (NTRS)

Mehrotra, S. C.; Gloss, B. B.

1981-01-01

The experimental deflections for a transport type solid wing model were measured for several single point load conditions. These deflections were compared with those obtained by structural modeling of the wing by using plate and solid elements of Structural Performance Analysis and Redesign (SPAR) program. The solid element representation of the wing showed better agreement with the experimental deflections than the plate representation. The difference between the measured and calculated deflections is about 5 percent.

Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits

NASA Astrophysics Data System (ADS)

Yu, Leo; Natarajan, Chandra M.; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S.; Tanner, Michael G.; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H.; Fejer, Martin M.; Yamamoto, Yoshihisa

2015-11-01

Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances.

Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits.

PubMed

Yu, Leo; Natarajan, Chandra M; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S; Tanner, Michael G; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H; Fejer, Martin M; Yamamoto, Yoshihisa

2015-11-24

Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances.

International Space Station USOS Waste and Hygiene Compartment Development

NASA Technical Reports Server (NTRS)

Link, Dwight E., Jr.; Broyan, James Lee, Jr.; Gelmis, Karen; Philistine, Cynthia; Balistreri, Steven

2007-01-01

The International Space Station (ISS) currently provides human waste collection and hygiene facilities in the Russian Segment Service Module (SM) which supports a three person crew. Additional hardware is planned for the United States Operational Segment (USOS) to support expansion of the crew to six person capability. The additional hardware will be integrated in an ISS standard equipment rack structure that was planned to be installed in the Node 3 element; however, the ISS Program Office recently directed implementation of the rack, or Waste and Hygiene Compartment (WHC), into the U.S. Laboratory element to provide early operational capability. In this configuration, preserved urine from the WHC waste collection system can be processed by the Urine Processor Assembly (UPA) in either the U.S. Lab or Node 3 to recover water for crew consumption or oxygen production. The human waste collection hardware is derived from the Service Module system and is provided by RSC-Energia. This paper describes the concepts, design, and integration of the WHC waste collection hardware into the USOS including integration with U.S. Lab and Node 3 systems.

Polarization splitter based on interference effects in all-solid photonic crystal fibers.

PubMed

Mao, Dong; Guan, Chunying; Yuan, Libo

2010-07-01

We propose a novel kind of polarization splitter in all-solid photonic crystal fibers based on the mode interference effects. Both the full-vector finite-element method and the semi-vector three-dimensional beam propagation method are employed to design and analyze the characteristics of the splitter. Numerical simulations show that x-polarized and y-polarized modes are split entirely along with 6.8 mm long propagation. An extinction ratio of more than 20 dB and a crosstalk of less than -20 dB are obtained within the wavelength range of 1.541-1.556 microm. The extinction ratio and the crosstalk at 1.55 microm are 28.9 and -29.0 dB for x polarization, while the extinction ratio and the crosstalk at 1.55 microm are 29.9 and -29.8 dB for y polarization, respectively.

Compendium of Abstracts and Viewgraphs. International Workshop on Composite Materials and Structures for Rotorcraft (2nd) Held Rensselaer Polytechnic Institute, Troy, New York on 14-15 September 1989

DTIC Science & Technology

1989-11-30

The design of Composite Rotor Blades requires the analysis of tridimen- sional stress states including interlaminar stresses. Despite the powerfulness ...1500 grid points (-7000 DOF’s) * 350 8- noded shell elements ANALYTICAL SOLUTION General Differential Equation D22W1i + Elltf =otf - w y , W(x) L...STRAIN a (s) s = s22 K2 (1P) = (K12)2 / 11K22 GRiEF SPAR E+20,-70,+20,-70,-70,+201 NACA 0012 2.60 5 FE 802 6 S03 2 801 0o1 20 30 40 RADIAL STATION . IN

Solid/FEM integration at SNLA

NASA Technical Reports Server (NTRS)

Chavez, Patrick F.

1987-01-01

The effort at Sandia National Labs. on the methodologies and techniques being used to generate strict hexahedral finite element meshes from a solid model is described. The functionality of the modeler is used to decompose the solid into a set of nonintersecting meshable finite element primitives. The description of the decomposition is exported, via a Boundary Representative format, to the meshing program which uses the information for complete finite element model specification. Particular features of the program are discussed in some detail along with future plans for development which includes automation of the decomposition using artificial intelligence techniques.

Improved knowledge diffusion model based on the collaboration hypernetwork

NASA Astrophysics Data System (ADS)

Wang, Jiang-Pan; Guo, Qiang; Yang, Guang-Yong; Liu, Jian-Guo

2015-06-01

The process for absorbing knowledge becomes an essential element for innovation in firms and in adapting to changes in the competitive environment. In this paper, we present an improved knowledge diffusion hypernetwork (IKDH) model based on the idea that knowledge will spread from the target node to all its neighbors in terms of the hyperedge and knowledge stock. We apply the average knowledge stock V(t) , the variable σ2(t) , and the variance coefficient c(t) to evaluate the performance of knowledge diffusion. By analyzing different knowledge diffusion ways, selection ways of the highly knowledgeable nodes, hypernetwork sizes and hypernetwork structures for the performance of knowledge diffusion, results show that the diffusion speed of IKDH model is 3.64 times faster than that of traditional knowledge diffusion (TKDH) model. Besides, it is three times faster to diffuse knowledge by randomly selecting "expert" nodes than that by selecting large-hyperdegree nodes as "expert" nodes. Furthermore, either the closer network structure or smaller network size results in the faster knowledge diffusion.

A weak Galerkin least-squares finite element method for div-curl systems

NASA Astrophysics Data System (ADS)

Li, Jichun; Ye, Xiu; Zhang, Shangyou

2018-06-01

In this paper, we introduce a weak Galerkin least-squares method for solving div-curl problem. This finite element method leads to a symmetric positive definite system and has the flexibility to work with general meshes such as hybrid mesh, polytopal mesh and mesh with hanging nodes. Error estimates of the finite element solution are derived. The numerical examples demonstrate the robustness and flexibility of the proposed method.

Rationale of lymph node dissection for breast cancer--from the viewpoint of analysis of axillary lymphatic flow using activated carbon particle CH40.

PubMed

Sawai, K; Hagiwara, A; Shimotsuma, M; Sakakibara, T; Imanishi, T; Takemoto, Y; Takahashi, T

1996-03-01

In order to rationalize lymph node dissection for breast cancer, we reviewed regional lymphatic flow from the mesial and outer half of the breast using intra-tumoral injection of activated carbon particles (CH40). Seventy patients with breast cancer were included in this study. Cancers were located in the mesial half of the breast in 25 cases and in its outer half in 41 cases. Since regional lymph nodes were blackened by CH40, lymph node dissection was performed easily and small lymph nodes could be readily examined. The average number of resected nodes in each case was 29.4. When CH40 was injected into the mesial half of the breast, the rates of blackened nodes (number of macroscopically blackened lymph nodes/number of total removed lymph nodes) in the stations were 46.6% (No. 1a), 41.4% (No. 1b), 62.1% (No. 1c), 61.8% (No. 2), 69.2.% (No. 2h), and 65.6% (No. 3). When CH40 was injected into outer half of the breast, those were 62.0% (No. 1a), 64.3% (No. 1b), 68.7% (No. 1c), 75.3% (No. 2), and 67.8% (No. 2h). Regardless of tumor location, the rates of blackened nodes were high in each station. In conclusion, regardless of tumor location it is impossible to determine the level of axillary dissection for breast cancer. It should be all or nothing.

BOPACE 3-D (the Boeing Plastic Analysis Capability for 3-dimensional Solids Using Isoparametric Finite Elements)

NASA Technical Reports Server (NTRS)

Vos, R. G.; Straayer, J. W.

1975-01-01

The BOPACE 3-D is a finite element computer program, which provides a general family of three-dimensional isoparametric solid elements, and includes a new algorithm for improving the efficiency of the elastic-plastic-creep solution procedure. Theoretical, user, and programmer oriented sections are presented to describe the program.

Application of carbon nanoparticles in laparoscopic sentinel lymph node detection in patients with early-stage cervical cancer.

PubMed

Lu, Yan; Wei, Jin-Ying; Yao, De-Sheng; Pan, Zhong-Mian; Yao, Yao

2017-01-01

To investigate the value of carbon nanoparticles in identifying sentinel lymph nodes in early-stage cervical cancer. From January 2014 to January 2016, 40 patients with cervical cancer stage IA2-IIA, based on the International Federation of Gynecology and Obstetrics (FIGO) 2009 criteria, were included in this study. The normal cervix around the tumor was injected with a total of 1 mL of carbon nanoparticles (CNP)at 3 and 9 o'clock. All patients then underwent laparoscopic pelvic lymph node dissection and radical hysterectomy. The black-dyed sentinel lymph nodes were removed for routine pathological examination and immunohistochemical staining. Among the 40 patients, 38 patients had at least one sentinel lymph node (SLN). The detection rate was 95% (38/40). One hundred seventy-three SLNs were detected with an average of 3.9 SLNs per side. 25 positive lymph nodes, which included 21 positive SLNs, were detected in 8 (20%) patients. Sentinel lymph nodes were localized in the obturator (47.97%), internal lilac (13.87%), external lilac (26.59%), parametrial (1.16%), and common iliac (8.67%) regions. The sensitivity of the SLN detection was 100% (5/5), the accuracy was 97.37% (37/38), and the negative predictive value was 100. 0% and the false negative rate was 0%. Sentinel lymph nodes can be used to accurately predict the pathological state of pelvic lymph nodes in early cervical cancer. The detection rates and accuracy of sentinel lymph node were high. Carbon nanoparticles can be used to trace the sentinel lymph node in early cervical cancer.

Finite element analysis of the effect of a non-planar solid-liquid interface on the lateral solute segregation during unidirectional solidification

NASA Technical Reports Server (NTRS)

Carlson, F. M.; Chin, L.-Y.; Fripp, A. L.; Crouch, R. K.

1982-01-01

The effect of solid-liquid interface shape on lateral solute segregation during steady-state unidirectional solidification of a binary mixture is calculated under the assumption of no convection in the liquid. A finite element technique is employed to compute the concentration field in the liquid and the lateral segregation in the solid with a curved boundary between the liquid and solid phases. The computational model is constructed assuming knowledge of the solid-liquid interface shape; no attempt is made to relate this shape to the thermal field. The influence of interface curvature on the lateral compositional variation is investigated over a range of system parameters including diffusivity, growth speed, distribution coefficient, and geometric factors of the system. In the limiting case of a slightly nonplanar interface, numerical results from the finite element technique are in good agreement with the analytical solutions of Coriell and Sekerka obtained by using linear theory. For the general case of highly non-planar interface shapes, the linear theory fails and the concentration field in the liquid as well as the lateral solute segregation in the solid can be calculated by using the finite element method.

Oxygen concentration sensor for an internal combustion engine

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

Nakajima, T.; Okada, Y.; Mieno, T.

1988-09-29

This patent describes an oxygen concentration sensor, comprising: an oxygen ion conductive solid electrolyte member forming a gas diffusion restricted region into which a measuring gas is introduced; a pair of electrodes sandwiching the solid electrolyte member; pump current supply means applying a pump voltage to the pair of electrodes through a current detection element to generate a pump current; and a heater element connected to the solid electrolyte member for heating the solid electrolyte member for heating the solid electrolyte member when a heater current is supplied from a heater current source; wherein the oxygen concentration sensor detects anmore » oxygen concentration in the measuring gas in terms of a current value of the pump current supplied through the current detection element and controls oxygen concentration in the gas diffusion restricted region by conducting oxygen ions through the solid electrolyte member in accordance to the flow of the pump current; and wherein the current detection element is connected to the electrode of the pair of electrodes facing the gas diffusion restricted region for insuring that the current value is representative of the pump current and possible leakage current from the heater current.« less

DISN Forecast to Industry

DTIC Science & Technology

2008-08-08

Ms. Cindy E. Moran Director for Network Services 8 August 2008 DISN Forecast to Industry Report Documentation Page Form ApprovedOMB No. 0704-0188...TITLE AND SUBTITLE DISN (Defense Information system Network ) Forecast to Industry 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...Prescribed by ANSI Std Z39-18 2 2 Integrated DISN Services by 2016: A Solid Goal Network Aware Applications Common Storage & Retrieval Shared Long

Synthesis, characterization, and tuning of the liquid crystal properties of ionic materials based on the cyclic polyoxothiometalate [{Mo4O4S4(H2O)3(OH)2}2(P8W48O184)](36-).

PubMed

Watfa, Nancy; Floquet, Sébastien; Terazzi, Emmanuel; Haouas, Mohamed; Salomon, William; Korenev, Vladimir S; Taulelle, Francis; Guénée, Laure; Hijazi, Akram; Naoufal, Daoud; Piguet, Claude; Cadot, Emmanuel

2015-02-14

A series of compounds resulting from the ionic association of a nanoscopic inorganic cluster of formula [K2NaxLiy{Mo4O4S4(OH)2(H2O)3}2(HzP8W48O184)]((34-x-y-z)-), 1, with several organic cations such as dimethyldioctadecylammonium DODA(+), trimethylhexadecylammonium TMAC16(+), alkylmethylimidazoliums mimCn(+) (n = 12-20) and alkyl-dimethylimidazoliums dmimCn(+) (n = 12 and 16) was prepared and characterized in the solid state by FT-IR, EDX, Elemental analysis, TGA and solid state NMR. The solid state NMR experiments performed on (1)H, (13)C and (31)P nuclei evidenced the interactions between the cations and 1 as well as the organization of the alkyl chains of the cations within the solid. Polarized optical microscopy, DSC and SA-XRD experiments implicated mesomorphic phases for DODA(+) and mimCn(+) salts of 1. The crystallographic parameters were determined and demonstrated that the inter-lamellar spacing could be controlled upon changing the length of the alkyl chain, a very interesting result if we consider the huge size of the inorganic cluster 1 and the simple nature of the cations.

Minimizing EIT image artefacts from mesh variability in finite element models.

PubMed

Adler, Andy; Lionheart, William R B

2011-07-01

Electrical impedance tomography (EIT) solves an inverse problem to estimate the conductivity distribution within a body from electrical simulation and measurements at the body surface, where the inverse problem is based on a solution of Laplace's equation in the body. Most commonly, a finite element model (FEM) is used, largely because of its ability to describe irregular body shapes. In this paper, we show that simulated variations in the positions of internal nodes within a FEM can result in serious image artefacts in the reconstructed images. Such variations occur when designing FEM meshes to conform to conductivity targets, but the effects may also be seen in other applications of absolute and difference EIT. We explore the hypothesis that these artefacts result from changes in the projection of the anisotropic conductivity tensor onto the FEM system matrix, which introduces anisotropic components into the simulated voltages, which cannot be reconstructed onto an isotropic image, and appear as artefacts. The magnitude of the anisotropic effect is analysed for a small regular FEM, and shown to be proportional to the relative node movement as a fraction of element size. In order to address this problem, we show that it is possible to incorporate a FEM node movement component into the formulation of the inverse problem. These results suggest that it is important to consider artefacts due to FEM mesh geometry in EIT image reconstruction.

Rapid detection of metastatic melanoma in lymph nodes using proton magnetic resonance spectroscopy of fine needle aspiration biopsy specimens.

PubMed

Lean, Cynthia L; Bourne, Roger; Thompson, John F; Scolyer, Richard A; Stretch, Jonathan; Li, Ling-Xi Lawrence; Russell, Peter; Mountford, Carolyn

2003-06-01

Accurate staging of patients with primary cutaneous melanoma includes assessment of regional lymph nodes for the presence of micrometastatic disease. Sentinel lymph node biopsy is highly accurate but is an invasive surgical procedure with a 5-10% complication rate, and requires labour-intensive and expensive histological examination to identify disease. A rapid, accurate and cost-effective non-surgical technique able to detect micrometastatic deposits of melanoma in regional lymph nodes would be of great benefit. Fine needle aspiration biopsies and tissue specimens were obtained from lymph nodes from 18 patients undergoing node resection for metastatic melanoma and five patients undergoing radical retropubic prostatectomy. One-dimensional proton magnetic resonance spectroscopy was undertaken at 360 MHz (8.5 T). Lymph nodes were cut into 3 mm thick slices and embedded. Four sequential 5 microm tissue sections were cut from each block and stained, with haematoxylin and eosin, for S100 protein, for HMB45, and again with haematoxylin and eosin, respectively. Proton magnetic resonance spectroscopy distinguished between benign and malignant lymph node tissue (P < 0.001, separate t-test) and benign and malignant lymph node fine needle aspiration biopsy (P < 0.012) based on the ratio of the integrals of resonances from lipid/other metabolites (1.8-2.5 p.p.m. region) and 'choline' (3.1-3.3 p.p.m. region). In conclusion, one-dimensional proton magnetic resonance spectroscopy on a simple fine needle aspiration biopsy can distinguish lymph nodes containing metastatic melanoma from uninvolved nodes, providing a rapid, accurate and cost-effective non-surgical technique to assess regional lymph nodes in patients with melanoma.

Evaluation of ADINA. Part I. Theory and Programing Descriptions.

