NASA Astrophysics Data System (ADS)
Gloerfelt, X.; Bailly, C.; Juvé, D.
2003-09-01
The goal of this paper is to investigate the acoustic field generated by the flow over a cavity using two different and complementary numerical methods. First, a Direct Numerical Simulation of the 2-D compressible Navier-Stokes equations is performed to obtain directly the radiated noise. The results of the acoustic and aerodynamic fields are compared to the experimental data in the literature. Second, this reference solution is compared to solutions provided by hybrid methods using the flowfield computed inside the cavity combined with an integral formulation to evaluate the far-field noise. Numerical issues of three integral methods are studied: the Ffowcs Williams and Hawkings analogy that extends Lighthill's theory to account for solid boundaries and two Wave Extrapolation Methods from a control surface, the Kirchhoff and porous Ffowcs Williams and Hawkings methods. All methods show a good agreement with the Direct Numerical Simulation, but the first one is more expensive owing to an additional volume integral. However, the analogy can help in the analysis of wave patterns, by separating the direct waves from the reflected ones. The wave extrapolation methods from a surface are more efficient and provide a complementary tool to extend Computational Aeroacoustics near field to the very far field.
Tuning of PID controllers for integrating systems using direct synthesis method.
Anil, Ch; Padma Sree, R
2015-07-01
A PID controller is designed for various forms of integrating systems with time delay using direct synthesis method. The method is based on comparing the characteristic equation of the integrating system and PID controller with a filter with the desired characteristic equation. The desired characteristic equation comprises of multiple poles which are placed at the same desired location. The tuning parameter is adjusted so as to achieve the desired robustness. Tuning rules in terms of process parameters are given for various forms of integrating systems. The tuning parameter can be selected for the desired robustness by specifying Ms value. The proposed controller design method is applied to various transfer function models and to the nonlinear model equations of jacketed CSTR to show its effectiveness and applicability.
A robust direct-integration method for rotorcraft maneuver and periodic response
NASA Technical Reports Server (NTRS)
Panda, Brahmananda
1992-01-01
The Newmark-Beta method and the Newton-Raphson iteration scheme are combined to develop a direct-integration method for evaluating the maneuver and periodic-response expressions for rotorcraft. The method requires the generation of Jacobians and includes higher derivatives in the formulation of the geometric stiffness matrix to enhance the convergence of the system. The method leads to effective convergence with nonlinear structural dynamics and aerodynamic terms. Singularities in the matrices can be addressed with the method as they arise from a Lagrange multiplier approach for coupling equations with nonlinear constraints. The method is also shown to be general enough to handle singularities from quasisteady control-system models. The method is shown to be more general and robust than the similar 2GCHAS method for analyzing rotorcraft dynamics.
Corcelli, S.A.; Kress, J.D.; Pratt, L.R.
1995-08-07
This paper develops and characterizes mixed direct-iterative methods for boundary integral formulations of continuum dielectric solvation models. We give an example, the Ca{sup ++}{hor_ellipsis}Cl{sup {minus}} pair potential of mean force in aqueous solution, for which a direct solution at thermal accuracy is difficult and, thus for which mixed direct-iterative methods seem necessary to obtain the required high resolution. For the simplest such formulations, Gauss-Seidel iteration diverges in rare cases. This difficulty is analyzed by obtaining the eigenvalues and the spectral radius of the non-symmetric iteration matrix. This establishes that those divergences are due to inaccuracies of the asymptotic approximations used in evaluation of the matrix elements corresponding to accidental close encounters of boundary elements on different atomic spheres. The spectral radii are then greater than one for those diverging cases. This problem is cured by checking for boundary element pairs closer than the typical spatial extent of the boundary elements and for those cases performing an ``in-line`` Monte Carlo integration to evaluate the required matrix elements. These difficulties are not expected and have not been observed for the thoroughly coarsened equations obtained when only a direct solution is sought. Finally, we give an example application of hybrid quantum-classical methods to deprotonation of orthosilicic acid in water.
Study of methods for direct optical address of integrated optical circuits
NASA Technical Reports Server (NTRS)
Wood, V. E.; Verber, C. M.
1979-01-01
Methods for introducing optical information directly, without intervening recording and storage steps, into integrated optical data-processing devices are surveyed. The information is taken to be in the form of a one-dimensional variation of intensity across the beam. Physical phenomena that may be utilized are evaluated, and the most suitable presently known classes of materials for exploitation of each type of interaction are discussed. A variety of possible device configurations are suggested and general principles are outlined whereby many more device types can be generated. A simple experimental device was demonstrated and its operation was analyzed.
Direction and Integration of Experimental Ground Test Capabilities and Computational Methods
NASA Technical Reports Server (NTRS)
Dunn, Steven C.
2016-01-01
This paper groups and summarizes the salient points and findings from two AIAA conference panels targeted at defining the direction, with associated key issues and recommendations, for the integration of experimental ground testing and computational methods. Each panel session utilized rapporteurs to capture comments from both the panel members and the audience. Additionally, a virtual panel of several experts were consulted between the two sessions and their comments were also captured. The information is organized into three time-based groupings, as well as by subject area. These panel sessions were designed to provide guidance to both researchers/developers and experimental/computational service providers in defining the future of ground testing, which will be inextricably integrated with the advancement of computational tools.
McCammon, R.B.; Finch, W.I.; Kork, J.O.; Bridges, N.J.
1994-01-01
An integrated data-directed numerical method has been developed to estimate the undiscovered mineral endowment within a given area. The method has been used to estimate the undiscovered uranium endowment in the San Juan Basin, New Mexico, U.S.A. The favorability of uranium concentration was evaluated in each of 2,068 cells defined within the Basin. Favorability was based on the correlated similarity of the geologic characteristics of each cell to the geologic characteristics of five area-related deposit models. Estimates of the undiscovered endowment for each cell were categorized according to deposit type, depth, and cutoff grade. The method can be applied to any mineral or energy commodity provided that the data collected reflect discovered endowment. ?? 1994 Oxford University Press.
Bryan, B.J.; Flanders, H.E. Jr.
1992-12-31
Seismic qualification of Class I nuclear components is accomplished using a variety of analytical methods. This paper compares the results of time history dynamic analyses of a heat exchanger support structure using response spectrum and time history direct integration analysis methods. Dynamic analysis is performed on the detailed component models using the two methods. A nonlinear elastic model is used for both the response spectrum and direct integration methods. A nonlinear model which includes friction and nonlinear springs, is analyzed using time history input by direct integration. The loads from the three cases are compared.
A facile method for integrating direct-write devices into three-dimensional printed parts
NASA Astrophysics Data System (ADS)
Chang, Yung-Hang; Wang, Kan; Wu, Changsheng; Chen, Yiwen; Zhang, Chuck; Wang, Ben
2015-06-01
Integrating direct-write (DW) devices into three-dimensional (3D) printed parts is key to continuing innovation in engineering applications such as smart material systems and structural health monitoring. However, this integration is challenging because: (1) most 3D printing techniques leave rough or porous surfaces if they are untreated; (2) the thermal sintering process required for most conductive inks could degrade the polymeric materials of 3D printed parts; and (3) the extensive pause needed for the DW process during layer-by-layer fabrication may cause weaker interlayer bonding and create structural weak points. These challenges are rather common during the insertion of conductive patterns inside 3D printed structures. As an avoidance tactic, we developed a simple ‘print-stick-peel’ method to transfer the DW device from the polytetrafluoroethylene or perfluoroalkoxy alkanes film onto any layer of a 3D printed object. This transfer can be achieved using the self-adhesion of 3D printing materials or applying additional adhesive. We demonstrated this method by transferring Aerosol Jet® printed strain sensors into parts fabricated by PolyJet™ printing. This report provides an investigation and discussion on the sensitivity, reliability, and influence embedding the sensor has on mechanical properties.
Transient Response of Shells of Revolution by Direct Integration and Modal Superposition Methods
NASA Technical Reports Server (NTRS)
Stephens, W. B.; Adelman, H. M.
1974-01-01
The results of an analytical effort to obtain and evaluate transient response data for a cylindrical and a conical shell by use of two different approaches: direct integration and modal superposition are described. The inclusion of nonlinear terms is more important than the inclusion of secondary linear effects (transverse shear deformation and rotary inertia) although there are thin-shell structures where these secondary effects are important. The advantages of the direct integration approach are that geometric nonlinear and secondary effects are easy to include and high-frequency response may be calculated. In comparison to the modal superposition technique the computer storage requirements are smaller. The advantages of the modal superposition approach are that the solution is independent of the previous time history and that once the modal data are obtained, the response for repeated cases may be efficiently computed. Also, any admissible set of initial conditions can be applied.
NASA Technical Reports Server (NTRS)
Young, D. P.; Woo, A. C.; Bussoletti, J. E.; Johnson, F. T.
1986-01-01
A general method is developed combining fast direct methods and boundary integral equation methods to solve Poisson's equation on irregular exterior regions. The method requires O(N log N) operations where N is the number of grid points. Error estimates are given that hold for regions with corners and other boundary irregularities. Computational results are given in the context of computational aerodynamics for a two-dimensional lifting airfoil. Solutions of boundary integral equations for lifting and nonlifting aerodynamic configurations using preconditioned conjugate gradient are examined for varying degrees of thinness.
New types of multisoliton solutions of some integrable equations via direct methods
NASA Astrophysics Data System (ADS)
Burde, Georgy I.
2016-06-01
Exact explicit solutions, which describe new multisoliton dynamics, have been identified for some KdV type equations using direct methods devised for this purpose. It is found that the equations, having multi-soliton solutions in terms of the KdV-type solitons, possess also an alternative set of multi-soliton solutions which include localized static structures that behave like (static) solitons when they collide with moving solitons. The alternative sets of solutions include the steady-state solution describing the static soliton itself and unsteady solutions describing mutual interactions in a system consisting of a static soliton and several moving solitons. As distinct from common multisoliton solutions those solutions represent combinations of algebraic and hyperbolic functions and cannot be obtained using the traditional methods of soliton theory.
Song, Yuelin; Song, Qingqing; Li, Jun; Zheng, Jiao; Li, Chun; Zhang, Yuan; Zhang, Lingling; Jiang, Yong; Tu, Pengfei
2016-07-01
Direct analysis is of great importance to understand the real chemical profile of a given sample, notably biological materials, because either chemical degradation or diverse errors and uncertainties might be resulted from sophisticated protocols. In comparison with biofluids, it is still challenging for direct analysis of solid biological samples using high performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Herein, a new analytical platform was configured by online hyphenating pressurized liquid extraction (PLE), turbulent flow chromatography (TFC), and LC-MS/MS. A facile, but robust PLE module was constructed based on the phenomenon that noticeable back-pressure can be generated during rapid fluid passing through a narrow tube. TFC column that is advantageous at extracting low molecular analytes from rushing fluid was employed to link at the outlet of the PLE module to capture constituents-of-interest. An electronic 6-port/2-position valve was introduced between TFC column and LC-MS/MS to fragment each measurement into extraction and elution phases, whereas LC-MS/MS took the charge of analyte separation and monitoring. As a proof of concept, simultaneous determination of 24 endogenous substances including eighteen steroids, five eicosanoids, and one porphyrin in feces was carried out in this paper. Method validation assays demonstrated the analytical platform to be qualified for directly simultaneous measurement of diverse endogenous analytes in fecal matrices. Application of this integrated platform on homolog-focused profiling of feces is discussed in a companion paper. PMID:27268518
Sasaki, Akira; Kojo, Masashi; Hirose, Kikuji; Goto, Hidekazu
2011-11-01
The path-integral renormalization group and direct energy minimization method of practical first-principles electronic structure calculations for multi-body systems within the framework of the real-space finite-difference scheme are introduced. These two methods can handle higher dimensional systems with consideration of the correlation effect. Furthermore, they can be easily extended to the multicomponent quantum systems which contain more than two kinds of quantum particles. The key to the present methods is employing linear combinations of nonorthogonal Slater determinants (SDs) as multi-body wavefunctions. As one of the noticeable results, the same accuracy as the variational Monte Carlo method is achieved with a few SDs. This enables us to study the entire ground state consisting of electrons and nuclei without the need to use the Born-Oppenheimer approximation. Recent activities on methodological developments aiming towards practical calculations such as the implementation of auxiliary field for Coulombic interaction, the treatment of the kinetic operator in imaginary-time evolutions, the time-saving double-grid technique for bare-Coulomb atomic potentials and the optimization scheme for minimizing the total-energy functional are also introduced. As test examples, the total energy of the hydrogen molecule, the atomic configuration of the methylene and the electronic structures of two-dimensional quantum dots are calculated, and the accuracy, availability and possibility of the present methods are demonstrated.
NASA Astrophysics Data System (ADS)
Piao, Yongri; Zhang, Miao; Kim, Eun-Soo
2012-02-01
In this paper, we propose an effective approach for resolution-enhanced magnification of a far three-dimensional (3D) object image by employing the moving-direct-pixel-mapping (MDPM) method in the scalable integral imaging system. In the proposed method, a set of elemental image arrays (EIAs) are picked up from a far 3D object with the moving-array-lenslet technique (MALT) and computationally transformed into a new set of EIAs by using the MDPM method, which looks like the EIAs virtually picked up from a close object. These newly transformed EIAs then are interlaced together to form an enlarged EIA, from which resolution-enhanced magnification of a far 3D object image can be achieved. Good experimental results confirm the feasibility of the proposed method.
ERIC Educational Resources Information Center
Cliff, William H.; Curtin, Leslie Nesbitt
2000-01-01
Provides an example of a directed case on human anatomy and physiology. Uses brief real life newspaper articles and clinical descriptions of medical reference texts to describe an actual, fictitious, or composite event. Includes interrelated human anatomy and physiology topics in the scenario. (YDS)
Ding, Wen-jie; Chen, Wen-he; Deng, Ming-jia; Luo, Hui; Li, Lin; Liu, Jun-xin
2016-02-15
Co-processing of sewage sludge using the cement kiln can realize sludge harmless treatment, quantity reduction, stabilization and reutilization. The moisture content should be reduced to below 30% to meet the requirement of combustion. Thermal drying is an effective way for sludge desiccation. Odors and volatile organic compounds are generated and released during the sludge drying process, which could lead to odor pollution. The main odor pollutants were selected by the multi-index integrated assessment method. The concentration, olfactory threshold, threshold limit value, smell security level and saturated vapor pressure were considered as indexes based on the related regulations in China and foreign countries. Taking the pollution potential as the evaluation target, and the risk index and odor emission intensity as evaluation indexes, the odor pollution potential rated evaluation model of the pollutants was built according to the Weber-Fechner law. The aim of the present study is to form the rating evaluation method of odor potential pollution capacity suitable for the directly drying process of sludge. PMID:27363173
Ding, Wen-jie; Chen, Wen-he; Deng, Ming-jia; Luo, Hui; Li, Lin; Liu, Jun-xin
2016-02-15
Co-processing of sewage sludge using the cement kiln can realize sludge harmless treatment, quantity reduction, stabilization and reutilization. The moisture content should be reduced to below 30% to meet the requirement of combustion. Thermal drying is an effective way for sludge desiccation. Odors and volatile organic compounds are generated and released during the sludge drying process, which could lead to odor pollution. The main odor pollutants were selected by the multi-index integrated assessment method. The concentration, olfactory threshold, threshold limit value, smell security level and saturated vapor pressure were considered as indexes based on the related regulations in China and foreign countries. Taking the pollution potential as the evaluation target, and the risk index and odor emission intensity as evaluation indexes, the odor pollution potential rated evaluation model of the pollutants was built according to the Weber-Fechner law. The aim of the present study is to form the rating evaluation method of odor potential pollution capacity suitable for the directly drying process of sludge.
Integrated-optical directional coupler biosensor
NASA Astrophysics Data System (ADS)
Luff, B. J.; Harris, R. D.; Wilkinson, J. S.; Wilson, R.; Schiffrin, D. J.
1996-04-01
We present measurements of biomolecular binding reactions, using a new type of integrated-optical biosensor based on a planar directional coupler structure. The device is fabricated by Ag+ - Na+ ion exchange in glass, and definition of the sensing region is achieved by use of transparent fluoropolymer isolation layers formed by thermal evaporation. The suitability of the sensor for application to the detection of environmental pollutants is considered.
Method for directional hydraulic fracturing
Swanson, David E.; Daly, Daniel W.
1994-01-01
A method for directional hydraulic fracturing using borehole seals to confine pressurized fluid in planar permeable regions, comprising: placing a sealant in the hole of a structure selected from geologic or cemented formations to fill the space between a permeable planar component and the geologic or cemented formation in the vicinity of the permeable planar component; making a hydraulic connection between the permeable planar component and a pump; permitting the sealant to cure and thereby provide both mechanical and hydraulic confinement to the permeable planar component; and pumping a fluid from the pump into the permeable planar component to internally pressurize the permeable planar component to initiate a fracture in the formation, the fracture being disposed in the same orientation as the permeable planar component.
Investigation of direct integrated optics modulators
NASA Technical Reports Server (NTRS)
Batchman, T. E.; Mcwright, G. M.
1981-01-01
Direct optical modulation techniques applicable to integrated optical data preprocessors were studied. Emphasis was placed on the analysis and fabrication of a field effect type modulator. A series of computer modeling studies were performed to determine the effects of semiconductor cladding on the fields of propagating waves in planar dielectric waveguides. These studies predicted that changes in the propagation characteristics of waveguides clad with silicon and gallium arsenide could be made large enough to be useful in modulators. These effects are dependent on the complex permittivity and thickness of the cladding. Since the conductivity of the cladding can be changed by the photon generation of hole-electron pairs, incoherent light may be used as the input to modulate a coherent light beam. Waveguides were fabricated and silicon claddings were applied to verify the theoretical predictions.
Hybrid manufacturing : integrating direct write and sterolithography.
Davis, Donald W.; Inamdar, Asim; Lopes, Amit; Chavez, Bart D.; Gallegos, Phillip L.; Palmer, Jeremy Andrew; Wicker, Ryan B.; Medina, Francisco; Hennessey, Robert E.
2005-07-01
A commercial stereolithography (SL) machine was modified to integrate fluid dispensing or direct-write (DW) technology with SL in an integrated manufacturing environment for automated and efficient hybrid manufacturing of complex electrical devices, combining three-dimensional (3D) electrical circuitry with SL-manufactured parts. The modified SL system operates similarly to a commercially available machine, although build interrupts were used to stop and start the SL build while depositing fluid using the DW system. An additional linear encoder was attached to the SL platform z-stage and used to maintain accurate part registration during the SL and DW build processes. Individual STL files were required as part of the manufacturing process plan. The DW system employed a three-axis translation mechanism that was integrated with the commercial SL machine. Registration between the SL part, SL laser and the DW nozzle was maintained through the use of 0.025-inch diameter cylindrical reference holes manufactured in the part during SL. After depositing conductive ink using DW, the SL laser was commanded to trace the profile until the ink was cured. The current system allows for easy exchange between SL and DW in order to manufacture fully functional 3D electrical circuits and structures in a semi-automated environment. To demonstrate the manufacturing capabilities, the hybrid SL/DW setup was used to make a simple multi-layer SL part with embedded circuitry. This hybrid system is not intended to function as a commercial system, it is intended for experimental demonstration only. This hybrid SL/DW system has the potential for manufacturing fully functional electromechanical devices that are more compact, less expensive, and more reliable than their conventional predecessors, and work is ongoing in order to fully automate the current system.
Directional microwave applicator and methods
NASA Technical Reports Server (NTRS)
Fink, Patrick W. (Inventor); Lin, Greg Y. (Inventor); Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Arndt, G. Dickey (Inventor); Ngo, Phong H. (Inventor)
2008-01-01
A miniature microwave antenna is disclosed which may be utilized for biomedical applications such as, for example, radiation induced hyperthermia through catheter systems. One feature of the antenna is that it possesses azimuthal directionality despite its small size. This directionality permits targeting of certain tissues while limiting thermal exposure of adjacent tissue. One embodiment has an outer diameter of about 0.095'' (2.4 mm) but the design permits for smaller diameters.
Direct Extraction of One-loop Integral Coefficients
Forde, Darren
2007-04-16
We present a general procedure for obtaining the coefficients of the scalar bubble and triangle integral functions of one-loop amplitudes. Coefficients are extracted by considering two-particle and triple unitarity cuts of the corresponding bubble and triangle integral functions. After choosing a specific parameterization of the cut loop momentum we can uniquely identify the coefficients of the desired integral functions simply by examining the behavior of the cut integrand as the unconstrained parameters of the cut loop momentum approach infinity. In this way we can produce compact forms for scalar integral coefficients. Applications of this method are presented for both QCD and electroweak processes, including an alternative form for the recently computed three-mass triangle coefficient in the six-photon amplitude A{sub 6}(1{sup -}, 2{sup +}, 3{sup -}, 4{sup +}, 5{sup -}, 6{sup +}). The direct nature of this extraction procedure allows for a very straightforward automation of the procedure.
Perturbative Methods in Path Integration
NASA Astrophysics Data System (ADS)
Johnson-Freyd, Theodore Paul
This dissertation addresses a number of related questions concerning perturbative "path" integrals. Perturbative methods are one of the few successful ways physicists have worked with (or even defined) these infinite-dimensional integrals, and it is important as mathematicians to check that they are correct. Chapter 0 provides a detailed introduction. We take a classical approach to path integrals in Chapter 1. Following standard arguments, we posit a Feynman-diagrammatic description of the asymptotics of the time-evolution operator for the quantum mechanics of a charged particle moving nonrelativistically through a curved manifold under the influence of an external electromagnetic field. We check that our sum of Feynman diagrams has all desired properties: it is coordinate-independent and well-defined without ultraviolet divergences, it satisfies the correct composition law, and it satisfies Schrodinger's equation thought of as a boundary-value problem in PDE. Path integrals in quantum mechanics and elsewhere in quantum field theory are almost always of the shape ∫ f es for some functions f (the "observable") and s (the "action"). In Chapter 2 we step back to analyze integrals of this type more generally. Integration by parts provides algebraic relations between the values of ∫ (-) es for different inputs, which can be packaged into a Batalin--Vilkovisky-type chain complex. Using some simple homological perturbation theory, we study the version of this complex that arises when f and s are taken to be polynomial functions, and power series are banished. We find that in such cases, the entire scheme-theoretic critical locus (complex points included) of s plays an important role, and that one can uniformly (but noncanonically) integrate out in a purely algebraic way the contributions to the integral from all "higher modes," reducing ∫ f es to an integral over the critical locus. This may help explain the presence of analytic continuation in questions like the
NASA Astrophysics Data System (ADS)
Frisch, Michael J.; Head-Gordon, Martin; Pople, John A.
1990-02-01
We present a direct method for evaluating the gradient of the second-order Møller-Plesset (MP2) energy without storing any quartic quantities, such as two-electron repulsion integrals (ERIs), double substitution amplitudes or the two-particle density matrix. For an N-basis-function calculation, N3 memory is required, and the ERIs and their first derivatives are computed up to O (number of occupied orbitals) times, plus additional ERI evaluations to obtain the Hartree-Fock (HF) orbitals and solve the coupled perturbed HF equation. Larger amounts of memory are used to reduce the O evaluations in the MP2 step. The floating point operation count is still proportional to ON4, as in conventional MP2 gradient codes since ERI evaluation is just an N4 step. Illustrative calculations are reported to assess the performance of the algorithm.
Direct optimization method for reentry trajectory design
NASA Astrophysics Data System (ADS)
Jallade, S.; Huber, P.; Potti, J.; Dutruel-Lecohier, G.
The software package called `Reentry and Atmospheric Transfer Trajectory' (RATT) was developed under ESA contract for the design of atmospheric trajectories. It includes four software TOP (Trajectory OPtimization) programs, which optimize reentry and aeroassisted transfer trajectories. 6FD and 3FD (6 and 3 degrees of freedom Flight Dynamic) are devoted to the simulation of the trajectory. SCA (Sensitivity and Covariance Analysis) performs covariance analysis on a given trajectory with respect to different uncertainties and error sources. TOP provides the optimum guidance law of a three degree of freedom reentry of aeroassisted transfer (AAOT) trajectories. Deorbit and reorbit impulses (if necessary) can be taken into account in the optimization. A wide choice of cost function is available to the user such as the integrated heat flux, or the sum of the velocity impulses, or a linear combination of both of them for trajectory and vehicle design. The crossrange and the downrange can be maximized during reentry trajectory. Path constraints are available on the load factor, the heat flux and the dynamic pressure. Results on these proposed options are presented. TOPPHY is the part of the TOP software corresponding to the definition and the computation of the optimization problemphysics. TOPPHY can interface with several optimizes with dynamic solvers: TOPOP and TROPIC using direct collocation methods and PROMIS using direct multiple shooting method. TOPOP was developed in the frame of this contract, it uses Hermite polynomials for the collocation method and the NPSOL optimizer from the NAG library. Both TROPIC and PROMIS were developed by the DLR (Deutsche Forschungsanstalt fuer Luft und Raumfahrt) and use the SLSQP optimizer. For the dynamic equation resolution, TROPIC uses a collocation method with Splines and PROMIS uses a multiple shooting method with finite differences. The three different optimizers including dynamics were tested on the reentry trajectory of the
Retroviral DNA Integration Directed by HIV Integration Protein in Vitro
NASA Astrophysics Data System (ADS)
Bushman, Frederic D.; Fujiwara, Tamio; Craigie, Robert
1990-09-01
Efficient retroviral growth requires integration of a DNA copy of the viral RNA genome into a chromosome of the host. As a first step in analyzing the mechanism of integration of human immunodeficiency virus (HIV) DNA, a cell-free system was established that models the integration reaction. The in vitro system depends on the HIV integration (IN) protein, which was partially purified from insect cells engineered to express IN protein in large quantities. Integration was detected in a biological assay that scores the insertion of a linear DNA containing HIV terminal sequences into a λ DNA target. Some integration products generated in this assay contained five-base pair duplications of the target DNA at the recombination junctions, a characteristic of HIV integration in vivo; the remaining products contained aberrant junctional sequences that may have been produced in a variation of the normal reaction. These results indicate that HIV IN protein is the only viral protein required to insert model HIV DNA sequences into a target DNA in vitro.
Direct oral anticoagulants: integration into clinical practice
Cowell, Richard P W
2014-01-01
The introduction of direct oral anticoagulants (OACs) for the treatment and prevention of thromboembolic disease represents a shift from the traditional vitamin K antagonist-based therapies, which have been the mainstay of treatment for almost 60 years. A challenge for hospital formularies will be to manage the use of direct OACs from hospital to outpatient settings. Three direct OACs—apixaban, dabigatran and rivaroxaban—are widely approved across different indications, with rivaroxaban approved across the widest breadth of indications. A fourth direct OAC, edoxaban, has also completed phase III trials. Implementation of these agents by physicians will require an understanding of the efficacy and safety profile of these drugs, as well as an awareness of renal function, comedication use, patient adherence and compliance. Optimal implementation of direct OACs in the hospital setting will provide improved patient outcomes when compared with traditional anticoagulants and will simplify the treatment and prevention of thromboembolic diseases. PMID:25012514
Investigation of direct integrated optics modulators. [applicable to data preprocessors
NASA Technical Reports Server (NTRS)
Batchman, T. E.
1980-01-01
Direct modulation techniques applicable to integrated optics data preprocessors were investigated. Several methods of modulating a coherent optical beam by interaction with an incoherent beam were studied. It was decided to investigate photon induced conductivity changes in thin semiconductor cladding layers on optical waveguides. Preliminary calculations indicate significant changes can be produced in the phase shift in a propagating wave when the conductivity is changed by ten percent or more. Experimental devices to verify these predicted phase changes and experiments designed to prove the concept are described.
Ethical considerations of integrating spiritual direction into psychotherapy.
Riggs, Billy J
2006-01-01
Integrating spirituality and religion into clinical practice or psychotherapy has become a significant area of interest in the mental health field today. This article focuses more specifically on integrating spiritual direction into psychotherapy, discusses ethical issues involved, and suggests ethical guidelines for the appropriate and helpful use of spiritual direction in the context of psychotherapy and counseling.
Direct-Broadcast Satellites and Cultural Integrity
ERIC Educational Resources Information Center
Pool, Ithiel de Sola
1975-01-01
Argues that progress in satellite communications depends upon the assurance that satellites are useful to people in all countries, and that a world television network and a worldwide packet data communication system would help achieve that goal, and asserts that direct-satellite television broadcasting does not represent, at present, an active…
Direct toxicity assessment - Methods, evaluation, interpretation.
Gruiz, Katalin; Fekete-Kertész, Ildikó; Kunglné-Nagy, Zsuzsanna; Hajdu, Csilla; Feigl, Viktória; Vaszita, Emese; Molnár, Mónika
2016-09-01
Direct toxicity assessment (DTA) results provide the scale of the actual adverse effect of contaminated environmental samples. DTA results are used in environmental risk management of contaminated water, soil and waste, without explicitly translating the results into chemical concentration. The end points are the same as in environmental toxicology in general, i.e. inhibition rate, decrease in the growth rate or in yield and the 'no effect' or the 'lowest effect' measurement points of the sample dilution-response curve. The measurement unit cannot be a concentration, since the contaminants and their content in the sample is unknown. Thus toxicity is expressed as the sample proportion causing a certain scale of inhibition or no inhibition. Another option for characterizing the scale of toxicity of an environmental sample is equivalencing. Toxicity equivalencing represents an interpretation tool which enables toxicity of unknown mixtures of chemicals be converted into the concentration of an equivalently toxic reference substance. Toxicity equivalencing, (i.e. expressing the toxicity of unknown contaminants as the concentration of the reference) makes DTA results better understandable for non-ecotoxicologists and other professionals educated and thinking based on the chemical model. This paper describes and discusses the role, the principles, the methodology and the interpretation of direct toxicity assessment (DTA) with the aim to contribute to the understanding of the necessity to integrate DTA results into environmental management of contaminated soil and water. The paper also introduces the benefits of the toxicity equivalency method. The use of DTA is illustrated through two case studies. The first case study focuses on DTA of treated wastewater with the aim to characterize the treatment efficacy of a biological wastewater treatment plant by frequent bioassaying. The second case study applied DTA to investigate the cover layers of two bauxite residue (red mud
Direct toxicity assessment - Methods, evaluation, interpretation.
Gruiz, Katalin; Fekete-Kertész, Ildikó; Kunglné-Nagy, Zsuzsanna; Hajdu, Csilla; Feigl, Viktória; Vaszita, Emese; Molnár, Mónika
2016-09-01
Direct toxicity assessment (DTA) results provide the scale of the actual adverse effect of contaminated environmental samples. DTA results are used in environmental risk management of contaminated water, soil and waste, without explicitly translating the results into chemical concentration. The end points are the same as in environmental toxicology in general, i.e. inhibition rate, decrease in the growth rate or in yield and the 'no effect' or the 'lowest effect' measurement points of the sample dilution-response curve. The measurement unit cannot be a concentration, since the contaminants and their content in the sample is unknown. Thus toxicity is expressed as the sample proportion causing a certain scale of inhibition or no inhibition. Another option for characterizing the scale of toxicity of an environmental sample is equivalencing. Toxicity equivalencing represents an interpretation tool which enables toxicity of unknown mixtures of chemicals be converted into the concentration of an equivalently toxic reference substance. Toxicity equivalencing, (i.e. expressing the toxicity of unknown contaminants as the concentration of the reference) makes DTA results better understandable for non-ecotoxicologists and other professionals educated and thinking based on the chemical model. This paper describes and discusses the role, the principles, the methodology and the interpretation of direct toxicity assessment (DTA) with the aim to contribute to the understanding of the necessity to integrate DTA results into environmental management of contaminated soil and water. The paper also introduces the benefits of the toxicity equivalency method. The use of DTA is illustrated through two case studies. The first case study focuses on DTA of treated wastewater with the aim to characterize the treatment efficacy of a biological wastewater treatment plant by frequent bioassaying. The second case study applied DTA to investigate the cover layers of two bauxite residue (red mud
Enhancing Scalability of Sparse Direct Methods
Li, Xiaoye S.; Demmel, James; Grigori, Laura; Gu, Ming; Xia,Jianlin; Jardin, Steve; Sovinec, Carl; Lee, Lie-Quan
2007-07-23
TOPS is providing high-performance, scalable sparse direct solvers, which have had significant impacts on the SciDAC applications, including fusion simulation (CEMM), accelerator modeling (COMPASS), as well as many other mission-critical applications in DOE and elsewhere. Our recent developments have been focusing on new techniques to overcome scalability bottleneck of direct methods, in both time and memory. These include parallelizing symbolic analysis phase and developing linear-complexity sparse factorization methods. The new techniques will make sparse direct methods more widely usable in large 3D simulations on highly-parallel petascale computers.
Methods of conditioning direct methanol fuel cells
Rice, Cynthia; Ren, Xiaoming; Gottesfeld, Shimshon
2005-11-08
Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell ("DMFC") are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer electrolyte membrane of the membrane electrode assembly to a cathode surface of the membrane electrode assembly, and an electrical current of polarity opposite to that in a functioning direct methanol fuel cell is drawn through the membrane electrode assembly, wherein methanol is oxidized at the cathode surface of the membrane electrode assembly while the catalyst on the anode surface is reduced. Surface oxides on the direct methanol fuel cell anode catalyst of the membrane electrode assembly are thereby reduced.
Integrated Force Method for Indeterminate Structures
NASA Technical Reports Server (NTRS)
Hopkins, Dale A.; Halford, Gary R.; Patnaik, Surya N.
2008-01-01
Two methods of solving indeterminate structural-mechanics problems have been developed as products of research on the theory of strain compatibility. In these methods, stresses are considered to be the primary unknowns (in contrast to strains and displacements being considered as the primary unknowns in some prior methods). One of these methods, denoted the integrated force method (IFM), makes it possible to compute stresses, strains, and displacements with high fidelity by use of modest finite-element models that entail relatively small amounts of computation. The other method, denoted the completed Beltrami Mitchell formulation (CBMF), enables direct determination of stresses in an elastic continuum with general boundary conditions, without the need to first calculate displacements as in traditional methods. The equilibrium equation, the compatibility condition, and the material law are the three fundamental concepts of the theory of structures. For almost 150 years, it has been commonly supposed that the theory is complete. However, until now, the understanding of the compatibility condition remained incomplete, and the compatibility condition was confused with the continuity condition. Furthermore, the compatibility condition as applied to structures in its previous incomplete form was inconsistent with the strain formulation in elasticity.
Integrated Aeroservoelastic Optimization: Status and Direction
NASA Technical Reports Server (NTRS)
Livne, Eli
1999-01-01
The interactions of lightweight flexible airframe structures, steady and unsteady aerodynamics, and wide-bandwidth active controls on modern airplanes lead to considerable multidisciplinary design challenges. More than 25 years of mathematical and numerical methods' development, numerous basic research studies, simulations and wind-tunnel tests of simple models, wind-tunnel tests of complex models of real airplanes, as well as flight tests of actively controlled airplanes, have all contributed to the accumulation of a substantial body of knowledge in the area of aeroservoelasticity. A number of analysis codes, with the capabilities to model real airplane systems under the assumptions of linearity, have been developed. Many tests have been conducted, and results were correlated with analytical predictions. A selective sample of references covering aeroservoelastic testing programs from the 1960s to the early 1980s, as well as more recent wind-tunnel test programs of real or realistic configurations, are included in the References section of this paper. An examination of references 20-29 will reveal that in the course of development (or later modification), of almost every modern airplane with a high authority active control system, there arose a need to face aeroservoelastic problems and aeroservoelastic design challenges.
Method of descent for integrable lattices
NASA Astrophysics Data System (ADS)
Bogoyavlensky, Oleg
2009-05-01
A method of descent for constructing integrable Hamiltonian systems is introduced. The derived periodic and nonperiodic lattices possess Lax representations with spectral parameter and have plenty of first integrals. Examples of Liouville-integrable four-dimensional Hamiltonian Lotka-Volterra systems are presented.
Integrated Methods: Applications in Quantum Chemistry
Irle, Stephen; Morokuma, Keiji
2004-03-31
Authors introduce quantum chemical methods applicable to extended molecular systems or parts of them, describe in short the theory behind integrated methods, and discuss their applications to the most recognizable areas of nanochemistry (fullerenes, nanotubes, and silica- based nanosystems).
Integrated control system and method
Wang, Paul Sai Keat; Baldwin, Darryl; Kim, Myoungjin
2013-10-29
An integrated control system for use with an engine connected to a generator providing electrical power to a switchgear is disclosed. The engine receives gas produced by a gasifier. The control system includes an electronic controller associated with the gasifier, engine, generator, and switchgear. A gas flow sensor monitors a gas flow from the gasifier to the engine through an engine gas control valve and provides a gas flow signal to the electronic controller. A gas oversupply sensor monitors a gas oversupply from the gasifier and provides an oversupply signal indicative of gas not provided to the engine. A power output sensor monitors a power output of the switchgear and provide a power output signal. The electronic controller changes gas production of the gasifier and the power output rating of the switchgear based on the gas flow signal, the oversupply signal, and the power output signal.
Fast integral methods for integrated optical systems simulations: a review
NASA Astrophysics Data System (ADS)
Kleemann, Bernd H.
2015-09-01
Boundary integral equation methods (BIM) or simply integral methods (IM) in the context of optical design and simulation are rigorous electromagnetic methods solving Helmholtz or Maxwell equations on the boundary (surface or interface of the structures between two materials) for scattering or/and diffraction purposes. This work is mainly restricted to integral methods for diffracting structures such as gratings, kinoforms, diffractive optical elements (DOEs), micro Fresnel lenses, computer generated holograms (CGHs), holographic or digital phase holograms, periodic lithographic structures, and the like. In most cases all of the mentioned structures have dimensions of thousands of wavelengths in diameter. Therefore, the basic methods necessary for the numerical treatment are locally applied electromagnetic grating diffraction algorithms. Interestingly, integral methods belong to the first electromagnetic methods investigated for grating diffraction. The development started in the mid 1960ies for gratings with infinite conductivity and it was mainly due to the good convergence of the integral methods especially for TM polarization. The first integral equation methods (IEM) for finite conductivity were the methods by D. Maystre at Fresnel Institute in Marseille: in 1972/74 for dielectric, and metallic gratings, and later for multiprofile, and other types of gratings and for photonic crystals. Other methods such as differential and modal methods suffered from unstable behaviour and slow convergence compared to BIMs for metallic gratings in TM polarization from the beginning to the mid 1990ies. The first BIM for gratings using a parametrization of the profile was developed at Karl-Weierstrass Institute in Berlin under a contract with Carl Zeiss Jena works in 1984-1986 by A. Pomp, J. Creutziger, and the author. Due to the parametrization, this method was able to deal with any kind of surface grating from the beginning: whether profiles with edges, overhanging non
Methods for direct alkene diamination, new & old
de Jong, Sam; Nosal, Daniel G.; Wardrop, Duncan J.
2012-01-01
The 1,2-diamine moiety is a ubiquitous structural motif present in a wealth of natural products, including non-proteinogenic amino acids and numerous alkaloids, as well as in pharmaceutical agents, chiral ligands and organic reagents. The biological activity associated with many of these systems and their chemical utility in general has ensured that the development of methods for their preparation is of critical importance. While a wide range of strategies for the preparation of 1,2-diamines have been established, the diamination of alkenes offers a particularly direct and efficient means of accessing these systems. The purpose of this review is to provide an overview of all methods of direct alkene diamination, metal-mediated or otherwise. PMID:22888177
Efficient orbit integration by manifold correction methods.
Fukushima, Toshio
2005-12-01
Triggered by a desire to investigate, numerically, the planetary precession through a long-term numerical integration of the solar system, we developed a new formulation of numerical integration of orbital motion named manifold correct on methods. The main trick is to rigorously retain the consistency of physical relations, such as the orbital energy, the orbital angular momentum, or the Laplace integral, of a binary subsystem. This maintenance is done by applying a correction to the integrated variables at each integration step. Typical methods of correction are certain geometric transformations, such as spatial scaling and spatial rotation, which are commonly used in the comparison of reference frames, or mathematically reasonable operations, such as modularization of angle variables into the standard domain [-pi, pi). The form of the manifold correction methods finally evolved are the orbital longitude methods, which enable us to conduct an extremely precise integration of orbital motions. In unperturbed orbits, the integration errors are suppressed at the machine epsilon level for an indefinitely long period. In perturbed cases, on the other hand, the errors initially grow in proportion to the square root of time and then increase more rapidly, the onset of which depends on the type and magnitude of the perturbations. This feature is also realized for highly eccentric orbits by applying the same idea as used in KS-regularization. In particular, the introduction of time elements greatly enhances the performance of numerical integration of KS-regularized orbits, whether the scaling is applied or not.
Non-contact method for directing electrotaxis
NASA Astrophysics Data System (ADS)
Ahirwar, Dinesh K.; Nasser, Mohd W.; Jones, Travis H.; Sequin, Emily K.; West, Joseph D.; Henthorne, Timothy L.; Javor, Joshua; Kaushik, Aniruddha M.; Ganju, Ramesh K.; Subramaniam, Vish V.
2015-06-01
We present a method to induce electric fields and drive electrotaxis (galvanotaxis) without the need for electrodes to be in contact with the media containing the cell cultures. We report experimental results using a modification of the transmembrane assay, demonstrating the hindrance of migration of breast cancer cells (SCP2) when an induced a.c. electric field is present in the appropriate direction (i.e. in the direction of migration). Of significance is that migration of these cells is hindered at electric field strengths many orders of magnitude (5 to 6) below those previously reported for d.c. electrotaxis, and even in the presence of a chemokine (SDF-1α) or a growth factor (EGF). Induced a.c. electric fields applied in the direction of migration are also shown to hinder motility of non-transformed human mammary epithelial cells (MCF10A) in the presence of the growth factor EGF. In addition, we also show how our method can be applied to other cell migration assays (scratch assay), and by changing the coil design and holder, that it is also compatible with commercially available multi-well culture plates.
Non-contact method for directing electrotaxis
Ahirwar, Dinesh K.; Nasser, Mohd W.; Jones, Travis H.; Sequin, Emily K.; West, Joseph D.; Henthorne, Timothy L.; Javor, Joshua; Kaushik, Aniruddha M.; Ganju, Ramesh K.; Subramaniam, Vish V.
2015-01-01
We present a method to induce electric fields and drive electrotaxis (galvanotaxis) without the need for electrodes to be in contact with the media containing the cell cultures. We report experimental results using a modification of the transmembrane assay, demonstrating the hindrance of migration of breast cancer cells (SCP2) when an induced a.c. electric field is present in the appropriate direction (i.e. in the direction of migration). Of significance is that migration of these cells is hindered at electric field strengths many orders of magnitude (5 to 6) below those previously reported for d.c. electrotaxis, and even in the presence of a chemokine (SDF-1α) or a growth factor (EGF). Induced a.c. electric fields applied in the direction of migration are also shown to hinder motility of non-transformed human mammary epithelial cells (MCF10A) in the presence of the growth factor EGF. In addition, we also show how our method can be applied to other cell migration assays (scratch assay), and by changing the coil design and holder, that it is also compatible with commercially available multi-well culture plates. PMID:26055698
Helping Abused and Traumatized Children: Integrating Directive and Nondirective Approaches
ERIC Educational Resources Information Center
Gil, Eliana
2006-01-01
Presenting an integrative model for treating traumatized children, this book combines play, art, and other expressive therapies with ideas and strategies drawn from cognitive-behavioral and family therapy. Eliana Gil demonstrates how to tailor treatment to the needs of each child by using both directive and nondirective approaches. Throughout,…
Direct Instruction vs. Arts Integration: A False Dichotomy
ERIC Educational Resources Information Center
Aprill, Arnold
2010-01-01
In this article, the author takes on what he considers to be the false dichotomy between direct instruction and arts integration. He contends that at a time when national issues of sustainability and conservation of energy and resources become ever more urgent, it is time that those committed to quality arts education stop squandering time, money,…
EMERGY METHODS: VALUABLE INTEGRATED ASSESSMENT TOOLS
NHEERL's Atlantic Ecology Division is investigating emergy methods as tools for integrated assessment in several projects evaluating environmental impacts, policies, and alternatives for remediation and intervention. Emergy accounting is a methodology that provides a quantitative...
Direct volume rendering methods for cell structures.
Martišek, Dalibor; Martišek, Karel
2012-01-01
The study of the complicated architecture of cell space structures is an important problem in biology and medical research. Optical cuts of cells produced by confocal microscopes enable two-dimensional (2D) and three-dimensional (3D) reconstructions of observed cells. This paper discuses new possibilities for direct volume rendering of these data. We often encounter 16 or more bit images in confocal microscopy of cells. Most of the information contained in these images is unsubstantial for the human vision. Therefore, it is necessary to use mathematical algorithms for visualization of such images. Present software tools as OpenGL or DirectX run quickly in graphic station with special graphic cards, run very unsatisfactory on PC without these cards and outputs are usually poor for real data. These tools are black boxes for a common user and make it impossible to correct and improve them. With the method proposed, more parameters of the environment can be set, making it possible to apply 3D filters to set the output image sharpness in relation to the noise. The quality of the output is incomparable to the earlier described methods and is worth increasing the computing time. We would like to offer mathematical methods of 3D scalar data visualization describing new algorithms that run on standard PCs very well. PMID:22511504
Efficient orbit integration by orbital longitude methods
NASA Astrophysics Data System (ADS)
Fukushima, Toshio
Recently we developed a new formulation of numerical integration of orbital motion named manifold correction methods. The main trick is to keep rigorously the consistency of some physical relations such as that of the orbital energy, of the orbital angular momentum, or of the Laplace integral of a binary subsystem. This maintenance is done by applying a sort of correction to the integrated variables at every integration step. Typical methods of correction are certain geometric transformation such as the spatial scaling and the spatial rotation, which are commonly used in the comparison of reference frames, or mathematically-reasonable operations such as the modularization of angle variables into the standard domain [-π, π). The finally-evolved form of the manifold correction methods is the orbital longitude methods, which enable us to conduct an extremely precise integration of orbital motions. In the unperturbed orbits, the integration errors are suppressed at the machine epsilon level for an infinitely long period. In the perturbed cases, on the other hand, the errors initially grow in proportion to the square root of time and then increase more rapidly, the onset time of which depends on the type and the magnitude of perturbations. This feature is also realized for highly eccentric orbits by applying the same idea to the KS-regularization. Expecially the introduction of time element greatly enhances the performance of numerical integration of KS-regularized orbits whether the scaling is applied or not.
NASA Astrophysics Data System (ADS)
Liu, Xiaofeng; Siddle-Mitchell, Seth
2015-11-01
This paper presents a novel pressure reconstruction method featuring rotating parallel ray omni-directional integration, as an improvement over the circular virtual boundary integration method introduced by Liu and Katz (2003, 2006, 2008 and 2013) for non-intrusive instantaneous pressure measurement in incompressible flow field. Unlike the virtual boundary omni-directional integration, where the integration path is originated from a virtual circular boundary at a finite distance from the real boundary of the integration domain, the new method utilizes parallel rays, which can be viewed as being originated from a distance of infinity, as guidance for integration paths. By rotating the parallel rays, omni-directional paths with equal weights coming from all directions toward the point of interest at any location within the computation domain will be generated. In this way, the location dependence of the integration weight inherent in the old algorithm will be eliminated. By implementing this new algorithm, the accuracy of the reconstructed pressure for a synthetic rotational flow in terms of r.m.s. error from theoretical values is reduced from 1.03% to 0.30%. Improvement is further demonstrated from the comparison of the reconstructed pressure with that from the Johns Hopkins University isotropic turbulence database (JHTDB). This project is funded by the San Diego State University.
EDM 1.0: electron direct methods.
Kilaas, R; Marks, L D; Own, C S
2005-02-01
A computer program designed to provide a number of quantitative analysis tools for high-resolution imaging and electron diffraction data is described. The program includes basic image manipulation, both real space and reciprocal space image processing, Wiener-filtering, symmetry averaging, methods for quantification of electron diffraction patterns and two-dimensional direct methods. The program consists of a number of sub-programs written in a combination of C++, C and Fortran. It can be downloaded either as GNU source code or as binaries and has been compiled and verified on a wide range of platforms, both Unix based and PC's. Elements of the design philosophy as well as future possible extensions are described.
The present state and future directions of PDF methods
NASA Technical Reports Server (NTRS)
Pope, S. B.
1992-01-01
The objectives of the workshop are presented in viewgraph format, as is this entire article. The objectives are to discuss the present status and the future direction of various levels of engineering turbulence modeling related to Computational Fluid Dynamics (CFD) computations for propulsion; to assure that combustion is an essential part of propulsion; and to discuss Probability Density Function (PDF) methods for turbulent combustion. Essential to the integration of turbulent combustion models is the development of turbulent model, chemical kinetics, and numerical method. Some turbulent combustion models typically used in industry are the k-epsilon turbulent model, the equilibrium/mixing limited combustion, and the finite volume codes.
Efficient orbit integration by orbital longitude methods
NASA Astrophysics Data System (ADS)
Fukushima, T.
2005-09-01
Triggered by the desire to investigate numerically the planetary precession through a long-term numerical integration of the solar system, we developed a new formulation of numerical integration of orbital motion named manifold correction methods. The main trick is to keep rigorously the consistency of some physical relations such as that of the orbital energy, of the orbital angular momentum, or of the Laplace integral of a binary subsystem. This maintenance is done by applying a sort of correction to the integrated variables at every integration step. Typical methods of correction are certain geometric transformation such as the spatial scaling and the spatial rotation, which are commonly used in the comparison of reference frames, or mathematically-reasonable operations such as the modularization of angle variables into the standard domain [-π,π). The finally-evolved form of the manifold correction methods is the orbital longitude methods, which enable us to conduct an extremely precise integration of orbital motions. In the unperturbed orbits, the integration errors are suppressed at the machine epsilon level for an infinitely long period. In the perturbed cases, on the other hand, the errors initially grow in proportion to the square root of time and then increase more rapidly, the onset time of which depends on the type and the magnitude of perturbations. This feature is also realized for highly eccentric orbits by applying the same idea to the KS-regularization. Especially the introduction of time element greatly enhances the performance of numerical integration of KS-regularized orbits whether the scaling is applied or not.
Efficient integration method for fictitious domain approaches
NASA Astrophysics Data System (ADS)
Duczek, Sascha; Gabbert, Ulrich
2015-10-01
In the current article, we present an efficient and accurate numerical method for the integration of the system matrices in fictitious domain approaches such as the finite cell method (FCM). In the framework of the FCM, the physical domain is embedded in a geometrically larger domain of simple shape which is discretized using a regular Cartesian grid of cells. Therefore, a spacetree-based adaptive quadrature technique is normally deployed to resolve the geometry of the structure. Depending on the complexity of the structure under investigation this method accounts for most of the computational effort. To reduce the computational costs for computing the system matrices an efficient quadrature scheme based on the divergence theorem (Gauß-Ostrogradsky theorem) is proposed. Using this theorem the dimension of the integral is reduced by one, i.e. instead of solving the integral for the whole domain only its contour needs to be considered. In the current paper, we present the general principles of the integration method and its implementation. The results to several two-dimensional benchmark problems highlight its properties. The efficiency of the proposed method is compared to conventional spacetree-based integration techniques.
Direct path integral estimators for isotope fractionation ratios
Cheng, Bingqing; Ceriotti, Michele
2014-12-28
Fractionation of isotopes among distinct molecules or phases is a quantum effect which is often exploited to obtain insights on reaction mechanisms, biochemical, geochemical, and atmospheric phenomena. Accurate evaluation of isotope ratios in atomistic simulations is challenging, because one needs to perform a thermodynamic integration with respect to the isotope mass, along with time-consuming path integral calculations. By re-formulating the problem as a particle exchange in the ring polymer partition function, we derive new estimators giving direct access to the differential partitioning of isotopes, which can simplify the calculations by avoiding thermodynamic integration. We demonstrate the efficiency of these estimators by applying them to investigate the isotope fractionation ratios in the gas-phase Zundel cation, and in a few simple hydrocarbons.
Direct-write fabrication of integrated, multilayer ceramic components
Dimos, D.; Yang, P.; Garino, T.J.; Raymond, M.V.; Rodriguez, M.A.
1997-08-01
The need for advanced (electronic) ceramic components with smaller size, greater functionality, and enhanced reliability requires the ability to integrate electronic ceramics in complex 3-D architectures. For rapid prototyping and small-lot manufacturing, traditional tape casting and screen printing approaches are poorly suited. To address this need, the authors are developing a direct-write approach for fabricating highly integrated, multilayer components using a micropen to deposit slurries in precise patterns. With this technique, components can be constructed layer by layer, simplifying fabrication. It can also be used to produce structures combining several materials in a single layer. The parts are either cofired or sequentially fired, after each layer is deposited. Since differential shrinkage can lead to defects in these multilayer structures, they are characterizing the sintering behavior of individual layers. This technique has been used to fabricate devices such integrated RC filters, multilayer voltage transformers, and other passive components. The direct-write approach provides the ability to fabricate multifunctional, multimaterial integrated ceramic components (MMICCs) in an agile and rapid way.
Direct ultrafiltration performance and membrane integrity monitoring by microbiological analysis.
Ferrer, O; Casas, S; Galvañ, C; Lucena, F; Bosch, A; Galofré, B; Mesa, J; Jofre, J; Bernat, X
2015-10-15
The feasibility of substituting a conventional pre-treatment, consisting of dioxi-chlorination, coagulation/flocculation, settling and sand filtration, of a drinking water treatment plant (DWTP) by direct ultrafiltration (UF) has been assessed from a microbiological standpoint. Bacterial indicators, viral indicators and human viruses have been monitored in raw river, ultrafiltered and conventionally pre-treated water samples during two years. Direct UF has proven to remove bacterial indicators quite efficiently and to a greater extent than the conventional process does. Nevertheless, the removal of small viruses such as some small bacteriophages and human viruses (e.g. enteroviruses and noroviruses) is lower than the current conventional pre-treatment. Membrane integrity has been assessed during two years by means of tailored tests based on bacteriophages with different properties (MS-2, GA and PDR-1) and bacterial spores (Bacillus spores). Membrane integrity has not been compromised despite the challenging conditions faced by directly treating raw river water. Bacteriophage PDR-1 appears as a suitable microbe to test membrane integrity, as its size is slightly larger than the considered membrane pore size. However, its implementation at full scale plant is still challenging due to difficulties in obtaining enough phages for its seeding.
