Effect of Six Days of Staging on Physiologic Adjustments and Acute Mountain Sickness During Ascent to 4300 Meters

DTIC Science & Technology

2009-01-01

respiratory alkalosis due to hyperventilation that was partially compensated for by increased excretion of HCO3 to maintain a normal pH following...carbon dioxide; RER, respiratory exchange quotient; Sao2, arterial oxygen saturation; Paco2, partial pressure of capillary-arterialized carbon dioxide...dioxide production; E=O2, ventilatory equivalent for oxygen; E=CO2, ventilatory equivalent for carbon dioxide; RER, respiratory exchange quotient

Dynamic Characteristics of Micro-Beams Considering the Effect of Flexible Supports

PubMed Central

Zhong, Zuo-Yang; Zhang, Wen-Ming; Meng, Guang

2013-01-01

Normally, the boundaries are assumed to allow small deflections and moments for MEMS beams with flexible supports. The non-ideal boundary conditions have a significant effect on the qualitative dynamical behavior. In this paper, by employing the principle of energy equivalence, rigorous theoretical solutions of the tangential and rotational equivalent stiffness are derived based on the Boussinesq's and Cerruti's displacement equations. The non-dimensional differential partial equation of the motion, as well as coupled boundary conditions, are solved analytically using the method of multiple time scales. The closed-form solution provides a direct insight into the relationship between the boundary conditions and vibration characteristics of the dynamic system, in which resonance frequencies increase with the nonlinear mechanical spring effect but decrease with the effect of flexible supports. The obtained results of frequencies and mode shapes are compared with the cases of ideal boundary conditions, and the differences between them are contrasted on frequency response curves. The influences of the support material property on the equivalent stiffness and resonance frequency shift are also discussed. It is demonstrated that the proposed model with the flexible supports boundary conditions has significant effect on the rigorous quantitative dynamical analysis of the MEMS beams. Moreover, the proposed analytical solutions are in good agreement with those obtained from finite element analyses.

Critical study of higher order numerical methods for solving the boundary-layer equations

NASA Technical Reports Server (NTRS)

Wornom, S. F.

1978-01-01

A fourth order box method is presented for calculating numerical solutions to parabolic, partial differential equations in two variables or ordinary differential equations. The method, which is the natural extension of the second order box scheme to fourth order, was demonstrated with application to the incompressible, laminar and turbulent, boundary layer equations. The efficiency of the present method is compared with two point and three point higher order methods, namely, the Keller box scheme with Richardson extrapolation, the method of deferred corrections, a three point spline method, and a modified finite element method. For equivalent accuracy, numerical results show the present method to be more efficient than higher order methods for both laminar and turbulent flows.

Mapping of the Resistance of a Superconducting Transition Edge Sensor as a Function of Temperature, Current, and Applied Magnetic Field

NASA Technical Reports Server (NTRS)

Zhang, Shou; Eckart, Megan E.; Jaeckel, Felix; Kripps, Kari L.; McCammon, Dan; Zhou, Yu; Morgan, Kelsey M.

2017-01-01

We have measured the resistance R (T, I, B(sub ext) of a superconducting transition edge sensor over the entire transition region on a fine scale, producing a four-dimensional map of the resistance surface. The dimensionless temperature and current sensitivities (alpha equivalence partial derivative log R/partial derivative log T|(sub I) and beta equivalence partial derivative log R/partial derivative log I|(sub T) of the TES resistance have been determined at each point. alpha and beta are closely related to the sensor performance, but show a great deal of complex, large amplitude fine structure over large portions of the surface that is sensitive to the applied magnetic field. We discuss the relation of this structure to the presence of Josephson weak link fringes.

Calculation of reaction forces in the boiler supports using the method of equivalent stiffness of membrane wall.

PubMed

Sertić, Josip; Kozak, Dražan; Samardžić, Ivan

2014-01-01

The values of reaction forces in the boiler supports are the basis for the dimensioning of bearing steel structure of steam boiler. In this paper, the application of the method of equivalent stiffness of membrane wall is proposed for the calculation of reaction forces. The method of equalizing displacement, as the method of homogenization of membrane wall stiffness, was applied. On the example of "Milano" boiler, using the finite element method, the calculation of reactions in the supports for the real geometry discretized by the shell finite element was made. The second calculation was performed with the assumption of ideal stiffness of membrane walls and the third using the method of equivalent stiffness of membrane wall. In the third case, the membrane walls are approximated by the equivalent orthotropic plate. The approximation of membrane wall stiffness is achieved using the elasticity matrix of equivalent orthotropic plate at the level of finite element. The obtained results were compared, and the advantages of using the method of equivalent stiffness of membrane wall for the calculation of reactions in the boiler supports were emphasized.

Equivalent Circuit Parameter Calculation of Interior Permanent Magnet Motor Involving Iron Loss Resistance Using Finite Element Method

NASA Astrophysics Data System (ADS)

Yamazaki, Katsumi

In this paper, we propose a method to calculate the equivalent circuit parameters of interior permanent magnet motors including iron loss resistance using the finite element method. First, the finite element analysis considering harmonics and magnetic saturation is carried out to obtain time variations of magnetic fields in the stator and the rotor core. Second, the iron losses of the stator and the rotor are calculated from the results of the finite element analysis with the considerations of harmonic eddy current losses and the minor hysteresis losses of the core. As a result, we obtain the equivalent circuit parameters i.e. the d-q axis inductance and the iron loss resistance as functions of operating condition of the motor. The proposed method is applied to an interior permanent magnet motor to calculate the characteristics based on the equivalent circuit obtained by the proposed method. The calculated results are compared with the experimental results to verify the accuracy.

31 CFR 100.11 - Exchange of bent and partial coins.

Code of Federal Regulations, 2013 CFR

2013-07-01

... partial coins shall be presented separately by denomination category in lots of at least one pound for... redeemed at the face value equivalent of copper one cent coins. (c) Redemption site. Bent and partial coins will be redeemed only at the United States Mint, P.O. Box 400, Philadelphia, PA 19105. Coins are...

Causal dissipation for the relativistic dynamics of ideal gases

NASA Astrophysics Data System (ADS)

Freistühler, Heinrich; Temple, Blake

2017-05-01

We derive a general class of relativistic dissipation tensors by requiring that, combined with the relativistic Euler equations, they form a second-order system of partial differential equations which is symmetric hyperbolic in a second-order sense when written in the natural Godunov variables that make the Euler equations symmetric hyperbolic in the first-order sense. We show that this class contains a unique element representing a causal formulation of relativistic dissipative fluid dynamics which (i) is equivalent to the classical descriptions by Eckart and Landau to first order in the coefficients of viscosity and heat conduction and (ii) has its signal speeds bounded sharply by the speed of light. Based on these properties, we propose this system as a natural candidate for the relativistic counterpart of the classical Navier-Stokes equations.

Causal dissipation for the relativistic dynamics of ideal gases

PubMed Central

2017-01-01

We derive a general class of relativistic dissipation tensors by requiring that, combined with the relativistic Euler equations, they form a second-order system of partial differential equations which is symmetric hyperbolic in a second-order sense when written in the natural Godunov variables that make the Euler equations symmetric hyperbolic in the first-order sense. We show that this class contains a unique element representing a causal formulation of relativistic dissipative fluid dynamics which (i) is equivalent to the classical descriptions by Eckart and Landau to first order in the coefficients of viscosity and heat conduction and (ii) has its signal speeds bounded sharply by the speed of light. Based on these properties, we propose this system as a natural candidate for the relativistic counterpart of the classical Navier–Stokes equations. PMID:28588397

Causal dissipation for the relativistic dynamics of ideal gases.

PubMed

Freistühler, Heinrich; Temple, Blake

2017-05-01

We derive a general class of relativistic dissipation tensors by requiring that, combined with the relativistic Euler equations, they form a second-order system of partial differential equations which is symmetric hyperbolic in a second-order sense when written in the natural Godunov variables that make the Euler equations symmetric hyperbolic in the first-order sense. We show that this class contains a unique element representing a causal formulation of relativistic dissipative fluid dynamics which (i) is equivalent to the classical descriptions by Eckart and Landau to first order in the coefficients of viscosity and heat conduction and (ii) has its signal speeds bounded sharply by the speed of light. Based on these properties, we propose this system as a natural candidate for the relativistic counterpart of the classical Navier-Stokes equations.

Viscoelastic flow modeling in the extrusion of a dough-like fluid

NASA Technical Reports Server (NTRS)

Dhanasekharan, M.; Kokini, J. L.; Janes, H. W. (Principal Investigator)

2000-01-01

This work attempts to investigate the effect of viscoelasticity and three-dimensional geometry in screw channels. The Phan-Thien Tanner (PTT) constitutive equation with simplified model parameters was solved in conjunction with the flow equations. Polyflow, a commercially available finite element code was used to solve the resulting nonlinear partial differential equations. The PTT model predicted one log scale lower pressure buildup compared to the equivalent Newtonian results. However, the velocity profile did not show significant changes for the chosen PTT model parameters. Past Researchers neglected viscoelastic effects and also the three dimensional nature of the flow in extruder channels. The results of this paper provide a starting point for further simulations using more realistic model parameters, which may enable the food engineer to more accurately scale-up and design extrusion processes.

Comparison of Nonlinear Random Response Using Equivalent Linearization and Numerical Simulation

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Muravyov, Alexander A.

2000-01-01

A recently developed finite-element-based equivalent linearization approach for the analysis of random vibrations of geometrically nonlinear multiple degree-of-freedom structures is validated. The validation is based on comparisons with results from a finite element based numerical simulation analysis using a numerical integration technique in physical coordinates. In particular, results for the case of a clamped-clamped beam are considered for an extensive load range to establish the limits of validity of the equivalent linearization approach.

Calculation of Reaction Forces in the Boiler Supports Using the Method of Equivalent Stiffness of Membrane Wall

PubMed Central

Sertić, Josip; Kozak, Dražan; Samardžić, Ivan

2014-01-01

The values of reaction forces in the boiler supports are the basis for the dimensioning of bearing steel structure of steam boiler. In this paper, the application of the method of equivalent stiffness of membrane wall is proposed for the calculation of reaction forces. The method of equalizing displacement, as the method of homogenization of membrane wall stiffness, was applied. On the example of “Milano” boiler, using the finite element method, the calculation of reactions in the supports for the real geometry discretized by the shell finite element was made. The second calculation was performed with the assumption of ideal stiffness of membrane walls and the third using the method of equivalent stiffness of membrane wall. In the third case, the membrane walls are approximated by the equivalent orthotropic plate. The approximation of membrane wall stiffness is achieved using the elasticity matrix of equivalent orthotropic plate at the level of finite element. The obtained results were compared, and the advantages of using the method of equivalent stiffness of membrane wall for the calculation of reactions in the boiler supports were emphasized. PMID:24959612

Verification of finite element analysis of fixed partial denture with in vitro electronic strain measurement.

PubMed

Wang, Gaoqi; Zhang, Song; Bian, Cuirong; Kong, Hui

2016-01-01

The purpose of the study was to verify the finite element analysis model of three-unite fixed partial denture with in vitro electronic strain analysis and analyze clinical situation with the verified model. First, strain gauges were attached to the critical areas of a three-unit fixed partial denture. Strain values were measured under 300 N load perpendicular to the occlusal plane. Secondly, a three-dimensional finite element model in accordance with the electronic strain analysis experiment was constructed from the scanning data. And the strain values obtained by finite element analysis and in vitro measurements were compared. Finally, the clinical destruction of the fixed partial denture was evaluated with the verified finite element analysis model. There was a mutual agreement and consistency between the finite element analysis results and experimental data. The finite element analysis revealed that failure will occur in the veneer layer on buccal surface of the connector under occlusal force of 570 N. The results indicate that the electronic strain analysis is an appropriate and cost saving method to verify the finite element model. The veneer layer on buccal surface of the connector is the weakest area in the fixed partial denture. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Transtendon, Double-Row, Transosseous-Equivalent Arthroscopic Repair of Partial-Thickness, Articular-Surface Rotator Cuff Tears

PubMed Central

Dilisio, Matthew F.; Miller, Lindsay R.; Higgins, Laurence D.

2014-01-01

Arthroscopic transtendinous techniques for the arthroscopic repair of partial-thickness, articular-surface rotator cuff tears offer the advantage of minimizing the disruption of the patient's remaining rotator cuff tendon fibers. In addition, double-row fixation of full-thickness rotator cuff tears has shown biomechanical advantages. We present a novel method combining these 2 techniques for transtendon, double-row, transosseous-equivalent arthroscopic repair of partial-thickness, articular-surface rotator cuff tears. Direct visualization of the reduction of the retracted articular tendon layer to its insertion on the greater tuberosity is the key to the procedure. Linking the medial-row anchors and using a double-row construct provide a stable repair that allows early shoulder motion to minimize the risk of postoperative stiffness. PMID:25473606

Transtendon, double-row, transosseous-equivalent arthroscopic repair of partial-thickness, articular-surface rotator cuff tears.

PubMed

Dilisio, Matthew F; Miller, Lindsay R; Higgins, Laurence D

2014-10-01

Arthroscopic transtendinous techniques for the arthroscopic repair of partial-thickness, articular-surface rotator cuff tears offer the advantage of minimizing the disruption of the patient's remaining rotator cuff tendon fibers. In addition, double-row fixation of full-thickness rotator cuff tears has shown biomechanical advantages. We present a novel method combining these 2 techniques for transtendon, double-row, transosseous-equivalent arthroscopic repair of partial-thickness, articular-surface rotator cuff tears. Direct visualization of the reduction of the retracted articular tendon layer to its insertion on the greater tuberosity is the key to the procedure. Linking the medial-row anchors and using a double-row construct provide a stable repair that allows early shoulder motion to minimize the risk of postoperative stiffness.

Gauging Spatial Symmetries and the Classification of Topological Crystalline Phases

NASA Astrophysics Data System (ADS)

Thorngren, Ryan; Else, Dominic V.

2018-01-01

We put the theory of interacting topological crystalline phases on a systematic footing. These are topological phases protected by space-group symmetries. Our central tool is an elucidation of what it means to "gauge" such symmetries. We introduce the notion of a crystalline topological liquid and argue that most (and perhaps all) phases of interest are likely to satisfy this criterion. We prove a crystalline equivalence principle, which states that in Euclidean space, crystalline topological liquids with symmetry group G are in one-to-one correspondence with topological phases protected by the same symmetry G , but acting internally, where if an element of G is orientation reversing, it is realized as an antiunitary symmetry in the internal symmetry group. As an example, we explicitly compute, using group cohomology, a partial classification of bosonic symmetry-protected topological phases protected by crystalline symmetries in (3 +1 ) dimensions for 227 of the 230 space groups. For the 65 space groups not containing orientation-reversing elements (Sohncke groups), there are no cobordism invariants that may contribute phases beyond group cohomology, so we conjecture that our classification is complete.

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.

A formal and data-based comparison of measures of motor-equivalent covariation.

PubMed

Verrel, Julius

2011-09-15

Different analysis methods have been developed for assessing motor-equivalent organization of movement variability. In the uncontrolled manifold (UCM) method, the structure of variability is analyzed by comparing goal-equivalent and non-goal-equivalent variability components at the level of elemental variables (e.g., joint angles). In contrast, in the covariation by randomization (CR) approach, motor-equivalent organization is assessed by comparing variability at the task level between empirical and decorrelated surrogate data. UCM effects can be due to both covariation among elemental variables and selective channeling of variability to elemental variables with low task sensitivity ("individual variation"), suggesting a link between the UCM and CR method. However, the precise relationship between the notion of covariation in the two approaches has not been analyzed in detail yet. Analysis of empirical and simulated data from a study on manual pointing shows that in general the two approaches are not equivalent, but the respective covariation measures are highly correlated (ρ > 0.7) for two proposed definitions of covariation in the UCM context. For one-dimensional task spaces, a formal comparison is possible and in fact the two notions of covariation are equivalent. In situations in which individual variation does not contribute to UCM effects, for which necessary and sufficient conditions are derived, this entails the equivalence of the UCM and CR analysis. Implications for the interpretation of UCM effects are discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

Method for measuring dose-equivalent in a neutron flux with an unknown energy spectra and means for carrying out that method

DOEpatents

Distenfeld, Carl H.

1978-01-01

A method for measuring the dose-equivalent for exposure to an unknown and/or time varing neutron flux which comprises simultaneously exposing a plurality of neutron detecting elements of different types to a neutron flux and combining the measured responses of the various detecting elements by means of a function, whose value is an approximate measure of the dose-equivalent, which is substantially independent of the energy spectra of the flux. Also, a personnel neutron dosimeter, which is useful in carrying out the above method, comprising a plurality of various neutron detecting elements in a single housing suitable for personnel to wear while working in a radiation area.

Mechanical properties investigation on single-wall ZrO2 nanotubes: A finite element method with equivalent Poisson's ratio for chemical bonds

NASA Astrophysics Data System (ADS)

Yang, Xiao; Li, Huijian; Hu, Minzheng; Liu, Zeliang; Wärnå, John; Cao, Yuying; Ahuja, Rajeev; Luo, Wei

2018-04-01

A method to obtain the equivalent Poisson's ratio in chemical bonds as classical beams with finite element method was proposed from experimental data. The UFF (Universal Force Field) method was employed to calculate the elastic force constants of Zrsbnd O bonds. By applying the equivalent Poisson's ratio, the mechanical properties of single-wall ZrNTs (ZrO2 nanotubes) were investigated by finite element analysis. The nanotubes' Young's modulus (Y), Poisson's ratio (ν) of ZrNTs as function of diameters, length and chirality have been discussed, respectively. We found that the Young's modulus of single-wall ZrNTs is calculated to be between 350 and 420 GPa.

Optimization of Transmit Parameters in Cardiac Strain Imaging With Full and Partial Aperture Coherent Compounding.

PubMed

Sayseng, Vincent; Grondin, Julien; Konofagou, Elisa E

2018-05-01

Coherent compounding methods using the full or partial transmit aperture have been investigated as a possible means of increasing strain measurement accuracy in cardiac strain imaging; however, the optimal transmit parameters in either compounding approach have yet to be determined. The relationship between strain estimation accuracy and transmit parameters-specifically the subaperture, angular aperture, tilt angle, number of virtual sources, and frame rate-in partial aperture (subaperture compounding) and full aperture (steered compounding) fundamental mode cardiac imaging was thus investigated and compared. Field II simulation of a 3-D cylindrical annulus undergoing deformation and twist was developed to evaluate accuracy of 2-D strain estimation in cross-sectional views. The tradeoff between frame rate and number of virtual sources was then investigated via transthoracic imaging in the parasternal short-axis view of five healthy human subjects, using the strain filter to quantify estimation precision. Finally, the optimized subaperture compounding sequence (25-element subperture, 90° angular aperture, 10 virtual sources, 300-Hz frame rate) was compared to the optimized steered compounding sequence (60° angular aperture, 15° tilt, 10 virtual sources, 300-Hz frame rate) via transthoracic imaging of five healthy subjects. Both approaches were determined to estimate cumulative radial strain with statistically equivalent precision (subaperture compounding E(SNRe %) = 3.56, and steered compounding E(SNRe %) = 4.26).

The influence of the alveolar ridge shape on the stress distribution in a free-end saddle removable partial denture supported by implant.

PubMed

Júnior, Manoel M; Anchieta, Rodolfo B; Rocha, Eduardo P; Pereira, João A; Archangelo, Carlos M; Freitas-Júnior, Amilcar C; Almeida, Erika O

2011-01-01

The alveolar ridge shape plays an important role in predicting the demand on the support tooth and alveolar bone in the removable partial denture (RPD) treatment. However, these data are unclear when the RPD is associated with implants. This study evaluated the influence of the alveolar ridge shape on the stress distribution of a free-end saddle RPD partially supported by implant using 2-dimensioanl finite element analysis (FEA). Four mathematical models (M) of a mandibular hemiarch simulating various alveolar ridge shapes (1-distal desceding, 2-concave, 3-horizontal and 4-distal ascending) were built. Tooth 33 was placed as the abutment. Two RPDs, one supported by tooth and fibromucosa (MB) and other one supported by tooth and implant (MC) were simulated. MA was the control (no RPD). The load (50N) were applied simultaneously on each cusp. Appropriate boundary conditions were assigned on the border of alveolar bone. Ansys 10.0 software was used to calculate the stress fields and the von Mises equivalent stress criteria (sigmavM) was applied to analyze the results. The distal ascending shape showed the highest sigmavM for cortical and medullar bone. The alveolar ridge shape had little effect on changing the sigmavM based on the same prosthesis, mainly around the abutment tooth.

77 FR 7523 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-13

... with 2 flow metering systems equipped with upgraded water absorbing filter elements. This AD was prompted by reports of partial blockage of a certain water absorbing filter element. We are issuing this AD to prevent partial blockage of a certain water absorbing filter element, which could lead to...

Imer-product array processor for retrieval of stored images represented by bipolar binary (+1,-1) pixels using partial input trinary pixels represented by (+1,-1)

NASA Technical Reports Server (NTRS)

Liu, Hua-Kuang (Inventor); Awwal, Abdul A. S. (Inventor); Karim, Mohammad A. (Inventor)

1993-01-01

An inner-product array processor is provided with thresholding of the inner product during each iteration to make more significant the inner product employed in estimating a vector to be used as the input vector for the next iteration. While stored vectors and estimated vectors are represented in bipolar binary (1,-1), only those elements of an initial partial input vector that are believed to be common with those of a stored vector are represented in bipolar binary; the remaining elements of a partial input vector are set to 0. This mode of representation, in which the known elements of a partial input vector are in bipolar binary form and the remaining elements are set equal to 0, is referred to as trinary representation. The initial inner products corresponding to the partial input vector will then be equal to the number of known elements. Inner-product thresholding is applied to accelerate convergence and to avoid convergence to a negative input product.

Equivalent air depth: fact or fiction.

PubMed

Berghage, T E; McCraken, T M

1979-12-01

In mixed-gas diving theory, the equivalent air depth (EAD) concept suggests that oxygen does not contribute to the total tissue gas tension and can therefore be disregarded in calculations of the decompression process. The validity of this assumption has been experimentally tested by exposing 365 rats to various partial pressures of oxygen for various lengths of time. If the EAD assumption is correct, under a constant exposure pressure each incremental change in the oxygen partial pressure would produce a corresponding incremental change in pressure reduction tolerance. Results of this study suggest that the EAD concept does not adequately describe the decompression advantages obtained from breathing elevated oxygen partial pressures. The authors suggest that the effects of breathing oxygen vary in a nonlinear fashion across the range from anoxia to oxygen toxicity, and that a simple inert gas replacement concept is no longer tenable.

Metrics for Labeled Markov Systems

NASA Technical Reports Server (NTRS)

Desharnais, Josee; Jagadeesan, Radha; Gupta, Vineet; Panangaden, Prakash

1999-01-01

Partial Labeled Markov Chains are simultaneously generalizations of process algebra and of traditional Markov chains. They provide a foundation for interacting discrete probabilistic systems, the interaction being synchronization on labels as in process algebra. Existing notions of process equivalence are too sensitive to the exact probabilities of various transitions. This paper addresses contextual reasoning principles for reasoning about more robust notions of "approximate" equivalence between concurrent interacting probabilistic systems. The present results indicate that:We develop a family of metrics between partial labeled Markov chains to formalize the notion of distance between processes. We show that processes at distance zero are bisimilar. We describe a decision procedure to compute the distance between two processes. We show that reasoning about approximate equivalence can be done compositionally by showing that process combinators do not increase distance. We introduce an asymptotic metric to capture asymptotic properties of Markov chains; and show that parallel composition does not increase asymptotic distance.

Improved Equivalent Linearization Implementations Using Nonlinear Stiffness Evaluation

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Muravyov, Alexander A.

2001-01-01

This report documents two new implementations of equivalent linearization for solving geometrically nonlinear random vibration problems of complicated structures. The implementations are given the acronym ELSTEP, for "Equivalent Linearization using a STiffness Evaluation Procedure." Both implementations of ELSTEP are fundamentally the same in that they use a novel nonlinear stiffness evaluation procedure to numerically compute otherwise inaccessible nonlinear stiffness terms from commercial finite element programs. The commercial finite element program MSC/NASTRAN (NASTRAN) was chosen as the core of ELSTEP. The FORTRAN implementation calculates the nonlinear stiffness terms and performs the equivalent linearization analysis outside of NASTRAN. The Direct Matrix Abstraction Program (DMAP) implementation performs these operations within NASTRAN. Both provide nearly identical results. Within each implementation, two error minimization approaches for the equivalent linearization procedure are available - force and strain energy error minimization. Sample results for a simply supported rectangular plate are included to illustrate the analysis procedure.

Evaluation of the equivalence ratio of the reacting mixture using intensity ratio of chemiluminescence in laminar partially premixed CH{sub 4}-air flames

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

Jeong, Yong Ki; Jeon, Chung Hwan; Chang, Young June

An experimental study was performed to investigate the effects of partially premixing, varying the equivalence ratios from 0.79 to 9.52, on OH*, CH* and C{sub 2}* in laminar partially premixed flames. The signals from the electronically excited states of OH*, CH* and C{sub 2}* were detected through interference filters using a photo multiplier tube, which were processed to the intensity ratios (C{sub 2}*/CH*, C{sub 2}*/OH* and CH*/OH*) to determine a correlation with the local equivalence ratios. Furthermore, the consistency between the results of the tomographic reconstruction; Abel inversion technique, image with CCD (Couple Charged Detector) camera and the local radicalmore » intensity with PMT was investigated. The results demonstrated that (1) the flames at F=<1.36 exhibited classical double flame structure, at F>=4.76, the flames exhibited non-premixed-like flame structure and the intermediate flames at 1.36

Theoretical prediction on corrugated sandwich panels under bending loads

NASA Astrophysics Data System (ADS)

Shu, Chengfu; Hou, Shujuan

2018-05-01

In this paper, an aluminum corrugated sandwich panel with triangular core under bending loads was investigated. Firstly, the equivalent material parameters of the triangular corrugated core layer, which could be considered as an orthotropic panel, were obtained by using Castigliano's theorem and equivalent homogeneous model. Secondly, contributions of the corrugated core layer and two face panels were both considered to compute the equivalent material parameters of the whole structure through the classical lamination theory, and these equivalent material parameters were compared with finite element analysis solutions. Then, based on the Mindlin orthotropic plate theory, this study obtain the closed-form solutions of the displacement for a corrugated sandwich panel under bending loads in specified boundary conditions, and parameters study and comparison by the finite element method were executed simultaneously.

Matrix multiplication operations with data pre-conditioning in a high performance computing architecture

DOEpatents

Eichenberger, Alexandre E; Gschwind, Michael K; Gunnels, John A

2013-11-05

Mechanisms for performing matrix multiplication operations with data pre-conditioning in a high performance computing architecture are provided. A vector load operation is performed to load a first vector operand of the matrix multiplication operation to a first target vector register. A load and splat operation is performed to load an element of a second vector operand and replicating the element to each of a plurality of elements of a second target vector register. A multiply add operation is performed on elements of the first target vector register and elements of the second target vector register to generate a partial product of the matrix multiplication operation. The partial product of the matrix multiplication operation is accumulated with other partial products of the matrix multiplication operation.

An electric-analog simulation of elliptic partial differential equations using finite element theory

USGS Publications Warehouse

Franke, O.L.; Pinder, G.F.; Patten, E.P.

1982-01-01

Elliptic partial differential equations can be solved using the Galerkin-finite element method to generate the approximating algebraic equations, and an electrical network to solve the resulting matrices. Some element configurations require the use of networks containing negative resistances which, while physically realizable, are more expensive and time-consuming to construct. ?? 1982.

Impedance characterization of AlGaN/GaN Schottky diodes with metal contacts

NASA Astrophysics Data System (ADS)

Donahue, M.; Lübbers, B.; Kittler, M.; Mai, P.; Schober, A.

2013-04-01

To obtain detailed information on structural and electrical properties of AlGaN/GaN Schottky diodes and to determine an appropriate equivalent circuit, impedance spectroscopy and impedance voltage profiling are employed over a frequency range of 1 MHz-1 Hz. In contrast to the commonly assumed parallel connection of capacitive and resistive elements, an equivalent circuit is derived from impedance spectra which utilizes the constant phase element and accounts for frequency dispersion and trap states. The trap density is estimated and is in good agreement with the literature values. The resulting reduced equivalent circuit consists of a capacitor and resistor connected in series.

78 FR 44052 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-23

... a regulatory distinction; and 4. Will not have a significant economic impact, positive or negative... events (LCF1) and partial low cycle fatigue events (LCF2) as those terms are defined in the... the full and partial low fatigue cycle events and record on the component card or equivalent record...

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

ICAN/PART: Particulate composite analyzer, user's manual and verification studies

NASA Technical Reports Server (NTRS)

Goldberg, Robert K.; Murthy, Pappu L. N.; Mital, Subodh K.

1996-01-01

A methodology for predicting the equivalent properties and constituent microstresses for particulate matrix composites, based on the micromechanics approach, is developed. These equations are integrated into a computer code developed to predict the equivalent properties and microstresses of fiber reinforced polymer matrix composites to form a new computer code, ICAN/PART. Details of the flowchart, input and output for ICAN/PART are described, along with examples of the input and output. Only the differences between ICAN/PART and the original ICAN code are described in detail, and the user is assumed to be familiar with the structure and usage of the original ICAN code. Detailed verification studies, utilizing dim dimensional finite element and boundary element analyses, are conducted in order to verify that the micromechanics methodology accurately models the mechanics of particulate matrix composites. ne equivalent properties computed by ICAN/PART fall within bounds established by the finite element and boundary element results. Furthermore, constituent microstresses computed by ICAN/PART agree in average sense with results computed using the finite element method. The verification studies indicate that the micromechanics programmed into ICAN/PART do indeed accurately model the mechanics of particulate matrix composites.

Finite element simulation and comparison of a shear strain and equivalent strain during ECAP and asymmetric rolling

NASA Astrophysics Data System (ADS)

Pesin, A.; Pustovoytov, D.; Shveyova, T.; Vafin, R.

2017-12-01

The level of a shear strain and equivalent strain plays a key role in terms of the possibility of using the asymmetric rolling process as a method of severe plastic deformation. Strain mode (pure shear or simple shear) can affect very strongly on the equivalent strain and the grain refinement of the material. This paper presents the results of FEM simulations and comparison of the equivalent strain in the aluminium alloy 5083 processed by a single-pass equal channel angular pressing (simple shear), symmetric rolling (pure shear) and asymmetric rolling (simultaneous pure and simple shear). The nonlinear effect of rolls speed ratio on the deformation characteristics during asymmetric rolling was found. Extremely high equivalent strain up to e=4.2 was reached during a single-pass asymmetric rolling. The influence of the shear strain on the level of equivalent strain is discussed. Finite element analysis of the deformation characteristics, presented in this study, can be used for optimization of the asymmetric rolling process as a method of severe plastic deformation.

Dynamic damping of vibrations of technical object with two degrees of freedom

NASA Astrophysics Data System (ADS)

Khomenko, A. P.; Eliseev, S. V.; Artyunin, A. I.

2017-10-01

Approach to the solution of problems of dynamic damping for the technical object with two degrees of freedom on the elastic supports is developed. Such tasks are typical for the dynamics of technological vibrating machines, machining machine tools and vehicles. The purpose of the study is to justify the possibility of obtaining regimes of simultaneous dynamic damping of oscillations in two coordinates. The achievement of the goal is based on the use of special devices for the transformation of motion, introduced parallel to the elastic element. The dynamic effect is provided by the possibility of changing the relationships between the reduced masses of devices for transforming motion. The method of structural mathematical modeling is used, in which the mechanical oscillatory system is compared, taking into account the principle of dynamic analogies, the dynamically equivalent structural diagram of the automatic control system. The concept of transfer functions of systems interpartial relations and generalized ideas about the partial frequencies and frequencies dynamic damping is applied. The concept of a frequency diagram that determines the mutual distribution of graphs of frequency characteristics in the interaction of the elements of the system is introduced.

Vertebrate LTR retrotransposons of the Tf1/sushi group.

PubMed

Butler, M; Goodwin, T; Simpson, M; Singh, M; Poulter, R

2001-03-01

LTR retrotransposons of the Tf1/sushi group from a diversity of vertebrates, including fish, amphibians, and mammals (humans, mice, and others), are described as full-length or partial elements. These elements are compared, and the mechanisms involved in self-priming of reverse transcriptase and programmed phase shifting are inferred. Evidence is presented that in mammals these elements are still transcriptionally active and are represented as proteins. This suggests that members of the Tf1/sushi group are present as functional elements (or incorporated as partial elements into host genes) in diverse vertebrate lineages.

Current matrix element in HAL QCD's wavefunction-equivalent potential method

NASA Astrophysics Data System (ADS)

Watanabe, Kai; Ishii, Noriyoshi

2018-04-01

We give a formula to calculate a matrix element of a conserved current in the effective quantum mechanics defined by the wavefunction-equivalent potentials proposed by the HAL QCD collaboration. As a first step, a non-relativistic field theory with two-channel coupling is considered as the original theory, with which a wavefunction-equivalent HAL QCD potential is obtained in a closed analytic form. The external field method is used to derive the formula by demanding that the result should agree with the original theory. With this formula, the matrix element is obtained by sandwiching the effective current operator between the left and right eigenfunctions of the effective Hamiltonian associated with the HAL QCD potential. In addition to the naive one-body current, the effective current operator contains an additional two-body term emerging from the degrees of freedom which has been integrated out.

Sensitivity and ex vivo validation of finite element models of the domestic pig cranium

PubMed Central

Bright, Jen A; Rayfield, Emily J

2011-01-01

A finite element (FE) validation and sensitivity study was undertaken on a modern domestic pig cranium. Bone strain data were collected ex vivo from strain gauges, and compared with results from specimen-specific FE models. An isotropic, homogeneous model was created, then input parameters were altered to investigate model sensitivity. Heterogeneous, isotropic models investigated the effects of a constant-thickness, stiffer outer layer (representing cortical bone) atop a more compliant interior (representing cancellous bone). Loading direction and placement of strain gauges were also varied, and the use of 2D membrane elements at strain gauge locations as a method of projecting 3D model strains into the plane of the gauge was investigated. The models correctly estimate the loading conditions of the experiment, yet at some locations fail to reproduce correct principal strain magnitudes, and hence strain ratios. Principal strain orientations are predicted well. The initial model was too stiff by approximately an order of magnitude. Introducing a compliant interior reported strain magnitudes more similar to the ex vivo results without notably affecting strain orientations, ratios or contour patterns, suggesting that this simple heterogeneity was the equivalent of reducing the overall stiffness of the model. Models were generally insensitive to moderate changes in loading direction or strain gauge placement, except in the squamosal portion of the zygomatic arch. The use of membrane elements made negligible differences to the reported strains. The models therefore seem most sensitive to changes in material properties, and suggest that failure to model local heterogeneity in material properties and structure of the bone may be responsible for discrepancies between the experimental and model results. This is partially attributable to a lack of resolution in the CT scans from which the model was built, and partially due to an absence of detailed material properties data for pig cranial bone. Thus, caution is advised when using FE models to estimate absolute numerical values of breaking stress and bite force unless detailed input parameters are available. However, if the objective is to compare relative differences between models, the fact that the strain environment is replicated well means that such investigations can be robust. PMID:21718316

Can We Trust Measures of Political Trust? Assessing Measurement Equivalence in Diverse Regime Types.

PubMed

Schneider, Irena

2017-01-01

Do standard "trust in government" survey questions deliver measures which are reliable and equivalent in meaning across diverse regime types? I test for the measurement equivalence of political trust in a sample of 35 former Soviet and European countries using the 2010 Life in Transition Survey II conducted by the World Bank and European Bank for Reconstruction and Development. Employing multiple group confirmatory factor analysis, I find that trust perceptions in central political institutions differ from (1) trust in regional and local political institutions, (2) trust in protective institutions like the armed forces and police and (3) trust in order institutions like the courts and police. Four measurement models achieve partial metric invariance and two reach partial scalar invariance in most countries, allowing for comparisons of correlates using latent factors from each model. I also found some clustering of measurement error and variation in the dimensionality of political trust between democratic and autocratic portions of the sample. On some measurement parameters, therefore, respondents in diverse cultures and regime types do not have equivalent understandings of political trust. The findings offer both optimism and a note of caution for researchers using political trust measures in cross-regime contexts.

Anatexis at the roof of an oceanic magma chamber at IODP Site 1256 (equatorial Pacific): an experimental study

NASA Astrophysics Data System (ADS)

Erdmann, Martin; Fischer, Lennart A.; France, Lydéric; Zhang, Chao; Godard, Marguerite; Koepke, Jürgen

2015-04-01

Replenished axial melt lenses at fast-spreading mid-oceanic ridges may move upward and intrude into the overlying hydrothermally altered sheeted dikes, resulting in high-grade contact metamorphism with the potential to trigger anatexis in the roof rocks. Assumed products of this process are anatectic melts of felsic composition and granoblastic, two-pyroxene hornfels, representing the residue after partial melting. Integrated Ocean Drilling Program Expeditions 309, 312, and 335 at Site 1256 (eastern equatorial Pacific) sampled such a fossilized oceanic magma chamber. In this study, we simulated magma chamber roof rock anatectic processes by performing partial melting experiments using six different protoliths from the Site 1256 sheeted dike complex, spanning a lithological range from poorly to strongly altered basalts to partially or fully recrystallized granoblastic hornfels. Results show that extensively altered starting material lacking primary magmatic minerals cannot reproduce the chemistry of natural felsic rocks recovered in ridge environments, especially elements sensitive to hydrothermal alteration (e.g., K, Cl). Natural geochemical trends are reproduced through partial melting of moderately altered basalts from the lower sheeted dikes. Two-pyroxene hornfels, the assumed residue, were reproduced only at low melting degrees (<20 vol%). The overall amphibole absence in the experiments confirms the natural observation that amphibole is not produced during peak metamorphism. Comparing experimental products with the natural equivalents reveals that water activity ( aH2O) was significantly reduced during anatectic processes, mainly based on lower melt aluminum oxide and lower plagioclase anorthite content at lower aH2O. High silica melt at the expected temperature (1000-1050 °C; peak thermal overprint of two-pyroxene hornfels) could only be reproduced in the experimental series performed at aH2O = 0.1.

Formation of Partially and Fully Elaborated Generalized Equivalence Classes

ERIC Educational Resources Information Center

Fields, Lanny; Moss, Patricia

2008-01-01

Most complex categories observed in real-world settings consist of perceptually disparate stimuli, such as a picture of a person's face, the person's name as written, and the same name as heard, as well as dimensional variants of some or all of these stimuli. The stimuli function as members of a single partially or fully elaborated generalized…

Complete passive vibration suppression using multi-layered piezoelectric element, inductor, and resistor

NASA Astrophysics Data System (ADS)

Yamada, Keisuke

2017-01-01

This paper describes passive technique for suppressing vibration in flexible structures using a multi-layered piezoelectric element, an inductor, and a resistor. The objective of using a multi-layered piezoelectric element is to increase its capacitance. A piezoelectric element with a large capacitance value does not require an active electrical circuit to simulate an inductor with a large inductance value. The effect of multi-layering of piezoelectric elements was theoretically analyzed through an equivalent transformation of a multi-layered piezoelectric element into a single-layered piezoelectric element. The governing equations were derived using this equivalent transformation. The effect of the resistances of the inductor and piezoelectric elements were considered because the sum of these resistances may exceed the optimum resistance. The performance of the passive vibration suppression using an LR circuit was compared to that of the method where a resistive circuit is used assuming that the sum of the resistances of the inductor and piezoelectric elements exceeds the optimum resistance. The effectiveness of the proposed method and theoretical analysis was verified through simulations and experiments.

Isotopic evolution of Mauna Kea volcano: Results from the initial phase of the Hawaii Scientific Drilling Project

USGS Publications Warehouse

Lassiter, J.C.; DePaolo, D.J.; Tatsumoto, M.

1996-01-01

We have examined the Sr, Nd, and Pb isotopic compositions of Mauna Kea lavas recovered by the first drilling phase of the Hawaii Scientific Drilling Project. These lavas, which range in age from ???200 to 400 ka, provide a detailed record of chemical and isotopic changes in basalt composition during the shied/postshield transition and extend our record of Mauna Kea volcanism to a late-shield period roughly equivalent to the last ???100 ka of Mauna Loa activity. Stratigraphic variations in isotopic composition reveal a gradual shift over time toward a more depleted source composition (e.g., higher 143Nd/144Nd, lower 87Sr/86Sr, and lower 3He/4He). This gradual evolution is in sharp contrast with the abrupt appearance of alkalic lavas at ???240 ka recorded by the upper 50 m of Mauna Kea lavas from the core. Intercalated tholeiitic and alkalic lavas from the uppermost Mauna Kea section are isotopically indistinguishable. Combined with major element evidence (e.g., decreasing SiO2 and increasing FeO) that the depth of melt segregation increased during the transition from tholeiitic to alkalic volcanism, the isotopic similarity of tholeiitic and alkalic lavas argues against significant lithosphere involvement during melt generation. Instead, the depleted isotopic signatures found in late shield-stage lavas are best explained by increasing the proportion of melt generated from a depleted upper mantle component entrained and heated by the rising central plume. Direct comparison of Mauna Kea and Mauna Loa lavas erupted at equivalent stages in these volcanoes' life cycles reveals persistent chemical and isotopic differences independent of the temporal evolution of each volcano. The oldest lavas recovered from the drillcore are similar to modern Kilauea lavas, but are distinct from Mauna Loa lavas. Mauna Kea lavas have higher 143Nd/144Nd and 206Pb/204Pb and lower 87Sr/86Sr. Higher concentrations of incompatible trace elements in primary magmas, lower SiO2, and higher FeO also indicate that Mauna Kea lavas formed through smaller degrees of partial melting at greater depth than Mauna Loa lavas. These chemical and isotopic differences are consistently found between volcanoes along the western "Loa" and eastern "Kea" trends and reflect large-scale variations in source composition and melting environment. We propose a simple model of a radially zoned plume centered beneath the Loa trend. Loa trend lavas generated from the hot plume axis reflect high degrees of partial melting from a source containing a mixture of enriched plume-source material and entrained lower mantle. Kea trend lavas, in contrast, are generated from the cooler, peripheral portions of the plume, record lower degrees of partial melting, and tap a source containing a greater proportion of depleted upper mantle.

Visual Equivalence and Amodal Completion in Cuttlefish

PubMed Central

Lin, I-Rong; Chiao, Chuan-Chin

2017-01-01

Modern cephalopods are notably the most intelligent invertebrates and this is accompanied by keen vision. Despite extensive studies investigating the visual systems of cephalopods, little is known about their visual perception and object recognition. In the present study, we investigated the visual processing of the cuttlefish Sepia pharaonis, including visual equivalence and amodal completion. Cuttlefish were trained to discriminate images of shrimp and fish using the operant conditioning paradigm. After cuttlefish reached the learning criteria, a series of discrimination tasks were conducted. In the visual equivalence experiment, several transformed versions of the training images, such as images reduced in size, images reduced in contrast, sketches of the images, the contours of the images, and silhouettes of the images, were used. In the amodal completion experiment, partially occluded views of the original images were used. The results showed that cuttlefish were able to treat the training images of reduced size and sketches as the visual equivalence. Cuttlefish were also capable of recognizing partially occluded versions of the training image. Furthermore, individual differences in performance suggest that some cuttlefish may be able to recognize objects when visual information was partly removed. These findings support the hypothesis that the visual perception of cuttlefish involves both visual equivalence and amodal completion. The results from this research also provide insights into the visual processing mechanisms used by cephalopods. PMID:28220075

On the hierarchy of partially invariant submodels of differential equations

NASA Astrophysics Data System (ADS)

Golovin, Sergey V.

2008-07-01

It is noted that the partially invariant solution (PIS) of differential equations in many cases can be represented as an invariant reduction of some PISs of the higher rank. This introduces a hierarchic structure in the set of all PISs of a given system of differential equations. An equivalence of the two-step and the direct ways of construction of PISs is proved. The hierarchy simplifies the process of enumeration and analysis of partially invariant submodels to the given system of differential equations. In this framework, the complete classification of regular partially invariant solutions of ideal MHD equations is given.

Reducing the duality gap in partially convex programming

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

Correa, R.

1994-12-31

We consider the non-linear minimization program {alpha} = min{sub z{element_of}D, x{element_of}C}{l_brace}f{sub 0}(z, x) : f{sub i}(z, x) {<=} 0, i {element_of} {l_brace}1, ..., m{r_brace}{r_brace} where f{sub i}(z, {center_dot}) are convex functions, C is convex and D is compact. Following Ben-Tal, Eiger and Gershowitz we prove the existence of a partial dual program whose optimum is arbitrarily close to {alpha}. The idea, corresponds to the branching principle in Branch and Bound methods. We describe such a kind of algorithm for obtaining the desired partial dual.

A MULTI-ELEMENT THICK GAS ELECTRON MULTIPLIER-BASED MICRODOSEMETER FOR MEASUREMENT OF NEUTRONS DOSE-EQUIVALENT: A MONTE CARLO STUDY.

PubMed

Moslehi, A; Raisali, G

2017-11-01

To determine the dose-equivalent of neutrons in an extended energy range, in the present work a multi-element thick gas electron multiplier-based microdosemeter made of PMMA (Perspex) walls of 10 mm in thickness is designed. Each cavity is filled with the propane-based tissue-equivalent (TE) gas simulating 1 µm of tissue. Also, a few weight fractions of 3He are assumed to be added to the TE gas. The dose-equivalents are determined for 11 neutron energies between thermal and 14 MeV using the lineal energy distributions calculated by Geant4 simulation toolkit and also the lineal energy-based quality factors. The results show that by adding 0.04% of 3He to the TE gas in each cavity, an energy-independent dose-equivalent response within 30% uncertainty around a median value of 0.91 in the above energy range is achieved. It is concluded that after its construction, the studied microdosemeter can be used to measure the dose-equivalent of neutrons, favorably. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Selected trace elements in the Sacramento River, California: occurrence and distribution.

PubMed

Taylor, H E; Antweiler, R C; Roth, D A; Alpers, C N; Dileanis, P

2012-05-01

The impact of trace elements from the Iron Mountain Superfund site on the Sacramento River and selected tributaries is examined. The concentration and distribution of many trace elements-including aluminum, arsenic, boron, barium, beryllium, bismuth, cadmium, cerium, cobalt, chromium, cesium, copper, dysprosium, erbium, europium, iron, gadolinium, holmium, potassium, lanthanum, lithium, lutetium, manganese, molybdenum, neodymium, nickel, lead, praseodymium, rubidium, rhenium, antimony, selenium, samarium, strontium, terbium, thallium, thulium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc, and zirconium-were measured using a combination of inductively coupled plasma-mass spectrometry and inductively coupled plasma-atomic emission spectrometry. Samples were collected using ultraclean techniques at selected sites in tributaries and the Sacramento River from below Shasta Dam to Freeport, California, at six separate time periods from mid-1996 to mid-1997. Trace-element concentrations in dissolved (ultrafiltered [0.005-μm pore size]) and colloidal material, isolated at each site from large volume samples, are reported. For example, dissolved Zn ranged from 900 μg/L at Spring Creek (Iron Mountain acid mine drainage into Keswick Reservoir) to 0.65 μg/L at the Freeport site on the Sacramento River. Zn associated with colloidal material ranged from 4.3 μg/L (colloid-equivalent concentration) in Spring Creek to 21.8 μg/L at the Colusa site on the Sacramento River. Virtually all of the trace elements exist in Spring Creek in the dissolved form. On entering Keswick Reservoir, the metals are at least partially converted by precipitation or adsorption to the particulate phase. Despite this observation, few of the elements are removed by settling; instead the majority is transported, associated with colloids, downriver, at least to the Bend Bridge site, which is 67 km from Keswick Dam. Most trace elements are strongly associated with the colloid phase going downriver under both low- and high-flow conditions.

Improved optical filter

NASA Technical Reports Server (NTRS)

Title, A. M.

1978-01-01

Filter includes partial polarizer between birefrigent elements. Plastic film on partial polarizer compensates for any polarization rotation by partial polarizer. Two quarter-wave plates change incident, linearly polarized light into elliptically polarized light.

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.

Petrochemical evolution of the White Mfolozi Granite pluton: Evidence for a late Palaeoarchaean A-type granite from the SE Kaapvaal Craton, South Africa

NASA Astrophysics Data System (ADS)

Misra, Saumitra; Reinhardt, Jürgen; Wilson, Allan H.

2017-08-01

One of the major limitations in understanding the geochemical evolution of the Kaapvaal Craton, South Africa, is the scarcity of whole rock trace element data of the granitoid and other rocks compared to the vastness of this cratonic block. Here we present new XRF major oxide and ICP-MS trace element analyses of the White Mfolozi Granitoid (WMG) pluton, SE Kaapvaal Craton, which suggest that the 3.25 Ga (U-Pb zircon age) old WMG pluton is a peraluminous A-type granite and could be equivalent to the intrusive potassic granite phase of the Anhalt Granitoid suite, occurring to the North of the WMG pluton. The pluton was generated by batch partial melting of a pre-existing TTG source in two major phases under relatively anhydrous conditions, and the heat of partial melting could have been provided by a voluminous mantle-derived mafic magma, which intruded into mid-crustal levels (c. 17 km), perhaps during a period of crustal extension. The estimated pressure and temperature of generation of the WMG parent magma with average molar [or/(or + ab)] 0.48 could be 500 MPa and close to 1000 °C, respectively, when compared with the results of experimental petrology. Interstitial occurrence of relatively iron-rich biotite [Mg/(Mg + Fe) 0.41-0.45] suggests that the final temperature of crystallization of the pluton was close to 800 °C. An important magmatic event following the main phase of partial melting was limited mixing between the intrusive mafic magma and co-existing newly generated granitic melt. This magma mixing resulted in distinct variations in SiO2 and a low initial Sr isotopic ratio (0.7013) of the WMG pluton. Although both the models of partial melting of quartzo-feldspathic sources and fractional crystallization of basaltic magmas with or without crustal assimilation have been proposed for the origin of A-type granites, the model of magmatic evolution of the WMG pluton presented here can also be an alternative model for the generation of A-type granites. In this model, post-partial melting magma mixing is perhaps critical in explaining the Daly gap in composition and extreme variations in chemical (e.g., SiO2) and isotopic compositions observed in many bimodal A-type granite suites. The emplacement of the oldest known A-type granitoid suite in the Kaapvaal Craton, the WMG pluton, marks a period of stabilization of the craton before erosion and deposition of the overlying volcano-sedimentary succession of the Pongola Supergroup.

Experimental study and finite element analysis based on equivalent load method for laser ultrasonic measurement of elastic constants.

PubMed

Zhan, Yu; Liu, Changsheng; Zhang, Fengpeng; Qiu, Zhaoguo

2016-07-01

The laser ultrasonic generation of Rayleigh surface wave and longitudinal wave in an elastic plate is studied by experiment and finite element method. In order to eliminate the measurement error and the time delay of the experimental system, the linear fitting method of experimental data is applied. The finite element analysis software ABAQUS is used to simulate the propagation of Rayleigh surface wave and longitudinal wave caused by laser excitation on a sheet metal sample surface. The equivalent load method is proposed and applied. The pulsed laser is equivalent to the surface load in time and space domain to meet the Gaussian profile. The relationship between the physical parameters of the laser and the load is established by the correction factor. The numerical solution is in good agreement with the experimental result. The simple and effective numerical and experimental methods for laser ultrasonic measurement of the elastic constants are demonstrated. Copyright © 2016. Published by Elsevier B.V.

On the application of a new thermal diagnostic model: the passive elements equivalent in term of ventilation inside a room

NASA Astrophysics Data System (ADS)

El Khattabi, El Mehdi; Mharzi, Mohamed; Raefat, Saad; Meghari, Zouhair

2018-05-01

In this paper, the thermal equivalence of the passive elements of a room in a building located in Fez-Morocco has been studied. The possibility of replacing them with a semi-passive element such as ventilation has been appraised. For this aim a Software in Fortran taking into account the meteorological external conditions along with different parameters of the building envelope has been performed. A new computational approach is adapted to determinate the temperature distribution throughout the building multilayer walls. A novel equation gathering the internal temperature with the external conditions, and the building envelope has been deduced in transient state.

Equivalent Linearization Analysis of Geometrically Nonlinear Random Vibrations Using Commercial Finite Element Codes

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Muravyov, Alexander A.

2002-01-01

Two new equivalent linearization implementations for geometrically nonlinear random vibrations are presented. Both implementations are based upon a novel approach for evaluating the nonlinear stiffness within commercial finite element codes and are suitable for use with any finite element code having geometrically nonlinear static analysis capabilities. The formulation includes a traditional force-error minimization approach and a relatively new version of a potential energy-error minimization approach, which has been generalized for multiple degree-of-freedom systems. Results for a simply supported plate under random acoustic excitation are presented and comparisons of the displacement root-mean-square values and power spectral densities are made with results from a nonlinear time domain numerical simulation.

Should massive rotator cuff tears be reconstructed even when only partially repairable?

PubMed

Godenèche, Arnaud; Freychet, Benjamin; Lanzetti, Riccardo Maria; Clechet, Julien; Carrillon, Yannick; Saffarini, Mo

2017-07-01

(1) To evaluate midterm functional outcomes of arthroscopic repair of massive rotator cuff tears and (2) to determine the prognostic factors that could influence outcome. The hypothesis was that both partial and complete repairs would result in equivalent improvement of clinical score. From a prospective series of 525 rotator cuff repairs, we analysed records of the 73 patients who were treated for massive tears. The median follow-up was 41 months (range 29-55), and functional outcome was evaluated using the Constant score, shoulder strength, and subjective shoulder value. The median CS improved from 34 points to 81 points (p < 0.001). The scores were better for both types of two-tendon tears, posterosuperior (83, n = 33) and anterosuperior (85, n = 13) (n.s.), than for three-tendon tears (74, n = 27) (p < 0.001). The scores were also better when fatty infiltration was of stage I (84, n = 28) than of stage II (78, n = 34) (p < 0.001) or stage III (74, n = 11) (p = 0.04). The scores were only slightly higher for completely reparable tears (81.5, n = 50) than for partially reparable tears (79, n = 23) (n.s.). Ultrasonic examination revealed incomplete healing, in 10 of the 50 completely repaired tears, and in 11 of the 23 partially repaired tears. The results of the present study compare favourably with those in recent literature and confirm the hypothesis that both partial and complete repairs of massive rotator cuff tears produce equivalent improvements of Constant scores. The clinical relevance of these observations is that even if repairs of two-tendon tears result in superior functional outcomes, repairs of three-tendon tears produce equivalent 'relative' improvement that grants sufficient patient satisfaction and autonomy. Comparative case series, Level IV.

A Posteriori Finite Element Bounds for Sensitivity Derivatives of Partial-Differential-Equation Outputs. Revised

NASA Technical Reports Server (NTRS)

Lewis, Robert Michael; Patera, Anthony T.; Peraire, Jaume

1998-01-01

We present a Neumann-subproblem a posteriori finite element procedure for the efficient and accurate calculation of rigorous, 'constant-free' upper and lower bounds for sensitivity derivatives of functionals of the solutions of partial differential equations. The design motivation for sensitivity derivative error control is discussed; the a posteriori finite element procedure is described; the asymptotic bounding properties and computational complexity of the method are summarized; and illustrative numerical results are presented.

Enhancers and super-enhancers have an equivalent regulatory role in embryonic stem cells through regulation of single or multiple genes

PubMed Central

Moorthy, Sakthi D.; Davidson, Scott; Shchuka, Virlana M.; Singh, Gurdeep; Malek-Gilani, Nakisa; Langroudi, Lida; Martchenko, Alexandre; So, Vincent; Macpherson, Neil N.; Mitchell, Jennifer A.

2017-01-01

Transcriptional enhancers are critical for maintaining cell-type–specific gene expression and driving cell fate changes during development. Highly transcribed genes are often associated with a cluster of individual enhancers such as those found in locus control regions. Recently, these have been termed stretch enhancers or super-enhancers, which have been predicted to regulate critical cell identity genes. We employed a CRISPR/Cas9-mediated deletion approach to study the function of several enhancer clusters (ECs) and isolated enhancers in mouse embryonic stem (ES) cells. Our results reveal that the effect of deleting ECs, also classified as ES cell super-enhancers, is highly variable, resulting in target gene expression reductions ranging from 12% to as much as 92%. Partial deletions of these ECs which removed only one enhancer or a subcluster of enhancers revealed partially redundant control of the regulated gene by multiple enhancers within the larger cluster. Many highly transcribed genes in ES cells are not associated with a super-enhancer; furthermore, super-enhancer predictions ignore 81% of the potentially active regulatory elements predicted by cobinding of five or more pluripotency-associated transcription factors. Deletion of these additional enhancer regions revealed their robust regulatory role in gene transcription. In addition, select super-enhancers and enhancers were identified that regulated clusters of paralogous genes. We conclude that, whereas robust transcriptional output can be achieved by an isolated enhancer, clusters of enhancers acting on a common target gene act in a partially redundant manner to fine tune transcriptional output of their target genes. PMID:27895109

SAGUARO: a finite-element computer program for partially saturated porous flow problems

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

Eaton, R.R.; Gartling, D.K.; Larson, D.E.

1983-06-01

SAGUARO is a finite element computer program designed to calculate two-dimensional flow of mass and energy through porous media. The media may be saturated or partially saturated. SAGUARO solves the parabolic time-dependent mass transport equation which accounts for the presence of partially saturated zones through the use of highly non-linear material characteristic curves. The energy equation accounts for the possibility of partially saturated regions by adjusting the thermal capacitances and thermal conductivities according to the volume fraction of water present in the local pores. Program capabilities, user instructions and a sample problem are presented in this manual.

The cross-cultural equivalence of participation instruments: a systematic review.

PubMed

Stevelink, S A M; van Brakel, W H

2013-07-01

Concepts such as health-related quality of life, disability and participation may differ across cultures. Consequently, when assessing such a concept using a measure developed elsewhere, it is important to test its cultural equivalence. Previous research suggested a lack of cultural equivalence testing in several areas of measurement. This paper reviews the process of cross-cultural equivalence testing of instruments to measure participation in society. An existing cultural equivalence framework was adapted and used to assess participation instruments on five categories of equivalence: conceptual, item, semantic, measurement and operational equivalence. For each category, several aspects were rated, resulting in an overall category rating of 'minimal/none', 'partial' or 'extensive'. The best possible overall study rating was five 'extensive' ratings. Articles were included if the instruments focussed explicitly on measuring 'participation' and were theoretically grounded in the ICIDH(-2) or ICF. Cross-validation articles were only included if it concerned an adaptation of an instrument developed in a high or middle-income country to a low-income country or vice versa. Eight cross-cultural validation studies were included in which five participation instruments were tested (Impact on Participation and Autonomy, London Handicap Scale, Perceived Impact and Problem Profile, Craig Handicap Assessment Reporting Technique, Participation Scale). Of these eight studies, only three received at least two 'extensive' ratings for the different categories of equivalence. The majority of the cultural equivalence ratings given were 'partial' and 'minimal/none'. The majority of the 'none/minimal' ratings were given for item and measurement equivalence. The cross-cultural equivalence testing of the participation instruments included leaves much to be desired. A detailed checklist is proposed for designing a cross-validation study. Once a study has been conducted, the checklist can be used to ensure comprehensive reporting of the validation (equivalence) testing process and its results. • Participation instruments are often used in a different cultural setting than initial developed for. • The conceptualization of participation may vary across cultures. Therefore, cultural equivalence – the extent to which an instrument is equally suitable for use in two or more cultures – is an important concept to address. • This review showed that the process of cultural equivalence testing of the included participation instruments was often addressed insufficiently. • Clinicians should be aware that application of participations instruments in a different culture than initially developed for needs prior testing of cultural validity in the next context.

Clinical diagnosis of partial or complete anterior cruciate ligament tears using patients' history elements and physical examination tests.