DTIC Science & Technology

1980-06-08

Problem," Numerical and Computer Methods in Structural Mechanics, S. J. Feaves, N. Pe-rone, J. Robinson and W.C. Schnobrich, eds., Academic Press, New...connectivity array N102 ’NDM*NlJME-ITW0 YL Element nodal coordinates N103 ---- NUME IELT Element number of nodes N104 NUME IPST Stress printing flag N105 NUME

Development of electrochemical super capacitors for EMA applications

NASA Technical Reports Server (NTRS)

Kosek, J. A.; Dunning, T.; Laconti, A. B.

1995-01-01

In a NASA SBIR Phase I program (Contract No. NAS8-40119), Giner, Inc. evaluated the feasibility of fabricating an all-solid-ionomer multicell electrochemical capacitor having a unit cell capacitance greater than 2 F/sq cm and a repeating element thickness of 6 mils. This capacitor can possibly be used by NASA as a high-rate energy source for electromechanical actuator (EMA) activation for advanced space missions. The high unit cell capacitance and low repeating element thickness will allow for the fabrication of a low-volume, low-weight device, favorable characteristics for space applications. These same characteristics also make the capacitor attractive for terrestrial applications, such as load-leveling batteries or fuel cells in electric vehicle applications. Although the projected energy densities for electrochemical capacitors are about two orders of magnitude lower than that of batteries, the high-power-density characteristics of these devices render them as potentially viable candidates for meeting pulse or peak electrical power requirements for some anticipated aerospace mission scenarios, especially those with discharge times on the millisecond to second time scale. On a volumetric or gravimetric basis, the advantages of utilizing electrochemical capacitors rather than batteries for meeting the peak power demands associated with a specific mission scenario will largely depend upon the total and pulse durations of the power peaks. The effect of preparation conditions on RuO(x), the active component in an all-solid-ionomer electrochemical capacitor, was evaluated during this program. Methods were identified to prepare RuO(x) having a surface areagreater than 180 sq m/g, and a capacitance of greater than 2 F/sq cm. Further efforts to reproducibly obtain these high-surface-area materials in scaled-up batches will be evaluated in Phase 2. During this Phase 1 program we identified a superior Nafion 105 membrane, having a film thickness of 5 mils, that showed excellent performance in our all-solid-ionomer capacitors and resulted in electrochemical capacitors with a repeating element thickness of 8 mils. We are currently working with membrane manufacturers to obtain a high performance membrane in less than 3 mil thickness to obtain a repeating element thickness of 6 mils or less. A 10-cell all-solid ionomer capacitor stack, with each cell having a 222 sq cm active area, was fabricated and evaluated as part of the Phase 1 program. Further Scale-up of a high-energy-density stack is plannedin Phase 2.

An efficient finite element with layerwise mechanics for smart piezoelectric composite and sandwich shallow shells

NASA Astrophysics Data System (ADS)

Yasin, M. Yaqoob; Kapuria, S.

2014-01-01

In this work, we present a new efficient four-node finite element for shallow multilayered piezoelectric shells, considering layerwise mechanics and electromechanical coupling. The laminate mechanics is based on the zigzag theory that has only seven kinematic degrees of freedom per node. The normal deformation of the piezoelectric layers under the electric field is accounted for without introducing any additional deflection variables. A consistent quadratic variation of the electric potential across the piezoelectric layers with the provision of satisfying the equipotential condition of electroded surfaces is adopted. The performance of the new element is demonstrated for the static response under mechanical and electric potential loads, and for free vibration response of smart shells under different boundary conditions. The predictions are found to be very close to the three dimensional piezoelasticity solutions for hybrid shells made of not only single-material composite substrates, but also sandwich substrates with a soft core for which the equivalent single layer (ESL) theories perform very badly.

NESTOR: A Computer-Based Medical Diagnostic Aid That Integrates Causal and Probabilistic Knowledge.

DTIC Science & Technology

1984-11-01

indiidual conditional probabilities between one cause node and its effect node, but less common to know a joint conditional probability between a...PERFOAMING ORG. REPORT NUMBER * 7. AUTI4ORs) O Gregory F. Cooper 1 CONTRACT OR GRANT NUMBERIa) ONR N00014-81-K-0004 g PERFORMING ORGANIZATION NAME AND...ADDRESS 10. PROGRAM ELEMENT, PROJECT. TASK Department of Computer Science AREA & WORK UNIT NUMBERS Stanford University Stanford, CA 94305 USA 12. REPORT

The pattern of lymphatic metastasis of breast cancer and its influence on the delineation of radiation fields

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

Yu Jinming; Li Gong; Li Jianbin

2005-03-01

Purpose: The delineation of radiation fields should cover the clinical target volume (CTV) and minimally irradiate the surrounding normal tissues and organs. This study was designed to explore the pattern of lymphatic metastasis of breast cancer and indications for radiotherapy after radical or modified radical mastectomy and to discuss the rational delineation of radiation fields. Methods and materials: Between September 1980 and December 2003, 78 breast cancer patients receiving extended radical mastectomy in the Margottini model and 61 cases with complete data were analyzed to investigate the internal mammary lymphatic metastatic status. Between March 1988 and December 1988, 46 patientsmore » with clinical negative supraclavicular nodes received radical mastectomy plus supraclavicular lymph node dissection. The supraclavicular lymph nodes and axillary lymph nodes were labeled as S and levels I, II, or III, respectively, and examined pathologically. Between January 1996 and April 1999, 412 patients who had radical or modified radical mastectomy underwent the pathologic examination of axillary or levels I, II, or III nodes. Results: The incidence of internal mammary lymph node metastasis was 24.6%. It was 36.7% for the patients with positive axillary lymph nodes and 12.9% for the patients with negative axillary lymph nodes. All the metastatic internal mammary lymph nodes were located at the first, second, and third intercostal spaces. Skipping metastasis of the supraclavicular and axillary lymph nodes was observed in 3.8% and 8.1% of patients, respectively. Conclusions: According to our data, we suggest that the radiation field for internal mammary lymph nodes should exclude the fourth and fifth intercostal spaces, which may help to reduce the radiation damage to heart. It is unnecessary to irradiate the supraclavicular lymph nodes for the patients with negative axillary level III nodes, even with positive level I and level II nodes.« less

TACT1- TRANSIENT THERMAL ANALYSIS OF A COOLED TURBINE BLADE OR VANE EQUIPPED WITH A COOLANT INSERT

NASA Technical Reports Server (NTRS)

Gaugler, R. E.

1994-01-01

As turbine-engine core operating conditions become more severe, designers must develop more effective means of cooling blades and vanes. In order to design reliable, cooled turbine blades, advanced transient thermal calculation techniques are required. The TACT1 computer program was developed to perform transient and steady-state heat-transfer and coolant-flow analyses for cooled blades, given the outside hot-gas boundary condition, the coolant inlet conditions, the geometry of the blade shell, and the cooling configuration. TACT1 can analyze turbine blades, or vanes, equipped with a central coolant-plenum insert from which coolant-air impinges on the inner surface of the blade shell. Coolant-side heat-transfer coefficients are calculated with the heat transfer mode at each station being user specified as either impingement with crossflow, forced convection channel flow, or forced convection over pin fins. A limited capability to handle film cooling is also available in the program. The TACT1 program solves for the blade temperature distribution using a transient energy equation for each node. The nodal energy balances are linearized, one-dimensional, heat-conduction equations which are applied at the wall-outer-surface node, at the junction of the cladding and the metal node, and at the wall-inner-surface node. At the mid-metal node a linear, three-dimensional, heat-conduction equation is used. Similarly, the coolant pressure distribution is determined by solving the set of transfer momentum equations for the one-dimensional flow between adjacent fluid nodes. In the coolant channel, energy and momentum equations for one-dimensional compressible flow, including friction and heat transfer, are used for the elemental channel length between two coolant nodes. The TACT1 program first obtains a steady-state solution using iterative calculations to obtain convergence of stable temperatures, pressures, coolant-flow split, and overall coolant mass balance. Transient calculations are based on the steady-state solutions obtained. Input to the TACT1 program includes a geometrical description of the blade and insert, the nodal spacing to be used, and the boundary conditions describing the outside hot-gas and the coolant-inlet conditions. The program output includes the value of nodal temperatures and pressures at each iteration. The final solution output includes the temperature at each coolant node, and the coolant flow rates and Reynolds numbers. This program is written in FORTRAN IV for batch execution and has been implemented on an IBM 360 computer with a central memory requirement of approximately 480K of 8 bit bytes. The TACT1 program was developed in 1978.

Nonlinear solid finite element analysis of mitral valves with heterogeneous leaflet layers

NASA Astrophysics Data System (ADS)

Prot, V.; Skallerud, B.

2009-02-01

An incompressible transversely isotropic hyperelastic material for solid finite element analysis of a porcine mitral valve response is described. The material model implementation is checked in single element tests and compared with a membrane implementation in an out-of-plane loading test to study how the layered structures modify the stress response for a simple geometry. Three different collagen layer arrangements are used in finite element analysis of the mitral valve. When the leaflets are arranged in two layers with the collagen on the ventricular side, the stress in the fibre direction through the thickness in the central part of the anterior leaflet is homogenized and the peak stress is reduced. A simulation using membrane elements is also carried out for comparison with the solid finite element results. Compared to echocardiographic measurements, the finite element models bulge too much in the left atrium. This may be due to evidence of active muscle fibres in some parts of the anterior leaflet, whereas our constitutive modelling is based on passive material.

A seismic analysis for masonry constructions: The different schematization methods of masonry walls

NASA Astrophysics Data System (ADS)

Olivito, Renato. S.; Codispoti, Rosamaria; Scuro, Carmelo

2017-11-01

Seismic analysis of masonry structures is usually analyzed through the use of structural calculation software based on equivalent frames method or to macro-elements method. In these approaches, the masonry walls are divided into vertical elements, masonry walls, and horizontal elements, so-called spandrel elements, interconnected by rigid nodes. The aim of this work is to make a critical comparison between different schematization methods of masonry wall underlining the structural importance of the spandrel elements. In order to implement the methods, two different structural calculation software were used and an existing masonry building has been examined.

Simulating the Effect of Space Vehicle Environments on Directional Solidification of a Binary Alloy

NASA Technical Reports Server (NTRS)

Westra, D. G.; Heinrich, J. C.; Poirier, D. R.

2003-01-01

Space microgravity missions are designed to provide a microgravity environment for scientific experiments, but these missions cannot provide a perfect environment, due to vibrations caused by crew activity, on-board experiments, support systems (pumps, fans, etc.), periodic orbital maneuvers, and water dumps. Therefore, it is necessary to predict the impact of these vibrations on space experiments, prior to performing them. Simulations were conducted to study the effect of the vibrations on the directional solidification of a dendritic alloy. Finite element ca!cu!attie?ls were dme with a simd2titcr based on a continuum model of dendritic solidification, using the Fractional Step Method (FSM). The FSM splits the solution of the momentum equation into two steps: the viscous intermediate step, which does not enforce continuity; and the inviscid projection step, which calculates the pressure and enforces continuity. The FSM provides significant computational benefits for predicting flows in a directionally solidified alloy, compared to other methods presently employed, because of the efficiency gains in the uncoupled solution of velocity and pressure. finite differences, arises when the interdendritic liquid reaches the eutectic temperature and concentration. When a node reaches eutectic temperature, it is assumed that the solidification of the eutectic liquid continues at constant temperature until all the eutectic is solidified. With this approach, solidification is not achieved continuously across an element; rather, the element is not considered solidified until the eutectic isotherm overtakes the top nodes. For microgravity simulations, where the convection is driven by shrinkage, it introduces large variations in the fluid velocity. When the eutectic isotherm reaches a node, all the eutectic must be solidified in a short period, causing an abrupt increase in velocity. To overcome this difficulty, we employed a scheme to numerically predict a more accurate value for the rate of change of fraction of liquid as the liquid in an element solidifies. The new method enables us to contrast results of simulations in which the alloy is subjected to no gravity or a steady-state acceleration versus simulations when the alloy is subjected to vibration disturbances; therefore, the effect of vibration disturbances can be assessed more accurately. To assess the impact of these vibration-perturbations, transient accelerometer data from a space shuttle mission are used as inputs for the simulation model. These on-orbit acceleration data were obtained from the Microgravity Science Division at Glenn Research Center (GRC- MSD) and are applied to the buoyancy term of the momentum equation in a simulation of a Pb-5.8 wt. % Sb alloy that solidifies in a thermal gradient of 4000 K/m and a translation velocity of 3 p d s . Figure 2 shows the vertical velocity of a node that begins in the all-liquid region and subsequently solidifies; the vibrations are applied at 5000 seconds in this simulation. An important difficulty, common to all solidification models based on finite elements or 2 The magnitudes of the velocity oscillations that are vibration-induced are very small and acceptable. The biggest concern is whether the concentration of the liquid near the dendrite tips is distorted because of the vibration-induced perturbations. Results for this case show no concentration oscillations present in the all-liquid region.

System for conversion between the boundary representation model and a constructive solid geometry model of an object

DOEpatents

Christensen, Noel C.; Emery, James D.; Smith, Maurice L.

1988-04-05

A system converts from the boundary representation of an object to the constructive solid geometry representation thereof. The system converts the boundary representation of the object into elemental atomic geometrical units or I-bodies which are in the shape of stock primitives or regularized intersections of stock primitives. These elemental atomic geometrical units are then represented in symbolic form. The symbolic representations of the elemental atomic geometrical units are then assembled heuristically to form a constructive solid geometry representation of the object usable for manufacturing thereof. Artificial intelligence is used to determine the best constructive solid geometry representation from the boundary representation of the object. Heuristic criteria are adapted to the manufacturing environment for which the device is to be utilized. The surface finish, tolerance, and other information associated with each surface of the boundary representation of the object are mapped onto the constructive solid geometry representation of the object to produce an enhanced solid geometry representation, particularly useful for computer-aided manufacture of the object.

Meshless methods in shape optimization of linear elastic and thermoelastic solids

NASA Astrophysics Data System (ADS)

Bobaru, Florin

This dissertation proposes a meshless approach to problems in shape optimization of elastic and thermoelastic solids. The Element-free Galerkin (EFG) method is used for this purpose. The ability of the EFG to avoid remeshing, that is normally done in a Finite Element approach to correct highly distorted meshes, is clearly demonstrated by several examples. The shape optimization example of a thermal cooling fin shows a dramatic improvement in the objective compared to a previous FEM analysis. More importantly, the new solution, displaying large shape changes contrasted to the initial design, was completely missed by the FEM analysis. The EFG formulation given here for shape optimization "uncovers" new solutions that are, apparently, unobtainable via a FEM approach. This is one of the main achievements of our work. The variational formulations for the analysis problem and for the sensitivity problems are obtained with a penalty method for imposing the displacement boundary conditions. The continuum formulation is general and this facilitates 2D and 3D with minor differences from one another. Also, transient thermoelastic problems can use the present development at each time step to solve shape optimization problems for time-dependent thermal problems. For the elasticity framework, displacement sensitivity is obtained in the EFG context. Excellent agreements with analytical solutions for some test problems are obtained. The shape optimization of a fillet is carried out in great detail, and results show significant improvement of the EFG solution over the FEM or the Boundary Element Method solutions. In our approach we avoid differentiating the complicated EFG shape functions, with respect to the shape design parameters, by using a particular discretization for sensitivity calculations. Displacement and temperature sensitivities are formulated for the shape optimization of a linear thermoelastic solid. Two important examples considered in this work, the optimization of a thermal fin and of a uniformly loaded thermoelastic beam, reveal new characteristics of the EFG method in shape optimization applications. Among other advantages of the EFG method over traditional FEM treatments of shape optimization problems, some of the most important ones are shown to be: elimination of post-processing for stress and strain recovery that directly gives more accurate results in critical positions (near the boundaries, for example) for shape optimization problems; nodes movement flexibility that permits new, better shapes (previously missed by an FEM analysis) to be discovered. Several new research directions that need further consideration are exposed.

Strain energy release rate analysis of the end-notched flexure specimen using the finite-element method

NASA Technical Reports Server (NTRS)

Salpekar, S. A.; Raju, I. S.; O'Brien, T. K.

1988-01-01

Two-dimensional finite-element analysis of the end-notched flexure specimen was performed using 8-node isoparametric, parabolic elements to evaluate compliance and mode II strain energy release rates, G sub II. The G sub II values were computed using two different techniques: the virtual crack-closure technique (VCCT) and the rate of change of compliance with crack length (compliance derivative method). The analysis was performed for various crack-length-to-semi-span (a/L) ratios ranging from 0.2 to 0.9. Three material systems representing a wide range of material properties were analyzed. The compliance and strain energy release rates of the specimen calculated with the present finite-element analysis agree very well with beam theory equations including transverse shear. The G sub II values calculated using the compliance derivative method compared extremely well with those calculated using the VCCT. The G sub II values obtained by the compliance derivative method using the top or bottom beam deflections agreed closely with each other. The strain energy release rates from a plane-stress analysis were higher than the plane-strain values by only a small percentage, indicating that either assumption may be used in the analysis. The G sub II values for one material system calculated from the finte-element analysis agreed with one solution in the literature and disagreed with the other solution in the literature.