NASA Astrophysics Data System (ADS)
Xie, Guizhong; Zhang, Dehai; Zhang, Jianming; Meng, Fannian; Du, Wenliao; Wen, Xiaoyu
2016-07-01
As a widely used numerical method, boundary element method (BEM) is efficient for computer aided engineering (CAE). However, boundary integrals with near singularity need to be calculated accurately and efficiently to implement BEM for CAE analysis on thin bodies successfully. In this paper, the distance in the denominator of the fundamental solution is first designed as an equivalent form using approximate expansion and the original sinh method can be revised into a new form considering the minimum distance and the approximate expansion. Second, the acquisition of the projection point by Newton-Raphson method is introduced. We acquire the nearest point between the source point and element edge by solving a cubic equation if the location of the projection point is outside the element, where boundary integrals with near singularity appear. Finally, the subtriangles of the local coordinate space are mapped into the integration space and the sinh method is applied in the integration space. The revised sinh method can be directly performed in the integration element. Averification test of our method is proposed. Results demonstrate that our method is effective for regularizing the boundary integrals with near singularity.
Differential temperature integrating diagnostic method and apparatus
Doss, James D.; McCabe, Charles W.
1976-01-01
A method and device for detecting the presence of breast cancer in women by integrating the temperature difference between the temperature of a normal breast and that of a breast having a malignant tumor. The breast-receiving cups of a brassiere are each provided with thermally conductive material next to the skin, with a thermistor attached to the thermally conductive material in each cup. The thermistors are connected to adjacent arms of a Wheatstone bridge. Unbalance currents in the bridge are integrated with respect to time by means of an electrochemical integrator. In the absence of a tumor, both breasts maintain substantially the same temperature, and the bridge remains balanced. If the tumor is present in one breast, a higher temperature in that breast unbalances the bridge and the electrochemical cells integrate the temperature difference with respect to time.
Integrated force method versus displacement method for finite element analysis
NASA Technical Reports Server (NTRS)
Patnaik, Surya N.; Berke, Laszlo; Gallagher, Richard H.
1990-01-01
A novel formulation termed the integrated force method (IFM) has been developed in recent years for analyzing structures. In this method all the internal forces are taken as independent variables, and the system equilibrium equations (EE's) are integrated with the global compatibility conditions (CC's) to form the governing set of equations. In IFM the CC's are obtained from the strain formulation of St. Venant, and no choices of redundant load systems have to be made, in constrast to the standard force method (SFM). This property of IFM allows the generation of the governing equation to be automated straightforwardly, as it is in the popular stiffness method (SM). In this report IFM and SM are compared relative to the structure of their respective equations, their conditioning, required solution methods, overall computational requirements, and convergence properties as these factors influence the accuracy of the results. Overall, this new version of the force method produces more accurate results than the stiffness method for comparable computational cost.
Implicit integration methods for dislocation dynamics
Gardner, D. J.; Woodward, C. S.; Reynolds, D. R.; Hommes, G.; Aubry, S.; Arsenlis, A.
2015-01-20
In dislocation dynamics simulations, strain hardening simulations require integrating stiff systems of ordinary differential equations in time with expensive force calculations, discontinuous topological events, and rapidly changing problem size. Current solvers in use often result in small time steps and long simulation times. Faster solvers may help dislocation dynamics simulations accumulate plastic strains at strain rates comparable to experimental observations. Here, this paper investigates the viability of high order implicit time integrators and robust nonlinear solvers to reduce simulation run times while maintaining the accuracy of the computed solution. In particular, implicit Runge-Kutta time integrators are explored as a waymore » of providing greater accuracy over a larger time step than is typically done with the standard second-order trapezoidal method. In addition, both accelerated fixed point and Newton's method are investigated to provide fast and effective solves for the nonlinear systems that must be resolved within each time step. Results show that integrators of third order are the most effective, while accelerated fixed point and Newton's method both improve solver performance over the standard fixed point method used for the solution of the nonlinear systems.« less
Implicit integration methods for dislocation dynamics
Gardner, D. J.; Woodward, C. S.; Reynolds, D. R.; Hommes, G.; Aubry, S.; Arsenlis, A.
2015-01-20
In dislocation dynamics simulations, strain hardening simulations require integrating stiff systems of ordinary differential equations in time with expensive force calculations, discontinuous topological events, and rapidly changing problem size. Current solvers in use often result in small time steps and long simulation times. Faster solvers may help dislocation dynamics simulations accumulate plastic strains at strain rates comparable to experimental observations. Here, this paper investigates the viability of high order implicit time integrators and robust nonlinear solvers to reduce simulation run times while maintaining the accuracy of the computed solution. In particular, implicit Runge-Kutta time integrators are explored as a way of providing greater accuracy over a larger time step than is typically done with the standard second-order trapezoidal method. In addition, both accelerated fixed point and Newton's method are investigated to provide fast and effective solves for the nonlinear systems that must be resolved within each time step. Results show that integrators of third order are the most effective, while accelerated fixed point and Newton's method both improve solver performance over the standard fixed point method used for the solution of the nonlinear systems.
Bioluminescent bioreporter integrated circuit detection methods
Simpson, Michael L.; Paulus, Michael J.; Sayler, Gary S.; Applegate, Bruce M.; Ripp, Steven A.
2005-06-14
Disclosed are monolithic bioelectronic devices comprising a bioreporter and an OASIC. These bioluminescent bioreporter integrated circuit are useful in detecting substances such as pollutants, explosives, and heavy-metals residing in inhospitable areas such as groundwater, industrial process vessels, and battlefields. Also disclosed are methods and apparatus for detection of particular analytes, including ammonia and estrogen compounds.
Fidelity of the Integrated Force Method Solution
NASA Technical Reports Server (NTRS)
Hopkins, Dale; Halford, Gary; Coroneos, Rula; Patnaik, Surya
2002-01-01
The theory of strain compatibility of the solid mechanics discipline was incomplete since St. Venant's 'strain formulation' in 1876. We have addressed the compatibility condition both in the continuum and the discrete system. This has lead to the formulation of the Integrated Force Method. A dual Integrated Force Method with displacement as the primal variable has also been formulated. A modest finite element code (IFM/Analyzers) based on the IFM theory has been developed. For a set of standard test problems the IFM results were compared with the stiffness method solutions and the MSC/Nastran code. For the problems IFM outperformed the existing methods. Superior IFM performance is attributed to simultaneous compliance of equilibrium equation and compatibility condition. MSC/Nastran organization expressed reluctance to accept the high fidelity IFM solutions. This report discusses the solutions to the examples. No inaccuracy was detected in the IFM solutions. A stiffness method code with a small programming effort can be improved to reap the many IFM benefits when implemented with the IFMD elements. Dr. Halford conducted a peer-review on the Integrated Force Method. Reviewers' response is included.
Numerical methods for engine-airframe integration
Murthy, S.N.B.; Paynter, G.C.
1986-01-01
Various papers on numerical methods for engine-airframe integration are presented. The individual topics considered include: scientific computing environment for the 1980s, overview of prediction of complex turbulent flows, numerical solutions of the compressible Navier-Stokes equations, elements of computational engine/airframe integrations, computational requirements for efficient engine installation, application of CAE and CFD techniques to complete tactical missile design, CFD applications to engine/airframe integration, and application of a second-generation low-order panel methods to powerplant installation studies. Also addressed are: three-dimensional flow analysis of turboprop inlet and nacelle configurations, application of computational methods to the design of large turbofan engine nacelles, comparison of full potential and Euler solution algorithms for aeropropulsive flow field computations, subsonic/transonic, supersonic nozzle flows and nozzle integration, subsonic/transonic prediction capabilities for nozzle/afterbody configurations, three-dimensional viscous design methodology of supersonic inlet systems for advanced technology aircraft, and a user's technology assessment.
Package for integrated optic circuit and method
Kravitz, S.H.; Hadley, G.R.; Warren, M.E.; Carson, R.F.; Armendariz, M.G.
1998-08-04
A structure and method are disclosed for packaging an integrated optic circuit. The package comprises a first wall having a plurality of microlenses formed therein to establish channels of optical communication with an integrated optic circuit within the package. A first registration pattern is provided on an inside surface of one of the walls of the package for alignment and attachment of the integrated optic circuit. The package in one embodiment may further comprise a fiber holder for aligning and attaching a plurality of optical fibers to the package and extending the channels of optical communication to the fibers outside the package. In another embodiment, a fiber holder may be used to hold the fibers and align the fibers to the package. The fiber holder may be detachably connected to the package. 6 figs.
Package for integrated optic circuit and method
Kravitz, Stanley H.; Hadley, G. Ronald; Warren, Mial E.; Carson, Richard F.; Armendariz, Marcelino G.
1998-01-01
A structure and method for packaging an integrated optic circuit. The package comprises a first wall having a plurality of microlenses formed therein to establish channels of optical communication with an integrated optic circuit within the package. A first registration pattern is provided on an inside surface of one of the walls of the package for alignment and attachment of the integrated optic circuit. The package in one embodiment may further comprise a fiber holder for aligning and attaching a plurality of optical fibers to the package and extending the channels of optical communication to the fibers outside the package. In another embodiment, a fiber holder may be used to hold the fibers and align the fibers to the package. The fiber holder may be detachably connected to the package.
Integrability: mathematical methods for studying solitary waves theory
NASA Astrophysics Data System (ADS)
Wazwaz, Abdul-Majid
2014-03-01
real features in a variety of vital areas in science, technology and engineering. In recognition of the importance of solitary waves theory and the underlying concept of integrable equations, a variety of powerful methods have been developed to carry out the required analysis. Examples of such methods which have been advanced are the inverse scattering method, the Hirota bilinear method, the simplified Hirota method, the Bäcklund transformation method, the Darboux transformation, the Pfaffian technique, the Painlevé analysis, the generalized symmetry method, the subsidiary ordinary differential equation method, the coupled amplitude-phase formulation, the sine-cosine method, the sech-tanh method, the mapping and deformation approach and many new other methods. The inverse scattering method, viewed as a nonlinear analogue of the Fourier transform method, is a powerful approach that demonstrates the existence of soliton solutions through intensive computations. At the center of the theory of integrable equations lies the bilinear forms and Hirota's direct method, which can be used to obtain soliton solutions by using exponentials. The Bäcklund transformation method is a useful invariant transformation that transforms one solution into another of a differential equation. The Darboux transformation method is a well known tool in the theory of integrable systems. It is believed that there is a connection between the Bäcklund transformation and the Darboux transformation, but it is as yet not known. Archetypes of integrable equations are the Korteweg-de Vries (KdV) equation, the modified KdV equation, the sine-Gordon equation, the Schrödinger equation, the Vakhnenko equation, the KdV6 equation, the Burgers equation, the fifth-order Lax equation and many others. These equations yield soliton solutions, multiple soliton solutions, breather solutions, quasi-periodic solutions, kink solutions, homo-clinic solutions and other solutions as well. The couplings of linear and
Spatial Interpolation Methods for Integrating Newton's Equation
NASA Astrophysics Data System (ADS)
Gueron, Shay; Shalloway, David
1996-11-01
Numerical integration of Newton's equation in multiple dimensions plays an important role in many fields such as biochemistry and astrophysics. Currently, some of the most important practical questions in these areas cannot be addressed because the large dimensionality of the variable space and complexity of the required force evaluations precludes integration over sufficiently large time intervals. Improving the efficiency of algorithms for this purpose is therefore of great importance. Standard numerical integration schemes (e.g., leap-frog and Runge-Kutta) ignore the special structure of Newton's equation that, for conservative systems, constrains the force to be the gradient of a scalar potential. We propose a new class of "spatial interpolation" (SI) integrators that exploit this property by interpolating the force in space rather than (as with standard methods) in time. Since the force is usually a smoother function of space than of time, this can improve algorithmic efficiency and accuracy. In particular, an SI integrator solves the one- and two-dimensional harmonic oscillators exactly with one force evaluation per step. A simple type of time-reversible SI algorithm is described and tested. Significantly improved performance is achieved on one- and multi-dimensional benchmark problems.
Approximation method to compute domain related integrals in structural studies
NASA Astrophysics Data System (ADS)
Oanta, E.; Panait, C.; Raicu, A.; Barhalescu, M.; Axinte, T.
2015-11-01
Various engineering calculi use integral calculus in theoretical models, i.e. analytical and numerical models. For usual problems, integrals have mathematical exact solutions. If the domain of integration is complicated, there may be used several methods to calculate the integral. The first idea is to divide the domain in smaller sub-domains for which there are direct calculus relations, i.e. in strength of materials the bending moment may be computed in some discrete points using the graphical integration of the shear force diagram, which usually has a simple shape. Another example is in mathematics, where the surface of a subgraph may be approximated by a set of rectangles or trapezoids used to calculate the definite integral. The goal of the work is to introduce our studies about the calculus of the integrals in the transverse section domains, computer aided solutions and a generalizing method. The aim of our research is to create general computer based methods to execute the calculi in structural studies. Thus, we define a Boolean algebra which operates with ‘simple’ shape domains. This algebraic standpoint uses addition and subtraction, conditioned by the sign of every ‘simple’ shape (-1 for the shapes to be subtracted). By ‘simple’ shape or ‘basic’ shape we define either shapes for which there are direct calculus relations, or domains for which their frontiers are approximated by known functions and the according calculus is carried out using an algorithm. The ‘basic’ shapes are linked to the calculus of the most significant stresses in the section, refined aspect which needs special attention. Starting from this idea, in the libraries of ‘basic’ shapes, there were included rectangles, ellipses and domains whose frontiers are approximated by spline functions. The domain triangularization methods suggested that another ‘basic’ shape to be considered is the triangle. The subsequent phase was to deduce the exact relations for the
Development of Improved Surface Integral Methods for Jet Aeroacoustic Predictions
NASA Technical Reports Server (NTRS)
Pilon, Anthony R.; Lyrintzis, Anastasios S.
1997-01-01
The accurate prediction of aerodynamically generated noise has become an important goal over the past decade. Aeroacoustics must now be an integral part of the aircraft design process. The direct calculation of aerodynamically generated noise with CFD-like algorithms is plausible. However, large computer time and memory requirements often make these predictions impractical. It is therefore necessary to separate the aeroacoustics problem into two parts, one in which aerodynamic sound sources are determined, and another in which the propagating sound is calculated. This idea is applied in acoustic analogy methods. However, in the acoustic analogy, the determination of far-field sound requires the solution of a volume integral. This volume integration again leads to impractical computer requirements. An alternative to the volume integrations can be found in the Kirchhoff method. In this method, Green's theorem for the linear wave equation is used to determine sound propagation based on quantities on a surface surrounding the source region. The change from volume to surface integrals represents a tremendous savings in the computer resources required for an accurate prediction. This work is concerned with the development of enhancements of the Kirchhoff method for use in a wide variety of aeroacoustics problems. This enhanced method, the modified Kirchhoff method, is shown to be a Green's function solution of Lighthill's equation. It is also shown rigorously to be identical to the methods of Ffowcs Williams and Hawkings. This allows for development of versatile computer codes which can easily alternate between the different Kirchhoff and Ffowcs Williams-Hawkings formulations, using the most appropriate method for the problem at hand. The modified Kirchhoff method is developed primarily for use in jet aeroacoustics predictions. Applications of the method are shown for two dimensional and three dimensional jet flows. Additionally, the enhancements are generalized so that
Cabbages--And Kings: Research Directions in Integrated/Interdisciplinary Curriculum.
ERIC Educational Resources Information Center
Kain, Daniel L.
1993-01-01
Examines past research into integrated or interdisciplinary studies and explores future directions for research. Discusses reasons for integrating curricula, characteristics of integrated studies, benefits of curriculum integration, and pedagogical changes accompanying integrated studies. Predicts an unstable future for integrated studies.…
[General integral medicine: the strategic direction for complex health interventions].
Hou, Zheng-kun; Liu, Feng-bin; Yang, Yun-ying; Chen, Xin-lin; Li, Li-juan; Li, Pei-wu; Liu, Yuan-peng
2014-06-01
Nowadays, the simple combination of Western medicine (WM) and complementary and alternative medicine (CAM) cannot resolve all the health problems and various requirements. This article proposed the general integral medicine (GIM) theoretical model, which declares the disease causes analysis, clinical intervention and outcomes assessment should be recognized, managed and evaluated both from physiological, psychological, and spiritual status, and all the four dimensions: orthodox medicine (WM, Chinese medicine, etc.), individual inherent characteristics (emotion, attitude, psychology, etc.), cultural influences (doctors, caregivers, groups care, etc.), and natural environment and social systems (economic status, social security system, environmental pollution, etc). As for health outcomes assessment, a more comprehensive system including biological, doctors, patients, health intimate, social and environmental evaluations were required. The GIM model has individualized, dynamic, standardized, objective, systematic inherent characteristics, and opening and compatible external characteristics. It aims to provide the new theoretical guidance and strategic development direction for complex health interventions, and solve various medical related psychological and social problems.
Can we estimate total magnetization directions from aeromagnetic data using Helbig's integrals?
Phillips, J.D.
2005-01-01
An algorithm that implements Helbig's (1963) integrals for estimating the vector components (mx, my, mz) of tile magnetic dipole moment from the first order moments of the vector magnetic field components (??X, ??Y, ??Z) is tested on real and synthetic data. After a grid of total field aeromagnetic data is converted to vector component grids using Fourier filtering, Helbig's infinite integrals are evaluated as finite integrals in small moving windows using a quadrature algorithm based on the 2-D trapezoidal rule. Prior to integration, best-fit planar surfaces must be removed from the component data within the data windows in order to make the results independent of the coordinate system origin. Two different approaches are described for interpreting the results of the integration. In the "direct" method, results from pairs of different window sizes are compared to identify grid nodes where the angular difference between solutions is small. These solutions provide valid estimates of total magnetization directions for compact sources such as spheres or dipoles, but not for horizontally elongated or 2-D sources. In the "indirect" method, which is more forgiving of source geometry, results of the quadrature analysis are scanned for solutions that are parallel to a specified total magnetization direction.
Direct current power delivery system and method
Zhang, Di; Garces, Luis Jose; Dai, Jian; Lai, Rixin
2016-09-06
A power transmission system includes a first unit for carrying out the steps of receiving high voltage direct current (HVDC) power from an HVDC power line, generating an alternating current (AC) component indicative of a status of the first unit, and adding the AC component to the HVDC power line. Further, the power transmission system includes a second unit for carrying out the steps of generating a direct current (DC) voltage to transfer the HVDC power on the HVDC power line, wherein the HVDC power line is coupled between the first unit and the second unit, detecting a presence or an absence of the added AC component in the HVDC power line, and determining the status of the first unit based on the added AC component.
A direct method for photoacoustic tomography with inhomogeneous sound speed
NASA Astrophysics Data System (ADS)
Belhachmi, Zakaria; Glatz, Thomas; Scherzer, Otmar
2016-04-01
The standard approach for photoacoustic imaging with variable speed of sound is time reversal, which consists of solving a well-posed final-boundary value problem for the wave equation backwards in time. This paper investigates the iterative Landweber regularization algorithm, where convergence is guaranteed by standard regularization theory, notably also in cases of trapping sound speed or for short measurement times. We formulate and solve the direct and inverse problem on the whole Euclidean space, which is common in standard photoacoustic imaging, but not for time reversal algorithms, where the problems are considered on a domain enclosed by the measurement devices. We formulate both the direct and adjoint photoacoustic operator as the solution of an interior and an exterior differential equation which are coupled by transmission conditions. The former is solved numerically using a Galerkin scheme in space and finite difference discretization in time, while the latter consists of solving a boundary integral equation. We therefore use a boundary element method/finite element method approach for numerical solution of the forward operators. We analyze this method, prove convergence, and provide numerical tests. Moreover, we compare the approach to time reversal.
Methods of Genomic Competency Integration in Practice
Jenkins, Jean; Calzone, Kathleen A.; Caskey, Sarah; Culp, Stacey; Weiner, Marsha; Badzek, Laurie
2015-01-01
Purpose Genomics is increasingly relevant to health care, necessitating support for nurses to incorporate genomic competencies into practice. The primary aim of this project was to develop, implement, and evaluate a year-long genomic education intervention that trained, supported, and supervised institutional administrator and educator champion dyads to increase nursing capacity to integrate genomics through assessments of program satisfaction and institutional achieved outcomes. Design Longitudinal study of 23 Magnet Recognition Program® Hospitals (21 intervention, 2 controls) participating in a 1-year new competency integration effort aimed at increasing genomic nursing competency and overcoming barriers to genomics integration in practice. Methods Champion dyads underwent genomic training consisting of one in-person kick-off training meeting followed by monthly education webinars. Champion dyads designed institution-specific action plans detailing objectives, methods or strategies used to engage and educate nursing staff, timeline for implementation, and outcomes achieved. Action plans focused on a minimum of seven genomic priority areas: champion dyad personal development; practice assessment; policy content assessment; staff knowledge needs assessment; staff development; plans for integration; and anticipated obstacles and challenges. Action plans were updated quarterly, outlining progress made as well as inclusion of new methods or strategies. Progress was validated through virtual site visits with the champion dyads and chief nursing officers. Descriptive data were collected on all strategies or methods utilized, and timeline for achievement. Descriptive data were analyzed using content analysis. Findings The complexity of the competency content and the uniqueness of social systems and infrastructure resulted in a significant variation of champion dyad interventions. Conclusions Nursing champions can facilitate change in genomic nursing capacity through
77 FR 21158 - VA Directive 0005 on Scientific Integrity: Availability for Review and Comment
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-09
... AFFAIRS VA Directive 0005 on Scientific Integrity: Availability for Review and Comment AGENCY: Office of... (VA) Directive 0005 on Scientific Integrity. The Draft Directive incorporates the principles of scientific integrity contained in the Presidential Memorandum of March 9, 2009, and the Director, Office...
Solution methods for very highly integrated circuits.
Nong, Ryan; Thornquist, Heidi K.; Chen, Yao; Mei, Ting; Santarelli, Keith R.; Tuminaro, Raymond Stephen
2010-12-01
While advances in manufacturing enable the fabrication of integrated circuits containing tens-to-hundreds of millions of devices, the time-sensitive modeling and simulation necessary to design these circuits poses a significant computational challenge. This is especially true for mixed-signal integrated circuits where detailed performance analyses are necessary for the individual analog/digital circuit components as well as the full system. When the integrated circuit has millions of devices, performing a full system simulation is practically infeasible using currently available Electrical Design Automation (EDA) tools. The principal reason for this is the time required for the nonlinear solver to compute the solutions of large linearized systems during the simulation of these circuits. The research presented in this report aims to address the computational difficulties introduced by these large linearized systems by using Model Order Reduction (MOR) to (i) generate specialized preconditioners that accelerate the computation of the linear system solution and (ii) reduce the overall dynamical system size. MOR techniques attempt to produce macromodels that capture the desired input-output behavior of larger dynamical systems and enable substantial speedups in simulation time. Several MOR techniques that have been developed under the LDRD on 'Solution Methods for Very Highly Integrated Circuits' will be presented in this report. Among those presented are techniques for linear time-invariant dynamical systems that either extend current approaches or improve the time-domain performance of the reduced model using novel error bounds and a new approach for linear time-varying dynamical systems that guarantees dimension reduction, which has not been proven before. Progress on preconditioning power grid systems using multi-grid techniques will be presented as well as a framework for delivering MOR techniques to the user community using Trilinos and the Xyce circuit simulator
Fourier-sparsity integrated method for complex target ISAR imagery.
Gao, Xunzhang; Liu, Zhen; Chen, Haowen; Li, Xiang
2015-01-01
In existing sparsity-driven inverse synthetic aperture radar (ISAR) imaging framework a sparse recovery (SR) algorithm is usually applied to azimuth compression to achieve high resolution in the cross-range direction. For range compression, however, direct application of an SR algorithm is not very effective because the scattering centers resolved in the high resolution range profiles at different view angles always exhibit irregular range cell migration (RCM), especially for complex targets, which will blur the ISAR image. To alleviate the sparse recovery-induced RCM in range compression, a sparsity-driven framework for ISAR imaging named Fourier-sparsity integrated (FSI) method is proposed in this paper, which can simultaneously achieve better focusing performance in both the range and cross-range domains. Experiments using simulated data and real data demonstrate the superiority of our proposed framework over existing sparsity-driven methods and range-Doppler methods. PMID:25629707
Future Directions of Electromagnetic Methods for Hydrocarbon Applications
NASA Astrophysics Data System (ADS)
Strack, K. M.
2014-01-01
For hydrocarbon applications, seismic exploration is the workhorse of the industry. Only in the borehole, electromagnetic (EM) methods play a dominant role, as they are mostly used to determine oil reserves and to distinguish water from oil-bearing zones. Throughout the past 60 years, we had several periods with an increased interest in EM. This increased with the success of the marine EM industry and now electromagnetics in general is considered for many new applications. The classic electromagnetic methods are borehole, onshore and offshore, and airborne EM methods. Airborne is covered elsewhere (see Smith, this issue). Marine EM material is readily available from the service company Web sites, and here I will only mention some future technical directions that are visible. The marine EM success is being carried back to the onshore market, fueled by geothermal and unconventional hydrocarbon applications. Oil companies are listening to pro-EM arguments, but still are hesitant to go through the learning exercises as early adopters. In particular, the huge business drivers of shale hydrocarbons and reservoir monitoring will bring markets many times bigger than the entire marine EM market. Additional applications include support for seismic operations, sub-salt, and sub-basalt, all areas where seismic exploration is costly and inefficient. Integration with EM will allow novel seismic methods to be applied. In the borehole, anisotropy measurements, now possible, form the missing link between surface measurements and ground truth. Three-dimensional (3D) induction measurements are readily available from several logging contractors. The trend to logging-while-drilling measurements will continue with many more EM technologies, and the effort of controlling the drill bit while drilling including look-ahead-and-around the drill bit is going on. Overall, the market for electromagnetics is increasing, and a demand for EM capable professionals will continue. The emphasis will
Recent Advances in the Method of Forces: Integrated Force Method of Structural Analysis
NASA Technical Reports Server (NTRS)
Patnaik, Surya N.; Coroneos, Rula M.; Hopkins, Dale A.
1998-01-01
Stress that can be induced in an elastic continuum can be determined directly through the simultaneous application of the equilibrium equations and the compatibility conditions. In the literature, this direct stress formulation is referred to as the integrated force method. This method, which uses forces as the primary unknowns, complements the popular equilibrium-based stiffness method, which considers displacements as the unknowns. The integrated force method produces accurate stress, displacement, and frequency results even for modest finite element models. This version of the force method should be developed as an alternative to the stiffness method because the latter method, which has been researched for the past several decades, may have entered its developmental plateau. Stress plays a primary role in the development of aerospace and other products, and its analysis is difficult. Therefore, it is advisable to use both methods to calculate stress and eliminate errors through comparison. This paper examines the role of the integrated force method in analysis, animation and design.
CELSS system control: issues, methods, and directions.
Blackwell, C C; Blackwell, A L
1992-01-01
In the general control perspective, the CELSS concept implies a very complex system and presents challenges at every level. These challenges are generated by: (1) the prospect that the system will be inherently unstable, (2) the prospective difficulty of establishing an adequate mathematical model of the system for the purpose of control law synthesis (dimensionality is high, and the dynamics and interactive processes of some of the subsystems are not understood well), (3) assuring control law robustness (assuring that the resulting control law(s) will be effective over the domain of the specified uncertainties), (4) hardware realization of the control law, (5) hardware system robustness ("fault tolerance") and (6) achieving the logistics of the automation (or "management") aspects of the problem. A suggested organization of the problem, a sketch of the issues related to perceived difficulties, a commentary/evaluation of the issues, a review of methods available to address the issues, and a suggested strategy to address the broad CELSS systems control problem are presented.
CELSS system control: issues, methods, and directions
NASA Technical Reports Server (NTRS)
Blackwell, C. C.; Blackwell, A. L.
1992-01-01
In the general control perspective, the CELSS concept implies a very complex system and presents challenges at every level. These challenges are generated by: (1) the prospect that the system will be inherently unstable, (2) the prospective difficulty of establishing an adequate mathematical model of the system for the purpose of control law synthesis (dimensionality is high, and the dynamics and interactive processes of some of the subsystems are not understood well), (3) assuring control law robustness (assuring that the resulting control law(s) will be effective over the domain of the specified uncertainties), (4) hardware realization of the control law, (5) hardware system robustness ("fault tolerance") and (6) achieving the logistics of the automation (or "management") aspects of the problem. A suggested organization of the problem, a sketch of the issues related to perceived difficulties, a commentary/evaluation of the issues, a review of methods available to address the issues, and a suggested strategy to address the broad CELSS systems control problem are presented.
Path Integral Monte Carlo Methods for Fermions
NASA Astrophysics Data System (ADS)
Ethan, Ethan; Dubois, Jonathan; Ceperley, David
2014-03-01
In general, Quantum Monte Carlo methods suffer from a sign problem when simulating fermionic systems. This causes the efficiency of a simulation to decrease exponentially with the number of particles and inverse temperature. To circumvent this issue, a nodal constraint is often implemented, restricting the Monte Carlo procedure from sampling paths that cause the many-body density matrix to change sign. Unfortunately, this high-dimensional nodal surface is not a priori known unless the system is exactly solvable, resulting in uncontrolled errors. We will discuss two possible routes to extend the applicability of finite-temperatue path integral Monte Carlo. First we extend the regime where signful simulations are possible through a novel permutation sampling scheme. Afterwards, we discuss a method to variationally improve the nodal surface by minimizing a free energy during simulation. Applications of these methods will include both free and interacting electron gases, concluding with discussion concerning extension to inhomogeneous systems. Support from DOE DE-FG52-09NA29456, DE-AC52-07NA27344, LLNL LDRD 10- ERD-058, and the Lawrence Scholar program.
Integrability: mathematical methods for studying solitary waves theory
NASA Astrophysics Data System (ADS)
Wazwaz, Abdul-Majid
2014-03-01
real features in a variety of vital areas in science, technology and engineering. In recognition of the importance of solitary waves theory and the underlying concept of integrable equations, a variety of powerful methods have been developed to carry out the required analysis. Examples of such methods which have been advanced are the inverse scattering method, the Hirota bilinear method, the simplified Hirota method, the Bäcklund transformation method, the Darboux transformation, the Pfaffian technique, the Painlevé analysis, the generalized symmetry method, the subsidiary ordinary differential equation method, the coupled amplitude-phase formulation, the sine-cosine method, the sech-tanh method, the mapping and deformation approach and many new other methods. The inverse scattering method, viewed as a nonlinear analogue of the Fourier transform method, is a powerful approach that demonstrates the existence of soliton solutions through intensive computations. At the center of the theory of integrable equations lies the bilinear forms and Hirota's direct method, which can be used to obtain soliton solutions by using exponentials. The Bäcklund transformation method is a useful invariant transformation that transforms one solution into another of a differential equation. The Darboux transformation method is a well known tool in the theory of integrable systems. It is believed that there is a connection between the Bäcklund transformation and the Darboux transformation, but it is as yet not known. Archetypes of integrable equations are the Korteweg-de Vries (KdV) equation, the modified KdV equation, the sine-Gordon equation, the Schrödinger equation, the Vakhnenko equation, the KdV6 equation, the Burgers equation, the fifth-order Lax equation and many others. These equations yield soliton solutions, multiple soliton solutions, breather solutions, quasi-periodic solutions, kink solutions, homo-clinic solutions and other solutions as well. The couplings of linear and
The quantum bouncer by the path integral method
NASA Astrophysics Data System (ADS)
Goodings, D. A.; Szeredi, T.
1991-10-01
The path integral formulation of quantum mechanics in the semiclassical or WKB approximation provides a physically intuitive way of relating a classical system to its quantum analog. A fruitful way of studying quantum chaos is based upon applying the Gutzwiller periodic orbit sum rule, a result derived by the path integral method in the WKB approximation. This provides some motivation for learning about path integral techniques. In this paper a pedagogical example of the path integral formalism is presented in the hope of conveying the basic physical and mathematical concepts. The ``quantum bouncer'' is studied—the quantum version of a particle moving in one dimension above a perfectly reflecting surface while subject to a constant force directed toward the surface. The classical counterpart of this system is a ball bouncing on a floor in a constant gravitational field, collisions with the floor being assumed to be elastic. Path integration is used to derive the energy eigenvalues and eigenfunctions of the quantum bouncer in the WKB or semiclassical approximation. The results are shown to be the same as those obtained by solving the Schrödinger equation in the same approximation.
Fingerprint image enhancement method using directional median filter
NASA Astrophysics Data System (ADS)
Wu, Chaohong; Shi, Zhixin; Govindaraju, Venu
2004-08-01
The performance of any fingerprint recognizer highly depends on the fingerprint image quality. Different types of noises in the fingerprint images pose greater difficulty for recognizers. Most Automatic Fingerprint Identification Systems (AFIS) use some form of image enhancement. Although several methods have been described in the literature, there is still scope for improvement. In particular, effective methodology of cleaning the valleys between the ridge contours are lacking. We observe that noisy valley pixels and the pixels in the interrupted ridge flow gap are "impulse noises". Therefore, this paper describes a new approach to fingerprint image enhancement, which is based on integration of Anisotropic Filter and directional median filter(DMF). Gaussian-distributed noises are reduced effectively by Anisotropic Filter, "impulse noises" are reduced efficiently by DMF. Usually, traditional median filter is the most effective method to remove pepper-and-salt noise and other small artifacts, the proposed DMF can not only finish its original tasks, it can also join broken fingerprint ridges, fill out the holes of fingerprint images, smooth irregular ridges as well as remove some annoying small artifacts between ridges. The enhancement algorithm has been implemented and tested on fingerprint images from FVC2002. Images of varying quality have been used to evaluate the performance of our approach. We have compared our method with other methods described in the literature in terms of matched minutiae, missed minutiae, spurious minutiae, and flipped minutiae(between end points and bifurcation points). Experimental results show our method to be superior to those described in the literature.
Borja, Angel; Bricker, Suzanne B; Dauer, Daniel M; Demetriades, Nicolette T; Ferreira, João G; Forbes, Anthony T; Hutchings, Pat; Jia, Xiaoping; Kenchington, Richard; Carlos Marques, João; Zhu, Changbo
2008-09-01
In recent years, several sets of legislation worldwide (Oceans Act in USA, Australia or Canada; Water Framework Directive or Marine Strategy in Europe, National Water Act in South Africa, etc.) have been developed in order to address ecological quality or integrity, within estuarine and coastal systems. Most such legislation seeks to define quality in an integrative way, by using several biological elements, together with physico-chemical and pollution elements. Such an approach allows assessment of ecological status at the ecosystem level ('ecosystem approach' or 'holistic approach' methodologies), rather than at species level (e.g. mussel biomonitoring or Mussel Watch) or just at chemical level (i.e. quality objectives) alone. Increasing attention has been paid to the development of tools for different physico-chemical or biological (phytoplankton, zooplankton, benthos, algae, phanerogams, fishes) elements of the ecosystems. However, few methodologies integrate all the elements into a single evaluation of a water body. The need for such integrative tools to assess ecosystem quality is very important, both from a scientific and stakeholder point of view. Politicians and managers need information from simple and pragmatic, but scientifically sound methodologies, in order to show to society the evolution of a zone (estuary, coastal area, etc.), taking into account human pressures or recovery processes. These approaches include: (i) multidisciplinarity, inherent in the teams involved in their implementation; (ii) integration of biotic and abiotic factors; (iii) accurate and validated methods in determining ecological integrity; and (iv) adequate indicators to follow the evolution of the monitored ecosystems. While some countries increasingly use the establishment of marine parks to conserve marine biodiversity and ecological integrity, there is awareness (e.g. in Australia) that conservation and management of marine ecosystems cannot be restricted to Marine Protected
Borja, Angel; Bricker, Suzanne B; Dauer, Daniel M; Demetriades, Nicolette T; Ferreira, João G; Forbes, Anthony T; Hutchings, Pat; Jia, Xiaoping; Kenchington, Richard; Carlos Marques, João; Zhu, Changbo
2008-09-01
In recent years, several sets of legislation worldwide (Oceans Act in USA, Australia or Canada; Water Framework Directive or Marine Strategy in Europe, National Water Act in South Africa, etc.) have been developed in order to address ecological quality or integrity, within estuarine and coastal systems. Most such legislation seeks to define quality in an integrative way, by using several biological elements, together with physico-chemical and pollution elements. Such an approach allows assessment of ecological status at the ecosystem level ('ecosystem approach' or 'holistic approach' methodologies), rather than at species level (e.g. mussel biomonitoring or Mussel Watch) or just at chemical level (i.e. quality objectives) alone. Increasing attention has been paid to the development of tools for different physico-chemical or biological (phytoplankton, zooplankton, benthos, algae, phanerogams, fishes) elements of the ecosystems. However, few methodologies integrate all the elements into a single evaluation of a water body. The need for such integrative tools to assess ecosystem quality is very important, both from a scientific and stakeholder point of view. Politicians and managers need information from simple and pragmatic, but scientifically sound methodologies, in order to show to society the evolution of a zone (estuary, coastal area, etc.), taking into account human pressures or recovery processes. These approaches include: (i) multidisciplinarity, inherent in the teams involved in their implementation; (ii) integration of biotic and abiotic factors; (iii) accurate and validated methods in determining ecological integrity; and (iv) adequate indicators to follow the evolution of the monitored ecosystems. While some countries increasingly use the establishment of marine parks to conserve marine biodiversity and ecological integrity, there is awareness (e.g. in Australia) that conservation and management of marine ecosystems cannot be restricted to Marine Protected
Maintaining Institutional Integrity. New Directions for Community Colleges, Number 52.
ERIC Educational Resources Information Center
Puyear, Donald E., Ed.; Vaughan, George B., Ed.
1985-01-01
This collection of articles addresses ways in which community colleges can maintain institutional integrity while at the same time adapting the colleges' mission to a changing environment. The following articles are included: (1) "The Search for Mission and Integrity: A Retrospective View," by Jennings L. Wagoner, Jr.; (2) "Maintaining Open Access…
An integrated curriculum: evolution, evaluation, and future direction.
Howard, Katherine M; Stewart, Tanis; Woodall, Wendy; Kingsley, Karl; Ditmyer, Marcia
2009-08-01
The topic of curriculum reform has received an enormous amount of attention in the field of dental education. While recently established dental schools benefit from the evolution of curriculum change and innovation in constructing their new curricula, these advantages can become lost if the curriculum is not assessed to ascertain the degree to which the curriculum accurately reflects the initial intended goals. The purpose of this educational research project was to evaluate a dental school curriculum to determine the extent of vertical and horizontal integration originally intended. After a faculty retreat that presented a historical perspective and prevalent concepts of the definitions of an integrated curriculum, a survey instrument was distributed to all course directors asking them to assign each of their courses to one of ten established models of integration. Analysis of the survey results allowed the mapping of each of the eighty-four courses to four themes of integration. Chi-square analysis demonstrated courses were distributed in a classic bell-shaped curve along the integration continuum. Dental school year 4 courses mapped to the highest levels of integration, while no courses were assigned to the lowest level (fragment or silo model). All courses were found to have at least some level of integration. More than half (n=43) were found to be both horizontally and vertically integrated.
Boundary integral methods for microfluidic problems
NASA Astrophysics Data System (ADS)
Burbidge, Adam
2015-01-01
Microscale experiments of reduced complexity allow one to tease out and examine some of the interesting phenomena that manifest in large hierarchically structured materials which are of general interest across many industries. Recent advances in high speed imaging techniques and post-processing allow experiments to yield small scale information which was previously unavailable, or extremely difficult to obtain. This additional information provides new challenges in terms of theoretical understanding and prediction that requires new tools. We discuss generalised weighted residual numerical methods as a means of solving physically derived systems of PDEs, using the steady Stokes equation as an example. These formulations require integration of arbitrary functions of submanifolds which often will have a lower dimensionality than the parent manifold, leading to cumbersome calculations of the Jacobian determinant. We provide a tensorial view of the transformation, in which the natural element coordinate system is a non-orthogonal frame, and derive an expression for the Jacobian factor in terms of the contravariant metric tensor gij. This approach has the additional advantage that it can be extended to yield the local surface curvature, which will be essential for correct implementation of free surface boundaries.
Boundary integral methods for unsaturated flow
Martinez, M.J.; McTigue, D.F.
1990-12-31
Many large simulations may be required to assess the performance of Yucca Mountain as a possible site for the nations first high level nuclear waste repository. A boundary integral equation method (BIEM) is described for numerical analysis of quasilinear steady unsaturated flow in homogeneous material. The applicability of the exponential model for the dependence of hydraulic conductivity on pressure head is discussed briefly. This constitutive assumption is at the heart of the quasilinear transformation. Materials which display a wide distribution in pore-size are described reasonably well by the exponential. For materials with a narrow range in pore-size, the exponential is suitable over more limited ranges in pressure head. The numerical implementation of the BIEM is used to investigate the infiltration from a strip source to a water table. The net infiltration of moisture into a finite-depth layer is well-described by results for a semi-infinite layer if {alpha}D > 4, where {alpha} is the sorptive number and D is the depth to the water table. the distribution of moisture exhibits a similar dependence on {alpha}D. 11 refs., 4 figs.,
Boundary-integral methods in elasticity and plasticity. [solutions of boundary value problems
NASA Technical Reports Server (NTRS)
Mendelson, A.
1973-01-01
Recently developed methods that use boundary-integral equations applied to elastic and elastoplastic boundary value problems are reviewed. Direct, indirect, and semidirect methods using potential functions, stress functions, and displacement functions are described. Examples of the use of these methods for torsion problems, plane problems, and three-dimensional problems are given. It is concluded that the boundary-integral methods represent a powerful tool for the solution of elastic and elastoplastic problems.
Charting the information technology direction for an integrated delivery system.
Scott, H H
1998-01-01
Automating the healthcare integrated delivery system requires a special set of skills, talent, and communication that goes beyond the capability of the i.t. manager alone. Bringing together all elements of the integrated delivery system and forming a well-integrated information environment will require a level of teamwork rarely seen in any industry. Today's IT manager is like an orchestra conductor. He or she should look ahead in the musical composition, manage the tempo, and bring all the sounds of the eclectic set of instruments together in harmony and achievement of the melody. Following the key success factor outlined here may not guarantee success in automating the integrated delivery system, but following them should keep the process harmonious.
Methods and systems for integrating fluid dispensing technology with stereolithography
Medina, Francisco; Wicker, Ryan; Palmer, Jeremy A.; Davis, Don W.; Chavez, Bart D.; Gallegos, Phillip L.
2010-02-09
An integrated system and method of integrating fluid dispensing technologies (e.g., direct-write (DW)) with rapid prototyping (RP) technologies (e.g., stereolithography (SL)) without part registration comprising: an SL apparatus and a fluid dispensing apparatus further comprising a translation mechanism adapted to translate the fluid dispensing apparatus along the Z-, Y- and Z-axes. The fluid dispensing apparatus comprises: a pressurized fluid container; a valve mechanism adapted to control the flow of fluid from the pressurized fluid container; and a dispensing nozzle adapted to deposit the fluid in a desired location. To aid in calibration, the integrated system includes a laser sensor and a mechanical switch. The method further comprises building a second part layer on top of the fluid deposits and optionally accommodating multi-layered circuitry by incorporating a connector trace. Thus, the present invention is capable of efficiently building single and multi-material SL fabricated parts embedded with complex three-dimensional circuitry using DW.
Numerical solution of integral-algebraic equations for multistep methods
NASA Astrophysics Data System (ADS)
Budnikova, O. S.; Bulatov, M. V.
2012-05-01
Systems of Volterra linear integral equations with identically singular matrices in the principal part (called integral-algebraic equations) are examined. Multistep methods for the numerical solution of a selected class of such systems are proposed and justified.
A Modified Alternating Direction Method for Variational Inequality Problems
Han, D.
2002-07-01
The alternating direction method is an attractive method for solving large-scale variational inequality problems whenever the subproblems can be solved efficiently. However, the subproblems are still variational inequality problems, which are as structurally difficult to solve as the original one. To overcome this disadvantage, in this paper we propose a new alternating direction method for solving a class of nonlinear monotone variational inequality problems. In each iteration the method just makes an orthogonal projection to a simple set and some function evaluations. We report some preliminary computational results to illustrate the efficiency of the method.
Calculation of transonic flows using an extended integral equation method
NASA Technical Reports Server (NTRS)
Nixon, D.
1976-01-01
An extended integral equation method for transonic flows is developed. In the extended integral equation method velocities in the flow field are calculated in addition to values on the aerofoil surface, in contrast with the less accurate 'standard' integral equation method in which only surface velocities are calculated. The results obtained for aerofoils in subcritical flow and in supercritical flow when shock waves are present compare satisfactorily with the results of recent finite difference methods.
Direct Linear Transformation Method for Three-Dimensional Cinematography
ERIC Educational Resources Information Center
Shapiro, Robert
1978-01-01
The ability of Direct Linear Transformation Method for three-dimensional cinematography to locate points in space was shown to meet the accuracy requirements associated with research on human movement. (JD)
Pervasive genetic integration directs the evolution of human skull shape.
Martínez-Abadías, Neus; Esparza, Mireia; Sjøvold, Torstein; González-José, Rolando; Santos, Mauro; Hernández, Miquel; Klingenberg, Christian Peter
2012-04-01
It has long been unclear whether the different derived cranial traits of modern humans evolved independently in response to separate selection pressures or whether they resulted from the inherent morphological integration throughout the skull. In a novel approach to this issue, we combine evolutionary quantitative genetics and geometric morphometrics to analyze genetic and phenotypic integration in human skull shape. We measured human skulls in the ossuary of Hallstatt (Austria), which offer a unique opportunity because they are associated with genealogical data. Our results indicate pronounced covariation of traits throughout the skull. Separate simulations of selection for localized shape changes corresponding to some of the principal derived characters of modern human skulls produced outcomes that were similar to each other and involved a joint response in all of these traits. The data for both genetic and phenotypic shape variation were not consistent with the hypothesis that the face, cranial base, and cranial vault are completely independent modules but relatively strongly integrated structures. These results indicate pervasive integration in the human skull and suggest a reinterpretation of the selective scenario for human evolution where the origin of any one of the derived characters may have facilitated the evolution of the others.
A study of direct moxibustion using mathematical methods.
Liu, Miao; Kauh, Sang Ken; Lim, Sabina
2012-01-01
Direct moxibustion is an important and widely used treatment method in traditional medical science. The use of a mathematical method to analyse direct moxibustion treatment is necessary and helpful in exploring the new direct moxibustion instruments and their standardisation. Thus, this paper aims to use a mathematical method to study direct moxibustion in skin to demonstrate a direct relationship between direct moxibustion and skin stimuli. In this paper, the transient thermal response of skin layers is analysed to study direct moxibustion using the data got from standardised method to measure the temperature of a burning moxa cone. Numerical simulations based on an appropriate finite element model are developed to predict the heat transfer, thermal damage and thermal stress distribution of barley moxa cones and jujube moxa cones in the skin tissue. The results are verified by the ancient literatures of traditional Chinese medicine and clinical application, and showed that mathematical method can be a good interface between moxa cone and skin tissue providing the numerical value basis for moxibustion.
NASA Technical Reports Server (NTRS)
Nixon, D.
1978-01-01
The linear transonic perturbation integral equation previously derived for nonlifting airfoils is formulated for lifting cases. In order to treat shock wave motions, a strained coordinate system is used in which the shock location is invariant. The tangency boundary conditions are either formulated using the thin airfoil approximation or by using the analytic continuation concept. A direct numerical solution to this equation is derived in contrast to the iterative scheme initially used, and results of both lifting and nonlifting examples indicate that the method is satisfactory.
Bridging the gap: using direct payments to purchase integrated care.
Glendinning, Caroline; Halliwell, Shirley; Jacobs, Sally; Rummery, Kerstein; Tyrer, Jane
2000-05-01
This paper reports on a study of disabled people with receiving Direct Payments who were able to purchase assistance in ways that cross conventional boundaries between 'health' and 'social' services. Indeed, most of the Direct Payment recipients used the term 'personal care' to describe a range of help that extended right across this conventional divide. Nevertheless, most of the users reported purchasing help with aspects of health care through their Direct Payments, including physiotherapy, management of incontinence, chiropody, changing dressings and sustaining tissue viability. They chose to purchase this help from their personal assistants (PAs) because statutory services were not available, had been withdrawn, or because they were able to retain greater independence and control over their lives compared with receiving conventional services. Many Direct Payment users wanted more opportunities to purchase a range of health-related services, although this also raised questions about training, supervision and the professionalisation of flexible personal assistance. The paper concludes that health purchasers may need to consider contributing to Direct Payments in acknowledgement of the health care which such schemes are currently providing.
Method speeds tapered rod design for directional well
Hu Yongquan; Yuan Xiangzhong
1995-10-16
Determination of the minimum rod diameter, from statistical relationships, can decrease the time needed for designing a sucker-rod string for a directional well. A tapered rod string design for a directional well is more complex than for a vertical well. Based on the theory of a continuous beam column, the rod string design in a directional well is a trial and error method. The key to reduce the time to obtain a solution is to rapidly determine the minimum rod diameter. This can be done with a statistical relationship. The paper describes sucker rods, design method, basic analysis rod design, and minimum rod diameter.
Electron beam directed energy device and methods of using same
Retsky, Michael W.
2007-10-16
A method and apparatus is disclosed for an electron beam directed energy device. The device consists of an electron gun with one or more electron beams. The device includes one or more accelerating plates with holes aligned for beam passage. The plates may be flat or preferably shaped to direct each electron beam to exit the electron gun at a predetermined orientation. In one preferred application, the device is located in outer space with individual beams that are directed to focus at a distant target to be used to impact and destroy missiles. The aimings of the separate beams are designed to overcome Coulomb repulsion. A method is also presented for directing the beams to a target considering the variable terrestrial magnetic field. In another preferred application, the electron beam is directed into the ground to produce a subsurface x-ray source to locate and/or destroy buried or otherwise hidden objects including explosive devices.
An Integrative Conceptual Framework of Disability: New Directions for Research.
ERIC Educational Resources Information Center
Tate, Denise G.; Pledger, Constance
2003-01-01
Examines various disability paradigms across time, assessing the relative contribution of the socioecological perspective in guiding research designed to improve the lives of people with disabilities. Recommends new research directions that include a focus on life span issues, biomedicine, biotechnology, the efficacy and effectiveness of current…
Psychiatric Advance Directives and Social Workers: An Integrative Review
ERIC Educational Resources Information Center
Van Dorn, Richard A.; Scheyett, Anna; Swanson, Jeffrey W.; Swartz, Marvin S.
2010-01-01
Psychiatric advance directives (PADs) are legal documents that allow individuals to express their wishes for future psychiatric care and to authorize a legally appointed proxy to make decisions on their behalf during incapacitating crises. PADs are viewed as an alternative to the coercive interventions that sometimes accompany mental health crises…
77 FR 67063 - VA Directive 0005 on Scientific Integrity
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-08
... April 9, 2012 (77 FR 21158). FOR FURTHER INFORMATION CONTACT: Billy E. Jones, M.D., Senior Advisor to... http://www1.va.gov/vapubs/ . Directive 0005 establishes VA policies that: Foster a culture of... technological information from political or commercial influence; Prohibit suppression or alteration...
Small earth station antenna synthesized by a direct PO method
NASA Astrophysics Data System (ADS)
Schlobohm, Bernd; Arndt, Fritz
1990-11-01
An efficient direct numerical synthesis method for dual offset reflector antennas is described which is based on the physical optics (PO) procedure. The method involves an evolution-strategy optimization algorithm in order to shape both reflectors directly, so as to generate the desired far field with prescribed criteria. The efficiency of the design method is demonstrated by the example of a compact Gregorian dual-offset earth-station antenna with high offset angle (70 deg) and small subreflector size (13 lambda); 75 percent antenna efficiency, 38 dB cross-polarization attenuation, and a very low sidelobe behavior of about 23-25 log theta dBi are achieved.
Integrated navigation method based on inertial navigation system and Lidar
NASA Astrophysics Data System (ADS)
Zhang, Xiaoyue; Shi, Haitao; Pan, Jianye; Zhang, Chunxi
2016-04-01
An integrated navigation method based on the inertial navigational system (INS) and Lidar was proposed for land navigation. Compared with the traditional integrated navigational method and dead reckoning (DR) method, the influence of the inertial measurement unit (IMU) scale factor and misalignment was considered in the new method. First, the influence of the IMU scale factor and misalignment on navigation accuracy was analyzed. Based on the analysis, the integrated system error model of INS and Lidar was established, in which the IMU scale factor and misalignment error states were included. Then the observability of IMU error states was analyzed. According to the results of the observability analysis, the integrated system was optimized. Finally, numerical simulation and a vehicle test were carried out to validate the availability and utility of the proposed INS/Lidar integrated navigational method. Compared with the test result of a traditional integrated navigation method and DR method, the proposed integrated navigational method could result in a higher navigation precision. Consequently, the IMU scale factor and misalignment error were effectively compensated by the proposed method and the new integrated navigational method is valid.
New directions for Artificial Intelligence (AI) methods in optimum design
NASA Technical Reports Server (NTRS)
Hajela, Prabhat
1989-01-01
Developments and applications of artificial intelligence (AI) methods in the design of structural systems is reviewed. Principal shortcomings in the current approach are emphasized, and the need for some degree of formalism in the development environment for such design tools is underscored. Emphasis is placed on efforts to integrate algorithmic computations in expert systems.
Wang, Pengfei; Hatta, Agus Muhamad; Zhao, Haoyu; Zheng, Jie; Farrell, Gerald; Brambilla, Gilberto
2015-01-01
A ratiometric wavelength measurement based on a Silicon-on-Insulator (SOI) integrated device is proposed and designed, which consists of directional couplers acting as two edge filters with opposite spectral responses. The optimal separation distance between two parallel silicon waveguides and the interaction length of the directional coupler are designed to meet the desired spectral response by using local supermodes. The wavelength discrimination ability of the designed ratiometric structure is demonstrated by a beam propagation method numerically and then is verified experimentally. The experimental results have shown a general agreement with the theoretical models. The ratiometric wavelength system demonstrates a resolution of better than 50 pm at a wavelength around 1550 nm with ease of assembly and calibration. PMID:26343668
Integrated GNSS Attitude Determination and Positioning for Direct Geo-Referencing
Nadarajah, Nandakumaran; Paffenholz, Jens-André; Teunissen, Peter J. G.