PubMed

Décary, Simon; Fallaha, Michel; Belzile, Sylvain; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Feldman, Debbie; Sylvestre, Marie-Pierre; Vendittoli, Pascal-André; Desmeules, François

2018-01-01

To assess the diagnostic validity of clusters combining history elements and physical examination tests to diagnose partial or complete anterior cruciate ligament (ACL) tears. Prospective diagnostic study. Orthopaedic clinics (n = 2), family medicine clinics (n = 2) and community-dwelling. Consecutive patients with a knee complaint (n = 279) and consulting one of the participating orthopaedic surgeons (n = 3) or sport medicine physicians (n = 2). Not applicable. History elements and physical examination tests performed independently were compared to the reference standard: an expert physicians' composite diagnosis including history elements, physical tests and confirmatory magnetic resonance imaging. Penalized logistic regression (LASSO) was used to identify history elements and physical examination tests associated with the diagnosis of ACL tear and recursive partitioning was used to develop diagnostic clusters. Diagnostic accuracy measures including sensitivity (Se), specificity (Sp), predictive values and positive and negative likelihood ratios (LR+/-) with associated 95% confidence intervals (CI) were calculated. Forty-three individuals received a diagnosis of partial or complete ACL tear (15.4% of total cohort). The Lachman test alone was able to diagnose partial or complete ACL tears (LR+: 38.4; 95%CI: 16.0-92.5). Combining a history of trauma during a pivot with a "popping" sensation also reached a high diagnostic validity for partial or complete tears (LR+: 9.8; 95%CI: 5.6-17.3). Combining a history of trauma during a pivot, immediate effusion after trauma and a positive Lachman test was able to identify individuals with a complete ACL tear (LR+: 17.5; 95%CI: 9.8-31.5). Finally, combining a negative history of pivot or a negative popping sensation during trauma with a negative Lachman or pivot shift test was able to exclude both partial or complete ACL tears (LR-: 0.08; 95%CI: 0.03-0.24). Diagnostic clusters combining history elements and physical examination tests can support the differential diagnosis of ACL tears compared to various knee disorders.

47 CFR 51.316 - Conversion of unbundled network elements and services.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 3 2011-10-01 2011-10-01 false Conversion of unbundled network elements and... § 51.316 Conversion of unbundled network elements and services. (a) Upon request, an incumbent LEC shall convert a wholesale service, or group of wholesale services, to the equivalent unbundled network...

47 CFR 51.316 - Conversion of unbundled network elements and services.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Conversion of unbundled network elements and... § 51.316 Conversion of unbundled network elements and services. (a) Upon request, an incumbent LEC shall convert a wholesale service, or group of wholesale services, to the equivalent unbundled network...

On-line monitoring of the crystallization process: relationship between crystal size and electrical impedance spectra

NASA Astrophysics Data System (ADS)

Zhao, Yanlin; Yao, Jun; Wang, Mi

2016-07-01

On-line monitoring of crystal size in the crystallization process is crucial to many pharmaceutical and fine-chemical industrial applications. In this paper, a novel method is proposed for the on-line monitoring of the cooling crystallization process of L-glutamic acid (LGA) using electrical impedance spectroscopy (EIS). The EIS method can be used to monitor the growth of crystal particles relying on the presence of an electrical double layer on the charged particle surface and the polarization of double layer under the excitation of alternating electrical field. The electrical impedance spectra and crystal size were measured on-line simultaneously by an impedance analyzer and focused beam reflectance measurement (FBRM), respectively. The impedance spectra were analyzed using the equivalent circuit model and the equivalent circuit elements in the model can be obtained by fitting the experimental data. Two equivalent circuit elements, including capacitance (C 2) and resistance (R 2) from the dielectric polarization of the LGA solution and crystal particle/solution interface, are in relation with the crystal size. The mathematical relationship between the crystal size and the equivalent circuit elements can be obtained by a non-linear fitting method. The function can be used to predict the change of crystal size during the crystallization process.

An equivalent domain integral method in the two-dimensional analysis of mixed mode crack problems

NASA Technical Reports Server (NTRS)

Raju, I. S.; Shivakumar, K. N.

1990-01-01

An equivalent domain integral (EDI) method for calculating J-integrals for two-dimensional cracked elastic bodies is presented. The details of the method and its implementation are presented for isoparametric elements. The EDI method gave accurate values of the J-integrals for two mode I and two mixed mode problems. Numerical studies showed that domains consisting of one layer of elements are sufficient to obtain accurate J-integral values. Two procedures for separating the individual modes from the domain integrals are presented.

Fiber Composite Sandwich Thermostructural Behavior: Computational Simulation

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Aiello, R. A.; Murthy, P. L. N.

1986-01-01

Several computational levels of progressive sophistication/simplification are described to computationally simulate composite sandwich hygral, thermal, and structural behavior. The computational levels of sophistication include: (1) three-dimensional detailed finite element modeling of the honeycomb, the adhesive and the composite faces; (2) three-dimensional finite element modeling of the honeycomb assumed to be an equivalent continuous, homogeneous medium, the adhesive and the composite faces; (3) laminate theory simulation where the honeycomb (metal or composite) is assumed to consist of plies with equivalent properties; and (4) derivations of approximate, simplified equations for thermal and mechanical properties by simulating the honeycomb as an equivalent homogeneous medium. The approximate equations are combined with composite hygrothermomechanical and laminate theories to provide a simple and effective computational procedure for simulating the thermomechanical/thermostructural behavior of fiber composite sandwich structures.

Archaean ultra-depleted komatiites formed by hydrous melting of cratonic mantle.

PubMed

Wilson, A H; Shirey, S B; Carlson, R W

2003-06-19

Komatiites are ultramafic volcanic rocks containing more than 18 per cent MgO (ref. 1) that erupted mainly in the Archaean era (more than 2.5 gigayears ago). Although such compositions occur in later periods of Earth history (for example, the Cretaceous komatiites of Gorgona Island), the more recent examples tend to have lower MgO content than their Archaean equivalents. Komatiites are also characterized by their low incompatible-element content, which is most consistent with their generation by high degrees of partial melting (30-50 per cent). Current models for komatiite genesis include the melting of rock at great depth in plumes of hot, diapirically rising mantle or the melting of relatively shallow mantle rocks at less extreme, but still high, temperatures caused by fluxing with water. Here we report a suite of ultramafic lava flows from the Commondale greenstone belt, in the southern part of the Kaapvaal Craton, which represents a previously unrecognized type of komatiite with exceptionally high forsterite content of its igneous olivines, low TiO(2)/Al(2)O(3) ratio, high silica content, extreme depletion in rare-earth elements and low Re/Os ratio. We suggest a model for their formation in which a garnet-enriched residue left by earlier cratonic volcanism was melted by hydration from a subducting slab.

How to disentangle the Cosmic Web?

NASA Astrophysics Data System (ADS)

Shandarin, Sergei; Medvedev, Mikhail

2015-04-01

The Cosmic Web is a complicated highly-entangled geometrical object formed from remarkably simple - Gaussian - initial conditions. The full complexity of the Web can be fully appreciated in the six-dimensional phase space only, which study is, however, impractical due to numerous reasons. Instead, we suggest to use Lagrangian submanifold, i.e., the mapping x = x(q) , where x and q are three dimensional vectors representing Eulerian and Lagrangian coordinates. Being fully equivalent in dynamical sense to the phase space, it has the advantage of being a single valued and also metric space. In addition, we propose a new computational paradigm for the analysis of substructure of the Cosmic Web in cosmological cold dark matter (CDM) simulations. We introduce a new data-field - the flip-flop field - which carries wealth of information about the history and dynamics of the structure formation in the universe. The flip-flop (FF) field is an ordered data set in Lagrangian space representing the number of sign reversals of an elementary volume of each collisionless fluid element represented by a computational particle in a N-body simulation. This FF-field is effectively a multi-stream counter of each substructure element of the Cosmic Web. We demonstrate that the very rich subst Partially supported by DOE Grant DE-FG02-07ER54940 and NSF Grant AST-1209665.

A normal tissue dose response model of dynamic repair processes.

PubMed

Alber, Markus; Belka, Claus

2006-01-07

A model is presented for serial, critical element complication mechanisms for irradiated volumes from length scales of a few millimetres up to the entire organ. The central element of the model is the description of radiation complication as the failure of a dynamic repair process. The nature of the repair process is seen as reestablishing the structural organization of the tissue, rather than mere replenishment of lost cells. The interactions between the cells, such as migration, involved in the repair process are assumed to have finite ranges, which limits the repair capacity and is the defining property of a finite-sized reconstruction unit. Since the details of the repair processes are largely unknown, the development aims to make the most general assumptions about them. The model employs analogies and methods from thermodynamics and statistical physics. An explicit analytical form of the dose response of the reconstruction unit for total, partial and inhomogeneous irradiation is derived. The use of the model is demonstrated with data from animal spinal cord experiments and clinical data about heart, lung and rectum. The three-parameter model lends a new perspective to the equivalent uniform dose formalism and the established serial and parallel complication models. Its implications for dose optimization are discussed.

40 CFR 1065.1001 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engine parameters. Emission-control system means any device, system, or element of design that controls.... Nonmethane hydrocarbon equivalent (NMHCE) means the sum of the carbon mass contributions of non-oxygenated... of 1.85:1. Total hydrocarbon equivalent (THCE) means the sum of the carbon mass contributions of non...

40 CFR 1065.1001 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... engine parameters. Emission-control system means any device, system, or element of design that controls.... Nonmethane hydrocarbon equivalent (NMHCE) means the sum of the carbon mass contributions of non-oxygenated... of 1.85:1. Total hydrocarbon equivalent (THCE) means the sum of the carbon mass contributions of non...

Analysis of microstrip dipoles and slots transversely coupled to a microstrip line using the FDTD method

NASA Technical Reports Server (NTRS)

Tulintseff, A. N.

1993-01-01

Printed dipole elements and their complement, linear slots, are elementary radiators that have found use in low-profile antenna arrays. Low-profile antenna arrays, in addition to their small size and low weight characteristics, offer the potential advantage of low-cost, high-volume production with easy integration with active integrated circuit components. The design of such arrays requires that the radiation and impedance characteristics of the radiating elements be known. The FDTD (Finite-Difference Time-Domain) method is a general, straight-forward implementation of Maxwell's equations and offers a relatively simple way of analyzing both printed dipole and slot elements. Investigated in this work is the application of the FDTD method to the analysis of printed dipole and slot elements transversely coupled to an infinite transmission line in a multilayered configuration. Such dipole and slot elements may be used in dipole and slot series-fed-type linear arrays, where element offsets and interelement line lengths are used to obtain the desired amplitude distribution and beam direction, respectively. The design of such arrays is achieved using transmission line theory with equivalent circuit models for the radiating elements. In an equivalent circuit model, the dipole represents a shunt impedance to the transmission line, where the impedance is a function of dipole offset, length, and width. Similarly, the slot represents a series impedance to the transmission line. The FDTD method is applied to single dipole and slot elements transversely coupled to an infinite microstrip line using a fixed rectangular grid with Mur's second order absorbing boundary conditions. Frequency-dependent circuit and scattering parameters are obtained by saving desired time-domain quantities and using the Fourier transform. A Gaussian pulse excitation is applied to the microstrip transmission line, where the resulting reflected signal due to the presence of the radiating element is used to determine the equivalent element impedance.

Research on the equivalent circuit model of a circular flexural-vibration-research on the equivalent circuit model of a circular flexural-vibration-mode piezoelectric transformer with moderate thickness.

PubMed

Huang, Yihua; Huang, Wenjin; Wang, Qinglei; Su, Xujian

2013-07-01

The equivalent circuit model of a piezoelectric transformer is useful in designing and optimizing the related driving circuits. Based on previous work, an equivalent circuit model for a circular flexural-vibration-mode piezoelectric transformer with moderate thickness is proposed and validated by finite element analysis. The input impedance, voltage gain, and efficiency of the transformer are determined through computation. The basic behaviors of the transformer are shown by numerical results.

Selected trace elements in the Sacramento River, California: Occurrence and distribution

USGS Publications Warehouse

Taylor, Howard E.; Antweiler, Ronald C.; Roth, David A.; Dileanis, Peter D.; Alpers, Charles N.

2012-01-01

The impact of trace elements from the Iron Mountain Superfund site on the Sacramento River and selected tributaries is examined. The concentration and distribution of many trace elements—including aluminum, arsenic, boron, barium, beryllium, bismuth, cadmium, cerium, cobalt, chromium, cesium, copper, dysprosium, erbium, europium, iron, gadolinium, holmium, potassium, lanthanum, lithium, lutetium, manganese, molybdenum, neodymium, nickel, lead, praseodymium, rubidium, rhenium, antimony, selenium, samarium, strontium, terbium, thallium, thulium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc, and zirconium—were measured using a combination of inductively coupled plasma-mass spectrometry and inductively coupled plasma-atomic emission spectrometry. Samples were collected using ultraclean techniques at selected sites in tributaries and the Sacramento River from below Shasta Dam to Freeport, California, at six separate time periods from mid-1996 to mid-1997. Trace-element concentrations in dissolved (ultrafiltered [0.005-μm pore size]) and colloidal material, isolated at each site from large volume samples, are reported. For example, dissolved Zn ranged from 900 μg/L at Spring Creek (Iron Mountain acid mine drainage into Keswick Reservoir) to 0.65 μg/L at the Freeport site on the Sacramento River. Zn associated with colloidal material ranged from 4.3 μg/L (colloid-equivalent concentration) in Spring Creek to 21.8 μg/L at the Colusa site on the Sacramento River. Virtually all of the trace elements exist in Spring Creek in the dissolved form. On entering Keswick Reservoir, the metals are at least partially converted by precipitation or adsorption to the particulate phase. Despite this observation, few of the elements are removed by settling; instead the majority is transported, associated with colloids, downriver, at least to the Bend Bridge site, which is 67 km from Keswick Dam. Most trace elements are strongly associated with the colloid phase going downriver under both low- and high-flow conditions.

40 CFR 1065.1001 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-control system means any device, system, or element of design that controls or reduces the emissions of... equivalent (NMHCE) means the sum of the carbon mass contributions of non-oxygenated nonmethane hydrocarbons... of 1.85:1. Total hydrocarbon equivalent (THCE) means the sum of the carbon mass contributions of non...

Non-volatile copolymer compositions for fabricating gel element microarrays

PubMed Central

Golova, Julia B.; Chernov, Boris K.; Perov, Alexander N.; Reynolds, Jennifer; Linger, Yvonne L.; Kukhtin, Alexander; Chandler, Darrell P.

2011-01-01

By modifying polymer compositions and cross-linking reagents, we have developed a simple yet effective manufacturing strategy for copolymerized three-dimensional gel element arrays. A new gel-forming monomer (2-(hydroxyethyl) methacrylamide; HEMAA) was used that possesses low volatility and improves the stability of copolymerized gel element arrays to on-chip thermal cycling procedures relative to previously used monomers. Probe immobilization efficiency within the new polymer was 55%, equivalent to that obtained with acrylamide (AA) and methacrylamide (MA) monomers. Non-specific binding of single stranded targets was equivalent for all monomers. Increasing cross-linker chain length improved hybridization kinetics and end-point signal intensities relative to N,N-methylenebisacrylamide (Bis). The new copolymer formulation was successfully applied to a model orthopox array. Because HEMAA greatly simplifies gel element array manufacture, we expect it (in combination with new cross-linkers described herein) to find widespread application in microarray science. PMID:22033291

Backscatter laser depolarization studies of simulated stratospheric aerosols - Crystallized sulfuric acid droplets

NASA Technical Reports Server (NTRS)

Sassen, Kenneth; Zhao, Hongjie; Yu, Bing-Kun

1989-01-01

The optical depolarizing properties of simulated stratospheric aerosols were studied in laboratory laser (0.633 micrometer) backscattering experiments for application to polarization lidar observations. Clouds composed of sulfuric acid solution droplets, some treated with ammonia gas, were observed during evaporation. The results indicate that the formation of minute ammonium sulfate particles from the evaporation of acid droplets produces linear depolarization ratios of beta equivalent to 0.02, but beta equivalent to 0.10 to 0.15 are generated from aged acid cloud aerosols and acid droplet crystalization effects following the introduction of ammonia gas into the chamber. It is concluded that partially crystallized sulfuric acid droplets are a likely candidate for explaining the lidar beta equivalent to 0.10 values that have been observed in the lower stratosphere in the absence of the relatively strong backscattering from homogeneous sulfuric acid droplet (beta equivalent to 0) or ice crystal (beta equivalent to 0.5) clouds.

Backscatter laser depolarization studies of simulated stratospheric aerosols: Crystallized sulfuric acid droplets

NASA Technical Reports Server (NTRS)

Sassen, Kenneth; Zhao, Hongjie; Yu, Bing-Kun

1988-01-01

The optical depolarizing properties of simulated stratospheric aerosols were studied in laboratory laser (0.633 micrometer) backscattering experiments for application to polarization lidar observations. Clouds composed of sulfuric acid solution droplets, some treated with ammonia gas, were observed during evaporation. The results indicate that the formation of minute ammonium sulfate particles from the evaporation of acid droplets produces linear depolarization ratios of beta equivalent to 0.02, but beta equivalent to 0.10 to 0.15 are generated from aged acid cloud aerosols and acid droplet crystallization effects following the introduction of ammonia gas into the chamber. It is concluded that partially crystallized sulfuric acid droplets are a likely candidate for explaining the lidar beta equivalent to 0.10 values that have been observed in the lower stratosphere in the absence of the relatively strong backscattering from homogeneous sulfuric acid droplet (beta equivalent to 0) or ice crystal (beta equivalent to 0.5) clouds.

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

Wintermeyer, Niklas; Winters, Andrew R., E-mail: awinters@math.uni-koeln.de; Gassner, Gregor J.

We design an arbitrary high-order accurate nodal discontinuous Galerkin spectral element approximation for the non-linear two dimensional shallow water equations with non-constant, possibly discontinuous, bathymetry on unstructured, possibly curved, quadrilateral meshes. The scheme is derived from an equivalent flux differencing formulation of the split form of the equations. We prove that this discretization exactly preserves the local mass and momentum. Furthermore, combined with a special numerical interface flux function, the method exactly preserves the mathematical entropy, which is the total energy for the shallow water equations. By adding a specific form of interface dissipation to the baseline entropy conserving schememore » we create a provably entropy stable scheme. That is, the numerical scheme discretely satisfies the second law of thermodynamics. Finally, with a particular discretization of the bathymetry source term we prove that the numerical approximation is well-balanced. We provide numerical examples that verify the theoretical findings and furthermore provide an application of the scheme for a partial break of a curved dam test problem.« less

The Behaviour of Naturally Debonded Composites Due to Bending Using a Meso-Level Model

NASA Astrophysics Data System (ADS)

Lord, C. E.; Rongong, J. A.; Hodzic, A.

2012-06-01

Numerical simulations and analytical models are increasingly being sought for the design and behaviour prediction of composite materials. The use of high-performance composite materials is growing in both civilian and defence related applications. With this growth comes the necessity to understand and predict how these new materials will behave under their exposed environments. In this study, the displacement behaviour of naturally debonded composites under out-of-plane bending conditions has been investigated. An analytical approach has been developed to predict the displacement response behaviour. The analytical model supports multi-layered composites with full and partial delaminations. The model can be used to extract bulk effective material properties in which can be represented, later, as an ESL (Equivalent Single Layer). The friction between each of the layers is included in the analytical model and is shown to have distinct behaviour for these types of composites. Acceptable agreement was observed between the model predictions, the ANSYS finite element model, and the experiments.

Diffusion tensor driven contour closing for cell microinjection targeting.

PubMed

Becattini, Gabriele; Mattos, Leonardo S; Caldwell, Darwin G

2010-01-01

This article introduces a novel approach to robust automatic detection of unstained living cells in bright-field (BF) microscope images with the goal of producing a target list for an automated microinjection system. The overall image analysis process is described and includes: preprocessing, ridge enhancement, image segmentation, shape analysis and injection point definition. The developed algorithm implements a new version of anisotropic contour completion (ACC) based on the partial differential equation (PDE) for heat diffusion which improves the cell segmentation process by elongating the edges only along their tangent direction. The developed ACC algorithm is equivalent to a dilation of the binary edge image with a continuous elliptic structural element that takes into account local orientation of the contours preventing extension towards normal direction. Experiments carried out on real images of 10 to 50 microm CHO-K1 adherent cells show a remarkable reliability in the algorithm along with up to 85% success for cell detection and injection point definition.

Dual Functionalization of White Phosphorus: Formation, Characterization, and Reactivity of Rare-Earth-Metal Cyclo-P3 Complexes.

PubMed

Du, Shanshan; Yin, Jianhao; Chi, Yue; Xu, Ling; Zhang, Wen-Xiong

2017-12-11

The [3+1] fragmentation reaction of rare-earth metallacyclopentadienes 1 a-c with 0.5 equivalents of P 4 affords a series of rare-earth metal cyclo-P 3 complexes 2 a-c and a phospholyl anion 3. 2 a-c demonstrate an unusual η 3 coordination mode with one P-P bond featuring partial π-bonding character. 2 a-c are the first cyclo-P 3 complexes of rare-earth metals, and also the first organo-substituted polyphosphides in the category of Group 3 and f-block elements. Rare-earth metallacyclopentadienes play a dual role in the combination of aromatization and Diels-Alder reaction. Compounds 2 a-c can coordinate to one or two [W(CO) 5 ] units, yielding 4 a-c or 5 c, respectively. Furthermore, oxidation of 2 a with p-benzoquinone produces its corresponding phospholyllithium and regenerated P 4 . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Relationship of Optical Anomalies, Zoning, and Microtopography in Vesuvianite from Jeffrey Mine, Asbestos, Quebec

NASA Astrophysics Data System (ADS)

Smith, Varina Campbell

The role of growth steps in inducing disequilibrium is investigated in crystals of vesuvianite from the Jeffrey mine, Asbestos, Quebec, using optical microscopy, atomic force microscopy, electron microprobe analysis, and single-crystal X-ray diffraction. The selective uptake of elements Fe and Al by asymmetric growth-steps on three crystallographic forms, {100}, {110}, and {121}, is documented. The prisms {100} and {110} show hillocks that display kinetically controlled oscillatory zoning along growth steps parallel to <010> and <11¯1>, but not on vicinal faces defined by [001] steps. Sector-specific zoning of extinction angles and 2V angles indicate different degrees of optical dissymmetrization in crystals spanning a range of growth habits. Unit-cell parameters and the presence of violating reflections confirm sectoral deviations from P4/nnc symmetry in the prismatic sectors. The partial loss of three glide planes follows the pattern expected from order of the cations Al and Fe induced by tangential selectivity at the edge of non-equivalent steps during layer-by-layer growth.

Absorption and scattering by fractal aggregates and by their equivalent coated spheres

NASA Astrophysics Data System (ADS)

Kandilian, Razmig; Heng, Ri-Liang; Pilon, Laurent

2015-01-01

This paper demonstrates that the absorption and scattering cross-sections and the asymmetry factor of randomly oriented fractal aggregates of spherical monomers can be rapidly estimated as those of coated spheres with equivalent volume and average projected area. This was established for fractal aggregates with fractal dimension ranging from 2.0 to 3.0 and composed of up to 1000 monodisperse or polydisperse monomers with a wide range of size parameter and relative complex index of refraction. This equivalent coated sphere approximation was able to capture the effects of both multiple scattering and shading among constituent monomers on the integral radiation characteristics of the aggregates. It was shown to be superior to the Rayleigh-Debye-Gans approximation and to the equivalent coated sphere approximation proposed by Latimer. However, the scattering matrix element ratios of equivalent coated spheres featured large angular oscillations caused by internal reflection in the coating which were not observed in those of the corresponding fractal aggregates. Finally, the scattering phase function and the scattering matrix elements of aggregates with large monomer size parameter were found to have unique features that could be used in remote sensing applications.

Equivalent reduced model technique development for nonlinear system dynamic response

NASA Astrophysics Data System (ADS)

Thibault, Louis; Avitabile, Peter; Foley, Jason; Wolfson, Janet

2013-04-01

The dynamic response of structural systems commonly involves nonlinear effects. Often times, structural systems are made up of several components, whose individual behavior is essentially linear compared to the total assembled system. However, the assembly of linear components using highly nonlinear connection elements or contact regions causes the entire system to become nonlinear. Conventional transient nonlinear integration of the equations of motion can be extremely computationally intensive, especially when the finite element models describing the components are very large and detailed. In this work, the equivalent reduced model technique (ERMT) is developed to address complicated nonlinear contact problems. ERMT utilizes a highly accurate model reduction scheme, the System equivalent reduction expansion process (SEREP). Extremely reduced order models that provide dynamic characteristics of linear components, which are interconnected with highly nonlinear connection elements, are formulated with SEREP for the dynamic response evaluation using direct integration techniques. The full-space solution will be compared to the response obtained using drastically reduced models to make evident the usefulness of the technique for a variety of analytical cases.

[Effect of muscle biofidelity on thoracic impact biomechanical response of a six-year-old child using finite element method].

PubMed

Cui, Shihai; Shan, Leilei; Li, Haiyan; Lu, Wenle; He, Lijuan; Ruan, Shijie

2017-02-01

Finite element(FE) model of thorax with high biofidelity is one of the most important methods to investigate thoracic injury mechanism because of the absence of pediatric cadaver experiments. Based on the validated thorax finite element model, the FE models with equivalent muscles and real geometric muscles were developed respectively, and the effect of muscle biofidelity on thoracic injury was analyzed with reconstructing pediatric cadaver thorax impact experiments. The simulation results showed that the thoracic impact force, the maximum displacement and the maximum von-Mises stress of FE models with equivalent muscles were slightly greater than those from FE models with real geometric muscles, and the maximum principal strains of heart and lung were a little lower. And the correlation coefficient between cadaver corridor and FE model with real muscles was also greater than that between cadaver corridor and FE model with equivalent muscles. As a conclusion, the FE models with real geometric muscles can accurately reflect the biomechanical response of thorax during the impact.

Aeroelastic Stability of Rotor Blades Using Finite Element Analysis

NASA Technical Reports Server (NTRS)

Chopra, I.; Sivaneri, N.

1982-01-01

The flutter stability of flap bending, lead-lag bending, and torsion of helicopter rotor blades in hover is investigated using a finite element formulation based on Hamilton's principle. The blade is divided into a number of finite elements. Quasi-steady strip theory is used to evaluate the aerodynamic loads. The nonlinear equations of motion are solved for steady-state blade deflections through an iterative procedure. The equations of motion are linearized assuming blade motion to be a small perturbation about the steady deflected shape. The normal mode method based on the coupled rotating natural modes is used to reduce the number of equations in the flutter analysis. First the formulation is applied to single-load-path blades (articulated and hingeless blades). Numerical results show very good agreement with existing results obtained using the modal approach. The second part of the application concerns multiple-load-path blades, i.e. bearingless blades. Numerical results are presented for several analytical models of the bearingless blade. Results are also obtained using an equivalent beam approach wherein a bearingless blade is modelled as a single beam with equivalent properties. Results show the equivalent beam model.

Expanding the Interaction Equivalency Theorem

ERIC Educational Resources Information Center

Rodriguez, Brenda Cecilia Padilla; Armellini, Alejandro

2015-01-01

Although interaction is recognised as a key element for learning, its incorporation in online courses can be challenging. The interaction equivalency theorem provides guidelines: Meaningful learning can be supported as long as one of three types of interactions (learner-content, learner-teacher and learner-learner) is present at a high level. This…

Challenges and opportunities in establishing scientific and regulatory standards for determining therapeutic equivalence of modified-release products: Workshop summary report.

PubMed

Chen, Mei-Ling; Shah, Vinod P; Ganes, Derek; Midha, Kamal K; Caro, James; Nambiar, Prabu; Rocci, Mario L; Thombre, Avinash G; Abrahamsson, Bertil; Conner, Dale; Davit, Barbara; Fackler, Paul; Farrell, Colm; Gupta, Suneel; Katz, Russell; Mehta, Mehul; Preskorn, Sheldon H; Sanderink, Gerard; Stavchansky, Salomon; Temple, Robert; Wang, Yaning; Winkle, Helen; Yu, Lawrence

2010-09-01

Modified-release (MR) products are complex dosage forms designed to release drug in a controlled manner to achieve the desired efficacy and safety profiles. Inappropriate control of drug release from such products may result in reduced efficacy or increased toxicity. This paper is a summary report of the American Association of Pharmaceutical Scientists, International Pharmaceutical Federation, and Product Quality Research Institute workshop titled "Challenges and Opportunities in Establishing Scientific and Regulatory Standards for Assuring Therapeutic Equivalence of Modified Release Products", held October 1-2, 2009, in Baltimore, Maryland. The workshop provided an opportunity for pharmaceutical scientists from academia, industry, and regulatory agencies to discuss current regulatory expectations and industry practices for evaluating the pharmaceutical equivalence and bioequivalence of oral MR products. In the case of conventional monophasic MR formulations, the current regulatory approaches and criteria for bioequivalence evaluation were considered adequate for the assessment of therapeutic equivalence and inter-changeability of drug products. Additional measures may occasionally be needed to determine the bioequivalence of multiphasic MR products. The metric of partial AUC proposed by the US Food and Drug Administration received broad support as an additional measure for evaluating bioequivalence of multiphasic MR products designed to have a rapid onset of drug action followed by sustained response. The cutoff for partial AUCs may be based on the pharmacokinetic/pharmacodynamic or pharmacokinetic/ response characteristics of the products under examination. If the new metric is highly variable, the bioequivalence limits may be set based on the known within-subject variability for the reference product. The current regulatory approaches and criteria for bioequivalence evaluation were considered adequate for the assessment of therapeutic equivalence and interchangeability of conventional monophasic MR products. Additional measures may occasionally be needed to establish the bioequivalence of multiphasic MR products, and development of such measures is an important objective. The metric of partial AUC was proposed for products designed to have a rapid drug action followed by sustained response. Copyright © 2010 Excerpta Medica Inc. All rights reserved.

A Model for Siderophile Element Distribution in Planetary Differentiation

NASA Technical Reports Server (NTRS)

Humayun, M.; Rushmer, T.; Rankenburg, K.; Brandon, A. D.

2005-01-01

Planetary differentiation begins with partial melting of small planetesimals. At low degrees of partial melting, a sulfur-rich liquid segregates by physical mechanisms including deformation-assisted porous flow. Experimental studies of the physical mechanisms by which Fe-S melts segregate from the silicate matrix of a molten H chondrite are part of a companion paper. Geochemical studies of these experimental products revealed that metallic liquids were in equilibrium with residual metal in the H chondrite matrix. This contribution explores the geochemical signatures produced by early stages of core formation. Particularly, low-degree partial melt segregation of Fe-S liquids leaves residual metal in the silicate matrix. Some achondrites appear to be residues of partial melting, e.g., ureilites, which are known to contain metal. The metal in these achondrites may show a distinct elemental signature. To quantify the effect of sulfur on siderophile element contents of residual metal we have developed a model based on recent parametrizations of equilibrium solid metal-liquid metal partitioning experiments.

Direct computation of thermodynamic properties of chemically reacting air with consideration to CFD

NASA Astrophysics Data System (ADS)

Iannelli, Joe

2003-10-01

This paper details a two-equation procedure to calculate exactly mass and mole fractions, pressure, temperature, specific heats, speed of sound and the thermodynamic and jacobian partial derivatives of pressure and temperature for a five-species chemically reacting equilibrium air. The procedure generates these thermodynamic properties using as independent variables either pressure and temperature or density and internal energy, for CFD applications. An original element in this procedure consists in the exact physically meaningful solution of the mass-fraction and mass-action equations. Air-equivalent molecular masses for oxygen and nitrogen are then developed to account, within a mixture of only oxygen and nitrogen, for the presence of carbon dioxide, argon and the other noble gases within atmospheric air. The mathematical formulation also introduces a versatile system non-dimensionalization that makes the procedure uniformly applicable to flows ranging from shock-tube flows with zero initial velocity to aerothermodynamic flows with supersonic/hypersonic free-stream Mach numbers. Over a temperature range of more than 10000 K and pressure and density ranges corresponding to an increase in altitude in standard atmosphere of 30000 m above sea level, the predicted distributions of mole fractions, constant-volume specific heat, and speed of sound for the model five species agree with independently published results, and all the calculated thermodynamic properties, including their partial derivatives, remain continuous, smooth, and physically meaningful.

MEMS 3-DoF gyroscope design, modeling and simulation through equivalent circuit lumped parameter model

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

Mian, Muhammad Umer, E-mail: umermian@gmail.com; Khir, M. H. Md.; Tang, T. B.

Pre-fabrication, behavioural and performance analysis with computer aided design (CAD) tools is a common and fabrication cost effective practice. In light of this we present a simulation methodology for a dual-mass oscillator based 3 Degree of Freedom (3-DoF) MEMS gyroscope. 3-DoF Gyroscope is modeled through lumped parameter models using equivalent circuit elements. These equivalent circuits consist of elementary components which are counterpart of their respective mechanical components, used to design and fabricate 3-DoF MEMS gyroscope. Complete designing of equivalent circuit model, mathematical modeling and simulation are being presented in this paper. Behaviors of the equivalent lumped models derived for themore » proposed device design are simulated in MEMSPRO T-SPICE software. Simulations are carried out with the design specifications following design rules of the MetalMUMPS fabrication process. Drive mass resonant frequencies simulated by this technique are 1.59 kHz and 2.05 kHz respectively, which are close to the resonant frequencies found by the analytical formulation of the gyroscope. The lumped equivalent circuit modeling technique proved to be a time efficient modeling technique for the analysis of complex MEMS devices like 3-DoF gyroscopes. The technique proves to be an alternative approach to the complex and time consuming couple field analysis Finite Element Analysis (FEA) previously used.« less

Equivalent circuit consideration of frequency-shift-type acceleration sensor

NASA Astrophysics Data System (ADS)

Sasaki, Yoshifumi; Sugawara, Sumio; Kudo, Subaru

2018-07-01

In this paper, an electrical equivalent circuit for the piezoelectrically driven frequency-shift-type acceleration sensor model is represented, and the equivalent circuit constants including the effect of the axial force are clarified for the first time. The results calculated by the finite element method are compared with the experimentally measured ones of the one-axis sensor of trial production. The result shows that the analyzed values almost agree with the measured ones, and that the equivalent circuit representation of the sensor is useful for electrical engineers in order to easily analyze the characteristics of the sensors.

Clinical diagnosis of partial or complete anterior cruciate ligament tears using patients' history elements and physical examination tests

PubMed Central

Fallaha, Michel; Belzile, Sylvain; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Feldman, Debbie; Sylvestre, Marie-Pierre; Vendittoli, Pascal-André; Desmeules, François

2018-01-01

Objective To assess the diagnostic validity of clusters combining history elements and physical examination tests to diagnose partial or complete anterior cruciate ligament (ACL) tears. Design Prospective diagnostic study. Settings Orthopaedic clinics (n = 2), family medicine clinics (n = 2) and community-dwelling. Participants Consecutive patients with a knee complaint (n = 279) and consulting one of the participating orthopaedic surgeons (n = 3) or sport medicine physicians (n = 2). Interventions Not applicable. Main outcome measures History elements and physical examination tests performed independently were compared to the reference standard: an expert physicians’ composite diagnosis including history elements, physical tests and confirmatory magnetic resonance imaging. Penalized logistic regression (LASSO) was used to identify history elements and physical examination tests associated with the diagnosis of ACL tear and recursive partitioning was used to develop diagnostic clusters. Diagnostic accuracy measures including sensitivity (Se), specificity (Sp), predictive values and positive and negative likelihood ratios (LR+/-) with associated 95% confidence intervals (CI) were calculated. Results Forty-three individuals received a diagnosis of partial or complete ACL tear (15.4% of total cohort). The Lachman test alone was able to diagnose partial or complete ACL tears (LR+: 38.4; 95%CI: 16.0–92.5). Combining a history of trauma during a pivot with a “popping” sensation also reached a high diagnostic validity for partial or complete tears (LR+: 9.8; 95%CI: 5.6–17.3). Combining a history of trauma during a pivot, immediate effusion after trauma and a positive Lachman test was able to identify individuals with a complete ACL tear (LR+: 17.5; 95%CI: 9.8–31.5). Finally, combining a negative history of pivot or a negative popping sensation during trauma with a negative Lachman or pivot shift test was able to exclude both partial or complete ACL tears (LR-: 0.08; 95%CI: 0.03–0.24). Conclusion Diagnostic clusters combining history elements and physical examination tests can support the differential diagnosis of ACL tears compared to various knee disorders. PMID:29894492

Chemical Properties of Elements 99 and 100 [Einsteinium and Fermium

DOE R&D Accomplishments Database

Seaborg, G. T.; Thompson, S. G.; Harvey, B. G.; Choppin, G. R.

1954-07-23

A description of some of the chemical properties and of the methods used in the separations of elements 99 [Einsteinium] and 100 [Fermium] are given. The new elements exhibit the properties expected for the tenth and eleventh actinide elements. Attempts to produce an oxidation state greater than III of element 99 have been unsuccessful. In normal aqueous media only the III state of element 100 appears to exist. The relative spacings of the elution peaks of the new elements in some separations with ion exchange resin columns are the same as the relative spacings of the homologous lanthanide elements. The results of experiments involving cation exchange resins with very concentrated hydrochloric acid eluant show that the new elements, like the earlier actinides, are more strongly complexed than the lanthanides. The new elements also exist partially as anions in concentrated hydrochloric acid, as do earlier actinide elements, and they may be partially separated from each other by means of ion exchange resins. With some eluants interesting reversals of elution positions are observed in the region Bk-Cf-99-100, indicating complex ion formation involving unusual factors.

Uranium and minor-element partitioning in Fe-Ti oxides and zircon from partially melted granodiorite, Crater Lake, Oregon

USGS Publications Warehouse

Tourrette, T.Z.L.; Burnett, D.S.; Bacon, C.R.

1991-01-01

Crystal-liquid partitioning in Fe-Ti oxides and zircon was studied in partially melted granodiorite blocks ejected during the climactic eruption of Mt. Mazama (Crater Lake), Oregon. The blocks, which contain up to 33% rhyolite glass (75 wt% SiO2), are interpreted to be portions of the magma chamber walls that were torn off during eruption. The glass is clear and well homogenized for all measured elements except Zr. Results for Fe-Ti oxides give DUoxide/liq ??? 0.1. Partitioning of Mg, Mn, Al, Si, V, and Cr in Fe-Ti oxides indicates that grains surrounded by glass are moderately well equilibrated with the melt for many of the minor elements, while those that are inclusions in relict plagioclase are not. Uranium and ytterbium inhomogeneities in zircons indicate that the zircons have only partially equilibrated with the melt and that uranium appears to have been diffusing out of the zircons faster than the zircons were dissolving. Minimum U, Y, and P concentrations in zircons give maximum DUzrc/liq = 13,DYzrc/liq = 23, and DPzrc/liq = 1, but these are considerably lower than reported by other workers for U and Y. Based on our measurements and given their low abundances in most rocks, Fe-Ti oxides probably do not play a major role in U-Th fractionation during partial melting. The partial melts were undersaturated with zircon and apatite, but both phases are present in our samples. This demonstrates an actual case of non-equilibrium source retention of accessory phases, which in general could be an important trace-element fractionation mechanism. Our results do not support the hypothesis that liquid structure is the dominant factor controlling trace-element partitioning in high-silica rhyolites. Rough calculations based on Zr gradients in the glass indicate that the samples could have been partially molten for 800 to 8000 years. ?? 1991.

29 CFR 1960.67 - Federal agency certification of the injury and illness annual summary (OSHA 300-A or equivalent).

Code of Federal Regulations, 2011 CFR

2011-07-01

... annual summary (OSHA 300-A or equivalent). 1960.67 Section 1960.67 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) BASIC PROGRAM ELEMENTS FOR FEDERAL EMPLOYEE OCCUPATIONAL SAFETY AND HEALTH PROGRAMS AND RELATED MATTERS Recordkeeping and...

29 CFR 1960.67 - Federal agency certification of the injury and illness annual summary (OSHA 300-A or equivalent).

Code of Federal Regulations, 2010 CFR

2010-07-01

... annual summary (OSHA 300-A or equivalent). 1960.67 Section 1960.67 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) BASIC PROGRAM ELEMENTS FOR FEDERAL EMPLOYEE OCCUPATIONAL SAFETY AND HEALTH PROGRAMS AND RELATED MATTERS Recordkeeping and...

77 FR 48448 - Connect America Fund; A National Broadband Plan for Our Future; Establishing Just and Reasonable...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-14

... to the total reduction required in 2012. In addition, the Bureau clarifies that non-commercial mobile... than their functionally equivalent interstate rates in making this transition. 6. Carriers and state... functionally equivalent interstate switched access rate element rates. Other of the carrier's intrastate...

40 CFR 92.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Auxiliary emission control device (AECD) means any element of design which senses temperature, locomotive... those devices, systems or elements of design which control or reduce the emission of substances from an... Equivalent means the sum of the carbon mass contributions of non-oxygenated hydrocarbons, alcohols and...

40 CFR 92.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Auxiliary emission control device (AECD) means any element of design which senses temperature, locomotive... those devices, systems or elements of design which control or reduce the emission of substances from an... Equivalent means the sum of the carbon mass contributions of non-oxygenated hydrocarbons, alcohols and...

40 CFR 92.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Auxiliary emission control device (AECD) means any element of design which senses temperature, locomotive... those devices, systems or elements of design which control or reduce the emission of substances from an... Equivalent means the sum of the carbon mass contributions of non-oxygenated hydrocarbons, alcohols and...

40 CFR 94.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... emission control device (AECD) means any element of design which senses temperature, vessel speed, engine... means those devices, systems or elements of design which control or reduce the emission of substances.... Total Hydrocarbon Equivalent means the sum of the carbon mass contributions of non-oxygenated...

40 CFR 94.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... emission control device (AECD) means any element of design which senses temperature, vessel speed, engine... means those devices, systems or elements of design which control or reduce the emission of substances.... Total Hydrocarbon Equivalent means the sum of the carbon mass contributions of non-oxygenated...

40 CFR 94.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... emission control device (AECD) means any element of design which senses temperature, vessel speed, engine... means those devices, systems or elements of design which control or reduce the emission of substances.... Total Hydrocarbon Equivalent means the sum of the carbon mass contributions of non-oxygenated...

40 CFR 92.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Auxiliary emission control device (AECD) means any element of design which senses temperature, locomotive... those devices, systems or elements of design which control or reduce the emission of substances from an... Equivalent means the sum of the carbon mass contributions of non-oxygenated hydrocarbons, alcohols and...

40 CFR 94.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... emission control device (AECD) means any element of design which senses temperature, vessel speed, engine... means those devices, systems or elements of design which control or reduce the emission of substances.... Total Hydrocarbon Equivalent means the sum of the carbon mass contributions of non-oxygenated...

40 CFR 92.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Auxiliary emission control device (AECD) means any element of design which senses temperature, locomotive... those devices, systems or elements of design which control or reduce the emission of substances from an... Equivalent means the sum of the carbon mass contributions of non-oxygenated hydrocarbons, alcohols and...

40 CFR 94.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... emission control device (AECD) means any element of design which senses temperature, vessel speed, engine... means those devices, systems or elements of design which control or reduce the emission of substances.... Total Hydrocarbon Equivalent means the sum of the carbon mass contributions of non-oxygenated...

5 CFR 430.207 - Monitoring performance.

Code of Federal Regulations, 2013 CFR

2013-01-01

... appraisal program shall include methods for appraising each critical and non-critical element during the appraisal period. Performance on each critical and non-critical element shall be appraised against its... provide assistance whenever performance is determined to be below “Fully Successful” or equivalent but...

5 CFR 430.207 - Monitoring performance.

Code of Federal Regulations, 2011 CFR

2011-01-01

... appraisal program shall include methods for appraising each critical and non-critical element during the appraisal period. Performance on each critical and non-critical element shall be appraised against its... provide assistance whenever performance is determined to be below “Fully Successful” or equivalent but...

The CoRoT target HD 49933: a possible seismic signature of heavy elements ionization in the deep convective zone

NASA Astrophysics Data System (ADS)

Brito, Ana; Lopes, Ilídio

2017-04-01

We use a seismic diagnostic, based on the derivative of the phase shift of the acoustic waves reflected by the surface, to probe the outer layers of the star HD 49933. This diagnostic is particularly sensitive to partial ionization processes occurring above the base of the convective zone. The regions of partial ionization of light elements, hydrogen and helium, have well-known seismological signatures. In this work, we detect a different seismic signature in the acoustic frequencies, which we showed to correspond to the location where the partial ionization of heavy elements occurs. The location of the corresponding acoustic glitch lies between the region of the second ionization of helium and the base of the convective zone, approximately 5 per cent below the surface of the stars.

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

Caruso, M., E-mail: mcaruso@ugr.es; Fanchiotti, H.; Canal, C.A. Garcia

An equivalence between the Schroedinger dynamics of a quantum system with a finite number of basis states and a classical dynamics is presented. The equivalence is an isomorphism that connects in univocal way both dynamical systems. We treat the particular case of neutral kaons and found a class of electric networks uniquely related to the kaon system finding the complete map between the matrix elements of the effective Hamiltonian of kaons and those elements of the classical dynamics of the networks. As a consequence, the relevant {epsilon} parameter that measures CP violation in the kaon system is completely determined inmore » terms of network parameters. - Highlights: > We provide a formal equivalence between classical and quantum dynamics. > We make use of the decomplexification concept. > Neutral kaon systems can be represented by electric circuits. > CP symmetry violation can be taken into account by non-reciprocity. > Non-reciprocity is represented by gyrators.« less

Optimum structural sizing of conventional cantilever and joined wing configurations using equivalent beam models

NASA Technical Reports Server (NTRS)

Hajela, P.; Chen, J. L.

1986-01-01

The present paper describes an approach for the optimum sizing of single and joined wing structures that is based on representing the built-up finite element model of the structure by an equivalent beam model. The low order beam model is computationally more efficient in an environment that requires repetitive analysis of several trial designs. The design procedure is implemented in a computer program that requires geometry and loading data typically available from an aerodynamic synthesis program, to create the finite element model of the lifting surface and an equivalent beam model. A fully stressed design procedure is used to obtain rapid estimates of the optimum structural weight for the beam model for a given geometry, and a qualitative description of the material distribution over the wing structure. The synthesis procedure is demonstrated for representative single wing and joined wing structures.

Composition of the earth's upper mantle-I. Siderophile trace elements in ultramafic nodules

USGS Publications Warehouse

Morgan, J.W.; Wandless, G.A.; Petrie, R.K.; Irving, A.J.

1981-01-01

Seven siderophile elements (Au, Ge, Ir, Ni, Pd, Os, Re) were determined by radiochemical neutron activation analysis in 19 ultramafic rocks, which are spinel lherzollites-xenoliths from North and Central America, Hawaii and Australia, and garnet Iherzolitexenoliths from Lesotho. Abundances of the platinum metals are very uniform in spinel lherzolites averaging 3.4 ?? 1.2 ppb Os, 3.7 ?? 1.1 ppb Ir, and 4.6 ?? 2.0 ppb Pd. Sheared garnet lherzolite PHN 1611 has similar abundances of these elements, but in 4 granulated garnet lherzolites, abundances are more variable. In all samples, the Pt metals retain cosmic ( Cl-chondrite) ratios. Abundances of Au and Re vary more than those of Pt metals, but the Au/Re ratio remains close to the cosmic value. The fact that higher values of Au and Re approach cosmic proportions with respect to the Pt metals, suggests that Au and Re have been depleted in some ultramafic rocks from an initially chondrite-like pattern equivalent to about 0.01 of Cl chondrite abundances. The relative enrichment of Au and Re in crustal rocks is apparently the result of crust-mantle fractionation and does not require a special circumstance of core-mantle partitioning. Abundances of moderately volatile elements Ni, Co and Ge are very uniform in all rocks, and are much higher than those of the highly siderophile elements Au, Ir, Pd, Os and Re. When normalized to Cl chondrites, abundances of Ni and Co are nearly identical, averaging 0.20 ?? 0.02 and 0.22 ?? 0.02, respectively; but Ge is only 0.027 ?? 0.004. The low abundance of Ge relative to Ni and Co is apparently a reflection of the general depletion of volatile elements in the Earth. The moderately siderophile elements cannot be derived from the same source as the highly siderophile elements because of the marked difference in Cl chondrite-normalized abundances and patterns. We suggest that most of the Ni, Co and Ge were enriched in the silicate by the partial oxidation of pre-existing volatile-poor Fe-Ni, whereas the corresponding highly siderophile elements remained sequestered by the surviving metal. The highly siderophile elements may have been introduced by a population of ~103 large (~1022 g) planetisimals, similar to those forming the lunar mare basins. ?? 1981.

Develop real-time dosimetry concepts and instrumentation for long term missions

NASA Technical Reports Server (NTRS)

Braby, L. A.

1982-01-01

The development of a rugged portable instrument to evaluate dose and dose equivalent is described. A tissue-equivalent proportional counter simulating a 2 micrometer spherical tissue volume was operated satisfactorily for over a year. The basic elements of the electronic system were designed and tested. And finally, the most suitable mathematical technique for evaluating dose equivalent with a portable instrument was selected. Design and fabrication of a portable prototype, based on the previously tested circuits, is underway.

Precision Tests of a Quantum Hall Effect Device DC Equivalent Circuit Using Double-Series and Triple-Series Connections

PubMed Central

Jeffery, A.; Elmquist, R. E.; Cage, M. E.

1995-01-01

Precision tests verify the dc equivalent circuit used by Ricketts and Kemeny to describe a quantum Hall effect device in terms of electrical circuit elements. The tests employ the use of cryogenic current comparators and the double-series and triple-series connection techniques of Delahaye. Verification of the dc equivalent circuit in double-series and triple-series connections is a necessary step in developing the ac quantum Hall effect as an intrinsic standard of resistance. PMID:29151768

Recent Development of Multigrid Algorithms for Mixed and Noncomforming Methods for Second Order Elliptical Problems

NASA Technical Reports Server (NTRS)

Chen, Zhangxin; Ewing, Richard E.

1996-01-01

Multigrid algorithms for nonconforming and mixed finite element methods for second order elliptic problems on triangular and rectangular finite elements are considered. The construction of several coarse-to-fine intergrid transfer operators for nonconforming multigrid algorithms is discussed. The equivalence between the nonconforming and mixed finite element methods with and without projection of the coefficient of the differential problems into finite element spaces is described.

Partially filled electrodes for digital microfluidic devices

NASA Astrophysics Data System (ADS)

Pyne, D. G.; Salman, W. M.; Abdelgawad, M.; Sun, Y.

2013-07-01

As digital microfluidics technology evolves, the need for integrating additional elements (e.g., sensing/detection and heating elements) on the electrode increases. Consequently, electrode area for droplet actuation is reduced to create space for accommodating these additional elements, which undesirably affects force generation. Electrodes cannot simply be scaled larger to compensate for this loss of force, as this would also increase droplet volume and thereby compromise the advantages thought in miniaturization. Here, we present a study evaluating, numerically with preliminary experimental verification, different partially filled electrode designs and suggesting designs that combine high actuation forces with a large reduction in electrode area.

Full-vectorial finite element method in a cylindrical coordinate system for loss analysis of photonic wire bends

NASA Astrophysics Data System (ADS)

Kakihara, Kuniaki; Kono, Naoya; Saitoh, Kunimasa; Koshiba, Masanori

2006-11-01

This paper presents a new full-vectorial finite-element method in a local cylindrical coordinate system, to effectively analyze bending losses in photonic wires. The discretization is performed in the cross section of a three-dimensional curved waveguide, using hybrid edge/nodal elements. The solution region is truncated by anisotropic, perfectly matched layers in the cylindrical coordinate system, to deal properly with leaky modes of the waveguide. This approach is used to evaluate bending losses in silicon wire waveguides. The numerical results of the present approach are compared with results calculated with an equivalent straight waveguide approach and with reported experimental data. These comparisons together demonstrate the validity of the present approach based on the cylindrical coordinate system and also clarifies the limited validity of the equivalent straight waveguide approximation.

Gap Excitations and Series Loads in Microstrip Lines: Equivalent Network Characterization with Application to THz Circuits

NASA Technical Reports Server (NTRS)

Neto, Andrea; Siegel, Peter H.

2001-01-01

At submillimeter wavelengths typical gap discontinuities in microstrip, CPW lines or at antenna terminals, which might contain diodes or active elements, cannot be viewed as simple quasi statically evaluated lumped elements. Planar Schottky diodes at 2.5 THz, for example, have a footprint that is comparable to a wavelength. Thus, apart from modelling the diodes themselves, the connection with their exciting elements (antennas or microstrip) gives rise to parasitics. Full wave or strictly numeric approaches can be used to account for these parasitics but at the expense of generality of the solution and the CPU time of the calculation. In this paper an equivalent network is derived that accurately accounts for large gap discontinuities (with respect to a wavelength) without suffering from the limitations of available numeric techniques.

Reduced complexity structural modeling for automated airframe synthesis

NASA Technical Reports Server (NTRS)

Hajela, Prabhat

1987-01-01

A procedure is developed for the optimum sizing of wing structures based on representing the built-up finite element assembly of the structure by equivalent beam models. The reduced-order beam models are computationally less demanding in an optimum design environment which dictates repetitive analysis of several trial designs. The design procedure is implemented in a computer program requiring geometry and loading information to create the wing finite element model and its equivalent beam model, and providing a rapid estimate of the optimum weight obtained from a fully stressed design approach applied to the beam. The synthesis procedure is demonstrated for representative conventional-cantilever and joined wing configurations.

Static analysis of rectifier cabinet for nuclear power generating stations based on finite element method

NASA Astrophysics Data System (ADS)

Yin, Qiang; Chen, Tian-jin; Li, Wei-yang; Xiong, Ze-cheng; Ma, Rui

2017-09-01

In order to obtain the deformation map and equivalent stress distribution of rectifier cabinet for nuclear power generating stations, the quality distribution of structure and electrical are described, the tensile bond strengths of the rings are checked, and the finite element model of cabinet is set up by ANSYS. The transport conditions of the hoisting state and fork loading state are analyzed. The deformation map and equivalent stress distribution are obtained. The attentive problems are put forward. It is a reference for analysis method and the obtained results for the transport of rectifier cabinet for nuclear power generating stations.

Equivalent mechanical model of large-amplitude liquid sloshing under time-dependent lateral excitations in low-gravity conditions

NASA Astrophysics Data System (ADS)

Nan, Miao; Junfeng, Li; Tianshu, Wang

2017-01-01

Subjected to external lateral excitations, large-amplitude sloshing may take place in propellant tanks, especially for spacecraft in low-gravity conditions, such as landers in the process of hover and obstacle avoidance during lunar soft landing. Due to lateral force of the order of gravity in magnitude, the amplitude of liquid sloshing becomes too big for the traditional equivalent model to be accurate. Therefore, a new equivalent mechanical model, denominated the "composite model", that can address large-amplitude lateral sloshing in partially filled spherical tanks is established in this paper, with both translational and rotational excitations considered. The hypothesis of liquid equilibrium position following equivalent gravity is first proposed. By decomposing the large-amplitude motion of a liquid into bulk motion following the equivalent gravity and additional small-amplitude sloshing, a better simulation of large-amplitude liquid sloshing is presented. The effectiveness and accuracy of the model are verified by comparing the slosh forces and moments to results of the traditional model and CFD software.

Statistical equivalence and test-retest reliability of delay and probability discounting using real and hypothetical rewards.

PubMed

Matusiewicz, Alexis K; Carter, Anne E; Landes, Reid D; Yi, Richard

2013-11-01

Delay discounting (DD) and probability discounting (PD) refer to the reduction in the subjective value of outcomes as a function of delay and uncertainty, respectively. Elevated measures of discounting are associated with a variety of maladaptive behaviors, and confidence in the validity of these measures is imperative. The present research examined (1) the statistical equivalence of discounting measures when rewards were hypothetical or real, and (2) their 1-week reliability. While previous research has partially explored these issues using the low threshold of nonsignificant difference, the present study fully addressed this issue using the more-compelling threshold of statistical equivalence. DD and PD measures were collected from 28 healthy adults using real and hypothetical $50 rewards during each of two experimental sessions, one week apart. Analyses using area-under-the-curve measures revealed a general pattern of statistical equivalence, indicating equivalence of real/hypothetical conditions as well as 1-week reliability. Exceptions are identified and discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

An Equivalent Circuit of Longitudinal Vibration for a Piezoelectric Structure with Losses.

PubMed

Yuan, Tao; Li, Chaodong; Fan, Pingqing

2018-03-22

Equivalent circuits of piezoelectric structures such as bimorphs and unimorphs conventionally focus on the bending vibration modes. However, the longitudinal vibration modes are rarely considered even though they also play a remarkable role in piezoelectric devices. Losses, especially elastic loss in the metal substrate, are also generally neglected, which leads to discrepancies compared with experiments. In this paper, a novel equivalent circuit with four kinds of losses is proposed for a beamlike piezoelectric structure under the longitudinal vibration mode. This structure consists of a slender beam as the metal substrate, and a piezoelectric patch which covers a partial length of the beam. In this approach, first, complex numbers are used to deal with four kinds of losses-elastic loss in the metal substrate, and piezoelectric, dielectric, and elastic losses in the piezoelectric patch. Next in this approach, based on Mason's model, a new equivalent circuit is developed. Using MATLAB, impedance curves of this structure are simulated by the equivalent circuit method. Experiments are conducted and good agreements are revealed between experiments and equivalent circuit results. It is indicated that the introduction of four losses in an equivalent circuit can increase the result accuracy considerably.

An Equivalent Circuit of Longitudinal Vibration for a Piezoelectric Structure with Losses

PubMed Central

Yuan, Tao; Li, Chaodong; Fan, Pingqing

2018-01-01

Equivalent circuits of piezoelectric structures such as bimorphs and unimorphs conventionally focus on the bending vibration modes. However, the longitudinal vibration modes are rarely considered even though they also play a remarkable role in piezoelectric devices. Losses, especially elastic loss in the metal substrate, are also generally neglected, which leads to discrepancies compared with experiments. In this paper, a novel equivalent circuit with four kinds of losses is proposed for a beamlike piezoelectric structure under the longitudinal vibration mode. This structure consists of a slender beam as the metal substrate, and a piezoelectric patch which covers a partial length of the beam. In this approach, first, complex numbers are used to deal with four kinds of losses—elastic loss in the metal substrate, and piezoelectric, dielectric, and elastic losses in the piezoelectric patch. Next in this approach, based on Mason’s model, a new equivalent circuit is developed. Using MATLAB, impedance curves of this structure are simulated by the equivalent circuit method. Experiments are conducted and good agreements are revealed between experiments and equivalent circuit results. It is indicated that the introduction of four losses in an equivalent circuit can increase the result accuracy considerably. PMID:29565825

Paul Drude's Prediction of Nonreciprocal Mutual Inductance for Tesla Transformers

PubMed Central

McGuyer, Bart

2014-01-01

Inductors, transmission lines, and Tesla transformers have been modeled with lumped-element equivalent circuits for over a century. In a well-known paper from 1904, Paul Drude predicts that the mutual inductance for an unloaded Tesla transformer should be nonreciprocal. This historical curiosity is mostly forgotten today, perhaps because it appears incorrect. However, Drude's prediction is shown to be correct for the conditions treated, demonstrating the importance of constraints in deriving equivalent circuits for distributed systems. The predicted nonreciprocity is not fundamental, but instead is an artifact of the misrepresentation of energy by an equivalent circuit. The application to modern equivalent circuits is discussed. PMID:25542040

Paul Drude's prediction of nonreciprocal mutual inductance for Tesla transformers.

PubMed

McGuyer, Bart

2014-01-01

Inductors, transmission lines, and Tesla transformers have been modeled with lumped-element equivalent circuits for over a century. In a well-known paper from 1904, Paul Drude predicts that the mutual inductance for an unloaded Tesla transformer should be nonreciprocal. This historical curiosity is mostly forgotten today, perhaps because it appears incorrect. However, Drude's prediction is shown to be correct for the conditions treated, demonstrating the importance of constraints in deriving equivalent circuits for distributed systems. The predicted nonreciprocity is not fundamental, but instead is an artifact of the misrepresentation of energy by an equivalent circuit. The application to modern equivalent circuits is discussed.

Iterative methods for elliptic finite element equations on general meshes

NASA Technical Reports Server (NTRS)

Nicolaides, R. A.; Choudhury, Shenaz

1986-01-01

Iterative methods for arbitrary mesh discretizations of elliptic partial differential equations are surveyed. The methods discussed are preconditioned conjugate gradients, algebraic multigrid, deflated conjugate gradients, an element-by-element techniques, and domain decomposition. Computational results are included.

A physics-based model of the electrical impedance of ionic polymer metal composites

NASA Astrophysics Data System (ADS)

Cha, Youngsu; Aureli, Matteo; Porfiri, Maurizio

2012-06-01

In this paper, we analyze the chemoelectrical behavior of ionic polymer metal composites (IPMCs) in the small voltage range with a novel hypothesis on the charge dynamics in proximity of the electrodes. In particular, we homogenize the microscopic properties of the interfacial region through a so-called composite layer which extends between the polymer membrane and the metal electrode. This layer accounts for the dissimilar properties of its constituents by describing the charge distribution via two species of charge carriers, that is, electrons and mobile counterions. We model the charge dynamics in the IPMC by adapting the multiphysics formulation based on the Poisson-Nernst-Planck (PNP) framework, which is enriched through an additional term to capture the electron transport in the composite layer. Under the hypothesis of small voltage input, we use the linearized PNP model to derive an equivalent IPMC circuit model with lumped elements. The equivalent model comprises a resistor connected in series with the parallel of a capacitor and a Warburg impedance element. These elements idealize the phenomena of charge build up in the double layer region and the faradaic impedance related to mass transfer, respectively. We validate the equivalent model through measurements on in-house fabricated samples addressing both IPMC step response and impedance, while assessing the influence of repeated plating cycles on the electrical properties of IPMCs. Experimental results are compared with theoretical findings to identify the equivalent circuit parameters. Findings from this study are compared with alternative impedance models proposed in the literature.