Strain-energy-release rate analysis of the end-notched flexure specimen using the finite-element method

NASA Technical Reports Server (NTRS)

Salpekar, S. A.; Raju, I. S.; Obrien, T. K.

1987-01-01

Two-dimensional finite-element analysis of the end-notched flexure specimen was performed using 8-node isoparametric, parabolic elements to evaluate compliance and mode II strain energy release rates, G sub II. The G sub II values were computed using two different techniques: the virtural crack-closure technique (VCCT) and the rate of change of compliance with crack length (compliance derivative method). The analysis was performed for various crack-length-to-semi-span (a/L) ratios ranging from 0.2 to 0.9. Three material systems representing a wide range of material properties were analyzed. The compliance and strain energy release rates of the specimen calculated with the present finite-element analysis agree very well with beam theory equations including transverse shear. The G sub II values calculated using the compliance derivative method compared extremely well with those calculated using the VCCT. The G sub II values obtained by the compliance derivative method using the top or bottom beam deflections agreed closely with each other. The strain energy release rates from a plane-stress analysis were higher than the plane-strain values by only a small percentage, indicating that either assumption may be used in the analysis. The G sub II values for one material system calculated from the finite-element analysis agreed with one solution in the literature and disagreed with the other solution in the literature.

A simple finite element method for non-divergence form elliptic equation

DOE PAGES

Mu, Lin; Ye, Xiu

2017-03-01

Here, we develop a simple finite element method for solving second order elliptic equations in non-divergence form by combining least squares concept with discontinuous approximations. This simple method has a symmetric and positive definite system and can be easily analyzed and implemented. We could have also used general meshes with polytopal element and hanging node in the method. We prove that our finite element solution approaches to the true solution when the mesh size approaches to zero. Numerical examples are tested that demonstrate the robustness and flexibility of the method.

A simple finite element method for non-divergence form elliptic equation

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

Mu, Lin; Ye, Xiu

Here, we develop a simple finite element method for solving second order elliptic equations in non-divergence form by combining least squares concept with discontinuous approximations. This simple method has a symmetric and positive definite system and can be easily analyzed and implemented. We could have also used general meshes with polytopal element and hanging node in the method. We prove that our finite element solution approaches to the true solution when the mesh size approaches to zero. Numerical examples are tested that demonstrate the robustness and flexibility of the method.

Users manual for AUTOMESH-2D: A program of automatic mesh generation for two-dimensional scattering analysis by the finite element method

NASA Technical Reports Server (NTRS)

Hua, Chongyu; Volakis, John L.

1990-01-01

AUTOMESH-2D is a computer program specifically designed as a preprocessor for the scattering analysis of two dimensional bodies by the finite element method. This program was developed due to a need for reproducing the effort required to define and check the geometry data, element topology, and material properties. There are six modules in the program: (1) Parameter Specification; (2) Data Input; (3) Node Generation; (4) Element Generation; (5) Mesh Smoothing; and (5) Data File Generation.

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

Kuprat, A.P.; Glasser, A.H.

The authors discuss unstructured grids for application to transport in the tokamak edge SOL. They have developed a new metric with which to judge element elongation and resolution requirements. Using this method, the authors apply a standard moving finite element technique to advance the SOL equations while inserting/deleting dynamically nodes that violate an elongation criterion. In a tokamak plasma, this method achieves a more uniform accuracy, and results in highly stretched triangular finite elements, except near separatrix X-point where transport is more isotropic.

A combined application of boundary-element and Runge-Kutta methods in three-dimensional elasticity and poroelasticity

NASA Astrophysics Data System (ADS)

Igumnov, Leonid; Ipatov, Aleksandr; Belov, Aleksandr; Petrov, Andrey

2015-09-01

The report presents the development of the time-boundary element methodology and a description of the related software based on a stepped method of numerical inversion of the integral Laplace transform in combination with a family of Runge-Kutta methods for analyzing 3-D mixed initial boundary-value problems of the dynamics of inhomogeneous elastic and poro-elastic bodies. The results of the numerical investigation are presented. The investigation methodology is based on direct-approach boundary integral equations of 3-D isotropic linear theories of elasticity and poroelasticity in Laplace transforms. Poroelastic media are described using Biot models with four and five base functions. With the help of the boundary-element method, solutions in time are obtained, using the stepped method of numerically inverting Laplace transform on the nodes of Runge-Kutta methods. The boundary-element method is used in combination with the collocation method, local element-by-element approximation based on the matched interpolation model. The results of analyzing wave problems of the effect of a non-stationary force on elastic and poroelastic finite bodies, a poroelastic half-space (also with a fictitious boundary) and a layered half-space weakened by a cavity, and a half-space with a trench are presented. Excitation of a slow wave in a poroelastic medium is studied, using the stepped BEM-scheme on the nodes of Runge-Kutta methods.

Ultralightweight Space Deployable Primary Reflector Demonstrator

NASA Technical Reports Server (NTRS)

Montgomery, Edward E., IV; Zeiders, Glenn W.; Smith, W. Scott (Technical Monitor)

2002-01-01

A concept has been developed and analyzed and several generational prototypes built for a gossamer-class deployable truss for a mirror or reflector with many smaller precisely-figured solid elements attached will, for at least the next several decades, minimize the mass of a large primary mirror assembly while still providing the high image quality essential for planet-finding and cosmological astronomical missions. Primary mirror segments are mounted in turn on ultralightweight thermally-formed plastic panels that hold clusters of mirror segments in rigid arrays whose tip/tilt and piston would be corrected over the scale of the plastic panels by the control segments. Prototype panels developed under this program are 45 cm wide and fabricated from commercially available Kaplan sheets. A three-strut octahedral tensegrity is the basis for the overall support structure. Each fundamental is composed of two such octahedrons, rotated oppositely about a common triangular face. Adjacent modules are joined at the nodes of the upper and lower triangles to form a deployable structure that could be made arbitrarily large. A seven-module dowel-and-wire prototype has been constructed. Deployment techniques based on the use of collapsing toggled struts with diagonal tensional elements allows an assembly of tensegrities to be fully collapsed and redeployed. The prototype designs will be described and results of a test program for measuring strength and deformation will be presented.

Cross-Disciplinary Analysis of Lymph Node Classification in Lung Cancer on CT Scanning.

PubMed

El-Sherief, Ahmed H; Lau, Charles T; Obuchowski, Nancy A; Mehta, Atul C; Rice, Thomas W; Blackstone, Eugene H

2017-04-01

Accurate and consistent regional lymph node classification is an important element in the staging and multidisciplinary management of lung cancer. Regional lymph node definition sets-lymph node maps-have been created to standardize regional lymph node classification. In 2009, the International Association for the Study of Lung Cancer (IASLC) introduced a lymph node map to supersede all preexisting lymph node maps. Our aim was to study if and how lung cancer specialists apply the IASLC lymph node map when classifying thoracic lymph nodes encountered on CT scans during lung cancer staging. From April 2013 through July 2013, invitations were distributed to all members of the Fleischner Society, Society of Thoracic Radiology, General Thoracic Surgical Club, and the American Association of Bronchology and Interventional Pulmonology to participate in an anonymous online image-based and text-based 20-question survey regarding lymph node classification for lung cancer staging on CT imaging. Three hundred thirty-seven people responded (approximately 25% participation). Respondents consisted of self-reported thoracic radiologists (n = 158), thoracic surgeons (n = 102), and pulmonologists who perform endobronchial ultrasonography (n = 77). Half of the respondents (50%; 95% CI, 44%-55%) reported using the IASLC lymph node map in daily practice, with no significant differences between subspecialties. A disparity was observed between the IASLC definition sets and their interpretation and application on CT scans, in particular for lymph nodes near the thoracic inlet, anterior to the trachea, anterior to the tracheal bifurcation, near the ligamentum arteriosum, between the bronchus intermedius and esophagus, in the internal mammary space, and adjacent to the heart. Use of older lymph node maps and inconsistencies in interpretation and application of definitions in the IASLC lymph node map may potentially lead to misclassification of stage and suboptimal management of lung cancer in some patients. Published by Elsevier Inc.

The sensitivity of biological finite element models to the resolution of surface geometry: a case study of crocodilian crania

PubMed Central

Evans, Alistair R.; McHenry, Colin R.

2015-01-01

The reliability of finite element analysis (FEA) in biomechanical investigations depends upon understanding the influence of model assumptions. In producing finite element models, surface mesh resolution is influenced by the resolution of input geometry, and influences the resolution of the ensuing solid mesh used for numerical analysis. Despite a large number of studies incorporating sensitivity studies of the effects of solid mesh resolution there has not yet been any investigation into the effect of surface mesh resolution upon results in a comparative context. Here we use a dataset of crocodile crania to examine the effects of surface resolution on FEA results in a comparative context. Seven high-resolution surface meshes were each down-sampled to varying degrees while keeping the resulting number of solid elements constant. These models were then subjected to bite and shake load cases using finite element analysis. The results show that incremental decreases in surface resolution can result in fluctuations in strain magnitudes, but that it is possible to obtain stable results using lower resolution surface in a comparative FEA study. As surface mesh resolution links input geometry with the resulting solid mesh, the implication of these results is that low resolution input geometry and solid meshes may provide valid results in a comparative context. PMID:26056620

Multifrequency Ultra-High Resolution Miniature Scanning Microscope Using Microchannel And Solid-State Sensor Technologies And Method For Scanning Samples

NASA Technical Reports Server (NTRS)

Wang, Yu (Inventor)

2006-01-01

A miniature, ultra-high resolution, and color scanning microscope using microchannel and solid-state technology that does not require focus adjustment. One embodiment includes a source of collimated radiant energy for illuminating a sample, a plurality of narrow angle filters comprising a microchannel structure to permit the passage of only unscattered radiant energy through the microchannels with some portion of the radiant energy entering the microchannels from the sample, a solid-state sensor array attached to the microchannel structure, the microchannels being aligned with an element of the solid-state sensor array, that portion of the radiant energy entering the microchannels parallel to the microchannel walls travels to the sensor element generating an electrical signal from which an image is reconstructed by an external device, and a moving element for movement of the microchannel structure relative to the sample. Discloses a method for scanning samples whereby the sensor array elements trace parallel paths that are arbitrarily close to the parallel paths traced by other elements of the array.

A Teleo-Reactive Node for Implementing Internet of Things Systems

PubMed Central

Álvarez, Bárbara; Fernández, Diego

2018-01-01

The Internet of Things (IoT) is one of today’s main disruptive technologies and, although massive research has been carried out in recent years, there are still some open issues such as the consideration of software engineering methods and tools. We propose the adoption of the Teleo-Reactive approach in order to facilitate the development of Internet of Things systems as a set of communicating Teleo-Reactive nodes. The software behavior of the nodes is specified in terms of goals, perceptions and actions over the environment, achieving higher abstraction than using general-purpose programming languages and therefore, enhancing the involvement of non-technical users in the specification process. Throughout this paper, we describe the elements of a Teleo-Reactive node and a systematic procedure for translating Teleo-Reactive specifications into executable code for Internet of Things devices. The case study of a robotic agent is used in order to validate the whole approach. PMID:29614772

A Teleo-Reactive Node for Implementing Internet of Things Systems.

PubMed

Sánchez, Pedro; Álvarez, Bárbara; Antolinos, Elías; Fernández, Diego; Iborra, Andrés

2018-04-01

The Internet of Things (IoT) is one of today's main disruptive technologies and, although massive research has been carried out in recent years, there are still some open issues such as the consideration of software engineering methods and tools. We propose the adoption of the Teleo-Reactive approach in order to facilitate the development of Internet of Things systems as a set of communicating Teleo-Reactive nodes. The software behavior of the nodes is specified in terms of goals, perceptions and actions over the environment, achieving higher abstraction than using general-purpose programming languages and therefore, enhancing the involvement of non-technical users in the specification process. Throughout this paper, we describe the elements of a Teleo-Reactive node and a systematic procedure for translating Teleo-Reactive specifications into executable code for Internet of Things devices. The case study of a robotic agent is used in order to validate the whole approach.

Analysis of Network Vulnerability Under Joint Node and Link Attacks

NASA Astrophysics Data System (ADS)

Li, Yongcheng; Liu, Shumei; Yu, Yao; Cao, Ting

2018-03-01

The security problem of computer network system is becoming more and more serious. The fundamental reason is that there are security vulnerabilities in the network system. Therefore, it’s very important to identify and reduce or eliminate these vulnerabilities before they are attacked. In this paper, we are interested in joint node and link attacks and propose a vulnerability evaluation method based on the overall connectivity of the network to defense this attack. Especially, we analyze the attack cost problem from the attackers’ perspective. The purpose is to find the set of least costs for joint links and nodes, and their deletion will lead to serious network connection damage. The simulation results show that the vulnerable elements obtained from the proposed method are more suitable for the attacking idea of the malicious persons in joint node and link attack. It is easy to find that the proposed method has more realistic protection significance.

Feed network and electromagnetic radiation source

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

Ardavan, Arzhang; Singleton, John; Linehan, Kevin E.

An antenna may include a volume polarization current radiator and a feed network. The volume polarization current radiator, includes a dielectric solid (such as a dielectric strip), and a plurality of closely-spaced excitation elements (24), each excitation element (24) being configured to induce a volume polarization current distribution in the dielectric solid proximate to the excitation element when a voltage is applied to the excitation element. The feed network is coupled to the volume polarization current radiator. The feed network also includes a plurality of passive power divider elements (32) and a plurality of passive delay elements (d1-d6) coupling themore » first port (30) and the plurality of second ports (108, 109, 164), the plurality of power divider elements (32) and the plurality of phase delay elements (d1-d6) being configured such that a radio-frequency signal that is applied to the first port (30) experiences a progressive change of phase as it is coupled to the plurality of second ports (108, 109, 164) so as to cause the volume polarization current distribution to propagate along the dielectric solid.« less

Prognostic relevance of an epigenetic biomarker panel in sentinel lymph nodes from colon cancer patients.

PubMed

Lind, Guro E; Guriby, Marianne; Ahlquist, Terje; Hussain, Israr; Jeanmougin, Marine; Søreide, Kjetil; Kørner, Hartwig; Lothe, Ragnhild A; Nordgård, Oddmund

2017-01-01

Patients with early colorectal cancer (stages I-II) generally have a good prognosis, but a subgroup of 15-20% experiences relapse and eventually die of disease. Occult metastases have been suggested as a marker for increased risk of recurrence in patients with node-negative disease. Using a previously identified, highly accurate epigenetic biomarker panel for early detection of colorectal tumors, we aimed at evaluating the prognostic value of occult metastases in sentinel lymph nodes of colon cancer patients. The biomarker panel was analyzed by quantitative methylation-specific PCR in primary tumors and 783 sentinel lymph nodes from 201 patients. The panel status in sentinel lymph nodes showed a strong association with lymph node stage ( P  = 8.2E-17). Compared with routine lymph node diagnostics, the biomarker panel had a sensitivity of 79% (31/39). Interestingly, among 162 patients with negative lymph nodes from routine diagnostics, 13 (8%) were positive for the biomarker panel. Colon cancer patients with high sentinel lymph node methylation had an inferior prognosis (5-year overall survival P  = 3.0E-4; time to recurrence P  = 3.1E-4), although not significant. The same trend was observed in multivariate analyses ( P  = 1.4E-1 and P  = 6.7E-2, respectively). Occult sentinel lymph node metastases were not detected in early stage (I-II) colon cancer patients who experienced relapse. Colon cancer patients with high sentinel lymph node methylation of the analyzed epigenetic biomarker panel had an inferior prognosis, although not significant in multivariate analyses. Occult metastases in TNM stage II patients that experienced relapse were not detected.

The Feasibility and Oncological Safety of Axillary Reverse Mapping in Patients with Breast Cancer: A Systematic Review and Meta-Analysis of Prospective Studies

PubMed Central

Han, Chao; Yang, Ben; Zuo, Wen-Shu; Zheng, Gang; Yang, Li; Zheng, Mei-Zhu

2016-01-01

Objective The axillary reverse mapping (ARM) technique has recently been developed to prevent lymphedema by preserving the arm lymphatic drainage during sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND) procedures. The objective of this systematic review and meta-analysis was to evaluate the feasibility and oncological safety of ARM. Methods We searched Medline, Embase, Web of science, Scopus, and the Cochrane Library for relevant prospective studies. The identification rate of ARM nodes, the crossover rate of SLN-ARM nodes, the proportion of metastatic ARM nodes, and the incidence of complications were pooled into meta-analyses by the random-effects model. Results A total of 24 prospective studies were included into meta-analyses, of which 11 studies reported ARM during SLNB, and 18 studies reported ARM during SLNB. The overall identification rate of ARM nodes was 38.2% (95% CI 32.9%-43.8%) during SLNB and 82.8% (78.0%-86.6%) during ALND, respectively. The crossover rate of SLN-ARM nodes was 19.6% (95% CI 14.4%-26.1%). The metastatic rate of ARM nodes was 16.9% (95% CI 14.2%-20.1%). The pooled incidence of lymphedema was 4.1% (95% CI 2.9–5.9%) for patients undergoing ARM procedure. Conclusions The ARM procedure was feasible during ALND. Nevertheless, it was restricted by low identification rate of ARM nodes during SLNB. ARM was beneficial for preventing lymphedema. However, this technique should be performed with caution given the possibility of crossover SLN-ARM nodes and metastatic ARM nodes. ARM appeared to be unsuitable for patients with clinically positive breast cancer due to oncological safety concern. PMID:26919589

Preclinical Evaluation of Robotic-Assisted Sentinel Lymph Node Fluorescence Imaging

PubMed Central

Liss, Michael A.; Farshchi-Heydari, Salman; Qin, Zhengtao; Hickey, Sean A.; Hall, David J.; Kane, Christopher J.; Vera, David R.