2014-01-01
Direct geo-referencing is an efficient methodology for the fast acquisition of 3D spatial data. It requires the fusion of spatial data acquisition sensors with navigation sensors, such as Global Navigation Satellite System (GNSS) receivers. In this contribution, we consider an integrated GNSS navigation system to provide estimates of the position and attitude (orientation) of a 3D laser scanner. The proposed multi-sensor system (MSS) consists of multiple GNSS antennas rigidly mounted on the frame of a rotating laser scanner and a reference GNSS station with known coordinates. Precise GNSS navigation requires the resolution of the carrier phase ambiguities. The proposed method uses the multivariate constrained integer least-squares (MC-LAMBDA) method for the estimation of rotating frame ambiguities and attitude angles. MC-LAMBDA makes use of the known antenna geometry to strengthen the underlying attitude model and, hence, to enhance the reliability of rotating frame ambiguity resolution and attitude determination. The reliable estimation of rotating frame ambiguities is consequently utilized to enhance the relative positioning of the rotating frame with respect to the reference station. This integrated (array-aided) method improves ambiguity resolution, as well as positioning accuracy between the rotating frame and the reference station. Numerical analyses of GNSS data from a real-data campaign confirm the improved performance of the proposed method over the existing method. In particular, the integrated method yields reliable ambiguity resolution and reduces position standard deviation by a factor of about 0.8, matching the theoretical gain of 3/4 for two antennas on the rotating frame and a single antenna at the reference station. PMID:25036330
Integrated GNSS attitude determination and positioning for direct geo-referencing.
Nadarajah, Nandakumaran; Paffenholz, Jens-André; Teunissen, Peter J G
2014-07-17
Direct geo-referencing is an efficient methodology for the fast acquisition of 3D spatial data. It requires the fusion of spatial data acquisition sensors with navigation sensors, such as Global Navigation Satellite System (GNSS) receivers. In this contribution, we consider an integrated GNSS navigation system to provide estimates of the position and attitude (orientation) of a 3D laser scanner. The proposed multi-sensor system (MSS) consists of multiple GNSS antennas rigidly mounted on the frame of a rotating laser scanner and a reference GNSS station with known coordinates. Precise GNSS navigation requires the resolution of the carrier phase ambiguities. The proposed method uses the multivariate constrained integer least-squares (MC-LAMBDA) method for the estimation of rotating frame ambiguities and attitude angles. MC-LAMBDA makes use of the known antenna geometry to strengthen the underlying attitude model and, hence, to enhance the reliability of rotating frame ambiguity resolution and attitude determination. The reliable estimation of rotating frame ambiguities is consequently utilized to enhance the relative positioning of the rotating frame with respect to the reference station. This integrated (array-aided) method improves ambiguity resolution, as well as positioning accuracy between the rotating frame and the reference station. Numerical analyses of GNSS data from a real-data campaign confirm the improved performance of the proposed method over the existing method. In particular, the integrated method yields reliable ambiguity resolution and reduces position standard deviation by a factor of about 0:8, matching the theoretical gain of √ 3/4 for two antennas on the rotating frame and a single antenna at the reference station.
Integrated GNSS attitude determination and positioning for direct geo-referencing.
Nadarajah, Nandakumaran; Paffenholz, Jens-André; Teunissen, Peter J G
2014-01-01
Direct geo-referencing is an efficient methodology for the fast acquisition of 3D spatial data. It requires the fusion of spatial data acquisition sensors with navigation sensors, such as Global Navigation Satellite System (GNSS) receivers. In this contribution, we consider an integrated GNSS navigation system to provide estimates of the position and attitude (orientation) of a 3D laser scanner. The proposed multi-sensor system (MSS) consists of multiple GNSS antennas rigidly mounted on the frame of a rotating laser scanner and a reference GNSS station with known coordinates. Precise GNSS navigation requires the resolution of the carrier phase ambiguities. The proposed method uses the multivariate constrained integer least-squares (MC-LAMBDA) method for the estimation of rotating frame ambiguities and attitude angles. MC-LAMBDA makes use of the known antenna geometry to strengthen the underlying attitude model and, hence, to enhance the reliability of rotating frame ambiguity resolution and attitude determination. The reliable estimation of rotating frame ambiguities is consequently utilized to enhance the relative positioning of the rotating frame with respect to the reference station. This integrated (array-aided) method improves ambiguity resolution, as well as positioning accuracy between the rotating frame and the reference station. Numerical analyses of GNSS data from a real-data campaign confirm the improved performance of the proposed method over the existing method. In particular, the integrated method yields reliable ambiguity resolution and reduces position standard deviation by a factor of about 0:8, matching the theoretical gain of √ 3/4 for two antennas on the rotating frame and a single antenna at the reference station. PMID:25036330
High Throughput Screening and Selection Methods for Directed Enzyme Evolution
2015-01-01
Successful evolutionary enzyme engineering requires a high throughput screening or selection method, which considerably increases the chance of obtaining desired properties and reduces the time and cost. In this review, a series of high throughput screening and selection methods are illustrated with significant and recent examples. These high throughput strategies are also discussed with an emphasis on compatibility with phenotypic analysis during directed enzyme evolution. Lastly, certain limitations of current methods, as well as future developments, are briefly summarized. PMID:26074668
Unmanned aerial vehicle trajectory planning with direct methods
NASA Astrophysics Data System (ADS)
Geiger, Brian
A real-time method for trajectory optimization to maximize surveillance time of a fixed or moving ground target by one or more unmanned aerial vehicles (UAVs) is presented. The method accounts for performance limits of the aircraft, intrinsic properties of the camera, and external disturbances such as wind. Direct collocation with nonlinear programming is used to implement the method in simulation and onboard the Penn State/Applied Research Lab's testbed UAV. Flight test results compare well with simulation. Both stationary targets and moving targets, such as a low flying UAV, were successfully tracked in flight test. In addition, a new method using a neural network approximation is presented that removes the need for collocation and numerical derivative calculation. Neural networks are used to approximate the objective and dynamics functions in the optimization problem which allows for reduced computation requirements. The approximation reduces the size of the resulting nonlinear programming problem compared to direct collocation or pseudospectral methods. This method is shown to be faster than direct collocation and psuedospectral methods using numerical or automatic derivative techniques. The neural network approximation is also shown to be faster than analytical derivatives but by a lesser factor. Comparative results are presented showing similar accuracy for all methods. The method is modular and enables application to problems of the same class without network retraining.
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.
NASA Astrophysics Data System (ADS)
Hesch, Christian; Betsch, Peter
2011-10-01
The present work deals with the development of an energy-momentum conserving method to unilateral contact constraints and is a direct continuation of a previous work (Hesch and Betsch in Comput Mech 2011, doi: 10.1007/s00466-011-0597-2) dealing with the NTS method. In this work, we introduce the mortar method and a newly developed segmentation process for the consistent integration of the contact interface. For the application of the energy-momentum approach to mortar constraints, we extend an approach based on a mixed formulation to the segment definition of the mortar constraints. The enhanced numerical stability of the newly proposed discretization method will be shown in several examples.
Accelerometer method and apparatus for integral display and control functions
NASA Technical Reports Server (NTRS)
Bozeman, Richard J., Jr. (Inventor)
1992-01-01
Vibration analysis has been used for years to provide a determination of the proper functioning of different types of machinery, including rotating machinery and rocket engines. A determination of a malfunction, if detected at a relatively early stage in its development, will allow changes in operating mode or a sequenced shutdown of the machinery prior to a total failure. Such preventative measures result in less extensive and/or less expensive repairs, and can also prevent a sometimes catastrophic failure of equipment. Standard vibration analyzers are generally rather complex, expensive, and of limited portability. They also usually result in displays and controls being located remotely from the machinery being monitored. Consequently, a need exists for improvements in accelerometer electronic display and control functions which are more suitable for operation directly on machines and which are not so expensive and complex. The invention includes methods and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. The apparatus includes an accelerometer package having integral display and control functions. The accelerometer package is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine condition over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase over the selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated. The benefits of a vibration recording and monitoring system with controls and displays readily
Apparatus and method for a light direction sensor
NASA Technical Reports Server (NTRS)
Leviton, Douglas B. (Inventor)
2011-01-01
The present invention provides a light direction sensor for determining the direction of a light source. The system includes an image sensor; a spacer attached to the image sensor, and a pattern mask attached to said spacer. The pattern mask has a slit pattern that as light passes through the slit pattern it casts a diffraction pattern onto the image sensor. The method operates by receiving a beam of light onto a patterned mask, wherein the patterned mask as a plurality of a slit segments. Then, diffusing the beam of light onto an image sensor and determining the direction of the light source.
Calculation of unsteady transonic flows using the integral equation method
NASA Technical Reports Server (NTRS)
Nixon, D.
1978-01-01
The basic integral equations for a harmonically oscillating airfoil in a transonic flow with shock waves are derived; the reduced frequency is assumed to be small. The problems associated with shock wave motion are treated using a strained coordinate system. The integral equation is linear and consists of both line integrals and surface integrals over the flow field which are evaluated by quadrature. This leads to a set of linear algebraic equations that can be solved directly. The shock motion is obtained explicitly by enforcing the condition that the flow is continuous except at a shock wave. Results obtained for both lifting and nonlifting oscillatory flows agree satisfactorily with other accurate results.
Some aspects of integral transport method for deep penetration problem
Takahashi, H.
1982-01-01
An analytical expression of the integral transport method for an experimental hole in fission reactors has been developed. This analytical method might still be useful for designing a fusion reactor without using large computer machine time.
NASA Astrophysics Data System (ADS)
Choudhury, A. Ghose; Guha, Partha; Khanra, Barun
2009-10-01
The Darboux integrability method is particularly useful to determine first integrals of nonplanar autonomous systems of ordinary differential equations, whose associated vector fields are polynomials. In particular, we obtain first integrals for a variant of the generalized Raychaudhuri equation, which has appeared in string inspired modern cosmology.
Integration design of endoscopes with different viewing directions
NASA Astrophysics Data System (ADS)
Zhang, Lingyun; Cheng, Dewen; Wang, Yongtian
2015-09-01
High definition and magnification rigid endoscope is a significant equipment in the examination and surgery. In this paper, the design of a high definition (HD) rigid endoscope is presented with a FOV of 70°. The entrance pupil is 0.3 mm, achieved for the first time to our best knowledge. For the fabricated prototype, the theoretical resolution is 22.3 lp/mm at an object distance of 20 mm, the depth of field (DOF) is 115 mm and the stray light is eliminated effectively. The viewing angle of the developed endoscope is zero. However, the endoscope with non-zero viewing angle is more popular in some conditions, we present two designs with non-zero viewing direction for better observation and diagnosis of lesions on inner walls of organs and tissues.
Integrated molecular mechanism directing nucleosome reorganization by human FACT
Tsunaka, Yasuo; Fujiwara, Yoshie; Oyama, Takuji; Hirose, Susumu; Morikawa, Kosuke
2016-01-01
Facilitates chromatin transcription (FACT) plays essential roles in chromatin remodeling during DNA transcription, replication, and repair. Our structural and biochemical studies of human FACT–histone interactions present precise views of nucleosome reorganization, conducted by the FACT-SPT16 (suppressor of Ty 16) Mid domain and its adjacent acidic AID segment. AID accesses the H2B N-terminal basic region exposed by partial unwrapping of the nucleosomal DNA, thereby triggering the invasion of FACT into the nucleosome. The crystal structure of the Mid domain complexed with an H3–H4 tetramer exhibits two separate contact sites; the Mid domain forms a novel intermolecular β structure with H4. At the other site, the Mid–H2A steric collision on the H2A-docking surface of the H3–H4 tetramer within the nucleosome induces H2A–H2B displacement. This integrated mechanism results in disrupting the H3 αN helix, which is essential for retaining the nucleosomal DNA ends, and hence facilitates DNA stripping from histone. PMID:26966247
Thermally integrated staged methanol reformer and method
Skala, Glenn William; Hart-Predmore, David James; Pettit, William Henry; Borup, Rodney Lynn
2001-01-01
A thermally integrated two-stage methanol reformer including a heat exchanger and first and second reactors colocated in a common housing in which a gaseous heat transfer medium circulates to carry heat from the heat exchanger into the reactors. The heat transfer medium comprises principally hydrogen, carbon dioxide, methanol vapor and water vapor formed in a first stage reforming reaction. A small portion of the circulating heat transfer medium is drawn off and reacted in a second stage reforming reaction which substantially completes the reaction of the methanol and water remaining in the drawn-off portion. Preferably, a PrOx reactor will be included in the housing upstream of the heat exchanger to supplement the heat provided by the heat exchanger.
Radiation direction control by optical slot antenna integrated with plasmonic waveguide
NASA Astrophysics Data System (ADS)
Park, Yeonsang; Kim, Jineun; Roh, Young-Geun; Lee, Chang-Won
2016-04-01
We present an optical slot antenna integrated with a metal-dielectric-metal (MIM) plasmonic waveguide. By integrating optical slot antenna on top metal layer of MIM waveguide, we can couple the plasmon guide mode into the feed antenna directly. The resonantly excited slot antenna works as a magnetic dipole and then radiates in dipole-like far-field pattern. By adding an auxiliary groove structure along with the slot antenna, the radiation can be directed into the direction where the structure determined. The demonstrated optical slot antenna integrated with a plasmonic waveguide can be used as a "plasmonic via" in plasmonic nanocircuits.
Direct Solve of Electrically Large Integral Equations for Problem Sizes to 1M Unknowns
NASA Technical Reports Server (NTRS)
Shaeffer, John
2008-01-01
Matrix methods for solving integral equations via direct solve LU factorization are presently limited to weeks to months of very expensive supercomputer time for problems sizes of several hundred thousand unknowns. This report presents matrix LU factor solutions for electromagnetic scattering problems for problem sizes to one million unknowns with thousands of right hand sides that run in mere days on PC level hardware. This EM solution is accomplished by utilizing the numerical low rank nature of spatially blocked unknowns using the Adaptive Cross Approximation for compressing the rank deficient blocks of the system Z matrix, the L and U factors, the right hand side forcing function and the final current solution. This compressed matrix solution is applied to a frequency domain EM solution of Maxwell's equations using standard Method of Moments approach. Compressed matrix storage and operations count leads to orders of magnitude reduction in memory and run time.
Integral Education: New Directions for Higher Learning. SUNY Series in Integral Theory
ERIC Educational Resources Information Center
Esbjorn-Hargens, Sean, Ed.; Reams, Jonathan, Ed.; Gunnlaugson, Olen, Ed.
2010-01-01
The educational challenges faced today are driving us toward a new step in the evolution of educational theory and practice. Educators are called to go beyond simply presenting alternatives, to integrating the best of mainstream and alternative approaches and taking them to the next level. "Integral Education" accomplishes this by bringing…
Psychiatric Advance Directives and Social Workers: An Integrative Review
Van Dorn, Richard A.; Scheyett, Anna; Swanson, Jeffrey W.; Swartz, Marvin S.
2013-01-01
Psychiatric Advance Directives (PADs) are legal documents that allow individuals to express their wishes for future psychiatric care and to authorize a legally appointed proxy to make decisions on their behalf during incapacitating crises. PADs are viewed as an alternative to the coercive interventions that sometimes accompany mental health crises for persons with mental illness. Insofar as coercive interventions can abridge clients’ autonomy and self-determination -- values supported by the Profession’s Code of Ethics -- social workers have a vested interest in finding ways to reduce coercion and increase autonomy and self-determination in their practice. However, PADs are also viewed as having the potential to positively affect a variety of other clinical outcomes, including but not limited to treatment engagement, treatment satisfaction, and working alliance. This article reviews the clinical and legal history of PADs and empirical evidence for their implementation and effectiveness. Despite what should be an inherent interest in PADs, and the fact that laws authorizing PADs have proliferated in the past decade, there is little theoretical or empirical research in the social work literature. PMID:20408357
Integrating task-directed planning with reactive object recognition
NASA Astrophysics Data System (ADS)
Dickinson, Sven J.; Stevenson, Suzanne; Amdur, Eugene; Tsotsos, John K.; Olsson, Lars
1993-08-01
We describe a robot vision system that achieves complex object recognition with two layers of behaviors, performing the tasks of planning and object recognition, respectively. The recognition layer is a pipeline in which successive stages take in images from a stereo head, recover relevant features, build intermediate representations, and deposit 3-D objects into a world model. Each stage is an independent process that reacts automatically to output from the previous stage. This reactive system operates continuously and autonomously to construct the robot's 3-D model of the environment. Sitting above the recognition pipeline is the planner which is responsible for populating the world model with objects that satisfy the high-level goals of the system. For example, upon examination of the world model, the planner can decide to direct the head to another location, gating new images into the recognition pipeline, causing new objects to be deposited into the world model. Alternatively, the planner can alter the recognition behavior of the pipeline so that objects of a certain type or at a certain location appear in the world model.
Method to directly radiolabel antibodies for diagnostic imaging and therapy
Thakur, Mathew L.
1991-01-01
The invention is a novel method and kit for directly radiolabeling proteins such as antibodies or antibody fragments for diagnostic and therapeutic purposes. The method comprises incubating a protein-containing solution with a solution of sodium ascorbate; adding a required quantity of reduced radionuclide to the incubated protein. A kit is also provided wherein the protein and/or reducing agents may be in lyophilized form.
Method to directly radiolabel antibodies for diagnostic imaging and therapy
Thakur, Mathew L.
1994-01-01
The invention is a novel method and kit for directly radiolabeling proteins such as antibodies or antibody fragments for diagnostic and therapeutic purposes. The method comprises incubating a protein-containing solution with a solution of sodium ascorbate; adding a required quantity of reduced radionuclide to the incubated protein. A kit is also provided wherein the protein and/or reducing agents may be in lyophilized form.
Advances and future directions of research on spectral methods
NASA Technical Reports Server (NTRS)
Patera, A. T.
1986-01-01
Recent advances in spectral methods are briefly reviewed and characterized with respect to their convergence and computational complexity. Classical finite element and spectral approaches are then compared, and spectral element (or p-type finite element) approximations are introduced. The method is applied to the full Navier-Stokes equations, and examples are given of the application of the technique to several transitional flows. Future directions of research in the field are outlined.
Direct current uninterruptible power supply method and system
Sinha, Gautam
2003-12-02
A method and system are described for providing a direct current (DC) uninterruptible power supply with the method including, for example: continuously supplying fuel to a turbine; converting mechanical power from the turbine into alternating current (AC) electrical power; converting the AC electrical power to DC power within a predetermined voltage level range; supplying the DC power to a load; and maintaining a DC load voltage within the predetermined voltage level range by adjusting the amount of fuel supplied to the turbine.
Integrated method for chaotic time series analysis
Hively, L.M.; Ng, E.G.
1998-09-29
Methods and apparatus for automatically detecting differences between similar but different states in a nonlinear process monitor nonlinear data are disclosed. Steps include: acquiring the data; digitizing the data; obtaining nonlinear measures of the data via chaotic time series analysis; obtaining time serial trends in the nonlinear measures; and determining by comparison whether differences between similar but different states are indicated. 8 figs.
Integrated method for chaotic time series analysis
Hively, Lee M.; Ng, Esmond G.
1998-01-01
Methods and apparatus for automatically detecting differences between similar but different states in a nonlinear process monitor nonlinear data. Steps include: acquiring the data; digitizing the data; obtaining nonlinear measures of the data via chaotic time series analysis; obtaining time serial trends in the nonlinear measures; and determining by comparison whether differences between similar but different states are indicated.
Integrating Formal Methods and Testing 2002
NASA Technical Reports Server (NTRS)
Cukic, Bojan
2002-01-01
Traditionally, qualitative program verification methodologies and program testing are studied in separate research communities. None of them alone is powerful and practical enough to provide sufficient confidence in ultra-high reliability assessment when used exclusively. Significant advances can be made by accounting not only tho formal verification and program testing. but also the impact of many other standard V&V techniques, in a unified software reliability assessment framework. The first year of this research resulted in the statistical framework that, given the assumptions on the success of the qualitative V&V and QA procedures, significantly reduces the amount of testing needed to confidently assess reliability at so-called high and ultra-high levels (10-4 or higher). The coming years shall address the methodologies to realistically estimate the impacts of various V&V techniques to system reliability and include the impact of operational risk to reliability assessment. Combine formal correctness verification, process and product metrics, and other standard qualitative software assurance methods with statistical testing with the aim of gaining higher confidence in software reliability assessment for high-assurance applications. B) Quantify the impact of these methods on software reliability. C) Demonstrate that accounting for the effectiveness of these methods reduces the number of tests needed to attain certain confidence level. D) Quantify and justify the reliability estimate for systems developed using various methods.
One directional polarized neutron reflectometry with optimized reference layer method
Masoudi, S. Farhad; Jahromi, Saeed S.
2012-09-01
In the past decade, several neutron reflectometry methods for determining the modulus and phase of the complex reflection coefficient of an unknown multilayer thin film have been worked out among which the method of variation of surroundings and reference layers are of highest interest. These methods were later modified for measurement of the polarization of the reflected beam instead of the measurement of the intensities. In their new architecture, these methods not only suffered from the necessity of change of experimental setup but also another difficulty was added to their experimental implementations. This deficiency was related to the limitations of the technology of the neutron reflectometers that could only measure the polarization of the reflected neutrons in the same direction as the polarization of the incident beam. As the instruments are limited, the theory has to be optimized so that the experiment could be performed. In a recent work, we developed the method of variation of surroundings for one directional polarization analysis. In this new work, the method of reference layer with polarization analysis has been optimized to determine the phase and modulus of the unknown film with measurement of the polarization of the reflected neutrons in the same direction as the polarization of the incident beam.
Unsaturated hydraulic parameters determined from direct and indirect methods
Flint, Lorraine E.; Hudson, David B.; Flint, Alan L.
1997-10-22
Hydraulic parameters are required for numerical simulations of unsaturated flow at Yucca Mountain, a vertically heterogeneous volcanic site for a potential high-level waste repository in the desert southwest. In this paper, direct measurements of the unsaturated hydraulic conductivity using a centrifuge with a specialized rotor are compared to those estimated using a predictive conductivity equation and two methods of measuring moisture retention.
Method to directly radiolabel antibodies for diagnostic imaging and therapy
Thakur, M.L.
1991-04-30
This patent describes a method for directly labeling proteins with radionuclides for use in diagnostic imaging and therapy. It comprises: the steps of incubating a protein-containing solution with a solution of sodium ascorbate; adding a required quantity of reduced radionuclide to the incubated protein-containing solution and incubating.
NASA Astrophysics Data System (ADS)
Meng, Yang; Gao, Shesheng; Zhong, Yongmin; Hu, Gaoge; Subic, Aleksandar
2016-03-01
The use of the direct filtering approach for INS/GNSS integrated navigation introduces nonlinearity into the system state equation. As the unscented Kalman filter (UKF) is a promising method for nonlinear problems, an obvious solution is to incorporate the UKF concept in the direct filtering approach to address the nonlinearity involved in INS/GNSS integrated navigation. However, the performance of the standard UKF is dependent on the accurate statistical characterizations of system noise. If the noise distributions of inertial instruments and GNSS receivers are not appropriately described, the standard UKF will produce deteriorated or even divergent navigation solutions. This paper presents an adaptive UKF with noise statistic estimator to overcome the limitation of the standard UKF. According to the covariance matching technique, the innovation and residual sequences are used to determine the covariance matrices of the process and measurement noises. The proposed algorithm can estimate and adjust the system noise statistics online, and thus enhance the adaptive capability of the standard UKF. Simulation and experimental results demonstrate that the performance of the proposed algorithm is significantly superior to that of the standard UKF and adaptive-robust UKF under the condition without accurate knowledge on system noise, leading to improved navigation precision.
Shape integral method for magnetospheric shapes. [boundary layer calculations
NASA Technical Reports Server (NTRS)
Michel, F. C.
1979-01-01
A method is developed for calculating the shape of any magnetopause to arbitrarily high precision. The method uses an integral equation which is evaluated for a trial shape. The resulting values of the integral equation as a function of auxiliary variables indicate how close one is to the desired solution. A variational method can then be used to improve the trial shape. Some potential applications are briefly mentioned.
Intentional Forgetting of Actions: Comparison of List-Method and Item-Method Directed Forgetting
ERIC Educational Resources Information Center
Sahakyan, Lili; Foster, Nathaniel L.
2009-01-01
Performing action phrases (subject-performed tasks, SPTs) leads to better memory than verbal learning instructions (verbal tasks, VTs). In Experiments 1-3, the list-method directed forgetting design produced equivalent directed forgetting impairment for VTs and SPTs; however, directed forgetting enhancement emerged only for VTs, but not SPTs.…
Direct structural damping identification method using complex FRFs
NASA Astrophysics Data System (ADS)
Arora, Vikas
2015-03-01
Most of the identification methods are based only on the viscous damping model and uses modal data. In this paper, a new FRF-based direct structural damping identification method is proposed. The proposed method is a direct method and identifies structural damping matrix explicitly. As the new method is a FRF-based method, it overcomes the problem of closely spaced modes for damping identification. The accuracy of identified structural damping matrix depends upon the accuracy of finite element model. In this paper, FRF-based model updating method is used to obtain accurate mass and stiffness matrices. Thus, the procedure to obtain accurate structural damping matrix is a two-step procedure. In the first step, mass and stiffness matrices are updated and in the second step, structural damping matrix is identified using updated mass and stiffness matrices, which are obtained in the previous step. The effectiveness of the new method is demonstrated by three numerical examples and one experimental example. The numerical studies of lumped mass system, fixed-fixed beam and L-shaped frame structure are carried out. The effects of coordinate incompleteness, ill-conditioning and robustness of method under presence of noise are investigated. The proposed method is able to predict FRFs accurately for the frequency range covering the modes considered. However, beyond the considered modes, the predicted FRFs do not match the experimental FRFs. It is suggested in this work that ill-conditioning problem should be dealt by considering all the modes in the frequency range of interest. The performance of the proposed method is investigated for cases of light, medium and heavily damped structures. The numerical studies are followed by experimental case study of cantilever beam structure. The effectiveness of the proposed method is evaluated by comparing the predicted and the experimental FRFs. The results have shown that the proposed method is able to predict accurately the
Damping identification in frequency domain using integral method
NASA Astrophysics Data System (ADS)
Guo, Zhiwei; Sheng, Meiping; Ma, Jiangang; Zhang, Wulin
2015-03-01
A new method for damping identification of linear system in frequency domain is presented, by using frequency response function (FRF) with integral method. The FRF curve is firstly transformed to other type of frequency-related curve by changing the representations of horizontal and vertical axes. For the newly constructed frequency-related curve, integral is conducted and the area forming from the new curve is used to determine the damping. Three different methods based on integral are proposed in this paper, which are called FDI-1, FDI-2 and FDI-3 method, respectively. For a single degree of freedom (Sdof) system, the formulated relation of each method between integrated area and loss factor is derived theoretically. The numeral simulation and experiment results show that, the proposed integral methods have high precision, strong noise resistance and are very stable in repeated measurements. Among the three integral methods, FDI-3 method is the most recommended because of its higher accuracy and simpler algorithm. The new methods are limited to linear system in which modes are well separated, and for closely spaced mode system, mode decomposition process should be conducted firstly.
Method for observing phase objects without halos or directional shadows.
Suzuki, Yoshimasa; Kajitani, Kazuo; Ohde, Hisashi
2015-03-01
A new microscopy method for observing phase objects without halos or directional shadows is proposed. The method is based on transformation of the surface profile of phase objects into a light intensity pattern. The key optical element is an annular aperture at the front focal plane of a condenser. The light flux passing through the annular aperture is changed by the specimen's surface profile and then passes through an objective and contributes to image formation. Theory and experimental results are presented. Phase images of induced pluripotent stem (iPS) cells with clear outlines were obtained with this method.
Direct LSC method for measurements of biofuels in fuel.
Krištof, Romana; Logar, Jasmina Kožar
2013-07-15
Direct liquid scintillation counting (LSC) for quantification of biofuels content in fuels was implemented and validated on three liquid fossil fuel matrices-ethanol, gasoline and diesel. Fatty acid methyl esters (FAMEs), hydrogenated vegetable oils (HVO) and bio-ethanol were used as biofuels. The method is applicable in the range up to 100% for all tested combinations of bio components. The sensitivity and precision of the method are suitable for determination of bio component content in the blends which is appearing on the global market. The method does not require special equipment for sample preparation.
Lean direct wall fuel injection method and devices
NASA Technical Reports Server (NTRS)
Choi, Kyung J. (Inventor); Tacina, Robert (Inventor)
2000-01-01
A fuel combustion chamber, and a method of and a nozzle for mixing liquid fuel and air in the fuel combustion chamber in lean direct injection combustion for advanced gas turbine engines, including aircraft engines. Liquid fuel in a form of jet is injected directly into a cylindrical combustion chamber from the combustion chamber wall surface in a direction opposite to the direction of the swirling air at an angle of from about 50.degree. to about 60.degree. with respect to a tangential line of the cylindrical combustion chamber and at a fuel-lean condition, with a liquid droplet momentum to air momentum ratio in the range of from about 0.05 to about 0.12. Advanced gas turbines benefit from lean direct wall injection combustion. The lean direct wall injection technique of the present invention provides fast, uniform, well-stirred mixing of fuel and air. In addition, in order to further improve combustion, the fuel can be injected at a venturi located in the combustion chamber at a point adjacent the air swirler.
Exponential Methods for the Time Integration of Schroedinger Equation
Cano, B.; Gonzalez-Pachon, A.
2010-09-30
We consider exponential methods of second order in time in order to integrate the cubic nonlinear Schroedinger equation. We are interested in taking profit of the special structure of this equation. Therefore, we look at symmetry, symplecticity and approximation of invariants of the proposed methods. That will allow to integrate till long times with reasonable accuracy. Computational efficiency is also our aim. Therefore, we make numerical computations in order to compare the methods considered and so as to conclude that explicit Lawson schemes projected on the norm of the solution are an efficient tool to integrate this equation.
A multilevel finite element method for Fredholm integral eigenvalue problems
NASA Astrophysics Data System (ADS)
Xie, Hehu; Zhou, Tao
2015-12-01
In this work, we proposed a multigrid finite element (MFE) method for solving the Fredholm integral eigenvalue problems. The main motivation for such studies is to compute the Karhunen-Loève expansions of random fields, which play an important role in the applications of uncertainty quantification. In our MFE framework, solving the eigenvalue problem is converted to doing a series of integral iterations and eigenvalue solving in the coarsest mesh. Then, any existing efficient integration scheme can be used for the associated integration process. The error estimates are provided, and the computational complexity is analyzed. It is noticed that the total computational work of our method is comparable with a single integration step in the finest mesh. Several numerical experiments are presented to validate the efficiency of the proposed numerical method.
A Rationale for Mixed Methods (Integrative) Research Programmes in Education
ERIC Educational Resources Information Center
Niaz, Mansoor
2008-01-01
Recent research shows that research programmes (quantitative, qualitative and mixed) in education are not displaced (as suggested by Kuhn) but rather lead to integration. The objective of this study is to present a rationale for mixed methods (integrative) research programs based on contemporary philosophy of science (Lakatos, Giere, Cartwright,…
A novel prototyping method for die-level monolithic integration of MEMS above-IC
NASA Astrophysics Data System (ADS)
Cicek, Paul-Vahe; Zhang, Qing; Saha, Tanmoy; Mahdavi, Sareh; Allidina, Karim; Nabki, Frederic; El Gamal, Mourad
2013-06-01
This work presents a convenient and versatile prototyping method for integrating surface-micromachined microelectromechanical systems (MEMS) directly above IC electronics, at the die level. Such localized implementation helps reduce development costs associated with the acquisition of full-sized semiconductor wafers. To demonstrate the validity of this method, variants of an IC-compatible surface-micromachining MEMS process are used to build different MEMS devices above a commercial transimpedance amplifier chip. Subsequent functional assessments for both the electronics and the MEMS indicate that the integration is successful, validating the prototyping methodology presented in this work, as well as the suitability of the selected MEMS technology for above-IC integration.
Mutant fatty acid desaturase and methods for directed mutagenesis
Shanklin, John; Whittle, Edward J.
2008-01-29
The present invention relates to methods for producing fatty acid desaturase mutants having a substantially increased activity towards substrates with fewer than 18 carbon atom chains relative to an unmutagenized precursor desaturase having an 18 carbon chain length specificity, the sequences encoding the desaturases and to the desaturases that are produced by the methods. The present invention further relates to a method for altering a function of a protein, including a fatty acid desaturase, through directed mutagenesis involving identifying candidate amino acid residues, producing a library of mutants of the protein by simultaneously randomizing all amino acid candidates, and selecting for mutants which exhibit the desired alteration of function. Candidate amino acids are identified by a combination of methods. Enzymatic, binding, structural and other functions of proteins can be altered by the method.
Decoupled direct method for sensitivity analysis in combustion kinetics
NASA Technical Reports Server (NTRS)
Radhakrishnan, Krishnan
1987-01-01
An efficient, decoupled direct method for calculating the first order sensitivity coefficients of homogeneous, batch combustion kinetic rate equations is presented. In this method the ordinary differential equations for the sensitivity coefficients are solved separately from , but sequentially with, those describing the combustion chemistry. The ordinary differential equations for the thermochemical variables are solved using an efficient, implicit method (LSODE) that automatically selects the steplength and order for each solution step. The solution procedure for the sensitivity coefficients maintains accuracy and stability by using exactly the same steplengths and numerical approximations. The method computes sensitivity coefficients with respect to any combination of the initial values of the thermochemical variables and the three rate constant parameters for the chemical reactions. The method is illustrated by application to several simple problems and, where possible, comparisons are made with exact solutions and those obtained by other techniques.
Direct simulation Monte Carlo method with a focal mechanism algorithm
NASA Astrophysics Data System (ADS)
Rachman, Asep Nur; Chung, Tae Woong; Yoshimoto, Kazuo; Yun, Sukyoung
2015-01-01
To simulate the observation of the radiation pattern of an earthquake, the direct simulation Monte Carlo (DSMC) method is modified by implanting a focal mechanism algorithm. We compare the results of the modified DSMC method (DSMC-2) with those of the original DSMC method (DSMC-1). DSMC-2 shows more or similarly reliable results compared to those of DSMC-1, for events with 12 or more recorded stations, by weighting twice for hypocentral distance of less than 80 km. Not only the number of stations, but also other factors such as rough topography, magnitude of event, and the analysis method influence the reliability of DSMC-2. The most reliable result by DSMC-2 is obtained by the best azimuthal coverage by the largest number of stations. The DSMC-2 method requires shorter time steps and a larger number of particles than those of DSMC-1 to capture a sufficient number of arrived particles in the small-sized receiver.
Method for observing phase objects without halos and directional shadows
NASA Astrophysics Data System (ADS)
Suzuki, Yoshimasa; Kajitani, Kazuo; Ohde, Hisashi
2015-03-01
A new microscopy method for observing phase objects without halos and directional shadows is proposed. The key optical element is an annular aperture at the front focal plane of a condenser with a larger diameter than those used in standard phase contrast microscopy. The light flux passing through the annular aperture is changed by the specimen's surface profile and then passes through an objective and contributes to image formation. This paper presents essential conditions for realizing the method. In this paper, images of colonies formed by induced pluripotent stem (iPS) cells using this method are compared with the conventional phase contrast method and the bright-field method when the NA of the illumination is small to identify differences among these techniques. The outlines of the iPS cells are clearly visible with this method, whereas they are not clearly visible due to halos when using the phase contrast method or due to weak contrast when using the bright-field method. Other images using this method are also presented to demonstrate a capacity of this method: a mouse ovum and superimposition of several different images of mouse iPS cells.
Method for determining shear direction using liquid crystal coatings
NASA Technical Reports Server (NTRS)
Reda, Daniel C.
1995-01-01
A method is provided for determining shear direction wherein a beam of white light is directed onto the surface of a liquid crystal coating to cause the white light to be dispersed (reflected) from the surface in a spectrum having bands of different colors in a fixed spatial 2 (angular) sequence. The system is calibrated by locating an observer, e.g., a video and movie camera, such that a particular color band (preferably at or near the center of the reflected spectrum) is observed to thereby provide a reference color band. Because the application of shear causes either clockwise or counterclockwise rotation of the reflected spectrum dependent on the direction of the shear, a determination is then made of the reflected color band observed by the observer when the surface of the liquid crystal is subjected to shear to thereby determine the direction of the shear based on the directional (rotation) relation of the observed color band with respect to the reference color band in the spatial sequence of color bands.
Improving the Accuracy of the Boundary Integral Method Based on the Helmholtz Integral
NASA Technical Reports Server (NTRS)
Koopmann, G. H.; Brod, K.
1985-01-01
Several recent papers in the literature have been based on various forms of the Helmholtz integral to compute the radiation fields of vibrating bodies. The surface integral form is given. The symbols of P,R micron, rho,G,R,V, and S micron are acoustic pressure, source coordinate, angular frequency, fluid density, Green function, field coordinate, surface velocity and body surface respectively. A discretized form of the surface integral is also given. Solutions to the surface integral are complicated with the singularity of the Green function at R=R micron and with the uniqueness problem at interior eigen frequencies of the enclosed space. The use of the interior integral circumvents the singularity problem since the field points are chosen in the interior space of the vibrating body where a zero pressure condition exists. The interior integral form is given. The method to improve the accuracy is detailed. Examples of the method is presented for a variety of radiators.
Two-dimensional location and direction estimating method.
Haga, Teruhiro; Tsukamoto, Sosuke; Hoshino, Hiroshi
2008-01-01
In this paper, a method of estimating both the position and the rotation angle of an object on a measurement stage was proposed. The system utilizes the radio communication technology and the directivity of an antenna. As a prototype system, a measurement stage (a circle 240mm in diameter) with 36 antennas that placed in each 10 degrees was developed. Two transmitter antennas are settled in a right angle on the stage as the target object, and the position and the rotation angle is estimated by measuring efficiency of the radio communication of each 36 antennas. The experimental result revealed that even when the estimated location is not so accurate (about a 30 mm error), the rotation angle is accurately estimated (about 2.33 degree error on average). The result suggests that the proposed method will be useful for estimating the location and the direction of an object.
Ran, Changyan; Cheng, Xianghong
2016-01-01
This paper presents a direct and non-singular approach based on an unscented Kalman filter (UKF) for the integration of strapdown inertial navigation systems (SINSs) with the aid of velocity. The state vector includes velocity and Euler angles, and the system model contains Euler angle kinematics equations. The measured velocity in the body frame is used as the filter measurement. The quaternion nonlinear equality constraint is eliminated, and the cross-noise problem is overcome. The filter model is simple and easy to apply without linearization. Data fusion is performed by an UKF, which directly estimates and outputs the navigation information. There is no need to process navigation computation and error correction separately because the navigation computation is completed synchronously during the filter time updating. In addition, the singularities are avoided with the help of the dual-Euler method. The performance of the proposed approach is verified by road test data from a land vehicle equipped with an odometer aided SINS, and a singularity turntable test is conducted using three-axis turntable test data. The results show that the proposed approach can achieve higher navigation accuracy than the commonly-used indirect approach, and the singularities can be efficiently removed as the result of dual-Euler method. PMID:27598169
Ran, Changyan; Cheng, Xianghong
2016-09-02
This paper presents a direct and non-singular approach based on an unscented Kalman filter (UKF) for the integration of strapdown inertial navigation systems (SINSs) with the aid of velocity. The state vector includes velocity and Euler angles, and the system model contains Euler angle kinematics equations. The measured velocity in the body frame is used as the filter measurement. The quaternion nonlinear equality constraint is eliminated, and the cross-noise problem is overcome. The filter model is simple and easy to apply without linearization. Data fusion is performed by an UKF, which directly estimates and outputs the navigation information. There is no need to process navigation computation and error correction separately because the navigation computation is completed synchronously during the filter time updating. In addition, the singularities are avoided with the help of the dual-Euler method. The performance of the proposed approach is verified by road test data from a land vehicle equipped with an odometer aided SINS, and a singularity turntable test is conducted using three-axis turntable test data. The results show that the proposed approach can achieve higher navigation accuracy than the commonly-used indirect approach, and the singularities can be efficiently removed as the result of dual-Euler method.
Ran, Changyan; Cheng, Xianghong
2016-01-01
This paper presents a direct and non-singular approach based on an unscented Kalman filter (UKF) for the integration of strapdown inertial navigation systems (SINSs) with the aid of velocity. The state vector includes velocity and Euler angles, and the system model contains Euler angle kinematics equations. The measured velocity in the body frame is used as the filter measurement. The quaternion nonlinear equality constraint is eliminated, and the cross-noise problem is overcome. The filter model is simple and easy to apply without linearization. Data fusion is performed by an UKF, which directly estimates and outputs the navigation information. There is no need to process navigation computation and error correction separately because the navigation computation is completed synchronously during the filter time updating. In addition, the singularities are avoided with the help of the dual-Euler method. The performance of the proposed approach is verified by road test data from a land vehicle equipped with an odometer aided SINS, and a singularity turntable test is conducted using three-axis turntable test data. The results show that the proposed approach can achieve higher navigation accuracy than the commonly-used indirect approach, and the singularities can be efficiently removed as the result of dual-Euler method. PMID:27598169
A New Power Flow Tracing Method Based on Directed Circuit
NASA Astrophysics Data System (ADS)
Zhang, Weimin; Guo, Xiaojing; Liu, Yaonian; Ni, Defu; Wang, Lina; Jia, Yanbing
In this paper, a power-sharing principle is proposed, base on the generation of the directed path. The principle is used to calculate the contributions of individual generators and loads to line flows and the real power transfer among individual generators and loads that are significant to transmission open access. From the IEEE 14-bus power systems, the effectiveness and availability of the method are verified.
Maximum patch method for directional dark matter detection
Henderson, Shawn; Monroe, Jocelyn; Fisher, Peter
2008-07-01
Present and planned dark matter detection experiments search for WIMP-induced nuclear recoils in poorly known background conditions. In this environment, the maximum gap statistical method provides a way of setting more sensitive cross section upper limits by incorporating known signal information. We give a recipe for the numerical calculation of upper limits for planned directional dark matter detection experiments, that will measure both recoil energy and angle, based on the gaps between events in two-dimensional phase space.
High order integral equation method for diffraction gratings.
Lu, Wangtao; Lu, Ya Yan
2012-05-01
Conventional integral equation methods for diffraction gratings require lattice sum techniques to evaluate quasi-periodic Green's functions. The boundary integral equation Neumann-to-Dirichlet map (BIE-NtD) method in Wu and Lu [J. Opt. Soc. Am. A 26, 2444 (2009)], [J. Opt. Soc. Am. A 28, 1191 (2011)] is a recently developed integral equation method that avoids the quasi-periodic Green's functions and is relatively easy to implement. In this paper, we present a number of improvements for this method, including a revised formulation that is more stable numerically, and more accurate methods for computing tangential derivatives along material interfaces and for matching boundary conditions with the homogeneous top and bottom regions. Numerical examples indicate that the improved BIE-NtD map method achieves a high order of accuracy for in-plane and conical diffractions of dielectric gratings.
Integrated resonant micro-optical gyroscope and method of fabrication
Vawter, G. Allen; Zubrzycki, Walter J.; Guo, Junpeng; Sullivan, Charles T.
2006-09-12
An integrated optic gyroscope is disclosed which is based on a photonic integrated circuit (PIC) having a bidirectional laser source, a pair of optical waveguide phase modulators and a pair of waveguide photodetectors. The PIC can be connected to a passive ring resonator formed either as a coil of optical fiber or as a coiled optical waveguide. The lasing output from each end of the bidirectional laser source is phase modulated and directed around the passive ring resonator in two counterpropagating directions, with a portion of the lasing output then being detected to determine a rotation rate for the integrated optical gyroscope. The coiled optical waveguide can be formed on a silicon, glass or quartz substrate with a silicon nitride core and a silica cladding, while the PIC includes a plurality of III V compound semiconductor layers including one or more quantum well layers which are disordered in the phase modulators and to form passive optical waveguides.
Improvement of high-order least-squares integration method for stereo deflectometry.
Ren, Hongyu; Gao, Feng; Jiang, Xiangqian
2015-12-01
Stereo deflectometry is defined as measurement of the local slope of specular surfaces by using two CCD cameras as detectors and one LCD screen as a light source. For obtaining 3D topography, integrating the calculated slope data is needed. Currently, a high-order finite-difference-based least-squares integration (HFLI) method is used to improve the integration accuracy. However, this method cannot be easily implemented in circular domain or when gradient data are incomplete. This paper proposes a modified easy-implementation integration method based on HFLI (EI-HFLI), which can work in arbitrary domains, and can directly and conveniently handle incomplete gradient data. To carry out the proposed algorithm in a practical stereo deflectometry measurement, gradients are calculated in both CCD frames, and then are mixed together as original data to be meshed into rectangular grids format. Simulation and experiments show this modified method is feasible and can work efficiently. PMID:26836684
Mixed time integration methods for transient thermal analysis of structures
NASA Technical Reports Server (NTRS)
Liu, W. K.
1982-01-01
The computational methods used to predict and optimize the thermal structural behavior of aerospace vehicle structures are reviewed. In general, two classes of algorithms, implicit and explicit, are used in transient thermal analysis of structures. Each of these two methods has its own merits. Due to the different time scales of the mechanical and thermal responses, the selection of a time integration method can be a different yet critical factor in the efficient solution of such problems. Therefore mixed time integration methods for transient thermal analysis of structures are being developed. The computer implementation aspects and numerical evaluation of these mixed time implicit-explicit algorithms in thermal analysis of structures are presented. A computationally useful method of estimating the critical time step for linear quadrilateral element is also given. Numerical tests confirm the stability criterion and accuracy characteristics of the methods. The superiority of these mixed time methods to the fully implicit method or the fully explicit method is also demonstrated.
An integrated lean-methods approach to hospital facilities redesign.
Nicholas, John
2012-01-01
Lean production methods for eliminating waste and improving processes in manufacturing are now being applied in healthcare. As the author shows, the methods are appropriate for redesigning hospital facilities. When used in an integrated manner and employing teams of mostly clinicians, the methods produce facility designs that are custom-fit to patient needs and caregiver work processes, and reduce operational costs. The author reviews lean methods and an approach for integrating them in the redesign of hospital facilities. A case example of the redesign of an emergency department shows the feasibility and benefits of the approach.
An integrated lean-methods approach to hospital facilities redesign.
Nicholas, John
2012-01-01
Lean production methods for eliminating waste and improving processes in manufacturing are now being applied in healthcare. As the author shows, the methods are appropriate for redesigning hospital facilities. When used in an integrated manner and employing teams of mostly clinicians, the methods produce facility designs that are custom-fit to patient needs and caregiver work processes, and reduce operational costs. The author reviews lean methods and an approach for integrating them in the redesign of hospital facilities. A case example of the redesign of an emergency department shows the feasibility and benefits of the approach. PMID:22671435
A dynamic integrated fault diagnosis method for power transformers.
Gao, Wensheng; Bai, Cuifen; Liu, Tong
2015-01-01
In order to diagnose transformer fault efficiently and accurately, a dynamic integrated fault diagnosis method based on Bayesian network is proposed in this paper. First, an integrated fault diagnosis model is established based on the causal relationship among abnormal working conditions, failure modes, and failure symptoms of transformers, aimed at obtaining the most possible failure mode. And then considering the evidence input into the diagnosis model is gradually acquired and the fault diagnosis process in reality is multistep, a dynamic fault diagnosis mechanism is proposed based on the integrated fault diagnosis model. Different from the existing one-step diagnosis mechanism, it includes a multistep evidence-selection process, which gives the most effective diagnostic test to be performed in next step. Therefore, it can reduce unnecessary diagnostic tests and improve the accuracy and efficiency of diagnosis. Finally, the dynamic integrated fault diagnosis method is applied to actual cases, and the validity of this method is verified.
A Dynamic Integrated Fault Diagnosis Method for Power Transformers
Gao, Wensheng; Liu, Tong
2015-01-01
In order to diagnose transformer fault efficiently and accurately, a dynamic integrated fault diagnosis method based on Bayesian network is proposed in this paper. First, an integrated fault diagnosis model is established based on the causal relationship among abnormal working conditions, failure modes, and failure symptoms of transformers, aimed at obtaining the most possible failure mode. And then considering the evidence input into the diagnosis model is gradually acquired and the fault diagnosis process in reality is multistep, a dynamic fault diagnosis mechanism is proposed based on the integrated fault diagnosis model. Different from the existing one-step diagnosis mechanism, it includes a multistep evidence-selection process, which gives the most effective diagnostic test to be performed in next step. Therefore, it can reduce unnecessary diagnostic tests and improve the accuracy and efficiency of diagnosis. Finally, the dynamic integrated fault diagnosis method is applied to actual cases, and the validity of this method is verified. PMID:25685841
Achieving Integration in Mixed Methods Designs—Principles and Practices
Fetters, Michael D; Curry, Leslie A; Creswell, John W
2013-01-01
Mixed methods research offers powerful tools for investigating complex processes and systems in health and health care. This article describes integration principles and practices at three levels in mixed methods research and provides illustrative examples. Integration at the study design level occurs through three basic mixed method designs—exploratory sequential, explanatory sequential, and convergent—and through four advanced frameworks—multistage, intervention, case study, and participatory. Integration at the methods level occurs through four approaches. In connecting, one database links to the other through sampling. With building, one database informs the data collection approach of the other. When merging, the two databases are brought together for analysis. With embedding, data collection and analysis link at multiple points. Integration at the interpretation and reporting level occurs through narrative, data transformation, and joint display. The fit of integration describes the extent the qualitative and quantitative findings cohere. Understanding these principles and practices of integration can help health services researchers leverage the strengths of mixed methods. PMID:24279835
Methods for biological data integration: perspectives and challenges
Gligorijević, Vladimir; Pržulj, Nataša
2015-01-01
Rapid technological advances have led to the production of different types of biological data and enabled construction of complex networks with various types of interactions between diverse biological entities. Standard network data analysis methods were shown to be limited in dealing with such heterogeneous networked data and consequently, new methods for integrative data analyses have been proposed. The integrative methods can collectively mine multiple types of biological data and produce more holistic, systems-level biological insights. We survey recent methods for collective mining (integration) of various types of networked biological data. We compare different state-of-the-art methods for data integration and highlight their advantages and disadvantages in addressing important biological problems. We identify the important computational challenges of these methods and provide a general guideline for which methods are suited for specific biological problems, or specific data types. Moreover, we propose that recent non-negative matrix factorization-based approaches may become the integration methodology of choice, as they are well suited and accurate in dealing with heterogeneous data and have many opportunities for further development. PMID:26490630
Explicit Integration of Extremely Stiff Reaction Networks: Partial Equilibrium Methods
Guidry, Mike W; Billings, J. J.; Hix, William Raphael
2013-01-01
In two preceding papers [1,2] we have shown that, when reaction networks are well removed from equilibrium, explicit asymptotic and quasi-steady-state approximations can give algebraically stabilized integration schemes that rival standard implicit methods in accuracy and speed for extremely stiff systems. However, we also showed that these explicit methods remain accurate but are no longer competitive in speed as the network approaches equilibrium. In this paper we analyze this failure and show that it is associated with the presence of fast equilibration timescales that neither asymptotic nor quasi-steady-state approximations are able to remove efficiently from the numerical integration. Based on this understanding, we develop a partial equilibrium method to deal effectively with the new partial equilibrium methods, give an integration scheme that plausibly can deal with the stiffest networks, even in the approach to equilibrium, with accuracy and speed competitive with that of implicit methods. Thus we demonstrate that algebraically stabilized explicit methods may offer alternatives to implicit integration of even extremely stiff systems, and that these methods may permit integration of much larger networks than have been feasible previously in a variety of fields.
The method of modular characteristic direction probabilities in MPACT
Liu, Z.; Kochunas, B.; Collins, B.; Downar, T.; Wu, H.
2013-07-01
The method of characteristic direction probabilities (CDP) is based on a modular ray tracing technique which combines the benefits of the collision probability method (CPM) and the method of characteristics (MOC). This past year CDP was implemented in the transport code MPACT for 2-D and 3-D transport calculations. By only coupling the fine mesh regions passed by the characteristic rays in the particular direction, the scale of the probabilities matrix is much smaller compared to the CPM. At the same time, the CDP has the same capacity of dealing with the complicated geometries with the MOC, because the same modular ray tracing techniques are used. Results from the C5G7 benchmark problems are given for different cases to show the accuracy and efficiency of the CDP compared to MOC. For the cases examined, the CDP and MOC methods were seen to differ in k{sub eff} by about 1-20 pcm, and the computational efficiency of the CDP appears to be better than the MOC for some problems. However, in other problems, particularly when the CDP matrices have to be recomputed from changing cross sections, the CDP does not perform as well. This indicates an area of future work. (authors)
NASA Technical Reports Server (NTRS)
Madsen, Niel K.
1992-01-01
Several new discrete surface integral (DSI) methods for solving Maxwell's equations in the time-domain are presented. These methods, which allow the use of general nonorthogonal mixed-polyhedral unstructured grids, are direct generalizations of the canonical staggered-grid finite difference method. These methods are conservative in that they locally preserve divergence or charge. Employing mixed polyhedral cells, (hexahedral, tetrahedral, etc.) these methods allow more accurate modeling of non-rectangular structures and objects because the traditional stair-stepped boundary approximations associated with the orthogonal grid based finite difference methods can be avoided. Numerical results demonstrating the accuracy of these new methods are presented.
Reliable Transition State Searches Integrated with the Growing String Method.
Zimmerman, Paul
2013-07-01
The growing string method (GSM) is highly useful for locating reaction paths connecting two molecular intermediates. GSM has often been used in a two-step procedure to locate exact transition states (TS), where GSM creates a quality initial structure for a local TS search. This procedure and others like it, however, do not always converge to the desired transition state because the local search is sensitive to the quality of the initial guess. This article describes an integrated technique for simultaneous reaction path and exact transition state search. This is achieved by implementing an eigenvector following optimization algorithm in internal coordinates with Hessian update techniques. After partial convergence of the string, an exact saddle point search begins under the constraint that the maximized eigenmode of the TS node Hessian has significant overlap with the string tangent near the TS. Subsequent optimization maintains connectivity of the string to the TS as well as locks in the TS direction, all but eliminating the possibility that the local search leads to the wrong TS. To verify the robustness of this approach, reaction paths and TSs are found for a benchmark set of more than 100 elementary reactions.
Engle, Mark A.; Olea, Ricardo A.; O'Keefe, Jennifer M. K.; Hower, James C.; Geboy, Nicholas J.