A cis-regulatory sequence driving metabolic insecticide resistance in mosquitoes: functional characterisation and signatures of selection.

PubMed

Wilding, Craig S; Smith, Ian; Lynd, Amy; Yawson, Alexander Egyir; Weetman, David; Paine, Mark J I; Donnelly, Martin J

2012-09-01

Although cytochrome P450 (CYP450) enzymes are frequently up-regulated in mosquitoes resistant to insecticides, no regulatory motifs driving these expression differences with relevance to wild populations have been identified. Transposable elements (TEs) are often enriched upstream of those CYP450s involved in insecticide resistance, leading to the assumption that they contribute regulatory motifs that directly underlie the resistance phenotype. A partial CuRE1 (Culex Repetitive Element 1) transposable element is found directly upstream of CYP9M10, a cytochrome P450 implicated previously in larval resistance to permethrin in the ISOP450 strain of Culex quinquefasciatus, but is absent from the equivalent genomic region of a susceptible strain. Via expression of CYP9M10 in Escherichia coli we have now demonstrated time- and NADPH-dependant permethrin metabolism, prerequisites for confirmation of a role in metabolic resistance, and through qPCR shown that CYP9M10 is >20-fold over-expressed in ISOP450 compared to a susceptible strain. In a fluorescent reporter assay the region upstream of CYP9M10 from ISOP450 drove 10× expression compared to the equivalent region (lacking CuRE1) from the susceptible strain. Close correspondence with the gene expression fold-change implicates the upstream region including CuRE1 as a cis-regulatory element involved in resistance. Only a single CuRE1 bearing allele, identical to the CuRE1 bearing allele in the resistant strain, is found throughout Sub-Saharan Africa, in contrast to the diversity encountered in non-CuRE1 alleles. This suggests a single origin and subsequent spread due to selective advantage. CuRE1 is detectable using a simple diagnostic. When applied to C. quinquefasciatus larvae from Ghana we have demonstrated a significant association with permethrin resistance in multiple field sites (mean Odds Ratio = 3.86) suggesting this marker has relevance to natural populations of vector mosquitoes. However, when CuRE1 was excised from the allele used in the reporter assay through fusion PCR, expression was unaffected, indicating that the TE has no direct role in resistance and hence that CuRE1 is acting only as a marker of an as yet unidentified regulatory motif in the association analysis. This suggests that a re-evaluation of the assumption that TEs contribute regulatory motifs involved in gene expression may be necessary. Copyright © 2012 Elsevier Ltd. All rights reserved.

Optimisation of the imaging and dosimetric characteristics of an electronic portal imaging device employing plastic scintillating fibres using Monte Carlo simulations.

PubMed

Blake, S J; McNamara, A L; Vial, P; Holloway, L; Kuncic, Z

2014-11-21

A Monte Carlo model of a novel electronic portal imaging device (EPID) has been developed using Geant4 and its performance for imaging and dosimetry applications in radiotherapy has been characterised. The EPID geometry is based on a physical prototype under ongoing investigation and comprises an array of plastic scintillating fibres in place of the metal plate/phosphor screen in standard EPIDs. Geometrical and optical transport parameters were varied to investigate their impact on imaging and dosimetry performance. Detection efficiency was most sensitive to variations in fibre length, achieving a peak value of 36% at 50 mm using 400 keV x-rays for the lengths considered. Increases in efficiency for longer fibres were partially offset by reductions in sensitivity. Removing the extra-mural absorber surrounding individual fibres severely decreased the modulation transfer function (MTF), highlighting its importance in maximising spatial resolution. Field size response and relative dose profile simulations demonstrated a water-equivalent dose response and thus the prototype's suitability for dosimetry applications. Element-to-element mismatch between scintillating fibres and underlying photodiode pixels resulted in a reduced MTF for high spatial frequencies and quasi-periodic variations in dose profile response. This effect is eliminated when fibres are precisely matched to underlying pixels. Simulations strongly suggest that with further optimisation, this prototype EPID may be capable of simultaneous imaging and dosimetry in radiotherapy.

Electrothermal Equivalent Three-Dimensional Finite-Element Model of a Single Neuron.

PubMed

Cinelli, Ilaria; Destrade, Michel; Duffy, Maeve; McHugh, Peter

2018-06-01

We propose a novel approach for modelling the interdependence of electrical and mechanical phenomena in nervous cells, by using electrothermal equivalences in finite element (FE) analysis so that existing thermomechanical tools can be applied. First, the equivalence between electrical and thermal properties of the nerve materials is established, and results of a pure heat conduction analysis performed in Abaqus CAE Software 6.13-3 are validated with analytical solutions for a range of steady and transient conditions. This validation includes the definition of equivalent active membrane properties that enable prediction of the action potential. Then, as a step toward fully coupled models, electromechanical coupling is implemented through the definition of equivalent piezoelectric properties of the nerve membrane using the thermal expansion coefficient, enabling prediction of the mechanical response of the nerve to the action potential. Results of the coupled electromechanical model are validated with previously published experimental results of deformation for squid giant axon, crab nerve fibre, and garfish olfactory nerve fibre. A simplified coupled electromechanical modelling approach is established through an electrothermal equivalent FE model of a nervous cell for biomedical applications. One of the key findings is the mechanical characterization of the neural activity in a coupled electromechanical domain, which provides insights into the electromechanical behaviour of nervous cells, such as thinning of the membrane. This is a first step toward modelling three-dimensional electromechanical alteration induced by trauma at nerve bundle, tissue, and organ levels.

Charnockites and granites of the western Adirondacks, New York, USA: a differentiated A-type suite

USGS Publications Warehouse

Whitney, P.R.

1992-01-01

Granitic rocks in the west-central Adirondack Highlands of New York State include both relatively homogeneous charnockitic and hornblende granitic gneisses (CG), that occur in thick stratiform bodies and elliptical domes, and heterogeneous leucogneisses (LG), that commonly are interlayered with metasedimentary rocks. Major- and trace-element geochemical analyses were obtained for 115 samples, including both types of granitoids. Data for CG fail to show the presence of more than one distinct group based on composition. Most of the variance within the CG sample population is consistent with magmatic differentiation combined with incomplete separation of early crystals of alkali feldspar, plagioclase, and pyroxenes or amphibole from the residual liquid. Ti, Fe, Mg, Ca, P, Sr, Ba, and Zr decrease with increasing silica, while Rb and K increase. Within CG, the distinction between charnockitic (orthopyroxene-bearing) and granitic gneisses is correlated with bulk chemistry. The charnockites are consistently more mafic than the hornblende granitic gneisses, although forming a continuum with them. The leucogneisses, while generally more felsic than the charnockites and granitic gneisses, are otherwise geochemically similar to them. The data are consistent with the LG suite being an evolved extrusive equivalent of the intrusive CG suite. Both CG and LG suites are metaluminous to mildly peraluminous and display an A-type geochemical signature, enriched in Fe, K, Ce, Y, Nb, Zr, and Ga and depleted in Ca, Mg, and Sr relative to I- and S-type granites. Rare earth element patterns show moderate LREE enrichment and a negative Eu anomaly throughout the suite. The geochemical data suggest an origin by partial melting of biotite- and plagioclase-rich crustal rocks. Emplacement occurred in an anorogenic or post-collisional tectonic setting, probably at relatively shallow depths. Deformation and granulite-facies metamorphism with some partial melting followed during the Ottawan phase of the Grenville Orogeny, yielding the present migmatitic granitic and charnockitic gneisses. ?? 1992.

The Short Form 36 English and Chinese versions were equivalent in a multiethnic Asian population.

PubMed

Tan, Maudrene L S; Wee, Hwee-Lin; Lee, Jeannette; Ma, Stefan; Heng, Derrick; Tai, E-Shyong; Thumboo, Julian

2013-07-01

The primary aim of this article was to evaluate measurement equivalence of the English and Chinese versions of the Short Form 36 version 2 (SF-36v2) and Short Form 6D (SF-6D). In this cross-sectional study, health-related quality of life (HRQoL) was measured from 4,973 ethnic Chinese subjects using the SF-36v2 questionnaire. Measurement equivalence of domain and utility scores for the English- and Chinese-language SF-36v2 and SF-6D were assessed by examining the score differences between the two languages using linear regression models, with and without adjustment for known determinants of HRQoL. Equivalence was achieved if the 90% confidence interval (CI) of the differences in scores, due to language, fell within a predefined equivalence margin. Compared with English-speaking Chinese, Chinese-speaking Chinese were significantly older (47.6 vs. 55.5 years). All SF-36v2 domains were equivalent after adjusting for known HRQoL. SF-6D utility/items had the 90% CI either fully or partially overlap their predefined equivalence margin. The English- and Chinese-language versions of the SF-36v2 and SF-6D demonstrated equivalence. Copyright © 2013 Elsevier Inc. All rights reserved.

Theoretical Studies of Microstrip Antennas : Volume I, General Design Techniques and Analyses of Single and Coupled Elements

DOT National Transportation Integrated Search

1979-09-01

Volume 1 of Theoretical Studies of Microstrip Antennas deals with general techniques and analyses of single and coupled radiating elements. Specifically, we review and then employ an important equivalence theorem that allows a pair of vector potentia...

Evolution of the Campanian Ignimbrite Magmatic System II: Trace Element and Th Isotopic Evidence for Open-System Processes

NASA Astrophysics Data System (ADS)

Bohrson, W. A.; Spera, F. J.; Fowler, S.; Belkin, H.; de Vivo, B.

2005-12-01

The Campanian Ignimbrite, a large volume (~200 km3 DRE) trachytic to phonolitic ignimbrite was deposited at ~39.3 ka and represents the largest of a number of highly explosive volcanic events in the region near Naples, Italy. Thermodynamic modeling of the major element evolution using the MELTS algorithm (see companion contribution by Fowler et al.) provides detailed information about the identity of and changes in proportions of solids along the liquid line of descent during isobaric fractional crystallization. We have derived trace element mass balance equations that explicitly accommodate changing mineral-melt bulk distribution coefficients during crystallization and also simultaneously satisfy energy and major element mass conservation. Although major element patterns are reasonably modeled assuming closed system fractional crystallization, modeling of trace elements that represent a range of behaviors (e.g. Zr, Nb, Th, U, Rb, Sm, Sr) yields trends for closed system fractionation that are distinct from those observed. These results suggest open-system processes were also important in the evolution of the Campanian magmatic system. Th isotope data yield an apparent isochron that is ~20 kyr younger than the age of the deposit, and age-corrected Th isotope data indicate that the magma body was an open-system at the time of eruption. Because open-system processes can profoundly change isotopic characteristics of a magma body, these results illustrate that it is critical to understand the contribution that open-system processes make to silicic magma bodies prior to assigning relevance to age or timescale information derived from isotope systematics. Fluid-magma interaction has been proposed as a mechanism to change isotopic and elemental characteristics of magma bodies, but an evaluation of the mass and thermal constraints on such a process suggest large-scale fluid-melt interaction at liquidus temperatures is unlikely. In the case of the magma body associated with the Campanian Ignimbrite, the most likely source of open-system signatures is assimilation of partial melts of compositionally heterogeneous basement composed of older cumulates and intrusive equivalents of volcanic activity within the Campanian region. Additional trace element modeling, explicitly evaluating the mass and energy balance effects that fluid, solids, and melt have on trace element evolution, will further elucidate the contributions of open vs. closed system processes within the Campanian magma body.

Development of flexible rotor balancing criteria

NASA Technical Reports Server (NTRS)

Walter, W. W.; Rieger, N. F.

1979-01-01

Several studies in which analytical procedures were used to obtain balancing criteria for flexible rotors are described. General response data for a uniform rotor in damped flexible supports were first obtained for plain cylindrical bearings, tilting pad bearings, axial groove bearings, and partial arc bearings. These data formed the basis for the flexible rotor balance criteria presented. A procedure by which a practical rotor in bearings could be reduced to an equivalent uniform rotor was developed and tested. It was found that the equivalent rotor response always exceeded to practical rotor response by more than sixty percent for the cases tested. The equivalent rotor procedure was then tested against six practical rotor configurations for which data was available. It was found that the equivalent rotor method offered a procedure by which balance criteria could be selected for practical flexible rotors, using the charts given for the uniform rotor.

Effects of Fuel Distribution on Detonation Tube Performance

NASA Technical Reports Server (NTRS)

Perkins, H. Douglas; Sung, Chih-Jen

2003-01-01

A pulse detonation engine uses a series of high frequency intermittent detonation tubes to generate thrust. The process of filling the detonation tube with fuel and air for each cycle may yield non-uniform mixtures. Uniform mixing is commonly assumed when calculating detonation tube thrust performance. In this study, detonation cycles featuring idealized non-uniform Hz/air mixtures were analyzed using a two-dimensional Navier-Stokes computational fluid dynamics code with detailed chemistry. Mixture non-uniformities examined included axial equivalence ratio gradients, transverse equivalence ratio gradients, and partially fueled tubes. Three different average test section equivalence ratios were studied; one stoichiometric, one fuel lean, and one fuel rich. All mixtures were detonable throughout the detonation tube. Various mixtures representing the same average test section equivalence ratio were shown to have specific impulses within 1% of each other, indicating that good fuel/air mixing is not a prerequisite for optimal detonation tube performance under conditions investigated.

Development of an Algorithm for Automatic Analysis of the Impedance Spectrum Based on a Measurement Model

NASA Astrophysics Data System (ADS)

Kobayashi, Kiyoshi; Suzuki, Tohru S.

2018-03-01

A new algorithm for the automatic estimation of an equivalent circuit and the subsequent parameter optimization is developed by combining the data-mining concept and complex least-squares method. In this algorithm, the program generates an initial equivalent-circuit model based on the sampling data and then attempts to optimize the parameters. The basic hypothesis is that the measured impedance spectrum can be reproduced by the sum of the partial-impedance spectra presented by the resistor, inductor, resistor connected in parallel to a capacitor, and resistor connected in parallel to an inductor. The adequacy of the model is determined by using a simple artificial-intelligence function, which is applied to the output function of the Levenberg-Marquardt module. From the iteration of model modifications, the program finds an adequate equivalent-circuit model without any user input to the equivalent-circuit model.

Artificial Neural Networks Equivalent to Fuzzy Algebra T-Norm Conjunction Operators

NASA Astrophysics Data System (ADS)

Iliadis, L. S.; Spartalis, S. I.

2007-12-01

This paper describes the construction of three Artificial Neural Networks with fuzzy input and output, imitating the performance of fuzzy algebra conjunction operators. More specifically, it is applied over the results of a previous research effort that used T-Norms in order to produce a characteristic torrential risk index that unified the partial risk indices for the area of Xanthi. Each one of the three networks substitutes a T-Norm and consequently they can be used as equivalent operators. This means that ANN performing Fuzzy Algebra operations can be designed and developed.

Can the Isolated-Elements Strategy Be Improved by Targeting Points of High Cognitive Load for Additional Practice?

ERIC Educational Resources Information Center

Ayres, Paul

2013-01-01

Reducing problem complexity by isolating elements has been shown to be an effective instructional strategy. Novices, in particular, benefit from learning from worked examples that contain partially interacting elements rather than worked examples that provide full interacting elements. This study investigated whether the isolating-elements…

Matrix multiplication operations using pair-wise load and splat operations

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

Eichenberger, Alexandre E.; Gschwind, Michael K.; Gunnels, John A.

Mechanisms for performing a matrix multiplication operation are provided. A vector load operation is performed to load a first vector operand of the matrix multiplication operation to a first target vector register. A pair-wise load and splat operation is performed to load a pair of scalar values of a second vector operand and replicate the pair of scalar values within a second target vector register. An operation is performed on elements of the first target vector register and elements of the second target vector register to generate a partial product of the matrix multiplication operation. The partial product is accumulatedmore » with other partial products and a resulting accumulated partial product is stored. This operation may be repeated for a second pair of scalar values of the second vector operand.« less

Big bang photosynthesis and pregalactic nucleosynthesis of light elements

NASA Technical Reports Server (NTRS)

Audouze, J.; Lindley, D.; Silk, J.

1985-01-01

Two nonstandard scenarios for pregalactic synthesis of the light elements (H-2, He-3, He-4, and Li-7) are developed. Big bang photosynthesis occurs if energetic photons, produced by the decay of massive neutrinos or gravitinos, partially photodisintegrate He-4 (formed in the standard hot big bang) to produce H-2 and He-3. In this case, primordial nucleosynthesis no longer constrains the baryon density of the universe, or the number of neutrino species. Alternatively, one may dispense partially or completely with the hot big bang and produce the light elements by bombardment of primordial gas, provided that He-4 is synthesized by a later generation of massive stars.

Simulated response of a multi-element thick gas electron multiplier-based microdosimeter to high energy neutrons.

PubMed

Moslehi, Amir; Raisali, Gholamreza

2018-07-01

The response of a microdosimeter for neutrons above 14 MeV is investigated. The mean quality factors and dose-equivalents are determined using lineal energy distributions calculated by Monte Carlo simulations (Geant4 toolkit). From 14 MeV to 5 GeV, the mean quality factors were found to vary between 6.00 and 9.30 and the dose-equivalents were in agreement with the true ambient dose-equivalent at the depth of 10 mm inside the ICRU sphere, H * (10). An energy-independent dose-equivalent response around a median value of 0.86 within 22% uncertainty was obtained. Therefore, the microdosimeter is appropriate for dose-equivalent measurement of high-energy neutrons. Copyright © 2018 Elsevier Ltd. All rights reserved.

Compilation of Pilot Cognitive Ability Norms

DTIC Science & Technology

2011-12-01

2.1.1 Change in Performance Method. The first method is a pretest , posttest paradigm. It is the most reliable but requires prior, premorbid...elements of the person’s own performance to make conclusions regarding cognitive change. A common approach uses the effects of aging on various types of...Percentile Equivalence for IQ Scores on the MAB-II ............................................... 7 4 Percentile Equivalence for Verbal Subtest

Equivalence between short-time biphasic and incompressible elastic material responses.

PubMed

Ateshian, Gerard A; Ellis, Benjamin J; Weiss, Jeffrey A

2007-06-01

Porous-permeable tissues have often been modeled using porous media theories such as the biphasic theory. This study examines the equivalence of the short-time biphasic and incompressible elastic responses for arbitrary deformations and constitutive relations from first principles. This equivalence is illustrated in problems of unconfined compression of a disk, and of articular contact under finite deformation, using two different constitutive relations for the solid matrix of cartilage, one of which accounts for the large disparity observed between the tensile and compressive moduli in this tissue. Demonstrating this equivalence under general conditions provides a rationale for using available finite element codes for incompressible elastic materials as a practical substitute for biphasic analyses, so long as only the short-time biphasic response is sought. In practice, an incompressible elastic analysis is representative of a biphasic analysis over the short-term response deltat

Peridynamic Multiscale Finite Element Methods

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

Costa, Timothy; Bond, Stephen D.; Littlewood, David John

The problem of computing quantum-accurate design-scale solutions to mechanics problems is rich with applications and serves as the background to modern multiscale science research. The prob- lem can be broken into component problems comprised of communicating across adjacent scales, which when strung together create a pipeline for information to travel from quantum scales to design scales. Traditionally, this involves connections between a) quantum electronic structure calculations and molecular dynamics and between b) molecular dynamics and local partial differ- ential equation models at the design scale. The second step, b), is particularly challenging since the appropriate scales of molecular dynamic andmore » local partial differential equation models do not overlap. The peridynamic model for continuum mechanics provides an advantage in this endeavor, as the basic equations of peridynamics are valid at a wide range of scales limiting from the classical partial differential equation models valid at the design scale to the scale of molecular dynamics. In this work we focus on the development of multiscale finite element methods for the peridynamic model, in an effort to create a mathematically consistent channel for microscale information to travel from the upper limits of the molecular dynamics scale to the design scale. In particular, we first develop a Nonlocal Multiscale Finite Element Method which solves the peridynamic model at multiple scales to include microscale information at the coarse-scale. We then consider a method that solves a fine-scale peridynamic model to build element-support basis functions for a coarse- scale local partial differential equation model, called the Mixed Locality Multiscale Finite Element Method. Given decades of research and development into finite element codes for the local partial differential equation models of continuum mechanics there is a strong desire to couple local and nonlocal models to leverage the speed and state of the art of local models with the flexibility and accuracy of the nonlocal peridynamic model. In the mixed locality method this coupling occurs across scales, so that the nonlocal model can be used to communicate material heterogeneity at scales inappropriate to local partial differential equation models. Additionally, the computational burden of the weak form of the peridynamic model is reduced dramatically by only requiring that the model be solved on local patches of the simulation domain which may be computed in parallel, taking advantage of the heterogeneous nature of next generation computing platforms. Addition- ally, we present a novel Galerkin framework, the 'Ambulant Galerkin Method', which represents a first step towards a unified mathematical analysis of local and nonlocal multiscale finite element methods, and whose future extension will allow the analysis of multiscale finite element methods that mix models across scales under certain assumptions of the consistency of those models.« less

9 CFR 381.150 - Requirements for the production of fully cooked poultry products and partially cooked poultry...

Code of Federal Regulations, 2011 CFR

2011-01-01

... standards: (1) Lethality. A 7-log10 reduction of Salmonella or an alternative lethality that achieves an equivalent probability that no viable Salmonella organisms remain in the finished product, as well as the...

Na, K, Rb, and Cs Exchange in Heulandite Single-Crystals: X-Ray Structure Refinements at 100 K

NASA Astrophysics Data System (ADS)

Yang, Ping; Armbruster, Thomas

1996-04-01

The crystal structures of Na-, K-, Rb-, and Cs-exchanged varieties of the zeolite heulandite with the simplified compositionM+9Al9Si27O72·nH2O were studied by single-crystal X-ray diffraction at 100 K. The structure refinements of Na-, K-, and Rb-exchanged heulandite were performed in space groupC2/mwith resultantRvalues of 3.8, 3.0, and 4.9%, respectively. Cs-exchanged heulandite was refined in space groupC[formula], yielding anRvalue of 3.4%. X-ray single-crystal data of the Cs-exchanged variety indicated that many reflections of typeh k lwere not equivalent toh -k las expected for monoclinic symmetry. With increasing radius of the incorporated channel cations, thebaxis increases from 17.93 to 18.09 Å leading to a slight widening of the channels. The number of H2O molecules also decreases with increasing cation radius due to space limitations. Three general cation positions (II-1,C3, andB4) were found in the four exchanged heulandite samples. For Rb- and Cs-exchanged crystals, the additional cation siteA2 occurs. In Cs-exchanged heulandite symmetry lowering is due to partial Si, Al ordering in the framework accompanied with a more asymmetric arrangement of channel Cs. Only if heavy elements in the channels are present the symmetry information of the framework is enforced, thus partial Si, Al ordering can be resolved.

Thermal research of infrared sight thermoelectric cooler control circuit under temperature environment

NASA Astrophysics Data System (ADS)

Gao, Youtang; Ding, Huan; Xue, Xiao; Xu, Yuan; Chang, Benkang

2010-10-01

Testing device TST-05B, which is suitable for adaptability test of semiconductor devices, electronic products and other military equipment under the condition of the surrounding air temperature rapidly changing, is used here for temperature shock test.Thermal stability technology of thermoelectric cooler control circuit infrared sight under temperature shock is studied in this paper. Model parameters and geometry is configured for ADI devices (ADN8830), welding material and PCB which are used in system. Thermoelectric cooler control circuit packaged by CSP32 distribution are simulated and analyzed by thermal shock and waveform through engineering finite element analysis software ANSYYS. Because solders of the whole model have much stronger stress along X direction than that of other directions, initial stress constraints along X direction are primarily considered when the partial model of single solder is imposed by thermal load. When absolute thermal loads stresses of diagonal nodes with maximum strains are separated from the whole model, interpolation is processed according to thermal loads circulation. Plastic strains and thermal stresses of nodes in both sides of partial model are obtained. The analysis results indicates that with thermal load circulation, maximum forces of each circulation along X direction are increasingly enlarged and with the accumulation of plastic strains of danger point, at the same time structural deformation and the location of maximum equivalent plastic strain in the solder joints at the first and eighth, the composition will become invalid in the end.

A modified moment-fitted integration scheme for X-FEM applications with history-dependent material data

NASA Astrophysics Data System (ADS)

Zhang, Ziyu; Jiang, Wen; Dolbow, John E.; Spencer, Benjamin W.

2018-01-01

We present a strategy for the numerical integration of partial elements with the eXtended finite element method (X-FEM). The new strategy is specifically designed for problems with propagating cracks through a bulk material that exhibits inelasticity. Following a standard approach with the X-FEM, as the crack propagates new partial elements are created. We examine quadrature rules that have sufficient accuracy to calculate stiffness matrices regardless of the orientation of the crack with respect to the element. This permits the number of integration points within elements to remain constant as a crack propagates, and for state data to be easily transferred between successive discretizations. In order to maintain weights that are strictly positive, we propose an approach that blends moment-fitted weights with volume-fraction based weights. To demonstrate the efficacy of this simple approach, we present results from numerical tests and examples with both elastic and plastic material response.

Effective implementation of the weak Galerkin finite element methods for the biharmonic equation

DOE PAGES

Mu, Lin; Wang, Junping; Ye, Xiu

2017-07-06

The weak Galerkin (WG) methods have been introduced in [11, 12, 17] for solving the biharmonic equation. The purpose of this paper is to develop an algorithm to implement the WG methods effectively. This can be achieved by eliminating local unknowns to obtain a global system with significant reduction of size. In fact this reduced global system is equivalent to the Schur complements of the WG methods. The unknowns of the Schur complement of the WG method are those defined on the element boundaries. The equivalence of theWG method and its Schur complement is established. The numerical results demonstrate themore » effectiveness of this new implementation technique.« less

Effective implementation of the weak Galerkin finite element methods for the biharmonic equation

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

Mu, Lin; Wang, Junping; Ye, Xiu

The weak Galerkin (WG) methods have been introduced in [11, 12, 17] for solving the biharmonic equation. The purpose of this paper is to develop an algorithm to implement the WG methods effectively. This can be achieved by eliminating local unknowns to obtain a global system with significant reduction of size. In fact this reduced global system is equivalent to the Schur complements of the WG methods. The unknowns of the Schur complement of the WG method are those defined on the element boundaries. The equivalence of theWG method and its Schur complement is established. The numerical results demonstrate themore » effectiveness of this new implementation technique.« less

A posteriori error estimation for multi-stage Runge–Kutta IMEX schemes

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

Chaudhry, Jehanzeb H.; Collins, J. B.; Shadid, John N.

Implicit–Explicit (IMEX) schemes are widely used for time integration methods for approximating solutions to a large class of problems. In this work, we develop accurate a posteriori error estimates of a quantity-of-interest for approximations obtained from multi-stage IMEX schemes. This is done by first defining a finite element method that is nodally equivalent to an IMEX scheme, then using typical methods for adjoint-based error estimation. Furthermore, the use of a nodally equivalent finite element method allows a decomposition of the error into multiple components, each describing the effect of a different portion of the method on the total error inmore » a quantity-of-interest.« less

A posteriori error estimation for multi-stage Runge–Kutta IMEX schemes

DOE PAGES

Chaudhry, Jehanzeb H.; Collins, J. B.; Shadid, John N.

2017-02-05

Implicit–Explicit (IMEX) schemes are widely used for time integration methods for approximating solutions to a large class of problems. In this work, we develop accurate a posteriori error estimates of a quantity-of-interest for approximations obtained from multi-stage IMEX schemes. This is done by first defining a finite element method that is nodally equivalent to an IMEX scheme, then using typical methods for adjoint-based error estimation. Furthermore, the use of a nodally equivalent finite element method allows a decomposition of the error into multiple components, each describing the effect of a different portion of the method on the total error inmore » a quantity-of-interest.« less

Modification of a Macromechanical Finite-Element Based Model for Impact Analysis of Triaxially-Braided Composites

NASA Technical Reports Server (NTRS)

Goldberg, Robert K.; Blinzler, Brina J.; Binienda, Wieslaw K.

2010-01-01

A macro level finite element-based model has been developed to simulate the mechanical and impact response of triaxially-braided polymer matrix composites. In the analytical model, the triaxial braid architecture is simulated by using four parallel shell elements, each of which is modeled as a laminated composite. For the current analytical approach, each shell element is considered to be a smeared homogeneous material. The commercial transient dynamic finite element code LS-DYNA is used to conduct the simulations, and a continuum damage mechanics model internal to LS-DYNA is used as the material constitutive model. The constitutive model requires stiffness and strength properties of an equivalent unidirectional composite. Simplified micromechanics methods are used to determine the equivalent stiffness properties, and results from coupon level tests on the braided composite are utilized to back out the required strength properties. Simulations of quasi-static coupon tests of several representative braided composites are conducted to demonstrate the correlation of the model. Impact simulations of a represented braided composites are conducted to demonstrate the capability of the model to predict the penetration velocity and damage patterns obtained experimentally.

Beam hardening and partial beam hardening of the bowtie filter: Effects on dosimetric applications in CT

NASA Astrophysics Data System (ADS)

Lopez-Rendon, X.; Zhang, G.; Bosmans, H.; Oyen, R.; Zanca, F.

2014-03-01

Purpose: To estimate the consequences on dosimetric applications when a CT bowtie filter is modeled by means of full beam hardening versus partial beam hardening. Method: A model of source and filtration for a CT scanner as developed by Turner et. al. [1] was implemented. Specific exposures were measured with the stationary CT X-ray tube in order to assess the equivalent thickness of Al of the bowtie filter as a function of the fan angle. Using these thicknesses, the primary beam attenuation factors were calculated from the energy dependent photon mass attenuation coefficients and used to include beam hardening in the spectrum. This was compared to a potentially less computationally intensive approach, which accounts only partially for beam hardening, by giving the photon spectrum a global (energy independent) fan angle specific weighting factor. Percentage differences between the two methods were quantified by calculating the dose in air after passing several water equivalent thicknesses representative for patients having different BMI. Specifically, the maximum water equivalent thickness of the lateral and anterior-posterior dimension and of the corresponding (half) effective diameter were assessed. Results: The largest percentage differences were found for the thickest part of the bowtie filter and they increased with patient size. For a normal size patient they ranged from 5.5% at half effective diameter to 16.1% for the lateral dimension; for the most obese patient they ranged from 7.7% to 19.3%, respectively. For a complete simulation of one rotation of the x-ray tube, the proposed method was 12% faster than the complete simulation of the bowtie filter. Conclusion: The need for simulating the beam hardening of the bow tie filter in Monte Carlo platforms for CT dosimetry will depend on the required accuracy.

Interpretation of trace element and isotope features of basalts: relevance of field relations, petrology, major element data, phase equilibria, and magma chamber modeling in basalt petrogenesis

NASA Astrophysics Data System (ADS)

O'Hara, M. J.; Herzberg, C.

2002-06-01

The concentrations and ratios of the major elements determine the physical properties and the phase equilibria behavior of peridotites and basalts in response to the changing energy contents of the systems. The behavior of the trace elements and isotopic features are influenced in their turn by the phase equilibria, by the physical character of the partial melting and partial crystallization processes, and by the way in which a magma interacts with its wall rocks. Concentrating on the trace element and isotope contents of basalts to the exclusion of the field relations, petrology, major element data, and phase equilibria is as improvident as slaughtering the buffalo for the sake of its tongue. The crust is a cool boundary layer and a density filter, which impedes the upward transfer of hot, dense "primary" picritic and komatiitic liquids. Planetary crusts are sites of large-scale contamination and extensive partial crystallization of primitive melts striving to escape to the surface. Escape of truly unmodified primitive melts to the surface is a rare event, requiring the resolution of daunting problems in chemical and mechanical engineering. Primary status for volumetrically abundant basalts such as mid-ocean ridge basalt, ocean island basalt, and continental flood basalts is denied by their low-pressure cotectic character, first remarked upon on petrological grounds in 1928 and on experimental grounds in 1962. These basalt liquids are products of crystal-liquid separation at low pressure. Primary status for these common basalts is further denied by the phase equilibria of such compositions at elevated pressures, when the required residual mantle mineralogy (magnesian olivine and orthopyroxene) is not stable at the liquidus. It is also denied by the picritic or komatiitic nature of partial melts of candidate upper-mantle compositions at high pressures - a conclusion supported by calculation of the melt composition, which would need to be extracted in order to explain the chemical variation between fertile and residual peridotite in natural ultramafic rock suites. The subtleties of magma chamber partial crystallization processes can produce an astounding array of "pseudospidergrams," a small selection of which have been explored here. Major modification of the trace element geochemistry and trace element ratios, even those of the highly incompatible elements, must always be entertained whenever the evidence suggests the possibility of partial crystallization. At one extreme, periodically recharged, periodically tapped magma chambers might undergo partial crystallization by ˜95% consolidation of a succession of small packets of the magma. Refluxing of the 5% residual melts from such a process into the main body of melt would lead to eventual discrimination between highly incompatible elements in that residual liquid comparable with that otherwise achieved by 0.1 to 0.3% liquid extraction in equilibrium partial melting. Great caution needs to be exercised in attempting the reconstruction of more primitive compositions by addition of troctolite, gabbro, and olivine to apparently primitive lava compositions. Special attention is focussed on the phase equilibria involving olivine, plagioclase (i.e., troctolite), and liquid because a high proportion of erupted basalts carry these two phases as phenocrysts, yet the equilibria are restricted to crustal pressures and are only encountered by wide ranges of basaltic compositions at pressures less than 0.5 GPa. The mere presence of plagioclase phenocrysts may be sufficient to disqualify candidate primitive magmas. Determination of the actual contributions of crustal processes to petrogenesis requires a return to detailed field, experimental, and forensic petrologic studies of individual erupted basalt flows; of a multitude of cumulate gabbros and their contacts; and of upper-mantle outcrops.

Three-dimensional finite element analysis of implant-assisted removable partial dentures.

PubMed

Eom, Ju-Won; Lim, Young-Jun; Kim, Myung-Joo; Kwon, Ho-Beom

2017-06-01

Whether the implant abutment in implant-assisted removable partial dentures (IARPDs) functions as a natural removable partial denture (RPD) tooth abutment is unknown. The purpose of this 3-dimensional finite element study was to analyze the biomechanical behavior of implant crown, bone, RPD, and IARPD. Finite element models of the partial maxilla, teeth, and prostheses were generated on the basis of a patient's computed tomographic data. The teeth, surveyed crowns, and RPDs were created in the model. With the generated components, four 3-dimensional finite element models of the partial maxilla were constructed: tooth-supported RPD (TB), implant-supported RPD (IB), tooth-tissue-supported RPD (TT), and implant-tissue-supported RPD (IT) models. Oblique loading of 300 N was applied on the crowns and denture teeth. The von Mises stress and displacement of the denture abutment tooth and implant system were identified. The highest von Mises stress values of both IARPDs occurred on the implants, while those of both natural tooth RPDs occurred on the frameworks of the RPDs. The highest von Mises stress of model IT was about twice that of model IB, while the value of model TT was similar to that of model TB. The maximum displacement was greater in models TB and TT than in models IB and IT. Among the 4 models, the highest maximum displacement value was observed in the model TT and the lowest value was in the model IB. Finite element analysis revealed that the stress distribution pattern of the IARPDs was different from that of the natural tooth RPDs and the stress distribution of implant-supported RPD was different from that of implant-tissue-supported RPD. When implants are used for RPD abutments, more consideration concerning the RPD design and the number or location of the implant is necessary. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

An entropy stable nodal discontinuous Galerkin method for the two dimensional shallow water equations on unstructured curvilinear meshes with discontinuous bathymetry

NASA Astrophysics Data System (ADS)

Wintermeyer, Niklas; Winters, Andrew R.; Gassner, Gregor J.; Kopriva, David A.

2017-07-01

We design an arbitrary high-order accurate nodal discontinuous Galerkin spectral element approximation for the non-linear two dimensional shallow water equations with non-constant, possibly discontinuous, bathymetry on unstructured, possibly curved, quadrilateral meshes. The scheme is derived from an equivalent flux differencing formulation of the split form of the equations. We prove that this discretization exactly preserves the local mass and momentum. Furthermore, combined with a special numerical interface flux function, the method exactly preserves the mathematical entropy, which is the total energy for the shallow water equations. By adding a specific form of interface dissipation to the baseline entropy conserving scheme we create a provably entropy stable scheme. That is, the numerical scheme discretely satisfies the second law of thermodynamics. Finally, with a particular discretization of the bathymetry source term we prove that the numerical approximation is well-balanced. We provide numerical examples that verify the theoretical findings and furthermore provide an application of the scheme for a partial break of a curved dam test problem.

[Carbon monoxide tests in a steady state. Uptake and transfer capacity, normal values and lower limits].

PubMed

Ramonatxo, M; Préfaut, C; Guerrero, H; Moutou, H; Bansard, X; Chardon, G

1982-01-01

The aim of this study was to establish data which would best demonstrate the variations of different tests using Carbon Monoxide as a tracer gas (total and partial functional uptake coefficient and transfer capacity) to establish mean values and lower limits of normal of these tests. Multivariate statistical analysis was used; in the first stage a connection was sought between the fractional uptake coefficient (partial and total) to other parameters, comparing subjects and data. In the second stage the comparison was refined by eliminating the least useful data, trying, despite a small loss of material, to reveal the most important connections, linear or otherwise. The fractional uptake coefficients varied according to sex, also the variation of the partial alveolar-expired fractional uptake equivalent (DuACO) was largely a function of respiratory rate and tidal volume. The alveolar-arterial partial fractional uptake equivalent (DuaCO) depended more on respiratory frequency and age. Finally the total fractional uptake coefficient (DuCO) and the transfer capacity corrected per liter of ventilation (TLCO/V) were functions of these parameters. The last stage of this work, after taking account of the statistical observations consistent with the facts of these physiological hypotheses led to a search for a better way of approaching the laws linking the collected data to the fractional uptake coefficient. The lower limits of normal were arbitrarily defined, separating those 5% of subjects deviating most strongly from the mean. As a result, the relationship between the lower limit of normal and the theoretical mean value was 90% for the partial and total fractional uptake coefficient and 70% for the transfer capacity corrected per liter of ventilation.

Determination of naturally radioactive elements in chalk sticks by means of gamma spectroscopy

NASA Astrophysics Data System (ADS)

Abd El-Wahab, Magda; Morsy, Zeinab; El-Faramawy, Nabil

2010-04-01

The radiation hazards due to ingestion of chalkboard dust were investigated. Sixteen samples from three different origin fabricates were used. The estimation of radiation hazard indices were based on the evaluation of the concentration activities of the natural radionuclides 238U, 232Th and 40K. The radium equivalent activity, external hazard index, internal hazard index and the annual dose equivalent associated with the radionuclides were calculated and compared with international recommended values to assess the radiation hazard. The values of internal and external radiation hazard indices were found to be less than unity. The annual effective dose rate obtained, E eff, and the annual gonadal dose equivalent (AGDE) are found to be less than the limit of the doses recommended by the International Commission on Radiological Protection for the general public. The analytical results show that besides the main calcium content, some toxic elements, S, Mo and Pb and Ni and Pb, in the Egyptian and imported chalk stocks, respectively, existed.

Determination of naturally radioactive elements in chalk sticks by means of gamma spectroscopy

NASA Astrophysics Data System (ADS)

El-Wahab, Magda Abd; Morsy, Zeinab; El-Faramawy, Nabil

The radiation hazards due to ingestion of chalkboard dust were investigated. Sixteen samples from three different origin fabricates were used. The estimation of radiation hazard indices were based on the evaluation of the concentration activities of the natural radionuclides 238U, 232Th and 40K. The radium equivalent activity, external hazard index, internal hazard index and the annual dose equivalent associated with the radionuclides were calculated and compared with international recommended values to assess the radiation hazard. The values of internal and external radiation hazard indices were found to be less than unity. The annual effective dose rate obtained, Eeff, and the annual gonadal dose equivalent (AGDE) are found to be less than the limit of the doses recommended by the International Commission on Radiological Protection for the general public. The analytical results show that besides the main calcium content, some toxic elements, S, Mo and Pb and Ni and Pb, in the Egyptian and imported chalk stocks, respectively, existed.

Elemental abundance analyses with DAO spectrograms. VII - The late normal B stars Pi Ceti, 134 Tauri, 21 Aquilae, and Nu Capricorni and the use of RETICON spectra

NASA Astrophysics Data System (ADS)

Adelman, Saul J.

1991-09-01

This paper presents elemental abundance analyses of sharp-lined normal late B stars. These stars exhibit mostly near-solar abundances, but each star also shows a few abundances which are a factor of 2 less than solar. The coadded photographic spectrograms are supplemented with Reticon data. A comparison of 261 equivalent widths on 2.4 A/mm spectra of sharp-lined B and A stars shows that the Reticon equivalent widths are about 95 percent of the coadded equivalent mean. The H-gamma profiles of the coadded and Reticon spectra for eight sharp-lined stars show generally good agreement. The generally high quality of the coadded data produced from 10 or more spectrograms is confirmed using the REDUCE graphics-oriented computed reduction code. For five stars, metal lines which fall in the gap between the U and V plates are analyzed using Reticon data.

Elemental abundance analyses with DAO spectrograms. VII - The late normal B stars Pi Ceti, 134 Tauri, 21 Aquilae, and Nu Capricorni and the use of Reticon spectra

NASA Technical Reports Server (NTRS)

Adelman, Saul J.

1991-01-01

This paper presents elemental abundance analyses of sharp-lined normal late B stars. These stars exhibit mostly near-solar abundances, but each star also shows a few abundances which are a factor of 2 less than solar. The coadded photographic spectrograms are supplemented with Reticon data. A comparison of 261 equivalent widths on 2.4 A/mm spectra of sharp-lined B and A stars shows that the Reticon equivalent widths are about 95 percent of the coadded equivalent mean. The H-gamma profiles of the coadded and Reticon spectra for eight sharp-lined stars show generally good agreement. The generally high quality of the coadded data produced from 10 or more spectrograms is confirmed using the REDUCE graphics-oriented computed reduction code. For five stars, metal lines which fall in the gap between the U and V plates are analyzed using Reticon data.

Chemiluminescence-based multivariate sensing of local equivalence ratios in premixed atmospheric methane-air flames

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

Tripathi, Markandey M.; Krishnan, Sundar R.; Srinivasan, Kalyan K.

Chemiluminescence emissions from OH*, CH*, C2, and CO2 formed within the reaction zone of premixed flames depend upon the fuel-air equivalence ratio in the burning mixture. In the present paper, a new partial least square regression (PLS-R) based multivariate sensing methodology is investigated and compared with an OH*/CH* intensity ratio-based calibration model for sensing equivalence ratio in atmospheric methane-air premixed flames. Five replications of spectral data at nine different equivalence ratios ranging from 0.73 to 1.48 were used in the calibration of both models. During model development, the PLS-R model was initially validated with the calibration data set using themore » leave-one-out cross validation technique. Since the PLS-R model used the entire raw spectral intensities, it did not need the nonlinear background subtraction of CO2 emission that is required for typical OH*/CH* intensity ratio calibrations. An unbiased spectral data set (not used in the PLS-R model development), for 28 different equivalence ratio conditions ranging from 0.71 to 1.67, was used to predict equivalence ratios using the PLS-R and the intensity ratio calibration models. It was found that the equivalence ratios predicted with the PLS-R based multivariate calibration model matched the experimentally measured equivalence ratios within 7%; whereas, the OH*/CH* intensity ratio calibration grossly underpredicted equivalence ratios in comparison to measured equivalence ratios, especially under rich conditions ( > 1.2). The practical implications of the chemiluminescence-based multivariate equivalence ratio sensing methodology are also discussed.« less

Infiltration behaviour of elemental mercury DNAPL in fully and partially water saturated porous media

NASA Astrophysics Data System (ADS)

D'Aniello, Andrea; Hartog, Niels; Sweijen, Thomas; Pianese, Domenico

2018-02-01

Mercury is a contaminant of global concern due to its harmful effects on human health and for the detrimental consequences of its release in the environment. Sources of liquid elemental mercury are usually anthropogenic, such as chlor-alkali plants. To date insight into the infiltration behaviour of liquid elemental mercury in the subsurface is lacking, although this is critical for assessing both characterization and remediation approaches for mercury DNAPL contaminated sites. Therefore, in this study the infiltration behaviour of elemental mercury in fully and partially water saturated systems was investigated using column experiments. The properties affecting the constitutive relations governing the infiltration behaviour of liquid Hg0, and PCE for comparison, were determined using Pc(S) experiments with different granular porous media (glass beads and sands) for different two- and three-phase configurations. Results showed that, in water saturated porous media, elemental mercury, as PCE, acted as a non-wetting fluid. The required entry head for elemental mercury was higher (from about 5 to 7 times). However, due to the almost tenfold higher density of mercury, the required NAPL entry heads of 6.19 cm and 12.51 cm for mercury to infiltrate were 37.5% to 20.7% lower than for PCE for the same porous media. Although Leverett scaling was able to reproduce the natural tendency of Hg0 to be more prone than PCE to infiltrate in water saturated porous media, it considerably underestimated Hg0 infiltration capacity in comparison with the experimental results. In the partially water saturated system, in contrast with PCE, elemental mercury also acted as a nonwetting fluid, therefore having to overcome an entry head to infiltrate. The required Hg0 entry heads (10.45 and 15.74 cm) were considerably higher (68.9% and 25.8%) than for the water saturated porous systems. Furthermore, in the partially water saturated systems, experiments showed that elemental mercury displaced both air and water, depending on the initial water distribution within the pores. This indicates that the conventional wettability hierarchy, in which the NAPL has an intermediate wetting state between the air and the water phases, is not valid for liquid elemental mercury. Therefore, for future modelling of elemental mercury DNAPL infiltration behaviour in variably water saturated porous media, a different formulation of the governing constitutive relations will be required.

Evidence for montmorillonite or its compositional equivalent in Columbia Hills, Mars

USGS Publications Warehouse

Clark, B. C.; Arvidson, R. E.; Gellert, Ralf; Morris, R.V.; Ming, D. W.; Richter, L.; Ruff, S.W.; Michalski, J.R.; Farrand, W. H.; Yen, A. S.; Herkenhoff, K. E.; Li, R.; Squyres, S. W.; Schroder, C.; Klingelhofer, G.; Bell, J.F.

2007-01-01

During its exploration of the Columbia Hills, the Mars Exploration Rover "Spirit" encountered several similar samples that are distinctly different from Martian meteorites and known Gusev crater soils, rocks, and sediments. Occurring in a variety of contexts and locations, these "Independence class" samples are rough-textured, iron-poor (equivalent FeO ??? 4 wt%), have high Al/Si ratios, and often contain unexpectedly high concentrations of one or more minor or trace elements (including Cr, Ni, Cu, Sr, and Y). Apart from accessory minerals, the major component common to these samples has a compositional profile of major and minor elements which is similar to the smectite montmorillonite, implicating this mineral, or its compositional equivalent. Infrared thermal emission spectra do not indicate the presence of crystalline smectite. One of these samples was found spatially associated with a ferric sulfate-enriched soil horizon, possibly indicating a genetic relationship between these disparate types of materials. Compared to the nearby Wishstone and Watchtower class rocks, major aqueous alteration involving mineral dissolution and mobilization with consequent depletions of certain elements is implied for this setting and may be undetectable by remote sensing from orbit because of the small scale of the occurrences and obscuration by mantling with soil and dust. Copyright 2007 by the American Geophysical Union.

On the estimate of deviations of partial sums of a multiple Fourier-Walsh series of the form S2j,⋯,2jf (x ) of a function in the metric L1(Qk)

NASA Astrophysics Data System (ADS)

Igenberlina, Alua; Matin, Dauren; Turgumbayev, Mendybay

2017-09-01

In this paper, deviations of the partial sums of a multiple Fourier-Walsh series of a function in the metric L1(Qk) on a dyadic group are investigated. This estimate plays an important role in the study of equivalent normalizations in this space by means of a difference, oscillation, and best approximation by polynomials in the Walsh system. The classical classical Besov space and its equivalent normalizations are set forth in the well-known monographs of Nikolsky S.M., Besov O.V., Ilyin V.P., Triebel H.; in the works of Kazakh scientists such as Amanov T.I., Mynbaev K.T., Otelbaev M.O., Smailov E.S.. The Besov spaces on the dyadic group and the Vilenkin groups in the one-dimensional case are considered in works by Ombe H., Bloom Walter R, Fournier J., Onneweer C.W., Weyi S., Jun Tateoka.

Cognitive Load in Algebra: Element Interactivity in Solving Equations

ERIC Educational Resources Information Center

Ngu, Bing Hiong; Chung, Siu Fung; Yeung, Alexander Seeshing

2015-01-01

Central to equation solving is the maintenance of equivalence on both sides of the equation. However, when the process involves an interaction of multiple elements, solving an equation can impose a high cognitive load. The balance method requires operations on both sides of the equation, whereas the inverse method involves operations on one side…

Sensitivity of Inverse Estimation of 2004 Elemental Carbon Emissions Inventory in the United States to the Choice of Observational Networks

EPA Science Inventory

Choice of observational networks used for inverse re-estimation of elemental (or black) carbon (EC) emissions in the United States impacts results. We convert the Thermal Optical Transmittance (TOT) EC measurements to the Thermal Optical Reflectance (TOR) equivalent to make full...

A preliminary investigation of finite-element modeling for composite rotor blades

NASA Technical Reports Server (NTRS)

Lake, Renee C.; Nixon, Mark W.

1988-01-01

The results from an initial phase of an in-house study aimed at improving the dynamic and aerodynamic characteristics of composite rotor blades through the use of elastic couplings are presented. Large degree of freedom shell finite element models of an extension twist coupled composite tube were developed and analyzed using MSC/NASTRAN. An analysis employing a simplified beam finite element representation of the specimen with the equivalent engineering stiffness was additionally performed. Results from the shell finite element normal modes and frequency analysis were compared to those obtained experimentally, showing an agreement within 13 percent. There was appreciable degradation in the frequency prediction for the torsional mode, which is elastically coupled. This was due to the absence of off-diagonal coupling terms in the formulation of the equivalent engineering stiffness. Parametric studies of frequency variation due to small changes in ply orientation angle and ply thickness were also performed. Results showed linear frequency variations less than 2 percent per 1 degree variation in the ply orientation angle, and 1 percent per 0.0001 inch variation in the ply thickness.

Striking Similarity in the Gene Expression Levels of Individual Myc Module Members among ESCs, EpiSCs, and Partial iPSCs

PubMed Central

Hirasaki, Masataka; Hiraki-Kamon, Keiko; Kamon, Masayoshi; Suzuki, Ayumu; Katano, Miyuki; Nishimoto, Masazumi; Okuda, Akihiko

2013-01-01

Predominant transcriptional subnetworks called Core, Myc, and PRC modules have been shown to participate in preservation of the pluripotency and self-renewality of embryonic stem cells (ESCs). Epiblast stem cells (EpiSCs) are another cell type that possesses pluripotency and self-renewality. However, the roles of these modules in EpiSCs have not been systematically examined to date. Here, we compared the average expression levels of Core, Myc, and PRC module genes between ESCs and EpiSCs. EpiSCs showed substantially higher and lower expression levels of PRC and Core module genes, respectively, compared with those in ESCs, while Myc module members showed almost equivalent levels of average gene expression. Subsequent analyses revealed that the similarity in gene expression levels of the Myc module between these two cell types was not just overall, but striking similarities were evident even when comparing the expression of individual genes. We also observed equivalent levels of similarity in the expression of individual Myc module genes between induced pluripotent stem cells (iPSCs) and partial iPSCs that are an unwanted byproduct generated during iPSC induction. Moreover, our data demonstrate that partial iPSCs depend on a high level of c-Myc expression for their self-renewal properties. PMID:24386274

Research on the equivalence between digital core and rock physics models

NASA Astrophysics Data System (ADS)

Yin, Xingyao; Zheng, Ying; Zong, Zhaoyun

2017-06-01

In this paper, we calculate the elastic modulus of 3D digital cores using the finite element method, systematically study the equivalence between the digital core model and various rock physics models, and carefully analyze the conditions of the equivalence relationships. The influences of the pore aspect ratio and consolidation coefficient on the equivalence relationships are also further refined. Theoretical analysis indicates that the finite element simulation based on the digital core is equivalent to the boundary theory and Gassmann model. For pure sandstones, effective medium theory models (SCA and DEM) and the digital core models are equivalent in cases when the pore aspect ratio is within a certain range, and dry frame models (Nur and Pride model) and the digital core model are equivalent in cases when the consolidation coefficient is a specific value. According to the equivalence relationships, the comparison of the elastic modulus results of the effective medium theory and digital rock physics is an effective approach for predicting the pore aspect ratio. Furthermore, the traditional digital core models with two components (pores and matrix) are extended to multiple minerals to more precisely characterize the features and mineral compositions of rocks in underground reservoirs. This paper studies the effects of shale content on the elastic modulus in shaly sandstones. When structural shale is present in the sandstone, the elastic modulus of the digital cores are in a reasonable agreement with the DEM model. However, when dispersed shale is present in the sandstone, the Hill model cannot describe the changes in the stiffness of the pore space precisely. Digital rock physics describes the rock features such as pore aspect ratio, consolidation coefficient and rock stiffness. Therefore, digital core technology can, to some extent, replace the theoretical rock physics models because the results are more accurate than those of the theoretical models.

SOLVENT EXTRACTION PROCESS FOR SEPARATING URANIUM AND PLUTONIUM FROM AQUEOUS ACIDIC SOLUTIONS OF NEUTRON IRRADIATED URANIUM

DOEpatents

Bruce, F.R.

1962-07-24

A solvent extraction process was developed for separating actinide elements including plutonium and uranium from fission products. By this method the ion content of the acidic aqueous solution is adjusted so that it contains more equivalents of total metal ions than equivalents of nitrate ions. Under these conditions the extractability of fission products is greatly decreased. (AEC)

Laser Setup for Volume Diffractive Optical Elements Recording in Photo-Thermo-Refractive Glass

DTIC Science & Technology

2016-04-14

Total Number: PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: Sub Contractors (DD882) Names of...3 1b 2 3 a b Fig. 14. Schematic of a DBR (a) and DFB (b) lasers in Yb doped PTR glass. 1a and 1b – dichroic beam splitters with HR at 1066 nm and HT

ACGT-containing abscisic acid response element (ABRE) and coupling element 3 (CE3) are functionally equivalent.

PubMed

Hobo, T; Asada, M; Kowyama, Y; Hattori, T

1999-09-01

ACGT-containing ABA response elements (ABREs) have been functionally identified in the promoters of various genes. In addition, single copies of ABRE have been found to require a cis-acting, coupling element to achieve ABA induction. A coupling element 3 (CE3) sequence, originally identified as such in the barley HVA1 promoter, is found approximately 30 bp downstream of motif A (ACGT-containing ABRE) in the promoter of the Osem gene. The relationship between these two elements was further defined by linker-scan analyses of a 55 bp fragment of the Osem promoter, which is sufficient for ABA-responsiveness and VP1 activation. The analyses revealed that both motif A and CE3 sequence were required not only for ABA-responsiveness but also for VP1 activation. Since the sequences of motif A and CE3 were found to be similar, motif-exchange experiments were carried out. The experiments demonstrated that motif A and CE3 were interchangeable by each other with respect to both ABA and VP1 regulation. In addition, both sequences were shown to be recognized by a VP1-interacting, ABA-responsive bZIP factor TRAB1. These results indicate that ACGT-containing ABREs and CE3 are functionally equivalent cis-acting elements. Furthermore, TRAB1 was shown to bind two other non-ACGT ABREs. Based on these results, all these ABREs including CE3 are proposed to be categorized into a single class of cis-acting elements.

Experimental validation of solid rocket motor damping models

NASA Astrophysics Data System (ADS)

Riso, Cristina; Fransen, Sebastiaan; Mastroddi, Franco; Coppotelli, Giuliano; Trequattrini, Francesco; De Vivo, Alessio

2017-12-01

In design and certification of spacecraft, payload/launcher coupled load analyses are performed to simulate the satellite dynamic environment. To obtain accurate predictions, the system damping properties must be properly taken into account in the finite element model used for coupled load analysis. This is typically done using a structural damping characterization in the frequency domain, which is not applicable in the time domain. Therefore, the structural damping matrix of the system must be converted into an equivalent viscous damping matrix when a transient coupled load analysis is performed. This paper focuses on the validation of equivalent viscous damping methods for dynamically condensed finite element models via correlation with experimental data for a realistic structure representative of a slender launch vehicle with solid rocket motors. A second scope of the paper is to investigate how to conveniently choose a single combination of Young's modulus and structural damping coefficient—complex Young's modulus—to approximate the viscoelastic behavior of a solid propellant material in the frequency band of interest for coupled load analysis. A scaled-down test article inspired to the Z9-ignition Vega launcher configuration is designed, manufactured, and experimentally tested to obtain data for validation of the equivalent viscous damping methods. The Z9-like component of the test article is filled with a viscoelastic material representative of the Z9 solid propellant that is also preliminarily tested to investigate the dependency of the complex Young's modulus on the excitation frequency and provide data for the test article finite element model. Experimental results from seismic and shock tests performed on the test configuration are correlated with numerical results from frequency and time domain analyses carried out on its dynamically condensed finite element model to assess the applicability of different equivalent viscous damping methods to describe damping properties of slender launch vehicles in payload/launcher coupled load analysis.

Experimental validation of solid rocket motor damping models

NASA Astrophysics Data System (ADS)

Riso, Cristina; Fransen, Sebastiaan; Mastroddi, Franco; Coppotelli, Giuliano; Trequattrini, Francesco; De Vivo, Alessio

2018-06-01

In design and certification of spacecraft, payload/launcher coupled load analyses are performed to simulate the satellite dynamic environment. To obtain accurate predictions, the system damping properties must be properly taken into account in the finite element model used for coupled load analysis. This is typically done using a structural damping characterization in the frequency domain, which is not applicable in the time domain. Therefore, the structural damping matrix of the system must be converted into an equivalent viscous damping matrix when a transient coupled load analysis is performed. This paper focuses on the validation of equivalent viscous damping methods for dynamically condensed finite element models via correlation with experimental data for a realistic structure representative of a slender launch vehicle with solid rocket motors. A second scope of the paper is to investigate how to conveniently choose a single combination of Young's modulus and structural damping coefficient—complex Young's modulus—to approximate the viscoelastic behavior of a solid propellant material in the frequency band of interest for coupled load analysis. A scaled-down test article inspired to the Z9-ignition Vega launcher configuration is designed, manufactured, and experimentally tested to obtain data for validation of the equivalent viscous damping methods. The Z9-like component of the test article is filled with a viscoelastic material representative of the Z9 solid propellant that is also preliminarily tested to investigate the dependency of the complex Young's modulus on the excitation frequency and provide data for the test article finite element model. Experimental results from seismic and shock tests performed on the test configuration are correlated with numerical results from frequency and time domain analyses carried out on its dynamically condensed finite element model to assess the applicability of different equivalent viscous damping methods to describe damping properties of slender launch vehicles in payload/launcher coupled load analysis.

Complex matrix multiplication operations with data pre-conditioning in a high performance computing architecture

DOEpatents

Eichenberger, Alexandre E; Gschwind, Michael K; Gunnels, John A

2014-02-11

Mechanisms for performing a complex matrix multiplication operation are provided. A vector load operation is performed to load a first vector operand of the complex matrix multiplication operation to a first target vector register. The first vector operand comprises a real and imaginary part of a first complex vector value. A complex load and splat operation is performed to load a second complex vector value of a second vector operand and replicate the second complex vector value within a second target vector register. The second complex vector value has a real and imaginary part. A cross multiply add operation is performed on elements of the first target vector register and elements of the second target vector register to generate a partial product of the complex matrix multiplication operation. The partial product is accumulated with other partial products and a resulting accumulated partial product is stored in a result vector register.

A finite element evaluation of mechanical function for 3 distal extension partial dental prosthesis designs with a 3-dimensional nonlinear method for modeling soft tissue.