2015-01-01

An ideal substance to provide convenient and accurate targeting for sentinel lymph node (SLN) mapping during robotic-assisted surgery has yet to be found. We used an animal model to determine the ability of the FireFly camera system to detect fluorescent SLNs after administration of a dual-labeled molecular imaging agent. Methods We injected the footpads of New Zealand White rabbits with 1.7 or 8.4 nmol of tilmanocept labeled with 99mTc and a near-infrared fluorophore, IRDye800CW. One and 36 h after injection, popliteal lymph nodes, representing the SLNs, were dissected with the assistance of the FireFly camera system, a fluorescence-capable endoscopic imaging system. After excision of the paraaortic lymph nodes, which represented non-SLNs, we assayed all lymph nodes for radioactivity and fluorescence intensity. Results Fluorescence within all popliteal lymph nodes was easily detected by the FireFly camera system. Fluorescence within the lymph channel could be imaged during the 1-h studies. When compared with the paraaortic lymph nodes, the popliteal lymph nodes retain greater than 95% of the radioactivity at both 1 and 36 h after injection. At both doses (1.7 and 8.4 nmol), the popliteal nodes had higher (P < 0.050) optical fluorescence intensity than the paraaortic nodes at the 1- and 36-h time points. Conclusion The FireFly camera system can easily detect tilmanocept labeled with a near-infrared fluorophore at least 36 h after administration. This ability will permit image acquisition and subsequent verification of fluorescence-labeled SLNs during robotic-assisted surgery. PMID:25024425

Preclinical evaluation of robotic-assisted sentinel lymph node fluorescence imaging.

PubMed

Liss, Michael A; Farshchi-Heydari, Salman; Qin, Zhengtao; Hickey, Sean A; Hall, David J; Kane, Christopher J; Vera, David R

2014-09-01

An ideal substance to provide convenient and accurate targeting for sentinel lymph node (SLN) mapping during robotic-assisted surgery has yet to be found. We used an animal model to determine the ability of the FireFly camera system to detect fluorescent SLNs after administration of a dual-labeled molecular imaging agent. We injected the footpads of New Zealand White rabbits with 1.7 or 8.4 nmol of tilmanocept labeled with (99m)Tc and a near-infrared fluorophore, IRDye800CW. One and 36 h after injection, popliteal lymph nodes, representing the SLNs, were dissected with the assistance of the FireFly camera system, a fluorescence-capable endoscopic imaging system. After excision of the paraaortic lymph nodes, which represented non-SLNs, we assayed all lymph nodes for radioactivity and fluorescence intensity. Fluorescence within all popliteal lymph nodes was easily detected by the FireFly camera system. Fluorescence within the lymph channel could be imaged during the 1-h studies. When compared with the paraaortic lymph nodes, the popliteal lymph nodes retain greater than 95% of the radioactivity at both 1 and 36 h after injection. At both doses (1.7 and 8.4 nmol), the popliteal nodes had higher (P < 0.050) optical fluorescence intensity than the paraaortic nodes at the 1- and 36-h time points. The FireFly camera system can easily detect tilmanocept labeled with a near-infrared fluorophore at least 36 h after administration. This ability will permit image acquisition and subsequent verification of fluorescence-labeled SLNs during robotic-assisted surgery. © 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Intravascular lymphoma with a gastric submucosal tumor.

PubMed

Sawahara, Hiroaki; Iwamuro, Masaya; Ito, Mamoru; Nose, Soichiro; Nishimura, Mamoru; Okada, Hiroyuki

A 75-year-old man was admitted to our hospital for further examination of swollen lymph nodes and a possible gastric submucosal tumor. He had persistent fever and anorexia. Blood examination showed anemia, thrombocytopenia, and elevated lactate dehydrogenase and soluble interleukin 2 receptor levels. Swollen lymph nodes and splenomegaly were evident on computed tomography, and the submucosal tumor was revealed by esophagogastric endoscopy. Cervical lymph node biopsy and endoscopic biopsy were performed, which revealed a diagnosis of intravascular lymphoma. In Asian countries, patients with intravascular lymphoma often have hemophagocytic syndrome without lesions of the central nervous system or skin, which is called the Asian variant of intravascular lymphoma. In this case, the patient had no indicative lesions and had no evidence of the hemophagocytic syndrome. He also had lymph node swelling and a gastric submucosal tumor, which are rare in intravascular lymphoma. The patient was treated with chemotherapy (R-CHOP;rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisolone), and complete response was demonstrated (based on the Response Evaluation Criteria for Solid Tumours [RECIST] guideline). In cases of possible intravascular lymphoma, gastrointestinal endoscopy and biopsy should be considered because they are a useful diagnostic strategy.

Left-right asymmetry in pelvic lymph nodes distribution: is there a right-side prevalence?

PubMed

Ghezzi, Fabio; Cromi, Antonella; Uccella, Stefano; Giudici, Silvia; Franchi, Massimo; Bolis, Pierfrancesco

2006-08-01

To assess whether pelvic lymph nodes have a left-right asymmetric distribution. The oncologic databases of two gynecologic academic departments were used to identify consecutive patients undergoing pelvic systematic lymphadenectomy as part of the treatment for a variety of gynecologic malignancies. All procedures were carried out in a standardized fashion. Lymph node counts were retrieved from pathological reports. Four hundred and twenty-eight women underwent pelvic lymphadenectomy during the study period. The median lymph node count was higher on the right side than on the left side [10 (0-33) versus 8 (0-29); P<0.0001]. A prevalence of right-sided nodes was found in 265 (61.9%) patients, while in 44 (10.3%) cases pelvic nodes were equally distributed on the two sides. The right-sided prevalence was significantly higher than the expected 50% in each type of malignancy and surgical technique subgroup. The right-sided prevalence was statistically significant even when the analysis was performed for different nodal groups [external iliac nodes: 5 (0-23) versus 4 (0-13), P=0.005; hypogastric and obturator nodes: 6 (0-17) versus 5 (0-19), P=0.04]. Moreover, nodal count was higher on the right than on the left in obese [10 (1-33) versus 8 (1-26), P=0.0002] and nonobese women [10 (0-32) versus 9 (0-29), P<0.0001]. Our findings suggest the existence of a left-right asymmetry in pelvic lymph nodes distribution, with right-sided prevalence.

Pelvic lymph node dissection in early ovarian cancer: success of retrieval of lymph nodes by individual lymph node groups in respect to pelvic laterality.

PubMed

Mujezinović, Faris; Takac, Iztok

2010-08-01

To evaluate the differences in number of harvested retroperitoneal pelvic lymph nodes by specific lymph node regions in respect to pelvic laterality. We extracted cases of early ovarian cancer (EOC) with lymphadenectomy from the medical database which were treated at our institution in the period between 1994 and 2008. Recommendations of FIGO and EGSOC (European Guidelines for Staging in Ovarian Cancer) for staging of ovarian malignancies were followed. Stage of the disease was established on the basis of intra-abdominal condition which we found during surgery and histopathologic status of retroperitoneal lymph nodes (LN). For each case and every LN group, we subtracted the number of dissected lymph nodes on the left side from the number of dissected lymph nodes on the right side of the pelvis. The result would represent the difference between number of removed LN on each side of the pelvis for specific LN group. A negative difference means that a greater number of LN was extracted from the left side and a positive difference that the greater number of LN was extracted from the right side of the pelvis. We used Wilcoxon signed-rank test for statistical analysis of differences. 48 cases with EOC underwent lymphadenectomy. In three cases, metastatic retroperitoneal pelvic lymph nodes were found. There were 79.1%, 50.0%, 45.8%, 93.8%, 52.1%, 60.4% and 70.8% of cases with left-right difference in number of removed lymph nodes in external iliac region, common iliac region, presacralic, above obturator nerve, under obturator nerve, lateral from the external ilac vessels and lateral from the common iliac vessels nodal group, respectively. The mean differences between left and right groups were in the range from 2 to 4 lymph nodes. There was no identifiable bias toward either side of the pelvis for any of the analyzed lymph node groups. There is a right and left prevalence of retrieved LN by individual LN regions in the pelvis that could be influenced by asymmetry in right-left pelvic LN distribution. However, we did not find any evidence that the observed imbalance is, on average, directed toward either side of the pelvis. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Propulsion system needs

NASA Technical Reports Server (NTRS)

Gunn, Stanley

1991-01-01

The needs of the designer of a solid core nuclear rocket engine are discussed. Some of the topics covered include: (1) a flight thrust module/feed system module assembly; (2) a nuclear thermal rocket (NTR), expander cycle, dual T/P; (3) turbopump operating conditions; (4) typical system parameters; (5) growth capability composite fuel elements; (6) a NTR radiation cooled nozzle extension; (7) a NFS-3B Feed System; and (8) a NTR Integrated Pneumatic-Fluidics Control System.

Synchronization between uncertain nonidentical networks with quantum chaotic behavior

NASA Astrophysics Data System (ADS)

Li, Wenlin; Li, Chong; Song, Heshan

2016-11-01

Synchronization between uncertain nonidentical networks with quantum chaotic behavior is researched. The identification laws of unknown parameters in state equations of network nodes, the adaptive laws of configuration matrix elements and outer coupling strengths are determined based on Lyapunov theorem. The conditions of realizing synchronization between uncertain nonidentical networks are discussed and obtained. Further, Jaynes-Cummings model in physics are taken as the nodes of two networks and simulation results show that the synchronization performance between networks is very stable.

Integrated scatterometry for tight overlay and CD control to enable 20-nm node wafer manufacturing.

NASA Astrophysics Data System (ADS)

Benschop, Jos; Engelen, Andre; Cramer, Hugo; Kubis, Michael; Hinnen, Paul; van der Laan, Hans; Bhattacharyya, Kaustuve; Mulkens, Jan

2013-04-01

The overlay, CDU and focus requirements for the 20nm node can only be met using a holistic lithography approach whereby full use is made of high-order, field-by-field, scanner correction capabilities. An essential element in this approach is a fast, precise and accurate in-line metrology sensor, capable to measure on product. The capabilities of the metrology sensor as well as the impact on overlay, CD and focus will be shared in this paper.

The application of finite volume methods for modelling three-dimensional incompressible flow on an unstructured mesh

NASA Astrophysics Data System (ADS)

Lonsdale, R. D.; Webster, R.

This paper demonstrates the application of a simple finite volume approach to a finite element mesh, combining the economy of the former with the geometrical flexibility of the latter. The procedure is used to model a three-dimensional flow on a mesh of linear eight-node brick (hexahedra). Simulations are performed for a wide range of flow problems, some in excess of 94,000 nodes. The resulting computer code ASTEC that incorporates these procedures is described.

A User’s/Programmer’s Manual for TWAKE.

DTIC Science & Technology

1988-05-06

subroutines sorted according to primary function Inout OutDut Utjiitv Ean. Solve LDDOEL CALORD GETBAT ASSMAT EDATA COMOC LINKI ASMSQ BDINPT DRVBUG LINK2 BANCHO...beginning at the left most node (no. 1) and continuing to the last node in that row (no. 19). IBORD LEFT 2 BOTTOM 2 RIGHT 2 TOP 2 DONE LINKI 2 T call...LINK1 3 T GEOMFL Call SUBROUTINE NODELM again to compute element thickness and area from data calculated in GEOMFL. LINKI 2 T NODELM Call SUBROUTINE

Field test of wavelength-saving quantum key distribution network.

PubMed

Wang, Shuang; Chen, Wei; Yin, Zhen-Qiang; Zhang, Yang; Zhang, Tao; Li, Hong-Wei; Xu, Fang-Xing; Zhou, Zheng; Yang, Yang; Huang, Da-Jun; Zhang, Li-Jun; Li, Fang-Yi; Liu, Dong; Wang, Yong-Gang; Guo, Guang-Can; Han, Zheng-Fu

2010-07-15

We propose a wavelength-saving topology of a quantum key distribution (QKD) network based on passive optical elements, and we report on the field test of this network on commercial telecom optical fiber at the frequency of 20 MHz. In this network, five nodes are supported with two wavelengths, and every two nodes can share secure keys directly at the same time. We also characterized the insertion loss and cross talk effects on the point-to-point QKD system after introducing this QKD network.

Methods of visualizing graphs

DOEpatents

Wong, Pak C.; Mackey, Patrick S.; Perrine, Kenneth A.; Foote, Harlan P.; Thomas, James J.

2008-12-23

Methods for visualizing a graph by automatically drawing elements of the graph as labels are disclosed. In one embodiment, the method comprises receiving node information and edge information from an input device and/or communication interface, constructing a graph layout based at least in part on that information, wherein the edges are automatically drawn as labels, and displaying the graph on a display device according to the graph layout. In some embodiments, the nodes are automatically drawn as labels instead of, or in addition to, the label-edges.

Material nonlinear analysis via mixed-iterative finite element method

NASA Technical Reports Server (NTRS)

Sutjahjo, Edhi; Chamis, Christos C.

1992-01-01

The performance of elastic-plastic mixed-iterative analysis is examined through a set of convergence studies. Membrane and bending behaviors are tested using 4-node quadrilateral finite elements. The membrane result is excellent, which indicates the implementation of elastic-plastic mixed-iterative analysis is appropriate. On the other hand, further research to improve bending performance of the method seems to be warranted.

2008 Year in Review

NASA Technical Reports Server (NTRS)

Figueroa, Jorge Fernando

2008-01-01

In February of 2008; NASA Stennis Space Center (SSC), NASA Kennedy Space Center (KSC), and The Applied Research Laboratory at Penn State University demonstrated a pilot implementation of an Integrated System Health Management (ISHM) capability at the Launch Complex 20 of KSC. The following significant accomplishments are associated with this development: (1) implementation of an architecture for ground operations ISHM, based on networked intelligent elements; (2) Use of standards for management of data, information, and knowledge (DIaK) leading to modular ISHM implementation with interoperable elements communicating according to standards (three standards were used: IEEE 1451 family of standards for smart sensors and actuators, Open Systems Architecture for Condition Based Maintenance (OSA-CBM) standard for communicating DIaK describing the condition of elements of a system, and the OPC standard for communicating data); (3) ISHM implementation using interoperable modules addressing health management of subsystems; and (4) use of a physical intelligent sensor node (smart network element or SNE capable of providing data and health) along with classic sensors originally installed in the facility. An operational demonstration included detection of anomalies (sensor failures, leaks, etc.), determination of causes and effects, communication among health nodes, and user interfaces.

A review of aqueous foam in microscale.

PubMed

Anazadehsayed, Abdolhamid; Rezaee, Nastaran; Naser, Jamal; Nguyen, Anh V

2018-06-01

In recent years, significant progress has been achieved in the study of aqueous foams. Having said this, a better understanding of foam physics requires a deeper and profound study of foam elements. This paper reviews the studies in the microscale of aqueous foams. The elements of aqueous foams are interior Plateau borders, exterior Plateau borders, nodes, and films. Furthermore, these elements' contribution to the drainage of foam and hydraulic resistance are studied. The Marangoni phenomena that can happen in aqueous foams are listed as Marangoni recirculation in the transition region, Marangoni-driven flow from Plateau border towards the film in the foam fractionation process, and Marangoni flow caused by exposure of foam containing photosurfactants under UV. Then, the flow analysis of combined elements of foam such as PB-film along with Marangoni flow and PB-node are studied. Next, we contrast the behavior of foams in different conditions. These various conditions can be perturbation in the foam structure caused by injected water droplets or waves or using a non-Newtonian fluid to make the foam. Further review is about the effect of oil droplets and particles on the characteristics of foam such as drainage, stability and interfacial mobility. Copyright © 2018 Elsevier B.V. All rights reserved.

An Embedded Statistical Method for Coupling Molecular Dynamics and Finite Element Analyses

NASA Technical Reports Server (NTRS)

Saether, E.; Glaessgen, E.H.; Yamakov, V.

2008-01-01

The coupling of molecular dynamics (MD) simulations with finite element methods (FEM) yields computationally efficient models that link fundamental material processes at the atomistic level with continuum field responses at higher length scales. The theoretical challenge involves developing a seamless connection along an interface between two inherently different simulation frameworks. Various specialized methods have been developed to solve particular classes of problems. Many of these methods link the kinematics of individual MD atoms with FEM nodes at their common interface, necessarily requiring that the finite element mesh be refined to atomic resolution. Some of these coupling approaches also require simulations to be carried out at 0 K and restrict modeling to two-dimensional material domains due to difficulties in simulating full three-dimensional material processes. In the present work, a new approach to MD-FEM coupling is developed based on a restatement of the standard boundary value problem used to define a coupled domain. The method replaces a direct linkage of individual MD atoms and finite element (FE) nodes with a statistical averaging of atomistic displacements in local atomic volumes associated with each FE node in an interface region. The FEM and MD computational systems are effectively independent and communicate only through an iterative update of their boundary conditions. With the use of statistical averages of the atomistic quantities to couple the two computational schemes, the developed approach is referred to as an embedded statistical coupling method (ESCM). ESCM provides an enhanced coupling methodology that is inherently applicable to three-dimensional domains, avoids discretization of the continuum model to atomic scale resolution, and permits finite temperature states to be applied.