2013-01-01
Coal fires occur in nature spontaneously, contribute to increases in greenhouse gases, and emit atmospheric toxicants. Increasing interest in quantifying coal fire emissions has resulted in the adaptation and development of specialized approaches and adoption of numerical modeling techniques. Overview of these methods for direct estimation of diffuse gas emissions from coal fires is presented in this paper. Here we take advantage of stochastic Gaussian simulation to interpolate CO2 fluxes measured using a dynamic closed chamber at the Ruth Mullins coal fire in Perry County, Kentucky. This approach allows for preparing a map of diffuse gas emissions, one of the two primary ways that gases emanate from coal fires, and establishing the reliability of the study both locally and for the entire fire. Future research directions include continuous and automated sampling to improve quantification of gaseous coal fire emissions.
Directed self-assembly process integration: Fin patterning approaches and challenges
NASA Astrophysics Data System (ADS)
Sayan, Safak; Chan, B. T.; Gronheid, Roel; Van Roey, Frieda; Kim, Min-Soo; Williamson, Lance; Nealey, Paul
2014-03-01
Resolution requirements for photolithography have reached beyond the wavelength of light. Consequently, it is becoming increasingly complicated and expensive to further minimize feature dimensions as required to push the limits of Moore's law. EUV lithography has been the much anticipated solution; however, its insertion timing for High Volume Manufacturing is still an uncertainty due to source power and EUV mask infrastructure limitations. Extending the limits of 193nm immersion lithography requires pitch division using either Double Patterning Pitch Division (DPPD), and/or Spacer Based Pitch Division (SBPD) schemes (e.g. Hard mask image transfer methods (Double, Triple, Quadruple)). While these approaches reduce pitch, there is an associated risk/compromise of process complexity, and overlay accuracy budget issues. Directed Self Assembly (DSA) processes offer the promise of providing alternative ways to extend optical lithography cost-effectively for sub-10nm nodes and present itself as an alternative pitch division approach. As a result, DSA has gained increased momentum in recent years, as a means for extending optical lithography past its current limits. The availability of a DSA processing line can enable to further push the limits of 193nm immersion lithography and overcome some of the critical concerns for EUV lithography. Robust etch transfer of DSA patterns into commonly used device integration materials such as silicon, silicon nitride, and silicon dioxide had been previously demonstrated [1,2]. However DSA integration to CMOS process flows, including cut/keep structures to form fin arrays, is yet to be demonstrated on relevant film stacks (front-end-of-line device integration such as hard mask stacks, and STI stacks). Such a demonstration will confirm and reinforce its viability as a candidate for sub-10nm technology nodes.
Using MACSYMA to drive numerical methods to computer radiation integrals
Clark, B.A.
1986-01-01
Because the emission of thermal radiation is characterized by the Planck emission spectrum, a multigroup solution of the thermal-radiation transport equation demands the calculation of definite integrals of the Planck spectrum. In the past, many approximate methods have been used with varying degrees of accuracy and efficiency. This paper describes how a symbolic algebra package, in this case MACSYMA is used to develop new methods for accurately and efficiently evaluating multigroup Planck integrals. The advantage of using a symbolic algebra package is that the job of developing the new methods is accomplished more efficiently.
Application of integrated fluid-thermal-structural analysis methods
NASA Technical Reports Server (NTRS)
Wieting, Allan R.; Dechaumphai, Pramote; Bey, Kim S.; Thornton, Earl A.; Morgan, Ken
1988-01-01
Hypersonic vehicles operate in a hostile aerothermal environment which has a significant impact on their aerothermostructural performance. Significant coupling occurs between the aerodynamic flow field, structural heat transfer, and structural response creating a multidisciplinary interaction. Interfacing state-of-the-art disciplinary analysis methods is not efficient, hence interdisciplinary analysis methods integrated into a single aerothermostructural analyzer are needed. The NASA Langley Research Center is developing such methods in an analyzer called LIFTS (Langley Integrated Fluid-Thermal-Structural) analyzer. The evolution and status of LIFTS is reviewed and illustrated through applications.
Method and system of integrating information from multiple sources
Alford, Francine A.; Brinkerhoff, David L.
2006-08-15
A system and method of integrating information from multiple sources in a document centric application system. A plurality of application systems are connected through an object request broker to a central repository. The information may then be posted on a webpage. An example of an implementation of the method and system is an online procurement system.
A Comparison of Treatment Integrity Assessment Methods for Behavioral Intervention
ERIC Educational Resources Information Center
Koh, Seong A.
2010-01-01
The purpose of this study was to examine the similarity of outcomes from three different treatment integrity (TI) methods, and to identify the method which best corresponded to the assessment of a child's behavior. Six raters were recruited through individual contact via snowball sampling. A modified intervention component list and 19 video clips…
When Curriculum and Technology Meet: Technology Integration in Methods Courses
ERIC Educational Resources Information Center
Keeler, Christy G.
2008-01-01
Reporting on the results of an action research study, this manuscript provides examples of strategies used to integrate technology into a content methods course. The study used reflective teaching of a social studies methods course at a major Southwestern university in 10 course sections over a four-semester period. In alignment with the research…
Li, Shanzhi; Wang, Haoping; Tian, Yang; Aitouch, Abdel; Klein, John
2016-09-01
This paper presents an intelligent proportional-integral sliding mode control (iPISMC) for direct power control of variable speed-constant frequency wind turbine system. This approach deals with optimal power production (in the maximum power point tracking sense) under several disturbance factors such as turbulent wind. This controller is made of two sub-components: (i) an intelligent proportional-integral module for online disturbance compensation and (ii) a sliding mode module for circumventing disturbance estimation errors. This iPISMC method has been tested on FAST/Simulink platform of a 5MW wind turbine system. The obtained results demonstrate that the proposed iPISMC method outperforms the classical PI and intelligent proportional-integral control (iPI) in terms of both active power and response time.
Li, Shanzhi; Wang, Haoping; Tian, Yang; Aitouch, Abdel; Klein, John
2016-09-01
This paper presents an intelligent proportional-integral sliding mode control (iPISMC) for direct power control of variable speed-constant frequency wind turbine system. This approach deals with optimal power production (in the maximum power point tracking sense) under several disturbance factors such as turbulent wind. This controller is made of two sub-components: (i) an intelligent proportional-integral module for online disturbance compensation and (ii) a sliding mode module for circumventing disturbance estimation errors. This iPISMC method has been tested on FAST/Simulink platform of a 5MW wind turbine system. The obtained results demonstrate that the proposed iPISMC method outperforms the classical PI and intelligent proportional-integral control (iPI) in terms of both active power and response time. PMID:27346331
Directional radiation of Babinet-inverted optical nanoantenna integrated with plasmonic waveguide
Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Jeong Kim, Un; Hwang, Sung Woo; Park, Yeonsang; Lee, Chang-Won
2015-01-01
We present a Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide. Using an integrated nanoantenna, we can couple the plasmon guide mode in a metal-insulator-metal (MIM) structure into the resonant antenna feed directly. The resonantly excited feed slot then radiates to free space and generates a magnetic dipole-like far-field pattern. The coupling efficiency of the integrated nanoantenna is calculated as being approximately 19% using a three-dimensional finite-difference time-domain (3D FDTD) simulation. By adding an auxiliary groove structure along with the feed, the radiation direction can be controlled similar to an optical Yagi-Uda antenna. We also determine, both theoretically and experimentally, that groove depth plays a significant role to function groove structure as a reflector or a director. The demonstrated Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide can be used as a “plasmonic via” in plasmonic nanocircuits. PMID:26135115
A Fully Integrated Nanosystem of Semiconductor Nanowires for Direct Solar Water Splitting
Liu, Chong; Tang, Jinyao; Chen, HaoMing; Liu, Bin; Yang, Peidong
2013-02-21
Artificial photosynthesis, the biomimetic approach to converting sunlight?s energy directly into chemical fuels, aims to imitate nature by using an integrated system of nanostructures, each of which plays a specific role in the sunlight-to-fuel conversion process. Here we describe a fully integrated system of nanoscale photoelectrodes assembled from inorganic nanowires for direct solar water splitting. Similar to the photosynthetic system in a chloroplast, the artificial photosynthetic system comprises two semiconductor light absorbers with large surface area, an interfacial layer for charge transport, and spatially separated cocatalysts to facilitate the water reduction and oxidation. Under simulated sunlight, a 0.12percent solar-to-fuel conversion efficiency is achieved, which is comparable to that of natural photosynthesis. The result demonstrates the possibility of integrating material components into a functional system that mimics the nanoscopic integration in chloroplasts. It also provides a conceptual blueprint of modular design that allows incorporation of newly discovered components for improved performance.
A flexible importance sampling method for integrating subgrid processes
NASA Astrophysics Data System (ADS)
Raut, E. K.; Larson, V. E.
2016-01-01
Numerical models of weather and climate need to compute grid-box-averaged rates of physical processes such as microphysics. These averages are computed by integrating subgrid variability over a grid box. For this reason, an important aspect of atmospheric modeling is spatial integration over subgrid scales. The needed integrals can be estimated by Monte Carlo integration. Monte Carlo integration is simple and general but requires many evaluations of the physical process rate. To reduce the number of function evaluations, this paper describes a new, flexible method of importance sampling. It divides the domain of integration into eight categories, such as the portion that contains both precipitation and cloud, or the portion that contains precipitation but no cloud. It then allows the modeler to prescribe the density of sample points within each of the eight categories. The new method is incorporated into the Subgrid Importance Latin Hypercube Sampler (SILHS). The resulting method is tested on drizzling cumulus and stratocumulus cases. In the cumulus case, the sampling error can be considerably reduced by drawing more sample points from the region of rain evaporation.
A flexible importance sampling method for integrating subgrid processes
Raut, E. K.; Larson, V. E.
2016-01-29
Numerical models of weather and climate need to compute grid-box-averaged rates of physical processes such as microphysics. These averages are computed by integrating subgrid variability over a grid box. For this reason, an important aspect of atmospheric modeling is spatial integration over subgrid scales. The needed integrals can be estimated by Monte Carlo integration. Monte Carlo integration is simple and general but requires many evaluations of the physical process rate. To reduce the number of function evaluations, this paper describes a new, flexible method of importance sampling. It divides the domain of integration into eight categories, such as the portion that containsmore » both precipitation and cloud, or the portion that contains precipitation but no cloud. It then allows the modeler to prescribe the density of sample points within each of the eight categories. The new method is incorporated into the Subgrid Importance Latin Hypercube Sampler (SILHS). The resulting method is tested on drizzling cumulus and stratocumulus cases. In the cumulus case, the sampling error can be considerably reduced by drawing more sample points from the region of rain evaporation.« less
Holographic LEED: A direct method for surface crystallography
NASA Astrophysics Data System (ADS)
Vamvakas, John Athanasios
Since 1960's Low Energy Electron Diffraction (LEED) has been one of the most reliable methods for surface crystallography. It has solved hundreds of structures over the past 20-25 years and continues to be a powerful tool in the hands of crystallographers. Yet, the main disadvantage of the method is the fact that it is very time consuming. The programs that do the multiple scattering calculations can run literally for days! The key part of the method is the initial "guess" of a structure that will be close the one being seeked. A wrong guess would lead to huge amounts of wasted time and effort. We suggest a direct method that can give us a pretty good idea of the structure under determination. We call this method of ours: Holographic LEED (h-LEED) because it is based on the ideas of Dennis Gabor, the inventor of holography. The 3D images h-LEED reconstructs from LEED diffraction patterns can be reliably used to initialize LEED thus reducing the annoying computation time as well as the effort required by the crystallographer. We show that h-LEED produces good images for p(2× 2) reconstruction of adsorbed atoms by testing it on two adsorption systems: O/Ni(001) and K/Ni(001). The images were reconstructed from both diffuse LEED patterns from disordered adsorbates and superstructure Bragg spots from ordered adsorbates.
Direct field method for root biomass quantification in agroecosystems.
Frasier, Ileana; Noellemeyer, Elke; Fernández, Romina; Quiroga, Alberto
2016-01-01
The present article describes a field auger sampling method for row-crop root measurements. In agroecosystems where crops are planted in a specific design (row crops), sampling procedures for root biomass quantification need to consider the spatial variability of the root system. This article explains in detail how to sample and calculate root biomass considering the sampling position in the field and the differential weight of the root biomass in the inter-row compared to the crop row when expressing data per area unit. This method is highly reproducible in the field and requires no expensive equipment and/or special skills. It proposes to use a narrow auger thus reducing field labor with less destructive sampling, and decreases laboratory time because samples are smaller. The small sample size also facilitates the washing and root separation with tweezers. This method is suitable for either winter- or summer crop roots. •Description of a direct field method for row-crop root measurements.•Description of data calculation for total root-biomass estimation per unit area.•The proposed method is simple, less labor- and less time consuming. PMID:27630821
Retrieval practice can eliminate list method directed forgetting.
Abel, Magdalena; Bäuml, Karl-Heinz T
2016-01-01
It has recently been shown that retrieval practice can reduce memories' susceptibility to interference, like retroactive and proactive interference. In this study, we therefore examined whether retrieval practice can also reduce list method directed forgetting, a form of intentional forgetting that presupposes interference. In each of two experiments, subjects successively studied two lists of items. After studying each single list, subjects restudied the list items to enhance learning, or they were asked to recall the items. Following restudy or retrieval practice of list 1 items, subjects were cued to either forget the list or remember it for an upcoming final test. Experiment 1 employed a free-recall and Experiment 1 a cued-recall procedure on the final memory test. In both experiments, directed forgetting was present in the restudy condition but was absent in the retrieval-practice condition, indicating that retrieval practice can reduce or even eliminate this form of forgetting. The results are consistent with the view that retrieval practice enhances list segregation processes. Such processes may reduce interference between lists and thus reduce directed forgetting. PMID:26286882
Retrieval practice can eliminate list method directed forgetting.
Abel, Magdalena; Bäuml, Karl-Heinz T
2016-01-01
It has recently been shown that retrieval practice can reduce memories' susceptibility to interference, like retroactive and proactive interference. In this study, we therefore examined whether retrieval practice can also reduce list method directed forgetting, a form of intentional forgetting that presupposes interference. In each of two experiments, subjects successively studied two lists of items. After studying each single list, subjects restudied the list items to enhance learning, or they were asked to recall the items. Following restudy or retrieval practice of list 1 items, subjects were cued to either forget the list or remember it for an upcoming final test. Experiment 1 employed a free-recall and Experiment 1 a cued-recall procedure on the final memory test. In both experiments, directed forgetting was present in the restudy condition but was absent in the retrieval-practice condition, indicating that retrieval practice can reduce or even eliminate this form of forgetting. The results are consistent with the view that retrieval practice enhances list segregation processes. Such processes may reduce interference between lists and thus reduce directed forgetting.
Explicit Integration of Extremely Stiff Reaction Networks: Asymptotic Methods
Guidry, Mike W; Budiardja, R.; Feger, E.; Billings, J. J.; Hix, William Raphael; Messer, O.E.B.; Roche, K. J.; McMahon, E.; He, M.
2013-01-01
We show that, even for extremely stiff systems, explicit integration may compete in both accuracy and speed with implicit methods if algebraic methods are used to stabilize the numerical integration. The stabilizing algebra differs for systems well removed from equilibrium and those near equilibrium. This paper introduces a quantitative distinction between these two regimes and addresses the former case in depth, presenting explicit asymptotic methods appropriate when the system is extremely stiff but only weakly equilibrated. A second paper [1] examines quasi-steady-state methods as an alternative to asymptotic methods in systems well away from equilibrium and a third paper [2] extends these methods to equilibrium conditions in extremely stiff systems using partial equilibrium methods. All three papers present systematic evidence for timesteps competitive with implicit methods. Because explicit methods can execute a timestep faster than an implicit method, our results imply that algebraically stabilized explicit algorithms may offer a means to integration of larger networks than have been feasible previously in various disciplines.
Method and apparatus for high-efficiency direct contact condensation
Bharathan, Desikan; Parent, Yves; Hassani, A. Vahab
1999-01-01
A direct contact condenser having a downward vapor flow chamber and an upward vapor flow chamber, wherein each of the vapor flow chambers includes a plurality of cooling liquid supplying pipes and a vapor-liquid contact medium disposed thereunder to facilitate contact and direct heat exchange between the vapor and cooling liquid. The contact medium includes a plurality of sheets arranged to form vertical interleaved channels or passageways for the vapor and cooling liquid streams. The upward vapor flow chamber also includes a second set of cooling liquid supplying pipes disposed beneath the vapor-liquid contact medium which operate intermittently in response to a pressure differential within the upward vapor flow chamber. The condenser further includes separate wells for collecting condensate and cooling liquid from each of the vapor flow chambers. In alternate embodiments, the condenser includes a cross-current flow chamber and an upward flow chamber, a plurality of upward flow chambers, or a single upward flow chamber. The method of use of the direct contact condenser of this invention includes passing a vapor stream sequentially through the downward and upward vapor flow chambers, where the vapor is condensed as a result of heat exchange with the cooling liquid in the contact medium. The concentration of noncondensable gases in the resulting condensate-liquid mixtures can be minimized by controlling the partial pressure of the vapor, which depends in part upon the geometry of the vapor-liquid contact medium. In another aspect of this invention, the physical and chemical performance of a direct contact condenser can be predicted based on the vapor and coolant compositions, the condensation conditions. and the geometric properties of the contact medium.
Method and apparatus for high-efficiency direct contact condensation
Bharathan, D.; Parent, Y.; Hassani, A.V.
1999-07-20
A direct contact condenser having a downward vapor flow chamber and an upward vapor flow chamber, wherein each of the vapor flow chambers includes a plurality of cooling liquid supplying pipes and a vapor-liquid contact medium disposed thereunder to facilitate contact and direct heat exchange between the vapor and cooling liquid. The contact medium includes a plurality of sheets arranged to form vertical interleaved channels or passageways for the vapor and cooling liquid streams. The upward vapor flow chamber also includes a second set of cooling liquid supplying pipes disposed beneath the vapor-liquid contact medium which operate intermittently in response to a pressure differential within the upward vapor flow chamber. The condenser further includes separate wells for collecting condensate and cooling liquid from each of the vapor flow chambers. In alternate embodiments, the condenser includes a cross-current flow chamber and an upward flow chamber, a plurality of upward flow chambers, or a single upward flow chamber. The method of use of the direct contact condenser of this invention includes passing a vapor stream sequentially through the downward and upward vapor flow chambers, where the vapor is condensed as a result of heat exchange with the cooling liquid in the contact medium. The concentration of noncondensable gases in the resulting condensate-liquid mixtures can be minimized by controlling the partial pressure of the vapor, which depends in part upon the geometry of the vapor-liquid contact medium. In another aspect of this invention, the physical and chemical performance of a direct contact condenser can be predicted based on the vapor and coolant compositions, the condensation conditions, and the geometric properties of the contact medium. 39 figs.
Methods and future directions for paleoclimatology in the Maya Lowlands
NASA Astrophysics Data System (ADS)
Douglas, Peter M. J.; Brenner, Mark; Curtis, Jason H.
2016-03-01
A growing body of paleoclimate data indicates that periods of severe drought affected the Maya Lowlands of southeastern Mexico and northern Central America, especially during the Terminal Classic period (ca. 800-950 CE), raising the possibility that climate change contributed to the widespread collapse of many Maya polities at that time. A broad range of paleoclimate proxy methods have been applied in the Maya Lowlands and the data derived from these methods are sometimes challenging for archeologists and other non-specialists to interpret. This paper reviews the principal methods used for paleoclimate inference in the region and the rationale for climate proxy interpretation to help researchers working in the Maya Lowlands make sense of paleoclimate datasets. In particular, we focus on analyses of speleothems and lake sediment cores. These two paleoclimate archives have been most widely applied in the Maya Lowlands and have the greatest potential to provide insights into climate change impacts on the ancient Maya. We discuss the development of chronologies for these climate archives, the proxies for past climate change found within them, and how these proxy variables are interpreted. Finally, we present strategies for improving our understanding of proxy paleoclimate data from the Maya Lowlands, including multi-proxy analyses, assessment of spatial variability in past climate change, combined analysis of climate models and proxy data, and the integration of paleoclimatology and archeology.
A direct method for e-cigarette aerosol sample collection.
Olmedo, Pablo; Navas-Acien, Ana; Hess, Catherine; Jarmul, Stephanie; Rule, Ana
2016-08-01
E-cigarette use is increasing in populations around the world. Recent evidence has shown that the aerosol produced by e-cigarettes can contain a variety of toxicants. Published studies characterizing toxicants in e-cigarette aerosol have relied on filters, impingers or sorbent tubes, which are methods that require diluting or extracting the sample in a solution during collection. We have developed a collection system that directly condenses e-cigarette aerosol samples for chemical and toxicological analyses. The collection system consists of several cut pipette tips connected with short pieces of tubing. The pipette tip-based collection system can be connected to a peristaltic pump, a vacuum pump, or directly to an e-cigarette user for the e-cigarette aerosol to flow through the system. The pipette tip-based system condenses the aerosol produced by the e-cigarette and collects a liquid sample that is ready for analysis without the need of intermediate extraction solutions. We tested a total of 20 e-cigarettes from 5 different brands commercially available in Maryland. The pipette tip-based collection system condensed between 0.23 and 0.53mL of post-vaped e-liquid after 150 puffs. The proposed method is highly adaptable, can be used during field work and in experimental settings, and allows collecting aerosol samples from a wide variety of e-cigarette devices, yielding a condensate of the likely exact substance that is being delivered to the lungs.
A direct method for e-cigarette aerosol sample collection.
Olmedo, Pablo; Navas-Acien, Ana; Hess, Catherine; Jarmul, Stephanie; Rule, Ana
2016-08-01
E-cigarette use is increasing in populations around the world. Recent evidence has shown that the aerosol produced by e-cigarettes can contain a variety of toxicants. Published studies characterizing toxicants in e-cigarette aerosol have relied on filters, impingers or sorbent tubes, which are methods that require diluting or extracting the sample in a solution during collection. We have developed a collection system that directly condenses e-cigarette aerosol samples for chemical and toxicological analyses. The collection system consists of several cut pipette tips connected with short pieces of tubing. The pipette tip-based collection system can be connected to a peristaltic pump, a vacuum pump, or directly to an e-cigarette user for the e-cigarette aerosol to flow through the system. The pipette tip-based system condenses the aerosol produced by the e-cigarette and collects a liquid sample that is ready for analysis without the need of intermediate extraction solutions. We tested a total of 20 e-cigarettes from 5 different brands commercially available in Maryland. The pipette tip-based collection system condensed between 0.23 and 0.53mL of post-vaped e-liquid after 150 puffs. The proposed method is highly adaptable, can be used during field work and in experimental settings, and allows collecting aerosol samples from a wide variety of e-cigarette devices, yielding a condensate of the likely exact substance that is being delivered to the lungs. PMID:27200479
Integrative methods for analyzing big data in precision medicine.
Gligorijević, Vladimir; Malod-Dognin, Noël; Pržulj, Nataša
2016-03-01
We provide an overview of recent developments in big data analyses in the context of precision medicine and health informatics. With the advance in technologies capturing molecular and medical data, we entered the area of "Big Data" in biology and medicine. These data offer many opportunities to advance precision medicine. We outline key challenges in precision medicine and present recent advances in data integration-based methods to uncover personalized information from big data produced by various omics studies. We survey recent integrative methods for disease subtyping, biomarkers discovery, and drug repurposing, and list the tools that are available to domain scientists. Given the ever-growing nature of these big data, we highlight key issues that big data integration methods will face.
Statistical length measurement method by direct imaging of carbon nanotubes.
Bengio, E Amram; Tsentalovich, Dmitri E; Behabtu, Natnael; Kleinerman, Olga; Kesselman, Ellina; Schmidt, Judith; Talmon, Yeshayahu; Pasquali, Matteo
2014-05-14
The influence of carbon nanotube (CNT) length on their macroscopic properties requires an accurate methodology for CNT length measurement. So far, existing techniques are limited to short (less than a few micrometers) CNTs and sample preparation methods that bias the measured values. Here, we show that the average length of carbon nanotubes (CNTs) can be measured by cryogenic transmission electron microscopy (cryo-TEM) of CNTs in chlorosulfonic acid. The method consists of dissolving at low concentration CNTs in chlorosulfonic acid (a true solvent), imaging the individual CNTs by cryo-TEM, and processing and analyzing the images to determine CNT length. By measuring the total CNT contour length and number of CNT ends in each image, and by applying statistical analysis, we extend the method to cases where each CNT is long enough to span many cryo-TEM images, making the direct length measurement of an entire CNT impractical. Hence, this new technique can be used effectively to estimate samples in a wide range of CNT lengths, although we find that cryo-TEM imaging may bias the measurement towards longer CNTs, which are easier to detect. Our statistical method is also applied to AFM images of CNTs to show that, by using only a few AFM images, it yields estimates that are consistent with literature techniques, based on individually measuring a higher number of CNTs. PMID:24773046
Reaching a consensus in networks of high-order integral agents under switching directed topologies
NASA Astrophysics Data System (ADS)
Cheng, Long; Wang, Hanlei; Hou, Zeng-Guang; Tan, Min
2016-06-01
Consensus problem of high-order integral multi-agent systems under switching directed topology is considered in this study. Depending on whether the agent's full state is available or not, two distributed protocols are proposed to ensure that states of all agents can be convergent to a same stationary value. In the proposed protocols, the gain vector associated with the agent's (estimated) state and the gain vector associated with the relative (estimated) states between agents are designed in a sophisticated way. By this particular design, the high-order integral multi-agent system can be transformed into a first-order integral multi-agent system. Also, the convergence of the transformed first-order integral agent's state indicates the convergence of the original high-order integral agent's state, if and only if all roots of the polynomial, whose coefficients are the entries of the gain vector associated with the relative (estimated) states between agents, are in the open left-half complex plane. Therefore, many analysis techniques in the first-order integral multi-agent system can be directly borrowed to solve the problems in the high-order integral multi-agent system. Due to this property, it is proved that to reach a consensus, the switching directed topology of multi-agent system is only required to be 'uniformly jointly quasi-strongly connected', which seems the mildest connectivity condition in the literature. In addition, the consensus problem of discrete-time high-order integral multi-agent systems is studied. The corresponding consensus protocol and performance analysis are presented. Finally, three simulation examples are provided to show the effectiveness of the proposed approach.
Scenario driven data modelling: a method for integrating diverse sources of data and data streams
Brettin, Thomas S.; Cottingham, Robert W.; Griffith, Shelton D.; Quest, Daniel J.
2015-09-08
A system and method of integrating diverse sources of data and data streams is presented. The method can include selecting a scenario based on a topic, creating a multi-relational directed graph based on the scenario, identifying and converting resources in accordance with the scenario and updating the multi-directed graph based on the resources, identifying data feeds in accordance with the scenario and updating the multi-directed graph based on the data feeds, identifying analytical routines in accordance with the scenario and updating the multi-directed graph using the analytical routines and identifying data outputs in accordance with the scenario and defining queries to produce the data outputs from the multi-directed graph.
Heilmann, R.; Keil, R.; Gräfe, M.; Nolte, S.; Szameit, A.
2014-08-11
We present an innovative approach for ultra-precise phase manipulation in integrated photonic quantum circuits. To this end, we employ generalized directional couplers that utilize a detuning of the propagation constant in optical waveguides by the overlap of adjacent waveguide modes. We demonstrate our findings in experiments with classical as well as quantum light.
Mechanical System Reliability and Cost Integration Using a Sequential Linear Approximation Method
NASA Technical Reports Server (NTRS)
Kowal, Michael T.
1997-01-01
The development of new products is dependent on product designs that incorporate high levels of reliability along with a design that meets predetermined levels of system cost. Additional constraints on the product include explicit and implicit performance requirements. Existing reliability and cost prediction methods result in no direct linkage between variables affecting these two dominant product attributes. A methodology to integrate reliability and cost estimates using a sequential linear approximation method is proposed. The sequential linear approximation method utilizes probability of failure sensitivities determined from probabilistic reliability methods as well a manufacturing cost sensitivities. The application of the sequential linear approximation method to a mechanical system is demonstrated.
Accelerometer Method and Apparatus for Integral Display and Control Functions
NASA Technical Reports Server (NTRS)
Bozeman, Richard J., Jr. (Inventor)
1996-01-01
Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. Art accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.
Accelerometer Method and Apparatus for Integral Display and Control Functions
NASA Technical Reports Server (NTRS)
Bozeman, Richard J., Jr. (Inventor)
1998-01-01
Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto is discussed. An accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.
Direct Ceromers: assuring restorative integrity with selective application of two viscosities.
Liebenberg, W H
1997-01-01
The objectives of an ideal direct restoration include pulpal health, biocompatibility, occlusal stability, anatomical restitution, marginal perfection, and interproximal integrity. While tooth-colored composites have replaced amalgam as the restorative material of choice for many dental professionals, the utilization of composite materials of two different viscosities has proven effective in increasing strength and adaptation, and facilitating placement of anterior and posterior restorations. Several newly enhanced composite combinations have begun to allay reservations about directly placed tooth-colored restorations. This article classifies the ideal handling characteristics and benefits of a recently introduced, direct Ceromer system (Tetric Flow and Tetric Ceram, Ivoclar Vivadent, Amherst, NY.)
Trojan Horse method for direct and resonant reactions
NASA Astrophysics Data System (ADS)
Mukhamedzhanov, A. M.
The Trojan Horse method (THM) is a powerful indirect technique that provides information to determine astrophysical factors for binary rearrangement processes x + A to b + B at astrophysically relevant energies by measuring the cross section for the Trojan Horse (TH) reaction a + A to y + b + B in the quasifree kinematics. The theory of the THM both for direct and resonant binary subreactions is presented based on the few-body approach and Green's function formalism. The off-energy-shell effects and initial and final state interactions have been taken into account. To treat the resonance processes we developed the half-off-energy-shell R matrix approach. Examples are presented to demonstrate how THM works.
Multistep and Multistage Boundary Integral Methods for the Wave Equation
NASA Astrophysics Data System (ADS)
Banjai, Lehel
2009-09-01
We describe how time-discretized wave equation in a homogeneous medium can be solved by boundary integral methods. The time discretization can be a multistep, Runge-Kutta, or a more general multistep-multistage method. The resulting convolutional system of boundary integral equations falls in the family of convolution quadratures of Ch. Lubich. In this work our aim is to discuss a new technique for efficiently solving the discrete convolutional system and to present large scale 3D numerical experiments with a wide range of time-discretizations that have up to now not appeared in print. One of the conclusions is that Runge-Kutta methods are often the method of choice even at low accuracy; yet, in connection with hyperbolic problems BDF (backward difference formulas) have been predominant in the literature on convolution quadrature.
An Integrated Approach to Research Methods and Capstone
ERIC Educational Resources Information Center
Postic, Robert; McCandless, Ray; Stewart, Beth
2014-01-01
In 1991, the AACU issued a report on improving undergraduate education suggesting, in part, that a curriculum should be both comprehensive and cohesive. Since 2008, we have systematically integrated our research methods course with our capstone course in an attempt to accomplish the twin goals of comprehensiveness and cohesion. By taking this…
Integrating Methods and Materials: Developing Trainees' Reading Skills.
ERIC Educational Resources Information Center
Jarvis, Jennifer
1987-01-01
Explores issues arising from a research project which studied ways of meeting the reading needs of trainee primary school teachers (from Malawi and Tanzania) of English as a foreign language. Topics discussed include: the classroom teaching situation; teaching "quality"; and integration of materials and methods. (CB)
Processing of alnico permanent magnets by advanced directional solidification methods
Zou, Min; Johnson, Francis; Zhang, Wanming; Zhao, Qi; Rutkowski, Stephen F.; Zhou, Lin; Kramer, Matthew J.
2016-07-05
Advanced directional solidification methods have been used to produce large (>15 cm length) castings of Alnico permanent magnets with highly oriented columnar microstructures. In combination with subsequent thermomagnetic and draw thermal treatment, this method was used to enable the high coercivity, high-Titanium Alnico composition of 39% Co, 29.5% Fe, 14% Ni, 7.5% Ti, 7% Al, 3% Cu (wt%) to have an intrinsic coercivity (Hci) of 2.0 kOe, a remanence (Br) of 10.2 kG, and an energy product (BH)max of 10.9 MGOe. These properties compare favorably to typical properties for the commercial Alnico 9. Directional solidification of higher Ti compositions yieldedmore » anisotropic columnar grained microstructures if high heat extraction rates through the mold surface of at least 200 kW/m2 were attained. This was achieved through the use of a thin walled (5 mm thick) high thermal conductivity SiC shell mold extracted from a molten Sn bath at a withdrawal rate of at least 200 mm/h. However, higher Ti compositions did not result in further increases in magnet performance. Images of the microstructures collected by scanning electron microscopy (SEM) reveal a majority α phase with inclusions of secondary αγ phase. Transmission electron microscopy (TEM) reveals that the α phase has a spinodally decomposed microstructure of FeCo-rich needles in a NiAl-rich matrix. In the 7.5% Ti composition the diameter distribution of the FeCo needles was bimodal with the majority having diameters of approximately 50 nm with a small fraction having diameters of approximately 10 nm. The needles formed a mosaic pattern and were elongated along one <001> crystal direction (parallel to the field used during magnetic annealing). Cu precipitates were observed between the needles. Regions of abnormal spinodal morphology appeared to correlate with secondary phase precipitates. The presence of these abnormalities did not prevent the material from displaying superior magnetic properties in the 7.5% Ti
Processing of alnico permanent magnets by advanced directional solidification methods
NASA Astrophysics Data System (ADS)
Zou, Min; Johnson, Francis; Zhang, Wanming; Zhao, Qi; Rutkowski, Stephen F.; Zhou, Lin; Kramer, Matthew J.
2016-12-01
Advanced directional solidification methods have been used to produce large (>15 cm length) castings of Alnico permanent magnets with highly oriented columnar microstructures. In combination with subsequent thermomagnetic and draw thermal treatment, this method was used to enable the high coercivity, high-Titanium Alnico composition of 39% Co, 29.5% Fe, 14% Ni, 7.5% Ti, 7% Al, 3% Cu (wt%) to have an intrinsic coercivity (Hci) of 2.0 kOe, a remanence (Br) of 10.2 kG, and an energy product (BH)max of 10.9 MGOe. These properties compare favorably to typical properties for the commercial Alnico 9. Directional solidification of higher Ti compositions yielded anisotropic columnar grained microstructures if high heat extraction rates through the mold surface of at least 200 kW/m2 were attained. This was achieved through the use of a thin walled (5 mm thick) high thermal conductivity SiC shell mold extracted from a molten Sn bath at a withdrawal rate of at least 200 mm/h. However, higher Ti compositions did not result in further increases in magnet performance. Images of the microstructures collected by scanning electron microscopy (SEM) reveal a majority α phase with inclusions of secondary αγ phase. Transmission electron microscopy (TEM) reveals that the α phase has a spinodally decomposed microstructure of FeCo-rich needles in a NiAl-rich matrix. In the 7.5% Ti composition the diameter distribution of the FeCo needles was bimodal with the majority having diameters of approximately 50 nm with a small fraction having diameters of approximately 10 nm. The needles formed a mosaic pattern and were elongated along one <001> crystal direction (parallel to the field used during magnetic annealing). Cu precipitates were observed between the needles. Regions of abnormal spinodal morphology appeared to correlate with secondary phase precipitates. The presence of these abnormalities did not prevent the material from displaying superior magnetic properties in the 7.5% Ti
Spatial integration of optic flow information in direction of heading judgments
Issen, Laurel; Huxlin, Krystel R.; Knill, David
2015-01-01
While we know that humans are extremely sensitive to optic flow information about direction of heading, we do not know how they integrate information across the visual field. We adapted the standard cue perturbation paradigm to investigate how young adult observers integrate optic flow information from different regions of the visual field to judge direction of heading. First, subjects judged direction of heading when viewing a three-dimensional field of random dots simulating linear translation through the world. We independently perturbed the flow in one visual field quadrant to indicate a different direction of heading relative to the other three quadrants. We then used subjects' judgments of direction of heading to estimate the relative influence of flow information in each quadrant on perception. Human subjects behaved similarly to the ideal observer in terms of integrating motion information across the visual field with one exception: Subjects overweighted information in the upper half of the visual field. The upper-field bias was robust under several different stimulus conditions, suggesting that it may represent a physiological adaptation to the uneven distribution of task-relevant motion information in our visual world. PMID:26024461
Singularity Preserving Numerical Methods for Boundary Integral Equations
NASA Technical Reports Server (NTRS)
Kaneko, Hideaki (Principal Investigator)
1996-01-01
In the past twelve months (May 8, 1995 - May 8, 1996), under the cooperative agreement with Division of Multidisciplinary Optimization at NASA Langley, we have accomplished the following five projects: a note on the finite element method with singular basis functions; numerical quadrature for weakly singular integrals; superconvergence of degenerate kernel method; superconvergence of the iterated collocation method for Hammersteion equations; and singularity preserving Galerkin method for Hammerstein equations with logarithmic kernel. This final report consists of five papers describing these projects. Each project is preceeded by a brief abstract.
Adaptive Transmission Control Method for Communication-Broadcasting Integrated Services
NASA Astrophysics Data System (ADS)
Koto, Hideyuki; Furuya, Hiroki; Nakamura, Hajime
This paper proposes an adaptive transmission control method for massive and intensive telecommunication traffic generated by communication-broadcasting integrated services. The proposed method adaptively controls data transmissions from viewers depending on the congestion states, so that severe congestion can be effectively avoided. Furthermore, it utilizes the broadcasting channel which is not only scalable, but also reliable for controlling the responses from vast numbers of viewers. The performance of the proposed method is evaluated through experiments on a test bed where approximately one million viewers are emulated. The obtained results quantitatively demonstrate the performance of the proposed method and its effectiveness under massive and intensive traffic conditions.
Nodal integral method for transient heat conduction in a cylinder
Esser, P.D. )
1993-01-01
The accuracy and efficiency of nodal solution methods are well established for neutron diffusion in a variety of geometries, as well as for heat transfer and fluid flow in rectangular coordinates. This paper describes the development of a nodal integral method to solve the transient heat conduction equation in cylindrical geometry. Results for a test problem with an analytical solution indicate that the nodal solution provides higher accuracy than a conventional implicit finite difference scheme, while maintaining similar stability characteristics.
Mechanical integrity test methods for Class 2 injection wells
Smith, K.P.
1991-03-01
Mechanical integrity testing of injection wells to ensure that they do not threaten an underground source of drinking water (USDW) is a key component of the Underground Injection Control (UIC) program of the Safe Drinking Water Act of 1974. Approximately 55% of all active injection wells are classified as Class II wells. These wells are used by the oil and gas industry primarily to dispose of waste fluids or to enhance production of hydrocarbons. Mechanical integrity is defined as the absence of significant leaks in the casing, tubing, or packers (internal integrity); and the absence of significant fluid movement into a USDW through cement channels behind the casing (external integrity). A wide variety of mechanical integrity test (MIT) methods have been developed to meet federal and primacy state program requirements. The internal mechanical integrity of standard injection wells can be evaluated by radioactive tracer surveys, standard annular pressure tests, annulus pressure monitoring, and continuous injection pressure versus injection rate monitoring. These tests are listed in order of decreasing reliability and increasing detection limits. 28 refs., 17 figs., 6 tabs.
Adaptive integral method with fast Gaussian gridding for solving combined field integral equations
NASA Astrophysics Data System (ADS)
Bakır, O.; Baǧ; Cı, H.; Michielssen, E.
Fast Gaussian gridding (FGG), a recently proposed nonuniform fast Fourier transform algorithm, is used to reduce the memory requirements of the adaptive integral method (AIM) for accelerating the method of moments-based solution of combined field integral equations pertinent to the analysis of scattering from three-dimensional perfect electrically conducting surfaces. Numerical results that demonstrate the efficiency and accuracy of the AIM-FGG hybrid in comparison to an AIM-accelerated solver, which uses moment matching to project surface sources onto an auxiliary grid, are presented.
Monte Carlo methods for multidimensional integration for European option pricing
NASA Astrophysics Data System (ADS)
Todorov, V.; Dimov, I. T.
2016-10-01
In this paper, we illustrate examples of highly accurate Monte Carlo and quasi-Monte Carlo methods for multiple integrals related to the evaluation of European style options. The idea is that the value of the option is formulated in terms of the expectation of some random variable; then the average of independent samples of this random variable is used to estimate the value of the option. First we obtain an integral representation for the value of the option using the risk neutral valuation formula. Then with an appropriations change of the constants we obtain a multidimensional integral over the unit hypercube of the corresponding dimensionality. Then we compare a specific type of lattice rules over one of the best low discrepancy sequence of Sobol for numerical integration. Quasi-Monte Carlo methods are compared with Adaptive and Crude Monte Carlo techniques for solving the problem. The four approaches are completely different thus it is a question of interest to know which one of them outperforms the other for evaluation multidimensional integrals in finance. Some of the advantages and disadvantages of the developed algorithms are discussed.
NASA Astrophysics Data System (ADS)
Ganguly, Pranabendu; Biswas, Juran Chandra; Lahiri, Samir Kumar
Integrated optic directional couplers consisting of curved waveguides are simulated analytically by solving the Riccati equation. The coupling coefficient between the curved waveguides with a parabolically varying gap and the condition of total power transfer between the waveguides are derived. In order to compute the overall coupling coefficient and hence the power distribution along the waveguides for Ti:LiNbO3 curved waveguide directional couplers, the coupling coefficient for straight waveguide couplers is computed for different gaps using the effective-index-based matrix method (EIMM). Finally, the power distribution in the curved waveguides along the length is computed. The method is mostly analytical except the effective-index method and is computationally simple.
NASA Technical Reports Server (NTRS)
Vess, Melissa F.; Starin, Scott R.
2007-01-01
During design of the SDO Science and Inertial mode PID controllers, the decision was made to disable the integral torque whenever system stability was in question. Three different schemes were developed to determine when to disable or enable the integral torque, and a trade study was performed to determine which scheme to implement. The trade study compared complexity of the control logic, risk of not reenabling the integral gain in time to reject steady-state error, and the amount of integral torque space used. The first scheme calculated a simplified Routh criterion to determine when to disable the integral torque. The second scheme calculates the PD part of the torque and looked to see if that torque would cause actuator saturation. If so, only the PD torque is used. If not, the integral torque is added. Finally, the third scheme compares the attitude and rate errors to limits and disables the integral torque if either of the errors is greater than the limit. Based on the trade study results, the third scheme was selected. Once it was decided when to disable the integral torque, analysis was performed to determine how to disable the integral torque and whether or not to reset the integrator once the integral torque was reenabled. Three ways to disable the integral torque were investigated: zero the input into the integrator, which causes the integral part of the PID control torque to be held constant; zero the integral torque directly but allow the integrator to continue integrating; or zero the integral torque directly and reset the integrator on integral torque reactivation. The analysis looked at complexity of the control logic, slew time plus settling time between each calibration maneuver step, and ability to reject steady-state error. Based on the results of the analysis, the decision was made to zero the input into the integrator without resetting it. Throughout the analysis, a high fidelity simulation was used to test the various implementation methods.
General method for sequence-independent site-directed chimeragenesis.
Hiraga, Kaori; Arnold, Frances H
2003-07-01
We have developed a simple and general method that allows for the facile recombination of distantly related (or unrelated) proteins at multiple discrete sites. To evaluate the sequence-independent site-directed chimeragenesis (SISDC) method, we have recombined beta-lactamases TEM-1 and PSE-4 at seven sites, examined the quality of the chimeric genes created, and screened the library of 2(8) (256) chimeras for functional enzymes. Probe hybridization and sequencing analyses revealed that SISDC generated a random library with little sequence bias and in which all targeted fragments were recombined in the desired order. Sequencing the genes from clones having functional lactamases identified 14 unique chimeras. These chimeras are characterized by a lower level of disruption, as calculated by the SCHEMA algorithm, than the library as a whole. These results illustrate the use of SISDC in creating designed chimeric protein libraries and further illustrate the ability of SCHEMA to identify chimeras whose folded structures are likely not to be disrupted by recombination. PMID:12823968
On resolution of the method of directional magnetotelluric soundings
NASA Astrophysics Data System (ADS)
Savin, Mihail
2015-12-01
The problem is to examine the resolution of directional magnetotelluric soundings (DMTS). Abrupt changes of impedances Z^e,h of electrical and magnetic types in critical region of parameters R 0, Jωμσ where R=Re[(K_x)2+(K_y)2], J=Im[(K_x)2+(K_y)2] are shown to result in significantly higher resolution of the method as compared with the traditional interpretation using Tikhonov-Cagniard impedance Z^0. The stability of solution of DMTS method inverse problem is considered subject to field measurement errors limited the resolution. The minimum of the limits is determined for the conductivity Δσ/σ small variations. For studying DMTS resolution as applied to MT monitoring of earthquake site the mathematical experiment for three-layer geoelectric model was carried out. When changing the earthquake site conductivity of Δσ ∼ ±10 variations of reflection coefficient of electric mode ΔQe are in the range of 20% that is significantly more than the field measurement error. The possibility for prediction modeling in the context of obtained results is discussed.
Xiong, Ying-Zi; Xie, Xin-Yu; Yu, Cong
2016-02-01
Recent studies reported significantly less location specificity in motion direction learning than in previous classical studies. The latter performed training with the method of constant stimuli containing a single level of direction difference. In contrast the former used staircase methods that varied the direction difference trial by trial. We suspect that extensive practice with a single direction difference could allow an observer to use some subtle local cues for direction discrimination. Such local cues may be unavailable at a new stimulus location, leading to higher location specificity. To test this hypothesis, we jittered slightly the directions of a stimulus pair by the same amount while keeping the direction difference constant, so as to disturb the potential local cues. We observed significantly more transfer of learning to untrained locations. The local cue effects may also explain the recent controversies regarding the finding that foveal motion direction learning becomes significantly more transferrable to a new direction with TPE (training-plus-exposure) training. One specific study by Zili Liu and collaborators that challenges this finding also used a single-level direction difference for training. We first replicated their results. But we found that if the directions of the stimulus pair were again jittered while the direction difference was kept constant, motion direction learning transferred significantly more to an orthogonal direction with TPE training. Our results thus demonstrate the importance of using appropriate psychophysical methods in training to reduce local-cue related specificity in perceptual learning.
Liu, Peigui; Elshall, Ahmed S.; Ye, Ming; Beerli, Peter; Zeng, Xiankui; Lu, Dan; Tao, Yuezan
2016-02-05
Evaluating marginal likelihood is the most critical and computationally expensive task, when conducting Bayesian model averaging to quantify parametric and model uncertainties. The evaluation is commonly done by using Laplace approximations to evaluate semianalytical expressions of the marginal likelihood or by using Monte Carlo (MC) methods to evaluate arithmetic or harmonic mean of a joint likelihood function. This study introduces a new MC method, i.e., thermodynamic integration, which has not been attempted in environmental modeling. Instead of using samples only from prior parameter space (as in arithmetic mean evaluation) or posterior parameter space (as in harmonic mean evaluation), the thermodynamicmore » integration method uses samples generated gradually from the prior to posterior parameter space. This is done through a path sampling that conducts Markov chain Monte Carlo simulation with different power coefficient values applied to the joint likelihood function. The thermodynamic integration method is evaluated using three analytical functions by comparing the method with two variants of the Laplace approximation method and three MC methods, including the nested sampling method that is recently introduced into environmental modeling. The thermodynamic integration method outperforms the other methods in terms of their accuracy, convergence, and consistency. The thermodynamic integration method is also applied to a synthetic case of groundwater modeling with four alternative models. The application shows that model probabilities obtained using the thermodynamic integration method improves predictive performance of Bayesian model averaging. As a result, the thermodynamic integration method is mathematically rigorous, and its MC implementation is computationally general for a wide range of environmental problems.« less
Mixed time integration methods for transient thermal analysis of structures
NASA Technical Reports Server (NTRS)
Liu, W. K.
1983-01-01
The computational methods used to predict and optimize the thermal-structural behavior of aerospace vehicle structures are reviewed. In general, two classes of algorithms, implicit and explicit, are used in transient thermal analysis of structures. Each of these two methods has its own merits. Due to the different time scales of the mechanical and thermal responses, the selection of a time integration method can be a difficult yet critical factor in the efficient solution of such problems. Therefore mixed time integration methods for transient thermal analysis of structures are being developed. The computer implementation aspects and numerical evaluation of these mixed time implicit-explicit algorithms in thermal analysis of structures are presented. A computationally-useful method of estimating the critical time step for linear quadrilateral element is also given. Numerical tests confirm the stability criterion and accuracy characteristics of the methods. The superiority of these mixed time methods to the fully implicit method or the fully explicit method is also demonstrated.
rDNA-directed integration by an HIV-1 integrase--I-PpoI fusion protein.
Schenkwein, Diana; Turkki, Vesa; Ahlroth, Mervi K; Timonen, Oskari; Airenne, Kari J; Ylä-Herttuala, Seppo
2013-03-01
Integrating viral vectors are efficient gene transfer tools, but their integration patterns have been associated with genotoxicity and oncogenicity. The recent development of highly specific designer nucleases has enabled target DNA modification and site-specific gene insertion at desired genomic loci. However, a lack of consensus exists regarding a perfect genomic safe harbour (GSH) that would allow transgenes to be stably and reliably expressed without adversely affecting endogenous gene structure and function. Ribosomal DNA (rDNA) has many advantages as a GSH, but efficient means to target integration to this locus are currently lacking. We tested whether lentivirus vector integration can be directed to rDNA by using fusion proteins consisting of the Human Immunodeficiency Virus 1 (HIV-1) integrase (IN) and the homing endonuclease I-PpoI, which has natural cleavage sites in the rDNA. A point mutation (N119A) was introduced into I-PpoI to abolish unwanted DNA cleavage by the endonuclease. The vector-incorporated IN-I-PpoIN119A fusion protein targeted integration into rDNA significantly more than unmodified lentivirus vectors, with an efficiency of 2.7%. Our findings show that IN-fusion proteins can be used to modify the integration pattern of lentivirus vectors, and to package site-specific DNA-recognizing proteins into vectors to obtain safer transgene integration.
Integrated catalytic process to directly convert furfural to levulinate ester with high selectivity.
Chen, Bingfeng; Li, Fengbo; Huang, Zhijun; Lu, Tao; Yuan, Yin; Yuan, Guoqing
2014-01-01
Levulinic acid is an important platform molecule from biomass-based renewable resources. A sustainable manufacturing process for this chemical and its derivatives is the enabling factor to harness the renewable resource. An integrated catalytic process to directly convert furfural to levulinate ester was developed based on a bifunctional catalyst of Pt nanoparticles supported on a ZrNb binary phosphate solid acid. The hydrogenation of furfural and the following alcoholysis of furfuryl alcohol were performed over this catalyst in a one-pot conversion model. Mesoporous ZrNb binary phosphate was synthesized by a sol-gel method and had a high surface area of 170.1 m(2) g(-1) and a large average pore size of around 8.0 nm. Pt nanoparticles remained in a monodisperse state on the support, and the reaction over Pt/ZrNbPO4 (Pt loading: 2.0 wt%; Zr/Nb, 1:1) gave a very high selectivity to levulinate derivatives (91% in total). The sustainability of this conversion was greatly improved by the process intensification based on the new catalyst, mild reaction conditions, cost abatement in separation and purification, and utilization of green reagents and solvents.
Integrated catalytic process to directly convert furfural to levulinate ester with high selectivity.
Chen, Bingfeng; Li, Fengbo; Huang, Zhijun; Lu, Tao; Yuan, Yin; Yuan, Guoqing
2014-01-01
Levulinic acid is an important platform molecule from biomass-based renewable resources. A sustainable manufacturing process for this chemical and its derivatives is the enabling factor to harness the renewable resource. An integrated catalytic process to directly convert furfural to levulinate ester was developed based on a bifunctional catalyst of Pt nanoparticles supported on a ZrNb binary phosphate solid acid. The hydrogenation of furfural and the following alcoholysis of furfuryl alcohol were performed over this catalyst in a one-pot conversion model. Mesoporous ZrNb binary phosphate was synthesized by a sol-gel method and had a high surface area of 170.1 m(2) g(-1) and a large average pore size of around 8.0 nm. Pt nanoparticles remained in a monodisperse state on the support, and the reaction over Pt/ZrNbPO4 (Pt loading: 2.0 wt%; Zr/Nb, 1:1) gave a very high selectivity to levulinate derivatives (91% in total). The sustainability of this conversion was greatly improved by the process intensification based on the new catalyst, mild reaction conditions, cost abatement in separation and purification, and utilization of green reagents and solvents. PMID:24194497
Integration of offshore wind farms through high voltage direct current networks
NASA Astrophysics Data System (ADS)
Livermore, Luke
The integration of offshore wind farms through Multi Terminal DC (MTDC) networks into the GB network was investigated. The ability of Voltage Source Converter (VSC) High Voltage Direct Current (HVDC) to damp Subsynchronous Resonance (SSR) and ride through onshore AC faults was studied. Due to increased levels of wind generation in Scotland, substantial onshore and offshore reinforcements to the GB transmission network are proposed. Possible inland reinforcements include the use of series compensation through fixed capacitors. This potentially can lead to SSR. Offshore reinforcements are proposed by two HVDC links. In addition to its primary functions of bulk power transmission, a HVDC link can be used to provide damping against SSR, and this function has been modelled. Simulation studies have been carried out in PSCAD. In addition, a real-time hardware-in-the-loop HVDC test rig has been used to implement and validate the proposed damping scheme on an experimental platform. When faults occur within AC onshore networks, offshore MTDC networks are vulnerable to DC overvoltages, potentially damaging the DC plant and cables. Power reduction and power dissipation control systems were investigated to ride through onshore AC faults. These methods do not require dedicated fast communication systems. Simulations and laboratory experiments are carried out to evaluate the control systems, with the results from the two platforms compared..