PubMed

Nakamura, Yoshinori; Kanbara, Ryo; Ochiai, Kent T; Tanaka, Yoshinobu

2014-10-01

The mechanical evaluation of the function of partial removable dental prostheses with 3-dimensional finite element modeling requires the accurate assessment and incorporation of soft tissue behavior. The differential behaviors of the residual ridge mucosa and periodontal ligament tissues have been shown to exhibit nonlinear displacement. The mathematic incorporation of known values simulating nonlinear soft tissue behavior has not been investigated previously via 3-dimensional finite element modeling evaluation to demonstrate the effect of prosthesis design on the supporting tissues. The purpose of this comparative study was to evaluate the functional differences of 3 different partial removable dental prosthesis designs with 3-dimensional finite element analysis modeling and a simulated patient model incorporating known viscoelastic, nonlinear soft tissue properties. Three different designs of distal extension removable partial dental prostheses were analyzed. The stress distributions to the supporting abutments and soft tissue displacements of the designs tested were calculated and mechanically compared. Among the 3 dental designs evaluated, the RPI prosthesis demonstrated the lowest stress concentrations on the tissue supporting the tooth abutment and also provided wide mucosa-borne areas of support, thereby demonstrating a mechanical advantage and efficacy over the other designs evaluated. The data and results obtained from this study confirmed that the functional behavior of partial dental prostheses with supporting abutments and soft tissues are consistent with the conventional theories of design and clinical experience. The validity and usefulness of this testing method for future applications and testing protocols are shown. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Origin and geodynamic setting of Late Cenozoic granitoids in Sulawesi, Indonesia

NASA Astrophysics Data System (ADS)

Maulana, Adi; Imai, Akira; Van Leeuwen, Theo; Watanabe, Koichiro; Yonezu, Kotaro; Nakano, Takanori; Boyce, Adrian; Page, Laurence; Schersten, Anders

2016-07-01

Late Cenozoic granitoids are widespread in a 1600 km long belt forming the Western and Northern Sulawesi tectono-magmatic provinces. They can be divided into three rock series: shoshonitic (HK), high-K felsic calc-alkaline (CAK), and normal calc-alkaline to tholeiitic (CA-TH). Representative samples collected from eleven plutons, which were subjected to petrography, major element, trace element, Sr, Nd, Pb isotope and whole-rock δ18O analyses, are all I-type and metaluminous to weakly peraluminous. The occurrence of the two K-rich series is restricted to Western Sulawesi, where they formed in an extensional, post-subduction tectonic setting with astenospheric upwelling providing thermal perturbation and adiabatic decompression. Two parental magma sources are proposed: enriched mantle or lower crustal equivalent for HK magmas, and Triassic igneous rocks in a Gondwana-derived fragment thrust beneath the cental and northern parts of Western Sulawesi for CAK magmas. The latter interpretation is based on striking similarities in radiogenic isotope and trace element signatures. CA-TH granitoids are found mostly in Northern Sulawesi. Partial melting of lower-middle crust amphibolites in an active subduction environment is the proposed origin of these rocks. Fractional crystallization and crustal contamination have played a significant role in magma petrogenesis, particularly in the case of the HK and CAK series. Contamination by organic carbon-bearing sedimentary rocks of the HK and CAK granitoids in the central part of Western Sulawesi is suggested by their ilmenite-series (reduced) character. The CAK granitoids further to the north and CA-TH granitoids in Northern Sulawesi are typical magnetite-series (oxidized). This may explain differences in mineralization styles in the two regions.

Anatomic partial nephrectomy: technique evolution.

PubMed

Azhar, Raed A; Metcalfe, Charles; Gill, Inderbir S

2015-03-01

Partial nephrectomy provides equivalent long-term oncologic and superior functional outcomes as radical nephrectomy for T1a renal masses. Herein, we review the various vascular clamping techniques employed during minimally invasive partial nephrectomy, describe the evolution of our partial nephrectomy technique and provide an update on contemporary thinking about the impact of ischemia on renal function. Recently, partial nephrectomy surgical technique has shifted away from main artery clamping and towards minimizing/eliminating global renal ischemia during partial nephrectomy. Supported by high-fidelity three-dimensional imaging, novel anatomic-based partial nephrectomy techniques have recently been developed, wherein partial nephrectomy can now be performed with segmental, minimal or zero global ischemia to the renal remnant. Sequential innovations have included early unclamping, segmental clamping, super-selective clamping and now culminating in anatomic zero-ischemia surgery. By eliminating 'under-the-gun' time pressure of ischemia for the surgeon, these techniques allow an unhurried, tightly contoured tumour excision with point-specific sutured haemostasis. Recent data indicate that zero-ischemia partial nephrectomy may provide better functional outcomes by minimizing/eliminating global ischemia and preserving greater vascularized kidney volume. Contemporary partial nephrectomy includes a spectrum of surgical techniques ranging from conventional-clamped to novel zero-ischemia approaches. Technique selection should be tailored to each individual case on the basis of tumour characteristics, surgical feasibility, surgeon experience, patient demographics and baseline renal function.

Effects of asynchrony and ear of presentation on the pitch of mistuned partials in harmonic and frequency-shifted complex tones.

PubMed

Brunstrom, J M; Roberts, B

2001-07-01

When a partial of a periodic complex is mistuned, its change in pitch is greater than expected. Two experiments examined whether these partial-pitch shifts are related to the computation of global pitch. In experiment 1, stimuli were either harmonic or frequency-shifted (25% of F0) complexes. One partial was mistuned by +/- 4% and played with leading and lagging portions of 500 ms each, relative to the other components (1 s), in both monaural and dichotic contexts. Subjects indicated whether the mistuned partial was higher or lower in pitch when concurrent with the other components. Responses were positively correlated with the direction of mistuning in all conditions. In experiment 2, stimuli from each condition were compared with synchronous equivalents. Subjects matched a pure tone to the pitch of the mistuned partial (component 4). The results showed that partial-pitch shifts are not reduced in size by asynchrony. Similar asynchronies are known to produce a near-exclusion of a mistuned partial from the global-pitch computation. This mismatch indicates that global and partial pitch are derived from different processes. The similarity of the partial-pitch shifts observed for harmonic and frequency-shifted stimuli suggests that they arise from a grouping mechanism that is sensitive to spectral regularity.

Study of cross-shaped ultrasonic array sensor applied to partial discharge location in transformer oil.

PubMed

Li, Jisheng; Xin, Xiaohu; Luo, Yongfen; Ji, Haiying; Li, Yanming; Deng, Junbo

2013-11-01

A conformal combined sensor is designed and it is used in Partial Discharge (PD) location experiments in transformer oil. The sensor includes a cross-shaped ultrasonic phased array of 13 elements and an ultra-high-frequency (UHF) electromagnetic rectangle array of 2 × 2 elements. Virtual expansion with high order cumulants, the ultrasonic array can achieve the effect of array with 61 elements. This greatly improves the aperture and direction sharpness of original array and reduces the cost of follow-up hardware. With the cross-shaped ultrasonic array, the results of PD location experiments are precise and the maximum error of the direction of arrival (DOA) is less than 5°.

Generalized serial search code acquisition - The equivalent circular state diagram approach

NASA Technical Reports Server (NTRS)

Polydoros, A.; Simon, M. K.

1984-01-01

A transform-domain method for deriving the generating function of the acquisition process resulting from an arbitrary serial search strategy is presented. The method relies on equivalent circular state diagrams, uses Mason's formula from flow-graph theory, and employs a minimum number of required parameters. The transform-domain approach is briefly described and the concept of equivalent circular state diagrams is introduced and exploited to derive the generating function and resulting mean acquisition time for three particular cases of interest, the continuous/center Z search, the broken/center Z search, and the expanding window search. An optimization of the latter technique is performed whereby the number of partial windows which minimizes the mean acquisition time is determined. The numerical results satisfy certain intuitive predictions and provide useful design guidelines for such systems.

Recent Progress in the p and h-p Version of the Finite Element Method.

DTIC Science & Technology

1987-07-01

code PROBE which was developed recently by NOETIC Technologies, St. Louis £54]. PROBE solves two dimensional problems of linear elasticity, stationary...of the finite element method was studied in detail from various point of view. We will mention here some essential illustrative results. In one...28) Bathe, K. J., Brezzi, F., Studies of finite element procedures - the INF-SUP condition, equivalent forms and applications in Reliability of

BROJA-2PID: A Robust Estimator for Bivariate Partial Information Decomposition

NASA Astrophysics Data System (ADS)

Makkeh, Abdullah; Theis, Dirk; Vicente, Raul

2018-04-01

Makkeh, Theis, and Vicente found in [8] that Cone Programming model is the most robust to compute the Bertschinger et al. partial information decompostion (BROJA PID) measure [1]. We developed a production-quality robust software that computes the BROJA PID measure based on the Cone Programming model. In this paper, we prove the important property of strong duality for the Cone Program and prove an equivalence between the Cone Program and the original Convex problem. Then describe in detail our software and how to use it.\

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.

SU-D-BRC-04: Development of Proton Tissue Equivalent Materials for Calibration and Dosimetry Studies

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

Olguin, E; Flampouri, S; Lipnharski, I

Purpose: To develop new proton tissue equivalent materials (PTEM), urethane and fiberglass based, for proton therapy calibration and dosimetry studies. Existing tissue equivalent plastics are applicable only for x-rays because they focus on matching mass attenuation coefficients. This study aims to create new plastics that match mass stopping powers for proton therapy applications instead. Methods: New PTEMs were constructed using urethane and fiberglass resin materials for soft, fat, bone, and lung tissue. The stoichiometric analysis method was first used to determine the elemental composition of each unknown constituent. New initial formulae were then developed for each of the 4 PTEMsmore » using the new elemental compositions and various additives. Samples of each plastic were then created and exposed to a well defined proton beam at the UF Health Proton Therapy Institute (UFHPTI) to validate its mass stopping power. Results: The stoichiometric analysis method revealed the elemental composition of the 3 components used in creating the PTEMs. These urethane and fiberglass based resins were combined with additives such as calcium carbonate, aluminum hydroxide, and phenolic micro spheres to achieve the desired mass stopping powers and densities. Validation at the UFHPTI revealed adjustments had to be made to the formulae, but the plastics eventually had the desired properties after a few iterations. The mass stopping power, density, and Hounsfield Unit of each of the 4 PTEMs were within acceptable tolerances. Conclusion: Four proton tissue equivalent plastics were developed: soft, fat, bone, and lung tissue. These plastics match each of the corresponding tissue’s mass stopping power, density, and Hounsfield Unit, meaning they are truly tissue equivalent for proton therapy applications. They can now be used to calibrate proton therapy treatment planning systems, improve range uncertainties, validate proton therapy Monte Carlo simulations, and assess in-field and out-of-field organ doses.« less

Microelectromechanical Systems Actuator Based Reconfigurable Printed Antenna

NASA Technical Reports Server (NTRS)

Simons, Rainee N. (Inventor)

2005-01-01

A polarization reconfigurable patch antenna is disclosed. The antenna includes a feed element, a patch antenna element electrically connected to the feed element, and at least one microelectromechanical systems (MEMS) actuator, with a partial connection to the patch antenna element along an edge of the patch antenna element. The polarization of the antenna can be switched between circular polarization and linear polarization through action of the at least one MEMS actuator.

Spectral methods on arbitrary grids

NASA Technical Reports Server (NTRS)

Carpenter, Mark H.; Gottlieb, David

1995-01-01

Stable and spectrally accurate numerical methods are constructed on arbitrary grids for partial differential equations. These new methods are equivalent to conventional spectral methods but do not rely on specific grid distributions. Specifically, we show how to implement Legendre Galerkin, Legendre collocation, and Laguerre Galerkin methodology on arbitrary grids.

Measurement equivalence of patient safety climate in Chinese hospitals: can we compare across physicians and nurses?

PubMed

Zhu, Junya

2018-06-11

Self-report instruments have been widely used to better understand variations in patient safety climate between physicians and nurses. Research is needed to determine whether differences in patient safety climate reflect true differences in the underlying concepts. This is known as measurement equivalence, which is a prerequisite for meaningful group comparisons. This study aims to examine the degree of measurement equivalence of the responses to a patient safety climate survey of Chinese hospitals and to demonstrate how the measurement equivalence method can be applied to self-report climate surveys for patient safety research. Using data from the Chinese Hospital Survey of Patient Safety Climate from six Chinese hospitals in 2011, we constructed two groups: physicians and nurses (346 per group). We used multiple-group confirmatory factor analyses to examine progressively more stringent restrictions for measurement equivalence. We identified weak factorial equivalence across the two groups. Strong factorial equivalence was found for Organizational Learning, Unit Management Support for Safety, Adequacy of Safety Arrangements, Institutional Commitment to Safety, Error Reporting and Teamwork. Strong factorial equivalence, however, was not found for Safety System, Communication and Peer Support and Staffing. Nevertheless, further analyses suggested that nonequivalence did not meaningfully affect the conclusions regarding physician-nurse differences in patient safety climate. Our results provide evidence of at least partial equivalence of the survey responses between nurses and physicians, supporting mean comparisons of its constructs between the two groups. The measurement equivalence approach is essential to ensure that conclusions about group differences are valid.

Scattering Properties of Needle-Like and plate-like Ice Spheroids with Moderate Size Parameters

NASA Technical Reports Server (NTRS)

Zakharova, Nadia T.; Mishchenko, Michael I.; Hansen, James E. (Technical Monitor)

2000-01-01

We use the current advanced version of the T-matrix method to compute the optical cross sections, the asymmetry parameter of the phase function, and the scattering matrix elements of ice spheroids with aspect ratios up to 20 and surface-equivalent-sphere size parameters up to 12. We demonstrate that plate-like and needle-like particles with moderate size parameters possess unique scattering properties: their asymmetry parameters and phase functions are similar to those of surface-equivalent spheres, whereas all other elements of the scattering matrix are typical of particles much smaller than the wavelength (Rayleigh scatterers). This result may have important implications for optical particle sizing and remote sensing of the terrestrial and planetary atmospheres.

EQUIVALENCE BETWEEN SHORT-TIME BIPHASIC AND INCOMPRESSIBLE ELASTIC MATERIAL RESPONSES

PubMed Central

Ateshian, Gerard A.; Ellis, Benjamin J.; Weiss, Jeffrey A.

2009-01-01

Porous-permeable tissues have often been modeled using porous media theories such as the biphasic theory. This study examines the equivalence of the short-time biphasic and incompressible elastic responses for arbitrary deformations and constitutive relations from first principles. This equivalence is illustrated in problems of unconfined compression of a disk, and of articular contact under finite deformation, using two different constitutive relations for the solid matrix of cartilage, one of which accounts for the large disparity observed between the tensile and compressive moduli in this tissue. Demonstrating this equivalence under general conditions provides a rationale for using available finite element codes for incompressible elastic materials as a practical substitute for biphasic analyses, so long as only the short-time biphasic response is sought. In practice, an incompressible elastic analysis is representative of a biphasic analysis over the short-term response δt≪Δ2/‖C4‖||K||, where Δ is a characteristic dimension, C4 is the elasticity tensor and K is the hydraulic permeability tensor of the solid matrix. Certain notes of caution are provided with regard to implementation issues, particularly when finite element formulations of incompressible elasticity employ an uncoupled strain energy function consisting of additive deviatoric and volumetric components. PMID:17536908

46 CFR 151.50-50 - Elemental phosphorus in water.

Code of Federal Regulations, 2012 CFR

2012-10-01

.... (b) When a water displacement method of discharge is used, pressure vessel type cargo tanks, designed... 46 Shipping 5 2012-10-01 2012-10-01 false Elemental phosphorus in water. 151.50-50 Section 151.50... phosphorus in water. (a) Tanks shall be designed and tested for a head equivalent to the design lading of...

46 CFR 151.50-50 - Elemental phosphorus in water.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Elemental phosphorus in water. 151.50-50 Section 151.50... phosphorus in water. (a) Tanks shall be designed and tested for a head equivalent to the design lading of phosphorus and its water blanket extended to 8 feet above the tank top. In addition, tank design calculations...

46 CFR 151.50-50 - Elemental phosphorus in water.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Elemental phosphorus in water. 151.50-50 Section 151.50... phosphorus in water. (a) Tanks shall be designed and tested for a head equivalent to the design lading of phosphorus and its water blanket extended to 8 feet above the tank top. In addition, tank design calculations...

46 CFR 151.50-50 - Elemental phosphorus in water.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Elemental phosphorus in water. 151.50-50 Section 151.50... phosphorus in water. (a) Tanks shall be designed and tested for a head equivalent to the design lading of phosphorus and its water blanket extended to 8 feet above the tank top. In addition, tank design calculations...

46 CFR 151.50-50 - Elemental phosphorus in water.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Elemental phosphorus in water. 151.50-50 Section 151.50... phosphorus in water. (a) Tanks shall be designed and tested for a head equivalent to the design lading of phosphorus and its water blanket extended to 8 feet above the tank top. In addition, tank design calculations...

Finite element simulation of piezoelectric transformers.

PubMed

Tsuchiya, T; Kagawa, Y; Wakatsuki, N; Okamura, H

2001-07-01

Piezoelectric transformers are nothing but ultrasonic resonators with two pairs of electrodes provided on the surface of a piezoelectric substrate in which electrical energy is carried in the mechanical form. The input and output electrodes are arranged to provide the impedance transformation, which results in the voltage transformation. As they are operated at a resonance, the electrical equivalent circuit approach has traditionally been developed in a rather empirical way and has been used for analysis and design. The present paper deals with the analysis of the piezoelectric transformers based on the three-dimensional finite element modelling. The PIEZO3D code that we have developed is modified to include the external loading conditions. The finite element approach is now available for a wide variety of the electrical boundary conditions. The equivalent circuit of lumped parameters can also be derived from the finite element method (FEM) solution if required. The simulation of the present transformers is made for the low intensity operation and compared with the experimental results. Demonstration is made for basic Rosen-type transformers in which the longitudinal mode of a plate plays an important role; in which the equivalent circuit of lumped constants has been used. However, there are many modes of vibration associated with the plate, the effect of which cannot always be ignored. In the experiment, the double resonances are sometimes observed in the vicinity of the operating frequency. The simulation demonstrates that this is due to the coupling of the longitudinal mode with the flexural mode. Thus, the simulation provides an invaluable guideline to the transformer design.

Effects of Fuel Distribution on Detonation Tube Performance

NASA Technical Reports Server (NTRS)

Perkins, Hugh Douglas

2002-01-01

A pulse detonation engine (PDE) uses a series of high frequency intermittent detonation tubes to generate thrust. The process of filling the detonation tube with fuel and air for each cycle may yield non-uniform mixtures. Lack of mixture uniformity is commonly ignored when calculating detonation tube thrust performance. In this study, detonation cycles featuring idealized non-uniform H2/air mixtures were analyzed using the SPARK two-dimensional Navier-Stokes CFD code with 7-step H2/air reaction mechanism. Mixture non-uniformities examined included axial equivalence ratio gradients, transverse equivalence ratio gradients, and partially fueled tubes. Three different average test section equivalence ratios (phi), stoichiometric (phi = 1.00), fuel lean (phi = 0.90), and fuel rich (phi = 1.10), were studied. All mixtures were detonable throughout the detonation tube. It was found that various mixtures representing the same test section equivalence ratio had specific impulses within 1 percent of each other, indicating that good fuel/air mixing is not a prerequisite for optimal detonation tube performance.

Nonlinear initial-boundary value solutions by the finite element method. [for Navier-Stokes equations of two dimensional flow

NASA Technical Reports Server (NTRS)

Baker, A. J.

1974-01-01

The finite-element method is used to establish a numerical solution algorithm for the Navier-Stokes equations for two-dimensional flows of a viscous compressible fluid. Numerical experiments confirm the advection property for the finite-element equivalent of the nonlinear convection term for both unidirectional and recirculating flowfields. For linear functionals, the algorithm demonstrates good accuracy using coarse discretizations and h squared convergence with discretization refinement.

Development of a multi-element microdosimetric detector based on a thick gas electron multiplier

NASA Astrophysics Data System (ADS)

Anjomani, Z.; Hanu, A. R.; Prestwich, W. V.; Byun, S. H.

2017-03-01

A prototype multi-element gaseous microdosimetric detector was developed using the Thick Gas Electron Multiplier (THGEM) technique. The detector aims at measuring neutron and gamma-ray dose rates for weak neutron-gamma radiation fields. The multi-element design was employed to increase the neutron detection efficiency. The prototype THGEM multi-element detector consists of three layers of tissue equivalent plastic hexagons and each layer houses a hexagonal array of seven cylindrical gas cavity elements with equal heights and diameters of 17 mm. The final detector structure incorporates 21 gaseous volumes. Owing to the absence of wire electrodes, the THGEM multi-element detector offers flexible and convenient fabrication. The detector responses to neutron and gamma-ray were investigated using the McMaster Tandetron 7Li(p,n) neutron source. The dosimetric performance of the detector is presented in contrast to the response of a commercial tissue equivalent proportional counter. Compared to the standard TEPC response, the detector gave a consistent microdosimetric response with an average discrepancy of 8 % in measured neutron absorbed dose. An improvement of a factor of 3.0 in neutron detection efficiency has been accomplished with only a small degradation in energy resolution. However, its low energy cut off is about 6 keV/μm, which is not sufficient to measure the gamma-ray dose. This problem will be addressed by increasing the electron multiplication gain using double THGEM layers.

The Glass Floor: Education, Downward Mobility, and Opportunity Hoarding

ERIC Educational Resources Information Center

Reeves, Richard V.; Howard, Kimberly

2013-01-01

From an intergenerational perspective, the U.S. income distribution is sticky at both ends. Affluence and poverty are both partially inherited. Policy and research has focused on upward mobility, especially from the bottom. But relative intergenerational upward mobility is only possible with equivalent rates of downward mobility, where much less…

Going from microscopic to macroscopic on nonuniform growing domains.

PubMed

Yates, Christian A; Baker, Ruth E; Erban, Radek; Maini, Philip K

2012-08-01

Throughout development, chemical cues are employed to guide the functional specification of underlying tissues while the spatiotemporal distributions of such chemicals can be influenced by the growth of the tissue itself. These chemicals, termed morphogens, are often modeled using partial differential equations (PDEs). The connection between discrete stochastic and deterministic continuum models of particle migration on growing domains was elucidated by Baker, Yates, and Erban [Bull. Math. Biol. 72, 719 (2010)] in which the migration of individual particles was modeled as an on-lattice position-jump process. We build on this work by incorporating a more physically reasonable description of domain growth. Instead of allowing underlying lattice elements to instantaneously double in size and divide, we allow incremental element growth and splitting upon reaching a predefined threshold size. Such a description of domain growth necessitates a nonuniform partition of the domain. We first demonstrate that an individual-based stochastic model for particle diffusion on such a nonuniform domain partition is equivalent to a PDE model of the same phenomenon on a nongrowing domain, providing the transition rates (which we derive) are chosen correctly and we partition the domain in the correct manner. We extend this analysis to the case where the domain is allowed to change in size, altering the transition rates as necessary. Through application of the master equation formalism we derive a PDE for particle density on this growing domain and corroborate our findings with numerical simulations.

Gravity Effects Observed In Partially Premixed Flames

NASA Technical Reports Server (NTRS)

Puri, Ishwar K.; Aggarwal, Suresh K.; Lock, Andrew J.; Gauguly, Ranjan; Hegde, Uday

2003-01-01

Partially premixed flames (PPFs) contain a rich premixed fuel air mixture in a pocket or stream, and, for complete combustion to occur, they require the transport of oxidizer from an appropriately oxidizer-rich (or fuel-lean) mixture that is present in another pocket or stream. Partial oxidation reactions occur in fuel-rich portions of the mixture and any remaining unburned fuel and/or intermediate species are consumed in the oxidizer-rich portions. Partial premixing, therefore, represents that condition when the equivalence ratio (phi) in one portion of the flowfield is greater than unity, and in another section its value is less than unity. In general, for combustion to occur efficiently, the global equivalence ratio is in the range fuel-lean to stoichiometric. These flames can be established by design by placing a fuel-rich mixture in contact with a fuel-lean mixture, but they also occur otherwise in many practical systems, which include nonpremixed lifted flames, turbulent nonpremixed combustion, spray flames, and unwanted fires. Other practical applications of PPFs are reported elsewhere. Although extensive experimental studies have been conducted on premixed and nonpremixed flames under microgravity, there is a absence of previous experimental work on burner stabilized PPFs in this regard. Previous numerical studies by our group employing a detailed numerical model showed gravity effects to be significant on the PPF structure. We report on the results of microgravity experiments conducted on two-dimensional (established on a Wolfhard-Parker slot burner) and axisymmetric flames (on a coannular burner) that were investigated in a self-contained multipurpose rig. Thermocouple and radiometer data were also used to characterize the thermal transport in the flame.

Equivalent circuit parameters of nickel/metal hydride batteries from sparse impedance measurements

NASA Astrophysics Data System (ADS)

Nelatury, Sudarshan Rao; Singh, Pritpal

In a recent communication, a method for extracting the equivalent circuit parameters of a lead acid battery from sparse (only three) impedance spectroscopy observations at three different frequencies was proposed. It was based on an equivalent circuit consisting of a bulk resistance, a reaction resistance and a constant phase element (CPE). Such a circuit is a very appropriate model of a lead-acid cell at high state of charge (SOC). This paper is a sequel to it and presents an application of it in case of nickel/metal hydride (Ni/MH) batteries, which also at high SOC are represented by the same circuit configuration. But when the SOC of a Ni/MH battery under interrogation goes low, The EIS curve has a positive slope at the low frequency end and our technique yields complex values for the otherwise real circuit parameters, suggesting the need for additional elements in the equivalent circuit and a definite relationship between parameter consistency and SOC. To improvise the previous algorithm, in order that it works reasonably well at both high and low SOCs, we propose three more measurements—two at very low frequencies to include the Warburg response and one at a high frequency to model the series inductance, in addition to the three in the mid frequency band—totally six measurements. In most of the today's instrumentation, it is the user who should choose the circuit configuration and the number of frequencies where impedance should be measured and the accompanying software performs data fitting by complex nonlinear least squares. The proposed method has built into it an SOC-based decision-making capability—both to choose the circuit configuration and to estimate the values of the circuit elements.

Equivalent circuit modeling of a piezo-patch energy harvester on a thin plate with AC-DC conversion

NASA Astrophysics Data System (ADS)

Bayik, B.; Aghakhani, A.; Basdogan, I.; Erturk, A.

2016-05-01

As an alternative to beam-like structures, piezoelectric patch-based energy harvesters attached to thin plates can be readily integrated to plate-like structures in automotive, marine, and aerospace applications, in order to directly exploit structural vibration modes of the host system without mass loading and volumetric occupancy of cantilever attachments. In this paper, a multi-mode equivalent circuit model of a piezo-patch energy harvester integrated to a thin plate is developed and coupled with a standard AC-DC conversion circuit. Equivalent circuit parameters are obtained in two different ways: (1) from the modal analysis solution of a distributed-parameter analytical model and (2) from the finite-element numerical model of the harvester by accounting for two-way coupling. After the analytical modeling effort, multi-mode equivalent circuit representation of the harvester is obtained via electronic circuit simulation software SPICE. Using the SPICE software, electromechanical response of the piezoelectric energy harvester connected to linear and nonlinear circuit elements are computed. Simulation results are validated for the standard AC-AC and AC-DC configurations. For the AC input-AC output problem, voltage frequency response functions are calculated for various resistive loads, and they show excellent agreement with modal analysis-based analytical closed-form solution and with the finite-element model. For the standard ideal AC input-DC output case, a full-wave rectifier and a smoothing capacitor are added to the harvester circuit for conversion of the AC voltage to a stable DC voltage, which is also validated against an existing solution by treating the single-mode plate dynamics as a single-degree-of-freedom system.

Finite element 3D modeling of mechanical behavior of mineralized collagen microfibrils.

PubMed

Barkaoui, Abdelwahed; Hambli, Ridha

2011-01-01

The aim of this work is to develop a 3D finite elements model to study the nanomechanical behavior of mineralized collagen microfibrils, which consists of three phases, (i) collagen phase formed by five tropocollagen (TC) molecules linked together with cross-links, (ii) a mineral phase (Hydroxyapatite), and (iii) impure mineral phase, and to investigate the important role of individual properties of every constituent. The mechanical and geometric properties (TC molecule diameter) of both tropocollagen and mineral were taken into consideration as well as cross-links, which was represented by spring elements with adjusted properties based on experimental data. In this paper an equivalent homogenized model was developed to assess the whole microfibril mechanical properties (Young's modulus and Poisson's ratio) under varying mechanical properties of each phase. In this study, both equivalent Young's modulus and Poisson's ratio, which were expressed as functions of Young's modulus of each phase, were obtained under tensile load with symmetric and periodic boundary conditions.

Mode-based equivalent multi-degree-of-freedom system for one-dimensional viscoelastic response analysis of layered soil deposit

NASA Astrophysics Data System (ADS)

Li, Chong; Yuan, Juyun; Yu, Haitao; Yuan, Yong

2018-01-01

Discrete models such as the lumped parameter model and the finite element model are widely used in the solution of soil amplification of earthquakes. However, neither of the models will accurately estimate the natural frequencies of soil deposit, nor simulate a damping of frequency independence. This research develops a new discrete model for one-dimensional viscoelastic response analysis of layered soil deposit based on the mode equivalence method. The new discrete model is a one-dimensional equivalent multi-degree-of-freedom (MDOF) system characterized by a series of concentrated masses, springs and dashpots with a special configuration. The dynamic response of the equivalent MDOF system is analytically derived and the physical parameters are formulated in terms of modal properties. The equivalent MDOF system is verified through a comparison of amplification functions with the available theoretical solutions. The appropriate number of degrees of freedom (DOFs) in the equivalent MDOF system is estimated. A comparative study of the equivalent MDOF system with the existing discrete models is performed. It is shown that the proposed equivalent MDOF system can exactly present the natural frequencies and the hysteretic damping of soil deposits and provide more accurate results with fewer DOFs.

Modelling and Characterization of Effective Thermal Conductivity of Single Hollow Glass Microsphere and Its Powder.

PubMed

Liu, Bing; Wang, Hui; Qin, Qing-Hua

2018-01-14

Tiny hollow glass microsphere (HGM) can be applied for designing new light-weighted and thermal-insulated composites as high strength core, owing to its hollow structure. However, little work has been found for studying its own overall thermal conductivity independent of any matrix, which generally cannot be measured or evaluated directly. In this study, the overall thermal conductivity of HGM is investigated experimentally and numerically. The experimental investigation of thermal conductivity of HGM powder is performed by the transient plane source (TPS) technique to provide a reference to numerical results, which are obtained by a developed three-dimensional two-step hierarchical computational method. In the present method, three heterogeneous HGM stacking elements representing different distributions of HGMs in the powder are assumed. Each stacking element and its equivalent homogeneous solid counterpart are, respectively, embedded into a fictitious matrix material as fillers to form two equivalent composite systems at different levels, and then the overall thermal conductivity of each stacking element can be numerically determined through the equivalence of the two systems. The comparison of experimental and computational results indicates the present computational modeling can be used for effectively predicting the overall thermal conductivity of single HGM and its powder in a flexible way. Besides, it is necessary to note that the influence of thermal interfacial resistance cannot be removed from the experimental results in the TPS measurement.

Case Study: Microbial Ecology and Forensics of Chinese Drywall-Elemental Sulfur Disproportionation as Primary Generator of Hydrogen Sulfide.

PubMed

Tomei Torres, Francisco A

2017-06-21

Drywall manufactured in China released foul odors attributed to volatile sulfur compounds. These included hydrogen sulfide, methyl mercaptan, and sulfur dioxide. Given that calcium sulfate is the main component of drywall, one would suspect bacterial reduction of sulfate to sulfide as the primary culprit. However, when the forensics, i.e., the microbial and chemical signatures left in the drywall, are studied, the evidence suggests that, rather than dissimilatory sulfate reduction, disproportionation of elemental sulfur to hydrogen sulfide and sulfate was actually the primary cause of the malodors. Forensic evidence suggests that the transformation of elemental sulfur went through several abiological and microbial stages: (1) partial volatilization of elemental sulfur during the manufacture of plaster of Paris, (2) partial abiotic disproportionation of elemental sulfur to sulfide and thiosulfate during the manufacture of drywall, (3) microbial disproportionation of elemental sulfur to sulfide and sulfate resulting in neutralization of all alkalinity, and acidification below pH 4, (4) acidophilic microbial disproportionation of elemental sulfur to sulfide and sulfuric acid, and (5) hydrogen sulfide volatilization, coating of copper fixtures resulting in corrosion, and oxidation to sulfur dioxide.

Infiltration behaviour of elemental mercury DNAPL in fully and partially water saturated porous media.

PubMed

D'Aniello, Andrea; Hartog, Niels; Sweijen, Thomas; Pianese, Domenico

2018-02-01

Mercury is a contaminant of global concern due to its harmful effects on human health and for the detrimental consequences of its release in the environment. Sources of liquid elemental mercury are usually anthropogenic, such as chlor-alkali plants. To date insight into the infiltration behaviour of liquid elemental mercury in the subsurface is lacking, although this is critical for assessing both characterization and remediation approaches for mercury DNAPL contaminated sites. Therefore, in this study the infiltration behaviour of elemental mercury in fully and partially water saturated systems was investigated using column experiments. The properties affecting the constitutive relations governing the infiltration behaviour of liquid Hg 0 , and PCE for comparison, were determined using P c (S) experiments with different granular porous media (glass beads and sands) for different two- and three-phase configurations. Results showed that, in water saturated porous media, elemental mercury, as PCE, acted as a non-wetting fluid. The required entry head for elemental mercury was higher (from about 5 to 7 times). However, due to the almost tenfold higher density of mercury, the required NAPL entry heads of 6.19cm and 12.51cm for mercury to infiltrate were 37.5% to 20.7% lower than for PCE for the same porous media. Although Leverett scaling was able to reproduce the natural tendency of Hg 0 to be more prone than PCE to infiltrate in water saturated porous media, it considerably underestimated Hg 0 infiltration capacity in comparison with the experimental results. In the partially water saturated system, in contrast with PCE, elemental mercury also acted as a nonwetting fluid, therefore having to overcome an entry head to infiltrate. The required Hg 0 entry heads (10.45 and 15.74cm) were considerably higher (68.9% and 25.8%) than for the water saturated porous systems. Furthermore, in the partially water saturated systems, experiments showed that elemental mercury displaced both air and water, depending on the initial water distribution within the pores. This indicates that the conventional wettability hierarchy, in which the NAPL has an intermediate wetting state between the air and the water phases, is not valid for liquid elemental mercury. Therefore, for future modelling of elemental mercury DNAPL infiltration behaviour in variably water saturated porous media, a different formulation of the governing constitutive relations will be required. Copyright © 2018 Elsevier B.V. All rights reserved.

Wideband analytical equivalent circuit for one-dimensional periodic stacked arrays.

PubMed

Molero, Carlos; Rodríguez-Berral, Raúl; Mesa, Francisco; Medina, Francisco; Yakovlev, Alexander B

2016-01-01

A wideband equivalent circuit is proposed for the accurate analysis of scattering from a set of stacked slit gratings illuminated by a plane wave with transverse magnetic or electric polarization that impinges normally or obliquely along one of the principal planes of the structure. The slit gratings are printed on dielectric slabs of arbitrary thickness, including the case of closely spaced gratings that interact by higher-order modes. A Π-circuit topology is obtained for a pair of coupled arrays, with fully analytical expressions for all the circuit elements. This equivalent Π circuit is employed as the basis to derive the equivalent circuit of finite stacks with any given number of gratings. Analytical expressions for the Brillouin diagram and the Bloch impedance are also obtained for infinite periodic stacks.

Lumped-parameters equivalent circuit for condenser microphones modeling.

PubMed

Esteves, Josué; Rufer, Libor; Ekeom, Didace; Basrour, Skandar

2017-10-01

This work presents a lumped parameters equivalent model of condenser microphone based on analogies between acoustic, mechanical, fluidic, and electrical domains. Parameters of the model were determined mainly through analytical relations and/or finite element method (FEM) simulations. Special attention was paid to the air gap modeling and to the use of proper boundary condition. Corresponding lumped-parameters were obtained as results of FEM simulations. Because of its simplicity, the model allows a fast simulation and is readily usable for microphone design. This work shows the validation of the equivalent circuit on three real cases of capacitive microphones, including both traditional and Micro-Electro-Mechanical Systems structures. In all cases, it has been demonstrated that the sensitivity and other related data obtained from the equivalent circuit are in very good agreement with available measurement data.

Holographic Plossl Retroreflectors

NASA Technical Reports Server (NTRS)

Waluschka, Eugene

2006-01-01

Holographic retroreflectors that function equivalently to Plossl eyepieces have been developed and used in free-space optical communication systems that utilize laser beams. Plossl eyepieces are well known among telescope designers. They have been adopted for use a retroreflectors and as focusing elements (for reception) and collimating elements (for transmission) in optical communication systems. A retro-reflector that incorporates a Plossl eyepiece is termed a cat's-eye retroreflector.

Symmetry considerations in the scattering of identical composite bodies

NASA Technical Reports Server (NTRS)

Norbury, J. W.; Townsend, L. W.; Deutchman, P. A.

1986-01-01

Previous studies of the interactions between composite particles were extended to the case in which the composites are identical. The form of the total interaction potential matrix elements was obtained, and guidelines for their explicit evaluation were given. For the case of elastic scattering of identical composites, the matrix element approach was shown to be equivalent to the scattering amplitude method.

Dictionnaire contextuel anglais-francais de l'energie solaire (Contextual English-French Dictionary on Solar Energy).

ERIC Educational Resources Information Center

Serre, Robert

This English-French dictionary on solar energy is intended for translators and purports to contain all the elements necessary for doing quality translations. Each entry contains the following elements: (1) the basic English word with its synonyms and equivalents; (2) the definition in English and reference to its source; and (3) sentences or…

Energy Finite Element Analysis Developments for Vibration Analysis of Composite Aircraft Structures

NASA Technical Reports Server (NTRS)

Vlahopoulos, Nickolas; Schiller, Noah H.

2011-01-01

The Energy Finite Element Analysis (EFEA) has been utilized successfully for modeling complex structural-acoustic systems with isotropic structural material properties. In this paper, a formulation for modeling structures made out of composite materials is presented. An approach based on spectral finite element analysis is utilized first for developing the equivalent material properties for the composite material. These equivalent properties are employed in the EFEA governing differential equations for representing the composite materials and deriving the element level matrices. The power transmission characteristics at connections between members made out of non-isotropic composite material are considered for deriving suitable power transmission coefficients at junctions of interconnected members. These coefficients are utilized for computing the joint matrix that is needed to assemble the global system of EFEA equations. The global system of EFEA equations is solved numerically and the vibration levels within the entire system can be computed. The new EFEA formulation for modeling composite laminate structures is validated through comparison to test data collected from a representative composite aircraft fuselage that is made out of a composite outer shell and composite frames and stiffeners. NASA Langley constructed the composite cylinder and conducted the test measurements utilized in this work.

Sound transmission analysis of partially treated MR fluid-based sandwich panels using finite element method

NASA Astrophysics Data System (ADS)

Hemmatian, M.; Sedaghati, R.

2017-04-01

This study aims at developing a finite element model to predict the sound transmission loss (STL) of a multilayer panel partially treated with a Magnetorheological (MR) fluid core layer. MR fluids are smart materials with promising controllable rheological characteristics in which the application of an external magnetic field instantly changes their rheological properties. Partial treatment of sandwich panels with MR fluid core layer provides an opportunity to change stiffness and damping of the structure without significantly increasing the mass. The STL of a finite sandwich panel partially treated with MR fluid is modeled using the finite element (FE) method. Circular sandwich panels with clamped boundary condition and elastic face sheets in which the core layer is segmented circumferentially is considered. The MR fluid core layer is considered as a viscoelastic material with complex shear modulus with the magnetic field and frequency dependent storage and loss moduli. Neglecting the effect of the panel's vibration on the pressure forcing function, the work done by the acoustic pressure is expressed as a function of the blocked pressure in order to calculate the force vector in the equation of the motion of the panel. The governing finite element equation of motion of the MR sandwich panel is then developed to predict the transverse vibration of the panel which can then be utilized to obtain the radiated sound using Green's function. The developed model is used to conduct a systematic parametric study on the effect of different locations of MR fluid treatment on the natural frequencies and the STL.

A Survey of Removable Partial Denture (RPD) Retentive Elements in Relation to the Type of Edentulism and Abutment Teeth Found in Commercial Laboratories, Athens, Greece

PubMed Central

Sotiriou, Michael; Zissis, Alcibiades

2014-01-01

Objective The aim of this survey was to record removable partial denture (RPD) retentive elements and abutment teeth in partially edentulous patients, identified in commercial laboratories in Athens, Greece. Material and Methods 628 master casts with the corresponding cast metal frameworks used in the construction of RPDs were evaluated. Casts were photographed to identify the number and position of existing teeth, the partial edentulism class and the retentive elements. Prevalence tables and the x2 test were used for the statistical analysis of the collected data (α=.05). Results There were 276 maxillary (43.9%) and 352 (56.1%) mandibular casts. Maxillary edentulism entailed almost a total absence of right third molars in 96.7% and left third molars 96.0% of casts, with lower rates for the first and second molars. Edentulism in the posterior mandible presented a similar pattern. The most profound findings concerning retentive elements were: 91.9% of the retainers used were clasps and the remaining 8.1% were attachments. Of the clasps used, 48.9% were of the Roach Τ type, a finding more common in Kennedy Class I as compared to other Kennedy Classes (p<0.01). The circumferential clasps accounted for 19.3% of the total clasps used, and it was less frequently presented (8.8%) in Kennedy I Classes (p<0.01). Conclusions Roach clasps were used in the majority of cases whereas RPI clasps and attachments were rarely used. PMID:27688367

Charge-injection-device 2 x 64 element infrared array performance

NASA Technical Reports Server (NTRS)

Mckelvey, M. E.; Mccreight, C. R.; Goebel, J. H.; Reeves, A. A.

1985-01-01

Three 2 x 64 element Si:Bi accumulation-mode charge-injection-device (CID) arrays were tested at low and moderate background to evaluate their usefulness for space-based astronomical observations. Testing was conducted both in the laboratory and in ground-based telescope IR observations. The devices showed an average readout noise level below 200 equivalent electrons, a peak responsivity of 4 A/W, and a noise equivalent power of 3 x 10 to the -17th W/sq rt Hz. This sensitivity compares well with that of nonintegrating discrete extrinsic silicon photoconductors. The array well capacity was significantly smaller than predicted. The measured sensitivity makes extrinsic silicon CID arrays useful for certain astronomical applications. However, their readout efficiency and frequency response represent serious limitations in low-background applications.

Endurance and failure characteristics of modified Vasco X-2, CBS 600 and AISI 9310 spur gears. [aircraft construction materials

NASA Technical Reports Server (NTRS)

Townsend, D. P.; Zaretsky, E. V.

1980-01-01

Gear endurance tests and rolling-element fatigue tests were conducted to compare the performance of spur gears made from AISI 9310, CBS 600 and modified Vasco X-2 and to compare the pitting fatigue lives of these three materials. Gears manufactured from CBS 600 exhibited lives longer than those manufactured from AISI 9310. However, rolling-element fatigue tests resulted in statistically equivalent lives. Modified Vasco X-2 exhibited statistically equivalent lives to AISI 9310. CBS 600 and modified Vasco X-2 gears exhibited the potential of tooth fracture occurring at a tooth surface fatigue pit. Case carburization of all gear surfaces for the modified Vasco X-2 gears results in fracture at the tips of the gears.

A lattice Boltzmann model with an amending function for simulating nonlinear partial differential equations

NASA Astrophysics Data System (ADS)

Chen, Lin-Jie; Ma, Chang-Feng

2010-01-01

This paper proposes a lattice Boltzmann model with an amending function for one-dimensional nonlinear partial differential equations (NPDEs) in the form ut + αuux + βunux + γuxx + δuxxx + ζuxxxx = 0. This model is different from existing models because it lets the time step be equivalent to the square of the space step and derives higher accuracy and nonlinear terms in NPDEs. With the Chapman-Enskog expansion, the governing evolution equation is recovered correctly from the continuous Boltzmann equation. The numerical results agree well with the analytical solutions.

SPHERICAL DIE

DOEpatents

Livingston, J.P.

1959-01-27

A die is presented for pressing powdered materials into a hemispherical shape of uniforin density and wall thickness comprising a fcmale and male die element held in a stationary spaced relation with the space being equivalent to the wall thickness and defining the hemispherical shape, a pressing ring linearly moveable along the male die element, an inlet to fill the space with powdered materials, a guiding system for moving the pressing ring along the male die element so as to press the powdered material and a heating system for heating the male element so that the powdered material is heated while being pressed.

Boundary element analysis of post-tensioned slabs

NASA Astrophysics Data System (ADS)

Rashed, Youssef F.

2015-06-01

In this paper, the boundary element method is applied to carry out the structural analysis of post-tensioned flat slabs. The shear-deformable plate-bending model is employed. The effect of the pre-stressing cables is taken into account via the equivalent load method. The formulation is automated using a computer program, which uses quadratic boundary elements. Verification samples are presented, and finally a practical application is analyzed where results are compared against those obtained from the finite element method. The proposed method is efficient in terms of computer storage and processing time as well as the ease in data input and modifications.

78 FR 72013 - Schedules of Controlled Substances: Placement of Perampanel into Schedule III

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-02

... was approved for marketing by the FDA as an adjunctive treatment of partial-onset seizures with or... Management and Budget (OMB) pursuant to section 3(d)(1) of Executive Order 12866 and the principles... small entity. Once generic equivalents are developed and approved for manufacturing and marketing, there...

Partial Row-Sums of Pascal's Triangle

ERIC Educational Resources Information Center

Ollerton, Richard L.

2007-01-01

Identities for many and varied combinations of binomial coefficients abound. Indeed, because of the wide range of interrelationships it is possible that a great deal of mathematical effort has been wasted in proving essentially equivalent formulae. As well as proving identities these methods can be used to rule out closed form solutions (at least…

Birchwood biochar as partial carbon black replacement in styrene-butadiene rubber composites

USDA-ARS?s Scientific Manuscript database

Birchwood feedstock was used to make slow pyrolysis biochar that contained 89% carbon and < 2% ash. This biochar was blended with carbon black as filler for styrene-butadiene rubber. Composites made from blended fillers of 25/75 biochar/carbon black were equivalent to or superior to their 100% carbo...

Protective measurement of the wave function of a single squeezed harmonic-oscillator state

NASA Astrophysics Data System (ADS)

Alter, Orly; Yamamoto, Yoshihisa

1996-05-01

A scheme for the "protective measurement"

Modelling and structural analysis of skull/cranial implant: beyond mid-line deformities.

PubMed

Bogu, V Phanindra; Kumar, Y Ravi; Kumar Khanara, Asit

2017-01-01

This computational study explores modelling and finite element study of the implant under Intracranial pressure (ICP) conditions with normal ICP range (7 mm Hg to 15 mm Hg) or increased ICP (>I5 mm Hg). The implant fixation points allow implant behaviour with respect to intracranial pressure conditions. However, increased fixation points lead to variation in deformation and equivalent stress. Finite element analysis is providing a valuable insight to know the deformation and equivalent stress. The patient CT data (Computed Tomography) is processed in Mimics software to get the mesh model. The implant is modelled by using modified reverse engineering technique with the help of Rhinoceros software. This modelling method is applicable for all types of defects including those beyond the middle line and multiple ones. It is designed with eight fixation points and ten fixation points to fix an implant. Consequently, the mechanical deformation and equivalent stress (von Mises) are calculated in ANSYS 15 software with distinctive material properties such as Titanium alloy (Ti6Al4V), Polymethyl methacrylate (PMMA) and polyether-ether-ketone (PEEK). The deformation and equivalent stress results are obtained through ANSYS 15 software. It is observed that Ti6Al4V material shows low deformation and PEEK material shows less equivalent stress. Among all materials PEEK shows noticeably good result. Hence, a concept was established and more clinically relevant results can be expected with implementation of realistic 3D printed model in the future. This will allow physicians to gain knowledge and decrease surgery time with proper planning.

Robot-assisted laparoscopic partial nephrectomy versus laparoscopic partial nephrectomy: A propensity score-matched comparative analysis of surgical outcomes and preserved renal parenchymal volume.

PubMed

Tachibana, Hidekazu; Takagi, Toshio; Kondo, Tsunenori; Ishida, Hideki; Tanabe, Kazunari

2018-04-01

To compare surgical outcomes, including renal function and the preserved renal parenchymal volume, between robot-assisted laparoscopic partial nephrectomy and laparoscopic partial nephrectomy using propensity score-matched analyses. In total, 253 patients, with a normal contralateral kidney, who underwent laparoscopic partial nephrectomy (n = 131) or robot-assisted laparoscopic partial nephrectomy (n = 122) with renal arterial clamping between 2010 and 2015, were included. Patients' background and tumor factors were adjusted by propensity score matching. Surgical outcomes, including postoperative renal function, complications, warm ischemia time and preserved renal parenchymal volume, evaluated by volumetric analysis, were compared between the surgical procedures. After matching, 64 patients were assigned to each group. The mean age was 56-57 years, and the mean tumor size was 22 mm. Approximately 50% of patients had low complexity tumors (RENAL nephrometry score 4-7). The incidence rate of acute kidney failure was significantly lower in the robot-assisted laparoscopic partial nephrectomy (11%) than laparoscopic partial nephrectomy (23%) group (P = 0.049), and warm ischemia time shorter in the robot-assisted laparoscopic partial nephrectomy (17 min) than laparoscopic partial nephrectomy (25 min) group (P < 0.0001). The preservation rate of renal function, measured by the estimated glomerular filtration rate, at 6 months post-surgery was 96% for robot-assisted laparoscopic partial nephrectomy and 90% for laparoscopic partial nephrectomy (P < 0.0001). The preserved renal parenchymal volume was higher for robot-assisted laparoscopic partial nephrectomy (89%) than laparoscopic partial nephrectomy (77%; P < 0.0001). The rate of perioperative complications, surgical margin status and length of hospital stay were equivalent for both techniques. Robot-assisted laparoscopic partial nephrectomy allows to achieve better preservation of renal function and parenchymal volume than laparoscopic partial nephrectomy. © 2018 The Japanese Urological Association.

Insights into the chemical composition of the metal-poor Milky Way halo globular cluster NGC 6426

NASA Astrophysics Data System (ADS)

Hanke, M.; Koch, A.; Hansen, C. J.; McWilliam, A.

2017-03-01

We present our detailed spectroscopic analysis of the chemical composition of four red giant stars in the halo globular cluster NGC 6426. We obtained high-resolution spectra using the Magellan2/MIKE spectrograph, from which we derived equivalent widths and subsequently computed abundances of 24 species of 22 chemical elements. For the purpose of measuring equivalent widths, we developed a new semi-automated tool, called EWCODE. We report a mean Fe content of [Fe/H] =-2.34 ± 0.05 dex (stat.) in accordance with previous studies. At a mean α-abundance of [(Mg, Si, Ca)/3 Fe] = 0.39 ± 0.03 dex, NGC 6426 falls on the trend drawn by the Milky Way halo and other globular clusters at comparably low metallicities. The distribution of the lighter α-elements as well as the enhanced ratio [Zn/Fe] = 0.39 dex could originate from hypernova enrichment of the pre-cluster medium. We find tentative evidence for a spread in the elements Mg, Si, and Zn, indicating an enrichment scenario, where ejecta of evolved massive stars of a slightly older population have polluted a newly born younger one. The heavy element abundances in this cluster fit well into the picture of metal-poor globular clusters, which in that respect appear to be remarkably homogeneous. The pattern of the neutron-capture elements heavier than Zn points toward an enrichment history governed by the r-process with little, if any, sign of s-process contributions. This finding is supported by the striking similarity of our program stars to the metal-poor field star HD 108317. This paper includes data gathered with the 6.5-m Magellan Telescopes located at Las Campanas Observatory, Chile.Equivalent widths and full Table 2 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/599/A97

Structural analysis of natural textures.

PubMed

Vilnrotter, F M; Nevatia, R; Price, K E

1986-01-01

Many textures can be described structurally, in terms of the individual textural elements and their spatial relationships. This paper describes a system to generate useful descriptions of natural textures in these terms. The basic approach is to determine an initial, partial description of the elements using edge features. This description controls the extraction of the texture elements. The elements are grouped by type, and spatial relationships between elements are computed. The descriptions are shown to be useful for recognition of the textures, and for reconstruction of periodic textures.

Probabilistic Structures Analysis Methods (PSAM) for select space propulsion system components

NASA Technical Reports Server (NTRS)

1991-01-01

The basic formulation for probabilistic finite element analysis is described and demonstrated on a few sample problems. This formulation is based on iterative perturbation that uses the factorized stiffness on the unperturbed system as the iteration preconditioner for obtaining the solution to the perturbed problem. This approach eliminates the need to compute, store and manipulate explicit partial derivatives of the element matrices and force vector, which not only reduces memory usage considerably, but also greatly simplifies the coding and validation tasks. All aspects for the proposed formulation were combined in a demonstration problem using a simplified model of a curved turbine blade discretized with 48 shell elements, and having random pressure and temperature fields with partial correlation, random uniform thickness, and random stiffness at the root.

Melt-Vapor Phase Diagram of the Te-S System

NASA Astrophysics Data System (ADS)

Volodin, V. N.; Trebukhov, S. A.; Kenzhaliyev, B. K.; Nitsenko, A. V.; Burabaeva, N. M.

2018-03-01

The values of partial pressure of saturated vapor of the constituents of the Te-S system are determined from boiling points. The boundaries of the melt-vapor phase transition at atmospheric pressure and in vacuum of 2000 and 100 Pa are calculated on the basis of partial pressures. A phase diagram that includes vapor-liquid equilibrium fields whose boundaries allow us to assess the behavior of elements upon distillation fractioning is plotted. It is established that the separation of elements is possible at the first evaporation-condensation cycle. Complications can be caused by crystallization of a sulfur solid solution in tellurium.

Structural Stabilities of β-Ti Alloys Studied Using a New Mo Equivalent Derived from [ β/( α + β)] Phase-Boundary Slopes

NASA Astrophysics Data System (ADS)

Wang, Qing; Dong, Chuang; Liaw, Peter K.

2015-08-01

Structural stabilities of β-Ti alloys are generally investigated by an empirical Mo equivalent, which quantifies the stability contribution of each alloying element, M, in comparison to that of the major β-Ti stabilizer, Mo. In the present work, a new Mo equivalent (Moeq)Q is proposed, which uses the slopes of the boundary lines between the β and ( α + β) phase zones in binary Ti-M phase diagrams. This (Moeq)Q reflects a simple fact that the β-Ti stability is enhanced, when the β phase zone is enlarged by a β-Ti stabilizer. It is expressed as (Moeq)Q = 1.0 Mo + 0.74 V + 1.01 W + 0.23 Nb + 0.30 Ta + 1.23 Fe + 1.10 Cr + 1.09 Cu + 1.67 Ni + 1.81 Co + 1.42 Mn + 0.38 Sn + 0.34 Zr + 0.99 Si - 0.57 Al (at. pct), where the equivalent coefficient of each element is the slope ratio of the [ β/( α + β)] boundary line of the binary Ti-M phase diagram to that of the Ti-Mo. This (Moeq)Q is shown to reliably characterize the critical stability limit of multi-component β-Ti alloys with low Young's moduli, where the critical lower limit for β stabilization is (Moeq)Q = 6.25 at. pct or 11.8 wt pct Mo.

[Analysis of stress in periodontal ligament of the maxillary first molar on distal movement by nonlinear finite element method].

PubMed

Dong, Jing; Zhang, Zhe-chen; Zhou, Guo-liang

2015-06-01

To analyze the stress distribution in periodontal ligament of maxillary first molar during distal movement with nonlinear finite element analysis, and to compare it with the result of linear finite element analysis, consequently to provide biomechanical evidence for clinical application. The 3-D finite element model including a maxillary first molar, periodontal ligament, alveolar bone, cancellous bone, cortical bone and a buccal tube was built up by using Mimics, Geomagic, ProE and Ansys Workbench. The material of periodontal ligament was set as nonlinear material and linear elastic material, respectively. Loads of different combinations were applied to simulate the clinical situation of distalizing the maxillary first molar. There were channels of low stress in peak distribution of Von Mises equivalent stress and compressive stress of periodontal ligament in nonlinear finite element model. The peak of Von Mises equivalent stress was lower when it was satisfied that Mt/F minus Mr/F approximately equals 2. The peak of compressive stress was lower when it was satisfied that Mt/F was approximately equal to Mr/F. The relative stress of periodontal ligament was higher and violent in linear finite element model and there were no channels of low stress in peak distribution. There are channels in which stress of periodontal ligament is lower. The condition of low stress should be satisfied by applied M/F during the course of distalizing the maxillary first molar.

Calculation of the Full Scattering Amplitude without Partial Wave Decomposition II

NASA Technical Reports Server (NTRS)

Shertzer, J.; Temkin, A.

2003-01-01

As is well known, the full scattering amplitude can be expressed as an integral involving the complete scattering wave function. We have shown that the integral can be simplified and used in a practical way. Initial application to electron-hydrogen scattering without exchange was highly successful. The Schrodinger equation (SE) can be reduced to a 2d partial differential equation (pde), and was solved using the finite element method. We have now included exchange by solving the resultant SE, in the static exchange approximation. The resultant equation can be reduced to a pair of coupled pde's, to which the finite element method can still be applied. The resultant scattering amplitudes, both singlet and triplet, as a function of angle can be calculated for various energies. The results are in excellent agreement with converged partial wave results.

Partial melting of amphibolite to trondhjemite near Ykutat, Alaska

NASA Technical Reports Server (NTRS)

Barker, F.

1986-01-01

At Nunatak Fiord, 55 km NE of Yakutat, Alaska, a uniform layer of Cretaceous metabasalt approximately 3 km thick was metamorphosed to amphibolite facies and locally partially melted to trondhjemite pegmatite. Results of the rare earth element analysis performed on the amphibolite and the trondhjemite pegmatite are discussed.

Rotor-to-stator Partial Rubbing and Its Effects on Rotor Dynamic Response

NASA Technical Reports Server (NTRS)

Muszynska, Agnes; Franklin, Wesley D.; Hayashida, Robert D.

1991-01-01

Results from experimental and analytical studies on rotor to stationary element partial rubbings at several locations and their effects on rotor dynamic responses are presented. The mathematical model of a rubbing rotor is given. The computer program provides numerical results which agree with experimentally obtained rotor responses.

Optimization of sparse synthetic transmit aperture imaging with coded excitation and frequency division.

PubMed

Behar, Vera; Adam, Dan

2005-12-01

An effective aperture approach is used for optimization of a sparse synthetic transmit aperture (STA) imaging system with coded excitation and frequency division. A new two-stage algorithm is proposed for optimization of both the positions of the transmit elements and the weights of the receive elements. In order to increase the signal-to-noise ratio in a synthetic aperture system, temporal encoding of the excitation signals is employed. When comparing the excitation by linear frequency modulation (LFM) signals and phase shift key modulation (PSKM) signals, the analysis shows that chirps are better for excitation, since at the output of a compression filter the sidelobes generated are much smaller than those produced by the binary PSKM signals. Here, an implementation of a fast STA imaging is studied by spatial encoding with frequency division of the LFM signals. The proposed system employs a 64-element array with only four active elements used during transmit. The two-dimensional point spread function (PSF) produced by such a sparse STA system is compared to the PSF produced by an equivalent phased array system, using the Field II simulation program. The analysis demonstrates the superiority of the new sparse STA imaging system while using coded excitation and frequency division. Compared to a conventional phased array imaging system, this system acquires images of equivalent quality 60 times faster, when the transmit elements are fired in pairs consecutively and the power level used during transmit is very low. The fastest acquisition time is achieved when all transmit elements are fired simultaneously, which improves detectability, but at the cost of a slight degradation of the axial resolution. In real-time implementation, however, it must be borne in mind that the frame rate of a STA imaging system depends not only on the acquisition time of the data but also on the processing time needed for image reconstruction. Comparing to phased array imaging, a significant increase in the frame rate of a STA imaging system is possible if and only if an equivalent time efficient algorithm is used for image reconstruction.

Evaluation of Exposure From a Low Energy X-Ray Device Using Thermoluminescent Dosimeters

NASA Technical Reports Server (NTRS)

Edwards, David L.; Harris, William S., Jr.

1997-01-01

The exposure from an electron beam welding device was evaluated using thermoluminescent dosimeters (TLDs). The device generated low energy X-rays which the current dose equivalent conversion algorithm was not designed to evaluate making it necessary to obtain additional information relating to TLD operation at the photon energies encountered with the device. This was accomplished by performing irradiations at the National Institute of Standards and Technology (NIST) using low energy X-ray techniques. The resulting data was used to determine TLD badge response for low energy X-rays and to establish the relationship between TLD element response and the dose equivalent at specific depths in tissue for these photon energies. The new energy/dose equivalent calibration data was used to calculate the shallow and eye dose equivalent of badges exposed to the device.

Sub-millimeter-Wave Equivalent Circuit Model for External Parasitics in Double-Finger HEMT Topologies

NASA Astrophysics Data System (ADS)

Karisan, Yasir; Caglayan, Cosan; Sertel, Kubilay

2018-02-01

We present a novel distributed equivalent circuit that incorporates a three-way-coupled transmission line to accurately capture the external parasitics of double-finger high electron mobility transistor (HEMT) topologies up to 750 GHz. A six-step systematic parameter extraction procedure is used to determine the equivalent circuit elements for a representative device layout. The accuracy of the proposed approach is validated in the 90-750 GHz band through comparisons between measured data (via non-contact probing) and full-wave simulations, as well as the equivalent circuit response. Subsequently, a semi-distributed active device model is incorporated into the proposed parasitic circuit to demonstrate that the three-way-coupled transmission line model effectively predicts the adverse effect of parasitic components on the sub-mmW performance in an amplifier setting.