A New Concurrent Multiscale Methodology for Coupling Molecular Dynamics and Finite Element Analyses

NASA Technical Reports Server (NTRS)

Yamakov, Vesselin; Saether, Erik; Glaessgen, Edward H/.

2008-01-01

The coupling of molecular dynamics (MD) simulations with finite element methods (FEM) yields computationally efficient models that link fundamental material processes at the atomistic level with continuum field responses at higher length scales. The theoretical challenge involves developing a seamless connection along an interface between two inherently different simulation frameworks. Various specialized methods have been developed to solve particular classes of problems. Many of these methods link the kinematics of individual MD atoms with FEM nodes at their common interface, necessarily requiring that the finite element mesh be refined to atomic resolution. Some of these coupling approaches also require simulations to be carried out at 0 K and restrict modeling to two-dimensional material domains due to difficulties in simulating full three-dimensional material processes. In the present work, a new approach to MD-FEM coupling is developed based on a restatement of the standard boundary value problem used to define a coupled domain. The method replaces a direct linkage of individual MD atoms and finite element (FE) nodes with a statistical averaging of atomistic displacements in local atomic volumes associated with each FE node in an interface region. The FEM and MD computational systems are effectively independent and communicate only through an iterative update of their boundary conditions. With the use of statistical averages of the atomistic quantities to couple the two computational schemes, the developed approach is referred to as an embedded statistical coupling method (ESCM). ESCM provides an enhanced coupling methodology that is inherently applicable to three-dimensional domains, avoids discretization of the continuum model to atomic scale resolution, and permits finite temperature states to be applied.

Finite elements based on consistently assumed stresses and displacements

NASA Technical Reports Server (NTRS)

Pian, T. H. H.

1985-01-01

Finite element stiffness matrices are derived using an extended Hellinger-Reissner principle in which internal displacements are added to serve as Lagrange multipliers to introduce the equilibrium constraint in each element. In a consistent formulation the assumed stresses are initially unconstrained and complete polynomials and the total displacements are also complete such that the corresponding strains are complete in the same order as the stresses. Several examples indicate that resulting properties for elements constructed by this consistent formulation are ideal and are less sensitive to distortions of element geometries. The method has been used to find the optimal stress terms for plane elements, 3-D solids, axisymmetric solids, and plate bending elements.

Precursor routes to quaternary intermetallics: Synthesis, crystal structure, and physical properties of clathrate-II Cs8Na16Al24Si112

NASA Astrophysics Data System (ADS)

Wei, Kaya; Dong, Yongkwan; Nolas, George S.

2016-05-01

A new quaternary clathrate-II composition, Cs8Na16Al24Si112, was synthesized by kinetically controlled thermal decomposition (KCTD) employing both NaSi and NaAlSi as the precursors and CsCl as a reactive flux. The crystal structure and composition of Cs8Na16Al24Si112 were investigated using both Rietveld refinement and elemental analysis, and the temperature dependent transport properties were investigated. Our results indicate that KCTD with multiple precursors is an effective method for the synthesis of multinary inorganic phases that are not easily accessible by traditional solid-state synthesis or crystal growth techniques.

Sentinel lymph node detection in patients with early cervical cancer.

PubMed

Acharya, B C; Jihong, L

2009-01-01

Lymph node status is the most important independent prognostic factor in early stage cervical cancer. Intraoperative lymphatic mapping and sentinel lymph node detection have been increasingly evaluated in the treatment of a variety of solid tumors, particularly breast cancer and cutaneous melanoma. This study evaluated the feasibility of these procedures in patients undergoing radical hysterectomy with pelvic lymphadenectomy for early cervical cancer. A total of 30 patients with histologically diagnosed FIGO stage IA to IIA cervical cancer were enrolled to this study. They were scheduled to undergo radical abdominal hysterectomy and pelvic lymphadenectomy after injecting patent blue dye in cervix. A total of 60 SLNs (mean 2.5) were detected in 24 patients with detection rate of 80%. Bilateral SLNs were detected in 70.1% of cases. SLNs were identified in obturator and external iliac areas in 50% and 31.7%, respectively; no SLNs were discovered in the common iliac region. Seven patients (23.3%) had lymph node metastases; one of these had false negative SLN.The false negative rate and negative predictive value were 14.3% and 94.4%, respectively. SLN detection procedure with blue dye technique is a feasible procedure in cervical cancer. Patent blue dye is cheap, safe and effective tracer to detect sentinel node in carcinoma of cervix.

Modelisation de materiaux composites adaptatifs munis d'actionneurs en alliage a memoire de forme

NASA Astrophysics Data System (ADS)

Simoneau, Charles

Technological development of structures having the capabilities to adapt themselves to different operating conditions is increasing in many areas of research such as aerospace. In fact, numerous works are now oriented toward the design of adaptive aircraft wings where the goal is to enhance the aerodynamic properties of the wing. Following this approach, the work realised in the framework of this master thesis presents the steps leading to the creation of a numerical model that can be used to predict the behavior of an adaptive panel, and therefore, eventually of an adaptive aircraft wing. Foremost, the adaptive panel of this project has been designed from a carbon-epoxy composite, acting as host structure, where shape memory alloy (SMA) wires, acting as actuators, have been inserted in it. SMA actuators have also been embedded asymmetrically along the direction of the panel thickness in order to generate a bending moment when the SMA wires are activated. To achieve the modeling of such structure it has been firstly shown that a numerical model composed of only solid finite elements could be used to represent the panel. However, a second numerical model composed of shell, beam and link finite elements showed that identical results can be obtained with much less nodes (the first model was composed of more than 300 000 nodes compared with 1 000 nodes for the second). The combination of shell-beam-link elements has then been chosen. Secondly, a constitutive relation had to be used for modeling the particular behavior of SMA. For the present work, a uniaxial version of the Likhachev's model is used. Due to its fairly straightforward mathematical formulation, this material law is able to model the main functional properties of SMA including the two-way shape memory effect (TWSME) at zero stress obtained after a thermomechanical education treatment. The last step was to compare the results of the numerical simulations with those obtained with a prototype where 19 actuators were embedded in a composite panel of 425 mm x 425 mm. Various load cases were performed. However, during experimental tests, it has been found that the measured actuator temperature was systematically underestimated. Therefore, by comparing the radius of curvature (rho) of the panel as a function of the activation temperature (T) of the actuators, an offset (in temperature) between the curves numerically and experimentally obtained is observable. Aside from this technological difficulty, the experimental and numerical results are very similar and therefore, this numerical model can be used for predicting the behavior of an adaptive panel. In addition, one the main advantages of this numerical model resides in its versatility where it has been shown that a "warping" of the panel could be realized by controlling independently each actuator. Future works should now obviously focus on the temperature measurement while considering the improvement of the numerical model and the possibility to model an initially curved adaptive panel whose form could resemble an aircraft wing.

Soft-Matter Printed Circuit Board with UV Laser Micropatterning.

PubMed

Lu, Tong; Markvicka, Eric J; Jin, Yichu; Majidi, Carmel

2017-07-05

When encapsulated in elastomer, micropatterned traces of Ga-based liquid metal (LM) can function as elastically deformable circuit wiring that provides mechanically robust electrical connectivity between solid-state elements (e.g., transistors, processors, and sensor nodes). However, LM-microelectronics integration is currently limited by challenges in rapid fabrication of LM circuits and the creation of vias between circuit terminals and the I/O pins of packaged electronics. In this study, we address both with a unique layup for soft-matter electronics in which traces of liquid-phase Ga-In eutectic (EGaIn) are patterned with UV laser micromachining (UVLM). The terminals of the elastomer-sealed LM circuit connect to the surface mounted chips through vertically aligned columns of EGaIn-coated Ag-Fe 2 O 3 microparticles that are embedded within an interfacial elastomer layer. The processing technique is compatible with conventional UVLM printed circuit board (PCB) prototyping and exploits the photophysical ablation of EGaIn on an elastomer substrate. Potential applications to wearable computing and biosensing are demonstrated with functional implementations in which soft-matter PCBs are populated with surface-mounted microelectronics.

A fictitious domain approach for the simulation of dense suspensions

NASA Astrophysics Data System (ADS)

Gallier, Stany; Lemaire, Elisabeth; Lobry, Laurent; Peters, François

2014-01-01

Low Reynolds number concentrated suspensions do exhibit an intricate physics which can be partly unraveled by the use of numerical simulation. To this end, a Lagrange multiplier-free fictitious domain approach is described in this work. Unlike some methods recently proposed, the present approach is fully Eulerian and therefore does not need any transfer between the Eulerian background grid and some Lagrangian nodes attached to particles. Lubrication forces between particles play an important role in the suspension rheology and have been properly accounted for in the model. A robust and effective lubrication scheme is outlined which consists in transposing the classical approach used in Stokesian Dynamics to our present direct numerical simulation. This lubrication model has also been adapted to account for solid boundaries such as walls. Contact forces between particles are modeled using a classical Discrete Element Method (DEM), a widely used method in granular matter physics. Comprehensive validations are presented on various one-particle, two-particle or three-particle configurations in a linear shear flow as well as some O(103) and O(104) particle simulations.

Three-Dimensional, Laminar Flow Past a Short, Surface-Mounted Cylinder

NASA Astrophysics Data System (ADS)

Liakos, Anastasios; Malamataris, Nikolaos

2016-11-01

The topology and evolution of three-dimensional flow past a cylinder of slenderness ratio SR = 1 mounted in a wind tunnel is examined for 0 . 1 <= Re <= 325 (based on the diameter of the cylinder) where steady-state solutions have been obtained. Direct numerical simulations were computed using an in-house parallel finite element code. Results indicate that symmetry breaking occurs at Re = 1 , while the first prominent structure is a horseshoe vortex downstream from the cylinder. At Re = 150 , two foci are observed, indicating the formation of two tornadolike vortices downstream. Concurrently, another horseshoe vortex is formed upstream from the cylinder. For higher Reynolds numbers, the flow downstream is segmented to upper and lower parts, whereas the topology of the flow on the solid boundaries remains unaltered. Pressure distributions show that pressure, the key physical parameter in the flow, decreases everywhere except immediately upstream from the cylinder. In addition, creation of critical points from saddle-node-type bifurcations occur when the streamwise component of the pressure gradient changes sign. Finally, at Re = 325 , an additional horseshoe vorrtex is formed at the wake of the cylinder

Accelerated exploration of multi-principal element alloys with solid solution phases

PubMed Central

Senkov, O.N.; Miller, J.D.; Miracle, D.B.; Woodward, C.

2015-01-01

Recent multi-principal element, high entropy alloy (HEA) development strategies vastly expand the number of candidate alloy systems, but also pose a new challenge—how to rapidly screen thousands of candidate alloy systems for targeted properties. Here we develop a new approach to rapidly assess structural metals by combining calculated phase diagrams with simple rules based on the phases present, their transformation temperatures and useful microstructures. We evaluate over 130,000 alloy systems, identifying promising compositions for more time-intensive experimental studies. We find the surprising result that solid solution alloys become less likely as the number of alloy elements increases. This contradicts the major premise of HEAs—that increased configurational entropy increases the stability of disordered solid solution phases. As the number of elements increases, the configurational entropy rises slowly while the probability of at least one pair of elements favouring formation of intermetallic compounds increases more rapidly, explaining this apparent contradiction. PMID:25739749

Lymph node dissection for melanoma using tumescence local anaesthesia: an observational study.

PubMed

Kofler, Lukas; Breuninger, Helmut; Häfner, Hans-Martin; Schweinzer, Katrin; Schnabl, Saskia M; Eigentler, Thomas K; Leiter, Ulrike

2018-04-01

The possibility that tumescence local anaesthesia (TLA) may lead to dissemination of tumour cells in lymph nodes is presently unclear. To evaluate whether infiltration by TLA influences metastatic spread and survival probability, compared to general anaesthesia (GA), based on lymph node dissection in melanoma patients. In total, 281 patients (GA: 162; TLA: 119) with cutaneous melanoma and clinically or histologically-confirmed metastases in regional lymph nodes were included. All patients underwent complete lymph node dissection. Median follow-up was 70 months. The rate of lymph node recurrence at the dissection site was 25.3% in the GA group and 17.6% in the TLA group (p = 0.082). No significant difference was found concerning 10-year melanoma-specific survival (GA: 56.2%, TLA: 67.4%; p = 0.09), disease-free survival (GA: 72.8 %, TLA: 81.1%; p = 0.095), or lymph node-free survival (GA: 72.8%, TLA: 81.1%; p = 0.095). Distant metastases-free survival appeared to be slightly reduced in the TLA group (GA: 49.9%, TLA: 64.0%; p = 0.025). No differences were identified between the GA and TLA groups regarding prognostic outcome for overall survival or disease-free survival.

Elastic-plastic mixed-iterative finite element analysis: Implementation and performance assessment

NASA Technical Reports Server (NTRS)

Sutjahjo, Edhi; Chamis, Christos C.

1993-01-01

An elastic-plastic algorithm based on Von Mises and associative flow criteria is implemented in MHOST-a mixed iterative finite element analysis computer program developed by NASA Lewis Research Center. The performance of the resulting elastic-plastic mixed-iterative analysis is examined through a set of convergence studies. Membrane and bending behaviors of 4-node quadrilateral shell finite elements are tested for elastic-plastic performance. Generally, the membrane results are excellent, indicating the implementation of elastic-plastic mixed-iterative analysis is appropriate.

Separation Process of Fine Coals by Ultrasonic Vibration Gas-Solid Fluidized Bed

PubMed Central

Wei, Hua; Xie, Weining

2017-01-01

Ultrasonic vibration gas-solid fluidized bed was proposed and introduced to separate fine coals (0.5–0.125 mm fraction). Several technological methods such as XRF, XRD, XPS, and EPMA were used to study the composition of heavy products to evaluate the separation effect. Results show that the ultrasonic vibration force field strengthens the particle separation process based on density when the vibration frequency is 35 kHz and the fluidization number is 1.8. The ash difference between the light and heavy products and the recovery of combustible material obtain the maximum values of 47.30% and 89.59%, respectively. The sulfur content of the heavy product reaches the maximum value of 6.78%. Chemical state analysis of sulfur shows that organic sulfur (-C-S-), sulfate-sulfur (-SO4), and pyrite-sulfur (-S2) are confirmed in the original coal and heavy product. Organic sulfur (-C-S-) is mainly concentrated in the light product, and pyrite-sulfur (-S2) is significantly enriched in the heavy product. The element composition, phase composition, backscatter imagery, and surface distribution of elements for heavy product show concentration of high-density minerals including pyrite, quartz, and kaolinite. Some harmful elements such as F, Pb, and As are also concentrated in the heavy product. PMID:28845160

Development and Characterization of Edible Films Based on Fruit and Vegetable Residues.

PubMed

Andrade, Roberta M S; Ferreira, Mariana S L; Gonçalves, Édira C B A

2016-02-01

Edible films were developed from the solid residue of the processing of whole fruits and vegetables. The solid residue, processed into flour (FVR flour) was chemically and structurally characterized by microstructure, elemental composition, structural links, and moisture sorption isotherm. Films were prepared by casting using aqueous extracts of 8% and 10% of flour (w/w) and characterized in terms of thickness, water solubility, mechanical properties, water vapor permeability, and Fourier transform infrared (FTIR). The analysis of microstructure and elemental composition, performed on flour (mean particle size 350 μm), showed an essentially granular aspect, with the presence of fibrous particles having potassium as one of the most abundant elements. FTIR results showed similarity between the characteristic bands of other raw materials used in edible films. The sorption isotherm of FVR flour showed a typical profile of foods rich in soluble components, such as sugars. Dried films presented an average thickness of 0.263 ± 0.003 mm, a homogenous aspect, bright yellow color, pronounced fruit flavor, and high water solubility. The FTIR spectra of the edible films revealed that addition of potato skin flour did not change the molecular conformation. Moreover, the films presented low tensile strength at break when compared with fruit starch-based films. © 2016 Institute of Food Technologists®

Quantum teleportation between remote atomic-ensemble quantum memories.