Ghorbanian, Setareh; Qasaimeh, Mohammad A; Akbari, Mohsen; Tamayol, Ali; Juncker, David
2014-06-01
Cell distribution and nutrient supply in 3D cell-laden hydrogel scaffolds are critical and should mimic the in vivo cellular environment, but been difficult to control with conventional fabrication methods. Here, we present a microfluidic direct writer (MFDW) to construct 3D cell-laden hydrogel structures with openings permitting media exchange. The MFDW comprises a monolithic microfluidic head, which delivers coaxial streams of cell-laden sodium alginate and calcium chloride solutions to form hydrogel fibers. Fiber diameter is controlled by adjusting the ratio of the volumetric flow rates. The MFDW head is mounted on a motorized stage, which is automatically controlled and moves at a speed synchronized with the speed of fiber fabrication. Head geometry, flow rates, and viscosity of the writing solutions were optimized to prevent the occurrence of curling and bulging. For continuous use, a highly reliable process is needed, which was accomplished with the integration of a declogging conduit supplying a solvent to dissolve the clogging gel. The MFDW was used for layer-by-layer fabrication of simple 3D structures with encapsulated cells. Assembly of 3D structures with distinct fibers is demonstrated by alternatively delivering two different alginate gel solutions. The MFDW head can be built rapidly and easily, and will allow 3D constructs for tissue engineering to be fabricated with multiple hydrogels and cell types.
Criteria for quantitative and qualitative data integration: mixed-methods research methodology.
Lee, Seonah; Smith, Carrol A M
2012-05-01
Many studies have emphasized the need and importance of a mixed-methods approach for evaluation of clinical information systems. However, those studies had no criteria to guide integration of multiple data sets. Integrating different data sets serves to actualize the paradigm that a mixed-methods approach argues; thus, we require criteria that provide the right direction to integrate quantitative and qualitative data. The first author used a set of criteria organized from a literature search for integration of multiple data sets from mixed-methods research. The purpose of this article was to reorganize the identified criteria. Through critical appraisal of the reasons for designing mixed-methods research, three criteria resulted: validation, complementarity, and discrepancy. In applying the criteria to empirical data of a previous mixed methods study, integration of quantitative and qualitative data was achieved in a systematic manner. It helped us obtain a better organized understanding of the results. The criteria of this article offer the potential to produce insightful analyses of mixed-methods evaluations of health information systems.
Method for analyzing radiation sensitivity of integrated circuits
NASA Technical Reports Server (NTRS)
Gauthier, M. K.; Stanley, A. G. (Inventor)
1979-01-01
A method for analyzing the radiation sensitivity of an integrated circuit is described to determine the components. The application of a narrow radiation beam to portions of the circuit is considered. The circuit is operated under normal bias conditions during the application of radiation in a dosage that is likely to cause malfunction of at least some transistors, while the circuit is monitored for failure of the irradiated transistor. When a radiation sensitive transistor is found, then the radiation beam is further narrowed and, using a fresh integrated circuit, a very narrow beam is applied to different parts of the transistor, such as its junctions, to locate the points of greatest sensitivity.
Principles and methods of integrative genomic analyses in cancer.
Kristensen, Vessela N; Lingjærde, Ole Christian; Russnes, Hege G; Vollan, Hans Kristian M; Frigessi, Arnoldo; Børresen-Dale, Anne-Lise
2014-05-01
Combined analyses of molecular data, such as DNA copy-number alteration, mRNA and protein expression, point to biological functions and molecular pathways being deregulated in multiple cancers. Genomic, metabolomic and clinical data from various solid cancers and model systems are emerging and can be used to identify novel patient subgroups for tailored therapy and monitoring. The integrative genomics methodologies that are used to interpret these data require expertise in different disciplines, such as biology, medicine, mathematics, statistics and bioinformatics, and they can seem daunting. The objectives, methods and computational tools of integrative genomics that are available to date are reviewed here, as is their implementation in cancer research.
Method to integrate full particle orbit in toroidal plasmas
NASA Astrophysics Data System (ADS)
Wei, X. S.; Xiao, Y.; Kuley, A.; Lin, Z.
2015-09-01
It is important to integrate full particle orbit accurately when studying charged particle dynamics in electromagnetic waves with frequency higher than cyclotron frequency. We have derived a form of the Boris scheme using magnetic coordinates, which can be used effectively to integrate the cyclotron orbit in toroidal geometry over a long period of time. The new method has been verified by a full particle orbit simulation in toroidal geometry without high frequency waves. The full particle orbit calculation recovers guiding center banana orbit. This method has better numeric properties than the conventional Runge-Kutta method for conserving particle energy and magnetic moment. The toroidal precession frequency is found to match that from guiding center simulation. Many other important phenomena in the presence of an electric field, such as E × B drift, Ware pinch effect and neoclassical polarization drift are also verified by the full orbit simulation.
The integration of sequential aiming movements: Switching hand and direction at the first target.
Lawrence, G P; Khan, Michael A; Mottram, Thomas M; Adam, Jos J; Buckolz, Eric
2016-02-01
Movement times to a single target are typically shorter compared to when movement to a second target is required. This one target movement time advantage has been shown to emerge when participants use a single hand throughout the target sequence and when there is a switch between hands at the first target. Our goal was to investigate the lacuna in the movement integration literature surrounding the interactive effects between switching hands and changing movement direction at the first target. Participants performed rapid hand movements in five conditions; movements to a single target; two target movements with a single hand in which the second target required an extension or reversal in direction; and movements to two targets where the hands were switched at the first target and the second target required an extension or reversal in direction. The significance of including these latter two (multiple hand-multiple direction) movements meant that for the first time research could differentiate between peripheral and central processes within movement integration strategies. Reaction times were significantly shorter in the single task compared to the two target tasks. More importantly, movement times to the first target were significantly shorter in the single target task compared to all two target tasks (reflecting the so-called one target advantage), except when the second movement was a reversal movement with the same hand. These findings demonstrate for the first time the contrasting effects of movement integration at central and peripheral levels.
Modern microbiological methods for foods: colony count and direct count methods. A review.
García-Armesto, M R; Prieto, M; García-López, M L; Otero, A; Moreno, B
1993-04-01
Over the last years methods for enumeration of microorganisms in foods are changing rapidly. Techniques based on totally new concepts as well as instruments and miniaturized systems that allow the automation and simplification of existing microbiological procedures have been developed. These rapid methodologies should satisfy the increasing requirements for effective quality assurance of foods. In the present paper we review some of the more interesting methods based on colony count or direct bacterial count.
Numerical analysis of Weyl's method for integrating boundary layer equations
NASA Technical Reports Server (NTRS)
Najfeld, I.
1982-01-01
A fast method for accurate numerical integration of Blasius equation is proposed. It is based on the limit interchange in Weyl's fixed point method formulated as an iterated limit process. Each inner limit represents convergence to a discrete solution. It is shown that the error in a discrete solution admits asymptotic expansion in even powers of step size. An extrapolation process is set up to operate on a sequence of discrete solutions to reach the outer limit. Finally, this method is extended to related boundary layer equations.
[An integrated segmentation method for 3D ultrasound carotid artery].
Yang, Xin; Wu, Huihui; Liu, Yang; Xu, Hongwei; Liang, Huageng; Cai, Wenjuan; Fang, Mengjie; Wang, Yujie
2013-07-01
An integrated segmentation method for 3D ultrasound carotid artery was proposed. 3D ultrasound image was sliced into transverse, coronal and sagittal 2D images on the carotid bifurcation point. Then, the three images were processed respectively, and the carotid artery contours and thickness were obtained finally. This paper tries to overcome the disadvantages of current computer aided diagnosis method, such as high computational complexity, easily introduced subjective errors et al. The proposed method could get the carotid artery overall information rapidly, accurately and completely. It could be transplanted into clinical usage for atherosclerosis diagnosis and prevention. PMID:24195385
NASA Technical Reports Server (NTRS)
Atluri, Satya N.; Shen, Shengping
2002-01-01
In this paper, a very simple method is used to derive the weakly singular traction boundary integral equation based on the integral relationships for displacement gradients. The concept of the MLPG method is employed to solve the integral equations, especially those arising in solid mechanics. A moving Least Squares (MLS) interpolation is selected to approximate the trial functions in this paper. Five boundary integral Solution methods are introduced: direct solution method; displacement boundary-value problem; traction boundary-value problem; mixed boundary-value problem; and boundary variational principle. Based on the local weak form of the BIE, four different nodal-based local test functions are selected, leading to four different MLPG methods for each BIE solution method. These methods combine the advantages of the MLPG method and the boundary element method.
Directly laser-written integrated photonics devices including diffractive optical elements
NASA Astrophysics Data System (ADS)
Choi, Jiyeon; Ramme, Mark; Richardson, Martin
2016-08-01
Femtosecond laser-written integrated devices involving Fresnel Zone Plates (FZPs) and waveguide arrays are demonstrated as built-in optical couplers. These structures were fabricated in borosilicate glass using a direct laser writing technique. The optical properties of these integrated photonic structures were investigated using CW lasers and high-resolution CCDs. For a single FZP coupled to a single waveguide, the overall coupling efficiency was 9%. A multiplexed optical coupler composed of three FZP layers was demonstrated to couple three waveguides simultaneously in a waveguide array. Structures of this type can be used as platforms for multichannel waveguide coupling elements or as microfluidic sensors that require higher light collecting efficiency.
NASA Astrophysics Data System (ADS)
Hu, Yanxia; Yang, Xiaozhong
2006-08-01
A method for obtaining first integrals and integrating factors of n-th order autonomous systems is proposed. The search for first integrals and integrating factors can be reduced to the search for a class of invariant manifolds of the systems. Finally, the proposed method is applied to Euler-Poisson equations (gyroscope system), and the fourth first integral of the system in general Kovalevskaya case can be obtained.
An upwind nodal integral method for incompressible fluid flow
Esser, P.D. ); Witt, R.J. )
1993-05-01
An upwind nodal solution method is developed for the steady, two-dimensional flow of an incompressible fluid. The formulation is based on the nodal integral method, which uses transverse integrations, analytical solutions of the one-dimensional averaged equations, and node-averaged uniqueness constraints to derive the discretized nodal equations. The derivation introduces an exponential upwind bias by retaining the streamwise convection term in the homogeneous part of the transverse-integrated convection-diffusion equation. The method is adapted to the stream function-vorticity form of the Navier-Stokes equations, which are solved over a nonstaggered nodal mesh. A special nodal scheme is used for the Poisson stream function equation to properly account for the exponentially varying vorticity source. Rigorous expressions for the velocity components and the no-slip vorticity boundary condition are derived from the stream function formulation. The method is validated with several benchmark problems. An idealized purely convective flow of a scalar step function indicates that the nodal approximation errors are primarily dispersive, not dissipative, in nature. Results for idealized and actual recirculating driven-cavity flows reveal a significant reduction in false diffusion compared with conventional finite difference techniques.
Integrative clustering methods for high-dimensional molecular data
Chalise, Prabhakar; Koestler, Devin C.; Bimali, Milan; Yu, Qing; Fridley, Brooke L.
2014-01-01
High-throughput ‘omic’ data, such as gene expression, DNA methylation, DNA copy number, has played an instrumental role in furthering our understanding of the molecular basis in states of human health and disease. As cells with similar morphological characteristics can exhibit entirely different molecular profiles and because of the potential that these discrepancies might further our understanding of patient-level variability in clinical outcomes, there is significant interest in the use of high-throughput ‘omic’ data for the identification of novel molecular subtypes of a disease. While numerous clustering methods have been proposed for identifying of molecular subtypes, most were developed for single “omic’ data types and may not be appropriate when more than one ‘omic’ data type are collected on study subjects. Given that complex diseases, such as cancer, arise as a result of genomic, epigenomic, transcriptomic, and proteomic alterations, integrative clustering methods for the simultaneous clustering of multiple ‘omic’ data types have great potential to aid in molecular subtype discovery. Traditionally, ad hoc manual data integration has been performed using the results obtained from the clustering of individual ‘omic’ data types on the same set of patient samples. However, such methods often result in inconsistent assignment of subjects to the molecular cancer subtypes. Recently, several methods have been proposed in the literature that offers a rigorous framework for the simultaneous integration of multiple ‘omic’ data types in a single comprehensive analysis. In this paper, we present a systematic review of existing integrative clustering methods. PMID:25243110
Calibration of CNC milling machine by direct method
NASA Astrophysics Data System (ADS)
Khan, Abdul Wahid; Chen, Wuyi
2008-12-01
Calibration refers to the system of quantity value determination of instruments, equipments and test devices according to industrial requirement, based on metrological characteristics. In present research critical parameter which affects the accuracy and product quality of a CNC milling machine, was investigated and quantified by using direct method. These parameters consist of position dependent or position independent parameters, like linear displacement errors, angular errors of linear axes, straightness error of linear axes and squareness error between the axes. Repeatability, lead screw and resolution error of the CNC milling machine were also quantified to provide additional information to the user, because in absence of this additional information a misconception persists causing a major contributor to the inaccuracy and quality of the product. Parameters were measured and quantified by using a laser interferometer and artifacts as working standards under controlled environmental conditions on a manufacturing CNC milling machine. Polynomial regression analyses were carried out for finding the coefficients to predict the errors at each and every desired position which is quite useful for compensation and enhancing the accuracy of a machine system. Machine accuracy detailed chart was also made to assess and assure the accuracy, capability or for accuracy monitoring of the CNC milling machine
Cognitive load hypothesis of item-method directed forgetting.
Lee, Yuh-Shiow
2012-01-01
This study examined the effect of the processing demands of to-be-remembered (TBR) words on item-method directed forgetting. Experiment 1 found that a standard memory group remembered fewer to-be-forgotten (TBF) words than a naming group, in which participants simply named the TBR words during the study phase, even though both groups were equally instructed to forget the TBF words. Experiment 2 manipulated the number of TBR words in the study list, keeping the number of TBF words constant, and found that TBF word forgetting was more difficult in the few TBR words condition than the more TBR words condition. The same pattern was found in the result of Experiment 3 when a cued recall test, instead of a free recall test, was used. In all the experiments, participants were asked to recall the TBF words before the TBR words. These findings are consistent with the cognitive load hypothesis that it is easier to forget when there are fewer cognitive resources available during encoding. PMID:22372566
Method for directly recovering fluorine from gas streams
Orlett, Michael J.; Saraceno, Anthony J.
1981-01-01
This invention is a process for the direct recovery of gaseous fluorine from waste-gas streams or the like. The process comprises passing the gas stream through a bed of anhydrous K.sub.3 NiF.sub.6 pellets to fluorinate the same to K.sub.3 NiF.sub.7 and subsequently desorbing the fluorine by heating the K.sub.3 NiF.sub.7 pellets to a temperature re-converting them to K.sub.3 NiF.sub.6. The efficiency of the fluorine-absorption step is maximized by operating in a selected and conveniently low temperature. The desorbed fluorine is highly pure and is at a pressure of several atmospheres. Preferably, the K.sub.3 NiF.sub.6 pellets are prepared by a method including the steps of forming agglomerates of hydrated K.sub.3 NiF.sub.5, sintering the agglomerates to form K.sub.3 NiF.sub.5 pellets of enhanced reactivity with respect to fluorine, and fluorinating the sintered pellets to K.sub.3 NiF.sub.6.
Cluster growth processes by direct simulation monte carlo method
NASA Astrophysics Data System (ADS)
Mizuseki, H.; Jin, Y.; Kawazoe, Y.; Wille, L. T.
Thin films obtained by cluster deposition have attracted strong attention both as a new manufacturing technique to realize high-density magnetic recording media and to create systems with unique magnetic properties. Because the film's features are influenced by the cluster properties during the flight path, the relevant physical scale to be studied is as large as centimeters. In this paper, a new model of cluster growth processes based on a combination of the Direct Simulation Monte Carlo (DSMC) method and the cluster growth model is introduced to examine the effects of experimental conditions on cluster growth by an adiabatic expansion process. From the macroscopic viewpoint, we simulate the behavior of clusters and inert gas in the flight path under different experimental conditions. The internal energy of the cluster, which consists of rotational and vibrational energies, is limited by the binding energy which depends on the cluster size. These internal and binding energies are used as criteria of the cluster growth. The binding energy is estimated by surface and volume terms. Several types of size distribution of generated clusters under various conditions are obtained by the present model. The results of the present numerical simulations reveal that the size distribution is strongly related to the experimental conditions and can be controlled.
Ionoacoustics: A new direct method for range verification
NASA Astrophysics Data System (ADS)
Parodi, Katia; Assmann, Walter
2015-05-01
The superior ballistic properties of ion beams may offer improved tumor-dose conformality and unprecedented sparing of organs at risk in comparison to other radiation modalities in external radiotherapy. However, these advantages come at the expense of increased sensitivity to uncertainties in the actual treatment delivery, resulting from inaccuracies of patient positioning, physiological motion and uncertainties in the knowledge of the ion range in living tissue. In particular, the dosimetric selectivity of ion beams depends on the longitudinal location of the Bragg peak, making in vivo knowledge of the actual beam range the greatest challenge to full clinical exploitation of ion therapy. Nowadays, in vivo range verification techniques, which are already, or close to, being investigated in the clinical practice, rely on the detection of the secondary annihilation photons or prompt gammas, resulting from nuclear interaction of the primary ion beam with the irradiated tissue. Despite the initial promising results, these methods utilize a not straightforward correlation between nuclear and electromagnetic processes, and typically require massive and costly instrumentation. On the contrary, the long-term known, yet only recently revisited process of "ionoacoustics", which is generated by local tissue heating especially at the Bragg peak, may offer a more direct approach to in vivo range verification, as reviewed here.
DIVA: an iterative method for building modular integrated models
NASA Astrophysics Data System (ADS)
Hinkel, J.
2005-08-01
Integrated modelling of global environmental change impacts faces the challenge that knowledge from the domains of Natural and Social Science must be integrated. This is complicated by often incompatible terminology and the fact that the interactions between subsystems are usually not fully understood at the start of the project. While a modular modelling approach is necessary to address these challenges, it is not sufficient. The remaining question is how the modelled system shall be cut down into modules. While no generic answer can be given to this question, communication tools can be provided to support the process of modularisation and integration. Along those lines of thought a method for building modular integrated models was developed within the EU project DINAS-COAST and applied to construct a first model, which assesses the vulnerability of the world's coasts to climate change and sea-level-rise. The method focuses on the development of a common language and offers domain experts an intuitive interface to code their knowledge in form of modules. However, instead of rigorously defining interfaces between the subsystems at the project's beginning, an iterative model development process is defined and tools to facilitate communication and collaboration are provided. This flexible approach has the advantage that increased understanding about subsystem interactions, gained during the project's lifetime, can immediately be reflected in the model.
Integrating MCH/FP and STD/HIV services: current debates and future directions.
Mayhew, S
1996-12-01
The issue of integrating MCH/FP and STD/HIV services has gained an increasingly high priority on public health agendas in recent years. In the prevailing climate of health sector reform, policy-makers are likely to be increasingly pressed to address the broader concept of "reproductive health' in the terms consolidated at the Cairo International Conference on Population and Development, and the UN Conference on Women in Beijing. Integrated MCH/FP and STD/HIV services could be regarded as a significant step towards providing integrated reproductive health services, but clarity of issues and concerns is essential. A number of rationales have emerged which argue for the integration of these services, and many concerns have been voiced. There is little consensus, however, on the definition of "integrated services' and there are few documented case studies which might clarify the issues. This paper reviews the context in which rationales for "integrated services' emerged, the issues of concern and the case studies available. It concludes by suggesting future directions for research, noting in particular the need for country-specific and multi-dimensional frameworks and the appropriateness of a policy analysis approach.
Methods for Developing Emissions Scenarios for Integrated Assessment Models
Prinn, Ronald; Webster, Mort
2007-08-20
The overall objective of this research was to contribute data and methods to support the future development of new emissions scenarios for integrated assessment of climate change. Specifically, this research had two main objectives: 1. Use historical data on economic growth and energy efficiency changes, and develop probability density functions (PDFs) for the appropriate parameters for two or three commonly used integrated assessment models. 2. Using the parameter distributions developed through the first task and previous work, we will develop methods of designing multi-gas emission scenarios that usefully span the joint uncertainty space in a small number of scenarios. Results on the autonomous energy efficiency improvement (AEEI) parameter are summarized, an uncertainty analysis of elasticities of substitution is described, and the probabilistic emissions scenario approach is presented.
Computing thermal Wigner densities with the phase integration method
Beutier, J.; Borgis, D.; Vuilleumier, R.; Bonella, S.
2014-08-28
We discuss how the Phase Integration Method (PIM), recently developed to compute symmetrized time correlation functions [M. Monteferrante, S. Bonella, and G. Ciccotti, Mol. Phys. 109, 3015 (2011)], can be adapted to sampling/generating the thermal Wigner density, a key ingredient, for example, in many approximate schemes for simulating quantum time dependent properties. PIM combines a path integral representation of the density with a cumulant expansion to represent the Wigner function in a form calculable via existing Monte Carlo algorithms for sampling noisy probability densities. The method is able to capture highly non-classical effects such as correlation among the momenta and coordinates parts of the density, or correlations among the momenta themselves. By using alternatives to cumulants, it can also indicate the presence of negative parts of the Wigner density. Both properties are demonstrated by comparing PIM results to those of reference quantum calculations on a set of model problems.
Chen, Zhongxian; Yu, Haitao; Wen, Cheng
2014-01-01
The goal of direct drive ocean wave energy extraction system is to convert ocean wave energy into electricity. The problem explored in this paper is the design and optimal control for the direct drive ocean wave energy extraction system. An optimal control method based on internal model proportion integration differentiation (IM-PID) is proposed in this paper though most of ocean wave energy extraction systems are optimized by the structure, weight, and material. With this control method, the heavy speed of outer heavy buoy of the energy extraction system is in resonance with incident wave, and the system efficiency is largely improved. Validity of the proposed optimal control method is verified in both regular and irregular ocean waves, and it is shown that IM-PID control method is optimal in that it maximizes the energy conversion efficiency. In addition, the anti-interference ability of IM-PID control method has been assessed, and the results show that the IM-PID control method has good robustness, high precision, and strong anti-interference ability. PMID:25152913
Chen, Zhongxian; Yu, Haitao; Wen, Cheng
2014-01-01
The goal of direct drive ocean wave energy extraction system is to convert ocean wave energy into electricity. The problem explored in this paper is the design and optimal control for the direct drive ocean wave energy extraction system. An optimal control method based on internal model proportion integration differentiation (IM-PID) is proposed in this paper though most of ocean wave energy extraction systems are optimized by the structure, weight, and material. With this control method, the heavy speed of outer heavy buoy of the energy extraction system is in resonance with incident wave, and the system efficiency is largely improved. Validity of the proposed optimal control method is verified in both regular and irregular ocean waves, and it is shown that IM-PID control method is optimal in that it maximizes the energy conversion efficiency. In addition, the anti-interference ability of IM-PID control method has been assessed, and the results show that the IM-PID control method has good robustness, high precision, and strong anti-interference ability.
ERIC Educational Resources Information Center
Liebowitz, Steven E.
This paper introduces the Pause Model, an innovative means of integrating self-directed learning and continuing professional education. Since the method was developed for professionals such as counselors, educators, and managers who practice in social settings, the paper begins with an explanation of a few of the unique attributes of professional…
Servo-integrated patterned media by hybrid directed self-assembly.
Xiao, Shuaigang; Yang, Xiaomin; Steiner, Philip; Hsu, Yautzong; Lee, Kim; Wago, Koichi; Kuo, David
2014-11-25
A hybrid directed self-assembly approach is developed to fabricate unprecedented servo-integrated bit-patterned media templates, by combining sphere-forming block copolymers with 5 teradot/in.(2) resolution capability, nanoimprint and optical lithography with overlay control. Nanoimprint generates prepatterns with different dimensions in the data field and servo field, respectively, and optical lithography controls the selective self-assembly process in either field. Two distinct directed self-assembly techniques, low-topography graphoepitaxy and high-topography graphoepitaxy, are elegantly integrated to create bit-patterned templates with flexible embedded servo information. Spinstand magnetic test at 1 teradot/in.(2) shows a low bit error rate of 10(-2.43), indicating fully functioning bit-patterned media and great potential of this approach for fabricating future ultra-high-density magnetic storage media.
Adaptive temporal integration of motion in direction-selective neurons in macaque visual cortex.
Bair, Wyeth; Movshon, J Anthony
2004-08-18
Direction-selective neurons in the primary visual cortex (V1) and the extrastriate motion area MT/V5 constitute a critical channel that links early cortical mechanisms of spatiotemporal integration to downstream signals that underlie motion perception. We studied how temporal integration in direction-selective cells depends on speed, spatial frequency (SF), and contrast using randomly moving sinusoidal gratings and spike-triggered average (STA) analysis. The window of temporal integration revealed by the STAs varied substantially with stimulus parameters, extending farther back in time for slow motion, high SF, and low contrast. At low speeds and high SF, STA peaks were larger, indicating that a single spike often conveyed more information about the stimulus under conditions in which the mean firing rate was very low. The observed trends were similar in V1 and MT and offer a physiological correlate for a large body of psychophysical data on temporal integration. We applied the same visual stimuli to a model of motion detection based on oriented linear filters (a motion energy model) that incorporated an integrate-and-fire mechanism and found that it did not account for the neuronal data. Our results show that cortical motion processing in V1 and in MT is highly nonlinear and stimulus dependent. They cast considerable doubt on the ability of simple oriented filter models to account for the output of direction-selective neurons in a general manner. Finally, they suggest that spike rate tuning functions may miss important aspects of the neural coding of motion for stimulus conditions that evoke low firing rates. PMID:15317857
Direct comparison of unloading compliance and potential drop techniques in J-integral testing
McGowan, J.J.; Nanstad, R.K.
1984-01-01
Single-specimen J-integral testing is performed commonly with the unloading compliance technique. Use of modern instrumentation techniques and powerful desktop computers have made this technique a standard. However, this testing technique is slow and tedious, with the loading rate fixed at a slow quasi-static rate. For these reasons the dc potential drop technique was investigated for crack length measurement during a J-integral test. For direct comparison, both unloading compliance and potential drop were used simultaneously during a J-integral test. The results showed good agreement between the techniques. However, the potential drop technique showed an offset in crack length due to plastic blunting processes. Taking this offset into account, J/sub Ic/ values calculated by both techniques compared well.
A simple and direct method for generating travelling wave solutions for nonlinear equations
Bazeia, D. Das, Ashok; Silva, A.
2008-05-15
We propose a simple and direct method for generating travelling wave solutions for nonlinear integrable equations. We illustrate how nontrivial solutions for the KdV, the mKdV and the Boussinesq equations can be obtained from simple solutions of linear equations. We describe how using this method, a soliton solution of the KdV equation can yield soliton solutions for the mKdV as well as the Boussinesq equations. Similarly, starting with cnoidal solutions of the KdV equation, we can obtain the corresponding solutions for the mKdV as well as the Boussinesq equations. Simple solutions of linear equations can also lead to cnoidal solutions of nonlinear systems. Finally, we propose and solve some new families of KdV equations and show how soliton solutions are also obtained for the higher order equations of the KdV hierarchy using this method.
1980-10-15
Version 00 PALLAS-2DCY-FX is a code for direct integration of the transport equation in two-dimensional (r,z) geometry. It solves the energy and angular-dependent Boltzmann transport equation with general anisotropic scattering in cylindrical geometry. Its principal applications are to neutron or gamma-ray transport problems in the forward mode. The code is particularly designed for and suited to the solution of deep penetration radiation transport problems with an external (fixed) source.
Advances in directed self assembly integration and manufacturability at 300 mm
NASA Astrophysics Data System (ADS)
Rathsack, Benjamen; Somervell, Mark; Muramatsu, Makato; Tanouchi, Keiji; Kitano, Takahiro; Nishimura, Eiichi; Yatsuda, Koichi; Nagahara, Seiji; Iwaki, Hiroyuki; Akai, Keiji; Ozawa, Mariko; Romo Negreira, Ainhoa; Tahara, Shigeru; Nafus, Kathleen
2013-03-01
Directed self-assembly (DSA) has the potential to extend scaling for both line/space and hole patterns. DSA has shown the capability for pitch reduction (multiplication), hole shrinks, CD self-healing as well as a pathway towards LWR and pattern collapse improvement [1-10]. TEL has developed a DSA development ecosystem (collaboration with customers, consortia, inspection vendors and material suppliers) to successfully demonstrate directed PS-PMMA DSA patterns using chemo-epitaxy (lift-off and etch guide) and grapho-epitaxy integrations on 300 mm wafers. New processes are being developed to simplify process integration, to reduce defects and to address design integration challenges with the long term goal of robust manufacturability. For hole DSA applications, a wet development process has been developed that enables traditional post-develop metrology through the high selectivity removal of PMMA cylindrical cores. For line/ space DSA applications, new track, cleans and etch processes have been developed to improve manufacturability. In collaboration with universities and consortia, fundamental process studies and simulations are used to drive process improvement and defect investigation. To extend DSA resolution beyond a PS-PMMA system, high chi materials and processes are also explored. In this paper, TEL's latest process solutions for both hole and line/space DSA process integrations are presented.
AI/OR computational model for integrating qualitative and quantitative design methods
NASA Technical Reports Server (NTRS)
Agogino, Alice M.; Bradley, Stephen R.; Cagan, Jonathan; Jain, Pramod; Michelena, Nestor
1990-01-01
A theoretical framework for integrating qualitative and numerical computational methods for optimally-directed design is described. The theory is presented as a computational model and features of implementations are summarized where appropriate. To demonstrate the versatility of the methodology we focus on four seemingly disparate aspects of the design process and their interaction: (1) conceptual design, (2) qualitative optimal design, (3) design innovation, and (4) numerical global optimization.
Method for integrating microelectromechanical devices with electronic circuitry
Montague, S.; Smith, J.H.; Sniegowski, J.J.; McWhorter, P.J.
1998-08-25
A method is disclosed for integrating one or more microelectromechanical (MEM) devices with electronic circuitry. The method comprises the steps of forming each MEM device within a cavity below a device surface of the substrate; encapsulating the MEM device prior to forming electronic circuitry on the substrate; and releasing the MEM device for operation after fabrication of the electronic circuitry. Planarization of the encapsulated MEM device prior to formation of the electronic circuitry allows the use of standard processing steps for fabrication of the electronic circuitry. 13 figs.
Method for integrating microelectromechanical devices with electronic circuitry
Montague, Stephen; Smith, James H.; Sniegowski, Jeffry J.; McWhorter, Paul J.
1998-01-01
A method for integrating one or more microelectromechanical (MEM) devices with electronic circuitry. The method comprises the steps of forming each MEM device within a cavity below a device surface of the substrate; encapsulating the MEM device prior to forming electronic circuitry on the substrate; and releasing the MEM device for operation after fabrication of the electronic circuitry. Planarization of the encapsulated MEM device prior to formation of the electronic circuitry allows the use of standard processing steps for fabrication of the electronic circuitry.
Synthesis of aircraft structures using integrated design and analysis methods
NASA Technical Reports Server (NTRS)
Sobieszczanski-Sobieski, J.; Goetz, R. C.
1978-01-01
A systematic research is reported to develop and validate methods for structural sizing of an airframe designed with the use of composite materials and active controls. This research program includes procedures for computing aeroelastic loads, static and dynamic aeroelasticity, analysis and synthesis of active controls, and optimization techniques. Development of the methods is concerned with the most effective ways of integrating and sequencing the procedures in order to generate structural sizing and the associated active control system, which is optimal with respect to a given merit function constrained by strength and aeroelasticity requirements.
Electrochemical synthesis of nanosized hydroxyapatite by pulsed direct current method
Nur, Adrian; Rahmawati, Alifah; Ilmi, Noor Izzati; Affandi, Samsudin; Widjaja, Arief
2014-02-24
Synthesis of nanosized of hydroxyapatite (HA) by electrochemical pulsed direct current (PDC) method has been studied. The aim of this work is to study the influence of various PDC parameters (pH initial, electrode distance, duty cycle, frequency, and amplitude) on particle surface area of HA powders. The electrochemical synthesis was prepared in solution Ca{sup 2+}/EDTA{sup 4−}/PO{sub 4}{sup 3+} at concentration 0.25/0.25/0.15 M for 24 h. The electrochemical cell was consisted of two carbon rectangular electrodes connected to a function generator to produce PDC. There were two treatments for particles after electrosynthesized, namely without aging and aged for 2 days at 40 °C. For both cases, the particles were filtered and washed by demineralized water to eliminate the impurities and unreacted reactants. Then, the particles were dried at 100 °C for 2 days. The dried particles were characterized by X-ray diffraction, surface area analyzer, scanning electron microscopy (SEM), Fourier transform infrared spectra and thermogravimetric and differential thermal analysis. HA particles can be produced when the initial pH > 6. The aging process has significant effect on the produced HA particles. SEM images of HA particles showed that the powders consisted of agglomerates composed of fine crystallites and have morphology plate-like and sphere. The surface area of HA particles is in the range of 25 – 91 m{sup 2}/g. The largest particle surface area of HA was produced at 4 cm electrode distance, 80% cycle duty, frequency 0.1 Hz, amplitude 9 V and with aging process.
Method and apparatus for determining material structural integrity
Pechersky, Martin
1996-01-01
A non-destructive method and apparatus for determining the structural integrity of materials by combining laser vibrometry with damping analysis techniques to determine the damping loss factor of a material. The method comprises the steps of vibrating the area being tested over a known frequency range and measuring vibrational force and velocity as a function of time over the known frequency range. Vibrational velocity is preferably measured by a laser vibrometer. Measurement of the vibrational force depends on the vibration method. If an electromagnetic coil is used to vibrate a magnet secured to the area being tested, then the vibrational force is determined by the amount of coil current used in vibrating the magnet. If a reciprocating transducer is used to vibrate a magnet secured to the area being tested, then the vibrational force is determined by a force gauge in the reciprocating transducer. Using known vibrational analysis methods, a plot of the drive point mobility of the material over the preselected frequency range is generated from the vibrational force and velocity measurements. The damping loss factor is derived from a plot of the drive point mobility over the preselected frequency range using the resonance dwell method and compared with a reference damping loss factor for structural integrity evaluation.
Variational methods for direct/inverse problems of atmospheric dynamics and chemistry
NASA Astrophysics Data System (ADS)
Penenko, Vladimir; Penenko, Alexey; Tsvetova, Elena
2013-04-01
We present a variational approach for solving direct and inverse problems of atmospheric hydrodynamics and chemistry. It is important that the accurate matching of numerical schemes has to be provided in the chain of objects: direct/adjoint problems - sensitivity relations - inverse problems, including assimilation of all available measurement data. To solve the problems we have developed a new enhanced set of cost-effective algorithms. The matched description of the multi-scale processes is provided by a specific choice of the variational principle functionals for the whole set of integrated models. Then all functionals of variational principle are approximated in space and time by splitting and decomposition methods. Such approach allows us to separately consider, for example, the space-time problems of atmospheric chemistry in the frames of decomposition schemes for the integral identity sum analogs of the variational principle at each time step and in each of 3D finite-volumes. To enhance the realization efficiency, the set of chemical reactions is divided on the subsets related to the operators of production and destruction. Then the idea of the Euler's integrating factors is applied in the frames of the local adjoint problem technique [1]-[3]. The analytical solutions of such adjoint problems play the role of integrating factors for differential equations describing atmospheric chemistry. With their help, the system of differential equations is transformed to the equivalent system of integral equations. As a result we avoid the construction and inversion of preconditioning operators containing the Jacobi matrixes which arise in traditional implicit schemes for ODE solution. This is the main advantage of our schemes. At the same time step but on the different stages of the "global" splitting scheme, the system of atmospheric dynamic equations is solved. For convection - diffusion equations for all state functions in the integrated models we have developed the
Neocartilage integration in temporomandibular joint discs: physical and enzymatic methods
Murphy, Meghan K.; Arzi, Boaz; Prouty, Shannon M.; Hu, Jerry C.; Athanasiou, Kyriacos A.
2015-01-01
Integration of engineered musculoskeletal tissues with adjacent native tissues presents a significant challenge to the field. Specifically, the avascularity and low cellularity of cartilage elicit the need for additional efforts in improving integration of neocartilage within native cartilage. Self-assembled neocartilage holds significant potential in replacing degenerated cartilage, though its stabilization and integration in native cartilage require further efforts. Physical and enzymatic stabilization methods were investigated in an in vitro model for temporomandibular joint (TMJ) disc degeneration. First, in phase 1, suture, glue and press-fit constructs were compared in TMJ disc intermediate zone defects. In phase 1, suturing enhanced interfacial shear stiffness and strength immediately; after four weeks, a 15-fold increase in stiffness and a ninefold increase in strength persisted over press-fit. Neither suture nor glue significantly altered neocartilage properties. In phase 2, the effects of the enzymatic stabilization regimen composed of lysyl oxidase, CuSO4 and hydroxylysine were investigated. A full factorial design was employed, carrying forward the best physical method from phase 1, suturing. Enzymatic stabilization significantly increased interfacial shear stiffness after eight weeks. Combined enzymatic stabilization and suturing led to a fourfold increase in shear stiffness and threefold increase in strength over press-fit. Histological analysis confirmed the presence of a collagen-rich interface. Enzymatic treatment additionally enhanced neocartilage mechanical properties, yielding a tensile modulus over 6 MPa and compressive instantaneous modulus over 1200 kPa at eight weeks. Suturing enhances stabilization of neocartilage, and enzymatic treatment enhances functional properties and integration of neocartilage in the TMJ disc. Methods developed here are applicable to other orthopaedic soft tissues, including knee meniscus and hyaline articular
Methods for integration of transcriptomic data in genome-scale metabolic models
Kim, Min Kyung; Lun, Desmond S.
2014-01-01
Several computational methods have been developed that integrate transcriptomic data with genome-scale metabolic reconstructions to infer condition-specific system-wide intracellular metabolic flux distributions. In this mini-review, we describe each of these methods published to date with categorizing them based on four different grouping criteria (requirement for multiple gene expression datasets as input, requirement for a threshold to define a gene's high and low expression, requirement for a priori assumption of an appropriate objective function, and validation of predicted fluxes directly against measured intracellular fluxes). Then, we recommend which group of methods would be more suitable from a practical perspective. PMID:25379144
Efficient Fully Implicit Time Integration Methods for Modeling Cardiac Dynamics
Rose, Donald J.; Henriquez, Craig S.
2013-01-01
Implicit methods are well known to have greater stability than explicit methods for stiff systems, but they often are not used in practice due to perceived computational complexity. This paper applies the Backward Euler method and a second-order one-step two-stage composite backward differentiation formula (C-BDF2) for the monodomain equations arising from mathematically modeling the electrical activity of the heart. The C-BDF2 scheme is an L-stable implicit time integration method and easily implementable. It uses the simplest Forward Euler and Backward Euler methods as fundamental building blocks. The nonlinear system resulting from application of the Backward Euler method for the monodomain equations is solved for the first time by a nonlinear elimination method, which eliminates local and non-symmetric components by using a Jacobian-free Newton solver, called Newton-Krylov solver. Unlike other fully implicit methods proposed for the monodomain equations in the literature, the Jacobian of the global system after the nonlinear elimination has much smaller size, is symmetric and possibly positive definite, which can be solved efficiently by standard optimal solvers. Numerical results are presented demonstrating that the C-BDF2 scheme can yield accurate results with less CPU times than explicit methods for both a single patch and spatially extended domains. PMID:19126449
NASA Technical Reports Server (NTRS)
Yu, F. P.; Pyle, B. H.; McFeters, G. A.
1993-01-01
This report describes the adaptation of an in situ direct viable count (in situ DVC) method in biofilm disinfection studies. The results obtained with this technique were compared to two other enumeration methods, the plate count (PC) and conventional direct viable count (c-DVC). An environmental isolate (Klebsiella pneumoniae Kp1) was used to form biofilms on stainless steel coupons in a stirred batch reactor. The in situ DVC method was applied to directly assess the viability of bacteria in biofilms without disturbing the integrity of the interfacial community. As additional advantages, the results were observed after 4 h instead of the 24 h incubation time required for colony formation and total cell numbers that remained on the substratum were enumerated. Chlorine and monochloramine were used to determine the susceptibilities of attached and planktonic bacteria to disinfection treatment using this novel analytical approach. The planktonic cells in the reactor showed no significant change in susceptibility to disinfectants during the period of biofilm formation. In addition, the attached cells did not reveal any more resistance to disinfection than planktonic cells. The disinfection studies of young biofilms indicated that 0.25 mg/l free chlorine (at pH 7.2) and 1 mg/l monochloramine (at pH 9.0) have comparable disinfection efficiencies at 25 degrees C. Although being a weaker disinfectant, monochloramine was more effective in removing attached bacteria from the substratum than free chlorine. The in situ DVC method always showed at least one log higher viable cell densities than the PC method, suggesting that the in situ DVC method is more efficient in the enumeration of biofilm bacteria. The results also indicated that the in situ DVC method can provide more accurate information regarding the cell numbers and viability of bacteria within biofilms following disinfection.
An inverse method was developed to integrate satellite observations of atmospheric pollutant column concentrations and direct sensitivities predicted by a regional air quality model in order to discern biases in the emissions of the pollutant precursors.
Micro-spec: an Integrated Direct-detection Spectrometer for Far-infrared Space Telescopes
NASA Technical Reports Server (NTRS)
Cataldo, Giuseppe; Hsieh, Wen-Ting; Huang, Wei-Chung; Moseley, S. Harvey; Stevenson, Thomas R.; Wollack, Edward J.
2014-01-01
The far-infrared and submillimeter portions of the electromagnetic spectrum provide a unique view of the astrophysical processes present in the early universe. Our ability to fully explore this rich spectral region has been limited, however, by the size and cost of the cryogenic spectrometers required to carry out such measurements.Micro-Spec (µ-Spec) is a high-sensitivity, direct-detection spectrometer concept working in the 450-1000 (micrometers) wavelength range which will enable a wide range of flight missions that would otherwise be challenging due tothe large size of current instruments with the required spectral resolution and sensitivity. The spectrometer design utilizes two internal antenna arrays, one for transmitting and one for receiving, superconducting microstrip transmission lines for power division and phase delay, and an array of microwave kinetic inductance detectors (MKIDs) to achieve these goals. The instrument will be integrated on a approximately 10 sq cm silicon chip and can therefore become an important capability under the low background conditions accessible via space and high-altitude borne platforms. In this paper, an optical design methodology for micro-Spec is presented, with particular attention given to its two-dimensional diffractive region, where the light of different wavelengths is focused on the different detectors. The method is based on the maximization of the instrument resolving power and minimization of the RMS phase error on the instrument focal plane. This two-step optimization can generate geometrical configurations given specific requirements on spectrometer size, operating spectral range and performance.Two point designs with resolving power of 260 and 520 and an RMS phase error less than approximately 0.004 radians were developed for initial demonstration and will be the basis of future instruments with resolving power up to about 1200.
Antenna-integrated 0.6 THz FET direct detectors based on CVD graphene.
Zak, Audrey; Andersson, Michael A; Bauer, Maris; Matukas, Jonas; Lisauskas, Alvydas; Roskos, Hartmut G; Stake, Jan
2014-10-01
We present terahertz (THz) detectors based on top-gated graphene field effect transistors (GFETs) with integrated split bow-tie antennas. The GFETs were fabricated using graphene grown by chemical vapor deposition (CVD). The THz detectors are capable of room-temperature rectification of a 0.6 THz signal and achieve a maximum optical responsivity better than 14 V/W and minimum optical noise-equivalent power (NEP) of 515 pW/Hz(0.5). Our results are a significant improvement over previous work on graphene direct detectors and are comparable to other established direct detector technologies. This is the first time room-temperature direct detection has been demonstrated using CVD graphene, which introduces the potential for scalable, wafer-level production of graphene detectors. PMID:25203787
Extrapolation of critical Rayleigh values using static nodal integral methods
Wilson, G.L.; Rydin, R.A.
1988-01-01
The Benard problem is the study of the convective motion of a fluid in a rectangular cavity that is uniformly heated form below. Flow bifurcation in the cavity is a function of the Rayleigh number (Ra). The time-dependent nodal integral method (TDNIM) has been reported previously; its development leads to a set of 11 equations per node. The static nodal integral method (SNIM) was derived from the TDNIM by forcing the dependent variable at adjacent time steps (one of the velocity components or temperature) to take on the node integral average value. The paper summarizes the SNIM calculation of Ra for mesh sizes ranging from 4 x 4 to 24 x 24. The numerical calculation of Ra is within plus or minus one-half unit. The relative errors are calculated based on the obtained extrapolated value of Ra{sub best}* = 2584. The paper also summarizes three-point schemes used with increasingly finer mesh combinations. This approach avoids the contamination of the results with a coarse mesh; however, the calculation on n is very sensitive to small changes in the numerical values obtained for Ra*. In this approach, the extrapolated values quickly converge to Ra*{sub e} between 2583 and 2584 with n {approx}2.0 as desired, and give a best value of Ra*{sub best} = 2584.
New method for evaluating antibacterial activity directly on fabric.
Lashen, E S
1971-04-01
Bacteriostasis of treated fabric was evaluated directly by a colony count made on the treated fabric after impregnation with seeded agar containing triphenyltetrazolium chloride and incubation in a horizontal, suspended position in a petri dish.
Integration of Directional Antennas in an RSS Fingerprinting-Based Indoor Localization System.
Guzmán-Quirós, Raúl; Martínez-Sala, Alejandro; Gómez-Tornero, José Luis; García-Haro, Joan
2015-12-23
In this paper, the integration of directional antennas in a room-level received signal strength (RSS) fingerprinting-based indoor localization system (ILS) is studied. The sensor reader (SR), which is in charge of capturing the RSS to infer the tag position, can be attached to an omnidirectional or directional antenna. Unlike commonly-employed omnidirectional antennas, directional antennas can receive a stronger signal from the direction in which they are pointed, resulting in a different RSS distributions in space and, hence, more distinguishable fingerprints. A simulation tool and a system management software have been also developed to control the system and assist the initial antenna deployment, reducing time-consuming costs. A prototype was mounted in a real scenario, with a number of SRs with omnidirectional and directional antennas properly positioned. Different antenna configurations have been studied, evidencing a promising capability of directional antennas to enhance the performance of RSS fingerprinting-based ILS, reducing the number of required SRs and also increasing the localization success.
Integration of Directional Antennas in an RSS Fingerprinting-Based Indoor Localization System
Guzmán-Quirós, Raúl; Martínez-Sala, Alejandro; Gómez-Tornero, José Luis; García-Haro, Joan
2015-01-01
In this paper, the integration of directional antennas in a room-level received signal strength (RSS) fingerprinting-based indoor localization system (ILS) is studied. The sensor reader (SR), which is in charge of capturing the RSS to infer the tag position, can be attached to an omnidirectional or directional antenna. Unlike commonly-employed omnidirectional antennas, directional antennas can receive a stronger signal from the direction in which they are pointed, resulting in a different RSS distributions in space and, hence, more distinguishable fingerprints. A simulation tool and a system management software have been also developed to control the system and assist the initial antenna deployment, reducing time-consuming costs. A prototype was mounted in a real scenario, with a number of SRs with omnidirectional and directional antennas properly positioned. Different antenna configurations have been studied, evidencing a promising capability of directional antennas to enhance the performance of RSS fingerprinting-based ILS, reducing the number of required SRs and also increasing the localization success. PMID:26703620
Integrated Force Method Solution to Indeterminate Structural Mechanics Problems
NASA Technical Reports Server (NTRS)
Patnaik, Surya N.; Hopkins, Dale A.; Halford, Gary R.
2004-01-01
Strength of materials problems have been classified into determinate and indeterminate problems. Determinate analysis primarily based on the equilibrium concept is well understood. Solutions of indeterminate problems required additional compatibility conditions, and its comprehension was not exclusive. A solution to indeterminate problem is generated by manipulating the equilibrium concept, either by rewriting in the displacement variables or through the cutting and closing gap technique of the redundant force method. Compatibility improvisation has made analysis cumbersome. The authors have researched and understood the compatibility theory. Solutions can be generated with equal emphasis on the equilibrium and compatibility concepts. This technique is called the Integrated Force Method (IFM). Forces are the primary unknowns of IFM. Displacements are back-calculated from forces. IFM equations are manipulated to obtain the Dual Integrated Force Method (IFMD). Displacement is the primary variable of IFMD and force is back-calculated. The subject is introduced through response variables: force, deformation, displacement; and underlying concepts: equilibrium equation, force deformation relation, deformation displacement relation, and compatibility condition. Mechanical load, temperature variation, and support settling are equally emphasized. The basic theory is discussed. A set of examples illustrate the new concepts. IFM and IFMD based finite element methods are introduced for simple problems.
Integral structural-functional method for characterizing microbial populations
NASA Astrophysics Data System (ADS)
Yakushev, A. V.
2015-04-01
An original integral structural-functional method has been proposed for characterizing microbial communities. The novelty of the approach is the in situ study of microorganisms based on the growth kinetics of microbial associations in liquid nutrient broth media under selective conditions rather than on the level of taxa or large functional groups. The method involves the analysis of the integral growth model of a periodic culture. The kinetic parameters of such associations reflect their capacity of growing on different media, i.e., their physiological diversity, and the metabolic capacity of the microorganisms for growth on a nutrient medium. Therefore, the obtained parameters are determined by the features of the microbial ecological strategies. The inoculation of a dense medium from the original inoculate allows characterizing the taxonomic composition of the dominants in the soil community. The inoculation from the associations developed on selective media characterizes the composition of syntrophic groups, which fulfill a specific function in nature. This method is of greater information value than the classical methods of inoculation on selective media.
Method and apparatus for determining material structural integrity
Pechersky, M.J.
1994-01-01
Disclosed are a nondestructive method and apparatus for determining the structural integrity of materials by combining laser vibrometry with damping analysis to determine the damping loss factor. The method comprises the steps of vibrating the area being tested over a known frequency range and measuring vibrational force and velocity vs time over the known frequency range. Vibrational velocity is preferably measured by a laser vibrometer. Measurement of the vibrational force depends on the vibration method: if an electromagnetic coil is used to vibrate a magnet secured to the area being tested, then the vibrational force is determined by the coil current. If a reciprocating transducer is used, the vibrational force is determined by a force gauge in the transducer. Using vibrational analysis, a plot of the drive point mobility of the material over the preselected frequency range is generated from the vibrational force and velocity data. Damping loss factor is derived from a plot of the drive point mobility over the preselected frequency range using the resonance dwell method and compared with a reference damping loss factor for structural integrity evaluation.
NASA Astrophysics Data System (ADS)
Isaenkova, M.; Perlovich, Yu; Fesenko, V.
2016-04-01
Currently used methods for constructing texture complete direct pole figure (CDPF) based on the results of X-ray diffractometric measurements were considered with respect to the products of Zr-based alloys and, in particular, used in a nuclear reactor cladding tubes, for which the accuracy of determination of integral texture parameters is of the especial importance. The main attention was devoted to technical issues which are solved by means of computer processing of large arrays of obtained experimental data. Among considered questions there are amendments of the defocusing, techniques for constructing of complete direct pole figures and determination of integral textural parameters. The methods of reconstruction of complete direct pole figures by partial direct pole figures recorded up to tilt angles of sample ψ=70-80°: the method of extrapolation of data to an uninvestigated region of the stereographic projection, and the method of "sewing" of partial pole figures measured for three mutually perpendicular plane sections of the product. The limits of applicability of these methods, depending on the shape of the test product and the degree of inhomogeneity of the layer-by-layer texture, were revealed. On the basis of a large number of experimental data, the accuracy of the integral parameters used for calculation of the physical and mechanical properties of metals with a hexagonal crystal structure was found to be equal to 0.02, when taking into account the texture heterogeneity of regular products from Zr-based alloys.
NASA Astrophysics Data System (ADS)
Cho, Jaepil; Shin, Chang-Min; Choi, Hwan-Kyu; Kim, Kyong-Hyeon; Choi, Ji-Yong
2016-10-01
The APEC Climate Center (APCC) produces climate prediction information utilizing a multi-climate model ensemble (MME) technique. In this study, four different downscaling methods, in accordance with the degree of utilizing the seasonal climate prediction information, were developed in order to improve predictability and to refine the spatial scale. These methods include: (1) the Simple Bias Correction (SBC) method, which directly uses APCC's dynamic prediction data with a 3 to 6 month lead time; (2) the Moving Window Regression (MWR) method, which indirectly utilizes dynamic prediction data; (3) the Climate Index Regression (CIR) method, which predominantly uses observation-based climate indices; and (4) the Integrated Time Regression (ITR) method, which uses predictors selected from both CIR and MWR. Then, a sampling-based temporal downscaling was conducted using the Mahalanobis distance method in order to create daily weather inputs to the Soil and Water Assessment Tool (SWAT) model. Long-term predictability of water quality within the Wecheon watershed of the Nakdong River Basin was evaluated. According to the Korean Ministry of Environment's Provisions of Water Quality Prediction and Response Measures, modeling-based predictability was evaluated by using 3-month lead prediction data issued in February, May, August, and November as model input of SWAT. Finally, an integrated approach, which takes into account various climate information and downscaling methods for water quality prediction, was presented. This integrated approach can be used to prevent potential problems caused by extreme climate in advance.
Pattern scaling with directed self assembly through lithography and etch process integration
NASA Astrophysics Data System (ADS)
Rathsack, Benjamen; Somervell, Mark; Hooge, Josh; Muramatsu, Makoto; Tanouchi, Keiji; Kitano, Takahiro; Nishimura, Eiichi; Yatsuda, Koichi; Nagahara, Seiji; Hiroyuki, Iwaki; Akai, Keiji; Hayakawa, Takashi
2012-03-01
Directed self-assembly (DSA) has the potential to extend scaling for both line/space and hole patterns. DSA has shown the capability for pitch reduction (multiplication), hole shrinks, CD self-healing as well as a pathway towards line edge roughness (LER) and pattern collapse improvement [1-4]. The current challenges for industry adoption are materials maturity, practical process integration, hardware capability, defect reduction and design integration. Tokyo Electron (TEL) has created close collaborations with customers, consortia and material suppliers to address these challenges with the long term goal of robust manufacturability. This paper provides a wide range of DSA demonstrations to accommodate different device applications. In collaboration with IMEC, directed line/space patterns at 12.5 and 14 nm HP are demonstrated with PS-b-PMMA (poly(styrene-b-methylmethacrylate)) using both chemo and grapho-epitaxy process flows. Pre-pattern exposure latitudes of >25% (max) have been demonstrated with 4X directed self-assembly on 300 mm wafers for both the lift off and etch guide chemo-epitaxy process flows. Within TEL's Technology Development Center (TDC), directed selfassembly processes have been applied to holes for both CD shrink and variation reduction. Using a PS-b-PMMA hole shrink process, negative tone developed pre-pattern holes are reduced to below 30 nm with critical dimension uniformity (CDU) of 0.9 nm (3s) and contact edge roughness (CER) of 0.8 nm. To generate higher resolution beyond a PS-b-PMMA system, a high chi material is used to demonstrate 9 nm HP line/ space post-etch patterns. In this paper, TEL presents process solutions for both line/space and hole DSA process integrations.