A partially penalty immersed Crouzeix-Raviart finite element method for interface problems.

PubMed

An, Na; Yu, Xijun; Chen, Huanzhen; Huang, Chaobao; Liu, Zhongyan

2017-01-01

The elliptic equations with discontinuous coefficients are often used to describe the problems of the multiple materials or fluids with different densities or conductivities or diffusivities. In this paper we develop a partially penalty immersed finite element (PIFE) method on triangular grids for anisotropic flow models, in which the diffusion coefficient is a piecewise definite-positive matrix. The standard linear Crouzeix-Raviart type finite element space is used on non-interface elements and the piecewise linear Crouzeix-Raviart type immersed finite element (IFE) space is constructed on interface elements. The piecewise linear functions satisfying the interface jump conditions are uniquely determined by the integral averages on the edges as degrees of freedom. The PIFE scheme is given based on the symmetric, nonsymmetric or incomplete interior penalty discontinuous Galerkin formulation. The solvability of the method is proved and the optimal error estimates in the energy norm are obtained. Numerical experiments are presented to confirm our theoretical analysis and show that the newly developed PIFE method has optimal-order convergence in the [Formula: see text] norm as well. In addition, numerical examples also indicate that this method is valid for both the isotropic and the anisotropic elliptic interface problems.

Modelling alkali metal emissions in large-eddy simulation of a preheated pulverised-coal turbulent jet flame using tabulated chemistry

NASA Astrophysics Data System (ADS)

Wan, Kaidi; Xia, Jun; Vervisch, Luc; Liu, Yingzu; Wang, Zhihua; Cen, Kefa

2018-03-01

The numerical modelling of alkali metal reacting dynamics in turbulent pulverised-coal combustion is discussed using tabulated sodium chemistry in large eddy simulation (LES). A lookup table is constructed from a detailed sodium chemistry mechanism including five sodium species, i.e. Na, NaO, NaO2, NaOH and Na2O2H2, and 24 elementary reactions. This sodium chemistry table contains four coordinates, i.e. the equivalence ratio, the mass fraction of the sodium element, the gas-phase temperature, and a progress variable. The table is first validated against the detailed sodium chemistry mechanism by zero-dimensional simulations. Then, LES of a turbulent pulverised-coal jet flame is performed and major coal-flame parameters compared against experiments. The chemical percolation devolatilisation (CPD) model and the partially stirred reactor (PaSR) model are employed to predict coal pyrolysis and gas-phase combustion, respectively. The response of the five sodium species in the pulverised-coal jet flame is subsequently examined. Finally, a systematic global sensitivity analysis of the sodium lookup table is performed and the accuracy of the proposed tabulated sodium chemistry approach has been calibrated.

Trajectory-based modeling of fluid transport in a medium with smoothly varying heterogeneity

DOE PAGES

Vasco, D. W.; Pride, Steven R.; Commer, Michael

2016-03-04

Using an asymptotic methodology, valid in the presence of smoothly varying heterogeneity and prescribed boundaries, we derive a trajectory-based solution for tracer transport. The analysis produces a Hamilton-Jacobi partial differential equation for the phase of the propagating tracer front. The trajectories follow from the characteristic equations that are equivalent to the Hamilton-Jacobi equation. The paths are determined by the fluid velocity field, the total porosity, and the dispersion tensor. Due to their dependence upon the local hydrodynamic dispersion, they differ from conventional streamlines. This difference is borne out in numerical calculations for both uniform and dipole flow fields. In anmore » application to the computational X-ray imaging of a saline tracer test, we illustrate that the trajectories may serve as the basis for a form of tracer tomography. In particular, we use the onset time of a change in attenuation for each volume element of the X-ray image as a measure of the arrival time of the saline tracer. In conclusion, the arrival times are used to image the spatial variation of the effective hydraulic conductivity within the laboratory sample.« less

Experimental investigation on circumferential and axial temperature gradient over fuel channel under LOCA

NASA Astrophysics Data System (ADS)

Yadav, Ashwini Kumar; kumar, Ravi; Gupta, Akhilesh; Chatterjee, Barun; Mukhopadhyay, Deb; Lele, H. G.

2014-06-01

In a nuclear reactor temperature rises drastically in fuel channels under loss of coolant accident due to failure of primary heat transportation system. Present investigation has been carried out to capture circumferential and axial temperature gradients during fully and partially voiding conditions in a fuel channel using 19 pin fuel element simulator. A series of experiments were carried out by supplying power to outer, middle and center rods of 19 pin fuel simulator in ratio of 1.4:1.1:1. The temperature at upper periphery of pressure tube (PT) was slightly higher than at bottom due to increase in local equivalent thermal conductivity from top to bottom of PT. To simulate fully voided conditions PT was pressurized at 2.0 MPa pressure with 17.5 kW power injection. Ballooning initiated from center and then propagates towards the ends and hence axial temperature difference has been observed along the length of PT. For asymmetric heating, upper eight rods of fuel simulator were activated and temperature difference up-to 250 °C has been observed from top to bottom periphery of PT. Such situation creates steep circumferential temperature gradient over PT and could lead to breaching of PT under high pressure.

Nongeneric positive partial transpose states of rank five in 3×3 dimensions

NASA Astrophysics Data System (ADS)

Hansen, Leif Ove; Myrheim, Jan

In 3×3 dimensions, entangled mixed states that are positive under partial transposition (PPT states) must have rank at least four. These rank four states are completely understood. We say that they have rank (4,4) since both a state ρ and its partial transpose ρP have rank four. The next problem is to understand the extremal PPT states of rank (5,5). We call two states SL⊗SL-equivalent if they are related by a product transformation. A generic rank (5,5) PPT state ρ is extremal, and both ρ and ρP have six product vectors in their ranges, and no product vectors in their kernels. The three numbers {6,6;0} are SL⊗SL-invariants that help us classify the state. There is no analytical understanding of such states. We have studied numerically a few types of nongeneric rank five PPT states, in particular, states with one or more product vectors in their kernels. We find an interesting new analytical construction of all rank four extremal PPT states, up to SL⊗SL-equivalence, where they appear as boundary states on one single five-dimensional face on the set of normalized PPT states. The interior of the face consists of rank (5,5) states with four common product vectors in their kernels, it is a simplex of separable states surrounded by entangled PPT states. We say that a state ρ is SL⊗SL-symmetric if ρ and ρP are SL⊗SL-equivalent, and is genuinely SL⊗SL-symmetric if it is SL⊗SL-equivalent to a state τ with τ=τP. Genuine SL⊗SL-symmetry implies a special form of SL⊗SL-symmetry. We have produced numerically, by a special method, a random sample of rank (5,5) SL⊗SL-symmetric states. About 50 of these are of type {6,6;0}, among those all are extremal and about half are genuinely SL⊗SL-symmetric. All these genuinely SL⊗SL-symmetric states can be transformed to have a circulant form. We find however that this is not a generic property of genuinely SL⊗SL-symmetric states. The remaining SL⊗SL-symmetric states found in the search have product vectors in their kernels, and they inspired us to study such states without regard to SL⊗SL-symmetry.

Spontaneous cell sorting of fibroblasts and keratinocytes creates an organotypic human skin equivalent.

PubMed

Wang, C K; Nelson, C F; Brinkman, A M; Miller, A C; Hoeffler, W K

2000-04-01

We show that an inherent ability of two distinct cell types, keratinocytes and fibroblasts, can be relied upon to accurately reconstitute full-thickness human skin including the dermal-epidermal junction by a cell-sorting mechanism. A cell slurry containing both cell types added to silicone chambers implanted on the backs of severe combined immunodeficient mice sorts out to reconstitute a clearly defined dermis and stratified epidermis within 2 wk, forming a cell-sorted skin equivalent. Immunostaining of the cell-sorted skin equivalent with human cell markers showed patterns similar to those of normal full-thickness skin. We compared the cell-sorted skin equivalent model with a composite skin model also made on severe combined immunodeficient mice. The composite grafts were constructed from partially differentiated keratinocyte sheets placed on top of a dermal equivalent constructed of devitalized dermis. Electron microscopy revealed that both models formed ample numbers of normal appearing hemidesmosomes. The cell-sorted skin equivalent model, however, had greater numbers of keratin intermediate filaments within the basal keratinocytes that connected to hemidesmosomes, and on the dermal side both collagen filaments and anchoring fibril connections to the lamina densa were more numerous compared with the composite model. Our results may provide some insight into why, in clinical applications for treating burns and other wounds, composite grafts may exhibit surface instability and blistering for up to a year following grafting, and suggest the possible usefulness of the cell-sorted skin equivalent in future grafting applications.

Wind-chill-equivalent temperatures: regarding the impact due to the variability of the environmental convective heat transfer coefficient.

PubMed

Shitzer, Avraham

2006-03-01

The wind-chill index (WCI), developed in Antarctica in the 1940s and recently updated by the weather services in the USA and Canada, expresses the enhancement of heat loss in cold climates from exposed body parts, e.g., face, due to wind. The index provides a simple and practical means for assessing the thermal effects of wind on humans outdoors. It is also used for indicating weather conditions that may pose adverse risks of freezing at subfreezing environmental temperatures. Values of the WCI depend on a number of parameters, i.e, temperatures, physical properties of the air, wind speed, etc., and on insolation and evaporation. This paper focuses on the effects of various empirical correlations used in the literature for calculating the convective heat transfer coefficients between humans and their environment. Insolation and evaporation are not included in the presentation. Large differences in calculated values among these correlations are demonstrated and quantified. Steady-state wind-chill-equivalent temperatures (WCETs) are estimated by a simple, one-dimensional heat-conducting hollow-cylindrical model using these empirical correlations. Partial comparison of these values with the published "new" WCETs is presented. The variability of the estimated WCETs, due to different correlations employed to calculate them, is clearly demonstrated. The results of this study clearly suggest the need for establishing a "gold standard" for estimating convective heat exchange between exposed body elements and the cold and windy environment. This should be done prior to the introduction and adoption of further modifications to WCETs and indices. Correlations to estimate the convective heat transfer coefficients between exposed body parts of humans in windy and cold environments influence the WCETs and need to be standardized.

Wind-chill-equivalent temperatures: regarding the impact due to the variability of the environmental convective heat transfer coefficient

NASA Astrophysics Data System (ADS)

Shitzer, Avraham

2006-03-01

The wind-chill index (WCI), developed in Antarctica in the 1940s and recently updated by the weather services in the USA and Canada, expresses the enhancement of heat loss in cold climates from exposed body parts, e.g., face, due to wind. The index provides a simple and practical means for assessing the thermal effects of wind on humans outdoors. It is also used for indicating weather conditions that may pose adverse risks of freezing at subfreezing environmental temperatures. Values of the WCI depend on a number of parameters, i.e, temperatures, physical properties of the air, wind speed, etc., and on insolation and evaporation. This paper focuses on the effects of various empirical correlations used in the literature for calculating the convective heat transfer coefficients between humans and their environment. Insolation and evaporation are not included in the presentation. Large differences in calculated values among these correlations are demonstrated and quantified. Steady-state wind-chill-equivalent temperatures (WCETs) are estimated by a simple, one-dimensional heat-conducting hollow-cylindrical model using these empirical correlations. Partial comparison of these values with the published “new” WCETs is presented. The variability of the estimated WCETs, due to different correlations employed to calculate them, is clearly demonstrated. The results of this study clearly suggest the need for establishing a “gold standard” for estimating convective heat exchange between exposed body elements and the cold and windy environment. This should be done prior to the introduction and adoption of further modifications to WCETs and indices. Correlations to estimate the convective heat transfer coefficients between exposed body parts of humans in windy and cold environments influence the WCETs and need to be standardized.

Two novel elements (CFG1 and PYG1) of Mag lineage of Ty3/Gypsy retrotransposons from Zhikong scallop (Chlamys farreri) and Japanese scallop (Patinopecten yessoensis).

PubMed

Wang, Shi; Bao, Zhenmin; Hu, Xiaoli; Shao, Mingyu; Zhang, Lingling; Hu, Jingjie

2008-05-01

Two novel elements (CFG1 and PYG1) of Mag lineage of Ty3/Gypsy retrotransposons were cloned from Zhikong scallop (Chlamys farreri) and Japanese scallop (Patinopecten yessoensis). The total length of the CFG1 element is 4826 bp, including 5'-LTR (192 bp), the entire ORF (4047 bp) and 3'-LTR (189 bp). The entire ORFs of both CFG1 and PYG1 elements are composed of 1348 aa and do not have any frameshifts. Their closest relative is Jule element from the poeciliid fish (Xiphophorus maculatus). On average, the diploid genome of C. farreri contains approximately 84 copies of CFG1 elements. We summarize the major features of CFG1, PYG1 and other elements of Mag lineage of the Ty3/Gypsy group. mRNA expression of CFG1 element in larvae increases gradually before the gastrulae stage and decreases gradually afterward, whereas in adductor such expression in adductor muscle and digestive gland are lower than those in other tissues. Overall, mRNA expression of CFG1 element in the early larvae is significantly higher than that in adult tissues. In muscle tissue, while the promoter and partial GAG domain of CFG1 element are unmethylated, the partial RT domain is highly methylated. These results suggest that CFG1 expression may be controlled by a post-transcriptional gene silencing mechanism that is associated with coding-region (RT domain) methylation.

XFEM with equivalent eigenstrain for matrix-inclusion interfaces

NASA Astrophysics Data System (ADS)

Benvenuti, Elena

2014-05-01

Several engineering applications rely on particulate composite materials, and numerical modelling of the matrix-inclusion interface is therefore a crucial part of the design process. The focus of this work is on an original use of the equivalent eigenstrain concept in the development of a simplified eXtended Finite Element Method. Key points are: the replacement of the matrix-inclusion interface by a coating layer with small but finite thickness, and its simulation as an inclusion with an equivalent eigenstrain. For vanishing thickness, the model is consistent with a spring-like interface model. The problem of a spherical inclusion within a cylinder is solved. The results show that the proposed approach is effective and accurate.

School Finance Reform: Decoding the Simulation Maze

ERIC Educational Resources Information Center

Jargowsky, Peter; And Others

1977-01-01

Demonstrates the mathematical equivalence of various school finance equalization formulas, describes the elements that complicate the preparation of a generalized simulation capability, and briefly presents a conceptualization of a generalized simulation model. (JG)

Dielectric relaxation in AC powder electroluminescent devices

NASA Astrophysics Data System (ADS)

Zhang, Shuai; Su, Haibin; Tan, Chuan Seng; Wong, Terence Kin Shun; Teo, Ronnie Jin Wah

2017-01-01

The dielectric properties of AC powder electroluminescent devices were measured and analyzed using complex impedance spectroscopy to determine the relaxation processes occurring within the devices. The relaxation processes identified were ascribed to the electrode polarization caused by ion accumulation at the electrode/resin interfaces, the Maxwell-Wagner-Sillars effects at the (ZnS or BaTiO3) particle/resin interfaces, and the dipolar reorientation of polymer chains in the resin matrix. Each relaxation process was represented by its corresponding equivalent circuit component. Space charge polarization at the electrodes were represented by a Warburg element, a resistor, and a constant phase element. The resin matrix, ZnS/resin and BaTiO3/resin interfaces could each be modeled by a resistor and a capacitor in parallel. The simulated equivalent circuits for three different printed structures showed good fitting with their experimental impedance results.

Non-detonable and non-explosive explosive simulators

DOEpatents

Simpson, Randall L.; Pruneda, Cesar O.

1997-01-01

A simulator which is chemically equivalent to an explosive, but is not detonable or explodable. The simulator is a combination of an explosive material with an inert material, either in a matrix or as a coating, where the explosive has a high surface ratio but small volume ratio. The simulator has particular use in the training of explosives detecting dogs, calibrating analytical instruments which are sensitive to either vapor or elemental composition, or other applications where the hazards associated with explosives is undesirable but where chemical and/or elemental equivalence is required. The explosive simulants may be fabricated by different techniques. A first method involves the use of standard slurry coatings to produce a material with a very high binder to explosive ratio without masking the explosive vapor, and a second method involves coating inert substrates with thin layers of explosive.

Quantitative Modelling of Trace Elements in Hard Coal.

PubMed

Smoliński, Adam; Howaniec, Natalia

2016-01-01

The significance of coal in the world economy remains unquestionable for decades. It is also expected to be the dominant fossil fuel in the foreseeable future. The increased awareness of sustainable development reflected in the relevant regulations implies, however, the need for the development and implementation of clean coal technologies on the one hand, and adequate analytical tools on the other. The paper presents the application of the quantitative Partial Least Squares method in modeling the concentrations of trace elements (As, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Rb, Sr, V and Zn) in hard coal based on the physical and chemical parameters of coal, and coal ash components. The study was focused on trace elements potentially hazardous to the environment when emitted from coal processing systems. The studied data included 24 parameters determined for 132 coal samples provided by 17 coal mines of the Upper Silesian Coal Basin, Poland. Since the data set contained outliers, the construction of robust Partial Least Squares models for contaminated data set and the correct identification of outlying objects based on the robust scales were required. These enabled the development of the correct Partial Least Squares models, characterized by good fit and prediction abilities. The root mean square error was below 10% for all except for one the final Partial Least Squares models constructed, and the prediction error (root mean square error of cross-validation) exceeded 10% only for three models constructed. The study is of both cognitive and applicative importance. It presents the unique application of the chemometric methods of data exploration in modeling the content of trace elements in coal. In this way it contributes to the development of useful tools of coal quality assessment.

Quantitative Modelling of Trace Elements in Hard Coal

PubMed Central

Smoliński, Adam; Howaniec, Natalia

2016-01-01

The significance of coal in the world economy remains unquestionable for decades. It is also expected to be the dominant fossil fuel in the foreseeable future. The increased awareness of sustainable development reflected in the relevant regulations implies, however, the need for the development and implementation of clean coal technologies on the one hand, and adequate analytical tools on the other. The paper presents the application of the quantitative Partial Least Squares method in modeling the concentrations of trace elements (As, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Rb, Sr, V and Zn) in hard coal based on the physical and chemical parameters of coal, and coal ash components. The study was focused on trace elements potentially hazardous to the environment when emitted from coal processing systems. The studied data included 24 parameters determined for 132 coal samples provided by 17 coal mines of the Upper Silesian Coal Basin, Poland. Since the data set contained outliers, the construction of robust Partial Least Squares models for contaminated data set and the correct identification of outlying objects based on the robust scales were required. These enabled the development of the correct Partial Least Squares models, characterized by good fit and prediction abilities. The root mean square error was below 10% for all except for one the final Partial Least Squares models constructed, and the prediction error (root mean square error of cross–validation) exceeded 10% only for three models constructed. The study is of both cognitive and applicative importance. It presents the unique application of the chemometric methods of data exploration in modeling the content of trace elements in coal. In this way it contributes to the development of useful tools of coal quality assessment. PMID:27438794

Design of HIFU transducers for generating specified nonlinear ultrasound fields

PubMed Central

Rosnitskiy, Pavel B.; Yuldashev, Petr V.; Sapozhnikov, Oleg A.; Maxwell, Adam; Kreider, Wayne; Bailey, Michael R.; Khokhlova, Vera A.

2016-01-01

Various clinical applications of high intensity focused ultrasound (HIFU) have different requirements for the pressure levels and degree of nonlinear waveform distortion at the focus. The goal of this work was to determine transducer design parameters that produce either a specified shock amplitude in the focal waveform or specified peak pressures while still maintaining quasilinear conditions at the focus. Multi-parametric nonlinear modeling based on the KZK equation with an equivalent source boundary condition was employed. Peak pressures, shock amplitudes at the focus, and corresponding source outputs were determined for different transducer geometries and levels of nonlinear distortion. Results are presented in terms of the parameters of an equivalent single-element, spherically shaped transducer. The accuracy of the method and its applicability to cases of strongly focused transducers were validated by comparing the KZK modeling data with measurements and nonlinear full-diffraction simulations for a single-element source and arrays with 7 and 256 elements. The results provide look-up data for evaluating nonlinear distortions at the focus of existing therapeutic systems as well as for guiding the design of new transducers that generate specified nonlinear fields. PMID:27775904

Partially premixed prevalorized kerosene spray combustion in turbulent flow

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

Chrigui, M.; Ahmadi, W.; Sadiki, A.

2010-04-15

A detailed numerical simulation of kerosene spray combustion was carried out on a partially premixed, prevaporized, three-dimensional configuration. The focus was on the flame temperature profile dependency on the length of the pre-vaporization zone. The results were analyzed and compared to experimental data. A fundamental study was performed to observe the temperature variation and flame flashback. Changes were made to the droplet diameter, kerosene flammability limits, a combustion model parameter and the location of the combustion initialization. Investigations were performed for atmospheric pressure, inlet air temperature of 90 C and a global equivalence ratio of 0.7. The simulations were carriedmore » out using the Eulerian Lagrangian procedure under a fully two-way coupling. The Bray-Moss-Libby model was adjusted to account for the partially premixed combustion. (author)« less

Diffraction of an Electromagnetic Wave on a Dielectric Rod in a Rectangular Waveguide. A Method of Partial Waveguide Filling

NASA Astrophysics Data System (ADS)

Zav'yalov, A. S.

2018-04-01

A variant of the method of partial waveguide filling is considered in which a sample is put into a waveguide through holes in wide waveguide walls at the distance equal to a quarter of the wavelength in the waveguide from a short-circuiter, and the total input impedance of the sample in the waveguide is directly measured. The equivalent circuit of the sample is found both without and with account of the hole. It is demonstrated that consideration of the edge effect makes it possible to obtain more exact values of the dielectric permittivity.

White-light parametric instabilities in plasmas.

PubMed

Santos, J E; Silva, L O; Bingham, R

2007-06-08

Parametric instabilities driven by partially coherent radiation in plasmas are described by a generalized statistical Wigner-Moyal set of equations, formally equivalent to the full wave equation, coupled to the plasma fluid equations. A generalized dispersion relation for stimulated Raman scattering driven by a partially coherent pump field is derived, revealing a growth rate dependence, with the coherence width sigma of the radiation field, scaling with 1/sigma for backscattering (three-wave process), and with 1/sigma1/2 for direct forward scattering (four-wave process). Our results demonstrate the possibility to control the growth rates of these instabilities by properly using broadband pump radiation fields.

Cold air performance of a tip turbine designed to drive a lift fan. 2: Partial admission

NASA Technical Reports Server (NTRS)

Haas, J. E.; Kofskey, M. G.; Hotz, G. M.; Futral, S. M., Jr.

1977-01-01

Partial admission performance was obtained for a 0.4 linear scale version of the LF460 lift fan turbine over a range of speed from 40 to 140 percent of design equivalent speed and a range of scroll inlet total to diffuser exit static pressure ratio from 2.2 to 5.0. The investigation was conducted in two parts, with each part using a different side of the turbine scroll to simulate loss of a gas generator. Each side had an arc of admission of 180. Results are presented in terms of specific work, torque, mass flow, and efficiency.

Reference Models for Multi-Layer Tissue Structures

DTIC Science & Technology

2016-09-01

simulation,  finite   element  analysis 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON USAMRMC...Physiologically realistic, fully specimen-specific, nonlinear reference models. Tasks. Finite element analysis of non-linear mechanics of cadaver...models. Tasks. Finite element analysis of non-linear mechanics of multi-layer tissue regions of human subjects. Deliverables. Partially subject- and

Parallel Element Agglomeration Algebraic Multigrid and Upscaling Library

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

Barker, Andrew T.; Benson, Thomas R.; Lee, Chak Shing

ParELAG is a parallel C++ library for numerical upscaling of finite element discretizations and element-based algebraic multigrid solvers. It provides optimal complexity algorithms to build multilevel hierarchies and solvers that can be used for solving a wide class of partial differential equations (elliptic, hyperbolic, saddle point problems) on general unstructured meshes. Additionally, a novel multilevel solver for saddle point problems with divergence constraint is implemented.

A novel analytical description of periodic volume coil geometries in MRI

NASA Astrophysics Data System (ADS)

Koh, D.; Felder, J.; Shah, N. J.

2018-03-01

MRI volume coils can be represented by equivalent lumped element circuits and for a variety of these circuit configurations analytical design equations have been presented. The unification of several volume coil topologies results in a two-dimensional gridded equivalent lumped element circuit which compromises the birdcage resonator, its multiple endring derivative but also novel structures like the capacitive coupled ring resonator. The theory section analyzes a general two-dimensional circuit by noting that its current distribution can be decomposed into a longitudinal and an azimuthal dependency. This can be exploited to compare the current distribution with a transfer function of filter circuits along one direction. The resonances of the transfer function coincide with the resonance of the volume resonator and the simple analytical solution can be used as a design equation. The proposed framework is verified experimentally against a novel capacitive coupled ring structure which was derived from the general circuit formulation and is proven to exhibit a dominant homogeneous mode. In conclusion, a unified analytical framework is presented that allows determining the resonance frequency of any volume resonator that can be represented by a two dimensional meshed equivalent circuit.

Hydro-mechanically coupled finite-element analysis of the stability of a fractured-rock slope using the equivalent continuum approach: a case study of planned reservoir banks in Blaubeuren, Germany

NASA Astrophysics Data System (ADS)

Song, Jie; Dong, Mei; Koltuk, Serdar; Hu, Hui; Zhang, Luqing; Azzam, Rafig

2018-05-01

Construction works associated with the building of reservoirs in mountain areas can damage the stability of adjacent valley slopes. Seepage processes caused by the filling and drawdown operations of reservoirs also affect the stability of the reservoir banks over time. The presented study investigates the stability of a fractured-rock slope subjected to seepage forces in the lower basin of a planned pumped-storage hydropower (PSH) plant in Blaubeuren, Germany. The investigation uses a hydro-mechanically coupled finite-element analyses. For this purpose, an equivalent continuum model is developed by using a representative elementary volume (REV) approach. To determine the minimum required REV size, a large number of discrete fracture networks are generated using Monte Carlo simulations. These analyses give a REV size of 28 × 28 m, which is sufficient to represent the equivalent hydraulic and mechanical properties of the investigated fractured-rock mass. The hydro-mechanically coupled analyses performed using this REV size show that the reservoir operations in the examined PSH plant have negligible effect on the adjacent valley slope.

Prediction of properties and elemental composition of biomass pyrolysis oils by NMR and partial least squares analysis

USDA-ARS?s Scientific Manuscript database

Several partial least squares (PLS) models were created correlating various properties and chemical composition measurements with the 1H and 13C NMR spectra of 73 different of pyrolysis bio-oil samples from various biomass sources (crude and intermediate products), finished oils and small molecule s...

A Random Variable Related to the Inversion Vector of a Partial Random Permutation

ERIC Educational Resources Information Center

Laghate, Kavita; Deshpande, M. N.

2005-01-01

In this article, we define the inversion vector of a permutation of the integers 1, 2,..., n. We set up a particular kind of permutation, called a partial random permutation. The sum of the elements of the inversion vector of such a permutation is a random variable of interest.

Optimal design of composite hip implants using NASA technology

NASA Technical Reports Server (NTRS)

Blake, T. A.; Saravanos, D. A.; Davy, D. T.; Waters, S. A.; Hopkins, D. A.

1993-01-01

Using an adaptation of NASA software, we have investigated the use of numerical optimization techniques for the shape and material optimization of fiber composite hip implants. The original NASA inhouse codes, were originally developed for the optimization of aerospace structures. The adapted code, which was called OPORIM, couples numerical optimization algorithms with finite element analysis and composite laminate theory to perform design optimization using both shape and material design variables. The external and internal geometry of the implant and the surrounding bone is described with quintic spline curves. This geometric representation is then used to create an equivalent 2-D finite element model of the structure. Using laminate theory and the 3-D geometric information, equivalent stiffnesses are generated for each element of the 2-D finite element model, so that the 3-D stiffness of the structure can be approximated. The geometric information to construct the model of the femur was obtained from a CT scan. A variety of test cases were examined, incorporating several implant constructions and design variable sets. Typically the code was able to produce optimized shape and/or material parameters which substantially reduced stress concentrations in the bone adjacent of the implant. The results indicate that this technology can provide meaningful insight into the design of fiber composite hip implants.

Element free Galerkin formulation of composite beam with longitudinal slip

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

Ahmad, Dzulkarnain; Mokhtaram, Mokhtazul Haizad; Badli, Mohd Iqbal

2015-05-15

Behaviour between two materials in composite beam is assumed partially interact when longitudinal slip at its interfacial surfaces is considered. Commonly analysed by the mesh-based formulation, this study used meshless formulation known as Element Free Galerkin (EFG) method in the beam partial interaction analysis, numerically. As meshless formulation implies that the problem domain is discretised only by nodes, the EFG method is based on Moving Least Square (MLS) approach for shape functions formulation with its weak form is developed using variational method. The essential boundary conditions are enforced by Langrange multipliers. The proposed EFG formulation gives comparable results, after beenmore » verified by analytical solution, thus signify its application in partial interaction problems. Based on numerical test results, the Cubic Spline and Quartic Spline weight functions yield better accuracy for the EFG formulation, compares to other proposed weight functions.« less

42 CFR 3.212 - Nonidentification of patient safety work product.

Code of Federal Regulations, 2010 CFR

2010-10-01

... subdivisions smaller than a State, including street address, city, county, precinct, zip code and equivalent... three initial digits contains more than 20,000 people; (C) All elements of dates (except year) for dates...

Geometry of Conservation Laws for a Class of Parabolic Partial Differential Equations

NASA Astrophysics Data System (ADS)

Clelland, Jeanne Nielsen

1996-08-01

I consider the problem of computing the space of conservation laws for a second-order, parabolic partial differential equation for one function of three independent variables. The PDE is formulated as an exterior differential system {cal I} on a 12 -manifold M, and its conservation laws are identified with the vector space of closed 3-forms in the infinite prolongation of {cal I} modulo the so -called "trivial" conservation laws. I use the tools of exterior differential systems and Cartan's method of equivalence to study the structure of the space of conservation laws. My main result is:. Theorem. Any conservation law for a second-order, parabolic PDE for one function of three independent variables can be represented by a closed 3-form in the differential ideal {cal I} on the original 12-manifold M. I show that if a nontrivial conservation law exists, then {cal I} has a deprolongation to an equivalent system {cal J} on a 7-manifold N, and any conservation law for {cal I} can be expressed as a closed 3-form on N which lies in {cal J}. Furthermore, any such system in the real analytic category is locally equivalent to a system generated by a (parabolic) equation of the formA(u _{xx}u_{yy}-u_sp {xy}{2}) + B_1u_{xx }+2B_2u_{xy} +B_3u_ {yy}+C=0crwhere A, B_{i}, C are functions of x, y, t, u, u_{x}, u _{y}, u_{t}. I compute the space of conservation laws for several examples, and I begin the process of analyzing the general case using Cartan's method of equivalence. I show that the non-linearizable equation u_{t} = {1over2}e ^{-u}(u_{xx}+u_ {yy})has an infinite-dimensional space of conservation laws. This stands in contrast to the two-variable case, for which Bryant and Griffiths showed that any equation whose space of conservation laws has dimension 4 or more is locally equivalent to a linear equation, i.e., is linearizable.

Trace Elements Characteristic Based on ICP-AES and the Correlation of Flavonoids from Sparganii rhizoma.

PubMed

Wang, Xinsheng; Wu, Yanfang; Wu, Chengying; Wu, Qinan; Niu, Qingshan

2018-04-01

The aim of the present work was to investigate the trace elements and the correlation with flavonoids from Sparganii rhizoma. The ICP-AES and ultraviolet-visible spectroscopy were employed to analyze trace elements and flavonoids. The concentrations of trace elements and flavonoids were calculated using standard curve. The content of flavonoids was expressed as rutin equivalents. The cluster analysis was applied to evaluate geographical features of S. rhizoma from different geographical regions. The correlation analysis was used to obtain the relationship between the trace elements and flavonoids. The results indicated that the 15 trace elements were measured and the K, Ca, Mg, Na, Mn, Al, Cu, and Zn are rich in Sparganii rhizome. The different producing regions samples were classified into four groups. There was a weak relationship between trace elements and flavonoids.

Optimal moving grids for time-dependent partial differential equations

NASA Technical Reports Server (NTRS)

Wathen, A. J.

1989-01-01

Various adaptive moving grid techniques for the numerical solution of time-dependent partial differential equations were proposed. The precise criterion for grid motion varies, but most techniques will attempt to give grids on which the solution of the partial differential equation can be well represented. Moving grids are investigated on which the solutions of the linear heat conduction and viscous Burgers' equation in one space dimension are optimally approximated. Precisely, the results of numerical calculations of optimal moving grids for piecewise linear finite element approximation of partial differential equation solutions in the least squares norm.

Optimizing reconstruction of oncologic sternectomy defects based on surgical outcomes.

PubMed

Butterworth, James A; Garvey, Patrick B; Baumann, Donald P; Zhang, Hong; Rice, David C; Butler, Charles E

2013-08-01

The optimal strategy for oncologic sternectomy reconstruction has not been well characterized. We hypothesized that the major factors driving the reconstructive strategy for oncologic sternectomy include the need for skin replacement, extent of the bony sternectomy defect, and status of the internal mammary vessels. We reviewed consecutive oncologic sternectomy reconstructions performed at The University of Texas MD Anderson Cancer Center during a 10-year period. Regression models analyzed associations between patient, defect, and treatment factors and outcomes to identify patient and treatment selection criteria. We developed a generalized management algorithm based on these data. Forty-nine consecutive patients underwent oncologic sternectomy reconstruction (mean follow-up 18 ± 23 months). More sternectomies were partial (74%) rather than total/subtotal (26%). Most defects (n = 40 [82%]) required skeletal reconstruction. Pectoralis muscle flaps were most commonly used for sternectomies with intact overlying skin (64%) and infrequently used when a presternal skin defect was present (36%; p = 0.06). Free flaps were more often used for total/subtotal vs partial sternectomy defects (75% vs 25%, respectively; p = 0.02). Complication rates for total/subtotal sternectomy and partial sternectomy were equivalent (46% vs 44%, respectively; p = 0.92). Despite more extensive sternal resections, total/subtotal sternectomies resulted in equivalent postoperative complications when combined with the appropriate soft-tissue reconstruction. Good surgical and oncologic outcomes can be achieved with defect-characteristic-matched reconstructive strategies for these complex oncologic sternectomy resections. Copyright © 2013 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Survey of the status of finite element methods for partial differential equations

NASA Technical Reports Server (NTRS)

Temam, Roger

1986-01-01

The finite element methods (FEM) have proved to be a powerful technique for the solution of boundary value problems associated with partial differential equations of either elliptic, parabolic, or hyperbolic type. They also have a good potential for utilization on parallel computers particularly in relation to the concept of domain decomposition. This report is intended as an introduction to the FEM for the nonspecialist. It contains a survey which is totally nonexhaustive, and it also contains as an illustration, a report on some new results concerning two specific applications, namely a free boundary fluid-structure interaction problem and the Euler equations for inviscid flows.

Pharmacological versus sensory factors in the satiation of chocolate craving.

PubMed

Michener, W; Rozin, P

1994-09-01

This is the first experimental study directed at differentiating between physiological or sensory accounts of the satiation of nondrug cravings, using chocolate craving, the most common craving in North America. At the onset of craving, chocolate cravers consumed a chocolate bar, the caloric equivalent in "white chocolate" (containing none of the pharmacological components of chocolate), the pharmacological equivalent in cocoa capsules, placebo, and no treatment conditions had virtually no effect. White chocolate produced partial abatement, unchanged by the addition of all the pharmacological factors in cocoa. This result indicates no role for pharmacological effects in the satisfaction of chocolate craving. It also suggests a role for aroma independent of sweetness, texture, and calories.

Whatever Gave You That Idea? False Memories Following Equivalence Training: A Behavioral Account of the Misinformation Effect

PubMed Central

Challies, Danna M; Hunt, Maree; Garry, Maryanne; Harper, David N

2011-01-01

The misinformation effect is a term used in the cognitive psychological literature to describe both experimental and real-world instances in which misleading information is incorporated into an account of an historical event. In many real-world situations, it is not possible to identify a distinct source of misinformation, and it appears that the witness may have inferred a false memory by integrating information from a variety of sources. In a stimulus equivalence task, a small number of trained relations between some members of a class of arbitrary stimuli result in a large number of untrained, or emergent relations, between all members of the class. Misleading information was introduced into a simple memory task between a learning phase and a recognition test by means of a match-to-sample stimulus equivalence task that included both stimuli from the original learning task and novel stimuli. At the recognition test, participants given equivalence training were more likely to misidentify patterns than those who were not given such training. The misinformation effect was distinct from the effects of prior stimulus exposure, or partial stimulus control. In summary, stimulus equivalence processes may underlie some real-world manifestations of the misinformation effect. PMID:22084495

A search for neutrinoless double beta decay of tellurium-130

NASA Astrophysics Data System (ADS)

Bryant, Adam Douglas

This dissertation describes an experimental search for neutrinoless double beta (0nubetabeta) decay of 130Te. An observation of 0nubetabeta decay would establish that neutrinos are Majorana fermions and would constrain the neutrino mass scale. The data analyzed were collected by two bolometric experiments: CUORICINO and an R&D experiment for CUORE known as the Three Towers Test. Both experiments utilized arrays of TeO 2 crystals operated as bolometers at ˜10 mK in a dilution refrigerator. The bolometers measured the energy deposited by particle interactions in the crystals by recording the induced change in crystal temperature. Between the two experiments, there were 81 TeO2 bolometers used in the analysis, each of which was an independent detector of nuclear decays as well as a source of 130Te. The experiments were conducted underground at a depth of about 3300 meters water equivalent in Hall A of the Laboratori Nazionali del Gran Sasso in Assergi, Italy, in order to shield the detectors from cosmic rays. The data analyzed represent an exposure of 19.9 kg · y of 130Te (18.6 kg · y from CUORICINO and 1.3 kg · y from the Three Towers Test). In addition to the combined analysis of the two experiments, an analysis of CUORICINO data alone is presented in order to compare with an independent analysis being carried out by collaborators at the University of Milano-Bicocca. No signal due to 0nubetabeta decay is observed, and therefore a limit on the partial half-life for the decay is set. From a simultaneous fit to the 81 independent detectors, the rate of 0nubetabeta decay of 130Te is measured to be Gamma0nubetabeta( 130Te) = (-0.6+/-1.4 (stat.) +/- 0.4 (syst.)) x 10-25 y-1, which corresponds to a lower limit on the partial half-life for 0nubetabeta decay of 130Te of T0nbb1/2 (130Te) > 3.0x1024 y (90% C.L.). Converting the half-life limit to an upper limit on the effective Majorana neutrino mass, mbetabeta, using a set of recent nuclear matrix element calculations results in mbetabeta < 0.25--0.68 eV (90% C.L.), where the range reflects the spread of calculated nuclear matrix element values. These results disagree by at least 1.2sigma, depending on the nuclear matrix element calculation, with a claim of observation of 0nubetabeta decay of 76Ge, assuming that the dominant mechanism driving 0nubetabeta decay is the exchange of light Majorana neutrinos.

Digital Equivalent Data System for XRF Labeling of Objects

NASA Technical Reports Server (NTRS)

Schramm, Harry F.; Kaiser, Bruce

2005-01-01

A digital equivalent data system (DEDS) is a system for identifying objects by means of the x-ray fluorescence (XRF) spectra of labeling elements that are encased in or deposited on the objects. As such, a DEDS is a revolutionary new major subsystem of an XRF system. A DEDS embodies the means for converting the spectral data output of an XRF scanner to an ASCII alphanumeric or barcode label that can be used to identify (or verify the assumed or apparent identity of) an XRF-scanned object. A typical XRF spectrum of interest contains peaks at photon energies associated with specific elements on the Periodic Table (see figure). The height of each spectral peak above the local background spectral intensity is proportional to the relative abundance of the corresponding element. Alphanumeric values are assigned to the relative abundances of the elements. Hence, if an object contained labeling elements in suitably chosen proportions, an alphanumeric representation of the object could be extracted from its XRF spectrum. The mixture of labeling elements and for reading the XRF spectrum would be compatible with one of the labeling conventions now used for bar codes and binary matrix patterns (essentially, two-dimensional bar codes that resemble checkerboards). A further benefit of such compatibility is that it would enable the conversion of the XRF spectral output to a bar or matrix-coded label, if needed. In short, a process previously used only for material composition analysis has been reapplied to the world of identification. This new level of verification is now being used for "authentication."

Origin of the Mackenzie large igneous province and sourcing of flood basalts from layered intrusions

NASA Astrophysics Data System (ADS)

Day, J. M.; Pearson, D.

2013-12-01

The 1.27 Ga Coppermine continental flood basalt (CFB) in northern Canada represents the extrusive manifestation of the Mackenzie large igneous province (LIP) that includes the Mackenzie dyke swarm and the Muskox layered intrusion. New Re-Os isotope and highly siderophile element (HSE: Re, Pd, Pt, Ru, Ir, Os) abundance data are reported together with whole-rock major- and trace-element abundances and Nd isotopes to examine the behaviour of the HSE during magmatic differentiation and to place constraints on the extent of crustal interaction with mantle-derived melts. Mineral-chemical data are also reported for an unusual andesite glass flow (4.9 wt.% MgO) found in proximity to newly recognised picrites (>20 wt.% MgO) in the lowermost stratigraphy of the Coppermine CFB. Compositions of mineral phases in the andesite are similar to equivalent phases found in Muskox Intrusion chromitites and the melt composition is identical to Muskox chromite melt inclusions. Elevated HSE contents (e.g., 3.8 ppb Os) and the mantle-like initial Os isotope composition of this andesitic glass contrast strongly with oxygen isotope and lithophile element evidence for extensive crustal contamination. These signatures implicate an origin for the glass as a magma mingling product formed within the Muskox Intrusion during chromitite genesis. The combination of crust and mantle signatures define roles for both these reservoirs in chromitite genesis, but the HSE appear to be dominantly mantle-sourced. Combined with Nd isotope data that places the feeder for lower Coppermine CFB picrites and basalts within the Muskox Intrusion, this provides the strongest evidence yet for direct processing of some CFB within upper-crustal magma chambers. Modeling of absolute and relative HSE abundances in CFB reveal that HSE concentrations decrease with increasing fractionation for melts with <8×1 wt.% MgO in the Coppermine CFB, with picrites (>13.5wt.% MgO) from CFB having higher Os abundances than ocean island basalt (OIB) equivalents. The differences between CFB and OIB picrite absolute Os abundances may result from higher degrees of partial melting to form CFB but may also reflect incorporation of trace sulphide in CFB picrites from magmas that reached S-saturation in shallow-level magma chambers. Significant inter-element fractionation between (Re+Pt+Pd)/(Os+Ir+Ru) are generated during magmatic differentiation in response to strongly contrasting partitioning of these two groups of elements into sulphides and/or HSE-rich alloys. Furthermore, fractional crystallization has a greater role on absolute and relative HSE abundances than crustal contamination under conditions of CFB petrogenesis due to the dilution effect of continental crust. The Coppermine CFB define a Re-Os isochron with an age of 1263 +16/-20 Ma and initial gamma Os = +2.2×0.8. Combined data for the basaltic and intrusive portions of the Mackenzie LIP indicate a mantle source broadly within the range of the primitive upper mantle. The majority of Archaean komatiites and Phanerozoic CFB also require mantle sources with primitive upper mantle to chondritic Re/Os evolution, with exceptions typically being from analyses of highly-fractionated MgO-poor basalts.

Domain atrophy creates rare cases of functional partial protein domains.

PubMed

Prakash, Ananth; Bateman, Alex

2015-04-30

Protein domains display a range of structural diversity, with numerous additions and deletions of secondary structural elements between related domains. We have observed a small number of cases of surprising large-scale deletions of core elements of structural domains. We propose a new concept called domain atrophy, where protein domains lose a significant number of core structural elements. Here, we implement a new pipeline to systematically identify new cases of domain atrophy across all known protein sequences. The output of this pipeline was carefully checked by hand, which filtered out partial domain instances that were unlikely to represent true domain atrophy due to misannotations or un-annotated sequence fragments. We identify 75 cases of domain atrophy, of which eight cases are found in a three-dimensional protein structure and 67 cases have been inferred based on mapping to a known homologous structure. Domains with structural variations include ancient folds such as the TIM-barrel and Rossmann folds. Most of these domains are observed to show structural loss that does not affect their functional sites. Our analysis has significantly increased the known cases of domain atrophy. We discuss specific instances of domain atrophy and see that there has often been a compensatory mechanism that helps to maintain the stability of the partial domain. Our study indicates that although domain atrophy is an extremely rare phenomenon, protein domains under certain circumstances can tolerate extreme mutations giving rise to partial, but functional, domains.

Distortions in 2p4d Partial Fluorescence yield for 4d elements

NASA Astrophysics Data System (ADS)

Price, Alexander; de Groot, Frank; Datta, Trinanjan

2014-03-01

X-ray absorption spectroscopy (XAS) is a standard tool to determine the electronic structure of molecules and materials. CTM4XAS and CTM4RIXS are semi-empirical programs to analyze transition metal L - and M - edge transitions by evaluating the effects of crystal field and charge transfer parameters on the atomic multiplets. We compute and compare the XAS and the fluorescence yield (FY) XAS, of the 3d and 4d transition metal ions. In the case of 2p edges of 3d elements Auger decay dominates and sets the time scale. The 2p3d X -ray emission spectra (XES) accounts for approximately 80% of the radiative decay. The 2p3d partial FY is distorted and because it dominates the FY, the total FY is also distorted. For the 4d elements the 2p4d XES decay is approximately 10% of 2p3d XES decay, implying that (the energy-constant) core-core XES and Auger channels dominate the decay. The computed 2p4d partial FY -XAS spectra are different from the 2p XAS. Although 2p4d partial FY is distorted, the total FY is not because it is dominated by 2p3d XES. We also find that the 2p3s and 2p4s XES channels contribute less than 1% and can be neglected. Cottrell Research Corporation.

Grades, Student Satisfaction and Retention in Online and Face-to-Face Introductory Psychology Units: A Test of Equivalency Theory.

PubMed

Garratt-Reed, David; Roberts, Lynne D; Heritage, Brody

2016-01-01

There has been a recent rapid growth in the number of psychology courses offered online through institutions of higher education. The American Psychological Association has highlighted the importance of ensuring the effectiveness of online psychology courses (Halonen et al., 2013). Despite this, there have been inconsistent findings regarding student grades, satisfaction, and retention in online psychology units. Equivalency Theory (Simonson, 1999; Simonson et al., 1999) posits that online and classroom-based learners will attain equivalent learning outcomes when equivalent learning experiences are provided. We present a study of an online introductory psychology unit designed to provide equivalent learning experiences to the pre-existing face-to-face version of the unit. Using quasi-experimental methods, academic performance, student feedback, and retention data from 866 Australian undergraduate psychology students were examined to assess whether the online unit developed to provide equivalent learning experiences produced comparable outcomes to the 'traditional' unit delivered face-to-face. Student grades did not significantly differ between modes of delivery, except for a group-work based assessment where online students performed more poorly. Student satisfaction was generally high in both modes of the unit, with group-work the key source of dissatisfaction in the online unit. The results provide partial support for Equivalency Theory. The group-work based assessment did not provide an equivalent learning experience for students in the online unit highlighting the need for further research to determine effective methods of engaging students in online group activities. Consistent with previous research, retention rates were significantly lower in the online unit, indicating the need to develop effective strategies to increase online retention rates. While this study demonstrates successes in presenting students with an equivalent learning experience, we recommend that future research investigate means of successfully facilitating collaborative group-work assessment, and to explore contributing factors to actual student retention in online units beyond that of non-equivalent learning experiences.

Equivalent theories redefine Hamiltonian observables to exhibit change in general relativity

NASA Astrophysics Data System (ADS)

Pitts, J. Brian

2017-03-01

Change and local spatial variation are missing in canonical General Relativity’s observables as usually defined, an aspect of the problem of time. Definitions can be tested using equivalent formulations of a theory, non-gauge and gauge, because they must have equivalent observables and everything is observable in the non-gauge formulation. Taking an observable from the non-gauge formulation and finding the equivalent in the gauge formulation, one requires that the equivalent be an observable, thus constraining definitions. For massive photons, the de Broglie-Proca non-gauge formulation observable {{A}μ} is equivalent to the Stueckelberg-Utiyama gauge formulation quantity {{A}μ}+{{\\partial}μ}φ, which must therefore be an observable. To achieve that result, observables must have 0 Poisson bracket not with each first-class constraint, but with the Rosenfeld-Anderson-Bergmann-Castellani gauge generator G, a tuned sum of first-class constraints, in accord with the Pons-Salisbury-Sundermeyer definition of observables. The definition for external gauge symmetries can be tested using massive gravity, where one can install gauge freedom by parametrization with clock fields X A . The non-gauge observable {{g}μ ν} has the gauge equivalent {{X}A}{{,}μ}{{g}μ ν}{{X}B}{{,}ν}. The Poisson bracket of {{X}A}{{,}μ}{{g}μ ν}{{X}B}{{,}ν} with G turns out to be not 0 but a Lie derivative. This non-zero Poisson bracket refines and systematizes Kuchař’s proposal to relax the 0 Poisson bracket condition with the Hamiltonian constraint. Thus observables need covariance, not invariance, in relation to external gauge symmetries. The Lagrangian and Hamiltonian for massive gravity are those of General Relativity  +   Λ   +  4 scalars, so the same definition of observables applies to General Relativity. Local fields such as {{g}μ ν} are observables. Thus observables change. Requiring equivalent observables for equivalent theories also recovers Hamiltonian-Lagrangian equivalence.

Grades, Student Satisfaction and Retention in Online and Face-to-Face Introductory Psychology Units: A Test of Equivalency Theory

PubMed Central

Garratt-Reed, David; Roberts, Lynne D.; Heritage, Brody

2016-01-01

There has been a recent rapid growth in the number of psychology courses offered online through institutions of higher education. The American Psychological Association has highlighted the importance of ensuring the effectiveness of online psychology courses (Halonen et al., 2013). Despite this, there have been inconsistent findings regarding student grades, satisfaction, and retention in online psychology units. Equivalency Theory (Simonson, 1999; Simonson et al., 1999) posits that online and classroom-based learners will attain equivalent learning outcomes when equivalent learning experiences are provided. We present a study of an online introductory psychology unit designed to provide equivalent learning experiences to the pre-existing face-to-face version of the unit. Using quasi-experimental methods, academic performance, student feedback, and retention data from 866 Australian undergraduate psychology students were examined to assess whether the online unit developed to provide equivalent learning experiences produced comparable outcomes to the ‘traditional’ unit delivered face-to-face. Student grades did not significantly differ between modes of delivery, except for a group-work based assessment where online students performed more poorly. Student satisfaction was generally high in both modes of the unit, with group-work the key source of dissatisfaction in the online unit. The results provide partial support for Equivalency Theory. The group-work based assessment did not provide an equivalent learning experience for students in the online unit highlighting the need for further research to determine effective methods of engaging students in online group activities. Consistent with previous research, retention rates were significantly lower in the online unit, indicating the need to develop effective strategies to increase online retention rates. While this study demonstrates successes in presenting students with an equivalent learning experience, we recommend that future research investigate means of successfully facilitating collaborative group-work assessment, and to explore contributing factors to actual student retention in online units beyond that of non-equivalent learning experiences. PMID:27242587

21 CFR 610.13 - Purity.

Code of Federal Regulations, 2012 CFR

2012-04-01

... substances is not required for the following products: Products containing formed blood elements... antigens; toxoids; toxins; allergenic extracts; venoms; diagnostic substances and trivalent organic... human blood; (ii) for Streptokinase, the test dose shall be at least equivalent proportionately, on a...

21 CFR 610.13 - Purity.

Code of Federal Regulations, 2014 CFR

2014-04-01

... substances is not required for the following products: Products containing formed blood elements... antigens; toxoids; toxins; allergenic extracts; venoms; diagnostic substances and trivalent organic... human blood; (ii) for Streptokinase, the test dose shall be at least equivalent proportionately, on a...

21 CFR 610.13 - Purity.

Code of Federal Regulations, 2010 CFR

2010-04-01

... substances is not required for the following products: Products containing formed blood elements... antigens; toxoids; toxins; allergenic extracts; venoms; diagnostic substances and trivalent organic... human blood; (ii) for Streptokinase, the test dose shall be at least equivalent proportionately, on a...

21 CFR 610.13 - Purity.

Code of Federal Regulations, 2013 CFR

2013-04-01

... substances is not required for the following products: Products containing formed blood elements... antigens; toxoids; toxins; allergenic extracts; venoms; diagnostic substances and trivalent organic... human blood; (ii) for Streptokinase, the test dose shall be at least equivalent proportionately, on a...

21 CFR 610.13 - Purity.

Code of Federal Regulations, 2011 CFR

2011-04-01

... substances is not required for the following products: Products containing formed blood elements... antigens; toxoids; toxins; allergenic extracts; venoms; diagnostic substances and trivalent organic... human blood; (ii) for Streptokinase, the test dose shall be at least equivalent proportionately, on a...

Elements of orbit-determination theory - Textbook

NASA Technical Reports Server (NTRS)

Solloway, C. B.

1971-01-01

Text applies to solution of various optimization problems. Concepts are logically introduced and refinements and complexities for computerized numerical solutions are avoided. Specific topics and essential equivalence of several different approaches to various aspects of the problem are given.

Mechanistic equivalent circuit modelling of a commercial polymer electrolyte membrane fuel cell

NASA Astrophysics Data System (ADS)

Giner-Sanz, J. J.; Ortega, E. M.; Pérez-Herranz, V.

2018-03-01

Electrochemical impedance spectroscopy (EIS) has been widely used in the fuel cell field since it allows deconvolving the different physic-chemical processes that affect the fuel cell performance. Typically, EIS spectra are modelled using electric equivalent circuits. In this work, EIS spectra of an individual cell of a commercial PEM fuel cell stack were obtained experimentally. The goal was to obtain a mechanistic electric equivalent circuit in order to model the experimental EIS spectra. A mechanistic electric equivalent circuit is a semiempirical modelling technique which is based on obtaining an equivalent circuit that does not only correctly fit the experimental spectra, but which elements have a mechanistic physical meaning. In order to obtain the aforementioned electric equivalent circuit, 12 different models with defined physical meanings were proposed. These equivalent circuits were fitted to the obtained EIS spectra. A 2 step selection process was performed. In the first step, a group of 4 circuits were preselected out of the initial list of 12, based on general fitting indicators as the determination coefficient and the fitted parameter uncertainty. In the second step, one of the 4 preselected circuits was selected on account of the consistency of the fitted parameter values with the physical meaning of each parameter.

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

Hasan, Iftekhar; Husain, Tausif; Sozer, Yilmaz

This paper proposes an analytical machine design tool using magnetic equivalent circuit (MEC)-based particle swarm optimization (PSO) for a double-sided, flux-concentrating transverse flux machine (TFM). The magnetic equivalent circuit method is applied to analytically establish the relationship between the design objective and the input variables of prospective TFM designs. This is computationally less intensive and more time efficient than finite element solvers. A PSO algorithm is then used to design a machine with the highest torque density within the specified power range along with some geometric design constraints. The stator pole length, magnet length, and rotor thickness are the variablesmore » that define the optimization search space. Finite element analysis (FEA) was carried out to verify the performance of the MEC-PSO optimized machine. The proposed analytical design tool helps save computation time by at least 50% when compared to commercial FEA-based optimization programs, with results found to be in agreement with less than 5% error.« less

Dielectric monitoring of carbon nanotube network formation in curing thermosetting nanocomposites

NASA Astrophysics Data System (ADS)

Battisti, A.; Skordos, A. A.; Partridge, I. K.

2009-08-01

This paper focuses on monitoring of carbon nanotube (CNT) network development during the cure of unsaturated polyester nanocomposites by means of electrical impedance spectroscopy. A phenomenological model of the dielectric response is developed using equivalent circuit analysis. The model comprises two parallel RC elements connected in series, each of them giving rise to a semicircular arc in impedance complex plane plots. An established inverse modelling methodology is utilized for the estimation of the parameters of the corresponding equivalent circuit. This allows a quantification of the evolution of two separate processes corresponding to the two parallel RC elements. The high frequency process, which is attributed to CNT aggregates, shows a monotonic decrease in characteristic time during the cure. In contrast, the low frequency process, which corresponds to inter-aggregate phenomena, shows a more complex behaviour explained by the interplay between conductive network development and the cross-linking of the polymer.

Non-detonable and non-explosive explosive simulators

DOEpatents

Simpson, R.L.; Pruneda, C.O.

1997-07-15

A simulator which is chemically equivalent to an explosive, but is not detonable or explodable is disclosed. The simulator is a combination of an explosive material with an inert material, either in a matrix or as a coating, where the explosive has a high surface ratio but small volume ratio. The simulator has particular use in the training of explosives detecting dogs, calibrating analytical instruments which are sensitive to either vapor or elemental composition, or other applications where the hazards associated with explosives is undesirable but where chemical and/or elemental equivalence is required. The explosive simulants may be fabricated by different techniques. A first method involves the use of standard slurry coatings to produce a material with a very high binder to explosive ratio without masking the explosive vapor, and a second method involves coating inert substrates with thin layers of explosive. 11 figs.

Returning to the bedside: using the history and physical examination to identify rotator cuff tears.

PubMed

Litaker, D; Pioro, M; El Bilbeisi, H; Brems, J

2000-12-01

To determine the value of elements of the bedside history and physical examination in predicting arthrography results in older patients with suspected rotator cuff tear (RCT). Retrospective chart review Orthopedic practice limited to disorders of the shoulder 448 consecutive patients with suspected RCT referred for arthrography over a 4-year period Presence of partial or complete RCT on arthrogram 301 patients (67.2%) had evidence of complete or partial RCT. Clinical findings in the univariate analysis most closely associated with rotator cuff tear included infra- and supraspinatus atrophy (P < .001), weakness with either elevation (P < .001) or external rotation (P < .001), arc of pain (P = .004), and impingement sign (P = .01). Stepwise logistic regression based on a derivation dataset (n = 191) showed that weakness with external rotation (Adjusted Odds Ratio (AOR) 6.96 (3.09, 13.03)), age > or = 65 (AOR 4.05(2.47, 16.07)), and night pain (AOR 2.61 (1.004, 7.39)) best predicted the presence of RCT. A five-point scoring system developed from this model was applied in the remaining patient sample (n = 216) to test validity. No significant differences in performance were noted using ROC curve comparison. Using likelihood ratios, a clinical score = 4 was superior in predicting RCT to the diagnostic prediction of an expert clinician. This score had specificity equivalent to magnetic resonance imaging or ultrasonography in diagnosis of RCT. The presence of three simple features in the history and physical examination of the shoulder can identify RCT efficiently. This approach offers a valuable strategy to diagnosis at the bedside without compromising sensitivity or specificity.

Analysis of load distribution in tooth-implant supported fixed partial dentures by the use of resilient abutment.

PubMed

Glisić, Mirko; Stamenković, Dragoslav; Grbović, Aleksandar; Todorović, Aleksandar; Marković, Aleksa; Trifković, Branka

2016-01-01

Differences between the tooth and implant response to load can lead to many biological and technical implications in the conditions of occlusal forces. The objective of this study was to analyze load distribution in tooth/implant-supported fixed partial dentures with the use of resilient TSA (Titan Shock Absorber, BoneCare GmbH, Augsburg, Germany) abutment and conventional non-resilient abutment using finite element method. This study presents two basic 3D models. For one model a standard non-resilient abutment is used, and on the implant of the second model a resilient TSA abutment is applied. The virtual model contains drawn contours of tooth, mucous membranes, implant, cortical bones and spongiosa, abutment and suprastructure. The experiment used 500 N of vertical force, applied in three different cases of axial load. Calculations of von Mises equivalent stresses of the tooth root and periodontium, implants and peri-implant tissue were made. For the model to which a non-resilient abutment is applied, maximum stress values in all three cases are observed in the cortical part of the bone (maximum stress value of 49.7 MPa). Measurements of stress and deformation in the bone tissue in the model with application of the resilientTSA abutment demonstrated similar distribution; however, these values are many times lower than in the model with non-resilient TSA abutment (maximum stress value of 28.9 MPa). Application of the resilient TSA abutment results in more equal distribution of stress and deformations in the bone tissue under vertical forces. These values are many times lower than in the model with the non-resilient abutment.

SCCmecFinder, a Web-Based Tool for Typing of Staphylococcal Cassette Chromosome mec in Staphylococcus aureus Using Whole-Genome Sequence Data.