PubMed

Bao, Xiao-Hui; Xu, Xiao-Fan; Li, Che-Ming; Yuan, Zhen-Sheng; Lu, Chao-Yang; Pan, Jian-Wei

2012-12-11

Quantum teleportation and quantum memory are two crucial elements for large-scale quantum networks. With the help of prior distributed entanglement as a "quantum channel," quantum teleportation provides an intriguing means to faithfully transfer quantum states among distant locations without actual transmission of the physical carriers [Bennett CH, et al. (1993) Phys Rev Lett 70(13):1895-1899]. Quantum memory enables controlled storage and retrieval of fast-flying photonic quantum bits with stationary matter systems, which is essential to achieve the scalability required for large-scale quantum networks. Combining these two capabilities, here we realize quantum teleportation between two remote atomic-ensemble quantum memory nodes, each composed of ∼10(8) rubidium atoms and connected by a 150-m optical fiber. The spin wave state of one atomic ensemble is mapped to a propagating photon and subjected to Bell state measurements with another single photon that is entangled with the spin wave state of the other ensemble. Two-photon detection events herald the success of teleportation with an average fidelity of 88(7)%. Besides its fundamental interest as a teleportation between two remote macroscopic objects, our technique may be useful for quantum information transfer between different nodes in quantum networks and distributed quantum computing.

Characteristics of a four element gyromagnetic nonlinear transmission line array high power microwave source.

PubMed

Johnson, J M; Reale, D V; Krile, J T; Garcia, R S; Cravey, W H; Neuber, A A; Dickens, J C; Mankowski, J J

2016-05-01

In this paper, a solid-state four element array gyromagnetic nonlinear transmission line high power microwave system is presented as well as a detailed description of its subsystems and general output capabilities. This frequency agile S-band source is easily adjusted from 2-4 GHz by way of a DC driven biasing magnetic field and is capable of generating electric fields of 7.8 kV/m at 10 m correlating to 4.2 MW of RF power with pulse repetition frequencies up to 1 kHz. Beam steering of the array at angles of ±16.7° is also demonstrated, and the associated general radiation pattern is detailed.

Characteristics of a four element gyromagnetic nonlinear transmission line array high power microwave source

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

Johnson, J. M., E-mail: jared.johnson@ttu.edu; Reale, D. V.; Garcia, R. S.

2016-05-15

In this paper, a solid-state four element array gyromagnetic nonlinear transmission line high power microwave system is presented as well as a detailed description of its subsystems and general output capabilities. This frequency agile S-band source is easily adjusted from 2-4 GHz by way of a DC driven biasing magnetic field and is capable of generating electric fields of 7.8 kV/m at 10 m correlating to 4.2 MW of RF power with pulse repetition frequencies up to 1 kHz. Beam steering of the array at angles of ±16.7° is also demonstrated, and the associated general radiation pattern is detailed.

Evaluation of the JPL X-band 32 element active array. [for deep space communication

NASA Technical Reports Server (NTRS)

Boreham, J. F.; Postal, R. B.; Conroy, B. L.

1979-01-01

Tests performed on an X-band 32-element active array are described. Antenna pattern characteristics of the array were tested in its standard operating mode as well as several degraded performance modes, including failures of 1, 2, 3, 4, 8, 16, and 31 elements. Additionally, the array was characterized with the addition of a metallic shroud, and also characterized versus rf drive level and at a single off-axis electronic beamsteered position. Characterization was performed on several of the 3/4-watt, three-stage, X-band solid-state power amplifier modules. The characterization included swept amplitude response, amplitude and phase versus temperature from -20 to +60 C, and intermodulation distortion of selected modules. The array is described and conclusions and recommendations based upon the experience and results achieved are included.

Evaluation of Heavy Metals in Solid Waste Disposal Sites in Campinas City, Brazil Using Synchrotron Radiation Total Reflection X-Ray Fluorescence

NASA Astrophysics Data System (ADS)

de Faria, Bruna Fernanda; Moreira, Silvana

2011-12-01

The problem of solid waste in most countries is on the rise as a result of rapid population growth, urbanization, industrial development and changes in consumption habits. Amongst the various forms of waste disposals, landfills are today the most viable for the Brazilian reality, both technically and economically. Proper landfill construction practices allow minimizing the effects of the two main sources of pollution from solid waste: landfill gas and slurry. However, minimizing is not synonymous with eliminating; consequently, the landfill alone cannot resolve all the problems with solid waste disposal. The main goal of this work is to evaluate the content of trace elements in samples of groundwater, surface water and slurry arising from local solid waste disposals in the city of Campinas, SP, Brazil. Samples were collected at the Delta, Santa Barbara and Pirelli landfills. At the Delta and Santa Barbara sites, values above the maximum permitted level established by CETESB for Cr, Mn, Fe, Ni and Pb were observed in samples of groundwater, while at the Pirelli site, elements with concentrations above the permitted levels were Mn, Fe, Ba and Pb. At Delta, values above levels permitted by the CONAMA 357 legislation were still observed in surface water samples for Cr, Mn, Fe and Cu, whereas in slurry samples, values above the permitted levels were observed for Cr, Mn, Fe, Ni, Cu, Zn and Pb. Slurry samples were prepared in accordance with two extraction methodologies, EPA 3050B and EPA 200.8. Concentrations of Cr, Ni, Cu and Pb were higher than the limit established by CONAMA 357 for most samples collected at different periods (dry and rainy) and also for the two extraction methodologies employed.

Evaluation of Solid Modeling Software for Finite Element Analysis of Woven Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Nemeth, Noel N.; Mital, Subodh; Lang, Jerry

2010-01-01

Three computer programs, used for the purpose of generating 3-D finite element models of the Repeating Unit Cell (RUC) of a textile, were examined for suitability to model woven Ceramic Matrix Composites (CMCs). The programs evaluated were the open-source available TexGen, the commercially available WiseTex, and the proprietary Composite Material Evaluator (COMATE). A five-harness-satin (5HS) weave for a melt-infiltrated (MI) silicon carbide matrix and silicon carbide fiber was selected as an example problem and the programs were tested for their ability to generate a finite element model of the RUC. The programs were also evaluated for ease-of-use and capability, particularly for the capability to introduce various defect types such as porosity, ply shifting, and nesting of a laminate. Overall, it was found that TexGen and WiseTex were useful for generating solid models of the tow geometry; however, there was a lack of consistency in generating well-conditioned finite element meshes of the tows and matrix. TexGen and WiseTex were both capable of allowing collective and individual shifting of tows within a ply and WiseTex also had a ply nesting capability. TexGen and WiseTex were sufficiently userfriendly and both included a Graphical User Interface (GUI). COMATE was satisfactory in generating a 5HS finite element mesh of an idealized weave geometry but COMATE lacked a GUI and was limited to only 5HS and 8HS weaves compared to the larger amount of weave selections available with TexGen and WiseTex.

AUTOSENSITIZATION REACTION IN VITRO

PubMed Central

Koprowski, Hilary; Fernandes, Mario V.

1962-01-01

Lymph node cells were obtained from an inbred strain of Lewis rats injected with guinea pig cord tissue in Freund's adjuvant. These cells, when added to tissue culture monolayers of puppy brain, aggregated on or around the glial elements. This reaction, called contactual agglutination, was followed by the specific destruction of glial cells, leaving cultures consisting only of fibroblasts. No such reaction was noted when lymph node cells obtained either from normal rats or those injected with adjuvant alone were used. Absorption of serum obtained from rats injected with guinea pig cord tissue by non-sensitized lymph node cells made them reactive in brain tissue culture. The contactual agglutination test seems to provide an opportunity for investigation of sensitization reaction in tissue culture systems. PMID:14034719

Three-dimensional separation and reattachment

NASA Technical Reports Server (NTRS)

Peake, D. J.; Tobak, M.

1982-01-01

The separation of three dimensional turbulent boundary layers from the lee of flight vehicles at high angles of attack is investigated. The separation results in dominant, large scale, coiled vortex motions that pass along the body in the general direction of the free stream. In all cases of three dimensional flow separation and reattachment, the assumption of continuous vector fields of skin friction lines and external flow streamlines, coupled with simple laws of topology, provides a flow grammar whose elemental constituents are the singular points: the nodes, spiral nodes (foci), and saddles. The phenomenon of three dimensional separation may be construed as either a local or a global event, depending on whether the skin friction line that becomes a line of separation originates at a node or a saddle point.

Split Node and Stress Glut Methods for Dynamic Rupture Simulations in Finite Elements.

NASA Astrophysics Data System (ADS)

Ramirez-Guzman, L.; Bielak, J.

2008-12-01

I present two numerical techniques to solve the Dynamic problem. I revisit and modify the Split Node approach and introduce a Stress Glut type Method. Both algorithms are implemented using a iso/sub- parametric FEM solver. In the first case, I discuss the formulation and perform an analysis of convergence for different orders of approximation for the acoustic case. I describe the algorithm of the second methodology as well as the assumptions made. The key to the new technique is to have an accurate representation of the traction. Thus, I devote part of the discussion to analyze the tractions for a simple example. The sensitivity of the method is tested by comparing against Split Node solutions.

Prognostic value of lymph node involvement in oral cancers: a study of 137 cases.

PubMed

Tankéré, F; Camproux, A; Barry, B; Guedon, C; Depondt, J; Gehanno, P

2000-12-01

The aim of this study was to assess the prognostic value of lymph node involvement in patients with squamous cell carcinoma of the oral cavity. Retrospective study of 137 patients with T4 squamous cell carcinoma of the oral cavity treated by surgery and radiotherapy (84 N0, 23 N1, 16 N2,14 N3). Twenty-three patients in the N0 group had a history of surgery or radiotherapy. One hundred fourteen patients underwent limited or radical neck dissection unilaterally or bilaterally. The histological charts were reviewed and correlated with preoperative lymph node clinical stage. The local failure rate and the overall survival curves were calculated with respect to clinical and histological stages. The causes of death were analyzed. No evidence of lymph node metastasis was found in 47.4% of cases (54 of 114 patients). Among the node-positive (N+) patients, 39 had rupture of the lymph node capsule (R+). In the N0 group, 27.8% of patients were N+. Regional control rates after surgery and radiotherapy were 95% at 1 year and 85.4% at 5 years. The local failure rates were 6% in N0, 8.7% in N1, 31.2% in N2, 51.7% in N3, 9% in node-negative (N-), and 29% in N+R+ patients. The overall survival rates at 3 and 5 years were, respectively, 44.7% and 34.8% in the N0 group, 37.7% and 37.7% (same rate at 3 and 5 years) in the N1 group, and 31.2% and 15.8% in the N2 group. None of the patients in the N3 group survived beyond 2 years. The overall survival rates at 5 years were 42.8% and 17.5% in the N- and N+ groups, respectively. In patients with locally advanced tumors (T4), clinical nodal status and histological nodal invasion were key prognostic factors. The presence of occult metastases in the N0 group justifies routine neck dissection.

Uncovering Randomness and Success in Society

PubMed Central

Jalan, Sarika; Sarkar, Camellia; Madhusudanan, Anagha; Dwivedi, Sanjiv Kumar

2014-01-01

An understanding of how individuals shape and impact the evolution of society is vastly limited due to the unavailability of large-scale reliable datasets that can simultaneously capture information regarding individual movements and social interactions. We believe that the popular Indian film industry, “Bollywood”, can provide a social network apt for such a study. Bollywood provides massive amounts of real, unbiased data that spans more than 100 years, and hence this network has been used as a model for the present paper. The nodes which maintain a moderate degree or widely cooperate with the other nodes of the network tend to be more fit (measured as the success of the node in the industry) in comparison to the other nodes. The analysis carried forth in the current work, using a conjoined framework of complex network theory and random matrix theory, aims to quantify the elements that determine the fitness of an individual node and the factors that contribute to the robustness of a network. The authors of this paper believe that the method of study used in the current paper can be extended to study various other industries and organizations. PMID:24533073

Stanford Hardware Development Program

NASA Technical Reports Server (NTRS)

Peterson, A.; Linscott, I.; Burr, J.

1986-01-01

Architectures for high performance, digital signal processing, particularly for high resolution, wide band spectrum analysis were developed. These developments are intended to provide instrumentation for NASA's Search for Extraterrestrial Intelligence (SETI) program. The real time signal processing is both formal and experimental. The efficient organization and optimal scheduling of signal processing algorithms were investigated. The work is complemented by efforts in processor architecture design and implementation. A high resolution, multichannel spectrometer that incorporates special purpose microcoded signal processors is being tested. A general purpose signal processor for the data from the multichannel spectrometer was designed to function as the processing element in a highly concurrent machine. The processor performance required for the spectrometer is in the range of 1000 to 10,000 million instructions per second (MIPS). Multiple node processor configurations, where each node performs at 100 MIPS, are sought. The nodes are microprogrammable and are interconnected through a network with high bandwidth for neighboring nodes, and medium bandwidth for nodes at larger distance. The implementation of both the current mutlichannel spectrometer and the signal processor as Very Large Scale Integration CMOS chip sets was commenced.

Uncovering randomness and success in society.

PubMed

Jalan, Sarika; Sarkar, Camellia; Madhusudanan, Anagha; Dwivedi, Sanjiv Kumar

2014-01-01

An understanding of how individuals shape and impact the evolution of society is vastly limited due to the unavailability of large-scale reliable datasets that can simultaneously capture information regarding individual movements and social interactions. We believe that the popular Indian film industry, "Bollywood", can provide a social network apt for such a study. Bollywood provides massive amounts of real, unbiased data that spans more than 100 years, and hence this network has been used as a model for the present paper. The nodes which maintain a moderate degree or widely cooperate with the other nodes of the network tend to be more fit (measured as the success of the node in the industry) in comparison to the other nodes. The analysis carried forth in the current work, using a conjoined framework of complex network theory and random matrix theory, aims to quantify the elements that determine the fitness of an individual node and the factors that contribute to the robustness of a network. The authors of this paper believe that the method of study used in the current paper can be extended to study various other industries and organizations.

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

Frayce, D.; Khayat, R.E.; Derdouri, A.

The dual reciprocity boundary element method (DRBEM) is implemented to solve three-dimensional transient heat conduction problems in the presence of arbitrary sources, typically as these problems arise in materials processing. The DRBEM has a major advantage over conventional BEM, since it avoids the computation of volume integrals. These integrals stem from transient, nonlinear, and/or source terms. Thus there is no need to discretize the inner domain, since only a number of internal points are needed for the computation. The validity of the method is assessed upon comparison with results from benchmark problems where analytical solutions exist. There is generally goodmore » agreement. Comparison against finite element results is also favorable. Calculations are carried out in order to assess the influence of the number and location of internal nodes. The influence of the ratio of the numbers of internal to boundary nodes is also examined.« less

An Implementation of the Salt-Farm Monitoring System Using Wireless Sensor Network

NASA Astrophysics Data System (ADS)

Ju, Jonggil; Park, Ingon; Lee, Yongwoong; Cho, Jongsik; Cho, Hyunwook; Yoe, Hyun; Shin, Changsun

In producing solar salt, natural environmental factors such as temperature, humidity, solar radiation, wind direction, wind speed and rain are essential elements which influence on the productivity and quality of salt. If we can manage the above mentioned environmental elements efficiently, we could achieve improved results in production of salt with good quality. To monitor and manage the natural environments, this paper suggests the Salt-Farm Monitoring System (SFMS) which is operated with renewable energy power. The system collects environmental factors directly from the environmental measure sensors and the sensor nodes. To implement a stand-alone system, we applied solar cell and wind generator to operate this system. Finally, we showed that the SFMS could monitor the salt-farm environments by using wireless sensor nodes and operate correctly without external power supply.

Cubature versus Fekete-Gauss nodes for spectral element methods on simplicial meshes

NASA Astrophysics Data System (ADS)

Pasquetti, Richard; Rapetti, Francesca

2017-10-01

In a recent JCP paper [9], a higher order triangular spectral element method (TSEM) is proposed to address seismic wave field modeling. The main interest of this TSEM is that the mass matrix is diagonal, so that an explicit time marching becomes very cheap. This property results from the fact that, similarly to the usual SEM (say QSEM), the basis functions are Lagrange polynomials based on a set of points that shows both nice interpolation and quadrature properties. In the quadrangle, i.e. for the QSEM, the set of points is simply obtained by tensorial product of Gauss-Lobatto-Legendre (GLL) points. In the triangle, finding such an appropriate set of points is however not trivial. Thus, the work of [9] follows anterior works that started in 2000's [2,6,11] and now provides cubature nodes and weights up to N = 9, where N is the total degree of the polynomial approximation. Here we wish to evaluate the accuracy of this cubature nodes TSEM with respect to the Fekete-Gauss one, see e.g.[12], that makes use of two sets of points, namely the Fekete points and the Gauss points of the triangle for interpolation and quadrature, respectively. Because the Fekete-Gauss TSEM is in the spirit of any nodal hp-finite element methods, one may expect that the conclusions of this Note will remain relevant if using other sets of carefully defined interpolation points.