Inhomogeneous Media 3D EM Modeling with Integral Equation Method
NASA Astrophysics Data System (ADS)
di, Q.; Wang, R.; An, Z.; Fu, C.; Xu, C.
2010-12-01
In general, only the half space of earth is considered in electromagnetic exploration. However, for the long bipole source, because the length is close to the height of ionosphere and also most offsets between source and receivers are equal or larger than the height of ionosphere, the effect of ionosphere on the electromagnetic (EM) field should be considered when observation is carried at a very far (about several thousands kilometers) location away from the source. At this point the problem becomes one which should contain ionosphere, atmosphere and earth that is “earth-ionosphere” case. There are a few of literatures to report the electromagnetic field results which is including ionosphere, atmosphere and earth media at the same time. We firstly calculate the electromagnetic fields with the traditional controlled source (CSEM) configuration using integral equation (IE) method for a three layers earth-ionosphere model. The modeling results agree well with the half space analytical results because the effect of ionosphere for this small scale bipole source can be ignorable. The comparison of small scale three layers earth-ionosphere modeling and half space analytical resolution shows that the IE method can be used to modeling the EM fields for long bipole large offset configuration. In order to discuss EM fields’ characteristics for complicate earth-ionosphere media excited by long bipole source in the far-field and wave-guide zones, we first modeled the decay characters of electromagnetic fields for three layers earth-ionosphere model. Because of the effect of ionosphere, the earth-ionosphere electromagnetic fields’ decay curves with given frequency show that there should be an extra wave guide zone for long bipole artificial source, and there are many different characters between this extra zone and far field zone. They are: 1) the amplitudes of EM fields decay much slower; 2) the polarization patterns change; 3) the positions better to measure Zxy and
Application of the boundary integral method to immiscible displacement problems
Masukawa, J.; Horne, R.N.
1988-08-01
This paper presents an application of the boundary integral method (BIM) to fluid displacement problems to demonstrate its usefulness in reservoir simulation. A method for solving two-dimensional (2D), piston-like displacement for incompressible fluids with good accuracy has been developed. Several typical example problems with repeated five-spot patterns were solved for various mobility ratios. The solutions were compared with the analytical solutions to demonstrate accuracy. Singularity programming was found to be a major advantage in handling flow in the vicinity of wells. The BIM was found to be an excellent way to solve immiscible displacement problems. Unlike analytic methods, it can accommodate complex boundary shapes and does not suffer from numerical dispersion at the front.
NASA Astrophysics Data System (ADS)
Masychev, Victor I.
2000-11-01
In this research we present the results of approbation of two methods of optical caries diagnostics: PNC-spectral diagnostics and caries detection by laser integral fluorescence. The research was conducted in a dental clinic. PNC-method analyses parameters of probing laser radiation and PNC-spectrums of stimulated secondary radiations: backscattering and endogenous fluorescence of caries-involved bacterias. He-Ne-laser ((lambda) =632,8 nm, 1-2mW) was used as a source of probing (stimulated) radiation. For registration of signals, received from intact and pathological teeth PDA-detector was applied. PNC-spectrums were processed by special algorithms, and were displayed on PC monitor. The method of laser integral fluorescence was used for comparison. In this case integral power of fluorescence of human teeth was measured. As a source of probing (stimulated) radiation diode lasers ((lambda) =655 nm, 0.1 mW and 630nm, 1mW) and He-Ne laser were applied. For registration of signals Si-photodetector was used. Integral power was shown in a digital indicator. Advantages and disadvantages of these methods are described in this research. It is disclosed that the method of laser integral power of fluorescence has the following characteristics: simplicity of construction and schema-technical decisions. However the method of PNC-spectral diagnostics are characterized by considerably more sensitivity in diagnostics of initial caries and capability to differentiate pathologies of various stages (for example, calculus/initial caries). Estimation of spectral characteristics of PNC-signals allows eliminating a number of drawbacks, which are character for detection by method of laser integral fluorescence (for instance, detection of fluorescent fillings, plagues, calculus, discolorations generally, amalgam, gold fillings as if it were caries.
Improved parallel solution techniques for the integral transport matrix method
Zerr, Robert J; Azmy, Yousry Y
2010-11-23
Alternative solution strategies to the parallel block Jacobi (PBJ) method for the solution of the global problem with the integral transport matrix method operators have been designed and tested. The most straightforward improvement to the Jacobi iterative method is the Gauss-Seidel alternative. The parallel red-black Gauss-Seidel (PGS) algorithm can improve on the number of iterations and reduce work per iteration by applying an alternating red-black color-set to the subdomains and assigning multiple sub-domains per processor. A parallel GMRES(m) method was implemented as an alternative to stationary iterations. Computational results show that the PGS method can improve on the PBJ method execution by up to {approx}50% when eight sub-domains per processor are used. However, compared to traditional source iterations with diffusion synthetic acceleration, it is still approximately an order of magnitude slower. The best-performing case are opticaUy thick because sub-domains decouple, yielding faster convergence. Further tests revealed that 64 sub-domains per processor was the best performing level of sub-domain division. An acceleration technique that improves the convergence rate would greatly improve the ITMM. The GMRES(m) method with a diagonal block preconditioner consumes approximately the same time as the PBJ solver but could be improved by an as yet undeveloped, more efficient preconditioner.
Integral wave-migration method applied to electromagnetic data
Bartel, L.C.
1994-12-31
Migration of the electromagnetic (EM) wave field will be discussed as a solution of the wave equation in which surface magnetic field measurements are the known boundary values. This approach is similar to classical optical diffraction theory. Here data is taken on a aperture, migrated (extrapolated), and deconvolved with a source function. The EM image is formed when the imaginary part of the Fourier transformed migrated field at time zero is zero or at least a minimum. The integral formulation for migration is applied to model data for surface magnetic fields calculated for a grounded, vertical electric source (VES). The conductivity structure is determined from comparing the measured migrated fields to calculated migrated fields for a yet to be determined conductivity structure. This comparison results in solving a Fredholm integral equation of the first kind for the conductivity structure. Solutions are obtained using the conjugate gradient method. The imaging method used here is similar to the EM holographic method reported earlier, except here the magnitudes, as well as the phases, of the extrapolated fields are preserved so that material properties can be determined.
A Dynamic Integration Method for Borderland Database using OSM data
NASA Astrophysics Data System (ADS)
Zhou, X.-G.; Jiang, Y.; Zhou, K.-X.; Zeng, L.
2013-11-01
Spatial data is the fundamental of borderland analysis of the geography, natural resources, demography, politics, economy, and culture. As the spatial region used in borderland researching usually covers several neighboring countries' borderland regions, the data is difficult to achieve by one research institution or government. VGI has been proven to be a very successful means of acquiring timely and detailed global spatial data at very low cost. Therefore VGI will be one reasonable source of borderland spatial data. OpenStreetMap (OSM) has been known as the most successful VGI resource. But OSM data model is far different from the traditional authoritative geographic information. Thus the OSM data needs to be converted to the scientist customized data model. With the real world changing fast, the converted data needs to be updated. Therefore, a dynamic integration method for borderland data is presented in this paper. In this method, a machine study mechanism is used to convert the OSM data model to the user data model; a method used to select the changed objects in the researching area over a given period from OSM whole world daily diff file is presented, the change-only information file with designed form is produced automatically. Based on the rules and algorithms mentioned above, we enabled the automatic (or semiautomatic) integration and updating of the borderland database by programming. The developed system was intensively tested.
Verification of E-Beam direct write integration into 28nm BEOL SRAM technology
NASA Astrophysics Data System (ADS)
Hohle, Christoph; Choi, Kang-Hoon; Gutsch, Manuela; Hanisch, Norbert; Seidel, Robert; Steidel, Katja; Thrun, Xaver; Werner, Thomas
2015-03-01
Electron beam direct write lithography (EBDW) potentially offers advantages for low-volume semiconductor manufacturing, rapid prototyping or design verification due to its high flexibility without the need of costly masks. However, the integration of this advanced patterning technology into complex CMOS manufacturing processes remains challenging. The low throughput of today's single e-Beam tools limits high volume manufacturing applications and maturity of parallel (multi) beam systems is still insufficient [1,2]. Additional concerns like transistor or material damage of underlying layers during exposure at high electron density or acceleration voltage have to be addressed for advanced technology nodes. In the past we successfully proved that potential degradation effects of high-k materials or ULK shrink can be neglected and were excluded by demonstrating integrated electrical results of 28nm node transistor and BEOL performance following 50kV electron beam dry exposure [3]. Here we will give an update on the integration of EBDW in the 300mm CMOS manufacturing processes of advanced integrated circuits at the 28nm SRAM node of GLOBALFOUNDRIES Dresden. The work is an update to what has been previously published [4]. E-beam patterning results of BEOL full chip metal and via layers with a dual damascene integration scheme using a 50kV VISTEC SB3050DW variable shaped electron beam direct writer at Fraunhofer IPMSCNT are demonstrated. For the patterning of the Metal layer a Mix & Match concept based on the sequence litho - etch -litho -etch (LELE) was developed and evaluated wherein several exposure fields were blanked out during the optical exposure. Etch results are shown and compared to the POR. Results are also shown on overlay performance and optimized e-Beam exposure time using most advanced data prep solutions and resist processes. The patterning results have been verified using fully integrated electrical measurement of metal lines and vias on wafer level. In
Series-parallel method of direct solar array regulation
NASA Technical Reports Server (NTRS)
Gooder, S. T.
1976-01-01
A 40 watt experimental solar array was directly regulated by shorting out appropriate combinations of series and parallel segments of a solar array. Regulation switches were employed to control the array at various set-point voltages between 25 and 40 volts. Regulation to within + or - 0.5 volt was obtained over a range of solar array temperatures and illumination levels as an active load was varied from open circuit to maximum available power. A fourfold reduction in regulation switch power dissipation was achieved with series-parallel regulation as compared to the usual series-only switching for direct solar array regulation.
ERIC Educational Resources Information Center
Boeije, Hennie; Slagt, Meike; van Wesel, Floryt
2013-01-01
In mixed methods research (MMR), integrating the quantitative and the qualitative components of a study is assumed to result in additional knowledge (or "yield"). This narrative review examines the extent to which MMR is used in the field of childhood trauma and provides directions for improving mixed methods studies in this field. A…
Compact integration factor methods for complex domains and adaptive mesh refinement.
Liu, Xinfeng; Nie, Qing
2010-08-10
Implicit integration factor (IIF) method, a class of efficient semi-implicit temporal scheme, was introduced recently for stiff reaction-diffusion equations. To reduce cost of IIF, compact implicit integration factor (cIIF) method was later developed for efficient storage and calculation of exponential matrices associated with the diffusion operators in two and three spatial dimensions for Cartesian coordinates with regular meshes. Unlike IIF, cIIF cannot be directly extended to other curvilinear coordinates, such as polar and spherical coordinate, due to the compact representation for the diffusion terms in cIIF. In this paper, we present a method to generalize cIIF for other curvilinear coordinates through examples of polar and spherical coordinates. The new cIIF method in polar and spherical coordinates has similar computational efficiency and stability properties as the cIIF in Cartesian coordinate. In addition, we present a method for integrating cIIF with adaptive mesh refinement (AMR) to take advantage of the excellent stability condition for cIIF. Because the second order cIIF is unconditionally stable, it allows large time steps for AMR, unlike a typical explicit temporal scheme whose time step is severely restricted by the smallest mesh size in the entire spatial domain. Finally, we apply those methods to simulating a cell signaling system described by a system of stiff reaction-diffusion equations in both two and three spatial dimensions using AMR, curvilinear and Cartesian coordinates. Excellent performance of the new methods is observed.
Compact integration factor methods for complex domains and adaptive mesh refinement
Liu, Xinfeng; Nie, Qing
2010-01-01
Implicit integration factor (IIF) method, a class of efficient semi-implicit temporal scheme, was introduced recently for stiff reaction-diffusion equations. To reduce cost of IIF, compact implicit integration factor (cIIF) method was later developed for efficient storage and calculation of exponential matrices associated with the diffusion operators in two and three spatial dimensions for Cartesian coordinates with regular meshes. Unlike IIF, cIIF cannot be directly extended to other curvilinear coordinates, such as polar and spherical coordinate, due to the compact representation for the diffusion terms in cIIF. In this paper, we present a method to generalize cIIF for other curvilinear coordinates through examples of polar and spherical coordinates. The new cIIF method in polar and spherical coordinates has similar computational efficiency and stability properties as the cIIF in Cartesian coordinate. In addition, we present a method for integrating cIIF with adaptive mesh refinement (AMR) to take advantage of the excellent stability condition for cIIF. Because the second order cIIF is unconditionally stable, it allows large time steps for AMR, unlike a typical explicit temporal scheme whose time step is severely restricted by the smallest mesh size in the entire spatial domain. Finally, we apply those methods to simulating a cell signaling system described by a system of stiff reaction-diffusion equations in both two and three spatial dimensions using AMR, curvilinear and Cartesian coordinates. Excellent performance of the new methods is observed. PMID:20543883
Systems and methods for bi-directional energy delivery with galvanic isolation
Kajouke, Lateef A.
2013-06-18
Systems and methods are provided for bi-directional energy delivery. A charging system comprises a first bi-directional conversion module, a second bi-directional conversion module, and an isolation module coupled between the first bi-directional conversion module and the second bi-directional conversion module. The isolation module provides galvanic isolation between the first bi-directional conversion module and the second bi-directional conversion module.
Method of and apparatus for testing the integrity of filters
Herman, R.L.
1985-05-07
A method of and apparatus are disclosed for testing the integrity of individual filters or filter stages of a multistage filtering system including a diffuser permanently mounted upstream and/or downstream of the filter stage to be tested for generating pressure differentials to create sufficient turbulence for uniformly dispersing trace agent particles within the airstream upstream and downstream of such filter stage. Samples of the particle concentration are taken upstream and downstream of the filter stage for comparison to determine the extent of particle leakage past the filter stage. 5 figs.
Method for deposition of a conductor in integrated circuits
Creighton, J. Randall; Dominguez, Frank; Johnson, A. Wayne; Omstead, Thomas R.
1997-01-01
A method is described for fabricating integrated semiconductor circuits and, more particularly, for the selective deposition of a conductor onto a substrate employing a chemical vapor deposition process. By way of example, tungsten can be selectively deposited onto a silicon substrate. At the onset of loss of selectivity of deposition of tungsten onto the silicon substrate, the deposition process is interrupted and unwanted tungsten which has deposited on a mask layer with the silicon substrate can be removed employing a halogen etchant. Thereafter, a plurality of deposition/etch back cycles can be carried out to achieve a predetermined thickness of tungsten.
Method for deposition of a conductor in integrated circuits
Creighton, J.R.; Dominguez, F.; Johnson, A.W.; Omstead, T.R.
1997-09-02
A method is described for fabricating integrated semiconductor circuits and, more particularly, for the selective deposition of a conductor onto a substrate employing a chemical vapor deposition process. By way of example, tungsten can be selectively deposited onto a silicon substrate. At the onset of loss of selectivity of deposition of tungsten onto the silicon substrate, the deposition process is interrupted and unwanted tungsten which has deposited on a mask layer with the silicon substrate can be removed employing a halogen etchant. Thereafter, a plurality of deposition/etch back cycles can be carried out to achieve a predetermined thickness of tungsten. 2 figs.
Investigation of system integration methods for bubble domain flight recorders
NASA Technical Reports Server (NTRS)
Chen, T. T.; Bohning, O. D.
1975-01-01
System integration methods for bubble domain flight records are investigated. Bubble memory module packaging and assembly, the control electronics design and construction, field coils, and permanent magnet bias structure design are studied. A small 60-k bit engineering model was built and tested to demonstrate the feasibility of the bubble recorder. Based on the various studies performed, a projection is made on a 50,000,000-bit prototype recorder. It is estimated that the recorder will occupy 190 cubic in., weigh 12 lb, and consume 12 w power when all of its four tracks are operated in parallel at 150 kHz data rate.
The biocommunication method: On the road to an integrative biology
Witzany, Guenther
2016-01-01
ABSTRACT Although molecular biology, genetics, and related special disciplines represent a large amount of empirical data, a practical method for the evaluation and overview of current knowledge is far from being realized. The main concepts and narratives in these fields have remained nearly the same for decades and the more recent empirical data concerning the role of noncoding RNAs and persistent viruses and their defectives do not fit into this scenario. A more innovative approach such as applied biocommunication theory could translate empirical data into a coherent perspective on the functions within and between biological organisms and arguably lead to a sustainable integrative biology. PMID:27195071
Methods of and apparatus for testing the integrity of filters
Herman, R.L.
1984-01-01
A method of and apparatus for testing the integrity of individual filters or filter stages of a multistage filtering system including a diffuser permanently mounted upstream and/or downstream of the filter stage to be tested for generating pressure differentials to create sufficient turbulence for uniformly dispersing trace agent particles within the airstram upstream and downstream of such filter stage. Samples of the particel concentration are taken upstream and downstream of the filter stage for comparison to determine the extent of particle leakage past the filter stage.
Method of and apparatus for testing the integrity of filters
Herman, Raymond L [Richland, WA
1985-01-01
A method of and apparatus for testing the integrity of individual filters or filter stages of a multistage filtering system including a diffuser permanently mounted upstream and/or downstream of the filter stage to be tested for generating pressure differentials to create sufficient turbulence for uniformly dispersing trace agent particles within the airstream upstream and downstream of such filter stage. Samples of the particle concentration are taken upstream and downstream of the filter stage for comparison to determine the extent of particle leakage past the filter stage.
Method of producing an integral resonator sensor and case
NASA Technical Reports Server (NTRS)
Shcheglov, Kirill V. (Inventor); Challoner, A. Dorian (Inventor); Hayworth, Ken J. (Inventor); Wiberg, Dean V. (Inventor); Yee, Karl Y. (Inventor)
2005-01-01
The present invention discloses an inertial sensor having an integral resonator. A typical sensor comprises a planar mechanical resonator for sensing motion of the inertial sensor and a case for housing the resonator. The resonator and a wall of the case are defined through an etching process. A typical method of producing the resonator includes etching a baseplate, bonding a wafer to the etched baseplate, through etching the wafer to form a planar mechanical resonator and the wall of the case and bonding an end cap wafer to the wall to complete the case.
NASA Astrophysics Data System (ADS)
Xu, Fujun; Yao, Lan; Zhao, Da; Jiang, Muwen; Qiu, Yipping
2013-10-01
A three-dimensionally integrated microstrip antenna (3DIMA) is a microstrip antenna woven into the three-dimensional woven composite for load bearing while functioning as an antenna. In this study, the effect of weaving direction of conductive yarns on electromagnetic performance of 3DIMAs are investigated by designing, simulating and experimental testing of two microstrip antennas with different weaving directions of conductive yarns: one has the conductive yarns along the antenna feeding direction (3DIMA-Exp1) and the other has the conductive yarns perpendicular the antenna feeding direction (3DIMA-Exp2). The measured voltage standing wave ratio (VSWR) of 3DIMA-Exp1 was 1.4 at the resonant frequencies of 1.39 GHz; while that of 3DIMA-Exp2 was 1.2 at the resonant frequencies of 1.35 GHz. In addition, the measured radiation pattern of the 3DIMA-Exp1 has smaller back lobe and higher gain value than those of the 3DIMA-Exp2. This result indicates that the waving direction of conductive yarns may have a significant impact on electromagnetic performance of textile structural antennas.
Sensitivity method for integrated structure/active control law design
NASA Technical Reports Server (NTRS)
Gilbert, Michael G.
1987-01-01
The development is described of an integrated structure/active control law design methodology for aeroelastic aircraft applications. A short motivating introduction to aeroservoelasticity is given along with the need for integrated structures/controls design algorithms. Three alternative approaches to development of an integrated design method are briefly discussed with regards to complexity, coordination and tradeoff strategies, and the nature of the resulting solutions. This leads to the formulation of the proposed approach which is based on the concepts of sensitivity of optimum solutions and multi-level decompositions. The concept of sensitivity of optimum is explained in more detail and compared with traditional sensitivity concepts of classical control theory. The analytical sensitivity expressions for the solution of the linear, quadratic cost, Gaussian (LQG) control problem are summarized in terms of the linear regulator solution and the Kalman Filter solution. Numerical results for a state space aeroelastic model of the DAST ARW-II vehicle are given, showing the changes in aircraft responses to variations of a structural parameter, in this case first wing bending natural frequency.
A direct mixed-body boundary element method for packed silencers.
Wu, T W; Cheng, C Y R; Zhang, P
2002-06-01
Bulk-reacting sound absorbing materials are often used in packed silencers to reduce broadband noise. A bulk-reacting material is characterized by a complex mean density and a complex speed of sound. These two material properties can be measured by the two-cavity method or calculated by empirical formulas. Modeling the entire silencer domain with a bulk-reacting lining will involve two different acoustic media, air and the bulk-reacting material. Traditionally, the interior silencer domain is divided into different zones and a multi-domain boundary element method (BEM) may be applied to solve the problem. However, defining different zones and matching the elements along each interface is tedious, especially when the zones are intricately connected. In this paper, a direct mixed-body boundary element method is used to model a packed silencer without subdividing it into different zones. This is achieved by summing up all the integral equations in different zones and then adding the hypersingular integral equations at interfaces. Several test cases, including a packed expansion chamber with and without an absorbing center bullet, and a parallel baffle silencer, are studied. Numerical results for the prediction of transmission loss (TL) are compared to experimental data.
A direct mixed-body boundary element method for packed silencers
NASA Astrophysics Data System (ADS)
Wu, T. W.; Cheng, C. Y. R.; Zhang, P.
2002-06-01
Bulk-reacting sound absorbing materials are often used in packed silencers to reduce broadband noise. A bulk-reacting material is characterized by a complex mean density and a complex speed of sound. These two material properties can be measured by the two-cavity method or calculated by empirical formulas. Modeling the entire silencer domain with a bulk-reacting lining will involve two different acoustic media, air and the bulk-reacting material. Traditionally, the interior silencer domain is divided into different zones and a multi-domain boundary element method (BEM) may be applied to solve the problem. However, defining different zones and matching the elements along each interface is tedious, especially when the zones are intricately connected. In this paper, a direct mixed-body boundary element method is used to model a packed silencer without subdividing it into different zones. This is achieved by summing up all the integral equations in different zones and then adding the hypersingular integral equations at interfaces. Several test cases, including a packed expansion chamber with and without an absorbing center bullet, and a parallel baffle silencer, are studied. Numerical results for the prediction of transmission loss (TL) are compared to experimental data. copyright 2002 Acoustical Society of America.
A Method for Increasing Elders' Use of Advance Directives.
ERIC Educational Resources Information Center
Luptak, Marilyn K.; Boult, Chad
1994-01-01
Studied effectiveness of intervention to help frail elders to record advance directives (ADs). In collaboration with physicians and lay volunteer, social worker provided information/counseling to elderly subjects, families, and proxies in series of visits to geriatric evaluation and management clinic. Seventy-one percent of subjects recorded ADs.…
Sleep Can Eliminate List-Method Directed Forgetting
ERIC Educational Resources Information Center
Abel, Magdalena; Bäuml, Karl-Heinz T.
2013-01-01
Recent work suggests a link between sleep and memory consolidation, indicating that sleep in comparison to wakefulness stabilizes memories. However, relatively little is known about how sleep affects forgetting. Here we examined whether sleep influences directed forgetting, the finding that people can intentionally forget obsolete memories when…
Navigational path integration by cortical neurons: origins in higher-order direction selectivity
Page, William K.; Sato, Nobuya; Froehler, Michael T.; Vaughn, William
2015-01-01
Navigation relies on the neural processing of sensory cues about observer self-movement and spatial location. Neurons in macaque dorsal medial superior temporal cortex (MSTd) respond to visual and vestibular self-movement cues, potentially contributing to navigation and orientation. We moved monkeys on circular paths around a room while recording the activity of MSTd neurons. MSTd neurons show a variety of sensitivities to the monkey's heading direction, circular path through the room, and place in the room. Changing visual cues alters the relative prevalence of those response properties. Disrupting the continuity of self-movement paths through the environment disrupts path selectivity in a manner linked to the time course of single neuron responses. We hypothesize that sensory cues interact with the spatial and temporal integrative properties of MSTd neurons to derive path selectivity for navigational path integration supporting spatial orientation. PMID:25589586
NASA Astrophysics Data System (ADS)
Mao, Xiao-Yu; Yao, Di-Bi; Zhao, Ling-Yun; Huang, Yi-Dong; Zhang, Wei; Peng, Jiang-De
2008-01-01
We propose an integrative biochemical sensor utilizing the dip in the transmission spectrum of a normal single-line defect photonic crystal (PC) waveguide, which has a contra-directional coupling with another PC waveguide. When the air holes in the PC slab are filled with a liquid analyte with different refractive indices, the dip has a wavelength shift By detecting the output power variation at a certain fixed wavelength, a sensitivity of 1.2 × 10-4 is feasible. This structure is easy for integration due to its plane waveguide structure and omissible pump source. In addition, high signal to noise ratio can be expected because signal transmits via a normal single-line defect PC waveguide instead of the PC hole area or analyte.
NASA Astrophysics Data System (ADS)
Liñares, Jesús; Barral, David; Nistal, María C.; Moreno, Vicente
2011-05-01
A quantum analysis of the generalized polarization properties of multimode single photon states is presented. It is based on the optical field-strength probability distributions in such a way that generalized polarization is understood as a significant confinement of the probability distribution along certain regions of the multidimensional optical field-strength space. The analysis is addressed to multimode integrated waveguiding devices, such as N × N integrated directional couplers, whose modes fulfil a spatial modal orthogonality relationship. For that purpose a definition of the quantum generalized polarization degree in a N-dimensional space, based on the concept of distance to an unpolarized N-dimensional Gaussian distribution, is proposed. The generalized polarization degree of pure and mixture multimode single photon states and also of some multi-photon states such as coherent and chaotic ones, is evaluated and analyzed.
Integration System of Head, Eye, and Retinal Position Signals for Perceptual Direction
NASA Astrophysics Data System (ADS)
Yamaguchi, Masashi; Kaneko, Hirohiko
2007-11-01
This study investigates the integration system of head (-to-trunk), eye (-to-head), and retinal position signals for hand pointing. In experiment 1, subjects changed their head and eye positions and pointed at a fixated visual stimulus by using an unseen pointer. In experiment 2, subjects fixated a visual stimulus and pointed at another visual stimulus. The results show that the head and eye position signals contributed linearly to perceptual direction (experiments 1 and 2), and that the coefficients of these signals decrease with peripheral vision and are smaller than the coefficient of the retinal position signal (experiment 2). These results collectively suggest that the integration algorithm of the position signals might be described by the linear summation equation and that the retinal position signal serves a more important role than the other position signals in the visual system.
The role of direct broadcasting satellites in the integrated communications environment
NASA Astrophysics Data System (ADS)
Rutkowski, A. M.
The global integration of information sources, telecommunication systems, and user terminals into a computer-controlled distributed communication network, known as the Integrated Services Digital Network (ISDN), will markedly affect the role of direct broadcasting satellites (DBS). DBS facilities will be increasingly used for the dissemination of non-video materials and will become a dominant means of electronic publishing. These facilities will also be used to selectively address information to dynamically definable classes of users, thus altering the very concept and definition of broadcasting. Finally, DBS will transform into multipoint distribution systems emanating from the ISDN. It is pointed out that although some of these developments wil not fully emerge for one or two decades, consideration should be given to the impact of the ISDN on society and its legal systems.
Integrated Data Collection Analysis (IDCA) Program - SSST Testing Methods
Sandstrom, Mary M.; Brown, Geoffrey W.; Preston, Daniel N.; Pollard, Colin J.; Warner, Kirstin F.; Remmers, Daniel L.; Sorensen, Daniel N.; Whinnery, LeRoy L.; Phillips, Jason J.; Shelley, Timothy J.; Reyes, Jose A.; Hsu, Peter C.; Reynolds, John G.
2013-03-25
The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the methods used for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis during the IDCA program. These methods changed throughout the Proficiency Test and the reasons for these changes are documented in this report. The most significant modifications in standard testing methods are: 1) including one specified sandpaper in impact testing among all the participants, 2) diversifying liquid test methods for selected participants, and 3) including sealed sample holders for thermal testing by at least one participant. This effort, funded by the Department of Homeland Security (DHS), is putting the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study will suggest new guidelines and methods and possibly establish the SSST testing accuracies needed to develop safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods wherever possible. The testing performers involved are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Indian Head Division, Naval Surface Warfare Center, (NSWC IHD), Sandia National Laboratories (SNL), and Air Force Research Laboratory (AFRL/RXQL). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to compare results when these testing variables cannot be made consistent.
Direct inversion methods for spectral amplitude modulation of femtosecond pulses.
Delgado-Aguillón, Jesús; Garduño-Mejía, Jesús; López-Téllez, Juan Manuel; Bruce, Neil C; Rosete-Aguilar, Martha; Román-Moreno, Carlos Jesús; Ortega-Martínez, Roberto
2014-04-01
In the present work, we applied an amplitude-spatial light modulator to shape the spectral amplitude of femtosecond pulses in a single step, without an iterative algorithm, by using an inversion method defined as the generalized retardance function. Additionally, we also present a single step method to shape the intensity profile defined as the influence matrix. Numerical and experimental results are presented for both methods.
Impact of beam smoothing method on direct drive target performance for the NIF
Rothenberg, J.E.; Weber, S.V.
1997-01-01
The impact of smoothing method on the performance of a direct drive target is modeled and examined in terms of its 1-mode spectrum. In particular, two classes of smoothing methods are compared, smoothing by spectral dispersion (SSD) and the induced spatial incoherence (ISI) method. It is found that SSD using sinusoidal phase modulation (FM) results in poor smoothing at low 1-modes and therefore inferior target performance at both peak velocity and ignition. This disparity is most notable if the effective imprinting integration time of the target is small. However, using SSD with more generalized phase modulation can result in smoothing at low l-modes which is identical to that obtained with ISI. For either smoothing method, the calculations indicate that at peak velocity the surface perturbations are about 100 times larger than that which leads to nonlinear hydrodynamics. Modeling of the hydrodynamic nonlinearity shows that saturation can reduce the amplified nonuniformities to the level required to achieve ignition for either smoothing method. The low l- mode behavior at ignition is found to be strongly dependent on the induced divergence of the smoothing method. For the NIF parameters the target performance asymptotes for smoothing divergence larger than {approximately}100 {mu}rad.
Walters, Daniel; Stringer, Simon; Rolls, Edmund
2013-01-01
The head direction cell system is capable of accurately updating its current representation of head direction in the absence of visual input. This is known as the path integration of head direction. An important question is how the head direction cell system learns to perform accurate path integration of head direction. In this paper we propose a model of velocity path integration of head direction in which the natural time delay of axonal transmission between a linked continuous attractor network and competitive network acts as a timing mechanism to facilitate the correct speed of path integration. The model effectively learns a "look-up" table for the correct speed of path integration. In simulation, we show that the model is able to successfully learn two different speeds of path integration across two different axonal conduction delays, and without the need to alter any other model parameters. An implication of this model is that, by learning look-up tables for each speed of path integration, the model should exhibit a degree of robustness to damage. In simulations, we show that the speed of path integration is not significantly affected by degrading the network through removing a proportion of the cells that signal rotational velocity.
An integrated-intensity method for emission spectrographic computer analysis
Thomas, Catharine P.
1975-01-01
An integrated-intensity method has been devised to improve the computer analysis of data by emission spectrography. The area of the intensity profile of a spectral line is approximated by a rectangle whose height is related to the intensity difference between the peak and background of the line and whose width is measured at a fixed transmittance below the apex of the line. The method is illustrated by the determination of strontium in the presence of greater than 10 percent calcium. The Sr 3380.711-A line, which is unaffected by calcium and which has a linear analytical curve extending from 100-3,000 ppm, has been used to determine strontium in 18 standard reference rocks covering a wide range of geologic materials. Both the accuracy and the precision of the determinations were well within the accepted range for a semiquantitative procedure.
The reduced basis method for the electric field integral equation
Fares, M.; Hesthaven, J.S.; Maday, Y.; Stamm, B.
2011-06-20
We introduce the reduced basis method (RBM) as an efficient tool for parametrized scattering problems in computational electromagnetics for problems where field solutions are computed using a standard Boundary Element Method (BEM) for the parametrized electric field integral equation (EFIE). This combination enables an algorithmic cooperation which results in a two step procedure. The first step consists of a computationally intense assembling of the reduced basis, that needs to be effected only once. In the second step, we compute output functionals of the solution, such as the Radar Cross Section (RCS), independently of the dimension of the discretization space, for many different parameter values in a many-query context at very little cost. Parameters include the wavenumber, the angle of the incident plane wave and its polarization.
Method for direct conversion of gaseous hydrocarbons to liquids
Kong, Peter C.; Lessing, Paul A.
2006-03-07
A chemical reactor for direct conversion of hydrocarbons includes a dielectric barrier discharge plasma cell and a solid oxide electrochemical cell in fluid communication therewith. The discharge plasma cell comprises a pair of electrodes separated by a dielectric material and passageway therebetween. The electrochemical cell comprises a mixed-conducting solid oxide electrolyte membrane tube positioned between a porous cathode and a porous anode, and a gas inlet tube for feeding oxygen containing gas to the porous cathode. An inlet is provided for feeding hydrocarbons to the passageway of the discharge plasma cell, and an outlet is provided for discharging reaction products from the reactor. A packed bed catalyst may optionally be used in the reactor to increase efficiency of conversion. The reactor can be modified to allow use of a light source for directing ultraviolet light into the discharge plasma cell and the electrochemical cell.
Method of forming grooves in the [011] crystalline direction
NASA Technical Reports Server (NTRS)
Marinelli, Donald Paul (Inventor)
1977-01-01
An A-B etchant is applied to a (100) surface of a body of semiconductor material, a portion of which along the (100) surface of the body is either gallium arsenide or gallium aluminum arsenide. The etchant is applied for at least 15 seconds at a temperature of approximately 80.degree. C. The A-B etchant is a solution by weight percent of 47.5%, water, 0.2% silver nitrate, 23.8% chromium trioxide and 28.5% of a 48% aqueous solution of hydrofluoric acid. As a result of the application of the A-B etchant a pattern of elongated etch pits form having their longitudinal axes along the [011] crystalline direction. Grooves are formed in the body at a surface opposite the (100) surface on which was applied the etchant. The grooves are formed along the [011] crystalline direction by aligning the longitudinal axes of the grooves with the longitudinal axes of the etch pits.
The Flux-integral Method for Multidimensional Convection and Diffusion
NASA Technical Reports Server (NTRS)
Leonard, B. P.; Macvean, M. K.; Lock, A. P.
1994-01-01
The flux-integral method is a procedure for constructing an explicit, single-step, forward-in-time, conservative, control volume update of the unsteady, multidimensional convection-diffusion equation. The convective plus diffusive flux at each face of a control-volume cell is estimated by integrating the transported variable and its face-normal derivative over the volume swept out by the convecting velocity field. This yields a unique description of the fluxes, whereas other conservative methods rely on nonunique, arbitrary pseudoflux-difference splitting procedures. The accuracy of the resulting scheme depends on the form of the subcell interpolation assumed, given cell-average data. Cellwise constant behavior results in a (very artificially diffusive) first-order convection scheme. Second-order convection-diffusion schemes correspond to cellwise linear (or bilinear) subcell interpolation. Cellwise quadratic subcell interpolants generate a highly accurate convection-diffusion scheme with excellent phase accuracy. Under constant-coefficient conditions, this is a uniformly third-order polynomial interpolation algorithm (UTOPIA).
Xu, W; Zhu, Z H; Liu, K; Zhang, J F; Yuan, X D; Lu, Q S; Qin, S Q
2015-04-01
We propose and numerically analyze a mid-infrared electrically controllable plasmonic waveguide directional coupler that is composed of two parallel identical straight dielectric loaded graphene plasmonic waveguide and S-shaped waveguide bends. By varying the Fermi energy level of the graphene sheet, the maximum power coupled from the input waveguide to the cross-waveguide and the corresponding coupling length could be effectively tuned. Under different Fermi energy level, this directional coupler could serve as an electrically controlled optical switch or a 3-dB splitter around the wavelength of 10.5 μm. Moreover, the size of the entire device is really in sub-wavelength scale making it very facilitative for high density integration.
Multisensor satellite data integration for sea surface wind speed and direction determination
NASA Technical Reports Server (NTRS)
Glackin, D. L.; Pihos, G. G.; Wheelock, S. L.
1984-01-01
Techniques to integrate meteorological data from various satellite sensors to yield a global measure of sea surface wind speed and direction for input to the Navy's operational weather forecast models were investigated. The sensors were launched or will be launched, specifically the GOES visible and infrared imaging sensor, the Nimbus-7 SMMR, and the DMSP SSM/I instrument. An algorithm for the extrapolation to the sea surface of wind directions as derived from successive GOES cloud images was developed. This wind veering algorithm is relatively simple, accounts for the major physical variables, and seems to represent the best solution that can be found with existing data. An algorithm for the interpolation of the scattered observed data to a common geographical grid was implemented. The algorithm is based on a combination of inverse distance weighting and trend surface fitting, and is suited to combing wind data from disparate sources.
Haner, D A; McGuckin, B T; Menzies, R T; Bruegge, C J; Duval, V
1998-06-20
The directional-hemispherical reflectance is obtained for Spectralon, the material chosen for onboard radiometric calibration of the multiangle imaging spectroradiometer, at laser wavelengths of 442, 632.8, and 859.9 nm. With p- and s-polarized incident light and for an angle of incidence of 45 degrees , the bidirectional reflectance distribution function was measured over a polar angle range of 1-85 degrees and a range of azimuthal angles of 0-180 degrees in 10 degrees increments. The resultant directional-hemispherical reflectance is found by integration to be 1.00 ? 0.01 at 442 nm, 0.953 ? 0.01 at 632.8 nm, and 0.956 ? 0.01 at 859.9 nm. The experimental methodology and the data analysis are presented together with a full discussion of the primary experimental errors.
Nanomachines: methods to induce a directed motion at nanoscale.
Popov, V L
2003-08-01
The motion of bodies in a periodic potential with weak damping is discussed. A spontaneous directed motion of particles is shown to be possible in the presence of external periodic forces at a velocity unambiguously defined by the frequency of the periodic action and the spatial period of the potential. The principle of inducing the directed motion at a precisely controlled velocity can be used to develop (i) means of handling individual molecules or molecular clusters on crystalline surfaces; (ii) "nanomachines"-objects capable of spontaneous motion not only in the absence of an external force but also under the action of a force opposite to the direction of motion (and thereby capable of carrying other particles); (iii) drives providing precisely controlled velocity of motion; (iv) controllable tribological systems constructed by profiling friction surfaces in a specified manner and applying an ultrasonic excitation. The dependence of the average system velocity on the average applied force is shown to have plateaus of constant velocity at zero velocity and a set of equidistant discrete velocities in the presence of periodic external perturbations. The problem of developing fully controlled nanomachines can be formulated as the problem of controlling the width and position of the plateaus.
A new method for the evaluation of the direct effect of the ship traffic on PAHs
NASA Astrophysics Data System (ADS)
Gregoris, Elena; De Pieri, Silvia; Barbaro, Elena; Piazza, Rossano; Gambaro, Andrea; Contini, Daniele
2015-04-01
Emissions of exhaust gases and particles from ships can affect significantly the chemical composition of the atmosphere, local and regional air quality and climate. These emissions might have harmful effects on human health, since Mediterranean harbors are often located near or within the cities. Moreover ships and harbours emissions are currently increasing, due to the grow of tourism and trade, further amplifying this issue. International legislation and local agreements are mainly based on the use of low-sulphur fuel content, but also other chemicals, such as polycyclic aromatic hydrocarbons (PAHs), play an important role. Because of their low reactivity PAHs can persist in the environment for a long time; moreover they bioaccumulate, causing adverse effect on human health, such as reproductive and immune effects, developmental anomalies and cancer. This work is linked to the POSEIDON project (POllution monitoring of Ship Emission: an IntegrateD approach fOr harbor of the Adriatic basiN), that aims to quantify the atmospheric pollution generated by ship traffic and harbor activities in four port-cities of the Adriatic Sea (Brindisi, Venice, Rijeka, Patras). Here, a new method for the evaluation of the direct effect of ship traffic and harbour activities on polycyclic aromatic hydrocarbons is presented. In this method two high-volume samplers are operating: one of them collecting air from all directions; the other one is programmed to activate only when the wind is blowing from a specific sector (the harbour area). From the compared results, information about the effect of the harbour on the global PAHs concentration can be obtained. The method was applied in Venice in two summer sampling campaigns, in 2009 and 2012.
Directions for Mind, Brain, and Education: Methods, Models, and Morality
ERIC Educational Resources Information Center
Stein, Zachary; Fischer, Kurt W.
2011-01-01
In this article we frame a set of important issues in the emerging field of Mind, Brain, and Education in terms of three broad headings: methods, models, and morality. Under the heading of methods we suggest that the need for synthesis across scientific and practical disciplines entails the pursuit of usable knowledge via a catalytic symbiosis…
A method for increasing elders' use of advance directives.
Luptak, M K; Boult, C
1994-06-01
Most published studies report that few elderly people have recorded advance directives (AD). We studied the effectiveness of an interdisciplinary intervention designed to help ambulatory frail elders to record AD. In collaboration with physicians and a trained lay volunteer, a social worker provided information and counseling to the elderly subjects, to their families, and to their proxies in a series of visits to a geriatric evaluation and management (GEM) clinic. Seventy-one percent of the subjects recorded AD. Of these, 96% named a proxy, and 83% recorded specific treatment preferences.
Direct integration of metal oxide nanowires into an effective gas sensing device.
Vomiero, Alberto; Ponzoni, Andrea; Comini, Elisabetta; Ferroni, Matteo; Faglia, Guido; Sberveglieri, Giorgio
2010-04-01
A simple and large-area scalable methodology has been set up for direct integration of metal oxide nanowire bundles into a functional device for gas sensing. It is based on sequential application of two consolidated techniques, namely high temperature vapour transport and condensation for fabrication of metal oxide nanowires, and wet etching of a sacrificial layer. The alumina substrate patterned with a silicon dioxide sacrificial layer does not influence the growth of nanowires and remains unaltered under the high temperature process. The sacrificial layer is finally removed under hydrofluoric acid, the metal oxide nanowires do not suffer modifications and a clean substrate surface can be obtained for deposition of stable metal contacts. The methodology was proven effective for application in a gas sensor device. Electrical measurements indicate that a slightly rectifying Schottky junction is present at low temperatures (up to T = 150 degrees C) between nanowires and platinum electrodes, which vanishes as the temperature increases and under high voltage (bias voltage above approximately 3 V). The results foresee the possibility of growth and integration of nanowire bundles directly into devices, overcoming the need for expensive and time-consuming nanomanipulation techniques.
McCammon, Richard B.; Ramani, Raja V.; Mozumdar, Bijoy K.; Samaddar, Arun B.
1994-01-01
Overcoming future difficulties in searching for ore deposits deeper in the earth's crust will require closer attention to the collection and analysis of more diverse types of data and to more efficient use of current computer technologies. Computer technologies of greatest interest include methods of storage and retrieval of resource information, methods for integrating geologic, geochemical, and geophysical data, and the introduction of advanced computer technologies such as expert systems, multivariate techniques, and neural networks. Much experience has been gained in the past few years in applying these technologies. More experience is needed if they are to be implemented for everyday use in future assessments and exploration.
An Integration Factor Method for Stochastic and Stiff Reaction-Diffusion Systems
Ta, Catherine; Wang, Dongyong; Nie, Qing
2015-01-01
Stochastic effects are often present in the biochemical systems involving reactions and diffusions. When the reactions are stiff, existing numerical methods for stochastic reaction diffusion equations require either very small time steps for any explicit schemes or solving large nonlinear systems at each time step for the implicit schemes. Here we present a class of semi-implicit integration factor methods that treat the diffusion term exactly and reaction implicitly for a system of stochastic reaction-diffusion equations. Our linear stability analysis shows the advantage of such methods for both small and large amplitudes of noise. Direct use of the method to solving several linear and nonlinear stochastic reaction-diffusion equations demonstrates good accuracy, efficiency, and stability properties. This new class of methods, which are easy to implement, will have broader applications in solving stochastic reaction-diffusion equations arising from models in biology and physical sciences. PMID:25983341
An integration factor method for stochastic and stiff reaction–diffusion systems
Ta, Catherine; Wang, Dongyong; Nie, Qing
2015-08-15
Stochastic effects are often present in the biochemical systems involving reactions and diffusions. When the reactions are stiff, existing numerical methods for stochastic reaction diffusion equations require either very small time steps for any explicit schemes or solving large nonlinear systems at each time step for the implicit schemes. Here we present a class of semi-implicit integration factor methods that treat the diffusion term exactly and reaction implicitly for a system of stochastic reaction–diffusion equations. Our linear stability analysis shows the advantage of such methods for both small and large amplitudes of noise. Direct use of the method to solving several linear and nonlinear stochastic reaction–diffusion equations demonstrates good accuracy, efficiency, and stability properties. This new class of methods, which are easy to implement, will have broader applications in solving stochastic reaction–diffusion equations arising from models in biology and physical sciences.
An integration factor method for stochastic and stiff reaction-diffusion systems
NASA Astrophysics Data System (ADS)
Ta, Catherine; Wang, Dongyong; Nie, Qing
2015-08-01
Stochastic effects are often present in the biochemical systems involving reactions and diffusions. When the reactions are stiff, existing numerical methods for stochastic reaction diffusion equations require either very small time steps for any explicit schemes or solving large nonlinear systems at each time step for the implicit schemes. Here we present a class of semi-implicit integration factor methods that treat the diffusion term exactly and reaction implicitly for a system of stochastic reaction-diffusion equations. Our linear stability analysis shows the advantage of such methods for both small and large amplitudes of noise. Direct use of the method to solving several linear and nonlinear stochastic reaction-diffusion equations demonstrates good accuracy, efficiency, and stability properties. This new class of methods, which are easy to implement, will have broader applications in solving stochastic reaction-diffusion equations arising from models in biology and physical sciences.
Fully Integrated Microfluidic Device for Direct Sample-to-Answer Genetic Analysis
NASA Astrophysics Data System (ADS)
Liu, Robin H.; Grodzinski, Piotr
Integration of microfluidics technology with DNA microarrays enables building complete sample-to-answer systems that are useful in many applications such as clinic diagnostics. In this chapter, a fully integrated microfluidic device [1] that consists of microfluidic mixers, valves, pumps, channels, chambers, heaters, and a DNA microarray sensor to perform DNA analysis of complex biological sample solutions is present. This device can perform on-chip sample preparation (including magnetic bead-based cell capture, cell preconcentration and purification, and cell lysis) of complex biological sample solutions (such as whole blood), polymerase chain reaction, DNA hybridization, and electrochemical detection. A few novel microfluidic techniques were developed and employed. A micromix-ing technique based on a cavitation microstreaming principle was implemented to enhance target cell capture from whole blood samples using immunomagnetic beads. This technique was also employed to accelerate DNA hybridization reaction. Thermally actuated paraffin-based microvalves were developed to regulate flows. Electrochemical pumps and thermopneumatic pumps were integrated on the chip to provide pumping of liquid solutions. The device is completely self-contained: no external pressure sources, fluid storage, mechanical pumps, or valves are necessary for fluid manipulation, thus eliminating possible sample contamination and simplifying device operation. Pathogenic bacteria detection from ~mL whole blood samples and single-nucleotide polymorphism analysis directly from diluted blood were demonstrated. The device provides a cost-effective solution to direct sample-to-answer genetic analysis, and thus has a potential impact in the fields of point-of-care genetic analysis, environmental testing, and biological warfare agent detection.
Cu-Cu direct bonding achieved by surface method at room temperature
Utsumi, Jun; Ichiyanagi, Yuko
2014-02-20
The metal bonding is a key technology in the processes for the microelectromechanical systems (MEMS) devices and the semiconductor devices to improve functionality and higher density integration. Strong adhesion between surfaces at the atomic level is crucial; however, it is difficult to achieve close bonding in such a system. Cu films were deposited on Si substrates by vacuum deposition, and then, two Cu films were bonded directly by means of surface activated bonding (SAB) at room temperature. The two Cu films, with the surface roughness Ra about 1.3nm, were bonded by using SAB at room temperature, however, the bonding strength was very weak in this method. In order to improve the bonding strength between the Cu films, samples were annealed at low temperatures, between 323 and 473 K, in air. As the result, the Cu-Cu bonding strength was 10 times higher than that of the original samples without annealing.
Direct mounted photovoltaic device with improved adhesion and method thereof
Boven, Michelle L; Keenihan, James R; Lickly, Stan; Brown, Jr., Claude; Cleereman, Robert J; Plum, Timothy C
2014-12-23
The present invention is premised upon a photovoltaic device suitable for directly mounting on a structure. The device includes an active portion including a photovoltaic cell assembly having a top surface portion that allows transmission of light energy to a photoactive portion of the photovoltaic device for conversion into electrical energy and a bottom surface having a bottom bonding zone; and an inactive portion immediately adjacent to and connected to the active portion, the inactive portion having a region for receiving a fastener to connect the device to the structure and having on a top surface, a top bonding zone; wherein one of the top and bottom bonding zones comprises a first bonding element and the other comprises a second bonding element, the second bonding element designed to interact with the first bonding element on a vertically overlapped adjacent photovoltaic device to bond the device to such adjacent device or to the structure.
Forgetting unwanted memories: directed forgetting and thought suppression methods.
Geraerts, Elke; McNally, Richard J
2008-03-01
Experimental psychopathologists have tested hypotheses regarding mechanisms that ought to be operative if victims possess skills for forgetting material related to trauma. In this article, we review research on directed forgetting and thought suppression paradigms, concentrating on laboratory studies involving attempts by individuals reporting trauma histories to forget emotionally negative material. Most studies have shown that trauma survivors, especially those with post-traumatic stress disorder, are characterized by a breakdown in the ability to forget disturbing material. Studies on individuals reporting repressed or recovered memories of trauma have not confirmed predictions regarding heightened forgetting skills for trauma-related words. However, recent research on suppressing disturbing autobiographical memories suggests that people who report spontaneously recalling childhood abuse outside of psychotherapy may, indeed, possess skills for not thinking about disturbing material.
Ducted combustion chamber for direct injection engines and method
Mueller, Charles
2015-03-03
An internal combustion engine includes an engine block having a cylinder bore and a cylinder head having a flame deck surface disposed at one end of the cylinder bore. A piston connected to a rotatable crankshaft and configured to reciprocate within the cylinder bore has a piston crown portion facing the flame deck surface such that a combustion chamber is defined within the cylinder bore and between the piston crown and the flame deck surface. A fuel injector having a nozzle tip disposed in fluid communication with the combustion chamber has at least one nozzle opening configured to inject a fuel jet into the combustion chamber along a fuel jet centerline. At least one duct defined in the combustion chamber between the piston crown and the flame deck surface has a generally rectangular cross section and extends in a radial direction relative to the cylinder bore substantially along the fuel jet centerline.
Divergence of Scientific Heuristic Method and Direct Algebraic Instruction
ERIC Educational Resources Information Center
Calucag, Lina S.
2016-01-01
This is an experimental study, made used of the non-randomized experimental and control groups, pretest-posttest designs. The experimental and control groups were two separate intact classes in Algebra. For a period of twelve sessions, the experimental group was subjected to the scientific heuristic method, but the control group instead was given…
Reverse and direct methods for solving the characteristic equation
NASA Astrophysics Data System (ADS)
Lozhkin, Alexander; Bozek, Pavol; Lyalin, Vadim; Tarasov, Vladimir; Tothova, Maria; Sultanov, Ravil
2016-06-01
Fundamentals of information-linguistic interpretation of the geometry presented shortly. The method of solving the characteristic equation based on Euler's formula is described. The separation of the characteristic equation for several disassembled for Jordan curves. Applications of the theory for problems of mechatronics outlined briefly.
Job Search as Goal-Directed Behavior: Objectives and Methods
ERIC Educational Resources Information Center
Van Hoye, Greet; Saks, Alan M.
2008-01-01
This study investigated the relationship between job search objectives (finding a new job/turnover, staying aware of job alternatives, developing a professional network, and obtaining leverage against an employer) and job search methods (looking at job ads, visiting job sites, networking, contacting employment agencies, contacting employers, and…
"Whole" Ballet Education: Exploring Direct and Indirect Teaching Methods
ERIC Educational Resources Information Center
Choi, Euichang; Kim, Na-ye
2015-01-01
The purpose of this study was to explore teaching methods for whole ballet in Korean ballet education. This study built upon a first phase of research that identified the educational content of "whole" ballet. Four dimensions were identified as the educational content: "physical," "cognitive," "emotional"…
Apparatus and method for defect testing of integrated circuits
Cole, Jr., Edward I.; Soden, Jerry M.
2000-01-01
An apparatus and method for defect and failure-mechanism testing of integrated circuits (ICs) is disclosed. The apparatus provides an operating voltage, V.sub.DD, to an IC under test and measures a transient voltage component, V.sub.DDT, signal that is produced in response to switching transients that occur as test vectors are provided as inputs to the IC. The amplitude or time delay of the V.sub.DDT signal can be used to distinguish between defective and defect-free (i.e. known good) ICs. The V.sub.DDT signal is measured with a transient digitizer, a digital oscilloscope, or with an IC tester that is also used to input the test vectors to the IC. The present invention has applications for IC process development, for the testing of ICs during manufacture, and for qualifying ICs for reliability.
Apparatus and method for defect testing of integrated circuits
Cole, E.I. Jr.; Soden, J.M.
2000-02-29
An apparatus and method for defect and failure-mechanism testing of integrated circuits (ICs) is disclosed. The apparatus provides an operating voltage, V(DD), to an IC under test and measures a transient voltage component, V(DDT), signal that is produced in response to switching transients that occur as test vectors are provided as inputs to the IC. The amplitude or time delay of the V(DDT) signal can be used to distinguish between defective and defect-free (i.e. known good) ICs. The V(DDT) signal is measured with a transient digitizer, a digital oscilloscope, or with an IC tester that is also used to input the test vectors to the IC. The present invention has applications for IC process development, for the testing of ICs during manufacture, and for qualifying ICs for reliability.