PubMed

Kaya, Hülya; Hasman, Henrik; Larsen, Jesper; Stegger, Marc; Johannesen, Thor Bech; Allesøe, Rosa Lundbye; Lemvigh, Camilla Koldbæk; Aarestrup, Frank Møller; Lund, Ole; Larsen, Anders Rhod

2018-01-01

Typing of methicillin-resistant Staphylococcus aureus (MRSA) is important in infection control and surveillance. The current nomenclature of MRSA includes the genetic background of the S. aureus strain determined by multilocus sequence typing (MLST) or equivalent methods like spa typing and typing of the mobile genetic element staphylococcal cassette chromosome mec (SCC mec ), which carries the mecA or mecC gene. Whereas MLST and spa typing are relatively simple, typing of SCC mec is less trivial because of its heterogeneity. Whole-genome sequencing (WGS) provides the essential data for typing of the genetic background and SCC mec , but so far, no bioinformatic tools for SCC mec typing have been available. Here, we report the development and evaluation of SCC mec Finder for characterization of the SCC mec element from S. aureus WGS data. SCC mec Finder is able to identify all SCC mec element types, designated I to XIII, with subtyping of SCC mec types IV (2B) and V (5C2). SCC mec elements are characterized by two different gene prediction approaches to achieve correct annotation, a Basic Local Alignment Search Tool (BLAST)-based approach and a k -mer-based approach. Evaluation of SCC mec Finder by using a diverse collection of clinical isolates ( n = 93) showed a high typeability level of 96.7%, which increased to 98.9% upon modification of the default settings. In conclusion, SCC mec Finder can be an alternative to more laborious SCC mec typing methods and is freely available at https://cge.cbs.dtu.dk/services/SCCmecFinder. IMPORTANCE SCC mec in MRSA is acknowledged to be of importance not only because it contains the mecA or mecC gene but also for staphylococcal adaptation to different environments, e.g., in hospitals, the community, and livestock. Typing of SCC mec by PCR techniques has, because of its heterogeneity, been challenging, and whole-genome sequencing has only partially solved this since no good bioinformatic tools have been available. In this article, we describe the development of a new bioinformatic tool, SCC mec Finder, that includes most of the needs for infection control professionals and researchers regarding the interpretation of SCC mec elements. The software detects all of the SCC mec elements accepted by the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements, and users will be prompted if diverging and potential new elements are uploaded. Furthermore, SCC mec Finder will be curated and updated as new elements are found and it is easy to use and freely accessible.

Finding Mount Everest and handling voids.

PubMed

Storch, Tobias

2011-01-01

Evolutionary algorithms (EAs) are randomized search heuristics that solve problems successfully in many cases. Their behavior is often described in terms of strategies to find a high location on Earth's surface. Unfortunately, many digital elevation models describing it contain void elements. These are elements not assigned an elevation. Therefore, we design and analyze simple EAs with different strategies to handle such partially defined functions. They are experimentally investigated on a dataset describing the elevation of Earth's surface. The largest value found by an EA within a certain runtime is measured, and the median over a few runs is computed and compared for the different EAs. For the dataset, the distribution of void elements seems to be neither random nor adversarial. They are so-called semirandomly distributed. To deepen our understanding of the behavior of the different EAs, they are theoretically considered on well-known pseudo-Boolean functions transferred to partially defined ones. These modifications are also performed in a semirandom way. The typical runtime until an optimum is found by an EA is analyzed, namely bounded from above and below, and compared for the different EAs. We figure out that for the random model it is a good strategy to assume that a void element has a worse function value than all previous elements. Whereas for the adversary model it is a good strategy to assume that a void element has the best function value of all previous elements.

Chemical element accumulation in tree bark grown in volcanic soils of Cape Verde-a first biomonitoring of Fogo Island.

PubMed

Marques, Rosa; Prudêncio, Maria Isabel; Freitas, Maria do Carmo; Dias, Maria Isabel; Rocha, Fernando

2017-05-01

Barks from Prosopis juliflora (acacia) were collected in 12 sites of different geological contexts over the volcanic Fogo Island (Cape Verde). Elemental contents of Ba, Br, Co, Cr, Fe, K, Na, Zn and some rare earth elements (REE)-La, Ce, Sm, Eu, Tb, Yb, and Lu, were obtained for biological samples and topsoils by using k 0 -standardized and comparative method of instrumental neutron activation analysis (INAA), aiming the evaluation of chemical elements uptake by acacia bark. This first biomonitoring study of Fogo Island showed that, in general, significant accumulations of trace elements present in high amounts in these soils occur. This can be partially explained by the semi-arid climate with a consequent bioavailability of chemical elements when rain drops fall in this non-polluted environment. REE enrichment factors (EFs) increase with the decrease of ionic radius. Heavy REE (HREE) are significantly enriched in bark, which agrees with their release after the primary minerals breakdown and the formation of more soluble compounds than the other REE, and uptake by plants. Among the potential harmful chemical elements, Cr appears to be partially retained in nanoparticles of iron oxides. The high EFs found in tree barks of Fogo Island are certainly of geogenic origin rather than anthropogenic input since industry and the use of fertilizers is scarce.

Determination of Important Nuclear Fragmentation Processes for Human Space Radiation Protection

NASA Technical Reports Server (NTRS)

Lin, Zi-Wei

2007-01-01

We present a semi-analytical method to determine which partial cross sections of nuclear fragmentations most affect the shielded dose equivalent due to exposure to galactic cosmic rays. The cross sections thus determined will require more theoretical and/or experimental studies in order for us to better predict, reduce and mitigate the radiation exposure in human space explorations.

Investigation of flame structure and burning intensity of partially premixed methane enrichment of syngas using OH-PLIF and kinetic simulation

NASA Astrophysics Data System (ADS)

Pu, Ge; Huang, Beibei; Zhang, Xun; Du, Jiantai; Zhu, Tuanhui; Chen, Bei

2018-05-01

Various experiments were conducted to study the combustion characteristics of partially premixed methane enrichment of syngas by using the OH-PLIF technique. Experiments were conducted on a co-flow burner, and the methane concentration (XCH4 = CH4/(H2+CO+CH4)) was varied from 0 to 20%, the overall equivalence ratio was varied from 0.4 to 1.2 and the inner equivalence ratio was varied from 1.5 to 3.5. Kinetic simulation was conducted by using OPPDIF module of CHEMKIN-Pro software. Results show that an increase in XCH4 and ϕoverall weakens the OH signal intensity. Adding methane into the fuel greatly increases the height of the inner flame front, and the increase of methane concentration has a negative effect on flame propagation speed. Meanwhile, simulation results remain consistent with the experiments. The main OH radical production reaction changes from R46: H+HO2 = 2OH to R38: H+O2 = O+OH when methane concentration contained in the fuel mixture increases. Sensitivity analysis also indicates that reaction which plays a dominant effect on temperature changes with the increase of methane concentration.

Sequential Auctions with Partially Substitutable Goods

NASA Astrophysics Data System (ADS)

Vetsikas, Ioannis A.; Jennings, Nicholas R.

In this paper, we examine a setting in which a number of partially substitutable goods are sold in sequential single unit auctions. Each bidder needs to buy exactly one of these goods. In previous work, this setting has been simplified by assuming that bidders do not know their valuations for all items a priori, but rather are informed of their true valuation for each item right before the corresponding auction takes place. This assumption simplifies the strategies of bidders, as the expected revenue from future auctions is the same for all bidders due to the complete lack of private information. In our analysis we don't make this assumption. This complicates the computation of the equilibrium strategies significantly. We examine this setting both for first and second-price auction variants, initially when the closing prices are not announced, for which we prove that sequential first and second-price auctions are revenue equivalent. Then we assume that the prices are announced; because of the asymmetry in the announced prices between the two auction variants, revenue equivalence does not hold in this case. We finish the paper, by giving some initial results about the case when free disposal is allowed, and therefore a bidder can purchase more than one item.

Semidiscrete Galerkin modelling of compressible viscous flow past a circular cone at incidence. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Meade, Andrew James, Jr.

1989-01-01

A numerical study of the laminar and compressible boundary layer, about a circular cone in a supersonic free stream, is presented. It is thought that if accurate and efficient numerical schemes can be produced to solve the boundary layer equations, they can be joined to numerical codes that solve the inviscid outer flow. The combination of these numerical codes is competitive with the accurate, but computationally expensive, Navier-Stokes schemes. The primary goal is to develop a finite element method for the calculation of 3-D compressible laminar boundary layer about a yawed cone. The proposed method can, in principle, be extended to apply to the 3-D boundary layer of pointed bodies of arbitrary cross section. The 3-D boundary layer equations governing supersonic free stream flow about a cone are examined. The 3-D partial differential equations are reduced to 2-D integral equations by applying the Howarth, Mangler, Crocco transformations, a linear relation between viscosity, and a Blasius-type of similarity variable. This is equivalent to a Dorodnitsyn-type formulation. The reduced equations are independent of density and curvature effects, and resemble the weak form of the 2-D incompressible boundary layer equations in Cartesian coordinates. In addition the coordinate normal to the wall has been stretched, which reduces the gradients across the layer and provides high resolution near the surface. Utilizing the parabolic nature of the boundary layer equations, a finite element method is applied to the Dorodnitsyn formulation. The formulation is presented in a Petrov-Galerkin finite element form and discretized across the layer using linear interpolation functions. The finite element discretization yields a system of ordinary differential equations in the circumferential direction. The circumferential derivatives are solved by an implicit and noniterative finite difference marching scheme. Solutions are presented for a 15 deg half angle cone at angles of attack of 5 and 10 deg. The numerical solutions assume a laminar boundary layer with free stream Mach number of 7. Results include circumferential distribution of skin friction and surface heat transfer, and cross flow velocity distributions across the layer.

Mechanical characterization and structural analysis of recycled fiber-reinforced-polymer resin-transfer-molded beams

NASA Astrophysics Data System (ADS)

Tan, Eugene Wie Loon

1999-09-01

The present investigation was focussed on the mechanical characterization and structural analysis of resin-transfer-molded beams containing recycled fiber-reinforced polymers. The beams were structurally reinforced with continuous unidirectional glass fibers. The reinforcing filler materials consisted entirely of recycled fiber-reinforced polymer wastes (trim and overspray). The principal resin was a 100-percent dicyclo-pentadiene unsaturated polyester specially formulated with very low viscosity for resin transfer molding. Variations of the resin transfer molding technique were employed to produce specimens for material characterization. The basic materials that constituted the structural beams, continuous-glass-fiber-reinforced, recycled-trim-filled and recycled-overspray-filled unsaturated polyesters, were fully characterized in axial and transverse compression and tension, and inplane and interlaminar shear, to ascertain their strengths, ultimate strains, elastic moduli and Poisson's ratios. Experimentally determined mechanical properties of the recycled-trim-filled and recycled-overspray-filled materials from the present investigation were superior to those of unsaturated polyester polymer concretes and Portland cement concretes. Mechanical testing and finite element analyses of flexure (1 x 1 x 20 in) and beam (2 x 4 x 40 in) specimens were conducted. These structurally-reinforced specimens were tested and analyzed in four-point, third-point flexure to determine their ultimate loads, maximum fiber stresses and mid-span deflections. The experimentally determined load capacities of these specimens were compared to those of equivalent steel-reinforced Portland cement concrete beams computed using reinforced concrete theory. Mechanics of materials beam theory was utilized to predict the ultimate loads and mid-span deflections of the flexure and beam specimens. However, these predictions proved to be severely inadequate. Finite element (fracture propagation) analyses of the flexure and beam specimens were also performed. These progressive failure analyses more closely approximated flexural behavior under actual testing conditions by reducing the elastic moduli of elements that were considered to have partially or totally failed. Individual element failures were predicted using the maximum stress, Tsai-Hill and Tsai-Wu failure criteria. Excellent predictions of flexural behavior were attributed to the progressive failure analyses combined with an appropriate failure criterion, and the reliable input material properties that were generated.

Comparison of baseline removal methods for laser-induced breakdown spectroscopy of geological samples

NASA Astrophysics Data System (ADS)

Dyar, M. Darby; Giguere, Stephen; Carey, CJ; Boucher, Thomas

2016-12-01

This project examines the causes, effects, and optimization of continuum removal in laser-induced breakdown spectroscopy (LIBS) to produce the best possible prediction accuracy of elemental composition in geological samples. We compare prediction accuracy resulting from several different techniques for baseline removal, including asymmetric least squares (ALS), adaptive iteratively reweighted penalized least squares (Air-PLS), fully automatic baseline correction (FABC), continuous wavelet transformation, median filtering, polynomial fitting, the iterative thresholding Dietrich method, convex hull/rubber band techniques, and a newly-developed technique for Custom baseline removal (BLR). We assess the predictive performance of these methods using partial least-squares analysis for 13 elements of geological interest, expressed as the weight percentages of SiO2, Al2O3, TiO2, FeO, MgO, CaO, Na2O, K2O, and the parts per million concentrations of Ni, Cr, Zn, Mn, and Co. We find that previously published methods for baseline subtraction generally produce equivalent prediction accuracies for major elements. When those pre-existing methods are used, automated optimization of their adjustable parameters is always necessary to wring the best predictive accuracy out of a data set; ideally, it should be done for each individual variable. The new technique of Custom BLR produces significant improvements in prediction accuracy over existing methods across varying geological data sets, instruments, and varying analytical conditions. These results also demonstrate the dual objectives of the continuum removal problem: removing a smooth underlying signal to fit individual peaks (univariate analysis) versus using feature selection to select only those channels that contribute to best prediction accuracy for multivariate analyses. Overall, the current practice of using generalized, one-method-fits-all-spectra baseline removal results in poorer predictive performance for all methods. The extra steps needed to optimize baseline removal for each predicted variable and empower multivariate techniques with the best possible input data for optimal prediction accuracy are shown to be well worth the slight increase in necessary computations and complexity.

Finite element modeling and analysis of tires

NASA Technical Reports Server (NTRS)

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

1983-01-01

Predicting the response of tires under various loading conditions using finite element technology is addressed. Some of the recent advances in finite element technology which have high potential for application to tire modeling problems are reviewed. The analysis and modeling needs for tires are identified. Reduction methods for large-scale nonlinear analysis, with particular emphasis on treatment of combined loads, displacement-dependent and nonconservative loadings; development of simple and efficient mixed finite element models for shell analysis, identification of equivalent mixed and purely displacement models, and determination of the advantages of using mixed models; and effective computational models for large-rotation nonlinear problems, based on a total Lagrangian description of the deformation are included.

Prevention of myopia by partial correction of hyperopia: a twins study.

PubMed

Medina, Antonio

2018-04-01

To confirm the prediction of emmetropization feedback theory that myopia can be prevented by correcting the hyperopia of a child at risk of becoming myopic. We conducted such myopia prevention treatment with twins at risk. Their hyperopia was partially corrected by one half at age 7 and in subsequent years until age 16. Hyperopia progressively decreased in all eyes as expected. None of the twins developed myopia. The spherical equivalent refractions of the followed eyes were +1 and +1.25 D at age 16. Feedback theory accurately predicted these values. The treatment of the twins with partial correction of their hyperopia was successful. Prevention of myopia with this technique is relatively simple and powerful. The use of this myopia prevention treatment has no adverse effects. This prevention treatment is indicated in children with a hyperopic reserve at risk of developing myopia.

Development of AC impedance methods for evaluating corroding metal surfaces and coatings

NASA Technical Reports Server (NTRS)

Knockemus, Ward

1986-01-01

In an effort to investigate metal surface corrosion and the breakdown of metal protective coatings the AC Impedance Method was applied to zinc chromate primer coated 2219-T87 aluminum. The model 368-1 AC Impedance Measurement System recently acquired by the MSFC Corrosion Research Branch was used to monitor changing properties of coated aluminum disks immersed in 3.5% NaCl buffered at ph 5.5 over three to four weeks. The DC polarization resistance runs were performed on the same samples. The corrosion system can be represented by an electronic analog called an equivalent circuit that consists of transistors and capacitors in specific arrangements. This equivalent circuit parallels the impedance behavior of the corrosion system during a frequency scan. Values for resistances and capacities that can be assigned in the equivalent circuit following a least squares analysis of the data describe changes that occur on the corroding metal surface and in the protective coating. A suitable equivalent circuit was determined that predicts the correct Bode phase and magnitude for the experimental sample. The DC corrosion current density data are related to equivalent circuit element parameters.

The corrosion mechanisms for primer coated 2219-T87 aluminum

NASA Technical Reports Server (NTRS)

Danford, Merlin D.; Knockemus, Ward W.

1987-01-01

To investigate metal surface corrosion and the breakdown of metal protective coatings, the ac Impedance Method was applied to zinc chromate primer coated 2219-T87 aluminum. The EG&GPARC Model 368 ac Impedance Measurement System, along with dc measurements with the same system using the Polarization Resistance Method, was used to monitor changing properties of coated aluminum disks immersed in 3.5 percent NaCl solutions buffered at pH 5.5 and pH 8.2 over periods of 40 days each. The corrosion system can be represented by an electronic analog called an equivalent circuit consisting of resistors and capacitors in specific arrangements. This equivalent circuit parallels the impedance behavior of the corrosion system during a frequency scan. Values for resistances and capacitances, that can be assigned in the equivalent circuit following a least squares analysis of the data, describe changes occurring on the corroding metal surface and in the protective coatings. A suitable equivalent circuit has been determined which predicts the correct Bode phase and magnitude for the experimental sample. The dc corrosion current density data are related to equivalent circuit element parameters.

Affordance Equivalences in Robotics: A Formalism

PubMed Central

Andries, Mihai; Chavez-Garcia, Ricardo Omar; Chatila, Raja; Giusti, Alessandro; Gambardella, Luca Maria

2018-01-01

Automatic knowledge grounding is still an open problem in cognitive robotics. Recent research in developmental robotics suggests that a robot's interaction with its environment is a valuable source for collecting such knowledge about the effects of robot's actions. A useful concept for this process is that of an affordance, defined as a relationship between an actor, an action performed by this actor, an object on which the action is performed, and the resulting effect. This paper proposes a formalism for defining and identifying affordance equivalence. By comparing the elements of two affordances, we can identify equivalences between affordances, and thus acquire grounded knowledge for the robot. This is useful when changes occur in the set of actions or objects available to the robot, allowing to find alternative paths to reach goals. In the experimental validation phase we verify if the recorded interaction data is coherent with the identified affordance equivalences. This is done by querying a Bayesian Network that serves as container for the collected interaction data, and verifying that both affordances considered equivalent yield the same effect with a high probability. PMID:29937724

Hydrogen generator, via catalytic partial oxidation of methane for fuel cells

NASA Astrophysics Data System (ADS)

Recupero, Vincenzo; Pino, Lidia; Di Leonardo, Raffaele; Lagana', Massimo; Maggio, Gaetano

It is well known that the most acknowledged process for generation of hydrogen for fuel cells is based upon the steam reforming of methane or natural gas. A valid alternative could be a process based on partial oxidation of methane, since the process is mildly exothermic and therefore not energy intensive. Consequently, great interest is expected from conversion of methane into syngas, if an autothermal, low energy intensive, compact and reliable process could be developed. This paper covers the activities, performed by the CNR Institute of Transformation and Storage of Energy (CNR-TAE), on theoretical and experimental studies for a compact hydrogen generator, via catalytic selective partial oxidation of methane, integrated with second generation fuel cells (EC-JOU2 contract). In particular, the project focuses the attention on methane partial oxidation via heterogeneous selective catalysts, in order to: demonstrate the basic catalytic selective partial oxidation of methane (CSPOM) technology in a subscale prototype, equivalent to a nominal output of 5 kWe; develop the CSPOM technology for its application in electric energy production by means of fuel cells; assess, by a balance of plant analysis, and a techno-economic evaluation, the potential benefits of the CSPOM for different categories of fuel cells.

Geochemistry of ultramafic xenoliths from Kapfenstein, Austria: evidence for a variety of upper mantle processes

NASA Astrophysics Data System (ADS)

Kurat, G.; Palme, H.; Spettel, B.; Baddenhausen, Hildegard; Hofmeister, H.; Palme, Christl; Wänke, H.

1980-01-01

Major, minor, and trace element contents have been determined in seven ultramafic xenoliths, the host basanite, and some mineral separates from xenoliths from Kapfenstein, Austria. Most of the xenoliths represent residues after extraction of different amounts of basaltic liquid. Within the sequence Iherzolite to harzburgite contents of Al, Ca, Ti, Na, Sc, V, Cr and the HREE decrease systematically with increasing Mg/Fe and decreasing Yb/Sc. Although all samples are depleted in highly incompatible elements, the less depleted end of our suite very closely approaches the chondritic Yb/Sc ratio and consequently the primitive upper mantle composition. Chromium behaved as a non-refractory element. Consequently it should have higher abundances in basalts than observed, suggesting that most basalts experienced Cr fractionation by chromite separation during ascent. Several processes have been active in addition to partial melting within the upper mantle beneath Kapfenstein: (1) a hornblendite has been identified as wet alkali-basaltic mobilisate; (2) an amphibole Iherzolite is the product of alkali-basalt metasomatism of a common depleted Iherzolite; (3) two amphibole Iherzolites contain evidence for rather pure water metasomatism of normal depleted Iherzolites; (4) a garnet-spinel websterite was a tholeiitic liquid trapped within the upper mantle and which suffered a subsequent partial melting event (partial remobilization of a mobilisate). (5) Abundances of highly incompatible elements are generally very irregular, indicating contamination of upper mantle rocks by percolating liquids (in the mantle). Weathering is an important source of contamination: e.g. U mobilization by percolating groundwater. Contamination of the xenoliths by the host basanite liquid can only amount to approximately 5.5 × 10 -4 parts. Distributions of minor and trace elements between different minerals apparently reflect equilibrium and vary with equilibration temperature.

Numerical analysis of partially molten splat during thermal spray process using the finite element method

NASA Astrophysics Data System (ADS)

Zirari, M.; Abdellah El-Hadj, A.; Bacha, N.

2010-03-01

A finite element method is used to simulate the deposition of the thermal spray coating process. A set of governing equations is solving by a volume of fluid method. For the solidification phenomenon, we use the specific heat method (SHM). We begin by comparing the present model with experimental and numerical model available in the literature. In this study, completely molten or semi-molten aluminum particle impacts a H13 tool steel substrate is considered. Next we investigate the effect of inclination of impact of a partially molten particle on flat substrate. It was found that the melting state of the particle has great effects on the morphologies of the splat.

Exploring equivalence domain in nonlinear inverse problems using Covariance Matrix Adaption Evolution Strategy (CMAES) and random sampling

NASA Astrophysics Data System (ADS)

Grayver, Alexander V.; Kuvshinov, Alexey V.

2016-05-01

This paper presents a methodology to sample equivalence domain (ED) in nonlinear partial differential equation (PDE)-constrained inverse problems. For this purpose, we first applied state-of-the-art stochastic optimization algorithm called Covariance Matrix Adaptation Evolution Strategy (CMAES) to identify low-misfit regions of the model space. These regions were then randomly sampled to create an ensemble of equivalent models and quantify uncertainty. CMAES is aimed at exploring model space globally and is robust on very ill-conditioned problems. We show that the number of iterations required to converge grows at a moderate rate with respect to number of unknowns and the algorithm is embarrassingly parallel. We formulated the problem by using the generalized Gaussian distribution. This enabled us to seamlessly use arbitrary norms for residual and regularization terms. We show that various regularization norms facilitate studying different classes of equivalent solutions. We further show how performance of the standard Metropolis-Hastings Markov chain Monte Carlo algorithm can be substantially improved by using information CMAES provides. This methodology was tested by using individual and joint inversions of magneotelluric, controlled-source electromagnetic (EM) and global EM induction data.

The calculation of the contributions to low energy e+H2 scattering from sigma u+ and Pion u symmetries using the Kohn variational method

NASA Technical Reports Server (NTRS)

Armour, E. A. G.; Baker, D. J.; Plummer, M.

1990-01-01

Above incident energies of about 2 eV, the contribution to the total cross section in positron+H2 scattering from the sigma g+ symmetry is insufficient to account for the experimental value. Calculations carried out of the lowest partial waves of sigma u+ symmetry and Pion u symmetry using the Kohn variational method are described. The contributions to the total cross section from the two equivalent partial waves of Pion u symmetry significantly reduce the discrepancy with experiment up to incident energies of 4 to 5 eV. Comparisons are made with recent R-matrix calculations performed by Danby and Tennyson.

Lumped element filters for electronic warfare systems

NASA Astrophysics Data System (ADS)

Morgan, D.; Ragland, R.

1986-02-01

Increasing demands which future generations of electronic warfare (EW) systems are to satisfy include a reduction in the size of the equipment. The present paper is concerned with lumped element filters which can make a significant contribution to the downsizing of advanced EW systems. Lumped element filter design makes it possible to obtain very small package sizes by utilizing classical low frequency inductive and capacitive components which are small compared to the size of a wavelength. Cost-effective, temperature-stable devices can be obtained on the basis of new design techniques. Attention is given to aspects of design flexibility, an interdigital filter equivalent circuit diagram, conditions for which the use of lumped element filters can be recommended, construction techniques, a design example, and questions regarding the application of lumped element filters to EW processing systems.

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

Giunta, G.; Belouettar, S.

In this paper, the static response of three-dimensional beams made of functionally graded materials is investigated through a family of hierarchical one-dimensional finite elements. A wide variety of elements is proposed differing by the kinematic formulation and the number of nodes per elements along the beam axis. Elements’ stiffness matrix and load vector are derived in a unified nuclear form that does not depend upon the a priori expansion order over the cross-section nor the finite element approximation along the beam axis. Results are validated towards three-dimensional finite element models as well as equivalent Navier-type analytical solutions. The numerical investigationsmore » show that accurate and efficient solutions (when compared with full three-dimensional FEM solutions) can be obtained by the proposed family of hierarchical one-dimensional elements’ family.« less

3D-Finite element analysis of molars restored with endocrowns and posts during masticatory simulation.

PubMed

Dejak, Beata; Młotkowski, Andrzej

2013-12-01

The objective was to compare equivalent stresses in molars restored with endocrowns as well as posts and cores during masticatory simulation using finite element analysis. Four three-dimensional models of first mandibular molars were created: A - intact tooth; B - tooth restored by ceramic endocrown; C - tooth with FRC posts, composite core and ceramic crown; D - tooth with cast post and ceramic crown. The study was performed using finite element analysis, with contact elements. The computer simulations of mastication were conducted. The equivalent stresses of modified von Mises failure criterion (mvM) in models were calculated, Tsai-Wu index for FRC post was determinate. Maximal values of the stresses in the ceramic, cement and dentin were compared between models and to strength of the materials. Contact stresses in the cement-tissue adhesive interface around restorations were considered as well. During masticatory simulation, the lowest mvM stresses in dentin arisen in molar restored with endocrown (Model B). Maximal mvM stress values in structures of restored molar were 23% lower than in the intact tooth. The mvM stresses in the endocrown did not exceed the tensile strength of ceramic. In the molar with an FRC posts (Model C), equivalent stress values in dentin increased by 42% versus Model B. In ceramic crown of Model C the stresses were 31% higher and in the resin luting cement were 61% higher than in the tooth with endocrown. Tensile contact stresses in the adhesive cement-dentin interface around FRC posts achieved 4 times higher values than under endocrown and shear stresses increased twice. The contact stress values around the appliances were several time smaller than cement-dentin bond strength. Teeth restored by endocrowns are potentially more resistant to failure than those with FRC posts. Under physiological loads, ceramic endocrowns ideally cemented in molars should not be demaged or debonded. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Design of HIFU Transducers for Generating Specified Nonlinear Ultrasound Fields.

PubMed

Rosnitskiy, Pavel B; Yuldashev, Petr V; Sapozhnikov, Oleg A; Maxwell, Adam D; Kreider, Wayne; Bailey, Michael R; Khokhlova, Vera A

2017-02-01

Various clinical applications of high-intensity focused ultrasound have different requirements for the pressure levels and degree of nonlinear waveform distortion at the focus. The goal of this paper is to determine transducer design parameters that produce either a specified shock amplitude in the focal waveform or specified peak pressures while still maintaining quasi-linear conditions at the focus. Multiparametric nonlinear modeling based on the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation with an equivalent source boundary condition was employed. Peak pressures, shock amplitudes at the focus, and corresponding source outputs were determined for different transducer geometries and levels of nonlinear distortion. The results are presented in terms of the parameters of an equivalent single-element spherically shaped transducer. The accuracy of the method and its applicability to cases of strongly focused transducers were validated by comparing the KZK modeling data with measurements and nonlinear full diffraction simulations for a single-element source and arrays with 7 and 256 elements. The results provide look-up data for evaluating nonlinear distortions at the focus of existing therapeutic systems as well as for guiding the design of new transducers that generate specified nonlinear fields.

Using of explosive technologies for development of a compact current-limiting device for operation on 110 kV class systems

NASA Astrophysics Data System (ADS)

Shurupov, A. V.; Shurupov, M. A.; Kozlov, A. A.; Kotov, A. V.

2016-11-01

This paper considers the possibility of creating on new physical principles a highspeed current-limiting device (CLD) for the networks with voltage of 110 kV, namely, on the basis of the explosive switching elements. The device is designed to limit the steady short-circuit current to acceptable values for the time does not exceed 3 ms at electric power facilities. The paper presents an analysis of the electrical circuit of CLD. The main features of the scheme are: a new high-speed switching element with high regenerating voltage; fusible switching element that enables to limit the overvoltage after sudden breakage of network of the explosive switch; non-inductive resistor with a high heat capacity and a special reactor with operating time less than 1 s. We analyzed the work of the CLD with help of special software PSPICE, which is based on the equivalent circuit of single-phase short circuit to ground in 110 kV network. Analysis of the equivalent circuit operation CLD shows its efficiency and determines the CLD as a perspective direction of the current-limiting devices of new generation.

Solving transient acoustic boundary value problems with equivalent sources using a lumped parameter approach.

PubMed

Fahnline, John B

2016-12-01

An equivalent source method is developed for solving transient acoustic boundary value problems. The method assumes the boundary surface is discretized in terms of triangular or quadrilateral elements and that the solution is represented using the acoustic fields of discrete sources placed at the element centers. Also, the boundary condition is assumed to be specified for the normal component of the surface velocity as a function of time, and the source amplitudes are determined to match the known elemental volume velocity vector at a series of discrete time steps. Equations are given for marching-on-in-time schemes to solve for the source amplitudes at each time step for simple, dipole, and tripole source formulations. Several example problems are solved to illustrate the results and to validate the formulations, including problems with closed boundary surfaces where long-time numerical instabilities typically occur. A simple relationship between the simple and dipole source amplitudes in the tripole source formulation is derived so that the source radiates primarily in the direction of the outward surface normal. The tripole source formulation is shown to eliminate interior acoustic resonances and long-time numerical instabilities.

Bi-layer graphene structure with non-equivalent planes: Magnetic properties study

NASA Astrophysics Data System (ADS)

Mhirech, A.; Aouini, S.; Alaoui-Ismaili, A.; Bahmad, L.

2018-05-01

In this paper, we study the magnetic properties of a ferromagnetic bi-layer graphene structure with non-equivalent planes. The geometry of the studied system is formed by two layers (A) and (B) consisting of the spins σ = 1 / 2 and S = 1 . For this purpose, the influence of the coupling exchange interactions, the external magnetic and the crystal fields are investigated and presented as well as the ground state phase diagrams. The Monte Carlo simulations have been used to examine the behavior of the partial and the total magnetizations as a function of the system parameters. These effects on the compensation and critical temperatures behavior are also presented in different phase diagrams, for the studied system.

Finite-element grid improvement by minimization of stiffness matrix trace

NASA Technical Reports Server (NTRS)

Kittur, Madan G.; Huston, Ronald L.; Oswald, Fred B.

1989-01-01

A new and simple method of finite-element grid improvement is presented. The objective is to improve the accuracy of the analysis. The procedure is based on a minimization of the trace of the stiffness matrix. For a broad class of problems this minimization is seen to be equivalent to minimizing the potential energy. The method is illustrated with the classical tapered bar problem examined earlier by Prager and Masur. Identical results are obtained.

Finite-element grid improvement by minimization of stiffness matrix trace

NASA Technical Reports Server (NTRS)

Kittur, Madan G.; Huston, Ronald L.; Oswald, Fred B.

1987-01-01

A new and simple method of finite-element grid improvement is presented. The objective is to improve the accuracy of the analysis. The procedure is based on a minimization of the trace of the stiffness matrix. For a broad class of problems this minimization is seen to be equivalent to minimizing the potential energy. The method is illustrated with the classical tapered bar problem examined earlier by Prager and Masur. Identical results are obtained.

An Airborne Radar Model For Non-Uniformly Spaced Antenna Arrays

DTIC Science & Technology

2006-03-01

Department of Defense, or the United States Government . AFIT-GE-ENG-06-58 An Airborne Radar Model For Non-Uniformly Spaced Antenna Arrays THESIS Presented...different circular arrays, one containing 24 elements and one containing 15 elements. The circular array per- formance is compared to that of a 6 × 6...model and compared to the radar model of [5, 6, 13]. The two models are mathematically equivalent when the uniformly spaced array is linear. The two

Partial extinction of a conditioned context enhances preference for elements previously associated with cocaine but not with chocolate.

PubMed

Orsini, C; Bonito-Oliva, A; Montanari, C; Conversi, D; Cabib, S

2013-08-15

Drug-associated stimuli are crucial to reinstatement of drug-seeking after periods of abstinence, representing a central problem in treatment of addiction. The present study investigated the influence of partial extinction of the conditioned context on the expression of conditioned place preference (CPP). Mice of the inbred DBA/2J strain were conditioned with cocaine or chocolate in a context identified by multiple elements (A+B) and subsequently CPP expression was evaluated in a context containing only one element (A or B) or both (A+B). Cocaine- and chocolate-conditioned mice showed CPP in presence of the original compound stimulus. However, cocaine-conditioned mice did not show CPP when tested in A or B context, while chocolate-conditioned mice did show CPP to single element context. After conditioning mice were exposed to extinction training of the context A or B and then tested for CPP 1 and 9 days after the end of the extinction (days 9 and 18). Cocaine-conditioned mice showed CPP 9 days after extinction while chocolate-conditioned mice were relatively insensitive to the extinction procedure on day 1 after extinction, but they did not show CPP for the partial or the original compound 9 days after extinction. Cocaine-conditioned mice not submitted to the extinction training (simple passage of time) or submitted to a Sham-extinction procedure (saline injections and confinement in a new environment) did not show CPP on day 9 or 18. Cocaine-conditioned mice exposed to extinction training showed increased c-Fos expression in several brain areas in comparison to mice exposed to Sham-extinction. The extinction procedure did not specifically reduce behavioral sensitization. The results suggest that extinction training involving only elements of a drug-associated context can result in increased associative strength of those elements. © 2013.

A novel lightweight Fizeau infrared interferometric imaging system

NASA Astrophysics Data System (ADS)

Hope, Douglas A.; Hart, Michael; Warner, Steve; Durney, Oli; Romeo, Robert

2016-05-01

Aperture synthesis imaging techniques using an interferometer provide a means to achieve imagery with spatial resolution equivalent to a conventional filled aperture telescope at a significantly reduced size, weight and cost, an important implication for air- and space-borne persistent observing platforms. These concepts have been realized in SIRII (Space-based IR-imaging interferometer), a new light-weight, compact SWIR and MWIR imaging interferometer designed for space-based surveillance. The sensor design is configured as a six-element Fizeau interferometer; it is scalable, light-weight, and uses structural components and main optics made of carbon fiber replicated polymer (CFRP) that are easy to fabricate and inexpensive. A three-element prototype of the SIRII imager has been constructed. The optics, detectors, and interferometric signal processing principles draw on experience developed in ground-based astronomical applications designed to yield the highest sensitivity and resolution with cost-effective optical solutions. SIRII is being designed for technical intelligence from geo-stationary orbit. It has an instantaneous 6 x 6 mrad FOV and the ability to rapidly scan a 6x6 deg FOV, with a minimal SNR. The interferometric design can be scaled to larger equivalent filled aperture, while minimizing weight and costs when compared to a filled aperture telescope with equivalent resolution. This scalability in SIRII allows it address a range of IR-imaging scenarios.

Experimental verification of a thermal equivalent circuit dynamic model on an extended range electric vehicle battery pack

NASA Astrophysics Data System (ADS)

Ramotar, Lokendra; Rohrauer, Greg L.; Filion, Ryan; MacDonald, Kathryn

2017-03-01

The development of a dynamic thermal battery model for hybrid and electric vehicles is realized. A thermal equivalent circuit model is created which aims to capture and understand the heat propagation from the cells through the entire pack and to the environment using a production vehicle battery pack for model validation. The inclusion of production hardware and the liquid battery thermal management system components into the model considers physical and geometric properties to calculate thermal resistances of components (conduction, convection and radiation) along with their associated heat capacity. Various heat sources/sinks comprise the remaining model elements. Analog equivalent circuit simulations using PSpice are compared to experimental results to validate internal temperature nodes and heat rates measured through various elements, which are then employed to refine the model further. Agreement with experimental results indicates the proposed method allows for a comprehensive real-time battery pack analysis at little computational expense when compared to other types of computer based simulations. Elevated road and ambient conditions in Mesa, Arizona are simulated on a parked vehicle with varying quiescent cooling rates to examine the effect on the diurnal battery temperature for longer term static exposure. A typical daily driving schedule is also simulated and examined.

The abundance of interstellar sulphur and zinc in high density sight-lines

NASA Technical Reports Server (NTRS)

Harris, A. W.; Mashesse, J. M.

1986-01-01

On the basis of early absorption line studies of individual lines of sight with the Copernicus satellite, chlorine, sulphur and zinc were classed together as elements which showed little or no depletion, relative to hydrogen, in the interstellar medium. The abundances of other less volatile elements, such as Fe and Mg were found to vary widely from one sight-line to another with gas-phase abundances in some cases being orders of magnitude below their solar counterparts. Detailed studies are reported of the depletion/density behavior of two other volatile elements which were previously considered to be virtually undepleted, S and Zn, using equivalent width data from both Copernicus and IUE observations. The results provide further evidence that the established dependence of depletion on n bar (H) extends to volatile elements and show that their use as tracers of metallicity, or for estimating hydrogen column densities, may lead to large errors in sight-lines through dense regions. It now appears that such elements may take part in the surface chemistry of grains and be important constituents of grain mantle material, although they probably do not contribute significantly to the bulk mass of grains. Due to the very similar atomic masses and ionization potentials of sulphur and phosphorous, the thermal velocity distributions of the singly ionized species of these elements in interstellar clouds should be very similar. However, a comparison of Doppler widths (b-values) derived for SIT and PIT in the same sight-lines from the Bohlin et al Copernicus equivalent width measurements has revealed an unexpected systematic discrepancy of a factor of approx. 1.7. This Discrepancy indicates that the normally adopted oscillators strengths of the PII lambda lambda 1153 and 1302 A lines may require revision.

Fin Stabilizers As Maneuver Control Surfaces

DTIC Science & Technology

2003-12-01

function with the first three non-zero terms of its Taylor Series yields: | | | |= + +hyd u u u vrX X u X u u X vr (2.8) (2.9...For example, vrX is the equivalent, in Leibniz’ notation of 2 X X r v r v ∂ ∂ ∂= ∂ ∂ ∂ ∂    . Each partial derivative is treated as a constant

When Is All Understood and Done? The Psychological Reality of the Recognition Point

ERIC Educational Resources Information Center

Bolte, Jens; Uhe, Mechtild

2004-01-01

Using lexical decision, the effects of primes of different length on spoken word recognition were evaluated in three partial repetition priming experiments. Prime length was determined via gating (Experiments 1a and 2a). It was shorter than, equivalent to, or longer than the recognition point (RP), or a complete word. In Experiments 1b and 1c,…

Equivalent-Continuum Modeling of Nano-Structured Materials

NASA Technical Reports Server (NTRS)

Odegard, Gregory M.; Gates, Thomas S.; Nicholson, Lee M.; Wise, Kristopher E.

2001-01-01

A method has been developed for modeling structure-property relationships of nano-structured materials. This method serves as a link between computational chemistry and solid mechanics by substituting discrete molecular structures with an equivalent-continuum model. It has been shown that this substitution may be accomplished by equating the vibrational potential energy of a nano-structured material with the strain energy of representative truss and continuum models. As an important example with direct application to the development and characterization of single-walled carbon nanotubes, the model has been applied to determine the effective continuum geometry of a graphene sheet. A representative volume element of the equivalent-continuum model has been developed with an effective thickness. This effective thickness has been shown to be similar to, but slightly smaller than, the interatomic spacing of graphite.

Modelling nonlinearity in piezoceramic transducers: From equations to nonlinear equivalent circuits.

PubMed

Parenthoine, D; Tran-Huu-Hue, L-P; Haumesser, L; Vander Meulen, F; Lematre, M; Lethiecq, M

2011-02-01

Quadratic nonlinear equations of a piezoelectric element under the assumptions of 1D vibration and weak nonlinearity are derived by the perturbation theory. It is shown that the nonlinear response can be represented by controlled sources that are added to the classical hexapole used to model piezoelectric ultrasonic transducers. As a consequence, equivalent electrical circuits can be used to predict the nonlinear response of a transducer taking into account the acoustic loads on the rear and front faces. A generalisation of nonlinear equivalent electrical circuits to cases including passive layers and propagation media is then proposed. Experimental results, in terms of second harmonic generation, on a coupled resonator are compared to theoretical calculations from the proposed model. Copyright © 2010 Elsevier B.V. All rights reserved.

Gaussian intrinsic entanglement for states with partial minimum uncertainty

NASA Astrophysics Data System (ADS)

Mišta, Ladislav; Baksová, Klára

2018-01-01

We develop a recently proposed theory of a quantifier of bipartite Gaussian entanglement called Gaussian intrinsic entanglement (GIE) [L. Mišta, Jr. and R. Tatham, Phys. Rev. Lett. 117, 240505 (2016), 10.1103/PhysRevLett.117.240505]. Gaussian intrinsic entanglement provides a compromise between computable and physically meaningful entanglement quantifiers and so far it has been calculated for two-mode Gaussian states including all symmetric partial minimum-uncertainty states, weakly mixed asymmetric squeezed thermal states with partial minimum uncertainty, and weakly mixed symmetric squeezed thermal states. We improve the method of derivation of GIE and show that all previously derived formulas for GIE of weakly mixed states in fact hold for states with higher mixedness. In addition, we derive analytical formulas for GIE for several other classes of two-mode Gaussian states with partial minimum uncertainty. Finally, we show that, like for all previously known states, also for all currently considered states the GIE is equal to Gaussian Rényi-2 entanglement of formation. This finding strengthens a conjecture about the equivalence of GIE and Gaussian Rényi-2 entanglement of formation for all bipartite Gaussian states.

Experimental and geochemical evidence for derivation of the El Capitan Granite, California, by partial melting of hydrous gabbroic lower crust

USGS Publications Warehouse

Ratajeski, K.; Sisson, T.W.; Glazner, A.F.

2005-01-01

Partial melting of mafic intrusions recently emplaced into the lower crust can produce voluminous silicic magmas with isotopic ratios similar to their mafic sources. Low-temperature (825 and 850??C) partial melts synthesized at 700 MPa in biotite-hornblende gabbros from the central Sierra Nevada batholith (Sisson et al. in Contrib Mineral Petrol 148:635-661, 2005) have major-element and modeled trace-element (REE, Rb, Ba, Sr, Th, U) compositions matching those of the Cretaceous El Capitan Granite, a prominent granite and silicic granodiorite pluton in the central part of the Sierra Nevada batholith (Yosemite, CA, USA) locally mingled with coeval, isotopically similar quartz diorite through gabbro intrusions (Ratajeski et al. in Geol Soc Am Bull 113:1486-1502, 2001). These results are evidence that the El Capitan Granite, and perhaps similar intrusions in the Sierra Nevada batholith with lithospheric-mantle-like isotopic values, were extracted from LILE-enriched, hydrous (hornblende-bearing) gabbroic rocks in the Sierran lower crust. Granitic partial melts derived by this process may also be silicic end members for mixing events leading to large-volume intermediate composition Sierran plutons such as the Cretaceous Lamarck Granodiorite. Voluminous gabbroic residues of partial melting may be lost to the mantle by their conversion to garnet-pyroxene assemblages during batholithic magmatic crustal thickening. ?? Springer-Verlag 2005.

Partial melting of TTG gneisses: crustal contamination and the production of granitic melts

NASA Astrophysics Data System (ADS)

Meade, F. C.; Masotta, M.; Troll, V. R.; Freda, C.; Johnson, T. E.; Dahren, B.

2011-12-01

Understanding partial melting of ancient TTG gneiss terranes is crucial when considering crustal contamination in volcanic systems, as these rocks are unlikely to melt completely at magmatic temperatures (1000-1200 °C) and crustal pressures (<500 MPa). Variations in the bulk composition of the gneiss, magma temperature, pressure (depth) and the composition and abundance of any fluids present will produce a variety of melt compositions, from partial melts enriched in incompatible elements to more complete melts, nearing the bulk chemistry of the parent gneiss. We have used piston cylinder experiments to simulate partial melting in a suite of 12 gneisses from NW Scotland (Lewisian) and Eastern Greenland (Ammassalik, Liverpool Land) under magma chamber temperature and pressure conditions (P=200 MPa, T=975 °C). These gneisses form the basement to much of the North Atlantic Igneous Province, where crustal contamination of magmas was commonplace but the composition of the crustal partial melts are poorly constrained [1]. The experiments produced partial melts in all samples (e.g. Fig 1). Electron microprobe analyses of glasses indicate they are compositionally heterogeneous and are significantly different from the whole rock chemistry of the parent gneisses. The melts have variably evolved compositions but are typically trachy-dacitic to rhyolitic (granitic). This integrated petrological, experimental and in-situ geochemical approach allows quantification of the processes of partial melting of TTG gneiss in a volcanic context, providing accurate major/trace element and isotopic (Sr, Pb) end-members for modeling crustal contamination. The experimental melts and restites will be compared geochemically with a suite of natural TTG gneisses, providing constraints on the extent to which the gneisses have produced and subsequently lost melt. [1] Geldmacher et al. (2002) Scottish Journal of Geology, v.38, p.55-61.

The Mean Metal-line Absorption Spectrum of Damped Ly α Systems in BOSS

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

Mas-Ribas, Lluís; Miralda-Escudé, Jordi; Pérez-Ràfols, Ignasi

We study the mean absorption spectrum of the Damped Ly α (DLA) population at z ∼ 2.6 by stacking normalized, rest-frame-shifted spectra of ∼27,000 DLA systems from the DR12 of the Baryon Oscillation Spectroscopic Survey (BOSS)/SDSS-III. We measure the equivalent widths of 50 individual metal absorption lines in five intervals of DLA hydrogen column density, five intervals of DLA redshift, and overall mean equivalent widths for an additional 13 absorption features from groups of strongly blended lines. The mean equivalent width of low-ionization lines increases with N {sub H} {sub i}, whereas for high-ionization lines the increase is much weaker.more » The mean metal line equivalent widths decrease by a factor ∼1.1–1.5 from z ∼ 2.1 to z ∼ 3.5, with small or no differences between low- and high-ionization species. We develop a theoretical model, inspired by the presence of multiple absorption components observed in high-resolution spectra, to infer mean metal column densities from the equivalent widths of partially saturated metal lines. We apply this model to 14 low-ionization species and to Al iii, S iii, Si iii, C iv, Si iv, N v, and O vi. We use an approximate derivation for separating the equivalent width contributions of several lines to blended absorption features, and infer mean equivalent widths and column densities from lines of the additional species N i, Zn ii, C ii*, Fe iii, and S iv. Several of these mean column densities of metal lines in DLAs are obtained for the first time; their values generally agree with measurements of individual DLAs from high-resolution, high signal-to-noise ratio spectra when they are available.« less

Comparison of sodium, potassium, calcium, magnesium, zinc, copper and iron concentrations of elements in 24-h urine and spot urine in hypertensive patients with healthy renal function.

PubMed

Zhang, Tianjing; Chang, Xiaoyu; Liu, Wanlu; Li, Xiaoxia; Wang, Faxuan; Huang, Liping; Liao, Sha; Liu, Xiuying; Zhang, Yuhong; Zhao, Yi

2017-12-01

Sodium, potassium, calcium, magnesium, zinc, copper and iron are associated with the sequela of hypertension. The most reliable method for testing those elements is by collecting 24-h urine samples. However, this is cumbersome and collection of spot urine is more convenient in some circumstance. The aim of this study was to compare the concentrations of different elements in 24-h urine and spot urine. Data was collected from a sub-study of China Salt Substitute and Stroke Study. 240 participants were recruited randomly from 12 villages in two counties in Ningxia, China. Both spot and 24-h urine specimens were collected from each patient. Routine urine test was conducted, and concentration of elements was measured using microwave digestion and Inductively Coupled Plasma-Optical Emission Spectrometry. Partial correlation analysis and Spearman correlation analysis were used to investigate the concentration of different elements and the relationship between 24- h urine and spot urine. A partial correlation in sodium, potassium, calcium, magnesium and iron was found between paired 24-h urine and spot urine samples except copper and zinc: 0.430, 0.426, 0.550, 0.221 and 0.191 respectively. Spot urine can replace 24-h urine for estimating some of the elements in hypertensive patients with normal renal function. Copyright © 2017 Elsevier GmbH. All rights reserved.

An equivalent source model of the satellite-altitude magnetic anomaly field over Australia

NASA Technical Reports Server (NTRS)

Mayhew, M. A.; Johnson, B. D.; Langel, R. A.

1980-01-01

The low-amplitude, long-wavelength magnetic anomaly field measured between 400 and 700 km elevation over Australia by the POGO satellites is modeled by means of the equivalent source technique. Magnetic dipole moments are computed for a latitude-longitude array of dipole sources on the earth's surface such that the dipoles collectively give rise to a field which makes a least squares best fit to that observed. The distribution of magnetic moments is converted to a model of apparent magnetization contrast in a layer of constant (40 km) thickness, which contains information equivalent to the lateral variation in the vertical integral of magnetization down to the Curie isotherm and can be transformed to a model of variable thickness magnetization. It is noted that the closest equivalent source spacing giving a stable solution is about 2.5 deg, corresponding to about half the mean data elevation, and that the magnetization distribution correlates well with some of the principle tectonic elements of Australia.

Setting up virgin stress conditions in discrete element models.

PubMed

Rojek, J; Karlis, G F; Malinowski, L J; Beer, G

2013-03-01

In the present work, a methodology for setting up virgin stress conditions in discrete element models is proposed. The developed algorithm is applicable to discrete or coupled discrete/continuum modeling of underground excavation employing the discrete element method (DEM). Since the DEM works with contact forces rather than stresses there is a need for the conversion of pre-excavation stresses to contact forces for the DEM model. Different possibilities of setting up virgin stress conditions in the DEM model are reviewed and critically assessed. Finally, a new method to obtain a discrete element model with contact forces equivalent to given macroscopic virgin stresses is proposed. The test examples presented show that good results may be obtained regardless of the shape of the DEM domain.

Setting up virgin stress conditions in discrete element models

PubMed Central

Rojek, J.; Karlis, G.F.; Malinowski, L.J.; Beer, G.

2013-01-01

In the present work, a methodology for setting up virgin stress conditions in discrete element models is proposed. The developed algorithm is applicable to discrete or coupled discrete/continuum modeling of underground excavation employing the discrete element method (DEM). Since the DEM works with contact forces rather than stresses there is a need for the conversion of pre-excavation stresses to contact forces for the DEM model. Different possibilities of setting up virgin stress conditions in the DEM model are reviewed and critically assessed. Finally, a new method to obtain a discrete element model with contact forces equivalent to given macroscopic virgin stresses is proposed. The test examples presented show that good results may be obtained regardless of the shape of the DEM domain. PMID:27087731

High energy forming facility

NASA Technical Reports Server (NTRS)

Ciurlionis, B.

1967-01-01

Watertight, high-explosive forming facility, 25 feet in diameter and 15 feet deep, withstands repeated explosions of 10 pounds of TNT equivalent. The shell is fabricated of high strength steel and allows various structural elements to deform or move elastically and independently while retaining structural integrity.

40 CFR 1065.1001 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-control system means any device, system, or element of design that controls or reduces the emissions of... of 1.85:1. Total hydrocarbon equivalent (THCE) means the sum of the carbon mass contributions of non....1001 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS...

40 CFR 1065.1001 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-control system means any device, system, or element of design that controls or reduces the emissions of... of 1.85:1. Total hydrocarbon equivalent (THCE) means the sum of the carbon mass contributions of non....1001 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS...

14 CFR 121.907 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... available to crewmembers, including each other, to achieve a safe and efficient flight. Curriculum outline means a listing of each segment, module, lesson, and lesson element in a curriculum, or an equivalent... continuing qualification curriculum. First Look is conducted during an AQP continuing qualification cycle to...

Band-Pass Amplifier Without Discrete Reactance Elements

NASA Technical Reports Server (NTRS)

Kleinberg, L.

1984-01-01

Inherent or "natural" device capacitance exploited. Band-Pass Circuit has input impedance of equivalent circuit at frequencies much greater than operational-amplifier rolloff frequency. Apparent inductance and capacitance arise from combined effects of feedback and reactive component of amplifier gain in frequency range.

21 CFR 807.22 - How and where to register establishments and list devices.

Code of Federal Regulations, 2010 CFR

2010-04-01

... use of the device. In lieu of form FDA-2892, tapes for computer input or hard copy computer output may by submitted if equivalent in all elements of information as specified in form FDA-2892. All formats...

Independent component analysis of EEG dipole source localization in resting and action state of brain

NASA Astrophysics Data System (ADS)

Almurshedi, Ahmed; Ismail, Abd Khamim

2015-04-01

EEG source localization was studied in order to determine the location of the brain sources that are responsible for the measured potentials at the scalp electrodes using EEGLAB with Independent Component Analysis (ICA) algorithm. Neuron source locations are responsible in generating current dipoles in different states of brain through the measured potentials. The current dipole sources localization are measured by fitting an equivalent current dipole model using a non-linear optimization technique with the implementation of standardized boundary element head model. To fit dipole models to ICA components in an EEGLAB dataset, ICA decomposition is performed and appropriate components to be fitted are selected. The topographical scalp distributions of delta, theta, alpha, and beta power spectrum and cross coherence of EEG signals are observed. In close eyes condition it shows that during resting and action states of brain, alpha band was activated from occipital (O1, O2) and partial (P3, P4) area. Therefore, parieto-occipital area of brain are active in both resting and action state of brain. However cross coherence tells that there is more coherence between right and left hemisphere in action state of brain than that in the resting state. The preliminary result indicates that these potentials arise from the same generators in the brain.

On conforming mixed finite element methods for incompressible viscous flow problems

NASA Technical Reports Server (NTRS)

Gunzburger, M. D; Nicolaides, R. A.; Peterson, J. S.

1982-01-01

The application of conforming mixed finite element methods to obtain approximate solutions of linearized Navier-Stokes equations is examined. Attention is given to the convergence rates of various finite element approximations of the pressure and the velocity field. The optimality of the convergence rates are addressed in terms of comparisons of the approximation convergence to a smooth solution in relation to the best approximation available for the finite element space used. Consideration is also devoted to techniques for efficient use of a Gaussian elimination algorithm to obtain a solution to a system of linear algebraic equations derived by finite element discretizations of linear partial differential equations.

Analysis and synthesis of distributed-lumped-active networks by digital computer

NASA Technical Reports Server (NTRS)

1973-01-01

The use of digital computational techniques in the analysis and synthesis of DLA (distributed lumped active) networks is considered. This class of networks consists of three distinct types of elements, namely, distributed elements (modeled by partial differential equations), lumped elements (modeled by algebraic relations and ordinary differential equations), and active elements (modeled by algebraic relations). Such a characterization is applicable to a broad class of circuits, especially including those usually referred to as linear integrated circuits, since the fabrication techniques for such circuits readily produce elements which may be modeled as distributed, as well as the more conventional lumped and active ones.

Equivalent-Continuum Modeling With Application to Carbon Nanotubes

NASA Technical Reports Server (NTRS)

Odegard, Gregory M.; Gates, Thomas S.; Nicholson, Lee M.; Wise, Kristopher E.

2002-01-01

A method has been proposed for developing structure-property relationships of nano-structured materials. This method serves as a link between computational chemistry and solid mechanics by substituting discrete molecular structures with equivalent-continuum models. It has been shown that this substitution may be accomplished by equating the vibrational potential energy of a nano-structured material with the strain energy of representative truss and continuum models. As important examples with direct application to the development and characterization of single-walled carbon nanotubes and the design of nanotube-based devices, the modeling technique has been applied to determine the effective-continuum geometry and bending rigidity of a graphene sheet. A representative volume element of the chemical structure of graphene has been substituted with equivalent-truss and equivalent continuum models. As a result, an effective thickness of the continuum model has been determined. This effective thickness has been shown to be significantly larger than the interatomic spacing of graphite. The effective thickness has been shown to be significantly larger than the inter-planar spacing of graphite. The effective bending rigidity of the equivalent-continuum model of a graphene sheet was determined by equating the vibrational potential energy of the molecular model of a graphene sheet subjected to cylindrical bending with the strain energy of an equivalent continuum plate subjected to cylindrical bending.

Modules and methods for all photonic computing

DOEpatents

Schultz, David R.; Ma, Chao Hung

2001-01-01

A method for all photonic computing, comprising the steps of: encoding a first optical/electro-optical element with a two dimensional mathematical function representing input data; illuminating the first optical/electro-optical element with a collimated beam of light; illuminating a second optical/electro-optical element with light from the first optical/electro-optical element, the second optical/electro-optical element having a characteristic response corresponding to an iterative algorithm useful for solving a partial differential equation; iteratively recirculating the signal through the second optical/electro-optical element with light from the second optical/electro-optical element for a predetermined number of iterations; and, after the predetermined number of iterations, optically and/or electro-optically collecting output data representing an iterative optical solution from the second optical/electro-optical element.

Structures in color space

NASA Astrophysics Data System (ADS)

Petrov, Alexander P.

1996-09-01

Classic colorimetry and the traditionally used color space do not represent all perceived colors (for example, browns look dark yellow in colorimetric conditions of observation) so, the specific goal of this work is to suggest another concept of color and to prove that the corresponding set of colors is complete. The idea of our approach attributing color to surface patches (not to the light) immediately ties all the problems of color perception and vision geometry. The equivalence relation in the linear space of light fluxes F established by a procedure of colorimetry gives us a 3D color space H. By definition we introduce a sample (sigma) (surface patch) as a linear mapping (sigma) : L yields H, where L is a subspace of F called the illumination space. A Dedekind structure of partial order can be defined in the set of the samples: two samples (alpha) and (Beta) belong to one chromatic class if ker(alpha) equals ker(Beta) and (alpha) > (Beta) if ker(alpha) ker(Beta) . The maximal elements of this chain create the chromatic class BLACK. There can be given geometrical arguments for L to be 3D and it can be proved that in this case the minimal element of the above Dedekind structure is unique and the corresponding chromatic class is called WHITE containing the samples (omega) such that ker(omega) equals {0} L. Color is defined as mapping C: H yields H and assuming color constancy the complete set of perceived colors is proved to be isomorphic to a subset C of 3 X 3 matrices. This subset is convex, limited and symmetrical with E/2 as the center of symmetry. The problem of metrization of the color space C is discussed and a color metric related to shape, i.e., to vision geometry, is suggested.

Development of a simulation model for dynamic derailment analysis of high-speed trains

NASA Astrophysics Data System (ADS)

Ling, Liang; Xiao, Xin-Biao; Jin, Xue-Song

2014-12-01

The running safety of high-speed trains has become a major concern of the current railway research with the rapid development of high-speed railways around the world. The basic safety requirement is to prevent the derailment. The root causes of the dynamic derailment of high-speed trains operating in severe environments are not easy to identify using the field tests or laboratory experiments. Numerical simulation using an advanced train-track interaction model is a highly efficient and low-cost approach to investigate the dynamic derailment behavior and mechanism of high-speed trains. This paper presents a three-dimensional dynamic model of a high-speed train coupled with a ballast track for dynamic derailment analysis. The model considers a train composed of multiple vehicles and the nonlinear inter-vehicle connections. The ballast track model consists of rails, fastenings, sleepers, ballasts, and roadbed, which are modeled by Euler beams, nonlinear spring-damper elements, equivalent ballast bodies, and continuous viscoelastic elements, in which the modal superposition method was used to reduce the order of the partial differential equations of Euler beams. The commonly used derailment safety assessment criteria around the world are embedded in the simulation model. The train-track model was then used to investigate the dynamic derailment responses of a high-speed train passing over a buckled track, in which the derailment mechanism and train running posture during the dynamic derailment process were analyzed in detail. The effects of train and track modelling on dynamic derailment analysis were also discussed. The numerical results indicate that the train and track modelling options have a significant effect on the dynamic derailment analysis. The inter-vehicle impacts and the track flexibility and nonlinearity should be considered in the dynamic derailment simulations.