Sentinel nodes identified by computed tomography-lymphography accurately stage the axilla in patients with breast cancer

PubMed Central

2013-01-01

Background Sentinel node biopsy often results in the identification and removal of multiple nodes as sentinel nodes, although most of these nodes could be non-sentinel nodes. This study investigated whether computed tomography-lymphography (CT-LG) can distinguish sentinel nodes from non-sentinel nodes and whether sentinel nodes identified by CT-LG can accurately stage the axilla in patients with breast cancer. Methods This study included 184 patients with breast cancer and clinically negative nodes. Contrast agent was injected interstitially. The location of sentinel nodes was marked on the skin surface using a CT laser light navigator system. Lymph nodes located just under the marks were first removed as sentinel nodes. Then, all dyed nodes or all hot nodes were removed. Results The mean number of sentinel nodes identified by CT-LG was significantly lower than that of dyed and/or hot nodes removed (1.1 vs 1.8, p <0.0001). Twenty-three (12.5%) patients had ≥2 sentinel nodes identified by CT-LG removed, whereas 94 (51.1%) of patients had ≥2 dyed and/or hot nodes removed (p <0.0001). Pathological evaluation demonstrated that 47 (25.5%) of 184 patients had metastasis to at least one node. All 47 patients demonstrated metastases to at least one of the sentinel nodes identified by CT-LG. Conclusions CT-LG can distinguish sentinel nodes from non-sentinel nodes, and sentinel nodes identified by CT-LG can accurately stage the axilla in patients with breast cancer. Successful identification of sentinel nodes using CT-LG may facilitate image-based diagnosis of metastasis, possibly leading to the omission of sentinel node biopsy. PMID:24321242

Using Large-Scale Roughness Elements to Control Sand and Dust Flux at the Keeler Dunes, Keeler, CA

NASA Astrophysics Data System (ADS)

Gillies, John; McCarley-Holder, Grace

2014-05-01

Controlling dust emission from areas that subsequently degrade air quality and threaten human and animal health and reduce the quality of life for people residing in proximity to such sources is necessary, but also challenging. Recent research has indicated that arrays of large roughness elements (height >0.3 m) can be used effectively to modulate sand transport and the associated dust emissions. Prediction of the rate of sand flux reduction as a function of downwind distance upon entering an array of roughness elements, and the equilibrium flux reduction in the interior of the array is possible using the known geometric properties of the roughness elements, their number, and published relationships. Air quality in the town of Keeler, CA (36 deg 29' 17.92" N, 117 deg 52' 24.62" W) is degraded by levels of particulate matter <10 µm aerodynamic diameter (PM10) during periods of elevated wind speeds due to sand transport and dust emissions in the nearby Keeler Dunes. A demonstration project was designed to evaluate the effectiveness of an array of roughness elements composed of solid elements and managed vegetation to meet sand and dust flux reduction criteria. This project has two major goals: 1) to demonstrate that solid roughness elements placed on areas of the Keeler Dunes immediately arrest sand movement to specified levels (target of 85% reduction), and 2) to assess whether native plant species, planted in the sheltered area of the solid roughness elements can effectively thrive and subsequently replace the solid roughness to achieve the desired sand flux reduction control efficiency. This poster describes the results related mostly to objective one, as considerable time has to pass before sufficient data will be obtained to evaluate the success of the planted and managed vegetation to achieve a control level provided by the solid element roughness array.

Simulation of Semi-Solid Material Mechanical Behavior Using a Combined Discrete/Finite Element Method

NASA Astrophysics Data System (ADS)

Sistaninia, M.; Phillion, A. B.; Drezet, J.-M.; Rappaz, M.

2011-01-01

As a necessary step toward the quantitative prediction of hot tearing defects, a three-dimensional stress-strain simulation based on a combined finite element (FE)/discrete element method (DEM) has been developed that is capable of predicting the mechanical behavior of semisolid metallic alloys during solidification. The solidification model used for generating the initial solid-liquid structure is based on a Voronoi tessellation of randomly distributed nucleation centers and a solute diffusion model for each element of this tessellation. At a given fraction of solid, the deformation is then simulated with the solid grains being modeled using an elastoviscoplastic constitutive law, whereas the remaining liquid layers at grain boundaries are approximated by flexible connectors, each consisting of a spring element and a damper element acting in parallel. The model predictions have been validated against Al-Cu alloy experimental data from the literature. The results show that a combined FE/DEM approach is able to express the overall mechanical behavior of semisolid alloys at the macroscale based on the morphology of the grain structure. For the first time, the localization of strain in the intergranular regions is taken into account. Thus, this approach constitutes an indispensible step towards the development of a comprehensive model of hot tearing.

Analysis of shear buckling of cylindrical shells. II - Effects of combined loadings

NASA Astrophysics Data System (ADS)

Kokubo, Kunio; Nagashima, Hideaki; Takayanagi, Masaaki; Madokoro, Manabu; Mochizuki, Akira; Ikeuchi, Hisaaki

1992-03-01

Cylindrical shells subjected to lateral loads buckle in shear or bending buckling modes. The effects of combined loadings are investigated by developing a special-purpose FEM program using the 8-node isoparametric shell element. Three types of loading, lateral and axial loads, and pure bending moments are considered. For short cylindrical shells, shear buckling modes are dominant, but elephant-foot bulges take place with an increase in bending moments. Effects of axial loads on shear buckling and the elephant-foot bulge are investigated. In the case of shear buckling the axial load affects the buckling mode as well as the buckling load. For bending bucklings, the axial loads have a great effect on the buckling load.

Spin Solid versus Magnetic Charge Ordered State in Artificial Honeycomb Lattice of Connected Elements

PubMed Central

Glavic, Artur; Summers, Brock; Dahal, Ashutosh; Kline, Joseph; Van Herck, Walter; Sukhov, Alexander; Ernst, Arthur

2018-01-01

Abstract The nature of magnetic correlation at low temperature in two‐dimensional artificial magnetic honeycomb lattice is a strongly debated issue. While theoretical researches suggest that the system will develop a novel zero entropy spin solid state as T → 0 K, a confirmation to this effect in artificial honeycomb lattice of connected elements is lacking. This study reports on the investigation of magnetic correlation in newly designed artificial permalloy honeycomb lattice of ultrasmall elements, with a typical length of ≈12 nm, using neutron scattering measurements and temperature‐dependent micromagnetic simulations. Numerical modeling of the polarized neutron reflectometry data elucidates the temperature‐dependent evolution of spin correlation in this system. As temperature reduces to ≈7 K, the system tends to develop novel spin solid state, manifested by the alternating distribution of magnetic vortex loops of opposite chiralities. Experimental results are complemented by temperature‐dependent micromagnetic simulations that confirm the dominance of spin solid state over local magnetic charge ordered state in the artificial honeycomb lattice with connected elements. These results enable a direct investigation of novel spin solid correlation in the connected honeycomb geometry of 2D artificial structure. PMID:29721429

The first octahedral cluster complexes with terminal formate ligands: synthesis, structure, and properties of K4[Re6S8(HCOO)6] and Cs4[Re6S8(HCOO)6].

PubMed

Brylev, Konstantin A; Mironov, Yuri V; Kozlova, Svetlana G; Fedorov, Vladimir E; Kim, Sung-Jin; Pietzsch, Hans-Jürgen; Stephan, Holger; Ito, Akitaka; Ishizaka, Shoji; Kitamura, Noboru

2009-03-02

The hexarhenium anionic cluster complex with terminal formate ligands [Re6S8(HCOO)6]4- was obtained by the room-temperature reaction between [Re6S8(OH)6]4- and formic acid in an aqueous solution. The cluster was crystallized as a potassium or cesium salt and characterized by X-ray single-crystal diffraction and elemental analyses, IR, 1H NMR, UV/vis, and luminescence spectroscopies. In particular, the emission quantum yield of the potassium salt of the Re6 cluster anion in the solid phase was determined for the first time. The electronic structures of [Re6S8(HCOO)6]4- and [Re6S8(OH)6]4- were also elucidated by DFT calculations.

Determination of copper and mercury in phosphate fertilizers employing direct solid sampling analysis and high resolution continuum source graphite furnace atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

de Oliveira Souza, Sidnei; François, Luciane Luiza; Borges, Aline Rocha; Vale, Maria Goreti Rodrigues; Araujo, Rennan Geovanny Oliveira

2015-12-01

The present study proposes the determination of copper and mercury in phosphate fertilizers by direct solid sampling analysis (SS) employing high resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS). For Cu determination, two analytical lines were used: 327.3960 nm and 249.2146 nm. Hg determination was carried out on the line 253.6521 nm and 100 μg KMnO4 was used as chemical modifier. The optimal pyrolysis temperature for Cu determination was 1300 °C. Atomization temperatures for Cu and Hg were 2400 and 1100 °C, respectively. External calibration with aqueous standard solutions was adopted for both elements. The limits of quantification (LoQs) and characteristic mass (m0) obtained for Cu determination were 0.4 μg g- 1 and 1.12 ng, respectively, on line 249.2146 nm, and 64 μg g- 1 and 25 pg on 327.3960 nm. For mercury, LoQ and m0 were 4.8 ng g- 1 and 39 pg, respectively. The accuracy of the proposed methods was confirmed by the analysis of standard reference material (SRM) of Trace Elements in Multi-Nutrient Fertilizer (SRM NIST 695). The precision expressed as relative standard deviation (RSD), was better than 8.2% for Hg and 7.7% for the Cu (n = 5), considered satisfactory for microanalysis in solid sample. Four fertilizer samples acquired in commercial establishments in the city of Salvador, Bahia, Brazil, were analyzed. The optimized analytical methods were simple, fast, accurate, precise and free of spectral interferences for the determination of Cu and Hg in phosphate fertilizer samples by SS-HR-CS GF AAS, avoiding the dissolution of the sample, the use of harmful reagents and the generation of residues.

Finite element model predictions of static deformation from dislocation sources in a subduction zone: Sensitivities to homogeneous, isotropic, Poisson-solid, and half-space assumptions

USGS Publications Warehouse

Masterlark, Timothy

2003-01-01

Dislocation models can simulate static deformation caused by slip along a fault. These models usually take the form of a dislocation embedded in a homogeneous, isotropic, Poisson-solid half-space (HIPSHS). However, the widely accepted HIPSHS assumptions poorly approximate subduction zone systems of converging oceanic and continental crust. This study uses three-dimensional finite element models (FEMs) that allow for any combination (including none) of the HIPSHS assumptions to compute synthetic Green's functions for displacement. Using the 1995 Mw = 8.0 Jalisco-Colima, Mexico, subduction zone earthquake and associated measurements from a nearby GPS array as an example, FEM-generated synthetic Green's functions are combined with standard linear inverse methods to estimate dislocation distributions along the subduction interface. Loading a forward HIPSHS model with dislocation distributions, estimated from FEMs that sequentially relax the HIPSHS assumptions, yields the sensitivity of predicted displacements to each of the HIPSHS assumptions. For the subduction zone models tested and the specific field situation considered, sensitivities to the individual Poisson-solid, isotropy, and homogeneity assumptions can be substantially greater than GPS. measurement uncertainties. Forward modeling quantifies stress coupling between the Mw = 8.0 earthquake and a nearby Mw = 6.3 earthquake that occurred 63 days later. Coulomb stress changes predicted from static HIPSHS models cannot account for the 63-day lag time between events. Alternatively, an FEM that includes a poroelastic oceanic crust, which allows for postseismic pore fluid pressure recovery, can account for the lag time. The pore fluid pressure recovery rate puts an upper limit of 10-17 m2 on the bulk permeability of the oceanic crust. Copyright 2003 by the American Geophysical Union.

Use of 99mTc-Tilmanocept as a Single Agent for Sentinel Lymph Node Identification in Breast Cancer: A Retrospective Pilot Study.

PubMed

Unkart, Jonathan T; Wallace, Anne M

2017-09-01

99m Tc-tilmanocept received recent Food and Drug Administration approval for lymphatic mapping in 2013. However, to our knowledge, no prior studies have evaluated the use of 99m Tc-tilmanocept as a single agent in sentinel lymph node (SLN) biopsy in breast cancer. Methods: We executed this retrospective pilot study to assess the ability of 99m Tc-tilmanocept to identify sentinel nodes as a single agent in clinically node-negative breast cancer patients. Patients received a single intradermal injection overlying the tumor of either 18.5 MBq (0.5 mCi) of 99m Tc-tilmanocept on the day of surgery or 74.0 MBq (2.0 mCi) on the day before surgery by a radiologist. Immediate 3-view lymphoscintigraphy was performed. Intraoperatively, SLNs were identified with a portable γ-probe. A node was classified as hot if the count (per second) of the node was more than 3 times the background count. Descriptive statistics are reported. Results: Nineteen patients underwent SLN biopsy with single-agent 99m Tc-tilmanocept. Immediate lymphoscintigraphy identified at least 1 sentinel node in 13 of 17 patients (76.5%). Intraoperatively, at least 1 (mean, 1.7 ± 0.8; range, 1-3) hot node was identified in all patients. Three patients (15.8%) had 1 disease-positive SLN. Conclusion: In this small, retrospective pilot study, 99m Tc-tilmanocept performed well as a single agent for intraoperative sentinel node identification in breast cancer. A larger, randomized clinical trial is warranted to compare 99m Tc-tilmanocept as a single agent with other radiopharmaceuticals for sentinel node identification in breast cancer. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Determining Which Patients Require Irradiation of the Supraclavicular Nodal Area After Surgery for N1 Breast Cancer

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

Yu, Jeong Il; Park, Won, E-mail: wonp68@skku.ed; Huh, Seung Jae

2010-11-15

Purpose: We designed this study to determine which patients have a high risk of supraclavicular node recurrence in N1 breast cancer previously treated with surgery but not having received supraclavicular radiation therapy (SCRT) and to identify which patients needed SCRT. Methods and Materials: We performed a retrospective review of 448 pathologic N1 breast cancer patients treated with mastectomy or breast-conserving treatment, but without SCRT, between 1994 and 2003. Mastectomy was performed in 302 patients (67.4%). The median number of axillary nodes dissected was 17 (range, 5-53). Systemic chemotherapy was administered in 443 patients (98.9%), and 144 patients received radiation aftermore » breast-conserving surgery. The median follow-up was 88 months (range, 15-170 months). Results: At follow-up, the treatment failed in 101 patients (22.5%), and 39 patients (8.7%) had supraclavicular node recurrence. Prognostic factors in supraclavicular node recurrence included lymphovascular invasion (p < 0.0001), extracapsular extension (p < 0.0001), the number of involved axillary nodes (p = 0.0003), and the level of involved axillary nodes (p = 0.012) in univariate and multivariate analyses. The total number of prognostic factors correlated well with supraclavicular node recurrence. In the analysis of 5-year supraclavicular node recurrence-free survival, patients with two or more factors showed a significantly higher recurrence rate than did patients with fewer than two factors (96.8% and 72.9%, respectively; p < 0.0001). Conclusions: The prognostic factors associated with supraclavicular node recurrence were lymphovascular invasion, extracapsular extension, and the number and level of involved axillary nodes. Patients with two or more prognostic factors might benefit from SCRT.« less

Weighted compactness function based label propagation algorithm for community detection

NASA Astrophysics Data System (ADS)

Zhang, Weitong; Zhang, Rui; Shang, Ronghua; Jiao, Licheng

2018-02-01

Community detection in complex networks, is to detect the community structure with the internal structure relatively compact and the external structure relatively sparse, according to the topological relationship among nodes in the network. In this paper, we propose a compactness function which combines the weight of nodes, and use it as the objective function to carry out the node label propagation. Firstly, according to the node degree, we find the sets of core nodes which have great influence on the network. The more the connections between the core nodes and the other nodes are, the larger the amount of the information these kernel nodes receive and transform. Then, according to the similarity of the nodes between the core nodes sets and the nodes degree, we assign weights to the nodes in the network. So the label of the nodes with great influence will be the priority in the label propagation process, which effectively improves the accuracy of the label propagation. The compactness function between nodes and communities in this paper is based on the nodes influence. It combines the connections between nodes and communities with the degree of the node belongs to its neighbor communities based on calculating the node weight. The function effectively uses the information of nodes and connections in the network. The experimental results show that the proposed algorithm can achieve good results in the artificial network and large-scale real networks compared with the 8 contrast algorithms.

System for conversion between the boundary representation model and a constructive solid geometry model of an object

DOEpatents

Christensen, N.C.; Emery, J.D.; Smith, M.L.

1985-04-29

A system converts from the boundary representation of an object to the constructive solid geometry representation thereof. The system converts the boundary representation of the object into elemental atomic geometrical units or I-bodies which are in the shape of stock primitives or regularized intersections of stock primitives. These elemental atomic geometrical units are then represented in symbolic form. The symbolic representations of the elemental atomic geometrical units are then assembled heuristically to form a constructive solid geometry representation of the object usable for manufacturing thereof. Artificial intelligence is used to determine the best constructive solid geometry representation from the boundary representation of the object. Heuristic criteria are adapted to the manufacturing environment for which the device is to be utilized. The surface finish, tolerance, and other information associated with each surface of the boundary representation of the object are mapped onto the constructive solid geometry representation of the object to produce an enhanced solid geometry representation, particularly useful for computer-aided manufacture of the object. 19 figs.

KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi (left), with the National Space Development Agency of Japan (NASDA), points to data on the console during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM) in the Space Station Processing Facility. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 provides attach locations for the Japanese laboratory, as well as European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. Installation of the module will complete the U.S. Core of the ISS.

NASA Image and Video Library

2003-09-03

KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi (left), with the National Space Development Agency of Japan (NASDA), points to data on the console during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM) in the Space Station Processing Facility. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 provides attach locations for the Japanese laboratory, as well as European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. Installation of the module will complete the U.S. Core of the ISS.