NASA Astrophysics Data System (ADS)
Deka, Bidyut; Dutta, Aradhana; Sahu, Partha P.
2013-11-01
The miniaturization of photonic components in integrated optic waveguide devices to microscale platform has attracted enormous attention from the researchers and entrepreneurs. In this paper, we present and report a comparative study of photonic integrated planar waveguide based couplers using a mathematical model based on sinusoidal mode simple effective index method (SEIM). The basic photonic integrated components such as directional coupler (DC), two mode interference (TMI) coupler and multimode interference (MMI) coupler have been designed and fabricated using the versatile SiON waveguide technology (SiON as the waveguide core material using silica waveguide). The experimental results have been compared with the SEIM based theoretical results and further verified with the commercially available software tool based on beam propagation method (BPM). With a focus towards device compactness, particular emphasis is placed on device geometry in an endeavour to achieve the same. In this direction, the theoretical and experimental results obtained have been compared with tooth shaped grating assisted geometry for these photonic components. It is found that the grating assisted structures have the beat length ~0.5 times lower than that of the conventional geometry. Further it is seen that the beat length of TMI coupler is smaller compared to the DC and MMI coupler.
Attachment method for stacked integrated circuit (IC) chips
Bernhardt, A.F.; Malba, V.
1999-08-03
An attachment method for stacked integrated circuit (IC) chips is disclosed. The method involves connecting stacked chips, such as DRAM memory chips, to each other and/or to a circuit board. Pads on the individual chips are rerouted to form pads on the side of the chip, after which the chips are stacked on top of each other whereby desired interconnections to other chips or a circuit board can be accomplished via the side-located pads. The pads on the side of a chip are connected to metal lines on a flexible plastic tape (flex) by anisotropically conductive adhesive (ACA). Metal lines on the flex are likewise connected to other pads on chips and/or to pads on a circuit board. In the case of a stack of DRAM chips, pads to corresponding address lines on the various chips may be connected to the same metal line on the flex to form an address bus. This method has the advantage of reducing the number of connections required to be made to the circuit board due to bussing; the flex can accommodate dimensional variation in the alignment of chips in the stack; bonding of the ACA is accomplished at low temperature and is otherwise simpler and less expensive than solder bonding; chips can be bonded to the ACA all at once if the sides of the chips are substantially coplanar, as in the case for stacks of identical chips, such as DRAM. 12 figs.
Attachment method for stacked integrated circuit (IC) chips
Bernhardt, Anthony F.; Malba, Vincent
1999-01-01
An attachment method for stacked integrated circuit (IC) chips. The method involves connecting stacked chips, such as DRAM memory chips, to each other and/or to a circuit board. Pads on the individual chips are rerouted to form pads on the side of the chip, after which the chips are stacked on top of each other whereby desired interconnections to other chips or a circuit board can be accomplished via the side-located pads. The pads on the side of a chip are connected to metal lines on a flexible plastic tape (flex) by anisotropically conductive adhesive (ACA). Metal lines on the flex are likewise connected to other pads on chips and/or to pads on a circuit board. In the case of a stack of DRAM chips, pads to corresponding address lines on the various chips may be connected to the same metal line on the flex to form an address bus. This method has the advantage of reducing the number of connections required to be made to the circuit board due to bussing; the flex can accommodate dimensional variation in the alignment of chips in the stack; bonding of the ACA is accomplished at low temperature and is otherwise simpler and less expensive than solder bonding; chips can be bonded to the ACA all at once if the sides of the chips are substantially coplanar, as in the case for stacks of identical chips, such as DRAM.
Marx, Hans; Mecklenbräuker, Astrid; Gasser, Brigitte; Sauer, Michael; Mattanovich, Diethard
2009-12-01
The yeast Pichia pastoris is a widely used host organism for heterologous protein production. One of the basic steps for strain improvement is to ensure a sufficient level of transcription of the heterologous gene, based on promoter strength and gene copy number. To date, high-copy-number integrants of P. pastoris are achievable only by screening of random events or by cloning of gene concatemers. Methods for rapid and reliable multicopy integration of the expression cassette are therefore desirable. Here we present such a method based on vector integration into the rDNA locus and post-transformational vector amplification by repeated selection on increased antibiotic concentrations. Data are presented for two exemplary products: human serum albumin, which is secreted into the supernatant, and human superoxide dismutase, which is accumulated in the cytoplasm of the cells. The striking picture evolving is that intracellular protein production is tightly correlated with gene copy number, while use of the secretory pathway introduces a high clonal variability and the correlation with gene copy number is valid only for low gene copy numbers. PMID:19799640
Dynactin integrity depends upon direct binding of dynamitin to Arp1
Cheong, Frances Ka Yan; Feng, Lijuan; Sarkeshik, Ali; Yates, John R.; Schroer, Trina A.
2014-01-01
Dynactin is a multiprotein complex that works with cytoplasmic dynein and other motors to support a wide range of cell functions. It serves as an adaptor that binds both dynein and cargoes and enhances single-motor processivity. The dynactin subunit dynamitin (also known as p50) is believed to be integral to dynactin structure because free dynamitin displaces the dynein-binding p150Glued subunit from the cargo-binding Arp1 filament. We show here that the intrinsically disordered dynamitin N-terminus binds to Arp1 directly. When expressed in cells, dynamitin amino acids (AA) 1–87 causes complete release of endogenous dynamitin, p150, and p24 from dynactin, leaving behind Arp1 filaments carrying the remaining dynactin subunits (CapZ, p62, Arp11, p27, and p25). Tandem-affinity purification–tagged dynamitin AA 1–87 binds the Arp filament specifically, and binding studies with purified native Arp1 reveal that this fragment binds Arp1 directly. Neither CapZ nor the p27/p25 dimer contributes to interactions between dynamitin and the Arp filament. This work demonstrates for the first time that Arp1 can directly bind any protein besides another Arp and provides important new insight into the underpinnings of dynactin structure. PMID:24829381
Silicon electro-optic modulator based on an ITO-integrated tunable directional coupler
NASA Astrophysics Data System (ADS)
Kim, Jin-Soo; Kim, Jin Tae
2016-02-01
Indium-tin-oxide (ITO) has attracted great attention because of its electrically-induced epsilon-near-zero (ENZ) characteristics, which has allowed us to develop electro-absorption optical modulators. As an extended application of ITO in a silicon optical modulator, we propose a silicon electro-optic modulator based on an ITO-integrated tunable directional coupler. An ITO block placed at the center of the two-core silicon directional coupler plays a key role in attenuating the optical power of the guided modes. Strong confinement of the optical field at the ENZ layer of ITO with the nonzero imaginary part of ITO’s permittivity let the guiding light experience high absorption as it propagates along the directional coupler. Numerical simulations reveal that the highest modulation depth of 5 dB is achievable at the ENZ region of ITO at a 1.55 μm wavelength. We can modulate the optical signals on an entire C-band ranging from a 1.530 to 1.565 μm wavelength with an on/off extinction ratio of larger than 4.6 dB.
Temperature measurement methods during direct heat arterial tissue fusion.
Cezo, James D; Kramer, Eric; Taylor, Kenneth D; Ferguson, Virginia; Rentschler, Mark E
2013-09-01
Fusion of biological tissues through direct and indirect heating is a growing area of medical research, yet there are still major gaps in understanding this procedure. Several companies have developed devices which fuse blood vessels, but little is known about the tissue's response to the stimuli. The need for accurate measurements of tissue behavior during tissue fusion is essential for the continued development and improvement of energy delivery devices. An experimental study was performed to measure the temperatures experienced during tissue fusion and the resulting burst pressure of the fused arteries. An array of thermocouples was placed in the lumen of a porcine splenic artery segment and sealed using a ConMed Altrus thermal fusion device. The temperatures within the tissue, in the device, and at the tissue-device interface were recorded. These measurements were then analyzed to calculate the temperature profile in the lumen of the artery. The temperature in the artery at the site of tissue fusion was measured to range from 142 to 163 °C using the ConMed Altrus. The corresponding burst pressure for arteries fused at this temperature was measured as 416 ± 79 mmHg. This study represents the first known experimental measurement of temperature at the site of vessel sealing found in the literature.
Trigonometrically fitted two step hybrid method for the numerical integration of second order IVPs
NASA Astrophysics Data System (ADS)
Monovasilis, Th.; Kalogiratou, Z.; Simos, T. E.
2016-06-01
In this work we consider the numerical integration of second order ODEs where the first derivative is missing. We construct trigonometrically fitted two step hybrid methods. We apply the new methods on the numerical integration of several test problems.
Hubbell rectangular source integral calculation using a fast Chebyshev wavelets method.
Manai, K; Belkadhi, K
2016-07-01
An integration method based on Chebyshev wavelets is presented and used to calculate the Hubbell rectangular source integral. A study of the convergence and the accuracy of the method was carried out by comparing it to previous studies. PMID:27152913
Bi-Directional Evolutionary Topology Optimization Using Element Replaceable Method
NASA Astrophysics Data System (ADS)
Zhu, J. H.; Zhang, W. H.; Qiu, K. P.
2007-06-01
In the present paper, design problems of maximizing the structural stiffness or natural frequency are considered subject to the material volume constraint. A new element replaceable method (ERPM) is proposed for evolutionary topology optimization of structures. Compared with existing versions of evolutionary structural optimization methods, contributions are twofold. On the one hand, a new automatic element deletion/growth procedure is established. The deletion of a finite element means that a solid element is replaced with an orthotropic cellular microstructure (OCM) element. The growth of an element means that an OCM element is replaced with a solid element of full materials. In fact, both operations are interchangeable depending upon how the value of element sensitivity is with respect to the objective function. The OCM design strategy is beneficial in preventing artificial modes for dynamic problems. Besides, the iteration validity is greatly improved with the introduction of a check position (CP) technique. On the other hand, a new checkerboard control algorithm is proposed to work together with the above procedure. After the identification of local checkerboards and detailed structures over the entire design domain, the algorithm will fill or delete elements depending upon the prescribed threshold of sensitivity values. Numerical results show that the ERPM is efficient and a clear and valuable material pattern can be achieved for both static and dynamic problems.
Atomic Calculations with a One-Parameter, Single Integral Method.
ERIC Educational Resources Information Center
Baretty, Reinaldo; Garcia, Carmelo
1989-01-01
Presents an energy function E(p) containing a single integral and one variational parameter, alpha. Represents all two-electron integrals within the local density approximation as a single integral. Identifies this as a simple treatment for use in an introductory quantum mechanics course. (MVL)
Herraez-Hernandez, Elsa; Alvarez-Perez, Martina; Navarro-Bustos, Gloria; Esquivias, Javier; Alonso, Sonia; Aneiros-Fernandez, Jose; Lacruz-Pelea, Cesar; Sanchez-Aguera, Magdalena; Santamaria, Javier Saenz; de Antonio, Jesus Chacon; Rodriguez-Peralto, Jose Luis
2013-10-01
HPV Direct Flow CHIP is a newly developed test for identifying 18 high-risk and 18 low-risk human papillomavirus (HPV) genotypes. It is based on direct PCR from crude-cell extracts, automatic flow-through hybridization, and colorimetric detection. The aim of this study was to evaluate the performance of HPV Direct Flow CHIP in the analysis of 947 samples from routine cervical screening or the follow-up of abnormal Pap smears. The specimens were dry swab samples, liquid-based cytology samples, or formalin-fixed paraffin-embedded tissues. The genotype distribution was in agreement with known epidemiological data for the Spanish population. Three different subgroups of the samples were also tested by Linear Array (LA) HPV Genotyping Test (n=108), CLART HPV2 (n=82), or Digene Hybrid Capture 2 (HC2) HPV DNA Test (n=101). HPV positivity was 73.6% by HPV Direct Flow CHIP versus 67% by LA, 65.9% by HPV Direct Flow CHIP versus 59.8% by CLART, and 62.4% by HPV Direct Flow CHIP versus 42.6% by HC2. HPV Direct Flow CHIP showed a positive agreement of 88.6% with LA (k=0.798), 87.3% with CLART (k=0.818), and 68.2% with HC2 (k=0.618). In conclusion, HPV Direct Flow CHIP results were comparable with those of the other methods tested. Although further investigation is needed to compare the performance of this new test with a gold-standard reference method, these preliminary findings evidence the potential value of HPV Direct Flow CHIP in HPV vaccinology and epidemiology studies.
NASA Technical Reports Server (NTRS)
Interrante, Victoria
1997-01-01
The three-dimensional shape and relative depth of a smoothly curving layered transparent surface may be communicated particularly effectively when the surface is artistically enhanced with sparsely distributed opaque detail. This paper describes how the set of principal directions and principal curvatures specified by local geometric operators can be understood to define a natural 'flow' over the surface of an object, and can be used to guide the placement of the lines of a stroke texture that seeks to represent 3D shape information in a perceptually intuitive way. The driving application for this work is the visualization of layered isovalue surfaces in volume data, where the particular identity of an individual surface is not generally known a priori and observers will typically wish to view a variety of different level surfaces from the same distribution, superimposed over underlying opaque structures. By advecting an evenly distributed set of tiny opaque particles, and the empty space between them, via 3D line integral convolution through the vector field defined by the principal directions and principal curvatures of the level surfaces passing through each gridpoint of a 3D volume, it is possible to generate a single scan-converted solid stroke texture that may intuitively represent the essential shape information of any level surface in the volume. To generate longer strokes over more highly curved areas, where the directional information is both most stable and most relevant, and to simultaneously downplay the visual impact of directional information in the flatter regions, one may dynamically redefine the length of the filter kernel according to the magnitude of the maximum principal curvature of the level surface at the point around which it is applied.
NASA Technical Reports Server (NTRS)
Zell, P. T.; Hoffmann, J.; Sandlin, D. R.
1985-01-01
A study was performed in order to develop the criteria for the selection of flow direction indicators for use in the Integrated Systems Tests (ISTs) of the 40 by 80/80 by 120 Foot Wind Tunnel System. The problems, requirements, and limitations of flow direction measurement in the wind tunnel were investigated. The locations and types of flow direction measurements planned in the facility were discussed. A review of current methods of flow direction measurement was made and the most suitable technique for each location was chosen. A flow direction vane for each location was chosen. A flow direction vane that employs a Hall Effect Transducer was then developed and evaluated for application during the ISTs.
Integrated method for the measurement of trace atmospheric bases
NASA Astrophysics Data System (ADS)
Key, D.; Stihle, J.; Petit, J.-E.; Bonnet, C.; Depernon, L.; Liu, O.; Kennedy, S.; Latimer, R.; Burgoyne, M.; Wanger, D.; Webster, A.; Casunuran, S.; Hidalgo, S.; Thomas, M.; Moss, J. A.; Baum, M. M.
2011-09-01
Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace atmospheric nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications, as supported by field measurements in an urban park and in the exhaust of on-road vehicles.
Integrated method for the measurement of trace nitrogenous atmospheric bases
NASA Astrophysics Data System (ADS)
Key, D.; Stihle, J.; Petit, J.-E.; Bonnet, C.; Depernon, L.; Liu, O.; Kennedy, S.; Latimer, R.; Burgoyne, M.; Wanger, D.; Webster, A.; Casunuran, S.; Hidalgo, S.; Thomas, M.; Moss, J. A.; Baum, M. M.
2011-12-01
Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace, atmospheric, gaseous nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications (e.g., methylamine, 1 pptv; ethylamine, 2 pptv; morpholine, 1 pptv; aniline, 1 pptv; hydrazine, 0.1 pptv; methylhydrazine, 2 pptv), as supported by field measurements in an urban park and in the exhaust of on-road vehicles.
Hutchinson, R.L.; Hamilton, V.A.; Istrail, G.G.; Espinoza, J.; Murphy, M.D.
1997-11-01
This report describes the results of a Sandia-funded laboratory-directed research and development project titled {open_quotes}Integrated and Robust Security Infrastructure{close_quotes} (IRSI). IRSI was to provide a broad range of commercial-grade security services to any software application. IRSI has two primary goals: application transparency and manageable public key infrastructure. IRSI must provide its security services to any application without the need to modify the application to invoke the security services. Public key mechanisms are well suited for a network with many end users and systems. There are many issues that make it difficult to deploy and manage a public key infrastructure. IRSI addressed some of these issues to create a more manageable public key infrastructure.
Technical evaluation of a USSC integrated/direct mount PV roofing module system at NREL
NASA Astrophysics Data System (ADS)
Strand, T.; Hansen, R.; Mrig, L.
1996-01-01
The results of a 16 month technical evaluation performed on a nominal 1 kWac utility-interconnect amorphous silicon PV system deployed at the National Renewable Energy Laboratory's PV outdoor test site are given here. The system employs 64 prototype United Solar Systems Corp. Integrated/Direct Mount PV Roofing Molecules mounted on simulated attic/roof structures. In this paper we show that the PV array fill factor has been relatively stable with respect to time and that the seasonal variations in performance can be largely attributed to seasonal variations in current. We also show that in determining the summer and winter ac power output, the summation of the manufacturer-supplied module peak powers at STC for a similarly located and configured a-Si PV array should be derated by factors of approximately of 0.83 and 0.78 for summer and winter operation, respectively.
Technical evaluation of a USSC Integrated/Direct Mount PV Roofing Module system at NREL
NASA Astrophysics Data System (ADS)
Strand, Troy; Hansen, Robert; Mrig, Laxmi
1995-05-01
The results of a 16 month technical evaluation performed on a nominal 1 kW(sub ac) utility-interconnect amorphous silicon PV system deployed at the National Renewable Energy Laboratory's PV outdoor test site are given here. The system employs 64 prototype United Solar Systems Corp. Integrated/Direct Mount PV Roofing Modules mounted on simulated attic/roof structures. In this paper we show that the PV array fill factor has been relatively stable with respect to time and that the seasonal variations in performance can be largely attributed to seasonal variations in current. We also show that in determining the summer and winter ac power output, the summation of the manufacturer-supplied module peak powers at STC for a similarly located and configured a-Si PV array should be derated by factors of approximately of 0.83 and 0.78 for summer and winter operation, respectively.
Mitchell, C G; Freels, S; Creticos, C M; Oltean, A; Douglas, R
2007-04-01
Various interventions have been proposed to address these ongoing needs of HIV-positive patients as they encounter challenges with medication adherence and risk reduction. This report presents the findings of a study that pilots 'DAART+', an intervention that integrates modified directly observed therapy (MDOT), and risk reduction counseling for a population of marginally housed, substance-using persons. The pilot study intended to assess the feasibility of the intervention and to obtain data to assess the intervention's potential effectiveness. The preliminary data reveal that 83% of participants who completed the intervention (n=18) had undetectable viral load (VL) (VL< or =400 copies/mL) which represents a 2.15 log(10) decrease from baseline. Risk behaviors also changed modestly with self-reported increases in condom usage.
Integration of new communications and mast subsystems on an Omni-Directional Inspection Robot (ODIS)
NASA Astrophysics Data System (ADS)
Hunt, Shawn; Li, Yung-Sen; Witus, Gary; Walter, Steven; Ellis, R. Darin; Auner, Gregory; Cao, Alex; Pandya, Abhilash
2007-10-01
Our research has focused on how to expand the capabilities of an Omni-Directional Inspection Robot (ODIS) to assist in vehicle inspections at traffic control checkpoints with a standoff distance of 450m. We have implemented an mast, extendible to eight feet, capable of carrying a sensor payload that has an RS-232 connection with a simple set of commands to control its operation. We have integrated a communications chain that provides the desired distance and sufficient speed to transmit a live digital feed to the operator control unit (OCU). We have also created a physically-based simulation of ODIS and our mast inside of Webots and have taken data to calibrate a motion response model.
NASA Astrophysics Data System (ADS)
Rosenbaum, Joyce E.
2011-12-01
Commercial air traffic is anticipated to increase rapidly in the coming years. The impact of aviation noise on communities surrounding airports is, therefore, a growing concern. Accurate prediction of noise can help to mitigate the impact on communities and foster smoother integration of aerospace engineering advances. The problem of accurate sound level prediction requires careful inclusion of all mechanisms that affect propagation, in addition to correct source characterization. Terrain, ground type, meteorological effects, and source directivity can have a substantial influence on the noise level. Because they are difficult to model, these effects are often included only by rough approximation. This dissertation presents a model designed for sound propagation over uneven terrain, with mixed ground type and realistic meteorological conditions. The model is a hybrid of two numerical techniques: the parabolic equation (PE) and fast field program (FFP) methods, which allow for physics-based inclusion of propagation effects and ensure the low frequency content, a factor in community impact, is predicted accurately. Extension of the hybrid model to a pseudo-three-dimensional representation allows it to produce aviation noise contour maps in the standard form. In order for the model to correctly characterize aviation noise sources, a method of representing arbitrary source directivity patterns was developed for the unique form of the parabolic equation starting field. With this advancement, the model can represent broadband, directional moving sound sources, traveling along user-specified paths. This work was prepared for possible use in the research version of the sound propagation module in the Federal Aviation Administration's new standard predictive tool.
Error Reduction Methods for Integrated-path Differential-absorption Lidar Measurements
NASA Technical Reports Server (NTRS)
Chen, Jeffrey R.; Numata, Kenji; Wu, Stewart T.
2012-01-01
We report new modeling and error reduction methods for differential-absorption optical-depth (DAOD) measurements of atmospheric constituents using direct-detection integrated-path differential-absorption lidars. Errors from laser frequency noise are quantified in terms of the line center fluctuation and spectral line shape of the laser pulses, revealing relationships verified experimentally. A significant DAOD bias is removed by introducing a correction factor. Errors from surface height and reflectance variations can be reduced to tolerable levels by incorporating altimetry knowledge and "log after averaging", or by pointing the laser and receiver to a fixed surface spot during each wavelength cycle to shorten the time of "averaging before log".
Error reduction methods for integrated-path differential-absorption lidar measurements.
Chen, Jeffrey R; Numata, Kenji; Wu, Stewart T
2012-07-01
We report new modeling and error reduction methods for differential-absorption optical-depth (DAOD) measurements of atmospheric constituents using direct-detection integrated-path differential-absorption lidars. Errors from laser frequency noise are quantified in terms of the line center fluctuation and spectral line shape of the laser pulses, revealing relationships verified experimentally. A significant DAOD bias is removed by introducing a correction factor. Errors from surface height and reflectance variations can be reduced to tolerable levels by incorporating altimetry knowledge and "log after averaging", or by pointing the laser and receiver to a fixed surface spot during each wavelength cycle to shorten the time of "averaging before log".
Direct measurement of the spatial Wigner function with area-integrated detection.
Mukamel, Eran; Banaszek, Konrad; Walmsley, Ian A; Dorrer, Christophe
2003-08-01
We demonstrate experimentally a novel technique for characterizing transverse spatial coherence by using the Wigner distribution function. The method is based on the measurement of interference between a pair of rotated and displaced replicas of the input beam with an area-integrating detector, and it provides an optimal signal-to-noise ratio in regimes when array detectors are not available. We analyze the quantum-optical picture of the presented measurement for single-photon signals and discuss possible applications in quantum information processing. PMID:12906075
Polymer optical fibers integrated directly into 3D orthogonal woven composites for sensing
NASA Astrophysics Data System (ADS)
Hamouda, Tamer; Seyam, Abdel-Fattah M.; Peters, Kara
2015-02-01
This study demonstrates that standard polymer optical fibers (POF) can be directly integrated into composites from 3D orthogonal woven preforms during the weaving process and then serve as in-situ sensors to detect damage due to bending or impact loads. Different composite samples with embedded POF were fabricated of 3D orthogonal woven composites with different parameters namely number of y-/x-layers and x-yarn density. The signal of POF was not affected significantly by the preform structure. During application of resin using VARTM technique, significant drop in backscattering level was observed due to pressure caused by vacuum on the embedded POF. Measurements of POF signal while in the final composites after resin cure indicated that the backscattering level almost returned to the original level of un-embedded POF. The POF responded to application of bending and impact loads to the composite with a reduction in the backscattering level. The backscattering level almost returned back to its original level after removing the bending load until damage was present in the composite. Similar behavior occurred due to impact events. As the POF itself is used as the sensor and can be integrated throughout the composite, large sections of future 3D woven composite structures could be monitored without the need for specialized sensors or complex instrumentation.
Nitrosi, Andrea; Bertolini, Marco; Notari, Pietro; Botti, Andrea; Ginocchi, Vladimiro; Tondelli, Giulio; Iori, Mauro; Pattacini, Pierpaolo
2013-06-01
In RIS-PACS systems, potential errors occurring during the execution of a radiologic examination can amplify the clinical risks of the patient during subsequent treatments, e.g., of oncologic patients or of those who must do additional treatments based on the initial diagnosis. In Reggio Emilia Province Diagnostic Imaging Department (REDID) we experienced different strategies to reduce clinical risks due to patient reconciliation errors. In 2010, we developed a procedure directly integrated in our RIS-PACS that uses Health Level 7 (HL7) standard messaging, which generates an overlay with the text "under investigation" on the images of the study to be corrected. All the healthcare staff is informed of the meaning of that overlay, and only the radiologist and the emergency services staff can consult these images on PACS. The elimination of image overlay and of any access limitation to PACS was triggered to confirm of the right correction made by RIS-PACS system administrator (SA). The RIS-PACS integrated tool described in this paper allows technologists and radiologists to efficiently highlight patient exam errors and to inform all the users to minimize the overall clinical risks, with a significant savings in costs. Over the years, we have observed a steady decrease in the percentage of reconciled studies. Error reconciliation requires an effective and efficient mechanism. The RIS-PACS integrated tool described in this paper enables technologists and radiologists to quickly and efficiently highlight patient exam errors and inform all the users. Next generation of RIS-PACS could be equipped with similar reconciliation tools. PMID:23224607
Nitrosi, Andrea; Bertolini, Marco; Notari, Pietro; Botti, Andrea; Ginocchi, Vladimiro; Tondelli, Giulio; Iori, Mauro; Pattacini, Pierpaolo
2013-06-01
In RIS-PACS systems, potential errors occurring during the execution of a radiologic examination can amplify the clinical risks of the patient during subsequent treatments, e.g., of oncologic patients or of those who must do additional treatments based on the initial diagnosis. In Reggio Emilia Province Diagnostic Imaging Department (REDID) we experienced different strategies to reduce clinical risks due to patient reconciliation errors. In 2010, we developed a procedure directly integrated in our RIS-PACS that uses Health Level 7 (HL7) standard messaging, which generates an overlay with the text "under investigation" on the images of the study to be corrected. All the healthcare staff is informed of the meaning of that overlay, and only the radiologist and the emergency services staff can consult these images on PACS. The elimination of image overlay and of any access limitation to PACS was triggered to confirm of the right correction made by RIS-PACS system administrator (SA). The RIS-PACS integrated tool described in this paper allows technologists and radiologists to efficiently highlight patient exam errors and to inform all the users to minimize the overall clinical risks, with a significant savings in costs. Over the years, we have observed a steady decrease in the percentage of reconciled studies. Error reconciliation requires an effective and efficient mechanism. The RIS-PACS integrated tool described in this paper enables technologists and radiologists to quickly and efficiently highlight patient exam errors and inform all the users. Next generation of RIS-PACS could be equipped with similar reconciliation tools.
New conceptual method for directly cooling the target biological tissues
NASA Astrophysics Data System (ADS)
Ji, Yan; Liu, Jing
2005-01-01
Hypothermia is a commonly adopted strategy to decrease the cerebral oxygen demands, which is critical for the patient to sustain longer time when subjected to a hypoxia. However, when circulatory arrest occurs, the traditional approaches such as selective brain cooling (SBC), systemic body cooling or perfusing cool blood are often not very helpful due to their slow cooling rates in preventing the tendency of a slight cerebral temperature increase at the onset of circulatory arrest. To resolve such difficult issue, a new conceptual volumetric cooling method (VCM) through minimally invasive injection of physiological coolant was proposed in this study. A heat and fluid transport model based on porous medium configuration was established to describe the thermal responses of brain tissues during hypothermia resuscitation. Theoretical calculations indicated that VCM could significantly improve the cooling rate in the deep part of the biological tissues within a desired period of time. To further test this approach, a series of either in vitro or in vivo animal experiments were performed, which also strongly supported the theoretical predictions and indicated that VCM was well appropriate for the localized cooling of target tissues. The concept of the present VCM could also possibly be extended to more wide clinical situations, when an instant and highly localized cooling for the specific organs or tissues are urgently requested. It also raised challenging issues such as injury or negative effect for the clinical operation of this VCM, which need to be addressed in the coming study.
Recent developments in the direct-current geoelectrical imaging method
NASA Astrophysics Data System (ADS)
Loke, M. H.; Chambers, J. E.; Rucker, D. F.; Kuras, O.; Wilkinson, P. B.
2013-08-01
There have been major improvements in instrumentation, field survey design and data inversion techniques for the geoelectrical method over the past 25 years. Multi-electrode and multi-channel systems have made it possible to conduct large 2-D, 3-D and even 4-D surveys efficiently to resolve complex geological structures that were not possible with traditional 1-D surveys. Continued developments in computer technology, as well as fast data inversion techniques and software, have made it possible to carry out the interpretation on commonly available microcomputers. Multi-dimensional geoelectrical surveys are now widely used in environmental, engineering, hydrological and mining applications. 3-D surveys play an increasingly important role in very complex areas where 2-D models suffer from artifacts due to off-line structures. Large areas on land and water can be surveyed rapidly with computerized dynamic towed resistivity acquisition systems. The use of existing metallic wells as long electrodes has improved the detection of targets in areas where they are masked by subsurface infrastructure. A number of PC controlled monitoring systems are also available to measure and detect temporal changes in the subsurface. There have been significant advancements in techniques to automatically generate optimized electrodes array configurations that have better resolution and depth of investigation than traditional arrays. Other areas of active development include the translation of electrical values into geological parameters such as clay and moisture content, new types of sensors, estimation of fluid or ground movement from time-lapse images and joint inversion techniques. In this paper, we investigate the recent developments in geoelectrical imaging and provide a brief look into the future of where the science may be heading.
A Direct and Rapid Method to Determine Cyanide in Urine by Capillary Electrophoresis
Zhang, Qiyang; Maddukuri, Naveen; Gong, Maojun
2015-01-01
Cyanides are poisonous chemicals that widely exist in nature and industrial processes as well as accidental fires. Rapid and accurate determination of cyanide exposure would facilitate forensic investigation, medical diagnosis, and chronic cyanide monitoring. Here, a rapid and direct method was developed for the determination of cyanide ions in urinary samples. This technique was based on an integrated capillary electrophoresis system coupled with laser-induced fluorescence (LIF) detection. Cyanide ions were derivatized with naphthalene-2,3-dicarboxaldehyde (NDA) and a primary amine (glycine) for LIF detection. Three separate reagents, NDA, glycine, and cyanide sample, were mixed online, which secured uniform conditions between samples for cyanide derivatization and reduced the risk of precipitation formation of mixtures. Conditions were optimized; the derivatization was completed in 2-4 minutes, and the separation was observed in 25 s. The limit of detection (LOD) was 4.0 nM at 3-fold signal-to-noise ratio for standard cyanide in buffer. The cyanide levels in urine samples from smokers and non-smokers were determined by using the method of standard addition, which demonstrated significant difference of cyanide levels in urinary samples from the two groups of people. The developed method was rapid and accurate, and is anticipated to be applicable to cyanide detection in waste water with appropriate modification. PMID:26342870
A direct and rapid method to determine cyanide in urine by capillary electrophoresis.
Zhang, Qiyang; Maddukuri, Naveen; Gong, Maojun
2015-10-01
Cyanides are poisonous chemicals that widely exist in nature and industrial processes as well as accidental fires. Rapid and accurate determination of cyanide exposure would facilitate forensic investigation, medical diagnosis, and chronic cyanide monitoring. Here, a rapid and direct method was developed for the determination of cyanide ions in urinary samples. This technique was based on an integrated capillary electrophoresis system coupled with laser-induced fluorescence (LIF) detection. Cyanide ions were derivatized with naphthalene-2,3-dicarboxaldehyde (NDA) and a primary amine (glycine) for LIF detection. Three separate reagents, NDA, glycine, and cyanide sample, were mixed online, which secured uniform conditions between samples for cyanide derivatization and reduced the risk of precipitation formation of mixtures. Conditions were optimized; the derivatization was completed in 2-4min, and the separation was observed in 25s. The limit of detection (LOD) was 4.0nM at 3-fold signal-to-noise ratio for standard cyanide in buffer. The cyanide levels in urine samples from smokers and non-smokers were determined by using the method of standard addition, which demonstrated significant difference of cyanide levels in urinary samples from the two groups of people. The developed method was rapid and accurate, and is anticipated to be applicable to cyanide detection in waste water with appropriate modification.
Integrated and consumer-directed care: a necessary paradigm shift for rural chronic ill health.
Ranson, Nicole E; Terry, Daniel R; Glenister, Kristen; Adam, Bill R; Wright, Julian
2016-01-01
Chronic ill health has recently emerged as the most important health issue on a global scale. Rural communities are disproportionally affected by chronic ill health. Many health systems are centred on the management of acute conditions and are often poorly equipped to deal with chronic ill health. Cardiovascular disease (CVD) is one of the most prominent chronic ill health conditions and the principal cause of mortality worldwide. In this paper, CVD is used as an example to demonstrate the disparity between rural and urban experience of chronic ill health, access to medical care and clinical outcomes. Advances have been made to address chronic ill health through improving self-management strategies, health literacy and access to medical services. However, given the higher incidence of chronic health conditions and poorer clinical outcomes in rural communities, it is imperative that integrated health care emphasises greater collaboration between services. It is also vital that rural GPs are better supported to work with their patients, and that they use consumer-directed approaches to empower patients to direct and coordinate their own care.
NASA Astrophysics Data System (ADS)
Sun, Tai-Ping; Lu, Yi-Chuan; Shieh, Hsiu-Li; Tang, Shiang-Feng; Lin, Wen-Jen
2013-05-01
This paper proposes dual-mode buffer direct injection (BDI) and direct injection (DI) readout circuit design. The DI readout circuit has the advantage of being a simple circuit, requiring a small layout area, and low power consumption. The internal resistance of the photodetector will affect the photocurrent injection efficiency. We used a buffer amplifier to design the BDI readout circuit since it would reduce the input impedance and raise the injection efficiency. This paper will discuss and analyze the power consumption, injection efficiency, layout area, and circuit noise. The circuit is simulated using a TSMC 0.35 um Mixed Signal 2P4M CMOS 5 V process. The dimension of the pixel area is 30×30 μm. We have designed a 10×8 array for the readout circuit of the interlaced columns. The input current ranges from 1 nA to 10 nA, when the measurement current is 10 pA to 10 nA. The integration time was varied. The circuit output swing was 2 V. The total root mean square noise voltage was 4.84 mV. The signal to noise ratio was 52 dB, and the full chip circuit power consumption was 9.94 mW.
Transient 3d contact problems—NTS method: mixed methods and conserving integration
NASA Astrophysics Data System (ADS)
Hesch, Christian; Betsch, Peter
2011-10-01
The present work deals with a new formulation for transient large deformation contact problems. It is well known, that one-step implicit time integration schemes for highly non-linear systems fail to conserve the total energy of the system. To deal with this drawback, a mixed method is newly proposed in conjunction with the concept of a discrete gradient. In particular, we reformulate the well known and widely-used node-to-segment methods and establish an energy-momentum scheme. The advocated approach ensures robustness and enhanced numerical stability, demonstrated in several three-dimensional applications of the proposed algorithm.
New Methods to Integrate Paleodata Into Climate Models
NASA Astrophysics Data System (ADS)
Otto-Bliesner, Bette L.; Schulz, Michael
2009-09-01
Data-Assimilation Techniques for Paleoclimate Data; Vienna, Austria, 25 April 2009; Data assimilation has become an important approach for estimating or forecasting the state of the atmosphere and oceans. This method, though, is difficult to apply to paleodata due to their sparse spatial distribution and the uncertainties associated with proxy reconstructions. To debate the applicability of the various techniques in a paleoclimate context, a group of 12 scientists from Europe, Japan, and the United States convened at a workshop in Vienna. Participants noted that several groups have recently started to work on the assimilation of paleodata into numerical models of the circulation in the ocean and/or atmosphere. The majority of work has been directed toward estimating the state of the large-scale ocean circulation during the Last Glacial Maximum (LGM; ˜21,000 years ago) because the corresponding proxy data coverage is relatively good. The goal is to find the best estimate of the LGM ocean circulation that is dynamically consistent with model and proxy data. These methods have incorporated tracer observations from sediments, such as stable carbon isotope measurements, over the whole depth range of the oceans to estimate the glacial circulation. A grand challenge for these efforts is a LGM “reanalysis” project, which is aimed at estimating the climate state at LGM as well as the changes from LGM to the present.
Developing integrated methods to address complex resource and environmental issues
Smith, Kathleen S.; Phillips, Jeffrey D.; McCafferty, Anne E.; Clark, Roger N.
2016-02-08
IntroductionThis circular provides an overview of selected activities that were conducted within the U.S. Geological Survey (USGS) Integrated Methods Development Project, an interdisciplinary project designed to develop new tools and conduct innovative research requiring integration of geologic, geophysical, geochemical, and remote-sensing expertise. The project was supported by the USGS Mineral Resources Program, and its products and acquired capabilities have broad applications to missions throughout the USGS and beyond.In addressing challenges associated with understanding the location, quantity, and quality of mineral resources, and in investigating the potential environmental consequences of resource development, a number of field and laboratory capabilities and interpretative methodologies evolved from the project that have applications to traditional resource studies as well as to studies related to ecosystem health, human health, disaster and hazard assessment, and planetary science. New or improved tools and research findings developed within the project have been applied to other projects and activities. Specifically, geophysical equipment and techniques have been applied to a variety of traditional and nontraditional mineral- and energy-resource studies, military applications, environmental investigations, and applied research activities that involve climate change, mapping techniques, and monitoring capabilities. Diverse applied geochemistry activities provide a process-level understanding of the mobility, chemical speciation, and bioavailability of elements, particularly metals and metalloids, in a variety of environmental settings. Imaging spectroscopy capabilities maintained and developed within the project have been applied to traditional resource studies as well as to studies related to ecosystem health, human health, disaster assessment, and planetary science. Brief descriptions of capabilities and laboratory facilities and summaries of some
Method for integrating microelectromechanical devices with electronic circuitry
Barron, Carole C.; Fleming, James G.; Montague, Stephen
1999-01-01
A method is disclosed for integrating one or more microelectromechanical (MEM) devices with electronic circuitry on a common substrate. The MEM device can be fabricated within a substrate cavity and encapsulated with a sacrificial material. This allows the MEM device to be annealed and the substrate planarized prior to forming electronic circuitry on the substrate using a series of standard processing steps. After fabrication of the electronic circuitry, the electronic circuitry can be protected by a two-ply protection layer of titanium nitride (TiN) and tungsten (W) during an etch release process whereby the MEM device is released for operation by etching away a portion of a sacrificial material (e.g. silicon dioxide or a silicate glass) that encapsulates the MEM device. The etch release process is preferably performed using a mixture of hydrofluoric acid (HF) and hydrochloric acid (HCI) which reduces the time for releasing the MEM device compared to use of a buffered oxide etchant. After release of the MEM device, the TiN:W protection layer can be removed with a peroxide-based etchant without damaging the electronic circuitry.
Involving Stakeholders in Building Integrated Fisheries Models Using Bayesian Methods
NASA Astrophysics Data System (ADS)
Haapasaari, Päivi; Mäntyniemi, Samu; Kuikka, Sakari
2013-06-01
A participatory Bayesian approach was used to investigate how the views of stakeholders could be utilized to develop models to help understand the Central Baltic herring fishery. In task one, we applied the Bayesian belief network methodology to elicit the causal assumptions of six stakeholders on factors that influence natural mortality, growth, and egg survival of the herring stock in probabilistic terms. We also integrated the expressed views into a meta-model using the Bayesian model averaging (BMA) method. In task two, we used influence diagrams to study qualitatively how the stakeholders frame the management problem of the herring fishery and elucidate what kind of causalities the different views involve. The paper combines these two tasks to assess the suitability of the methodological choices to participatory modeling in terms of both a modeling tool and participation mode. The paper also assesses the potential of the study to contribute to the development of participatory modeling practices. It is concluded that the subjective perspective to knowledge, that is fundamental in Bayesian theory, suits participatory modeling better than a positivist paradigm that seeks the objective truth. The methodology provides a flexible tool that can be adapted to different kinds of needs and challenges of participatory modeling. The ability of the approach to deal with small data sets makes it cost-effective in participatory contexts. However, the BMA methodology used in modeling the biological uncertainties is so complex that it needs further development before it can be introduced to wider use in participatory contexts.
Full Wave Simulation of Integrated Circuits Using Hybrid Numerical Methods
NASA Astrophysics Data System (ADS)
Tan, Jilin
Transmission lines play an important role in digital electronics, and in microwave and millimeter-wave circuits. Analysis, modeling, and design of transmission lines are critical to the development of the circuitry in the chip, subsystem, and system levels. In the past several decays, at the EM modeling level, the quasi-static approximation has been widely used due to its great simplicity. As the clock rates increase, the inter-connect effects such as signal delay, distortion, dispersion, reflection, and crosstalk, limit the performance of microwave systems. Meanwhile, the quasi-static approach loses its validity for some complex system structures. Since the successful system design of the PCB, MCM, and the chip packaging, rely very much on the computer aided EM level modeling and simulation, many new methods have been developed, such as the full wave approach, to guarantee the successful design. Many difficulties exist in the rigorous EM level analysis. Some of these include the difficulties in describing the behavior of the conductors with finite thickness and finite conductivity, the field singularity, and the arbitrary multilayered multi-transmission lines structures. This dissertation concentrates on the full wave study of the multi-conductor transmission lines with finite conductivity and finite thickness buried in an arbitrary lossy multilayered environment. Two general approaches have been developed. The first one is the integral equation method in which the dyadic Green's function for arbitrary layered media has been correctly formulated and has been tested both analytically and numerically. By applying this method, the double layered high dielectric permitivitty problem and the heavy dielectrical lossy problem in multilayered media in the CMOS circuit design have been solved. The second approach is the edge element method. In this study, the correct functional for the two dimensional propagation problem has been successfully constructed in a rigorous way
Cutting Force Predication Based on Integration of Symmetric Fuzzy Number and Finite Element Method
Wang, Zhanli; Hu, Yanjuan; Wang, Yao; Dong, Chao; Pang, Zaixiang
2014-01-01
In the process of turning, pointing at the uncertain phenomenon of cutting which is caused by the disturbance of random factors, for determining the uncertain scope of cutting force, the integrated symmetric fuzzy number and the finite element method (FEM) are used in the prediction of cutting force. The method used symmetric fuzzy number to establish fuzzy function between cutting force and three factors and obtained the uncertain interval of cutting force by linear programming. At the same time, the change curve of cutting force with time was directly simulated by using thermal-mechanical coupling FEM; also the nonuniform stress field and temperature distribution of workpiece, tool, and chip under the action of thermal-mechanical coupling were simulated. The experimental result shows that the method is effective for the uncertain prediction of cutting force. PMID:24790556
Zero Failure Production Methods Based on a Process Integrated Virtual Control
NASA Astrophysics Data System (ADS)
Hora, P.; Heingärtner, J.; Manopulo, N.; Tong, L.
2011-08-01
Although the virtual methods are nowadays fully established as a widely used tool in the planning and optimization of forming processes they are still completely omitted for a direct, "intelligent" process control in the later production of the parts. The paper presents a proposal for a Process-Integrated-Virtual-Control (PIVC) considering the real process perturbations induced by deviations of material properties as well as by further time dependent process parameters like the tool temperature. For the detection of the material deviations an in-line eddy-current measurement method and the appropriate evaluation method for the definition of the stochastic yield curves will be presented. The paper closes with a virtually taught control system modifying the blank-holder forces in dependency of thermal conditions and material deviations. The goal of this PIVC coupled to in-line process controls is to achieve a Zero Failure production even under alternative time dependent process conditions.
NASA Astrophysics Data System (ADS)
Maupin, Valerie; Näsholm, Sven Peter; Schweitzer, Johannes; Gibbons, Steven J.
2016-04-01
We recently advocated using the reflectivity method, also known as the wavenumber integration method or fast-field program, to model atmospheric infrasound propagation at regional distances. The advantage of the reflectivity method is its ability to model the full wavefield, including diffractive effects with head waves and shadow zone arrivals, in a broad frequency range but still at a relatively low computational cost. Attenuation can easily be included, giving the possibility to analyse relative amplitudes and frequency content of the different arrivals. It has clear advantages compared with ray theory in terms of predicting phases considering the particular frequent occurrence of shadow zone arrivals in infrasound observations. Its main limitation, at least in the traditional form of the method, lies in the fact that it can only handle range-independent models. We presented earlier some reflectivity method simulations of an observed accidental explosion in Norway. Wind intensity and direction are non-negligible parameters for infrasound propagation and these are appropriately taken into account in most infrasound ray-tracing codes. On the other hand, in the previous reflectivity simulations wind was taken into account only through the effective sound speed approximation where the horizontal projection of the wind field is added to the adiabatic sound speed profiles. This approximation is appropriate for dominantly horizontal propagation but can give incorrect arrival times and shadow zone locations for waves which have a significant portion of their propagation path at more vertical incidence, like thermospheric arrivals. We present here how we have modified the original reflectivity algorithm in order to take the wind into account in a more correct fashion, and how this improvement influences the synthetics.
Joining direct and indirect inverse calibration methods to characterize karst, coastal aquifers
NASA Astrophysics Data System (ADS)
De Filippis, Giovanna; Foglia, Laura; Giudici, Mauro; Mehl, Steffen; Margiotta, Stefano; Negri, Sergio
2016-04-01
Parameter estimation is extremely relevant for accurate simulation of groundwater flow. Parameter values for models of large-scale catchments are usually derived from a limited set of field observations, which can rarely be obtained in a straightforward way from field tests or laboratory measurements on samples, due to a number of factors, including measurement errors and inadequate sampling density. Indeed, a wide gap exists between the local scale, at which most of the observations are taken, and the regional or basin scale, at which the planning and management decisions are usually made. For this reason, the use of geologic information and field data is generally made by zoning the parameter fields. However, pure zoning does not perform well in the case of fairly complex aquifers and this is particularly true for karst aquifers. In fact, the support of the hydraulic conductivity measured in the field is normally much smaller than the cell size of the numerical model, so it should be upscaled to a scale consistent with that of the numerical model discretization. Automatic inverse calibration is a valuable procedure to identify model parameter values by conditioning on observed, available data, limiting the subjective evaluations introduced with the trial-and-error technique. Many approaches have been proposed to solve the inverse problem. Generally speaking, inverse methods fall into two groups: direct and indirect methods. Direct methods allow determination of hydraulic conductivities from the groundwater flow equations which relate the conductivity and head fields. Indirect methods, instead, can handle any type of parameters, independently from the mathematical equations that govern the process, and condition parameter values and model construction on measurements of model output quantities, compared with the available observation data, through the minimization of an objective function. Both approaches have pros and cons, depending also on model complexity. For
Developing integrated methods to address complex resource and environmental issues
Smith, Kathleen S.; Phillips, Jeffrey D.; McCafferty, Anne E.; Clark, Roger N.
2016-02-08
IntroductionThis circular provides an overview of selected activities that were conducted within the U.S. Geological Survey (USGS) Integrated Methods Development Project, an interdisciplinary project designed to develop new tools and conduct innovative research requiring integration of geologic, geophysical, geochemical, and remote-sensing expertise. The project was supported by the USGS Mineral Resources Program, and its products and acquired capabilities have broad applications to missions throughout the USGS and beyond.In addressing challenges associated with understanding the location, quantity, and quality of mineral resources, and in investigating the potential environmental consequences of resource development, a number of field and laboratory capabilities and interpretative methodologies evolved from the project that have applications to traditional resource studies as well as to studies related to ecosystem health, human health, disaster and hazard assessment, and planetary science. New or improved tools and research findings developed within the project have been applied to other projects and activities. Specifically, geophysical equipment and techniques have been applied to a variety of traditional and nontraditional mineral- and energy-resource studies, military applications, environmental investigations, and applied research activities that involve climate change, mapping techniques, and monitoring capabilities. Diverse applied geochemistry activities provide a process-level understanding of the mobility, chemical speciation, and bioavailability of elements, particularly metals and metalloids, in a variety of environmental settings. Imaging spectroscopy capabilities maintained and developed within the project have been applied to traditional resource studies as well as to studies related to ecosystem health, human health, disaster assessment, and planetary science. Brief descriptions of capabilities and laboratory facilities and summaries of some
A direct method of measuring gaseous emissions from naturally ventilated dairy barns
NASA Astrophysics Data System (ADS)
Joo, H. S.; Ndegwa, P. M.; Heber, A. J.; Bogan, B. W.; Ni, J.-Q.; Cortus, E. L.; Ramirez-Dorronsoro, J. C.
2014-04-01
Air pollutant emission rates from mechanically ventilated (MV) dairy barns are determined from the product of the differences in concentrations of pollutants in air at the inlet and exhaust points and the corresponding ventilation rates. In contrast to well defined entry and exit points in MV barns, large area air inlets or outlets characterize naturally ventilated (NV) freestall dairy barns. Complicating this scenario even more, pertinent airflow characteristics (velocity and direction) necessary for determining ventilation rates vary continuously, both temporally and spatially. This paper describes implementation of a direct method, generally equivalent to the approach used for MV barns, for determining air emission rates of NV barns. Ultrasonic anemometers (sonics) located at salient points in the barn openings mapped air inflow and outflow velocities necessary to calculate ventilation rates. Pollutant concentrations in the air entering or leaving the barn during a given period were measured at sampling points located next to the anemometers. The air inflow rates were, in general, higher than the air outflow rates from the barns, but diurnal profiles were similar. The observed ventilation characteristics were consistent with prevailing wind directions. Air inflows were observed predominantly at windward openings of the barn, while the outflows were mainly at the barn's leeward openings. Results indicated that either: (i) the average of the air inflow and outflow rates (averaging approach), or (ii) the air inflow rates (inflow-only approach) were credible representations of ventilation rates. Results also revealed use of an on-site weather station and one sonic mounted in the middle of each wall of the barn as a possible approach for determining barn ventilation rates. The suggested use of ventilation rates for interpolating missing concentrations from intermittent gas measurements could potentially increase the integrity of emission rates at significantly lower
Ion-beam apparatus and method for analyzing and controlling integrated circuits
Campbell, A.N.; Soden, J.M.
1998-12-01
An ion-beam apparatus and method for analyzing and controlling integrated circuits are disclosed. The ion-beam apparatus comprises a stage for holding one or more integrated circuits (ICs); a source means for producing a focused ion beam; and a beam-directing means for directing the focused ion beam to irradiate a predetermined portion of the IC for sufficient time to provide an ion-beam-generated electrical input signal to a predetermined element of the IC. The apparatus and method have applications to failure analysis and developmental analysis of ICs and permit an alteration, control, or programming of logic states or device parameters within the IC either separate from or in combination with applied electrical stimulus to the IC for analysis thereof. Preferred embodiments of the present invention including a secondary particle detector and an electron floodgun further permit imaging of the IC by secondary ions or electrons, and allow at least a partial removal or erasure of the ion-beam-generated electrical input signal. 4 figs.
Ion-beam apparatus and method for analyzing and controlling integrated circuits
Campbell, Ann N.; Soden, Jerry M.
1998-01-01
An ion-beam apparatus and method for analyzing and controlling integrated circuits. The ion-beam apparatus comprises a stage for holding one or more integrated circuits (ICs); a source means for producing a focused ion beam; and a beam-directing means for directing the focused ion beam to irradiate a predetermined portion of the IC for sufficient time to provide an ion-beam-generated electrical input signal to a predetermined element of the IC. The apparatus and method have applications to failure analysis and developmental analysis of ICs and permit an alteration, control, or programming of logic states or device parameters within the IC either separate from or in combination with applied electrical stimulus to the IC for analysis thereof. Preferred embodiments of the present invention including a secondary particle detector and an electron floodgun further permit imaging of the IC by secondary ions or electrons, and allow at least a partial removal or erasure of the ion-beam-generated electrical input signal.
NASA Technical Reports Server (NTRS)
Sidi, A.; Israeli, M.
1986-01-01
High accuracy numerical quadrature methods for integrals of singular periodic functions are proposed. These methods are based on the appropriate Euler-Maclaurin expansions of trapezoidal rule approximations and their extrapolations. They are used to obtain accurate quadrature methods for the solution of singular and weakly singular Fredholm integral equations. Such periodic equations are used in the solution of planar elliptic boundary value problems, elasticity, potential theory, conformal mapping, boundary element methods, free surface flows, etc. The use of the quadrature methods is demonstrated with numerical examples.
A direct method for measuring acoustic ground impedance in long-range propagation experiments.
Soh, Jin H; Gilbert, Kenneth E; Frazier, W M Garth; Talmadge, Carrick L; Waxler, Roger
2010-11-01
A method is reported for determining ground impedance in long-range propagation experiments by using the definition of impedance directly. The method is envisioned as way of measuring the impedence at multiple locations along the propagation path, using the signals broadcast during the experiment itself. In a short-range (10 m) test, the direct method was in good agreement with a more conventional model-based least-squares method. The utility of the direct method was demonstrated in a 400 m propagation experiment in a agricultural field. The resulting impedance was consistent with the impedance measured previously in the same field. PMID:21110540
Lee, Yuh-Shiow
2013-01-01
This study examined how encoding and retrieval factors affected directed forgetting costs and benefits in an item-method procedure. Experiment 1 used a typical item-method procedure and revealed a levels-of-processing effect in overall recall. However, the deep encoding condition showed a smaller directed forgetting effect than the shallow encoding conditions. More importantly, "remember" (R) words were selectively rehearsed as indicated by greater recall from the primacy portion of the list and more apt to be recalled before "forget" (F) words. Experiment 2 showed that a deep encoding operation reduced directed forgetting costs and that directed forgetting benefits occurred only when R words were recalled before F words. These findings supported the hypotheses that encoding manipulation affected directed forgetting costs and that directed forgetting benefits were associated with output order bias. Results were discussed in terms of mechanisms that produce item-method directed forgetting.
A Multi-Index Integrated Change detection method for updating the National Land Cover Database
Jin, Suming; Yang, Limin; Xian, George Z.; Danielson, Patrick; Homer, Collin G.