A new method for the determination of very small Γγ partial widths

NASA Astrophysics Data System (ADS)

Cardella, Giuseppe; Acosta, Luis; Auditore, Lucrezia; Camaiani, Alberto; Filippo, Enrico De; Luca, Saverio De; Gelli, Nicla; Gnoffo, Brunilde; Favela, Francisco; Fornal, Bogdan; Lanzalone, Gaetano; Leoni, Silvia; Maiolino, Concetta; Martorana, Nunzia Simona; Nannini, Adriana; Norella, Sebastianella; Pagano, Angelo; Pagano, Emanuele Vincenzo; Papa, Massimo; Pirrone, Sara; Politi, Giuseppe; Porto, Francesco; Quattrocchi, Lucia; Rizzo, Francesca; Russotto, Paolo; Santonocito, Domenico; Trifirò, Antonio; Trimarchì, Marina

2018-01-01

We present a new method for the measurement of very small Γγ partial width that is important for the synthesis of elements in astrophysics. The method is based on the simultaneous detection of scattered beam, residual nucleus and decay γ rays. This method is optimized for the use of the CHIMERA detector at LNS. Experimental details are described.

Fast Boundary Element Method for acoustics with the Sparse Cardinal Sine Decomposition

NASA Astrophysics Data System (ADS)

Alouges, François; Aussal, Matthieu; Parolin, Emile

2017-07-01

This paper presents the newly proposed method Sparse Cardinal Sine Decomposition that allows fast convolution on unstructured grids. We focus on its use when coupled with finite element techniques to solve acoustic problems with the (compressed) Boundary Element Method. In addition, we also compare the computational performances of two equivalent Matlab® and Python implementations of the method. We show validation test cases in order to assess the precision of the approach. Eventually, the performance of the method is illustrated by the computation of the acoustic target strength of a realistic submarine from the Benchmark Target Strength Simulation international workshop.

Fast transient digitizer

DOEpatents

Villa, Francesco

1982-01-01

Method and apparatus for sequentially scanning a plurality of target elements with an electron scanning beam modulated in accordance with variations in a high-frequency analog signal to provide discrete analog signal samples representative of successive portions of the analog signal; coupling the discrete analog signal samples from each of the target elements to a different one of a plurality of high speed storage devices; converting the discrete analog signal samples to equivalent digital signals; and storing the digital signals in a digital memory unit for subsequent measurement or display.

On Non-Abelian Extensions of 3-Lie Algebras

NASA Astrophysics Data System (ADS)

Song, Li-Na; Makhlouf, Abdenacer; Tang, Rong

2018-04-01

In this paper, we study non-abelian extensions of 3-Lie algebras through Maurer-Cartan elements. We show that there is a one-to-one correspondence between isomorphism classes of non-abelian extensions of 3-Lie algebras and equivalence classes of Maurer-Cartan elements in a DGLA. The structure of the Leibniz algebra on the space of fundamental objects is also analyzed. Supported by National Natural Science Foundation of China under Grant No. 11471139 and National Natural Science Foundation of Jilin Province under Grant No. 20170101050JC

Detection of Bioaerosols Using Single Particle Thermal Emission Spectroscopy (First-year Report)

DTIC Science & Technology

2012-02-01

cooled MCT detector with a noise equivalent power (NEP) of 7x10(–13) W/Hz, yields a detection S/N > 13 (assuming a sufficiently cooled background). We...dispersively resolved using 190-mm Horiba spectrometer that houses a time-gated 32-element mercury cadmium telluride ( MCT ) linear array. In this report...to 10.0 ms. Minimum integration (and readout) periods for the time-gated 32-element mercury cadmium telluride ( MCT ) linear array are 10 µs. Based

Frequencies and Flutter Speed Estimation for Damaged Aircraft Wing Using Scaled Equivalent Plate Analysis

NASA Technical Reports Server (NTRS)

Krishnamurthy, Thiagarajan

2010-01-01

Equivalent plate analysis is often used to replace the computationally expensive finite element analysis in initial design stages or in conceptual design of aircraft wing structures. The equivalent plate model can also be used to design a wind tunnel model to match the stiffness characteristics of the wing box of a full-scale aircraft wing model while satisfying strength-based requirements An equivalent plate analysis technique is presented to predict the static and dynamic response of an aircraft wing with or without damage. First, a geometric scale factor and a dynamic pressure scale factor are defined to relate the stiffness, load and deformation of the equivalent plate to the aircraft wing. A procedure using an optimization technique is presented to create scaled equivalent plate models from the full scale aircraft wing using geometric and dynamic pressure scale factors. The scaled models are constructed by matching the stiffness of the scaled equivalent plate with the scaled aircraft wing stiffness. It is demonstrated that the scaled equivalent plate model can be used to predict the deformation of the aircraft wing accurately. Once the full equivalent plate geometry is obtained, any other scaled equivalent plate geometry can be obtained using the geometric scale factor. Next, an average frequency scale factor is defined as the average ratio of the frequencies of the aircraft wing to the frequencies of the full-scaled equivalent plate. The average frequency scale factor combined with the geometric scale factor is used to predict the frequency response of the aircraft wing from the scaled equivalent plate analysis. A procedure is outlined to estimate the frequency response and the flutter speed of an aircraft wing from the equivalent plate analysis using the frequency scale factor and geometric scale factor. The equivalent plate analysis is demonstrated using an aircraft wing without damage and another with damage. Both of the problems show that the scaled equivalent plate analysis can be successfully used to predict the frequencies and flutter speed of a typical aircraft wing.

Nature of size effects in compact models of field effect transistors

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

Torkhov, N. A., E-mail: trkf@mail.ru; Scientific-Research Institute of Semiconductor Devices, Tomsk 634050; Tomsk State University of Control Systems and Radioelectronics, Tomsk 634050

Investigations have shown that in the local approximation (for sizes L < 100 μm), AlGaN/GaN high electron mobility transistor (HEMT) structures satisfy to all properties of chaotic systems and can be described in the language of fractal geometry of fractional dimensions. For such objects, values of their electrophysical characteristics depend on the linear sizes of the examined regions, which explain the presence of the so-called size effects—dependences of the electrophysical and instrumental characteristics on the linear sizes of the active elements of semiconductor devices. In the present work, a relationship has been established for the linear model parameters of themore » equivalent circuit elements of internal transistors with fractal geometry of the heteroepitaxial structure manifested through a dependence of its relative electrophysical characteristics on the linear sizes of the examined surface areas. For the HEMTs, this implies dependences of their relative static (A/mm, mA/V/mm, Ω/mm, etc.) and microwave characteristics (W/mm) on the width d of the sink-source channel and on the number of sections n that leads to a nonlinear dependence of the retrieved parameter values of equivalent circuit elements of linear internal transistor models on n and d. Thus, it has been demonstrated that the size effects in semiconductors determined by the fractal geometry must be taken into account when investigating the properties of semiconductor objects on the levels less than the local approximation limit and designing and manufacturing field effect transistors. In general, the suggested approach allows a complex of problems to be solved on designing, optimizing, and retrieving the parameters of equivalent circuits of linear and nonlinear models of not only field effect transistors but also any arbitrary semiconductor devices with nonlinear instrumental characteristics.« less

Validation of High Displacement Piezoelectric Actuator Finite Element Models

NASA Technical Reports Server (NTRS)

Taleghani, B. K.

2000-01-01

The paper presents the results obtained by using NASTRAN(Registered Trademark) and ANSYS(Regitered Trademark) finite element codes to predict doming of the THUNDER piezoelectric actuators during the manufacturing process and subsequent straining due to an applied input voltage. To effectively use such devices in engineering applications, modeling and characterization are essential. Length, width, dome height, and thickness are important parameters for users of such devices. Therefore, finite element models were used to assess the effects of these parameters. NASTRAN(Registered Trademark) and ANSYS(Registered Trademark) used different methods for modeling piezoelectric effects. In NASTRAN(Registered Trademark), a thermal analogy was used to represent voltage at nodes as equivalent temperatures, while ANSYS(Registered Trademark) processed the voltage directly using piezoelectric finite elements. The results of finite element models were validated by using the experimental results.

Role of common mental and physical disorders in partial disability around the world

PubMed Central

Bruffaerts, Ronny; Vilagut, Gemma; Demyttenaere, Koen; Alonso, Jordi; AlHamzawi, Ali; Andrade, Laura Helena; Benjet, Corina; Bromet, Evelyn; Bunting, Brendan; de Girolamo, Giovanni; Florescu, Silvia; Gureje, Oye; Haro, Josep Maria; He, Yanling; Hinkov, Hristo; Hu, Chiyi; Karam, Elie G.; Lepine, Jean-Pierre; Levinson, Daphna; Matschinger, Herbert; Nakane, Yoshibumi; Ormel, Johan; Posada-Villa, Jose; Scott, Kate M.; Varghese, Matthew; Williams, David R.; Xavier, Miguel; Kessler, Ronald C.

2012-01-01

Background Mental and physical disorders are associated with total disability, but their effects on days with partial disability (i.e. the ability to perform some, but not full-role, functioning in daily life) are not well understood. Aims To estimate individual (i.e. the consequences for an individual with a disorder) and societal effects (i.e. the avoidable partial disability in the society due to disorders) of mental and physical disorders on days with partial disability around the world. Method Respondents from 26 nationally representative samples (n = 61 259, age 18+) were interviewed regarding mental and physical disorders, and day-to-day functioning. The Composite International Diagnostic Interview, version 3.0 (CIDI 3.0) was used to assess mental disorders; partial disability (expressed in full day equivalents) was assessed with the World Health Organization Disability Assessment Schedule in the CIDI 3.0. Results Respondents with disorders reported about 1.58 additional disability days per month compared with respondents without disorders. At the individual level, mental disorders (especially post-traumatic stress disorder, depression and bipolar disorder) yielded a higher number of days with disability than physical disorders. At the societal level, the population attributable risk proportion due to physical and mental disorders was 49% and 15% respectively. Conclusions Mental and physical disorders have a considerable impact on partial disability, at both the individual and at the societal level. Physical disorders yielded higher effects on partial disability than mental disorders. PMID:22539779

Partial reinforcement, extinction, and placebo analgesia

PubMed Central

Yeung, Siu Tsin Au; Colagiuri, Ben; Lovibond, Peter F.; Colloca, Luana

2014-01-01

Numerous studies indicate that placebo analgesia can be established via conditioning procedures. However, these studies have exclusively involved conditioning under continuous reinforcement. Thus, it is currently unknown whether placebo analgesia can be established under partial reinforcement and how durable any such effect would be. We tested this possibility using electro-cutaneous pain in healthy volunteers. Sixty undergraduates received placebo treatment (activation of a sham electrode) under the guise of an analgesic trial. The participants were randomly allocated to different conditioning schedules, namely continuous reinforcement (CRF), partial reinforcement (PRF), or control (no conditioning). Conditioning was achieved by surreptitiously reducing pain intensity during training when the placebo was activated compared with when it was inactive. For the CRF group, the placebo was always followed by a surreptitious reduction in pain during training. For the PRF group, the placebo was followed by a reduction in pain stimulation on 62.5% of trials only. In the test phase, pain stimulation was equivalent across placebo and no placebo trials. Both continuous and partial reinforcement produced placebo analgesia, with the magnitude of initial analgesia being larger following continuous reinforcement. However, while the placebo analgesia established under continuous reinforcement extinguished during test phase, the placebo analgesia established under partial reinforcement did not. These findings indicate that partial reinforcement can induce placebo analgesia and that these effects are more resistant to extinction than those established via continuous reinforcement. Partial reinforcement may, therefore, reflect a novel way of enhancing clinical outcomes via the placebo effect. PMID:24602997

Element Abundances in Meteorites and the Earth: Implication for the Accretion of Planetary Bodies

NASA Astrophysics Data System (ADS)

Mezger, K.; Vollstaedt, H.; Maltese, A.

2017-12-01

Essentially all known inner solar system materials show near chondritic relative abundances of refractory elements and depletion in volatile elements. To a first approximation volatile element depletion correlates with the respective condensation temperature (TC) of the elements. Possible mechanisms for this depletion are incomplete condensation and partial loss by evaporation caused by heating prior to or during the planetesimal accretion. The stable isotope compositions of almost all moderately volatile elements in different meteorite classes show only minor, or no evidence for a Rayleigh-type fractionation that could be attributed to partial condensation or evaporation. The different classes of meteorites also show that the degree of depletion in their parent bodies (i.e. mostly planetesimals) is quite variable, but nevertheless systematic. For primitive and least disturbed carbonaceous chondrites the element depletion pattern is a smooth function of TC. The accessible silicate Earth also shows this general depletion pattern, but in detail it is highly complex and requires differentiation processes that are not solely controlled by TC. If only highly lithophile elements are considered the depletion pattern of the silicate Earth reveals a step function that shows that moderately volatile lithophile elements have abundances that are ca. 0.1 times the chondritic value, irrespective of their TC. This element pattern observed for bulk silicate Earth can be modelled as a mixture of two distinct components: ca. 90% of a strongly reduced planetary body that is depleted in highly volatile elements and ca. 10% of a more volatile element rich and oxidized component. This mixture can account for the apparent Pb- paradox observed in melts derived from the silicate Earth and provides a time constraint for the mixing event, which is ca. 70 My after the beginning of the solar system. This event corresponds to the giant impact that also formed the Moon.

A randomized pilot trial of a full subsidy vs. a partial subsidy for obesity treatment.

PubMed

Tsai, Adam G; Felton, Sue; Hill, James O; Atherly, Adam J

2012-09-01

Intensive obesity treatment is mandated by federal health care reform but is costly. A partial subsidy for obesity treatment could lower the cost of treatment, without reducing its efficacy. This study sought to test whether a partial subsidy for obesity treatment would be feasible, as compared to a fully subsidized intervention. The study was a pilot randomized trial. Participants (n = 50) were primary care patients with obesity and at least one comorbid condition (diabetes, hypertension, dyslipidemia, or obstructive sleep apnea). Each participant received eight weight loss counseling visits as well as portion-controlled foods for weight loss. Participants were randomized to full subsidy or partial subsidy (2 vs. 1 meal per day provided). The primary outcome was weight change after 4 months. Secondary outcomes included changes in blood pressure, waist circumference, and health-related quality of life. Participants in the full and partial subsidy groups lost 5.9 and 5.3 kg, equivalent to 5.3% and 5.1% of initial weight, respectively (P = 0.71). Changes in secondary outcomes were similar in the two groups. A partial subsidy was feasible and induced a clinically similar amount of weight loss, compared to a full subsidy. Large-scale testing of economic incentives for weight control is merited given the federal mandate to offer weight loss counseling to obese patients.

Assessment of the performance characteristics of a prototype 12-element capacitive contact flexible microstrip applicator (CFMA-12) for superficial hyperthermia.

PubMed

Lee, W M; Gelvich, E A; van der Baan, P; Mazokhin, V N; van Rhoon, G C

2004-09-01

The electrical performance of the CFMA-12 operating at 433 MHz is assessed under laboratory conditions using a RF network analyser. From measurements of the scattering parameters of the CFMA-12 on both a multi-layered muscle- and fat/muscle-equivalent phantom, the optimal water bolus thickness, at which the transfer of the energy to the phantom configuration is maximal, is determined to be approximately 1 cm. The SAR distribution of the CFMA-12 in a multi-layered muscle-equivalent phantom is characterized using Schottky diode sheets and a TVS-600 IR camera. From the SAR measurements using the Schottky diode sheets it is shown that the contribution of the E(x) component to the SAR (SAR(x)) is maximal 7% of the contribution of the E(y)component to the SAR (SAR(y)) at different layers in both phantom configurations. The complete SAR distribution (SAR(tot)) at different depths is measured using the power pulse technique. From these measurements, it can be seen that SAR(y)at a depth of 0 cm in the muscle-equivalent phantom represents up to 80% of SAR(tot). At 1 and 2 cm depth, SAR(y) is up to 95% of SAR(tot). Therefore, in homogeneous muscle-equivalent phantoms, E(y) is the largest E-field component and measurement of SAR(y) distribution is sufficient to characterize SAR-steering performance of the CFMA-12. SAR steering measurements at 1 cm depth in the muscle-equivalent phantom show that the SAR maximum varies by 40% (1 SD) around the average value of 38.8 W kg(-1) (range 10-65 W kg(-1)) between single antenna elements. The effective fieldsize (E(50)) varies by 14% (1 SD) around the average value of 19.1 cm(2).

Electrical equivalent circuit for microstrip micro-plasma: control of EM propagation and numerical simulations.

PubMed

Mohamad, Almustafa; Tân-Hoa, Vuong; Jacques, David

2012-01-01

An approach to determine an equivalent electrical circuit of a micro planar discharge on a microstrip printed circuit is reported. The micro discharge is used to realize a dynamic microwave switching circuit. This approach is based on the measurement of the discharge current and the transmission coefficient for a given frequency 2.45 GHz. Numerical methods like FEM can be used to study the effect of plasma parameters on the propagation of electromagnetic waves through a microstrip printed circuit. Plasma behaves as flexible elements that can change its electrical proprieties such as conductivity.

Gaussian entanglement revisited

NASA Astrophysics Data System (ADS)

Lami, Ludovico; Serafini, Alessio; Adesso, Gerardo

2018-02-01

We present a novel approach to the separability problem for Gaussian quantum states of bosonic continuous variable systems. We derive a simplified necessary and sufficient separability criterion for arbitrary Gaussian states of m versus n modes, which relies on convex optimisation over marginal covariance matrices on one subsystem only. We further revisit the currently known results stating the equivalence between separability and positive partial transposition (PPT) for specific classes of Gaussian states. Using techniques based on matrix analysis, such as Schur complements and matrix means, we then provide a unified treatment and compact proofs of all these results. In particular, we recover the PPT-separability equivalence for: (i) Gaussian states of 1 versus n modes; and (ii) isotropic Gaussian states. In passing, we also retrieve (iii) the recently established equivalence between separability of a Gaussian state and and its complete Gaussian extendability. Our techniques are then applied to progress beyond the state of the art. We prove that: (iv) Gaussian states that are invariant under partial transposition are necessarily separable; (v) the PPT criterion is necessary and sufficient for separability for Gaussian states of m versus n modes that are symmetric under the exchange of any two modes belonging to one of the parties; and (vi) Gaussian states which remain PPT under passive optical operations can not be entangled by them either. This is not a foregone conclusion per se (since Gaussian bound entangled states do exist) and settles a question that had been left unanswered in the existing literature on the subject. This paper, enjoyable by both the quantum optics and the matrix analysis communities, overall delivers technical and conceptual advances which are likely to be useful for further applications in continuous variable quantum information theory, beyond the separability problem.

A Novel Two-Compartment Model for Calculating Bone Volume Fractions and Bone Mineral Densities From Computed Tomography Images.

PubMed

Lin, Hsin-Hon; Peng, Shin-Lei; Wu, Jay; Shih, Tian-Yu; Chuang, Keh-Shih; Shih, Cheng-Ting

2017-05-01

Osteoporosis is a disease characterized by a degradation of bone structures. Various methods have been developed to diagnose osteoporosis by measuring bone mineral density (BMD) of patients. However, BMDs from these methods were not equivalent and were incomparable. In addition, partial volume effect introduces errors in estimating bone volume from computed tomography (CT) images using image segmentation. In this study, a two-compartment model (TCM) was proposed to calculate bone volume fraction (BV/TV) and BMD from CT images. The TCM considers bones to be composed of two sub-materials. Various equivalent BV/TV and BMD can be calculated by applying corresponding sub-material pairs in the TCM. In contrast to image segmentation, the TCM prevented the influence of the partial volume effect by calculating the volume percentage of sub-material in each image voxel. Validations of the TCM were performed using bone-equivalent uniform phantoms, a 3D-printed trabecular-structural phantom, a temporal bone flap, and abdominal CT images. By using the TCM, the calculated BV/TVs of the uniform phantoms were within percent errors of ±2%; the percent errors of the structural volumes with various CT slice thickness were below 9%; the volume of the temporal bone flap was close to that from micro-CT images with a percent error of 4.1%. No significant difference (p >0.01) was found between the areal BMD of lumbar vertebrae calculated using the TCM and measured using dual-energy X-ray absorptiometry. In conclusion, the proposed TCM could be applied to diagnose osteoporosis, while providing a basis for comparing various measurement methods.

Reductions in biomarkers of exposure (BoE) to harmful or potentially harmful constituents (HPHCs) following partial or complete substitution of cigarettes with electronic cigarettes in adult smokers

PubMed Central

O’Connell, Grant; Graff, Donald W.; D’Ruiz, Carl D.

2016-01-01

Abstract Changes in fifteen urine, blood and exhaled breath BoEs of HPHCs representing classes of compounds reported by FDA to be significant contributors to smoking-associated disease risks were measured in 105 clinical-confined subjects following randomization and a five-day forced-switch from usual brand conventional combustible cigarettes to: (i) exclusive commercial e-cigarette use; (ii) dual-use of commercial e-cigarettes and the subject’s usual cigarette brand; or (iii) discontinued use of all tobacco or nicotine products. Levels of urinary biomarkers in subjects that completely substituted their usual cigarette with e-cigarettes were significantly lower (29–95%) after 5 days. Percent reductions in eight of nine urinary BoEs were indistinguishable to smokers who had quit smoking, except for nicotine equivalents, which declined by 25–40%. Dual users who halved self-reported daily cigarette consumption with e-cigarettes exhibited reductions (7–38%) in eight of nine urinary biomarkers, but had increase (1–20%) in nicotine equivalents. Reductions were broadly proportional to the reduced numbers of cigarettes smoked. Dual user urinary nicotine equivalents were slightly higher, but not statistically significant. After 5 days, blood nicotine biomarker levels were lower in the cessation (75–96%) and exclusive use groups (11–83%); with dual users experiencing no significant reductions. All subjects experienced significant decreases in exhaled CO. Decreases in the cessation and exclusive groups ranged from 88–89% and 27–32% in dual users. Exhaled NO increased in the cessation and exclusive groups (46–63% respectively), whereas the dual users experienced minimal changes. Overall, smokers who completely or partially substituted conventional cigarettes with e-cigarettes over five days, experienced reductions in HPHCs. PMID:27401591

Reductions in biomarkers of exposure (BoE) to harmful or potentially harmful constituents (HPHCs) following partial or complete substitution of cigarettes with electronic cigarettes in adult smokers.

PubMed

O'Connell, Grant; Graff, Donald W; D'Ruiz, Carl D

2016-07-01

Changes in fifteen urine, blood and exhaled breath BoEs of HPHCs representing classes of compounds reported by FDA to be significant contributors to smoking-associated disease risks were measured in 105 clinical-confined subjects following randomization and a five-day forced-switch from usual brand conventional combustible cigarettes to: (i) exclusive commercial e-cigarette use; (ii) dual-use of commercial e-cigarettes and the subject's usual cigarette brand; or (iii) discontinued use of all tobacco or nicotine products. Levels of urinary biomarkers in subjects that completely substituted their usual cigarette with e-cigarettes were significantly lower (29-95%) after 5 days. Percent reductions in eight of nine urinary BoEs were indistinguishable to smokers who had quit smoking, except for nicotine equivalents, which declined by 25-40%. Dual users who halved self-reported daily cigarette consumption with e-cigarettes exhibited reductions (7-38%) in eight of nine urinary biomarkers, but had increase (1-20%) in nicotine equivalents. Reductions were broadly proportional to the reduced numbers of cigarettes smoked. Dual user urinary nicotine equivalents were slightly higher, but not statistically significant. After 5 days, blood nicotine biomarker levels were lower in the cessation (75-96%) and exclusive use groups (11-83%); with dual users experiencing no significant reductions. All subjects experienced significant decreases in exhaled CO. Decreases in the cessation and exclusive groups ranged from 88-89% and 27-32% in dual users. Exhaled NO increased in the cessation and exclusive groups (46-63% respectively), whereas the dual users experienced minimal changes. Overall, smokers who completely or partially substituted conventional cigarettes with e-cigarettes over five days, experienced reductions in HPHCs.

Genesis of Augite-Bearing Ureilites: Evidence From LA-ICP-MS Analyses of Pyroxenes and Olivine

NASA Technical Reports Server (NTRS)

Herrin, J. S.; Lee, C-T. A.; Mittlefehldt, D. W.

2008-01-01

Ureilites are ultramafic achondrites composed primarily of coarse-grained low-Ca pyroxene and olivine with interstitial carbonaceous material, but a number of them contain augite [1]. Ureilites are considered to be restites after partial melting of a chondritic precursor, although at least some augite-bearing ureilites may be partially cumulate [1, 2]. In this scenario, the augite is a cumulus phase derived from a melt that infiltrated a restite composed of typical ureilite material (olivine+low-Ca pyroxene) [2]. To test this hypothesis, we examined the major and trace element compositions of silicate minerals in select augite-bearing ureilites with differing mg#. Polished thick sections of the augite-bearing ureilites ALH 84136 , EET 87511, EET 96293, LEW 88201, and META78008 and augite-free typical ureilite EET 90019 were examined by EPMA for major and minor elements and laser ablation ICP-MS (LA-ICP-MS) for trace elements, REE in particular. Although EET 87511 is reported to contain augite, the polished section that we obtained did not.

Method of forming a variable width channel

NASA Technical Reports Server (NTRS)

Andrews, James T. (Inventor)

1989-01-01

A method of forming a channel of varying width in a body comprises the steps of forming a plurality of masking elements having an opening therethrough intersecting a plurality of the elements on a surface of the body, partially flowing the elements into the opening to form a masking pattern having a variable width opening therethrough, and removing portions of the exposed body to form the channel with a sidewall having a surface contour corresponding to an edge of the masking pattern.

N-person differential games. Part 1: Duality-finite element methods

NASA Technical Reports Server (NTRS)

Chen, G.; Zheng, Q.

1983-01-01

The duality approach, which is motivated by computational needs and is done by introducing N + 1 Language multipliers is addressed. For N-person linear quadratic games, the primal min-max problem is shown to be equivalent to the dual min-max problem.

Review of ASTM Symposium on Surface Crack Growth: Models, Experiments, and Structures

DTIC Science & Technology

1990-11-01

34 Extraction of Stress-Intensity Factor from In-Plane Displacements Measured by Holographic Interferometry--J.W. Dally, C.A. Sciammarella , and I...results and finite elements and find that they are essentially equivalent. Dally, Sciammarella , and Shareef use holographic interferometry and

Multichannel conformal blocks for scattering amplitudes

NASA Astrophysics Data System (ADS)

Belitsky, A. V.

2018-05-01

By performing resummation of small fermion-antifermion pairs within the pentagon form factor program to scattering amplitudes in planar N = 4 superYang-Mills theory, we construct multichannel conformal blocks within the flux-tube picture for N-sided NMHV polygons. This procedure is equivalent to summation of descendants of conformal primaries in the OPE framework. The resulting conformal partial waves are determined by multivariable hypergeometric series of Lauricella-Saran type.

An equivalent domain integral method for three-dimensional mixed-mode fracture problems

NASA Technical Reports Server (NTRS)

Shivakumar, K. N.; Raju, I. S.

1991-01-01

A general formulation of the equivalent domain integral (EDI) method for mixed mode fracture problems in cracked solids is presented. The method is discussed in the context of a 3-D finite element analysis. The J integral consists of two parts: the volume integral of the crack front potential over a torus enclosing the crack front and the crack surface integral due to the crack front potential plus the crack face loading. In mixed mode crack problems the total J integral is split into J sub I, J sub II, and J sub III representing the severity of the crack front in three modes of deformations. The direct and decomposition methods are used to separate the modes. These two methods were applied to several mixed mode fracture problems, were analyzed, and results were found to agree well with those available in the literature. The method lends itself to be used as a post-processing subroutine in a general purpose finite element program.

An equivalent domain integral method for three-dimensional mixed-mode fracture problems

NASA Technical Reports Server (NTRS)

Shivakumar, K. N.; Raju, I. S.

1992-01-01

A general formulation of the equivalent domain integral (EDI) method for mixed mode fracture problems in cracked solids is presented. The method is discussed in the context of a 3-D finite element analysis. The J integral consists of two parts: the volume integral of the crack front potential over a torus enclosing the crack front and the crack surface integral due to the crack front potential plus the crack face loading. In mixed mode crack problems the total J integral is split into J sub I, J sub II, and J sub III representing the severity of the crack front in three modes of deformations. The direct and decomposition methods are used to separate the modes. These two methods were applied to several mixed mode fracture problems, were analyzed, and results were found to agree well with those available in the literature. The method lends itself to be used as a post-processing subroutine in a general purpose finite element program.

Modeling of the Electric Characteristics of Solar Cells

NASA Astrophysics Data System (ADS)

Logan, Benjamin; Tzolov, Marian

The purpose of a solar cell is to covert solar energy, through means of photovoltaic action, into a sustainable electrical current that produces usable electricity. The electrical characteristics of solar cells can be modeled to better understand how they function. As an electrical device, solar cells can be conveniently represented as an equivalent electrical circuit with an ideal diode, ideal current source for the photovoltaic action, a shunt resistor for recombination, a resistor in series to account for contact resistance, and a resistor modeling external power consumption. The values of these elements have been modified to model dark and illumination states. Fitting the model to the experimental current voltage characteristics allows to determine the values of the equivalent circuit elements. Comparing values of open circuit voltage, short circuit current, and shunt resistor can determine factors such as the amount of recombination to diagnose problems in solar cells. The many measurable quantities of a solar cell's characteristics give guidance for the design when they are related with microscopic processes.

Linear and nonlinear dynamic analysis of redundant load path bearingless rotor systems

NASA Technical Reports Server (NTRS)

Murthy, V. R.

1985-01-01

The bearingless rotorcraft offers reduced weight, less complexity and superior flying qualities. Almost all the current industrial structural dynamic programs of conventional rotors which consist of single load path rotor blades employ the transfer matrix method to determine natural vibration characteristics because this method is ideally suited for one dimensional chain like structures. This method is extended to multiple load path rotor blades without resorting to an equivalent single load path approximation. Unlike the conventional blades, it isk necessary to introduce the axial-degree-of-freedom into the solution process to account for the differential axial displacements in the different load paths. With the present extension, the current rotor dynamic programs can be modified with relative ease to account for the multiple load paths without resorting to the equivalent single load path modeling. The results obtained by the transfer matrix method are validated by comparing with the finite element solutions. A differential stiffness matrix due to blade rotation is derived to facilitate the finite element solutions.

Using inductively coupled plasma-mass spectrometry for calibration transfer between environmental CRMs.

PubMed

Turk, G C; Yu, L L; Salit, M L; Guthrie, W F

2001-06-01

Multielement analyses of environmental reference materials have been performed using existing certified reference materials (CRMs) as calibration standards for inductively coupled plasma-mass spectrometry. The analyses have been performed using a high-performance methodology that results in comparison measurement uncertainties that are significantly less than the uncertainties of the certified values of the calibration CRM. Consequently, the determined values have uncertainties that are very nearly equivalent to the uncertainties of the calibration CRM. Several uses of this calibration transfer are proposed, including, re-certification measurements of replacement CRMs, establishing traceability of one CRM to another, and demonstrating the equivalence of two CRMs. RM 8704, a river sediment, was analyzed using SRM 2704, Buffalo River Sediment, as the calibration standard. SRM 1632c, Trace Elements in Bituminous Coal, which is a replacement for SRM 1632b, was analyzed using SRM 1632b as the standard. SRM 1635, Trace Elements in Subbituminous Coal, was also analyzed using SRM 1632b as the standard.

Residual stress analysis for oxide thin film deposition on flexible substrate using finite element method

NASA Astrophysics Data System (ADS)

Chen, Hsi-Chao; Huang, Chen-Yu; Lin, Ssu-Fan; Chen, Sheng-Hui

2011-09-01

Residual or internal stresses directly affect a variety of phenomena including adhesion, generation of crystalline defects, perfection of epitaxial layers and formation of film surface growths such as hillocks and whiskers. Sputtering oxide films with high density promote high compressive stress, and it offers researchers a reference if the value of residual stress could be analyzed directly. Since, the study of residual stress of SiO2 and Nb2O5 thin film deposited by DC magnetron sputtered on hard substrate (BK7) and flexible substrate (PET and PC). A finite element method (FEM) with an equivalent-reference-temperature (ERT) technique had been proposed and used to model and evaluate the intrinsic strains of layered structures. The research has improved the equivalent reference temperature (ERT) technique of the simulation of intrinsic strain for oxygen film. The results have also generalized two models connecting to the lattice volume to predict the residual stress of hard substrate and flexible substrate with error of 3% and 6%, respectively.

Analytical Model-Based Design Optimization of a Transverse Flux Machine

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

Hasan, Iftekhar; Husain, Tausif; Sozer, Yilmaz

This paper proposes an analytical machine design tool using magnetic equivalent circuit (MEC)-based particle swarm optimization (PSO) for a double-sided, flux-concentrating transverse flux machine (TFM). The magnetic equivalent circuit method is applied to analytically establish the relationship between the design objective and the input variables of prospective TFM designs. This is computationally less intensive and more time efficient than finite element solvers. A PSO algorithm is then used to design a machine with the highest torque density within the specified power range along with some geometric design constraints. The stator pole length, magnet length, and rotor thickness are the variablesmore » that define the optimization search space. Finite element analysis (FEA) was carried out to verify the performance of the MEC-PSO optimized machine. The proposed analytical design tool helps save computation time by at least 50% when compared to commercial FEA-based optimization programs, with results found to be in agreement with less than 5% error.« less

DNS of turbulent premixed slot flames with mixture inhomogeneity: a study of NOx formation

NASA Astrophysics Data System (ADS)

Luca, Stefano; Attili, Antonio; Bisetti, Fabrizio

2016-11-01

A set of Direct Numerical Simulations of three-dimensional methane/air lean flames in a spatially developing turbulent slot burner are performed. The flames are in the thin-reaction zone regimes and the jet Reynolds number is 5600. This configuration is of interest since it displays turbulent production by mean shear as in real devices. The gas phase hydrodynamics are modeled with the reactive, unsteady Navier-Stokes equations in the low Mach number limit. Combustion is treated with finite-rate chemistry. The jet is characterized by a non-uniform equivalence ratio at the inlet and varying levels of incomplete premixing for the methane/air mixture are considered. The global equivalence ratio is 0.7 and temperature is 800 K. All simulations are performed at 4 atm. The instantaneous profiles of the mass fractions of methane and air at the inlet are sampled from a set of turbulent channel simulations that provide realistic, fully turbulent fields. The data are analyzed to study the influence of partial premixing on the flame structure. Particular focus is devoted to the assessment of heat release rate fluctuations and NOx formation. In particular, the effects of partial premixing on the production rates for the various pathways to NOx formation are investigated.

Use of partial AUC to demonstrate bioequivalence of Zolpidem Tartrate Extended Release formulations.

PubMed

Lionberger, Robert A; Raw, Andre S; Kim, Stephanie H; Zhang, Xinyuan; Yu, Lawrence X

2012-04-01

FDA's bioequivalence recommendation for Zolpidem Tartrate Extended Release Tablets is the first to use partial AUC (pAUC) metrics for determining bioequivalence of modified-release dosage forms. Modeling and simulation studies were performed to aid in understanding the need for pAUC measures and also the proper pAUC truncation times. Deconvolution techniques, In Vitro/In Vivo Correlations, and the CAT (Compartmental Absorption and Transit) model were used to predict the PK profiles for zolpidem. Models were validated using in-house data submitted to the FDA. Using dissolution profiles expressed by the Weibull model as input for the CAT model, dissolution spaces were derived for simulated test formulations. The AUC(0-1.5) parameter was indicative of IR characteristics of early exposure and effectively distinguished among formulations that produced different pharmacodynamic effects. The AUC(1.5-t) parameter ensured equivalence with respect to the sustained release phase of Ambien CR. The variability of AUC(0-1.5) is higher than other PK parameters, but is reasonable for use in an equivalence test. In addition to the traditional PK parameters of AUCinf and Cmax, AUC(0-1.5) and AUC(1.5-t) are recommended to provide bioequivalence measures with respect to label indications for Ambien CR: onset of sleep and sleep maintenance.

Design and simulation of optoelectronic complementary dual neural elements for realizing a family of normalized vector 'equivalence-nonequivalence' operations

NASA Astrophysics Data System (ADS)

Krasilenko, Vladimir G.; Nikolsky, Aleksandr I.; Lazarev, Alexander A.; Magas, Taras E.

2010-04-01

Equivalence models (EM) advantages of neural networks (NN) are shown in paper. EMs are based on vectormatrix procedures with basic operations of continuous neurologic: normalized vector operations "equivalence", "nonequivalence", "autoequivalence", "autononequivalence". The capacity of NN on the basis of EM and of its modifications, including auto-and heteroassociative memories for 2D images, exceeds in several times quantity of neurons. Such neuroparadigms are very perspective for processing, recognition, storing large size and strongly correlated images. A family of "normalized equivalence-nonequivalence" neuro-fuzzy logic operations on the based of generalized operations fuzzy-negation, t-norm and s-norm is elaborated. A biologically motivated concept and time pulse encoding principles of continuous logic photocurrent reflexions and sample-storage devices with pulse-width photoconverters have allowed us to design generalized structures for realization of the family of normalized linear vector operations "equivalence"-"nonequivalence". Simulation results show, that processing time in such circuits does not exceed units of micro seconds. Circuits are simple, have low supply voltage (1-3 V), low power consumption (milliwatts), low levels of input signals (microwatts), integrated construction, satisfy the problem of interconnections and cascading.

Characterization of low-frequency acoustic wave propagation through a periodic corrugated waveguide

NASA Astrophysics Data System (ADS)

Jiang, Changyong; Huang, Lixi

2018-03-01

In this paper, a periodic corrugated waveguide structure is proposed, and its unit-cell is analyzed by the wave finite element method. In low-frequency range, the unit-cell is treated as an equivalent fluid through a homogenization process, and the equivalent acoustic parameters are obtained, which are validated by finite structure simulations and experiments. The proposed structure is shown to add tortuosity to the waveguide, hence higher equivalent fluid density is achieved, while the system elastic modulus remains unchanged. As a result, the equivalent speed of sound is smaller than normal air. The application of such change of speed of sound is demonstrated in the classic quarter-wavelength resonator based on the corrugated waveguide, which gives a lower resonance frequency with the same side branch length. When the waveguide is filled with porous materials, the added tortuosity enhances the broadband, low-frequency sound absorption by increasing the equivalent mass without bringing in excess damping, the latter being partly responsible for the poor performance of usual porous materials in the low-frequency region. Therefore, the proposed structure provides another dimension for the design and optimization of porous sound absorption materials.

MEASUREMENT EQUIVALENCE OF NEIGHBORHOOD QUALITY MEASURES FOR EUROPEAN AMERICAN AND MEXICAN AMERICAN FAMILIES

PubMed Central

Kim, Su Yeong; Nair, Rajni; Knight, George P.; Roosa, Mark W.; Updegraff, Kimberly A.

2009-01-01

The factorial and construct equivalence of subscales assessing parents’ and children’s perceptions of the quality of their neighborhood was examined in Mexican American and European American families. All subscales (dangerous people in the neighborhood, sense of safety in the neighborhood, quality of the physical environment) demonstrated adequate partial factorial invariance across English- and Spanish-speaking Mexican American and European American families. Reports by children about dangerous people in the neighborhood was the closest to achieving strict factorial invariance, and the only one of the four dimensions to achieve invariance in the validity analyses across Mexican American and European American families. The implications of using these self-report neighborhood quality measures in studies of multiple cultural or language groups are discussed. PMID:19183709

Lu-Hf AND Sm-Nd EVOLUTION IN LUNAR MARE BASALTS.

USGS Publications Warehouse

Unruh, D.M.; Stille, P.; Patchett, P.J.; Tatsumoto, M.

1984-01-01

Lu-Hf and Sm-Nd data for mare basalts combined with Rb-Sr and total REE data taken from the literature suggest that the mare basalts were derived by small ( less than equivalent to 10%) degrees of partial melting of cumulate sources, but that the magma ocean from which these sources formed was light REE and hf-enriched. Calculated source compositions range from lherzolite to olivine websterite. Nonmodal melting of small amounts of ilmenite ( less than equivalent to 3%) in the sources seems to be required by the Lu/Hf data. A comparison of the Hf and Nd isotopic characteristics between the mare basalts and terrestrial oceanic basalts reveals that the epsilon Hf/ epsilon Nd ratios in low-Ti mare basalts are much higher than in terrestrial ocean basalts.

The Strengths and Difficulties Questionnaire (SDQ): Factor Structure and Gender Equivalence in Norwegian Adolescents.

PubMed

Bøe, Tormod; Hysing, Mari; Skogen, Jens Christoffer; Breivik, Kyrre

2016-01-01

Although frequently used with older adolescents, few studies of the factor structure, internal consistency and gender equivalence of the SDQ exists for this age group, with inconsistent findings. In the present study, confirmatory factor analysis (CFA) was used to evaluate the five-factor structure of the SDQ in a population sample of 10,254 16-18 year-olds from the youth@hordaland study. Measurement invariance across gender was assessed using multigroup CFA. A modestly modified five-factor solution fitted the data acceptably, accounting for one cross loading and some local dependencies. Importantly, partial measurement non-invariance was identified, with differential item functioning in eight items, and higher correlations between emotional and conduct problems for boys compared to girls. Implications for use clinically and in research are discussed.

Delay Choice vs. Delay Maintenance: Different Measures of Delayed Gratification in Capuchin Monkeys (Cebus apella)

PubMed Central

Addessi, Elsa; Paglieri, Fabio; Beran, Michael J.; Evans, Theodore A.; Macchitella, Luigi; De Petrillo, Francesca; Focaroli, Valentina

2013-01-01

Delaying gratification involves two components: (i) delay choice (selecting a delayed reward over an immediate one), and (ii) delay maintenance (sustaining the decision to delay gratification even if the immediate reward is available during the delay). In primates, two tasks most commonly have explored these components, the Intertemporal choice task and the Accumulation task. It is unclear whether these tasks provide equivalent measures of delay of gratification. Here, we compared the performance of the same capuchin monkeys, belonging to two study populations, between these tasks. We found only limited evidence of a significant correlation in performance. Consequently, in contrast to what is often assumed, our data provide only partial support to the hypothesis that these tasks provide equivalent measures of delay of gratification. PMID:23544770

Multidimensional flamelet-generated manifolds for partially premixed combustion

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

Nguyen, Phuc-Danh; Vervisch, Luc; Subramanian, Vallinayagam

2010-01-15

Flamelet-generated manifolds have been restricted so far to premixed or diffusion flame archetypes, even though the resulting tables have been applied to nonpremixed and partially premixed flame simulations. By using a projection of the full set of mass conservation species balance equations into a restricted subset of the composition space, unsteady multidimensional flamelet governing equations are derived from first principles, under given hypotheses. During the projection, as in usual one-dimensional flamelets, the tangential strain rate of scalar isosurfaces is expressed in the form of the scalar dissipation rates of the control parameters of the multidimensional flamelet-generated manifold (MFM), which ismore » tested in its five-dimensional form for partially premixed combustion, with two composition space directions and three scalar dissipation rates. It is shown that strain-rate-induced effects can hardly be fully neglected in chemistry tabulation of partially premixed combustion, because of fluxes across iso-equivalence-ratio and iso-progress-of-reaction surfaces. This is illustrated by comparing the 5D flamelet-generated manifold with one-dimensional premixed flame and unsteady strained diffusion flame composition space trajectories. The formal links between the asymptotic behavior of MFM and stratified flame, weakly varying partially premixed front, triple-flame, premixed and nonpremixed edge flames are also evidenced. (author)« less

Implications of the licensure of a partially efficacious malaria vaccine on evaluating second-generation vaccines.

PubMed

Fowkes, Freya J I; Simpson, Julie A; Beeson, James G

2013-10-30

Malaria is a leading cause of morbidity and mortality, with approximately 225 million clinical episodes and >1.2 million deaths annually attributed to malaria. Development of a highly efficacious malaria vaccine will offer unparalleled possibilities for disease prevention and remains a key priority for long-term malaria control and elimination. The Malaria Vaccine Technology Roadmap's goal is to 'develop and license a first-generation malaria vaccine that has protective efficacy of more than 50%'. To date, malaria vaccine candidates have only been shown to be partially efficacious (approximately 30% to 60%). However, licensure of a partially effective vaccine will create a number of challenges for the development and progression of new, potentially more efficacious, malaria vaccines in the future. In this opinion piece we discuss the methodological, logistical and ethical issues that may impact on the feasibility and implementation of superiority, non-inferiority and equivalence trials to assess second generation malaria vaccines in the advent of the licensure of a partially efficacious malaria vaccine. Selecting which new malaria vaccines go forward, and defining appropriate methodology for assessment in logistically challenging clinical trials, is crucial. It is imperative that the scientific community considers all the issues and starts planning how second-generation malaria vaccines will advance in the advent of licensure of a partially effective vaccine.

Structure and energetics of extended defects in ice Ih

NASA Astrophysics Data System (ADS)

Silva Junior, Domingos L.; de Koning, Maurice

2012-01-01

We consider the molecular structure and energetics of extended defects in proton-disordered hexagonal ice Ih. Using plane-wave density functional theory (DFT) calculations, we compute the energetics of stacking faults and determine the structure of the 30∘ and 90∘ partial dislocations on the basal plane. Consistent with experimental data, the formation energies of all fully reconstructed stacking faults are found to be very low. This is consistent with the idea that basal-plane glide dislocations in ice Ih are dissociated into partial dislocations separated by an area of stacking fault. For both types of partial dislocation we find a strong tendency toward core reconstruction through pairwise hydrogen-bond reformation. In the case of the 30∘ dislocation, the pairwise hydrogen-bond formation leads to a period-doubling core structure equivalent to that seen in zinc-blende semiconductor crystals. For the 90∘ partial we consider two possible core reconstructions, one in which the periodicity of the structure along the core remains unaltered and another in which it is doubled. The latter is preferred, although the energy difference between both is rather small, so that a coexistence of both reconstructions appears plausible. Our results imply that a mobility theory for dislocations on the basal plane in ice Ih should be based on the idea of reconstructed partial dislocations.

Structure formation in grade 20 steel during equal-channel angular pressing and subsequent heating

NASA Astrophysics Data System (ADS)

Dobatkin, S. V.; Odesskii, P. D.; Raab, G. I.; Tyutin, M. R.; Rybalchenko, O. V.

2016-11-01

The structure formation and the mechanical properties of quenched and tempered grade 20 steel after equal-channel angular pressing (ECAP) at various true strains and 400°C are studied. Electron microscopy analysis after ECAP shows a partially submicrocrystalline and partially subgrain structure with a structural element size of 340-375 nm. The structural element size depends on the region in which the elements are formed (polyhedral ferrite, needle-shaped ferrite, tempered martensite, and pearlite). Heating of the steel after ECAP at 400 and 450°C increases the fraction of high-angle boundaries and the structural ferrite element size to 360-450 nm. The fragmentation and spheroidization of cementite lamellae of pearlite and subgrain coalescence in the regions of needle-shaped ferrite and tempered martensite take place at a high ECAP true strain and heating temperature. Structural refinement ensures considerable strengthening, namely, UTS 742-871 MPa at EL 11-15.3%. The strength slightly increases, whereas the plasticity slightly decreases when the true strain increases during ECAP. After ECAP and heating, the strength and plastic properties of the grade 20 steel remain almost the same.

Optimal moving grids for time-dependent partial differential equations

NASA Technical Reports Server (NTRS)

Wathen, A. J.

1992-01-01

Various adaptive moving grid techniques for the numerical solution of time-dependent partial differential equations were proposed. The precise criterion for grid motion varies, but most techniques will attempt to give grids on which the solution of the partial differential equation can be well represented. Moving grids are investigated on which the solutions of the linear heat conduction and viscous Burgers' equation in one space dimension are optimally approximated. Precisely, the results of numerical calculations of optimal moving grids for piecewise linear finite element approximation of PDE solutions in the least-squares norm are reported.

Effects of task-irrelevant grouping on visual selection in partial report.

PubMed

Lunau, Rasmus; Habekost, Thomas

2017-07-01

Perceptual grouping modulates performance in attention tasks such as partial report and change detection. Specifically, grouping of search items according to a task-relevant feature improves the efficiency of visual selection. However, the role of task-irrelevant feature grouping is not clearly understood. In the present study, we investigated whether grouping of targets by a task-irrelevant feature influences performance in a partial-report task. In this task, participants must report as many target letters as possible from a briefly presented circular display. The crucial manipulation concerned the color of the elements in these trials. In the sorted-color condition, the color of the display elements was arranged according to the selection criterion, and in the unsorted-color condition, colors were randomly assigned. The distractor cost was inferred by subtracting performance in partial-report trials from performance in a control condition that had no distractors in the display. Across five experiments, we manipulated trial order, selection criterion, and exposure duration, and found that attentional selectivity was improved in sorted-color trials when the exposure duration was 200 ms and the selection criterion was luminance. This effect was accompanied by impaired selectivity in unsorted-color trials. Overall, the results suggest that the benefit of task-irrelevant color grouping of targets is contingent on the processing locus of the selection criterion.

Preparation and characterization of ceramic sensors for use at elevated temperatures

NASA Astrophysics Data System (ADS)

You, Tao

Ceramic ITO strain sensors were prepared by reactive sputtering in various nitrogen/oxygen/argon partial pressures. The thickness of the active ITO strain elements played a significant role in the high temperature stability and piezoresistive properties, specifically, these results indicated that both gauge factor and drift rate were affected by the thickness of ITO films comprising the active strain elements. The influence of nitrogen in the reactive sputtered ITO films on the microstructure and the high temperature piezoresistive properties was also investigated. Scanning electron microscopy (SEM) revealed a partially sintered microstructure consisting of a contiguous network of sub-micron ITO particles with well-defined necks and isolated nanoporosity. Sintering and densification of the ITO particles containing these nitrogen rich grain boundaries was retarded and a contiguous network of nano-sized ITO particles was established. Aluminum doped indium tin oxide thin film exhibited an enhanced high temperature stability compared with undoped ITO thin film. The effect of aluminum doped ITO was investigated under various preparation and testing environments. Electron spectroscopy for chemical analysis (ESCA) studies indicated that interfacial reactions between ITO and aluminum increased the stability of ITO at elevated temperatures. These binding energies of indium-indium are significantly higher than those associated with stoichiometric indium oxide. A robust ceramic temperature sensor was fabricated by two different ITO elements, each with substantially different charge carrier concentrations. Thermal cycling of ITO thin films in a varied of partial oxygen pressures conditions showed that temperature coefficient of resistance (TCR) was nearly independent of oxygen partial pressure. A thermoelectric power of 6.0muV/°C and a linear voltage-temperature response were measured for an ITO thin film ceramic thermocouple over the temperature range 25--1250°C.

EQUIVALENCE OF ELEMENTAL CARBON BY THERMAL/OPTICAL REFLECTANCE AND TRANSMITTANCE WITH DIFFERENT TEMPERATURE PROTOCOLS. (R831086)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

14 CFR 125.213 - Miscellaneous equipment.

Code of Federal Regulations, 2012 CFR

2012-01-01

... provided for transferring an instrument from its primary operating system to an alternative system, the...) A windshield wiper or equivalent for each pilot station. (c) A power supply and distribution system... distribution system fails. The use of common elements in the system may be approved if the Administrator finds...

14 CFR 125.213 - Miscellaneous equipment.

Code of Federal Regulations, 2010 CFR

2010-01-01

... provided for transferring an instrument from its primary operating system to an alternative system, the...) A windshield wiper or equivalent for each pilot station. (c) A power supply and distribution system... distribution system fails. The use of common elements in the system may be approved if the Administrator finds...

14 CFR 125.213 - Miscellaneous equipment.

Code of Federal Regulations, 2011 CFR

2011-01-01

... provided for transferring an instrument from its primary operating system to an alternative system, the...) A windshield wiper or equivalent for each pilot station. (c) A power supply and distribution system... distribution system fails. The use of common elements in the system may be approved if the Administrator finds...

14 CFR 125.213 - Miscellaneous equipment.

Code of Federal Regulations, 2013 CFR

2013-01-01

... provided for transferring an instrument from its primary operating system to an alternative system, the...) A windshield wiper or equivalent for each pilot station. (c) A power supply and distribution system... distribution system fails. The use of common elements in the system may be approved if the Administrator finds...

14 CFR 125.213 - Miscellaneous equipment.

Code of Federal Regulations, 2014 CFR

2014-01-01

... provided for transferring an instrument from its primary operating system to an alternative system, the...) A windshield wiper or equivalent for each pilot station. (c) A power supply and distribution system... distribution system fails. The use of common elements in the system may be approved if the Administrator finds...

28 CFR 36.607 - Effect of certification.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PUBLIC ACCOMMODATIONS AND IN COMMERCIAL FACILITIES Certification of State Laws or Local Building Codes... the question of whether equipment in a building built according to the code satisfies the Act's... equivalency only with respect to those features or elements that are both covered by the certified code and...

Role of geomechanically grown fractures on dispersive transport in heterogeneous geological formations.

PubMed

Nick, H M; Paluszny, A; Blunt, M J; Matthai, S K

2011-11-01

A second order in space accurate implicit scheme for time-dependent advection-dispersion equations and a discrete fracture propagation model are employed to model solute transport in porous media. We study the impact of the fractures on mass transport and dispersion. To model flow and transport, pressure and transport equations are integrated using a finite-element, node-centered finite-volume approach. Fracture geometries are incrementally developed from a random distributions of material flaws using an adoptive geomechanical finite-element model that also produces fracture aperture distributions. This quasistatic propagation assumes a linear elastic rock matrix, and crack propagation is governed by a subcritical crack growth failure criterion. Fracture propagation, intersection, and closure are handled geometrically. The flow and transport simulations are separately conducted for a range of fracture densities that are generated by the geomechanical finite-element model. These computations show that the most influential parameters for solute transport in fractured porous media are as follows: fracture density and fracture-matrix flux ratio that is influenced by matrix permeability. Using an equivalent fracture aperture size, computed on the basis of equivalent permeability of the system, we also obtain an acceptable prediction of the macrodispersion of poorly interconnected fracture networks. The results hold for fractures at relatively low density.

Analysis of temperature influence on the informative parameters of single-coil eddy current sensors

NASA Astrophysics Data System (ADS)

Borovik, S. Yu.; Kuteynikova, M. M.; Sekisov, Yu. N.; Skobelev, O. P.

2017-07-01

This paper describes the study of temperature in the flowing part of a turbine on the informative parameters (equivalent inductances of primary windings of matching transformers) of single-coil eddy-current sensors with a sensitive element in the form of a conductor section, which are used as part of automation systems for testing gas-turbine engines. In this case, the objects of temperature influences are both sensors and controlled turbine blades. The existing model of electromagnetic interaction of a sensitive element with the end part of a controlled blade is used to obtain quantitative estimates of temperature changes of equivalent inductances of sensitive elements and primary windings of matching transformers. This model is also used to determine the corresponding changes of the informative parameter of the sensor in the process of experimental studies of temperature influences on it (in the absence of blades in the sensitive region). This paper also presents transformations in the form of relationships of informative parameters with radial and axial displacements at normal (20 °C) and nominal (1000 °C) temperatures, and their difference is used to determine the families of dominant functions of temperature, which characterize possible temperature errors for any radial and axial displacements in the ranges of their variation.

Effect of Chemical Composition on Susceptibility to Weld Solidification Cracking in Austenitic Weld Metal

NASA Astrophysics Data System (ADS)

Kadoi, Kota; Shinozaki, Kenji

2017-12-01

The influence of the chemical composition, especially the niobium content, chromium equivalent Creq, and nickel equivalent Nieq, on the weld solidification cracking susceptibility in the austenite single-phase region in the Schaeffler diagram was investigated. Specimens were fabricated using the hot-wire laser welding process with widely different compositions of Creq, Nieq, and niobium in the region. The distributions of the susceptibility, such as the crack length and brittle temperature range (BTR), in the Schaeffler diagram revealed a region with high susceptibility to solidification cracking. Addition of niobium enhanced the susceptibility and changed the distribution of the susceptibility in the diagram. The BTR distribution was in good agreement with the distribution of the temperature range of solidification (Δ T) calculated by solidification simulation based on Scheil model. Δ T increased with increasing content of alloying elements such as niobium. The distribution of Δ T was dependent on the type of alloying element owing to the change of the partitioning behavior. Thus, the solidification cracking susceptibility in the austenite single-phase region depends on whether the alloy contains elements. The distribution of the susceptibility in the region is controlled by the change in Δ T and the segregation behavior of niobium with the chemical composition.

Finite element stress analysis of stainless steel crowns.

PubMed

Prabhakar, Attiguppe R; Yavagal, Chandrashekar M; Chakraborty, Amrita; Sugandhan, S

2015-01-01

Though stainless steel crowns (SSCs) have often been stated as the best restorative modality, there are limited studies demonstrating its efficacy in restoring the functional integrity of the primary dentition. Hence has arisen, the necessity to establish the supremacy of SSCs. Evaluation of the efficacy of SSC to with stand compressive (0°), shearing (90°), and torsional (45°) stress when used as a restorative material. The study design employed four finite element models, each with differing amounts of tooth structure, which were exported to ANSYS software and subjected to an average simulated bite force of 245N. Four maxillary deciduous primary molars restored with SSCs (3M ESPE) were subjected to spiral computed tomography (CT) in order to obtain three-dimensional (3D) images, which were then converted into finite element models. They were each subjected to forces along the long axis of the tooth and at 45°and 90°. The maximal equivalent von Mises stress was demonstrated in the SSCs of all the models with only a minimal amount observed in the underlying dentine. In all situations, the maximal equivalent von Mises stress was well below the ultimate tensile strength values of stainless steel and dentine. Even at maximal physiologic masticatory force levels, a grossly destructed tooth restored with SSC is able to resist deformation.

Acute and chronic response of meniscal fibrocartilage to holmium:YAG laser irradiation

NASA Astrophysics Data System (ADS)

Horan, Patrick J.; Popovic, Neven A.; Islinger, Richard B.; Kuklo, Timothy R.; Dick, Edward J.

1997-05-01

The acute and chronic (10 week) histological effects of the holmium:YAG laser during partial meniscectomy in an in vivo rabbit model were investigated. Twenty-four adult male New Zealand rabbits underwent bilateral parapatellar medial knee arthrotomies. In the right knee, a partial medial meniscectomy was done through the avascular zone using a standard surgical blade. In the left knee, an anatomically similar partial medial meniscectomy was performed using a Ho:YAG laser (Coherent, USA). This study indicates that the laser creates two zones of damage in the meniscal fibrocartilage and that the zone of thermal change may act as a barrier to healing. The zone of thermal change which is eventually debrided was thought at the time of surgery to be viable. In the laser cut menisci, the synovium appears to have greater inflammation early and to be equivalent with the scalpel cut after three weeks. At all time periods there appeared more cellular damage in the laser specimens.

Effects of a meaningful, a discriminative, and a meaningless stimulus on equivalence class formation.

PubMed

Fields, Lanny; Arntzen, Erik; Nartey, Richard K; Eilifsen, Christoffer

2012-03-01

Thirty college students attempted to form three 3-node 5-member equivalence classes under the simultaneous protocol. After concurrent training of AB, BC, CD, and DE relations, all probes used to assess the emergence of symmetrical, transitive, and equivalence relations were presented for two test blocks. When the A-E stimuli were all abstract shapes, none of 10 participants formed classes. When the A, B, D, and E stimuli were abstract shapes and the C stimuli were meaningful pictures, 8 of 10 participants formed classes. This high yield may reflect the expansion of existing classes that consist of the associates of the meaningful stimuli, rather than the formation of the ABCDE classes, per se. When the A-E stimuli were abstract shapes and the C stimuli became S(D)s prior to class formation, 5 out of 10 participants formed classes. Thus, the discriminative functions served by the meaningful stimuli can account for some of the enhancement of class formation produced by the inclusion of a meaningful stimulus as a class member. A sorting task, which provided a secondary measure of class formation, indicated the formation of all three classes when the emergent relations probes indicated the same outcome. In contrast, the sorting test indicated "partial" class formation when the emergent relations test indicated no class formation. Finally, the effects of nodal distance on the relatedness of stimuli in the equivalence classes were not influenced by the functions served by the C stimuli in the equivalence classes.

Correlates of residual fatigue in patients with major depressive disorder: The role of psychotropic medication.