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, astronaut Soichi Noguchi (right), with the National Space Development Agency of Japan (NASDA), stands inside the Japanese Experiment Module (JEM) that is undergoing a Multi-Element Integrated Test (MEIT) with the U.S. Node 2. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 provides attach locations for the Japanese laboratory, as well as European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. Installation of the module will complete the U.S. Core of the ISS.

NASA Image and Video Library

2003-09-03

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, astronaut Soichi Noguchi (right), with the National Space Development Agency of Japan (NASDA), stands inside the Japanese Experiment Module (JEM) that is undergoing a Multi-Element Integrated Test (MEIT) with the U.S. Node 2. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 provides attach locations for the Japanese laboratory, as well as European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. Installation of the module will complete the U.S. Core of the ISS.

KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi (left), with the National Space Development Agency of Japan (NASDA), works at a console during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM) in the Space Station Processing Facility. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 provides attach locations for the Japanese laboratory, as well as European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. Installation of the module will complete the U.S. Core of the ISS.

NASA Image and Video Library

2003-09-03

KENNEDY SPACE CENTER, FLA. - Astronaut Soichi Noguchi (left), with the National Space Development Agency of Japan (NASDA), works at a console during a Multi-Element Integrated Test (MEIT) of the U.S. Node 2 and the Japanese Experiment Module (JEM) in the Space Station Processing Facility. The JEM, developed by NASDA, is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. Noguchi is assigned to mission STS-114 as a mission specialist. Node 2 provides attach locations for the Japanese laboratory, as well as European laboratory, the Centrifuge Accommodation Module and, eventually, Multipurpose Logistics Modules. Installation of the module will complete the U.S. Core of the ISS.

Corner-corrected diagonal-norm summation-by-parts operators for the first derivative with increased order of accuracy

NASA Astrophysics Data System (ADS)

Del Rey Fernández, David C.; Boom, Pieter D.; Zingg, David W.

2017-02-01

Combined with simultaneous approximation terms, summation-by-parts (SBP) operators offer a versatile and efficient methodology that leads to consistent, conservative, and provably stable discretizations. However, diagonal-norm operators with a repeating interior-point operator that have thus far been constructed suffer from a loss of accuracy. While on the interior, these operators are of degree 2p, at a number of nodes near the boundaries, they are of degree p, and therefore of global degree p - meaning the highest degree monomial for which the operators are exact at all nodes. This implies that for hyperbolic problems and operators of degree greater than unity they lead to solutions with a global order of accuracy lower than the degree of the interior-point operator. In this paper, we develop a procedure to construct diagonal-norm first-derivative SBP operators that are of degree 2p at all nodes and therefore can lead to solutions of hyperbolic problems of order 2 p + 1. This is accomplished by adding nonzero entries in the upper-right and lower-left corners of SBP operator matrices with a repeating interior-point operator. This modification necessitates treating these new operators as elements, where mesh refinement is accomplished by increasing the number of elements in the mesh rather than increasing the number of nodes. The significant improvements in accuracy of this new family, for the same repeating interior-point operator, are demonstrated in the context of the linear convection equation.

Three-Dimensional Computer Model of the Right Atrium Including the Sinoatrial and Atrioventricular Nodes Predicts Classical Nodal Behaviours

PubMed Central

Li, Jue; Inada, Shin; Schneider, Jurgen E.; Zhang, Henggui; Dobrzynski, Halina; Boyett, Mark R.

2014-01-01

The aim of the study was to develop a three-dimensional (3D) anatomically-detailed model of the rabbit right atrium containing the sinoatrial and atrioventricular nodes to study the electrophysiology of the nodes. A model was generated based on 3D images of a rabbit heart (atria and part of ventricles), obtained using high-resolution magnetic resonance imaging. Segmentation was carried out semi-manually. A 3D right atrium array model (∼3.16 million elements), including eighteen objects, was constructed. For description of cellular electrophysiology, the Rogers-modified FitzHugh-Nagumo model was further modified to allow control of the major characteristics of the action potential with relatively low computational resource requirements. Model parameters were chosen to simulate the action potentials in the sinoatrial node, atrial muscle, inferior nodal extension and penetrating bundle. The block zone was simulated as passive tissue. The sinoatrial node, crista terminalis, main branch and roof bundle were considered as anisotropic. We have simulated normal and abnormal electrophysiology of the two nodes. In accordance with experimental findings: (i) during sinus rhythm, conduction occurs down the interatrial septum and into the atrioventricular node via the fast pathway (conduction down the crista terminalis and into the atrioventricular node via the slow pathway is slower); (ii) during atrial fibrillation, the sinoatrial node is protected from overdrive by its long refractory period; and (iii) during atrial fibrillation, the atrioventricular node reduces the frequency of action potentials reaching the ventricles. The model is able to simulate ventricular echo beats. In summary, a 3D anatomical model of the right atrium containing the cardiac conduction system is able to simulate a wide range of classical nodal behaviours. PMID:25380074

Model of myosin node aggregation into a contractile ring: the effect of local alignment

NASA Astrophysics Data System (ADS)

Ojkic, Nikola; Wu, Jian-Qiu; Vavylonis, Dimitrios

2011-09-01

Actomyosin bundles frequently form through aggregation of membrane-bound myosin clusters. One such example is the formation of the contractile ring in fission yeast from a broad band of cortical nodes. Nodes are macromolecular complexes containing several dozens of myosin-II molecules and a few formin dimers. The condensation of a broad band of nodes into the contractile ring has been previously described by a search, capture, pull and release (SCPR) model. In SCPR, a random search process mediated by actin filaments nucleated by formins leads to transient actomyosin connections among nodes that pull one another into a ring. The SCPR model reproduces the transport of nodes over long distances and predicts observed clump-formation instabilities in mutants. However, the model does not generate transient linear elements and meshwork structures as observed in some wild-type and mutant cells during ring assembly. As a minimal model of node alignment, we added short-range aligning forces to the SCPR model representing currently unresolved mechanisms that may involve structural components, cross-linking and bundling proteins. We studied the effect of the local node alignment mechanism on ring formation numerically. We varied the new parameters and found viable rings for a realistic range of values. Morphologically, transient structures that form during ring assembly resemble those observed in experiments with wild-type and cdc25-22 cells. Our work supports a hierarchical process of ring self-organization involving components drawn together from distant parts of the cell followed by progressive stabilization.

Study of some characteristic Mediterranean vegetation species best suited for renaturalization of terminal-phase municipal solid waste (MSW) landfills in Puglia (Southern Italy)

NASA Astrophysics Data System (ADS)

De Mei, Massimiliano; Di Mauro, Mariaida

2006-07-01

Natural recovery of worked-out or closed municipal solid waste (MSW) landfills is a current topic, but knowledge about the adaptability of Mediterranean vegetation species to such stressful conditions is still quite poor. Autochthonous plants were selected to withstand the stresses such as hot climate and drought typical of Mediterranean areas; this characteristic potentially allows the plants an easier, efficient adaptation. Our aim was to provide information in order to obtain an adequate quality of environmental renewal of a landfill and a reduced management cost while ensuring rehabilitation to an acceptable naturalistic state. The investigation lasted 3 years; some Mediterranean scrub native plant species were selected and monitored in their morphological (total and relative height, basal diameter, number of inter-nodes) and physiological (photosynthetic rate and water potential) activity. In order to test dependence on CO 2 concentration, different meteorological parameters were also monitored. Ceratonia siliqua, Phillyrea latifolia, Olea europaea and Quercus ilex showed considerable adaptability, reacting positively to every improvement in environmental conditions, particularly those of a meteorological nature. Survival and growth was satisfactory in Hedysarum coronarium, Medicago sativa, Lotus corniculatus, Rosmarinus officinalis, Myrtus communis and Viburnum tinus. Fraxinus ornus and Acer campestre suffered stress during the summer dry period and recovered quickly when atmospheric conditions improved. A drop irrigation system to ensure a satisfactory soil moisture during summer dry periods was the fundamental element for survival.

Novel diagnostic procedure for determining metastasis to sentinel lymph nodes in breast cancer using a semi-dry dot-blot method.

PubMed

Otsubo, Ryota; Oikawa, Masahiro; Hirakawa, Hiroshi; Shibata, Kenichiro; Abe, Kuniko; Hayashi, Tomayoshi; Kinoshita, Naoe; Shigematsu, Kazuto; Hatachi, Toshiko; Yano, Hiroshi; Matsumoto, Megumi; Takagi, Katsunori; Tsuchiya, Tomoshi; Tomoshige, Koichi; Nakashima, Masahiro; Taniguchi, Hideki; Omagari, Takeyuki; Itoyanagi, Noriaki; Nagayasu, Takeshi

2014-02-15

We developed an easy, quick and cost-effective detection method for lymph node metastasis called the semi-dry dot-blot (SDB) method, which visualizes the presence of cancer cells with washing of sectioned lymph nodes by anti-pancytokeratin antibody, modifying dot-blot technology. We evaluated the validity and efficacy of the SDB method for the diagnosis of lymph node metastasis in a clinical setting (Trial 1). To evaluate the validity of the SDB method in clinical specimens, 180 dissected lymph nodes from 29 cases, including breast, gastric and colorectal cancer, were examined. Each lymph node was sliced at the maximum diameter and the sensitivity, specificity and accuracy of the SDB method were determined and compared with the final pathology report. Metastasis was detected in 32 lymph nodes (17.8%), and the sensitivity, specificity and accuracy of the SDB method were 100, 98.0 and 98.3%, respectively (Trial 2). To evaluate the efficacy of the SDB method in sentinel lymph node (SLN) biopsy, 174 SLNs from 100 cases of clinically node-negative breast cancer were analyzed. Each SLN was longitudinally sliced at 2-mm intervals and the sensitivity, specificity, accuracy and time required for the SDB method were determined and compared with the intraoperative pathology report. Metastasis was detected in 15 SLNs (8.6%), and the sensitivity, specificity, accuracy and mean required time of the SDB method were 93.3, 96.9, 96.6 and 43.3 min, respectively. The SDB method is a novel and reliable modality for the intraoperative diagnosis of SLN metastasis. © 2013 UICC.

Mast cells mediate the immune suppression induced by dermal exposure to JP-8 jet fuel.

PubMed

Limón-Flores, Alberto Y; Chacón-Salinas, Rommel; Ramos, Gerardo; Ullrich, Stephen E

2009-11-01

Applying jet propulsion-8 (JP-8) jet fuel to the skin of mice induces immune suppression. Applying JP-8 to the skin of mice suppresses T-cell-mediated immune reactions including, contact hypersensitivity (CHS) delayed-type hypersensitivity and T-cell proliferation. Because dermal mast cells play an important immune regulatory role in vivo, we tested the hypothesis that mast cells mediate jet fuel-induced immune suppression. When we applied JP-8 to the skin of mast cell deficient mice CHS was not suppressed. Reconstituting mast cell deficient mice with wild-type bone marrow derived mast cells (mast cell "knock-in mice") restored JP-8-induced immune suppression. When, however, mast cells from prostaglandin E(2) (PGE(2))-deficient mice were used, the ability of JP-8 to suppress CHS was not restored, indicating that mast cell-derived PGE(2) was activating immune suppression. Examining the density of mast cells in the skin and lymph nodes of JP-8-treated mice indicated that jet fuel treatment caused an initial increase in mast cell density in the skin, followed by increased numbers of mast cells in the subcutaneous space and then in draining lymph nodes. Applying JP-8 to the skin increased mast cell expression of CXCR4, and increased the expression of CXCL12 by draining lymph node cells. Because CXCL12 is a chemoattractant for CXCR4+ mast cells, we treated JP-8-treated mice with AMD3100, a CXCR4 antagonist. AMD3100 blocked the mobilization of mast cells to the draining lymph node and inhibited JP-8-induced immune suppression. Our findings demonstrate the importance of mast cells in mediating jet fuel-induced immune suppression.

Mast Cells Mediate the Immune Suppression Induced by Dermal Exposure to JP-8 Jet Fuel

PubMed Central

Limón-Flores, Alberto Y.; Chacón-Salinas, Rommel; Ramos, Gerardo; Ullrich, Stephen E.

2009-01-01

Applying jet propulsion-8 (JP-8) jet fuel to the skin of mice induces immune suppression. Applying JP-8 to the skin of mice suppresses T-cell–mediated immune reactions including, contact hypersensitivity (CHS) delayed-type hypersensitivity and T-cell proliferation. Because dermal mast cells play an important immune regulatory role in vivo, we tested the hypothesis that mast cells mediate jet fuel–induced immune suppression. When we applied JP-8 to the skin of mast cell deficient mice CHS was not suppressed. Reconstituting mast cell deficient mice with wild-type bone marrow derived mast cells (mast cell “knock-in mice”) restored JP-8–induced immune suppression. When, however, mast cells from prostaglandin E2 (PGE2)–deficient mice were used, the ability of JP-8 to suppress CHS was not restored, indicating that mast cell–derived PGE2 was activating immune suppression. Examining the density of mast cells in the skin and lymph nodes of JP-8-treated mice indicated that jet fuel treatment caused an initial increase in mast cell density in the skin, followed by increased numbers of mast cells in the subcutaneous space and then in draining lymph nodes. Applying JP-8 to the skin increased mast cell expression of CXCR4, and increased the expression of CXCL12 by draining lymph node cells. Because CXCL12 is a chemoattractant for CXCR4+ mast cells, we treated JP-8-treated mice with AMD3100, a CXCR4 antagonist. AMD3100 blocked the mobilization of mast cells to the draining lymph node and inhibited JP-8–induced immune suppression. Our findings demonstrate the importance of mast cells in mediating jet fuel–induced immune suppression. PMID:19726579

Study of Solid State Drives performance in PROOF distributed analysis system

NASA Astrophysics Data System (ADS)

Panitkin, S. Y.; Ernst, M.; Petkus, R.; Rind, O.; Wenaus, T.

2010-04-01

Solid State Drives (SSD) is a promising storage technology for High Energy Physics parallel analysis farms. Its combination of low random access time and relatively high read speed is very well suited for situations where multiple jobs concurrently access data located on the same drive. It also has lower energy consumption and higher vibration tolerance than Hard Disk Drive (HDD) which makes it an attractive choice in many applications raging from personal laptops to large analysis farms. The Parallel ROOT Facility - PROOF is a distributed analysis system which allows to exploit inherent event level parallelism of high energy physics data. PROOF is especially efficient together with distributed local storage systems like Xrootd, when data are distributed over computing nodes. In such an architecture the local disk subsystem I/O performance becomes a critical factor, especially when computing nodes use multi-core CPUs. We will discuss our experience with SSDs in PROOF environment. We will compare performance of HDD with SSD in I/O intensive analysis scenarios. In particular we will discuss PROOF system performance scaling with a number of simultaneously running analysis jobs.

Two-photon interference at telecom wavelengths for time-bin-encoded single photons from quantum-dot spin qubits

PubMed Central

Yu, Leo; Natarajan, Chandra M.; Horikiri, Tomoyuki; Langrock, Carsten; Pelc, Jason S.; Tanner, Michael G.; Abe, Eisuke; Maier, Sebastian; Schneider, Christian; Höfling, Sven; Kamp, Martin; Hadfield, Robert H.; Fejer, Martin M.; Yamamoto, Yoshihisa

2015-01-01

Practical quantum communication between remote quantum memories rely on single photons at telecom wavelengths. Although spin-photon entanglement has been demonstrated in atomic and solid-state qubit systems, the produced single photons at short wavelengths and with polarization encoding are not suitable for long-distance communication, because they suffer from high propagation loss and depolarization in optical fibres. Establishing entanglement between remote quantum nodes would further require the photons generated from separate nodes to be indistinguishable. Here, we report the observation of correlations between a quantum-dot spin and a telecom single photon across a 2-km fibre channel based on time-bin encoding and background-free frequency downconversion. The downconverted photon at telecom wavelengths exhibits two-photon interference with another photon from an independent source, achieving a mean wavepacket overlap of greater than 0.89 despite their original wavelength mismatch (900 and 911 nm). The quantum-networking operations that we demonstrate will enable practical communication between solid-state spin qubits across long distances. PMID:26597223

Enabling Tussle-Agile Inter-networking Architectures by Underlay Virtualisation

NASA Astrophysics Data System (ADS)

Dianati, Mehrdad; Tafazolli, Rahim; Moessner, Klaus

In this paper, we propose an underlay inter-network virtualisation framework in order to enable tussle-agile flexible networking over the existing inter-network infrastructures. The functionalities that inter-networking elements (transit nodes, access networks, etc.) need to support in order to enable virtualisation are discussed. We propose the base architectures of each the abstract elements to support the required inter-network virtualisation functionalities.

Curvature estimation for multilayer hinged structures with initial strains

NASA Astrophysics Data System (ADS)

Nikishkov, G. P.

2003-10-01

Closed-form estimate of curvature for hinged multilayer structures with initial strains is developed. The finite element method is used for modeling of self-positioning microstructures. The geometrically nonlinear problem with large rotations and large displacements is solved using step procedure with node coordinate update. Finite element results for curvature of the hinged micromirror with variable width is compared to closed-form estimates.