PubMed

Chung, Ka-Fai; Yu, Yee-Man; Yeung, Wing-Fai

2015-11-01

Fatigue is not only a core symptom of major depressive disorder (MDD), but also a common residual symptom. We determined the sociodemographic, clinical, and pharmacologic factors that were associated with fatigue in patients with remission or partial remission of MDD. Data was derived from a randomized controlled trial of acupuncture in 137 MDD patients with residual symptoms. Fatigue was measured by Multidimensional Fatigue Inventory (MFI-20). Self-report and clinician-rated scales were used to assess psychopathology. 17-item Hamilton Depression Rating Scale (HDRS17) score≤7 denoted MDD remission. Participants' average HDRS17 score was 10.5; 29.2% were in remission. The average MFI-20 score was 71.8; 83.2% had severe fatigue, defined as MFI-20 score≥60. Fifty-two of 137 participants (38%) were using sedating psychotropic medications. Antidepressant dosage ranged from 1-90mg fluoxetine equivalent and sedatives/hypnotics from 1-60mg diazepam equivalent. There were significant correlations between MFI-20 score and HDRS17 depression and anxiety subscores, Hospital Anxiety and Depression Scale (HADS) depression and anxiety subscores, and Pain Catastrophizing Scale score, but insomnia and daytime sleepiness, sociodemographics, current medical conditions, and psychotropic medication use were not significant correlates. Upon multiple regression, HADS and HDRS17 depression scores independently predicted MFI-20 score. In remission and partial remission subgroups, HADS depression score was an independent predictor. Participants were recruited from specialty psychiatric units; hence the findings may not be applicable in non-specialized settings. Fatigue was predicted by depression severity in remitted or partially remitted MDD. Psychotropic medication and higher dosage were not associated with greater fatigue. Copyright © 2015 Elsevier B.V. All rights reserved.

Finite element stress, vibration, and buckling analysis of laminated beams with the use of refined elements

NASA Astrophysics Data System (ADS)

Borovkov, Alexei I.; Avdeev, Ilya V.; Artemyev, A.

1999-05-01

In present work, the stress, vibration and buckling finite element analysis of laminated beams is performed. Review of the equivalent single-layer (ESL) laminate theories is done. Finite element algorithms and procedures integrated into the original FEA program system and based on the classical laminated plate theory (CLPT), first-order shear deformation theory (FSDT), third-order theory of Reddy (TSDT-R) and third- order theory of Kant (TSDT-K) with the use of the Lanczos method for solving of the eigenproblem are developed. Several numerical tests and examples of bending, free vibration and buckling of multilayered and sandwich beams with various material, geometry properties and boundary conditions are solved. New effective higher-order hierarchical element for the accurate calculation of transverse shear stress is proposed. The comparative analysis of results obtained by the considered models and solutions of 2D problems of the heterogeneous anisotropic elasticity is fulfilled.

Electrical and mechanical fully coupled theory and experimental verification of Rosen-type piezoelectric transformers.

PubMed

Hsu, Yu-Hsiang; Lee, Chih-Kung; Hsiao, Wen-Hsin

2005-10-01

A piezoelectric transformer is a power transfer device that converts its input and output voltage as well as current by effectively using electrical and mechanical coupling effects of piezoelectric materials. Equivalent-circuit models, which are traditionally used to analyze piezoelectric transformers, merge each mechanical resonance effect into a series of ordinary differential equations. Because of using ordinary differential equations, equivalent circuit models are insufficient to reflect the mechanical behavior of piezoelectric plates. Electromechanically, fully coupled governing equations of Rosen-type piezoelectric transformers, which are partial differential equations in nature, can be derived to address the deficiencies of the equivalent circuit models. It can be shown that the modal actuator concept can be adopted to optimize the electromechanical coupling effect of the driving section once the added spatial domain design parameters are taken into account, which are three-dimensional spatial dependencies of electromechanical properties. The maximum power transfer condition for a Rosen-type piezoelectric transformer is detailed. Experimental results, which lead us to a series of new design rules, also are presented to prove the validity and effectiveness of the theoretical predictions.

Equivalent Relaxations of Optimal Power Flow

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

Bose, S; Low, SH; Teeraratkul, T

2015-03-01

Several convex relaxations of the optimal power flow (OPF) problem have recently been developed using both bus injection models and branch flow models. In this paper, we prove relations among three convex relaxations: a semidefinite relaxation that computes a full matrix, a chordal relaxation based on a chordal extension of the network graph, and a second-order cone relaxation that computes the smallest partial matrix. We prove a bijection between the feasible sets of the OPF in the bus injection model and the branch flow model, establishing the equivalence of these two models and their second-order cone relaxations. Our results implymore » that, for radial networks, all these relaxations are equivalent and one should always solve the second-order cone relaxation. For mesh networks, the semidefinite relaxation and the chordal relaxation are equally tight and both are strictly tighter than the second-order cone relaxation. Therefore, for mesh networks, one should either solve the chordal relaxation or the SOCP relaxation, trading off tightness and the required computational effort. Simulations are used to illustrate these results.« less

Autoclave decomposition method for metals in soils and sediments.

PubMed

Navarrete-López, M; Jonathan, M P; Rodríguez-Espinosa, P F; Salgado-Galeana, J A

2012-04-01

Leaching of partially leached metals (Fe, Mn, Cd, Co, Cu, Ni, Pb, and Zn) was done using autoclave technique which was modified based on EPA 3051A digestion technique. The autoclave method was developed as an alternative to the regular digestion procedure passed the safety norms for partial extraction of metals in polytetrafluoroethylene (PFA vessel) with a low constant temperature (119.5° ± 1.5°C) and the recovery of elements were also precise. The autoclave method was also validated using two Standard Reference Materials (SRMs: Loam Soil B and Loam Soil D) and the recoveries were equally superior to the traditionally established digestion methods. Application of the autoclave was samples from different natural environments (beach, mangrove, river, and city soil) to reproduce the recovery of elements during subsequent analysis.

The Relationship between Litho-Sequential Stratigraphy, Chemostratigraphy of Khuff Carbonates: Implication for Facies and Paleoenvironmental Recognition and Correlation, Central Saudi Arabia

NASA Astrophysics Data System (ADS)

Abdullatif, Osman; Abdlmutalib, Ammar; Ahmed, Jarrah; Abdelgadir, Mohamed; Adam, Ammar

2017-04-01

The Permian-Triassic Khuff Formation carbonate reservoirs (and equivalents) in the Middle East are estimated to contain about 15-20 % of the world's gas reserves. Excellently exposed outcropping Khuff strata in central Saudi Arabia provide good outcrop equivalents to the Khuff Formation in the subsurface. The Khuff Formation is composed of five members and from bottom to top are Ash Shiqqah, Huqayl, Duhaysan, Midnab and Khartam members. The Carbonates lithofacies dominate with minor terrestrial clastics, and the paleoenvironments vary from terrestrial, sabkha, tidal-intertidal and open marine environments. This study investigates the relationship between lithostratigraphy, sequence stratigraphy and chemostratigraphy by integration of both field and laboratory sedimentological and chemical elements data. The vertical chemical elements profiles along the Khuff members show variations in their chemical elements content with the variation in lithofacies types, staking pattern, depositional and stratigraphic pattern. The chemostratigraphic distribution of the chemical elements also showed variation within and between the Khuff members. There is a general agreement between chemostratigraphic analyses based on vertical profiles and binary cross plots. The Khuff members and their stratigraphic boundaries can be differentiated based on their chemostratigraphic signatures. Moreover, the lithofacies and depositional paleoenvironmental of different Khuff members can be identified based on their chemical element contents. Chemostratigraphic zones or clusters are markedly established indicating different lithofacies and depositional paleoenvironments. Terrestrial, channel, lacustrine, shoreline to open marine carbonate lithofacies, as building blocks of sequence stratigraphy, all may be distinguished based on their chemical signatures. These outcrop analog results might be of significance to lithofacies, paleoenvironmental, stratigraphic identification, classification and correlation of Khuff Formation in the subsurface. The results might also provide guides and application to reservoir Khuff Formation identification, layering and zonation in the subsurface.

Preliminary study of radioactive limonite localities in Colorado, Utah, and Wyoming

USGS Publications Warehouse

Lovering, T.G.; Beroni, E.P.

1956-01-01

Nine radioactive limonite localities of different types were sampled during the spring and fall of 1953 in an effort to establish criteria for differentiating limonite outcrops associated with uranium or thorium deposits from limonite outcrops not associated with such deposits. The samples were analyzed for uranium and thorium by standard chemical methods, for equivalent uranium by the radiometric method, and for a number of common metals by semiquantitative geochemical methods. Correlation coefficients were then calculated for each of the metals with respect to equivalent uranium, and to uranium where present, for all of the samples from each locality. The correlation coefficients may indicate a significant association between uranium or thorium and certain metals. Occurrences of specific that are interpreted as significant very considerably for different uranium localities but are more consistent for the thorium localities. Samples taken from radioactive outcrops in the vicinity of uranium or thorium deposits can be quickly analyzed by geochemical methods for various elements. Correlation coefficients can then be determined for the various elements with respect to uranium or thorium; if any significant correlations are obtained, the elements showing such correlation may be indicators of uranium or thorium. Soil samples of covered areas in the vicinity of the radioactive outcrop may then be analyzed for the indicator elements and any resulting anomalies used as a guide for prospecting where the depth of overburden is too great to allow the use of radiation-detecting instruments. Correlation coefficients of the associated indicator elements, used in conjunction with petrographic evidence, may also be useful in interpreting the origin and paragenesis of radioactive deposits. Changes in color of limonite stains on the outcrop may also be a useful guide to ore in some areas.

Chromatic Properties of Index of Refraction Gradients in Glass.

NASA Astrophysics Data System (ADS)

Ryan-Howard, Danette Patrice

The chromatic properties of index of refraction gradients have been predicted theoretically and verified experimentally. The use of these materials in the design of color corrected optical systems has been investigated and confirmed by the evaluation of two fabricated lenses. A model for the chromatic properties of gradient index materials has been developed. The index of refraction is calculated based on the composition of the material. Since the index of refraction and the conventional Abbe number change as a function of the composition of the glass, a gradient Abbe number and a partial dispersion are defined. Analysis of combinations of ion exchange pairs and glasses result in a wide range of gradient Abbe numbers and partial dispersions. These ranges can be further extended by using glasses which contain more than one exchange ion or by using mixed salt baths. The chromatic properties were measured with a multiple wavelength A.C. interferometer. The gradient Abbe numbers and partial dispersions for a number of samples were calculated. Evaluation of the samples showed that the index and dispersion data correlated well with that predicted by the model. Thin lens formulae for the paraxial axial color and secondary spectrum of a radial gradient singlet with curves were examined. The design of a single element 10x microscope objective verified the applicability of these formulae. The design of a two element 40x microscope objective showed that a six element diffraction limited 40x objective can be replaced with a two element system composed of one homogeneous lens and one gradient lens without sacrificing either monochromatic performance or color correction. A previously fabricated axial gradient collimator and a fabricated Wood element were evaluated. Correlation of the directly measured quantities, paraxial axial color, secondary spectrum and spherochromatism with the values predicted by the model verified that the predicted superior performance of gradient-index lenses can be obtained.

Hydrous metasomatism of oceanic sub-arc mantle, Lihir, Papua New Guinea. Part 2. Trace element characteristics of slab-derived fluids

NASA Astrophysics Data System (ADS)

Grégoire, Michel; McInnes, Brent I. A.; O'Reilly, Suzanne Y.

2001-11-01

Spinel peridotite xenoliths recovered from the Tubaf and Edison volcanoes, south of Lihir Island in the Tabar-Lihir-Tanga-Feni island arc in Papua New Guinea, are predominantly fresh, refractory harzburgites. Many of the harzburgite xenoliths have cross-cutting vein networks and show evidence of modal metasomatism. These metasomatic veins contain a secondary mineral assemblage consisting of fibrous, radiating orthopyroxene and fine-grained Fe-Ni sulfide with minor olivine, clinopyroxene, phlogopite, amphibole and magnetite. Adjacent to the veins, primary clinopyroxene is cloudy while orthopyroxene exhibits replacement by secondary fibrous orthopyroxene, similar in habit to orthopyroxene occurring in the veins. The mineralogical and geochemical characteristics of the Tubaf mantle xenoliths are the product of two major processes: an early partial melting depletion event that was overprinted by oxidation and alkali enrichment related to percolation of slab-derived, hydrous melts. HREE and MREE concentrations in clinopyroxene from the least metasomatised harzburgites indicate that they are the residues from a 15% to 25% partial melting event, consistent with formation in a MOR setting. The secondary vein assemblages show strong enrichment in the LILE (primarily Sr, Ba, Rb, Th, U and Pb) and the REE (primarily La, Ce, Nd, Sm, Eu and Gd), while the HFSE (Nb, Ta, Zr, Hf, and Ti) are neither enriched nor depleted. The mineral precipitates in the vein assemblages have high LREE/HFSE and LILE/HFSE, and reflect the relative solubility of these elements in hydrous melts. These trace element characteristics are similar to those of the Tabar-Lihir-Tanga-Feni arc lavas, and display the commonly observed HFSE depletion of arc magmatism. These findings support the hypothesis that this so-called "arc signature" is primarily dependent on the relative solubility of elements in slab-derived, hydrous melts, and the enrichment of these soluble elements in metasomatised mantle regions that are prone to preferential partial melting.

Expert system for surveillance and diagnosis of breach fuel elements

DOEpatents

Gross, K.C.

1988-01-21

An apparatus and method are disclosed for surveillance and diagnosis of breached fuel elements in a nuclear reactor. A delayed neutron monitoring system provides output signals indicating the delayed neutron activity and age and the equivalent recoil area of a breached fuel element. Sensors are used to provide outputs indicating the status of each component of the delayed neutron monitoring system. Detectors also generate output signals indicating the reactor power level and the primary coolant flow rate of the reactor. The outputs from the detectors and sensors are interfaced with an artificial intelligence-based knowledge system which implements predetermined logic and generates output signals indicating the operability of the reactor. 2 figs.

Expert system for surveillance and diagnosis of breach fuel elements

DOEpatents

Gross, Kenny C.

1989-01-01

An apparatus and method are disclosed for surveillance and diagnosis of breached fuel elements in a nuclear reactor. A delayed neutron monitoring system provides output signals indicating the delayed neutron activity and age and the equivalent recoil areas of a breached fuel element. Sensors are used to provide outputs indicating the status of each component of the delayed neutron monitoring system. Detectors also generate output signals indicating the reactor power level and the primary coolant flow rate of the reactor. The outputs from the detectors and sensors are interfaced with an artificial intelligence-based knowledge system which implements predetermined logic and generates output signals indicating the operability of the reactor.

False memory for idiomatic expressions in younger and older adults: evidence for indirect activation of figurative meanings

PubMed Central

Coane, Jennifer H.; Sánchez-Gutiérrez, Claudia; Stillman, Chelsea M.; Corriveau, Jennifer A.

2014-01-01

Idiomatic expressions can be interpreted literally or figuratively. These two meanings are often processed in parallel or very rapidly, as evidenced by online measures of idiomatic processing. Because in many cases the figurative meaning cannot be derived from the component lexical elements and because of the speed with which this meaning is accessed, it is assumed such meanings are stored in semantic memory. In the present study, we examined how literal equivalents and intact idiomatic expressions are stored in memory and whether episodic memory traces interact or interfere with semantic-level representations and vice versa. To examine age-invariance, younger and older adults studied lists of idioms and literal equivalents. On a recognition test, some studied items were presented in the alternative form (e.g., if the idiom was studied, its literal equivalent was tested). False alarms to these critical items suggested that studying literal equivalents activates the idiom from which they are derived, presumably due to spreading activation in lexical/semantic networks, and results in high rates of errors. Importantly, however, the converse (false alarms to literal equivalents after studying the idiom) were significantly lower, suggesting an advantage in storage for idioms. The results are consistent with idiom processing models that suggest obligatory access to figurative meanings and that this access can also occur indirectly, through literal equivalents. PMID:25101030

False memory for idiomatic expressions in younger and older adults: evidence for indirect activation of figurative meanings.

PubMed

Coane, Jennifer H; Sánchez-Gutiérrez, Claudia; Stillman, Chelsea M; Corriveau, Jennifer A

2014-01-01

Idiomatic expressions can be interpreted literally or figuratively. These two meanings are often processed in parallel or very rapidly, as evidenced by online measures of idiomatic processing. Because in many cases the figurative meaning cannot be derived from the component lexical elements and because of the speed with which this meaning is accessed, it is assumed such meanings are stored in semantic memory. In the present study, we examined how literal equivalents and intact idiomatic expressions are stored in memory and whether episodic memory traces interact or interfere with semantic-level representations and vice versa. To examine age-invariance, younger and older adults studied lists of idioms and literal equivalents. On a recognition test, some studied items were presented in the alternative form (e.g., if the idiom was studied, its literal equivalent was tested). False alarms to these critical items suggested that studying literal equivalents activates the idiom from which they are derived, presumably due to spreading activation in lexical/semantic networks, and results in high rates of errors. Importantly, however, the converse (false alarms to literal equivalents after studying the idiom) were significantly lower, suggesting an advantage in storage for idioms. The results are consistent with idiom processing models that suggest obligatory access to figurative meanings and that this access can also occur indirectly, through literal equivalents.

A finite element analysis of the stress distribution to the mandible from impact forces with various orientations of third molars*

PubMed Central

Liu, Yun-feng; Wang, Russell; Baur, Dale A.; Jiang, Xian-feng

2018-01-01

Objective: To investigate the stress distribution to the mandible, with and without impacted third molars (IM3s) at various orientations, resulting from a 2000-Newton impact force either from the anterior midline or from the body of the mandible. Materials and methods: A 3D mandibular virtual model from a healthy dentate patient was created and the mechanical properties of the mandible were categorized to 9 levels based on the Hounsfield unit measured from computed tomography (CT) images. Von Mises stress distributions to the mandibular angle and condylar areas from static impact forces (Load I-front blow and Load II left blow) were evaluated using finite element analysis (FEA). Six groups with IM3 were included: full horizontal bony, full vertical bony, full 450 mesioangular bony, partial horizontal bony, partial vertical, and partial 450 mesioangular bony impaction, and a baseline group with no third molars. Results: Von Mises stresses in the condyle and angle areas were higher for partially than for fully impacted third molars under both loading conditions, with partial horizontal IM3 showing the highest fracture risk. Stresses were higher on the contralateral than on the ipsilateral side. Under Load II, the angle area had the highest stress for various orientations of IM3s. The condylar region had the highest stress when IM3s were absent. Conclusions: High-impact forces are more likely to cause condylar rather than angular fracture when IM3s are missing. The risk of mandibular fracture is higher for partially than fully impacted third molars, with the angulation of impaction having little effect on facture risk. PMID:29308606

Comparison of exact solution with Eikonal approximation for elastic heavy ion scattering

NASA Technical Reports Server (NTRS)

Dubey, Rajendra R.; Khandelwal, Govind S.; Cucinotta, Francis A.; Maung, Khin Maung

1995-01-01

A first-order optical potential is used to calculate the total and absorption cross sections for nucleus-nucleus scattering. The differential cross section is calculated by using a partial-wave expansion of the Lippmann-Schwinger equation in momentum space. The results are compared with solutions in the Eikonal approximation for the equivalent potential and with experimental data in the energy range from 25A to 1000A MeV.

A finite element-based algorithm for rubbing induced vibration prediction in rotors

NASA Astrophysics Data System (ADS)

Behzad, Mehdi; Alvandi, Mehdi; Mba, David; Jamali, Jalil

2013-10-01

In this paper, an algorithm is developed for more realistic investigation of rotor-to-stator rubbing vibration, based on finite element theory with unilateral contact and friction conditions. To model the rotor, cross sections are assumed to be radially rigid. A finite element discretization based on traditional beam theories which sufficiently accounts for axial and transversal flexibility of the rotor is used. A general finite element discretization model considering inertial and viscoelastic characteristics of the stator is used for modeling the stator. Therefore, for contact analysis, only the boundary of the stator is discretized. The contact problem is defined as the contact between the circular rigid cross section of the rotor and “nodes” of the stator only. Next, Gap function and contact conditions are described for the contact problem. Two finite element models of the rotor and the stator are coupled via the Lagrange multipliers method in order to obtain the constrained equation of motion. A case study of the partial rubbing is simulated using the algorithm. The synchronous and subsynchronous responses of the partial rubbing are obtained for different rotational speeds. In addition, a sensitivity analysis is carried out with respect to the initial clearance, the stator stiffness, the damping parameter, and the coefficient of friction. There is a good agreement between the result of this research and the experimental result in the literature.

Partial coherence with application to the monotonicity problem of coherence involving skew information

NASA Astrophysics Data System (ADS)

Luo, Shunlong; Sun, Yuan

2017-08-01

Quantifications of coherence are intensively studied in the context of completely decoherent operations (i.e., von Neuamnn measurements, or equivalently, orthonormal bases) in recent years. Here we investigate partial coherence (i.e., coherence in the context of partially decoherent operations such as Lüders measurements). A bona fide measure of partial coherence is introduced. As an application, we address the monotonicity problem of K -coherence (a quantifier for coherence in terms of Wigner-Yanase skew information) [Girolami, Phys. Rev. Lett. 113, 170401 (2014), 10.1103/PhysRevLett.113.170401], which is introduced to realize a measure of coherence as axiomatized by Baumgratz, Cramer, and Plenio [Phys. Rev. Lett. 113, 140401 (2014), 10.1103/PhysRevLett.113.140401]. Since K -coherence fails to meet the necessary requirement of monotonicity under incoherent operations, it is desirable to remedy this monotonicity problem. We show that if we modify the original measure by taking skew information with respect to the spectral decomposition of an observable, rather than the observable itself, as a measure of coherence, then the problem disappears, and the resultant coherence measure satisfies the monotonicity. Some concrete examples are discussed and related open issues are indicated.

Numerical simulation of Forchheimer flow to a partially penetrating well with a mixed-type boundary condition

NASA Astrophysics Data System (ADS)

Mathias, Simon A.; Wen, Zhang

2015-05-01

This article presents a numerical study to investigate the combined role of partial well penetration (PWP) and non-Darcy effects concerning the performance of groundwater production wells. A finite difference model is developed in MATLAB to solve the two-dimensional mixed-type boundary value problem associated with flow to a partially penetrating well within a cylindrical confined aquifer. Non-Darcy effects are incorporated using the Forchheimer equation. The model is verified by comparison to results from existing semi-analytical solutions concerning the same problem but assuming Darcy's law. A sensitivity analysis is presented to explore the problem of concern. For constant pressure production, Non-Darcy effects lead to a reduction in production rate, as compared to an equivalent problem solved using Darcy's law. For fully penetrating wells, this reduction in production rate becomes less significant with time. However, for partially penetrating wells, the reduction in production rate persists for much larger times. For constant production rate scenarios, the combined effect of PWP and non-Darcy flow takes the form of a constant additional drawdown term. An approximate solution for this loss term is obtained by performing linear regression on the modeling results.

Redefining Academic Identity in an Evolving Higher Education Landscape

ERIC Educational Resources Information Center

Flecknoe, Sharon J.; Choate, Julia K.; Davis, Elizabeth A.; Hodgson, Yvonne M.; Johanesen, Priscilla A.; Macaulay, Janet O.; Murphy, Kim; Sturrock, Wayne J.; Rayner, Gerry M.

2017-01-01

During a period of massive upheaval to the higher education sector, the traditional academic role has undergone considerable change. One element of these changes has been the broad introduction of Education-Focused (EF) or equivalent academic positions, which focus on educational excellence, with a requirement for high quality teaching and…

Advanced bridge safety initiative, task 3 : slab bridge load rating using AASHTO methodology and finite element analysis - an analysis of 20 bridges.

DOT National Transportation Integrated Search

2011-12-01

Current AASHTO provisions for the conventional load rating of flat slab bridges rely on the equivalent strip method : of analysis for determining live load effects, this is generally regarded as overly conservative by many professional : engineers. A...

40 CFR 51.353 - Network type and program evaluation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... § 51.351 or 51.352 of this subpart. For decentralized programs other than those meeting the design... presumptively equivalent to a centralized, test-only system including comparable test elements. States may allow...-serve gasoline, pre-packaged oil, or other, non-automotive, convenience store items. At the State's...

40 CFR 51.353 - Network type and program evaluation.

Code of Federal Regulations, 2012 CFR

2012-07-01

... § 51.351 or 51.352 of this subpart. For decentralized programs other than those meeting the design... presumptively equivalent to a centralized, test-only system including comparable test elements. States may allow...-serve gasoline, pre-packaged oil, or other, non-automotive, convenience store items. At the State's...

40 CFR 51.353 - Network type and program evaluation.

Code of Federal Regulations, 2014 CFR

2014-07-01

... § 51.351 or 51.352 of this subpart. For decentralized programs other than those meeting the design... presumptively equivalent to a centralized, test-only system including comparable test elements. States may allow...-serve gasoline, pre-packaged oil, or other, non-automotive, convenience store items. At the State's...

Using Mixed Methods to Interpret Differential Item Functioning

ERIC Educational Resources Information Center

Benítez, Isabel; Padilla, José-Luis; Hidalgo Montesinos, María Dolores; Sireci, Stephen G.

2016-01-01

Analysis of differential item functioning (DIF) is often used to determine if cross-lingual assessments are equivalent across languages. However, evidence on the causes of cross-lingual DIF is still evasive. Expert appraisal is a qualitative method useful for obtaining detailed information about problematic elements in the different linguistic…

Demonstration of frequency control and CW diode laser injection control of a titanium-doped sapphire ring laser with no internal optical elements

NASA Technical Reports Server (NTRS)

Bair, Clayton H.; Brockman, Philip; Hess, Robert V.; Modlin, Edward A.

1988-01-01

Theoretical and experimental frequency narrowing studies of a Ti:sapphire ring laser with no intracavity optical elements are reported. Frequency narrowing has been achieved using a birefringent filter between a partially reflecting reverse wave suppressor mirror and the ring cavity output mirror. Results of CW diode laser injection seeding are reported.

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

Accretional evolution of a planetesimal swarm. I - A new simulation

NASA Technical Reports Server (NTRS)

Spaute, Dominique; Weidenschilling, Stuart J.; Davis, Donald R.; Marzari, Francesco

1991-01-01

This novel simulation of planetary accretion simultaneously treats many interacting heliocentric distance zones and characterizes planetesimals via Keplerian elements. The numerical code employed, in addition to following the size distribution and the orbit-element distribution of a planetesimal swarm from arbitrary size and orbit distributions, treats a small number of the largest bodies as discrete objects with individual orbits. The accretion algorithm used yields good agreement with the analytic solutions; agreement is also obtained with the results of Weatherill and Stewart (1989) for gravitational accretion of planetesimals having equivalent initial conditions.

Small-world behaviour in a system of mobile elements

NASA Astrophysics Data System (ADS)

Manrubia, S. C.; Delgado, J.; Luque, B.

2001-03-01

We analyze the propagation of activity in a system of mobile automata. A number ρLd of elements move as random walkers on a lattice of dimension d, while with a small probability p they can jump to any empty site in the system. We show that this system behaves as a Dynamic Small World (DSW) and present analytic and numerical results for several quantities. Our analysis shows that the persistence time T* (equivalent to the persistence size L* of small-world networks) scales as T* ~ (ρp)-τ, with τ = 1/(d + 1).

Taking Proof based Verified Computation a Few Steps Closer to Practicality (extended version)

DTIC Science & Technology

2012-06-27

general s2 + s, in general V’s per-instance CPU costs Issue commit queries (e + 2c) · n/β (e + 2c) · n/β Process commit responses d d Issue PCP...size (# of instances) (§2.3) e: cost of encrypting an element in F d : cost of decrypting an encrypted element f : cost of multiplying in F h: cost of...domain D (such as the integers, Z, or the rationals, Q) to equivalent constraints over a finite field, the programmer or compiler performs 3We suspect

Finite elements: Theory and application

NASA Technical Reports Server (NTRS)

Dwoyer, D. L. (Editor); Hussaini, M. Y. (Editor); Voigt, R. G. (Editor)

1988-01-01

Recent advances in FEM techniques and applications are discussed in reviews and reports presented at the ICASE/LaRC workshop held in Hampton, VA in July 1986. Topics addressed include FEM approaches for partial differential equations, mixed FEMs, singular FEMs, FEMs for hyperbolic systems, iterative methods for elliptic finite-element equations on general meshes, mathematical aspects of FEMS for incompressible viscous flows, and gradient weighted moving finite elements in two dimensions. Consideration is given to adaptive flux-corrected FEM transport techniques for CFD, mixed and singular finite elements and the field BEM, p and h-p versions of the FEM, transient analysis methods in computational dynamics, and FEMs for integrated flow/thermal/structural analysis.

Discontinuous dual-primal mixed finite elements for elliptic problems

NASA Technical Reports Server (NTRS)

Bottasso, Carlo L.; Micheletti, Stefano; Sacco, Riccardo

2000-01-01

We propose a novel discontinuous mixed finite element formulation for the solution of second-order elliptic problems. Fully discontinuous piecewise polynomial finite element spaces are used for the trial and test functions. The discontinuous nature of the test functions at the element interfaces allows to introduce new boundary unknowns that, on the one hand enforce the weak continuity of the trial functions, and on the other avoid the need to define a priori algorithmic fluxes as in standard discontinuous Galerkin methods. Static condensation is performed at the element level, leading to a solution procedure based on the sole interface unknowns. The resulting family of discontinuous dual-primal mixed finite element methods is presented in the one and two-dimensional cases. In the one-dimensional case, we show the equivalence of the method with implicit Runge-Kutta schemes of the collocation type exhibiting optimal behavior. Numerical experiments in one and two dimensions demonstrate the order accuracy of the new method, confirming the results of the analysis.

Scattering Cross Section of Sound Waves by the Modal Element Method

NASA Technical Reports Server (NTRS)

Baumeister, Kenneth J.; Kreider, Kevin L.

1994-01-01

#he modal element method has been employed to determine the scattered field from a plane acoustic wave impinging on a two dimensional body. In the modal element method, the scattering body is represented by finite elements, which are coupled to an eigenfunction expansion representing the acoustic pressure in the infinite computational domain surrounding the body. The present paper extends the previous work by developing the algorithm necessary to calculate the acoustics scattering cross section by the modal element method. The scattering cross section is the acoustical equivalent to the Radar Cross Section (RCS) in electromagnetic theory. Since the scattering cross section is evaluated at infinite distance from the body, an asymptotic approximation is used in conjunction with the standard modal element method. For validation, the scattering cross section of the rigid circular cylinder is computed for the frequency range 0.1 is less than or equal to ka is less than or equal to 100. Results show excellent agreement with the analytic solution.

Wave propagation in equivalent continuums representing truss lattice materials

DOE PAGES

Messner, Mark C.; Barham, Matthew I.; Kumar, Mukul; ...

2015-07-29

Stiffness scales linearly with density in stretch-dominated lattice meta-materials offering the possibility of very light yet very stiff structures. Current additive manufacturing techniques can assemble structures from lattice materials, but the design of such structures will require accurate, efficient simulation methods. Equivalent continuum models have several advantages over discrete truss models of stretch dominated lattices, including computational efficiency and ease of model construction. However, the development an equivalent model suitable for representing the dynamic response of a periodic truss in the small deformation regime is complicated by microinertial effects. This study derives a dynamic equivalent continuum model for periodic trussmore » structures suitable for representing long-wavelength wave propagation and verifies it against the full Bloch wave theory and detailed finite element simulations. The model must incorporate microinertial effects to accurately reproduce long wavelength characteristics of the response such as anisotropic elastic soundspeeds. Finally, the formulation presented here also improves upon previous work by preserving equilibrium at truss joints for simple lattices and by improving numerical stability by eliminating vertices in the effective yield surface.« less

Assessment of boric acid and borax using the IEHR evaluative process for assessing human developmental and reproductive toxicity of agents

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

Moore, J.A.

This document presents an evaluation of the reproductive and developmental effects of boric acid, H3BO3 (CAS Registry No. 10043-35-3) and disodium tetraborate decahydrate or borax, Na2B4O2O(CAS Registry No. 1303-96-4). The element, boron, does not exist naturally. In dilute aqueous solution and at physiological pH (7.4), the predominant species in undissociated boric acid (greater than 98%), irrespective of whether the initial material was boric acid of borax. Therefore, it is both useful and correct to compare exposures and dosages to boric acid and borax in terms of `boron equivalents`, since both materials form equivalent species in dilute aqueous solution with similarmore » systemic effects. In order to be clear in this document, the term `boron` will refer to `boron equivalents` or percent boron in boric acid and borax.« less

Modeling Percolation in Polymer Nanocomposites by Stochastic Microstructuring

PubMed Central

Soto, Matias; Esteva, Milton; Martínez-Romero, Oscar; Baez, Jesús; Elías-Zúñiga, Alex

2015-01-01

A methodology was developed for the prediction of the electrical properties of carbon nanotube-polymer nanocomposites via Monte Carlo computational simulations. A two-dimensional microstructure that takes into account waviness, fiber length and diameter distributions is used as a representative volume element. Fiber interactions in the microstructure are identified and then modeled as an equivalent electrical circuit, assuming one-third metallic and two-thirds semiconductor nanotubes. Tunneling paths in the microstructure are also modeled as electrical resistors, and crossing fibers are accounted for by assuming a contact resistance associated with them. The equivalent resistor network is then converted into a set of linear equations using nodal voltage analysis, which is then solved by means of the Gauss–Jordan elimination method. Nodal voltages are obtained for the microstructure, from which the percolation probability, equivalent resistance and conductivity are calculated. Percolation probability curves and electrical conductivity values are compared to those found in the literature. PMID:28793594

Ion-Conserving Modified Poisson-Boltzmann Theory Considering a Steric Effect in an Electrolyte

NASA Astrophysics Data System (ADS)

Sugioka, Hideyuki

2016-12-01

The modified Poisson-Nernst-Planck (MPNP) and modified Poisson-Boltzmann (MPB) equations are well known as fundamental equations that consider a steric effect, which prevents unphysical ion concentrations. However, it is unclear whether they are equivalent or not. To clarify this problem, we propose an improved free energy formulation that considers a steric limit with an ion-conserving condition and successfully derive the ion-conserving modified Poisson-Boltzmann (IC-MPB) equations that are equivalent to the MPNP equations. Furthermore, we numerically examine the equivalence by comparing between the IC-MPB solutions obtained by the Newton method and the steady MPNP solutions obtained by the finite-element finite-volume method. A surprising aspect of our finding is that the MPB solutions are much different from the MPNP (IC-MPB) solutions in a confined space. We consider that our findings will significantly contribute to understanding the surface science between solids and liquids.

Equivalent circuit and optimum design of a multilayer laminated piezoelectric transformer.

PubMed

Dong, Shuxiang; Carazo, Alfredo Vazquez; Park, Seung Ho

2011-12-01

A multilayer laminated piezoelectric Pb(Zr(1-x)Ti(x))O(3) (PZT) ceramic transformer, operating in a half- wavelength longitudinal resonant mode (λ/2 mode), has been analyzed. This piezoelectric transformer is composed of one thickness-polarized section (T-section) for exciting the longitudinal mechanical vibrations, two longitudinally polarized sections (L-section) for generating high-voltage output, and two insulating layers laminated between the T-section and L-section layers to provide insulation between the input and output sections. Based on the piezoelectric constitutive and motion equations, an electro-elasto-electric (EEE) equivalent circuit has been developed, and correspondingly, an effective EEE coupling coefficient was proposed for optimum design of this multilayer transformer. Commercial finite element analysis software is used to determine the validity of the developed equivalent circuit. Finally, a prototype sample was manufactured and experimental data was collected to verify the model's validity.

The schemes and methods for producing of the visual security features used in the color hologram stereography

NASA Astrophysics Data System (ADS)

Lushnikov, D. S.; Zherdev, A. Y.; Odinokov, S. B.; Markin, V. V.; Smirnov, A. V.

2017-05-01

Visual security elements used in color holographic stereograms - three-dimensional colored security holograms - and methods their production is describes in this article. These visual security elements include color micro text, color-hidden image, the horizontal and vertical flip - flop effects by change color and image. The article also presents variants of optical systems that allow record the visual security elements as part of the holographic stereograms. The methods for solving of the optical problems arising in the recording visual security elements are presented. Also noted perception features of visual security elements for verification of security holograms by using these elements. The work was partially funded under the Agreement with the RF Ministry of Education and Science № 14.577.21.0197, grant RFMEFI57715X0197.

An Experimental Investigation on the Ultimate Strength of Partially Infilled: Braced Steel Frames

NASA Astrophysics Data System (ADS)

Dubey, Shailendra Kumar Damodar; Kute, Sunil Y.

2017-12-01

Infilled walls are usually, considered as non-structural elements. However, these walls are effective in carrying lateral loads. In this regard, an experimental investigation was planned and conducted to study the effect of braced and partially infilled steel frames with cement mortar and concrete in comparison to the bare frames. All these frames were tested up to collapse and subjected only to horizontal loads to obtain an effective and possible solution for soft storey which are generally not infilled. In comparison to bare steel frames, partially infilled frames have an increase of lateral load capacity by 45-60%. Central bracing is more effective than that of the corner bracing. For the same load partially infilled frames have significantly less deflection than that of the bare frames. A reduced load factor is suggested for the design of soft storey columns with the partial infills. A mathematical model has been proposed to calculate the theoretical ultimate load for the braced, cement mortar and concrete partial infilled frames.

Calculation of Collisional Cross Sections for the 2P3/2 - 2P1/2 Transition in Alkali-Noble Gas Systems

DTIC Science & Technology

2010-03-01

matrix elements. From scattering matrix elements for several different effective potential values and using the Method of Partial Waves[7], the...scattering matrix elements. Through the Method of Par- tial Waves[7], the procedure was repeated for several different effective potentials. The...section calculations. It is important to note that lmax may differ for σel and σi→f . This method may only be used if both σi→f and σel have

Topological States in Partially-PT -Symmetric Azimuthal Potentials

NASA Astrophysics Data System (ADS)

Kartashov, Yaroslav V.; Konotop, Vladimir V.; Torner, Lluis

2015-11-01

We introduce partially-parity-time (p PT ) -symmetric azimuthal potentials composed from individual PT -symmetric cells located on a ring, where two azimuthal directions are nonequivalent in a sense that in such potential excitations carrying topological dislocations exhibit different dynamics for different directions of energy circulation in the initial field distribution. Such nonconservative ratchetlike structures support rich families of stable vortex solitons in cubic nonlinear media, whose properties depend on the sign of the topological charge due to the nonequivalence of azimuthal directions. In contrast, oppositely charged vortex solitons remain equivalent in similar fully-P T -symmetric potentials. The vortex solitons in the p P T - and P T -symmetric potentials are shown to feature qualitatively different internal current distributions, which are described by different discrete rotation symmetries of the intensity profiles.

Discrete Element Modelling of Floating Debris

NASA Astrophysics Data System (ADS)

Mahaffey, Samantha; Liang, Qiuhua; Parkin, Geoff; Large, Andy; Rouainia, Mohamed

2016-04-01

Flash flooding is characterised by high velocity flows which impact vulnerable catchments with little warning time and as such, result in complex flow dynamics which are difficult to replicate through modelling. The impacts of flash flooding can be made yet more severe by the transport of both natural and anthropogenic debris, ranging from tree trunks to vehicles, wheelie bins and even storage containers, the effects of which have been clearly evident during recent UK flooding. This cargo of debris can have wide reaching effects and result in actual flood impacts which diverge from those predicted. A build-up of debris may lead to partial channel blockage and potential flow rerouting through urban centres. Build-up at bridges and river structures also leads to increased hydraulic loading which may result in damage and possible structural failure. Predicting the impacts of debris transport; however, is difficult as conventional hydrodynamic modelling schemes do not intrinsically include floating debris within their calculations. Subsequently a new tool has been developed using an emerging approach, which incorporates debris transport through the coupling of two existing modelling techniques. A 1D hydrodynamic modelling scheme has here been coupled with a 2D discrete element scheme to form a new modelling tool which predicts the motion and flow-interaction of floating debris. Hydraulic forces arising from flow around the object are applied to instigate its motion. Likewise, an equivalent opposing force is applied to fluid cells, enabling backwater effects to be simulated. Shock capturing capabilities make the tool applicable to predicting the complex flow dynamics associated with flash flooding. The modelling scheme has been applied to experimental case studies where cylindrical wooden dowels are transported by a dam-break wave. These case studies enable validation of the tool's shock capturing capabilities and the coupling technique applied between the two numerical schemes. The results show that the tool is able to adequately replicate water depth and depth-averaged velocity of a dam-break wave, as well as velocity and displacement of floating cylindrical elements, thus validating its shock capturing capabilities and the coupling technique applied for this simple test case. Future development of the tool will incorporate a 2D hydrodynamic scheme and a 3D discrete element scheme in order to model the more complex processes associated with debris transport.

3 d printing of 2 d N=(0,2) gauge theories

NASA Astrophysics Data System (ADS)

Franco, Sebastián; Hasan, Azeem

2018-05-01

We introduce 3 d printing, a new algorithm for generating 2 d N=(0,2) gauge theories on D1-branes probing singular toric Calabi-Yau 4-folds using 4 d N=1 gauge theories on D3-branes probing toric Calabi-Yau 3-folds as starting points. Equivalently, this method produces brane brick models starting from brane tilings. 3 d printing represents a significant improvement with respect to previously available tools, allowing a straightforward determination of gauge theories for geometries that until now could only be tackled using partial resolution. We investigate the interplay between triality, an IR equivalence between different 2 d N=(0,2) gauge theories, and the freedom in 3 d printing given an underlying Calabi-Yau 4-fold. Finally, we present the first discussion of the consistency and reduction of brane brick models.

The Strengths and Difficulties Questionnaire (SDQ): Factor Structure and Gender Equivalence in Norwegian Adolescents

PubMed Central

Hysing, Mari; Skogen, Jens Christoffer; Breivik, Kyrre

2016-01-01

Although frequently used with older adolescents, few studies of the factor structure, internal consistency and gender equivalence of the SDQ exists for this age group, with inconsistent findings. In the present study, confirmatory factor analysis (CFA) was used to evaluate the five-factor structure of the SDQ in a population sample of 10,254 16–18 year-olds from the youth@hordaland study. Measurement invariance across gender was assessed using multigroup CFA. A modestly modified five-factor solution fitted the data acceptably, accounting for one cross loading and some local dependencies. Importantly, partial measurement non-invariance was identified, with differential item functioning in eight items, and higher correlations between emotional and conduct problems for boys compared to girls. Implications for use clinically and in research are discussed. PMID:27138259

Determination of nongeometric effects: equivalence between Artmann's and Tamir's generalized methods.

PubMed

Perez, Liliana I; Echarri, Rodolfo M; Garea, María T; Santiago, Guillermo D

2011-03-01

This work shows that all first- and second-order nongeometric effects on propagation, total or partial reflection, and transmission can be understood and evaluated considering the superposition of two plane waves. It also shows that this description yields results that are qualitatively and quantitatively compatible with those obtained by Fourier analysis of beams with Gaussian intensity distribution in any type of interface. In order to show this equivalence, we start by describing the first- and second-order nongeometric effects, and we calculate them analytically by superposing two plane waves. Finally, these results are compared with those obtained for the nongeometric effects of Gaussian beams in isotropic interfaces and are applied to different types of interfaces. A simple analytical expression for the angular shift is obtained considering the transmission of an extraordinary beam in a uniaxial-isotropic interface.

Simplified microstrip discontinuity modeling using the transmission line matrix method interfaced to microwave CAD

NASA Astrophysics Data System (ADS)

Thompson, James H.; Apel, Thomas R.

1990-07-01

A technique for modeling microstrip discontinuities is presented which is derived from the transmission line matrix method of solving three-dimensional electromagnetic problems. In this technique the microstrip patch under investigation is divided into an integer number of square and half-square (triangle) subsections. An equivalent lumped-element model is calculated for each subsection. These individual models are then interconnected as dictated by the geometry of the patch. The matrix of lumped elements is then solved using either of two microwave CAD software interfaces with each port properly defined. Closed-form expressions for the lumped-element representation of the individual subsections is presented and experimentally verified through the X-band frequency range. A model demonstrating the use of symmetry and block construction of a circuit element is discussed, along with computer program development and CAD software interface.

Equivalent Young's modulus of composite resin for simulation of stress during dental restoration.

PubMed

Park, Jung-Hoon; Choi, Nak-Sam

2017-02-01

For shrinkage stress simulation in dental restoration, the elastic properties of composite resins should be acquired beforehand. This study proposes a formula to measure the equivalent Young's modulus of a composite resin through a calculation scheme of the shrinkage stress in dental restoration. Two types of composite resins remarkably different in the polymerization shrinkage strain were used for experimental verification: the methacrylate-type (Clearfil AP-X) and the silorane-type (Filtek P90). The linear shrinkage strains of the composite resins were gained through the bonded disk method. A formula to calculate the equivalent Young's moduli of composite resin was derived on the basis of the restored ring substrate. Equivalent Young's moduli were measured for the two types of composite resins through the formula. Those values were applied as input to a finite element analysis (FEA) for validation of the calculated shrinkage stress. Both of the measured moduli through the formula were appropriate for stress simulation of dental restoration in that the shrinkage stresses calculated by the FEA were in good agreement within 3.5% with the experimental values. The concept of equivalent Young's modulus so measured could be applied for stress simulation of 2D and 3D dental restoration. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Metrics for Assessing the Quality of Groundwater Used for Public Supply, CA, USA: Equivalent-Population and Area.

PubMed

Belitz, Kenneth; Fram, Miranda S; Johnson, Tyler D

2015-07-21

Data from 11,000 public supply wells in 87 study areas were used to assess the quality of nearly all of the groundwater used for public supply in California. Two metrics were developed for quantifying groundwater quality: area with high concentrations (km(2) or proportion) and equivalent-population relying upon groundwater with high concentrations (number of people or proportion). Concentrations are considered high if they are above a human-health benchmark. When expressed as proportions, the metrics are area-weighted and population-weighted detection frequencies. On a statewide-scale, about 20% of the groundwater used for public supply has high concentrations for one or more constituents (23% by area and 18% by equivalent-population). On the basis of both area and equivalent-population, trace elements are more prevalent at high concentrations than either nitrate or organic compounds at the statewide-scale, in eight of nine hydrogeologic provinces, and in about three-quarters of the study areas. At a statewide-scale, nitrate is more prevalent than organic compounds based on area, but not on the basis of equivalent-population. The approach developed for this paper, unlike many studies, recognizes the importance of appropriately weighting information when changing scales, and is broadly applicable to other areas.

Chapter 13 Petrogenesis of the Campanian Ignimbrite: implications for crystal-melt separation and open-system processes from major and trace elements and Th isotopic data

USGS Publications Warehouse

Bohrson, W.A.; Spera, F.J.; Fowler, S.J.; Belkin, H.E.; de Vivo, B.; Rolandi, G.

2006-01-01

The Campanian Ignimbrite is a large-volume trachytic to phonolitic ignimbrite that was deposited at ???39.3 ka and represents one of a number of highly explosive volcanic events that have occurred in the region near Naples, Italy. Thermodynamic modeling using the MELTS algorithm reveals that major element variations are dominated by crystal-liquid separation at 0.15 GPa. Initial dissolved H2O content in the parental melt is ???3 wt.% and the magmatic system fugacity of oxygen was buffered along QFM+1. Significantly, MELTS results also indicate that the liquid line of descent is marked by a large change in the proportion of melt (from 0.46 to 0.09) at ???884??C, which leads to a discontinuity in melt composition (i.e., a compositional gap) and different thermodynamic and transport properties of melt and magma across the gap. Crystallization of alkali feldspar and plagioclase dominates the phase assemblage at this pseudo-invariant point temperature of ???884??C. Evaluation of the variations in the trace elements Zr, Nb, Th, U, Rb, Sm, and Sr using a mass balance equation that accounts for changing bulk mineral-melt partition coefficients as crystallization occurs indicates that crystal-liquid separation and open-system processes were important. Th isotope data yield an apparent isochron that is ???20 kyr younger than the age of the deposit, and age-corrected Th isotope data indicate that the magma body was an open system at the time of eruption. Because open-system behavior can profoundly change isotopic and elemental characteristics of a magma body, these Th results illustrate that it is critical to understand the contribution that open-system processes make to magmatic systems prior to assigning relevance to age or timescale information derived from such systems. Fluid-magma interaction has been proposed as a mechanism to change isotopic and elemental characteristics of magma bodies, but an evaluation of the mass and thermal constraints on such a process suggests large-scale interaction is unlikely. In the case of the magma body associated with the Campanian Ignimbrite, the most likely source of the open-system signatures is assimilation of partial melts of compositionally heterogeneous basement composed of cumulates and intrusive equivalents of volcanic activity that has characterized the Campanian region for over 300 kyr. ?? 2006 Elsevier B.V. All rights reserved.

Geochemistry and petrogenesis of a peralkaline granite complex from the Midian Mountains, Saudi Arabia

NASA Astrophysics Data System (ADS)

Harris, N. B. W.; Marriner, G. F.

1980-10-01

A zoned intrusion with a biotite granodiorite core and arfvedsonite granite rim represents the source magma for an albitised granite plug near its eastern margin and radioactive siliceous veins along its western margin. A study of selected REE and trace elements of samples from this complex reveals that the albitised granite plug has at least a tenfold enrichment in Zr, Hf, Nb, Ta, Y, Th, U and Sr, and a greatly enhanced heavy/light REE ratio compared with the peralkaline granite. The siliceous veins have even stronger enrichment of these trace elements, but a heavy/light REE ratio and negative eu anomaly similar to the peralkaline granite. It is suggested that the veins were formed from acidic volatile activity and the plug from a combination of highly fractionated magma and co-existing alkaline volatile phase. The granodiorite core intrudes the peralkaline granite and has similar trace element geochemistry. The peralkaline granite is probably derived from the partial melting of the lower crust in the presence of halide-rich volatiles, and the granodiorite from further partial melting under volatile-free conditions.

Core formation in the shergottite parent body and comparison with the earth

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

Treiman, A.H.; Jones, J.H.; Drake, M.J.

1987-03-30

The mantle of the shergottite parent body (SPB) is depleted relative to the bulk SPB in siderophile and chalcophile elements; these elements are inferred to reside in the SPB's core. Our chemical model of these depletions rests on a physically plausible process of segregation of partially molten metal form partially molten silicates as the SPB grows and is heated above silicate and metallic solidi during accretion. Metallic and silicate phases equilibrate at low pressures as new material is accreted to the SPB surface. Later movement of the metallic phases to the planet's center is so rapid that high-pressure equilibration ismore » insignificant. Partitioning of siderophile and chalcophile elements among solid and liquid metal and silicate determines their abundances in the SPB mantle. Using partition coefficients and the SPB mantle composition determined in earlier studies, we model the abundances of Ag, Au, Co, Ga, Mo, Ni, P, Re, S, and W with free parameters being oxygen fugacity, proportion of solid metal formed, proportion of metallic liquid formed, and proportion of silicate that is molten.« less

Application of Finite Element to Evaluate Material with Small Modulus of Elasticity

DTIC Science & Technology

2013-03-01

14  Figure 8: Cross-sectional diagram of thorax highlighting the various muscle groups in the Hawkmoth and the interaction with Exoskeleton ...44  Figure 26: Partially Dissected Moth highlighting the point of incision of the exoskeleton (wings are removed...applications to the exoskeleton of the hawkmoth are examined. The formulation of these equations is discussed in Chapter 2 and the finite element model is

Inter-costal Liver Ablation Under Real Time MR-Thermometry With Partial Activation Of A HIFU Phased Array Transducer

NASA Astrophysics Data System (ADS)

Quesson, Bruno; Merle, Mathilde; Köhler, Max; Mougenot, Charles; Roujol, Sebastien; de Senneville, Baudouin Denis; Moonen, Chrit

2010-03-01

HIFU ablation of tumours located inside the liver is hampered by the rib cage, which partially obstructs the beam path and may create adverse effects such as skin burns. This study presents a method for selectively deactivating the transducer elements causing undesired temperature increases near the bones. A manual segmentation of the bones visualized on 3D anatomical MR images acquired prior to sonication was performed to identify the beam obstruction. The resulting mask was projected (ray tracing starting from the focal point) on the transducer and elements with more than 50% obstruction of their active surface were deactivated. The effectiveness of the method for HIFU ablations is demonstrated ex vivo and in vivo in the liver of pigs with real-time MR thermometry, using the proton resonant frequency (PRF) method. For both ex vivo and in vivo experiments, the temperature increase near the bones was significantly reduced when the elements located in front of the ribs were deactivated. The temperature evolution at the focal point were similar, indicative of the absence of loss of heating efficacy when the elements were deactivated. This method is simple, rapid and reliable and allows to perform intercostal MRgHIFU ablation of the liver while sparing the ribs.

Implications of the licensure of a partially efficacious malaria vaccine on evaluating second-generation vaccines

PubMed Central

2013-01-01

Background Malaria is a leading cause of morbidity and mortality, with approximately 225 million clinical episodes and >1.2 million deaths annually attributed to malaria. Development of a highly efficacious malaria vaccine will offer unparalleled possibilities for disease prevention and remains a key priority for long-term malaria control and elimination. Discussion The Malaria Vaccine Technology Roadmap’s goal is to 'develop and license a first-generation malaria vaccine that has protective efficacy of more than 50%’. To date, malaria vaccine candidates have only been shown to be partially efficacious (approximately 30% to 60%). However, licensure of a partially effective vaccine will create a number of challenges for the development and progression of new, potentially more efficacious, malaria vaccines in the future. In this opinion piece we discuss the methodological, logistical and ethical issues that may impact on the feasibility and implementation of superiority, non-inferiority and equivalence trials to assess second generation malaria vaccines in the advent of the licensure of a partially efficacious malaria vaccine. Conclusions Selecting which new malaria vaccines go forward, and defining appropriate methodology for assessment in logistically challenging clinical trials, is crucial. It is imperative that the scientific community considers all the issues and starts planning how second-generation malaria vaccines will advance in the advent of licensure of a partially effective vaccine. PMID:24228861

Correlation-coefficient-based fast template matching through partial elimination.

PubMed

Mahmood, Arif; Khan, Sohaib

2012-04-01

Partial computation elimination techniques are often used for fast template matching. At a particular search location, computations are prematurely terminated as soon as it is found that this location cannot compete with an already known best match location. Due to the nonmonotonic growth pattern of the correlation-based similarity measures, partial computation elimination techniques have been traditionally considered inapplicable to speed up these measures. In this paper, we show that partial elimination techniques may be applied to a correlation coefficient by using a monotonic formulation, and we propose basic-mode and extended-mode partial correlation elimination algorithms for fast template matching. The basic-mode algorithm is more efficient on small template sizes, whereas the extended mode is faster on medium and larger templates. We also propose a strategy to decide which algorithm to use for a given data set. To achieve a high speedup, elimination algorithms require an initial guess of the peak correlation value. We propose two initialization schemes including a coarse-to-fine scheme for larger templates and a two-stage technique for small- and medium-sized templates. Our proposed algorithms are exact, i.e., having exhaustive equivalent accuracy, and are compared with the existing fast techniques using real image data sets on a wide variety of template sizes. While the actual speedups are data dependent, in most cases, our proposed algorithms have been found to be significantly faster than the other algorithms.

Trace element behavior and P-T-t evolution during partial melting of exhumed eclogite in the North Qaidam UHPM belt (NW China): Implications for adakite genesis

NASA Astrophysics Data System (ADS)

Zhang, Guibin; Niu, Yaoling; Song, Shuguang; Zhang, Lifei; Tian, Zuolin; Christy, Andrew G.; Han, Lei

2015-06-01

We have studied trace element behavior and timing of decompression melting of UHP rocks during exhumation recorded in the magmatic products, i.e., the melt phase (leucosomes), cumulate (garnetite) and residue (amphibolitized eclogite) from a single outcrop in the south Dulan area, North Qaidam UHPM belt, NW China. Two distinct episodes of partial melting are recognized. First, Grt-free tonalitic-trondhjemitic leucosome melts with higher silica crystallized at 424.0 ± 2.7 Ma. Garnets grew in the leucosome melt but fractionated out to form garnetite cumulates along with Ti-rich phases (rutile and titanite), strengthening the adakitic signature of the leucosome. Later Grt-bearing leucosome melts with an age of 412.4 ± 2.9 Ma cross-cut boudins and layers of amphibolitized eclogite. Geochemical investigation of bulk-rocks and in situ minerals verifies the genetic relationship between the amphibolitized eclogite and the tonalitic-trondhjemitic melts. Zircons from the amphibolitized eclogite have older (> 700 Ma) protolith ages, with subsequent eclogite-facies metamorphism, retrograde granulite-facies overprinting and partial melting. Phase modeling and Zr-in-rutile thermometry calculations in combination with zircon geochronology reveal the evolution P-T-t path for the exhumation and the partial melting of the deeply subducted continental crust at the North Qaidam subduction zone in the Early Paleozoic.

Negative regulation of early polyomavirus expression in mouse embryonal carcinoma cells.

PubMed Central

Cremisi, C; Babinet, C

1986-01-01

Embryonal carcinoma cells are resistant to infection by polyomavirus (Py). We showed that this block was partially removed by inhibiting protein synthesis temporarily. The block was also partially removed when Py was coinfected with simian virus 40. Cycloheximide treatment of cells infected with Py mutants able to grow on PCC4 embryonal carcinoma cells led to 3- to 10-fold increases in the production of T-antigen-positive cells. At 31 degrees C, Py T-antigen expression was enhanced when the cells were treated with cycloheximide. We suggest that a negative labile regulatory protein(s) is synthesized in PCC4 cells, preventing the initiation of early Py transcription by binding to the noncoding sequence, especially the enhancer element B and perhaps also element A, and that the Py mutants retained a binding site(s). PMID:3016339

Quantitative Computed Tomography (QCT) derived Bone Mineral Density (BMD) in finite element studies: a review of the literature.

PubMed

Knowles, Nikolas K; Reeves, Jacob M; Ferreira, Louis M

2016-12-01

Finite element modeling of human bone provides a powerful tool to evaluate a wide variety of outcomes in a highly repeatable and parametric manner. These models are most often derived from computed tomography data, with mechanical properties related to bone mineral density (BMD) from the x-ray energy attenuation provided from this data. To increase accuracy, many researchers report the use of quantitative computed tomography (QCT), in which a calibration phantom is used during image acquisition to improve the estimation of BMD. Since model accuracy is dependent on the methods used in the calculation of BMD and density-mechanical property relationships, it is important to use relationships developed for the same anatomical location and using the same scanner settings, as these may impact model accuracy. The purpose of this literature review is to report the relationships used in the conversion of QCT equivalent density measures to ash, apparent, and/or tissue densities in recent finite element (FE) studies used in common density-modulus relationships. For studies reporting experimental validation, the validation metrics and results are presented. Of the studies reviewed, 29% reported the use of a dipotassium phosphate (K 2 HPO 4 ) phantom, 47% a hydroxyapatite (HA) phantom, 13% did not report phantom type, 7% reported use of both K 2 HPO 4 and HA phantoms, and 4% alternate phantom types. Scanner type and/or settings were omitted or partially reported in 31% of studies. The majority of studies used densitometric and/or density-modulus relationships derived from different anatomical locations scanned in different scanners with different scanner settings. The methods used to derive various densitometric relationships are reported and recommendations are provided toward the standardization of reporting metrics. This review assessed the current state of QCT-based FE modeling with use of clinical scanners. It was found that previously developed densitometric relationships vary by anatomical location, scanner type and settings. Reporting of all parameters used when referring to previously developed relationships, or in the development of new relationships, may increase the accuracy and repeatability of future FE models.

The Indirect Boundary Element Method (IBEM) for Seismic Response of Topographical Irregularities in Layered Media

NASA Astrophysics Data System (ADS)

Contreras Zazueta, M. A.; Perton, M.; Sanchez-Sesma, F. J.; Sánchez-Alvaro, E.

2013-12-01

The seismic hazard assessment of extended developments, such as a dam, a bridge or a pipeline, needs the strong ground motion simulation taking into account the effects of surface geology. In many cases the incoming wave field can be obtained from attenuation relations or simulations for layered media using Discrete Wave Number (DWN). Sometimes there is a need to include in simulations the seismic source as well. A number of methods to solve these problems have been developed. Among them the Finite Element and Finite Difference Methods (FEM and FDM) are generally preferred because of the facility of use. Nevertheless, the analysis of realistic dynamic loading induced by earthquakes requires a thinner mesh of the entire domain to consider high frequencies. Consequently this may imply a high computational cost. The Indirect Boundary Element Method (IBEM) can also be employed. Here it is used to study the response of a site to historical seismic activity. This method is particularly suited to model wave propagation through wide areas as it requires only the meshing of boundaries. Moreover, it is well suited to represent finely the diffraction that can occur on a fault. However, the IBEM has been applied mainly to simple geometrical configurations. In this communication significant refinements of the formulation are presented. Using IBEM we can simulate wave propagation in complex geometrical configurations such as a stratified medium crossed by thin faults or having a complex topography. Two main developments are here described; one integrates the DWN method inside the IBEM in order to represent the Green's functions of stratified media with relatively low computational cost but assuming unbounded parallel flat layers, and the other is the extension of IBEM to deal with multi-regions in contact which allows more versatility with a higher computational cost compared to the first one but still minor to an equivalent FEM formulation. The two approaches are fully described here and their results compared within the hazard studies of CFE-Las Cruces, Nayarit, Mexico, hydroelectrical project. ACKNOWLEDGEMENTS. This study is partially supported by DGAPA-UNAM under Project IN104712.