2010-01-01
Land cover change is typically captured by comparing two or more dates of imagery and associating spectral change with true thematic change. A new change detection method, Multi-Index Integrated Change (MIIC), has been developed to capture a full range of land cover disturbance patterns for updating the National Land Cover Database (NLCD). Specific indices typically specialize in identifying only certain types of disturbances; for example, the Normalized Burn Ratio (NBR) has been widely used for monitoring fire disturbance. Recognizing the potential complementary nature of multiple indices, we integrated four indices into one model to more accurately detect true change between two NLCD time periods. The four indices are NBR, Normalized Difference Vegetation Index (NDVI), Change Vector (CV), and a newly developed index called the Relative Change Vector (RCV). The model is designed to provide both change location and change direction (e.g. biomass increase or biomass decrease). The integrated change model has been tested on five image pairs from different regions exhibiting a variety of disturbance types. Compared with a simple change vector method, MIIC can better capture the desired change without introducing additional commission errors. The model is particularly accurate at detecting forest disturbances, such as forest harvest, forest fire, and forest regeneration. Agreement between the initial change map areas derived from MIIC and the retained final land cover type change areas will be showcased from the pilot test sites.
A Multi-Index Integrated Change Detection Method for Updating the National Land Cover Database
NASA Astrophysics Data System (ADS)
Jin, S.; Yang, L.; Xian, G. Z.; Danielson, P.; Homer, C.
2010-12-01
Land cover change is typically captured by comparing two or more dates of imagery and associating spectral change with true thematic change. A new change detection method, Multi-Index Integrated Change (MIIC), has been developed to capture a full range of land cover disturbance patterns for updating the National Land Cover Database (NLCD). Specific indices typically specialize in identifying only certain types of disturbances; for example, the Normalized Burn Ratio (NBR) has been widely used for monitoring fire disturbance. Recognizing the potential complementary nature of multiple indices, we integrated four indices into one model to more accurately detect true change between two NLCD time periods. The four indices are NBR, Normalized Difference Vegetation Index (NDVI), Change Vector (CV), and a newly developed index called the Relative Change Vector (RCV). The model is designed to provide both change location and change direction (e.g. biomass increase or biomass decrease). The integrated change model has been tested on five image pairs from different regions exhibiting a variety of disturbance types. Compared with a simple change vector method, MIIC can better capture the desired change without introducing additional commission errors. The model is particularly accurate at detecting forest disturbances, such as forest harvest, forest fire, and forest regeneration. Agreement between the initial change map areas derived from MIIC and the retained final land cover type change areas will be showcased from the pilot test sites.
VALUE - Validating and Integrating Downscaling Methods for Climate Change Research
NASA Astrophysics Data System (ADS)
Maraun, Douglas; Widmann, Martin; Benestad, Rasmus; Kotlarski, Sven; Huth, Radan; Hertig, Elke; Wibig, Joanna; Gutierrez, Jose
2013-04-01
this exercise will directly provide end users with important information about the uncertainty of regional climate scenarios, and will furthermore provide the basis for further developing downscaling methods. This presentation will provide background information on VALUE and discuss the identified characteristics and the validation framework.
NASA Technical Reports Server (NTRS)
Gaucher, Brian P. (Inventor); Grzyb, Janusz (Inventor); Liu, Duixian (Inventor); Pfeiffer, Ullrich R. (Inventor)
2008-01-01
Apparatus and methods are provided for packaging IC chips together with integrated antenna modules designed to provide a closed EM (electromagnetic) environment for antenna radiators, thereby allowing antennas to be designed independent from the packaging technology.
NASA Astrophysics Data System (ADS)
Chilcote, Jeffrey Kaplan
This thesis is focused on the development and testing of a new instrument capable of finding and characterizing recently-formed Jupiter-sized planets orbiting other stars. To observe these planets, I present the design, construction and testing of the Gemini Planet Imager (GPI) Integral Field Spectrograph (IFS). GPI is a facility class instrument for the Gemini Observatory with the primary goal of directly detecting young Jovian planets. The GPI IFS utilizes an infrared transmissive lenslet array to sample a rectangular 2.7 x 2.7 arcsecond field of view and provide low-resolution spectra across five bands between 1 and 2.5 mum. The dispersing element can be replaced with a Wollaston prism to provide broadband polarimetry across the same five filter bands. The IFS construction was based at the University of California, Los Angeles in collaboration with the Universite de Montreal, Immervision and Lawrence Livermore National Laboratory. I will present performance results, from in-lab testing, of the Integral Field Spectrograph (IFS) for the Gemini Planet Imager (GPI). The IFS is a large, complex, cryogenic, optical system requiring several years of development and testing. I will present the design and integration of the mechanical and optical performance of the spectrograph optics. The IFS passed its pre-ship review in 2011 and was shipped to University of California, Santa Cruz for integration with the remaining sub-systems of GPI. The UCLA built GPI IFS was integrated with the rest of GPI and is delivering high quality spectral datacubes of GPI's coronagraphic field. Using the NIRC2 instrument located at the Keck Observatory, my collaborators and I observed the planetary companion to beta Pictoris in L' (3.5--4.1mum). Observations taken in the fall of 2009 and 2012 are used to find the location and inclination of the planet relative to the massive debris disk orbiting beta Pictoris. We find that the planet's orbit has a position angle on the sky of 211
Pattern recognition methods and air pollution source identification. [based on wind direction
NASA Technical Reports Server (NTRS)
Leibecki, H. F.; King, R. B.
1978-01-01
Directional air samplers, used for resolving suspended particulate matter on the basis of time and wind direction were used to assess the feasibility of characterizing and identifying emission source types in urban multisource environments. Filters were evaluated for 16 elements and X-ray fluorescence methods yielded elemental concentrations for direction, day, and the interaction of direction and day. Large numbers of samples are necessary to compensate for large day-to-day variations caused by wind perturbations and/or source changes.
MTF curve integral calculation method and its application in image quality evaluation
NASA Astrophysics Data System (ADS)
Xiao, Ze-xin; Yin, Huang; Ma, Shu-jing
2014-11-01
The optical transfer function (MTF) has been widely used in the design and manufacture of optical system. The area under the MTF curve can show image quality of the optical system directly. However, for a long time, as the evaluation remained at the qualitative level, it has little value in practice. When the author started the research of MTF curve integral calculation method, no related literatures were available. With the aid of the OSLO optical design software, optimized optical system structure and corresponding MTF curve discrete data are obtained by means of iterative optimization with the software. Then, the original MTF curve data are fit by MATLAB software and the integral result of the curve is calculated through the relevant numerical method. With the software programmed by the authors, the subjects planned to be evaluated can be ranked in order of image quality automatically. This method can be used as a criterion for evaluating image quality. Application cases show that the evaluation methodology proposed by author is reliable and can be easily operated. This method is supposed to bring about a new way to evaluate the image quality of optical system with the MTF curve.
Preferences of a Traditional Extension Audience for Self-Directed Delivery Methods.
ERIC Educational Resources Information Center
Caldwell, Allen E.; Richardson, John G.
1995-01-01
North Carolina farmers growing barley (n=20) tested 3 self-directed information delivery methods: fact sheets, fact sheets plus audiocassettes, and an extension bulletin/pamphlet. The fact sheet/cassette was preferred by 17 of 20; they achieved significant knowledge gains with self-directed methods. The fact sheet/cassette was considered…
Gammelsrud, Karianne Wiger; Knudsen, Per Kristian; Høiby, E Arne
2016-10-01
A novel method to detect resistant faecal Enterobacteriaceae was developed by applying MIC-gradient strips directly onto agar plates inoculated with faeces. The method provided the susceptibility pattern (MICs) of the dominant bacterial population directly on the plates and also detected smaller resistant subpopulations with a sensitivity of 1/10(5).
Page, Hector J I; Walters, Daniel; Stringer, Simon M
2015-01-01
Head direction cells fire to signal the direction in which an animal's head is pointing. They are able to track head direction using only internally-derived information (path integration)In this simulation study we investigate the factors that affect path integration accuracy. Specifically, two major limiting factors are identified: rise time, the time after stimulation it takes for a neuron to start firing, and the presence of symmetric non-offset within-layer recurrent collateral connectivity. On the basis of the latter, the important prediction is made that head direction cell regions directly involved in path integration will not contain this type of connectivity; giving a theoretical explanation for architectural observations. Increased neuronal rise time is found to slow path integration, and the slowing effect for a given rise time is found to be more severe in the context of short conduction delays. Further work is suggested on the basis of our findings, which represent a valuable contribution to understanding of the head direction cell system.
Method for measuring surface shear stress magnitude and direction using liquid crystal coatings
NASA Technical Reports Server (NTRS)
Reda, Daniel C. (Inventor)
1995-01-01
A method is provided for determining surface shear magnitude and direction at every point on a surface. The surface is covered with a shear stress sensitive liquid crystal coating and illuminated by white light from a normal direction. A video camera is positioned at an oblique angle above the surface to observe the color of the liquid crystal at that angle. The shear magnitude and direction are derived from the color information. A method of calibrating the device is also provided.
Chen, Xiang; Nanstad, Randy K; Sokolov, Mikhail A
2014-01-01
The direct current potential drop (DCPD) technique has been applied to derive the J-integral vs. crack growth resistance curve (J-R curve) for fracture toughness characterization of structural materials. The test matrix covered three materials including type 316LN stainless steels, Ni-based alloy 617, and one ferritic-martensitic steel, three specimen configurations including standard compact, single edge bending, and disk-shaped compact specimens, and temperatures ranging from 20 C to 650 C. When compared with baseline J-R curves derived from the ASTM normalization method, the original J-R curves from the DCPD technique yielded much smaller Jq values due to the influence of crack blunting, plastic deformation, etc. on potential drop. To counter these effects, a new procedure for adjusting DCPD J-R curves was proposed. After applying the new adjustment procedure, the average difference in Jq between the DCPD technique and the normalization method was only 5.2% and the difference in tearing modulus was 7.4%. The promising result demonstrates the applicability of the DCPD technique for the J-R curve characterization especially in extreme environments, such as elevated temperatures, where the conventional elastic unloading compliance method faces considerable challenges.
Rapid direct methods for enumeration of specific, active bacteria in water and biofilms
NASA Technical Reports Server (NTRS)
McFeters, G. A.; Pyle, B. H.; Lisle, J. T.; Broadaway, S. C.
1999-01-01
Conventional methods for detecting indicator and pathogenic bacteria in water may underestimate the actual population due to sublethal environmental injury, inability of the target bacteria to take up nutrients and other physiological factors which reduce bacterial culturability. Rapid and direct methods are needed to more accurately detect and enumerate active bacteria. Such a methodological advance would provide greater sensitivity in assessing the microbiological safety of water and food. The principle goal of this presentation is to describe novel approaches we have formulated for the rapid and simultaneous detection of bacteria plus the determination of their physiological activity in water and other environmental samples. The present version of our method involves the concentration of organisms by membrane filtration or immunomagnetic separation and combines an intracellular fluorochrome (CTC) for assessment of respiratory activity plus fluorescent-labelled antibody detection of specific bacteria. This approach has also been successfully used to demonstrate spatial and temporal heterogeneities of physiological activities in biofilms when coupled with cryosectioning. Candidate physiological stains include those capable of determining respiratory activity, membrane potential, membrane integrity, growth rate and cellular enzymatic activities. Results obtained thus far indicate that immunomagnetic separation can provide a high degree of sensitivity in the recovery of seeded target bacteria (Escherichia coli O157:H7) in water and hamburger. The captured and stained target bacteria are then enumerated by either conventional fluorescence microscopy or ChemScan(R), a new instrument that is very sensitive and rapid. The ChemScan(R) laser scanning instrument (Chemunex, Paris, France) provides the detection of individual fluorescently labelled bacterial cells using three emission channels in less than 5 min. A high degree of correlation has been demonstrated between
Methods for Specific Electrode Resistance Measurement during Transcranial Direct Current Stimulation
Khadka, Niranjan; Rahman, Asif; Sarantos, Chris; Truong, Dennis Q.; Bikson, Marom
2014-01-01
Background Transcranial Direct Current Stimulation (tDCS) is investigated to treat a wide range of neuropsychiatric disorders, for rehabilitation, and for enhancing cognitive performance. The monitoring of electrode resistance before and during tDCS is considered important for tolerability and safety, where an unusually high resistance is indicative of undesired electrode or poor skin contact conditions. Conventional resistance measurement methods do not isolate individual electrode resistance but rather measures overall voltage. Moreover, for HD-tDCS devices, cross talk across electrodes makes concurrent resistance monitoring unreliable. Objective We propose a novel method for monitoring of the individual electrode resistance during tDCS, using a super-position of direct current with a test-signal (low-intensity and low-frequency sinusoids with electrode– specific frequencies) and a single sentinel electrode (not used for DC). Methods To validate this methodology, we developed lumped-parameter models of two and multi-electrode tDCS. Approaches with and without a sentinel electrode were solved and underlying assumptions identified. Assumptions were tested and parameterized in healthy participants using forearm stimulation combining tDCS (2 mA) and sinusoidal test-signals (38 μA and 76 μA peak to peak at 1 Hz, 10 Hz, and 100 Hz) and an in vitro test (where varied electrode failure modes were created). DC and AC component voltages across the electrodes were compared and participants were asked to rate subjective pain. Results A sentinel electrode is required to isolate electrode resistance in a two-electrode tDCS system. For multi-electrode resistance tracking, cross talk was aggravated with electrode proximity and current/resistance mismatches, but could be corrected using proposed approaches. Average voltage and average pain scores were not significantly different across test current intensities and frequencies (two-way repeated measures ANOVA) indicating the
Group technology methods for integrated CAD/CAM
NASA Astrophysics Data System (ADS)
Propen, M.; Jacko, J.
1984-10-01
The use of a single product definition and comprehensive database are key factors in integrating CAD and CAM. This paper describes one approach for investigating the scope of developing a full scale Group Technology (GT) system. The prototype GT system discussed required the integration of a decision logic processor, relational database, and design/drafting system, and demonstrated a generative process planning system for a family of gas turbine engine components.
Zhao, Su; Ovadia, Jeremy; Liu, Xinfeng; Zhang, Yong-Tao; Nie, Qing
2011-01-01
For reaction-diffusion-advection equations, the stiffness from the reaction and diffusion terms often requires very restricted time step size, while the nonlinear advection term may lead to a sharp gradient in localized spatial regions. It is challenging to design numerical methods that can efficiently handle both difficulties. For reaction-diffusion systems with both stiff reaction and diffusion terms, implicit integration factor (IIF) method and its higher dimensional analog compact IIF (cIIF) serve as an efficient class of time-stepping methods, and their second order version is linearly unconditionally stable. For nonlinear hyperbolic equations, weighted essentially non-oscillatory (WENO) methods are a class of schemes with a uniformly high-order of accuracy in smooth regions of the solution, which can also resolve the sharp gradient in an accurate and essentially non-oscillatory fashion. In this paper, we couple IIF/cIIF with WENO methods using the operator splitting approach to solve reaction-diffusion-advection equations. In particular, we apply the IIF/cIIF method to the stiff reaction and diffusion terms and the WENO method to the advection term in two different splitting sequences. Calculation of local truncation error and direct numerical simulations for both splitting approaches show the second order accuracy of the splitting method, and linear stability analysis and direct comparison with other approaches reveals excellent efficiency and stability properties. Applications of the splitting approach to two biological systems demonstrate that the overall method is accurate and efficient, and the splitting sequence consisting of two reaction-diffusion steps is more desirable than the one consisting of two advection steps, because CWC exhibits better accuracy and stability. PMID:21666863
Push-through direct injection NMR: an optimized automation method applied to metabolomics
There is a pressing need to increase the throughput of NMR analysis in fields such as metabolomics and drug discovery. Direct injection (DI) NMR automation is recognized to have the potential to meet this need due to its suitability for integration with the 96-well plate format. ...
Integrated low emission cleanup system for direct coal-fueled turbines (electrostatic agglomeration)
Quimby, J.M.; Kumar, K.S.
1992-01-01
The objective of this contract was to investigate the removal of SO[sub x] and particulate matter from direct coal fired combustion gas streams at high temperature and high pressure conditions. This investigation was to be accomplished through a bench scale testing and evaluation program for SO[sub x] removal and the innovative particulate collection concept of particulate growth through electrostatic agglomeration followed by high efficiency mechanical collection. The process goal was to achieve control better than that required by 1979 New Source Performance Standards. During Phase I, the designs of the combustor and gas cleanup apparatus were successfully completed. Hot gas cleanup was designed to be accomplished at temperature levels between 1800[degrees] and 2500[degrees]F at pressures up to 15 atmospheres. The combustor gas flow rate could be varied between 0.2--0.5 pounds per second. The electrostatic agglomerator residence time could be varied between 0.25 to 3 seconds. In Phase II, all components were fabricated, and erected successfully. Test data from shakedown testing was obtained. Unpredictable difficulties in pilot plant erection and shakedown consumed more budget resources than was estimated and as a consequence DOE, METC, decided ft was best to complete the contract at the end of Phase II. Parameters studied in shakedown testing revealed that high-temperature high pressure electrostatics offers an alternative to barrier filtration in hot gas cleanup but more research is needed in successful system integration between the combustor and electrostatic agglomerator.
NASA Astrophysics Data System (ADS)
Hollingsworth, Jennifer A.
2015-09-01
Thick-shell or "giant" core/shell nanocrystal quantum dots (gQDs) are efficient and stable emitters. Their characteristic properties of non-blinking and non-photobleaching emission, as well as suppressed non-radiative Auger recombination and minimal self-reabsorption (due to a large effective Stokes shift) make them relevant to both single-emitter and many-emitter applications, e.g., live-cell single-molecule tracking in the biosciences and down-conversion phosphors for solid-state lighting. Here, I will discuss how gQDs are also ideal "building blocks" for achieving additive functionalities through synthesis and modified emission properties through integration with fabricated photonic structures. gQDs have been synthetically incorporated into the interior of a gold shell, resulting in "plasmonic gQDs" that exhibit efficient photoluminescence combined with efficient photothermal transduction and thermometry. Furthermore, through direct patterning of gQDs into all-dielectric antennas, we show an approach for realizing emitter-antenna couples (toward controlling the motion of photons) that is both deterministic and reproducible.
Benelli, Giovanni
2014-01-01
True fruit flies (Diptera: Tephritidae) include over 4000 species, many of which constitute enormous threats to fruit and vegetable production worldwide. A number of Tephritidae are lekking species, forming aggregations in which males fight to defend a small territory where they court females and mate. Male-male contests also occur in non-lekking species, characterized by resource defense polygyny. Tephritidae females display agonistic behavior to maintain single oviposition sites and reduce larval competition for food. Here, how, where, when and why aggressive interactions occur in Tephritidae flies is reviewed. A number of neglected issues deserving further research are highlighted, with a special focus on diel periodicity of aggression, cues evoking aggressive behavior, the role of previous experience on fighting success and the evolution of behavioral lateralization of aggressive displays. In the final section, future directions to exploit this knowledge in Integrated Pest Management, with particular emphasis on enhancement of Sterile Insect Technique and interspecific competitive displacement in the field are suggested. PMID:26463064
Kang, Da-Young; Kim, Cheolho; Park, Gyurim; Moon, Jun Hyuk
2015-01-01
The direct pyrolytic carbonisation of polymer patterns has attracted interest for its use in obtaining carbon materials. In the case of carbonisation of nanopatterned polymers, the polymer flow and subsequent pattern change may occur in order to relieve their high surface energies. Here, we demonstrated that liquid immersion thermal crosslinking of polymer nanopatterns effectively enhanced the thermal resistance and maintained the structure integrity during the heat treatment. We employed the liquid immersion thermal crosslinking for 3D porous SU8 photoresist nanopatterns and successfully converted them to carbon nanopatterns while maintaining their porous features. The thermal crosslinking reaction and carbonisation of SU8 nanopatterns were characterised. The micro-crystallinity of the SU8-derived carbon nanopatterns was also characterised. The liquid immersion heat treatment can be extended to the carbonisation of various polymer or photoresist nanopatterns and also provide a facile way to control the surface energy of polymer nanopatterns for various purposes, for example, to block copolymer or surfactant self-assemblies. PMID:26677949
NASA Astrophysics Data System (ADS)
Kang, Da-Young; Kim, Cheolho; Park, Gyurim; Moon, Jun Hyuk
2015-12-01
The direct pyrolytic carbonisation of polymer patterns has attracted interest for its use in obtaining carbon materials. In the case of carbonisation of nanopatterned polymers, the polymer flow and subsequent pattern change may occur in order to relieve their high surface energies. Here, we demonstrated that liquid immersion thermal crosslinking of polymer nanopatterns effectively enhanced the thermal resistance and maintained the structure integrity during the heat treatment. We employed the liquid immersion thermal crosslinking for 3D porous SU8 photoresist nanopatterns and successfully converted them to carbon nanopatterns while maintaining their porous features. The thermal crosslinking reaction and carbonisation of SU8 nanopatterns were characterised. The micro-crystallinity of the SU8-derived carbon nanopatterns was also characterised. The liquid immersion heat treatment can be extended to the carbonisation of various polymer or photoresist nanopatterns and also provide a facile way to control the surface energy of polymer nanopatterns for various purposes, for example, to block copolymer or surfactant self-assemblies.
Zhang, Kaixiang; Kang, Dong-Ku; Ali, M Monsur; Liu, Linan; Labanieh, Louai; Lu, Mengrou; Riazifar, Hamidreza; Nguyen, Thi N; Zell, Jason A; Digman, Michelle A; Gratton, Enrico; Li, Jinghong; Zhao, Weian
2015-11-01
Quantification of miRNAs in blood can be potentially used for early disease detection, surveillance monitoring and drug response evaluation. However, quantitative and robust measurement of miRNAs in blood is still a major challenge in large part due to their low concentration and complicated sample preparation processes typically required in conventional assays. Here, we present the 'Integrated Comprehensive Droplet Digital Detection' (IC 3D) system where the plasma sample containing target miRNAs is encapsulated into microdroplets, enzymatically amplified and digitally counted using a novel, high-throughput 3D particle counter. Using Let-7a as a target, we demonstrate that IC 3D can specifically quantify target miRNA directly from blood plasma at extremely low concentrations ranging from 10s to 10 000 copies per mL in ≤3 hours without the need for sample processing such as RNA extraction. Using this new tool, we demonstrate that target miRNA content in colon cancer patient blood is significantly higher than that in healthy donor samples. Our IC 3D system has the potential to introduce a new paradigm for rapid, sensitive and specific detection of low-abundance biomarkers in biological samples with minimal sample processing. PMID:26387763
Ravindra, M.K.; Banon, H. )
1992-07-01
In this report, the scoping quantification procedures for external events in probabilistic risk assessments of nuclear power plants are described. External event analysis in a PRA has three important goals; (1) the analysis should be complete in that all events are considered; (2) by following some selected screening criteria, the more significant events are identified for detailed analysis; (3) the selected events are analyzed in depth by taking into account the unique features of the events: hazard, fragility of structures and equipment, external-event initiated accident sequences, etc. Based on the above goals, external event analysis may be considered as a three-stage process: Stage I: Identification and Initial Screening of External Events; Stage II: Bounding Analysis; Stage III: Detailed Risk Analysis. In the present report, first, a review of published PRAs is given to focus on the significance and treatment of external events in full-scope PRAs. Except for seismic, flooding, fire, and extreme wind events, the contributions of other external events to plant risk have been found to be negligible. Second, scoping methods for external events not covered in detail in the NRC's PRA Procedures Guide are provided. For this purpose, bounding analyses for transportation accidents, extreme winds and tornadoes, aircraft impacts, turbine missiles, and chemical release are described.
Ravindra, M.K.; Banon, H.
1992-07-01
In this report, the scoping quantification procedures for external events in probabilistic risk assessments of nuclear power plants are described. External event analysis in a PRA has three important goals; (1) the analysis should be complete in that all events are considered; (2) by following some selected screening criteria, the more significant events are identified for detailed analysis; (3) the selected events are analyzed in depth by taking into account the unique features of the events: hazard, fragility of structures and equipment, external-event initiated accident sequences, etc. Based on the above goals, external event analysis may be considered as a three-stage process: Stage I: Identification and Initial Screening of External Events; Stage II: Bounding Analysis; Stage III: Detailed Risk Analysis. In the present report, first, a review of published PRAs is given to focus on the significance and treatment of external events in full-scope PRAs. Except for seismic, flooding, fire, and extreme wind events, the contributions of other external events to plant risk have been found to be negligible. Second, scoping methods for external events not covered in detail in the NRC`s PRA Procedures Guide are provided. For this purpose, bounding analyses for transportation accidents, extreme winds and tornadoes, aircraft impacts, turbine missiles, and chemical release are described.
Robust control methods for nonlinear systems with uncertain dynamics and unknown control direction
NASA Astrophysics Data System (ADS)
Ton, Chau T.
Robust nonlinear control design strategies using sliding mode control (SMC) and integral SMC (ISMC) are developed, which are capable of achieving reliable and accurate tracking control for systems containing dynamic uncertainty, unmodeled disturbances, and actuator anomalies that result in an unknown and time-varying control direction. In order to ease readability of this dissertation, detailed explanations of the relevant mathematical tools is provided, including stability denitions, Lyapunov-based stability analysis methods, SMC and ISMC fundamentals, and other basic nonlinear control tools. The contributions of the dissertation are three novel control algorithms for three different classes of nonlinear systems: single-input multipleoutput (SIMO) systems, systems with model uncertainty and bounded disturbances, and systems with unknown control direction. Control design for SIMO systems is challenging due to the fact that such systems have fewer actuators than degrees of freedom to control (i.e., they are underactuated systems). While traditional nonlinear control methods can be utilized to design controllers for certain classes of cascaded underactuated systems, more advanced methods are required to develop controllers for parallel systems, which are not in a cascade structure. A novel control technique is proposed in this dissertation, which is shown to achieve asymptotic tracking for dual parallel systems, where a single scalar control input directly aects two subsystems. The result is achieved through an innovative sequential control design algorithm, whereby one of the subsystems is indirectly stabilized via the desired state trajectory that is commanded to the other subsystem. The SIMO system under consideration does not contain uncertainty or disturbances. In dealing with systems containing uncertainty in the dynamic model, a particularly challenging situation occurs when uncertainty exists in the input-multiplicative gain matrix. Moreover, special
NASA Technical Reports Server (NTRS)
Goorjian, Peter M.; Taflove, Allen
1992-01-01
The initial results for femtosecond electromagnetic soliton propagation and collision obtained from first principles, i.e., by a direct time integration of Maxwell's equations are reported. The time integration efficiently implements linear and nonlinear convolutions for the electric polarization and can take into account such quantum effects as Kerr and Raman interactions. The present approach is robust and should permit the modeling of 2D and 3D optical soliton propagation, scattering, and switching from the full-vector Maxwell's equations.
NASA Astrophysics Data System (ADS)
Tanaka, Satoyuki; Suzuki, Hirotaka; Sadamoto, Shota; Sannomaru, Shogo; Yu, Tiantang; Bui, Tinh Quoc
2016-08-01
Two-dimensional (2D) in-plane mixed-mode fracture mechanics problems are analyzed employing an efficient meshfree Galerkin method based on stabilized conforming nodal integration (SCNI). In this setting, the reproducing kernel function as meshfree interpolant is taken, while employing the SCNI for numerical integration of stiffness matrix in the Galerkin formulation. The strain components are smoothed and stabilized employing Gauss divergence theorem. The path-independent integral ( J-integral) is solved based on the nodal integration by summing the smoothed physical quantities and the segments of the contour integrals. In addition, mixed-mode stress intensity factors (SIFs) are extracted from the J-integral by decomposing the displacement and stress fields into symmetric and antisymmetric parts. The advantages and features of the present formulation and discretization in evaluation of the J-integral of in-plane 2D fracture problems are demonstrated through several representative numerical examples. The mixed-mode SIFs are evaluated and compared with reference solutions. The obtained results reveal high accuracy and good performance of the proposed meshfree method in the analysis of 2D fracture problems.
Wunschel, David S.; Melville, Angela M.; Ehrhardt, Christopher J.; Colburn, Heather A.; Victry, Kristin D.; Antolick, Kathryn C.; Wahl, Jon H.; Wahl, Karen L.
2012-05-17
The investigation of crimes involving chemical or biological agents is infrequent, but presents unique analytical challenges. The protein toxin ricin is encountered more frequently than other agents and is found in the seeds of the castor plant Ricinus communis. Typically, the toxin is extracted from castor seeds utilizing a variety of different recipes that result in varying purity of the toxin. Moreover, these various purification steps can also leave or differentially remove a variety of exogenous and endogenous residual components with the toxin that may indicate the type and number of purification steps involved. We have applied three gas chromatographic - mass spectrometric (GC-MS) based analytical methods to measure the variation in seed carbohydrates and castor oil ricinoleic acid as well as the presence of solvents used for purification. These methods were applied to the same samples prepared using four previously identified toxin preparation methods starting from four varieties of castor seeds. The individual data sets for seed carbohydrate profiles, ricinoleic acid or acetone amount each provided information capable of differentiating different types of toxin preparations across seed types. However, the integration of the data sets using multivariate factor analysis provided a clear distinction of all samples based on the preparation method and independent of the seed source. In particular the abundance of mannose, arabinose, fucose, ricinoleic acid and acetone were shown to be important differentiating factors. These complementary tools provide a more confident determination of the method of toxin preparation.
Darrell P. Chandler; Ann E. Jarrell; Craig S. Criddle
2004-03-17
Molecular methods are still relatively ineffectual for monitoring community dynamics during bioremediation, due primarily to the cost, technical difficulty and retrospective nature of the analyses. For nucleic acid analyses to meaningfully contribute to bioremediation efforts they must not only contribute to the fundamental understanding of microbial ecology, but also be formatted in such a manner that infield analysis can be achieved. The objective of this project is therefore to develop an integrated microbial and nucleic acid detection method and prototype system for the characterization and analysis of subsurface sediments, focusing on the molecular detection of metal and sulfate-reducing bacteria and activity in sediments obtained from the Oak Ridge Field Research Center. We are meeting this objective by combining environmental molecular microbiology with renewable surface techniques, microfluidic systems and microparticle analytical chemistry. The fluidic systems are used to evaluate hypotheses on the integrated biochemistry that is necessary to directly detect 16S rRNA from metal-reducing microbial communities on a suspension microarray, without using the polymerase chain reaction (PCR). These investigations include the use of peptide nucleic acid capture and detection probes and 'tunable surface' concepts to increase nucleic acid capture and detection efficiency and/or mitigate interferences due to co-extracted humic acids. The unified microparticle sample preparation method and suspension array is then used to characterize the 16S rRNA metal- and sulfate-reducing microbial community in FRC sediments before and after biostimulation.
Integration of a molten carbonate fuel cell with a direct exhaust absorption chiller
NASA Astrophysics Data System (ADS)
Margalef, Pere; Samuelsen, Scott
A high market value exists for an integrated high-temperature fuel cell-absorption chiller product throughout the world. While high-temperature, molten carbonate fuel cells are being commercially deployed with combined heat and power (CHP) and absorption chillers are being commercially deployed with heat engines, the energy efficiency and environmental attributes of an integrated high-temperature fuel cell-absorption chiller product are singularly attractive for the emerging distributed generation (DG) combined cooling, heating, and power (CCHP) market. This study addresses the potential of cooling production by recovering and porting the thermal energy from the exhaust gas of a high-temperature fuel cell (HTFC) to a thermally activated absorption chiller. To assess the practical opportunity of serving an early DG-CCHP market, a commercially available direct fired double-effect absorption chiller is selected that closely matches the exhaust flow and temperature of a commercially available HTFC. Both components are individually modeled, and the models are then coupled to evaluate the potential of a DG-CCHP system. Simulation results show that a commercial molten carbonate fuel cell generating 300 kW of electricity can be effectively coupled with a commercial 40 refrigeration ton (RT) absorption chiller. While the match between the two "off the shelf" units is close and the simulation results are encouraging, the match is not ideal. In particular, the fuel cell exhaust gas temperature is higher than the inlet temperature specified for the chiller and the exhaust flow rate is not sufficient to achieve the potential heat recovery within the chiller heat exchanger. To address these challenges, the study evaluates two strategies: (1) blending the fuel cell exhaust gas with ambient air, and (2) mixing the fuel cell exhaust gases with a fraction of the chiller exhaust gas. Both cases are shown to be viable and result in a temperature drop and flow rate increase of the
NASA Astrophysics Data System (ADS)
Tsalamengas, John L.
2015-12-01
We present n-point Gauss-Gegenbauer quadrature rules for weakly singular, strongly singular, and hypersingular integrals that arise in integral equation formulations of potential problems in domains with edges and corners. The rules are tailored to weight functions with algebraic endpoint singularities related to the geometrical singularities of the domain. Each rule has two different expressions involving Legendre functions and hypergeometric functions, respectively. Numerical examples amply demonstrate the accuracy and stability of the proposed algorithms. Application to the solution of a singular integral equation is exemplified.
Apparatus and Method for Packaging and Integrating Microphotonic Devices
NASA Technical Reports Server (NTRS)
Nguyen, Hung (Inventor)
2008-01-01
An apparatus is disclosed that includes a carrier structure and an optical coupling arrangement. The carrier structure is made of a silicon material and allows for the packaging and integrating of microphotonic devices onto a single chip. The optical coupling mechanism enables laser light to be coupled into and out of a microphotonic resonant disk integrated on the carrier. The carrier provides first, second and third cavities that are dimensioned so as to accommodate the insertion and snug fitting of the microphotonic resonant disk and first and second prisms that are implemented by the optical coupling arrangement to accommodate the laser coupling.
Mill Integration-Pulping, Stream Reforming and Direct Causticization for Black Liquor Recovery
Adriaan van Heiningen
2007-06-30
MTCI/StoneChem developed a steam reforming, fluidized bed gasification technology for biomass. DOE supported the demonstration of this technology for gasification of spent wood pulping liquor (or 'black liquor') at Georgia-Pacific's Big Island, Virginia mill. The present pre-commercial R&D project addressed the opportunities as well as identified negative aspects when the MTCI/StoneChem gasification technology is integrated in a pulp mill production facility. The opportunities arise because black liquor gasification produces sulfur (as H{sub 2}S) and sodium (as Na{sub 2}CO{sub 3}) in separate streams which may be used beneficially for improved pulp yield and properties. The negative aspect of kraft black liquor gasification is that the amount of Na{sub 2}CO{sub 3} which must be converted to NaOH (the so called causticizing requirement) is increased. This arises because sulfur is released as Na{sub 2}S during conventional kraft black liquor recovery, while during gasification the sodium associated Na{sub 2}S is partly or fully converted to Na{sub 2}CO{sub 3}. The causticizing requirement can be eliminated by including a TiO{sub 2} based cyclic process called direct causticization. In this process black liquor is gasified in the presence of (low sodium content) titanates which convert Na{sub 2}CO{sub 3} to (high sodium content) titanates. NaOH is formed when contacting the latter titanates with water, thereby eliminating the causticizing requirement entirely. The leached and low sodium titanates are returned to the gasification process. The project team comprised the University of Maine (UM), North Carolina State University (NCSU) and MTCI/ThermoChem. NCSU and MTCI are subcontractors to UM. The principal organization for the contract is UM. NCSU investigated the techno-economics of using advanced pulping techniques which fully utilize the unique cooking liquors produced by steam reforming of black liquor (Task 1). UM studied the kinetics and agglomeration problems of
The need for integration in health sciences sets the future direction for public health education.
Li, L M; Tang, J L; Lv, J; Jiang, Y; Griffiths, S M
2011-01-01
Since the foundation of the People's Republic of China in 1949, there has been remarkable developments in public health in the country. These achievements are primarily attributed to the public health services and patriotic public health campaigns, although the contribution of high-technology medical applications is also recognized. However, along with the recent socio-economic developments and scientific and technological progress, medical disciplines have become more and more specialized, and clinical and preventive medicine have become further separated from each other. Conventional Chinese wisdom says 'when long divided they must unite, when long united they must divide'. At the onset of the new round of reforms of health care in China, it seems important to revisit the discussions on the urgency for integration of health sciences in medicine in China. Several issues and viewpoints on integrating medicine are discussed in this paper. The biopsychosocial model for health calls for broad integration. Primary care development in China requires integration in education and practice, and in treatment and prevention. Control of chronic diseases requires integrated and united action. Integration of traditional Chinese medicine with Western medicine requires creativity. The integration perspective should be instilled in the minds of medical students. Integration also entails integrated practice. After all, integration entails integrated education and practice in public health education. Changing the current public health education system still has a long way to go. True integration requires integration of concepts, policies, resources and measures, as well as changes in the organization of health care including public health, prevention and treatment. This needs to be a systematic process. Finally, success of integration relies on social mobilization, advocacy, promotion and attention of the entire society. PMID:21168177
Georgiou, Fotis; Hornikx, Maarten
2016-08-01
The pseudospectral time-domain method (PSTD) provides an efficient way to solve the linear acoustics equations. With regards to acoustic modeling and auralization, source directivity as well as head-related directivity have a clear influence on the perceived sound field and have to be included in computations. In this paper directive sources are implemented in the time-domain method PSTD. First, a given frequency dependent source directivity is decomposed onto spherical harmonic functions. The directive source is then implemented through spatial distributions in PSTD that relate to the spherical harmonic functions, and time-dependent functions are assigned to the spatial distributions in order to obtain the frequency content of the directivity. Since any directivity function can be expressed as a summation of series of spherical harmonics, the approach can be used to model any type of directive source. For the evaluation of the method, a directivity function was designed analytically and then modeled in PSTD. Octave band analysis was performed and results show a good agreement between the analytical and simulated directivity. A distance related error was observed. However, for distances above 17.5 grid cells from the source center the average error was small (<0.9 dB) at all octave-bands. PMID:27586717
Reconfigurable, Bi-Directional Flexfet Level Shifter for Low-Power, Rad-Hard Integration
NASA Technical Reports Server (NTRS)
DeGregorio, Kelly; Wilson, Dale G.
2009-01-01
Two prototype Reconfigurable, Bi-directional Flexfet Level Shifters (ReBiLS) have been developed, where one version is a stand-alone component designed to interface between external low voltage and high voltage, and the other version is an embedded integrated circuit (IC) for interface between internal low-voltage logic and external high-voltage components. Targeting stand-alone and embedded circuits separately allows optimization for these distinct applications. Both ReBiLS designs use the commercially available 180-nm Flex fet Independently Double-Gated (IDG) SOI CMOS (silicon on insulator, complementary metal oxide semiconductor) technology. Embedded ReBiLS circuits were integrated with a Reed-Solomon (RS) encoder using CMOS Ultra-Low-Power Radiation Tolerant (CULPRiT) double-gated digital logic circuits. The scope of the project includes: creation of a new high-voltage process, development of ReBiLS circuit designs, and adjustment of the designs to maximize performance through simulation, layout, and manufacture of prototypes. The primary technical objectives were to develop a high-voltage, thick oxide option for the 180-nm Flexfet process, and to develop a stand-alone ReBiLS IC with two 8-channel I/O busses, 1.8 2.5 I/O on the low-voltage pins, 5.0-V-tolerant input and 3.3-V output I/O on the high-voltage pins, and 100-MHz minimum operation with 10-pF external loads. Another objective was to develop an embedded, rad-hard ReBiLS I/O cell with 0.5-V low-voltage operation for interface with core logic, 5.0-V-tolerant input and 3.3-V output I/O pins, and 100-MHz minimum operation with 10- pF external loads. A third objective was to develop a 0.5- V Reed-Solomon Encoder with embedded ReBilS I/O: Transfer the existing CULPRiT RS encoder from a 0.35-micron bulk-CMOS process to the ASI 180-nm Flexfet, rad-hard SOI Process. 0.5-V low-voltage core logic. 5.0-V-tolerant input and 3.3-V output I/O pins. 100-MHz minimum operation with 10- pF external loads. The stand
ERIC Educational Resources Information Center
Jang, Eunice E.; McDougall, Douglas E.; Pollon, Dawn; Herbert, Monique; Russell, Pia
2008-01-01
There are both conceptual and practical challenges in dealing with data from mixed methods research studies. There is a need for discussion about various integrative strategies for mixed methods data analyses. This article illustrates integrative analytic strategies for a mixed methods study focusing on improving urban schools facing challenging…
Array-representation Integration Factor Method for High-dimensional Systems
Wang, Dongyong; Zhang, Lei; Nie, Qing
2013-01-01
High order spatial derivatives and stiff reactions often introduce severe temporal stability constraints on the time step in numerical methods. Implicit integration method (IIF) method, which treats diffusion exactly and reaction implicitly, provides excellent stability properties with good efficiency by decoupling the treatment of reactions and diffusions. One major challenge for IIF is storage and calculation of the potential dense exponential matrices of the sparse discretization matrices resulted from the linear differential operators. Motivated by a compact representation for IIF (cIIF) for Laplacian operators in two and three dimensions, we introduce an array-representation technique for efficient handling of exponential matrices from a general linear differential operator that may include cross-derivatives and non-constant diffusion coefficients. In this approach, exponentials are only needed for matrices of small size that depend only on the order of derivatives and number of discretization points, independent of the size of spatial dimensions. This method is particularly advantageous for high dimensional systems, and it can be easily incorporated with IIF to preserve the excellent stability of IIF. Implementation and direct simulations of the array-representation compact IIF (AcIIF) on systems, such as Fokker-Planck equations in three and four dimensions and chemical master equations, in addition to reaction-diffusion equations, show efficiency, accuracy, and robustness of the new method. Such array-presentation based on methods may have broad applications for simulating other complex systems involving high-dimensional data. PMID:24415797
NASA Astrophysics Data System (ADS)
Walsh, Jonathan A.; Forget, Benoit; Smith, Kord S.; Brown, Forrest B.
2016-03-01
In this work we describe the development and application of computational methods for processing neutron cross section data in the unresolved resonance region (URR). These methods are integrated with a continuous-energy Monte Carlo neutron transport code, thereby enabling their use in high-fidelity analyses. Enhanced understanding of the effects of URR evaluation representations on calculated results is then obtained through utilization of the methods in Monte Carlo integral benchmark simulations of fast spectrum critical assemblies. First, we present a so-called on-the-fly (OTF) method for calculating and Doppler broadening URR cross sections. This method proceeds directly from ENDF-6 average unresolved resonance parameters and, thus, eliminates any need for a probability table generation pre-processing step in which tables are constructed at several energies for all desired temperatures. Significant memory reduction may be realized with the OTF method relative to a probability table treatment if many temperatures are needed. Next, we examine the effects of using a multi-level resonance formalism for resonance reconstruction in the URR. A comparison of results obtained by using the same stochastically-generated realization of resonance parameters in both the single-level Breit-Wigner (SLBW) and multi-level Breit-Wigner (MLBW) formalisms allows for the quantification of level-level interference effects on integrated tallies such as keff and energy group reaction rates. Though, as is well-known, cross section values at any given incident energy may differ significantly between single-level and multi-level formulations, the observed effects on integral results are minimal in this investigation. Finally, we demonstrate the calculation of true expected values, and the statistical spread of those values, through independent Monte Carlo simulations, each using an independent realization of URR cross section structure throughout. It is observed that both probability table
Integration of smart materials into high-volume manufacturing methods
NASA Astrophysics Data System (ADS)
Bianchini, Emanuele
2006-03-01
The integration of smart materials such as piezoelectric devices and shape memory alloys into structures has been typically limited to a bonding process that occurs as a secondary operation. Such an operation is not only costly for high volume applications but also has the potential of degrading the performance of the actuator or sensor due to the bonding agent selected. The work presented here explores the integration of piezoelectric materials using a high volume injection molding process. The process used is typical for large automotive components such as bumpers, instrument panels and other body panels. Different materials were evaluated, including plastics and both bare and packaged smart materials. Temperature and flow rate were also changed to investigate the effects on the durability of the materials. Both electrical and mechanical properties were tested with the key parameters including, void content, shifting from initial position, strain transfer and peal strength. It was found that good integration of piezoelectric materials could be achieved and electro-mechanical properties were improved as compared to a secondary bonding operation. Integration of screen-printed electrical circuits for electrical connectivity for piezoelectric materials will be evaluated in future research. In conclusion, a step forward was made in developing a multifunctional material based upon smart materials and conventional high volume manufacturing processes.
Integral reactor system and method for fuel cells
Fernandes, Neil Edward; Brown, Michael S; Cheekatamarla, Praveen; Deng, Thomas; Dimitrakopoulos, James; Litka, Anthony F
2013-11-19
A reactor system is integrated internally within an anode-side cavity of a fuel cell. The reactor system is configured to convert hydrocarbons to smaller species while mitigating the lower production of solid carbon. The reactor system may incorporate one or more of a pre-reforming section, an anode exhaust gas recirculation device, and a reforming section.
Adventure Programming and Spirituality: Integration Models, Methods, and Research.
ERIC Educational Resources Information Center
Anderson-Hanley, Cay
1997-01-01
Reviews the literature on the relationship of adventure education and experiential learning to spiritual experiences and development. Discusses definitions of spirituality, religion, and related terms; two frameworks for integration of psychology and spirituality and their application to experiential education; specific strategies for integrating…
Detection of magnetising inrush current using real time integration method
NASA Astrophysics Data System (ADS)
Ling, P. C. Y.; Basak, A.
1990-01-01
A technique of predicting magnetising inrush currents in transformers is described. Computed results show an inconsistency in second harmonic decay resulting detection failure while using conventional second harmonic techniques. A new detection scheme using real time integration values of the inrush current is proposed to provide reliable relay operation.
METHODS FOR INTEGRATING ENVIRONMENTAL CONSIDERATIONS INTO CHEMICAL PROCESS DESIGN DECISIONS
The objective of this cooperative agreement was to postulate a means by which an engineer could routinely include environmental considerations in day-to-day conceptual design problems; a means that could easily integrate with existing design processes, and thus avoid massive retr...
Integrated Instruction in University Methods Courses: Applying Science Technology Society.
ERIC Educational Resources Information Center
King, Kenneth P.; Milson, Andrew J.
The science-technology-society (STS) movement represents an attempt to "liberate the student from narrow utilities" (Dewey) through an interdisciplinary approach to the three content areas (science, technology, and society) providing a coherent conceptual scheme for integrating classroom instruction. This action research study sought to identify…
Bioluminescent bioreporter integrated circuit devices and methods for detecting ammonia
Simpson, Michael L [Knoxville, TN; Paulus, Michael J [Knoxville, TN; Sayler, Gary S [Blaine, TN; Applegate, Bruce M [West Lafayette, IN; Ripp, Steven A [Knoxville, TN
2007-04-24
Monolithic bioelectronic devices for the detection of ammonia includes a microorganism that metabolizes ammonia and which harbors a lux gene fused with a heterologous promoter gene stably incorporated into the chromosome of the microorganism and an Optical Application Specific Integrated Circuit (OASIC). The microorganism is generally a bacterium.
NASA Astrophysics Data System (ADS)
Zhou, Jian; Yang, Daquan; Tian, Huiping; Huang, Lijun; Zhang, Pan; Ji, Yuefeng
2015-06-01
In the previous work [1], we have proposed a method to realize multi-directional pressure sensor. This follow-up work provides an optimized structure design based on the integration of double 60° bend waveguides and modified center-defect photonic crystal microcavity to further improve sensitivity. By applying two-dimensional finite difference time domain technologies (2D-FDTD) and finite-element methods (FEM), we systematically investigate the variations of optical properties under applied pressure. Linear relationships between the resonant wavelength shift and the applied pressure are obtained in three directions. The ultra-high sensitivities and the low minimum detectable pressure in longitudinal, transverse and upright directions are 39.7 nm/μN and 1.08 nN, 30.20 nm/μN and 1.43 nN, and 0.12 nm/nN and 0.36 nN respectively.
NASA Astrophysics Data System (ADS)
Rapaka, Narsimha R.; Sarkar, Sutanu
2016-10-01
A sharp-interface Immersed Boundary Method (IBM) is developed to simulate density-stratified turbulent flows in complex geometry using a Cartesian grid. The basic numerical scheme corresponds to a central second-order finite difference method, third-order Runge-Kutta integration in time for the advective terms and an alternating direction implicit (ADI) scheme for the viscous and diffusive terms. The solver developed here allows for both direct numerical simulation (DNS) and large eddy simulation (LES) approaches. Methods to enhance the mass conservation and numerical stability of the solver to simulate high Reynolds number flows are discussed. Convergence with second-order accuracy is demonstrated in flow past a cylinder. The solver is validated against past laboratory and numerical results in flow past a sphere, and in channel flow with and without stratification. Since topographically generated internal waves are believed to result in a substantial fraction of turbulent mixing in the ocean, we are motivated to examine oscillating tidal flow over a triangular obstacle to assess the ability of this computational model to represent nonlinear internal waves and turbulence. Results in laboratory-scale (order of few meters) simulations show that the wave energy flux, mean flow properties and turbulent kinetic energy agree well with our previous results obtained using a body-fitted grid (BFG). The deviation of IBM results from BFG results is found to increase with increasing nonlinearity in the wave field that is associated with either increasing steepness of the topography relative to the internal wave propagation angle or with the amplitude of the oscillatory forcing. LES is performed on a large scale ridge, of the order of few kilometers in length, that has the same geometrical shape and same non-dimensional values for the governing flow and environmental parameters as the laboratory-scale topography, but significantly larger Reynolds number. A non-linear drag law
NASA Astrophysics Data System (ADS)
Olejarczyk, Elzbieta; Kaminski, Maciej; Marciniak, Radoslaw; Byrczek, Tomasz; Stasiowski, Michal; Jalowiecki, Przemyslaw; Sobieszek, Aleksander; Zmyslowski, Wojciech
2011-01-01
The aim of this study was to estimate spectral properties and propagation of the EEG signals registered during sevoflurane anaesthesia between individual EEG recording channels. The intensities of activity flows were calculated for delta, theta, alpha and beta waves using the Directed Transfer Function integration procedure. It was found that delta waves played the dominant role in the EEG signal propagation during anesthesia and it was suggested that theta and alpha waves propagation could be related to the processes participating in the wakefulness control. Data obtained with DTF method were compared with data received from the analysis of cerebral blood flow with the use of PET in other laboratory. This study showed that analysis of the EEG signal propagation is useful for better understanding and thus safer induction of anaesthesia procedure.
Evaluation of Direct Aqueous Injection Method for Analysis of Chloroform in Drinking Water
ERIC Educational Resources Information Center
Pfaender, Frederic K.; And Others
1978-01-01
A direct aqueous injection (DAI) technique was compared with the purge method for chloroform measurement in drinking water. The DAI method gave consistently higher values for chloroform than the purge method. The results indicated the need for caution in the interpretation of chloroform and other trihalomethane values generated by DAI. (Author/MA)
Zhou, Shiyuan Sun, Haoyu Xu, Chunguang Cao, Xiandong Cui, Liming Xiao, Dingguo
2015-03-31
The echo signal energy is directly affected by the incident sound beam eccentricity or angle for thick-walled pipes inner longitudinal cracks detection. A method for analyzing the relationship between echo signal energy between the values of incident eccentricity is brought forward, which can be used to estimate echo signal energy when testing inside wall longitudinal crack of pipe, using mode-transformed compression wave adaptation of shear wave with water-immersion method, by making a two-dimension integration of “energy coefficient” in both circumferential and axial directions. The calculation model is founded for cylinder sound beam case, in which the refraction and reflection energy coefficients of different rays in the whole sound beam are considered different. The echo signal energy is calculated for a particular cylinder sound beam testing different pipes: a beam with a diameter of 0.5 inch (12.7mm) testing a φ279.4mm pipe and a φ79.4mm one. As a comparison, both the results of two-dimension integration and one-dimension (circumferential direction) integration are listed, and only the former agrees well with experimental results. The estimation method proves to be valid and shows that the usual method of simplifying the sound beam as a single ray for estimating echo signal energy and choosing optimal incident eccentricity is not so appropriate.
Testa, Maria; Livingston, Jennifer A.; VanZile-Tamsen, Carol
2011-01-01
A mixed methods approach, combining quantitative with qualitative data methods and analysis, offers a promising means of advancing the study of violence. Integrating semi-structured interviews and qualitative analysis into a quantitative program of research on women’s sexual victimization has resulted in valuable scientific insight and generation of novel hypotheses for testing. This mixed methods approach is described and recommendations for integrating qualitative data into quantitative research are provided. PMID:21307032
Testa, Maria; Livingston, Jennifer A; VanZile-Tamsen, Carol
2011-02-01
A mixed methods approach, combining quantitative with qualitative data methods and analysis, offers a promising means of advancing the study of violence. Integrating semi-structured interviews and qualitative analysis into a quantitative program of research on women's sexual victimization has resulted in valuable scientific insight and generation of novel hypotheses for testing. This mixed methods approach is described and recommendations for integrating qualitative data into quantitative research are provided.
NASA Astrophysics Data System (ADS)
Salamon, Z.; Hazzard, J. T.; Tollin, G.
1993-07-01
Direct cyclic voltage-current responses, produced in the absence of redox mediators, for two detergent-solubilized integral membrane proteins, spinach cytochrome f and beef heart cytochrome c oxidase, have been obtained at an optically transparent indium oxide electrode modified with a self-assembled lipid-bilayer membrane. The results indicate that both proteins interact with the lipid membrane so as to support quasi-reversible electron transfer redox reactions at the semiconductor electrode. The redox potentials that were obtained from analysis of the cyclic "voltammograms," 365 mV for cytochrome f and 250 and 380 mV for cytochrome c oxidase (vs. normal hydrogen electrode), compare quite well with the values reported by using conventional titration methods. The ability to obtain direct electrochemical measurements opens up another approach to the investigation of the properties of integral membrane redox proteins.
Salamon, Z.; Hazzard, J.T.; Tollin, G. )
1993-07-15
Direct cyclic voltage-current responses, produced in the absence of redox mediators, for two detergent-solubilized integral membrane proteins, spinach cytochrome f and beef heart cytochrome c oxidase, have been obtained at an optically transparent indium oxide electrode modified with a self-assembled lipid-bilayer membrane. The results indicate that both proteins interact with the lipid membrane so as to support quasi-reversible electron transfer redox reactions at the semiconductor electrode. The redox potentials that were obtained from analysis of the cyclic [open quotes]voltammograms,[close quotes] 365 mV for cytochrome f and 250 and 380 mV for cytochrome c oxidase (vs. normal hydrogen electrode), compare quite well with the values reported by using conventional titration methods. The ability to obtain direct electrochemical measurements opens up another approach to the investigation of the properties of integral membrane redox proteins. 63 refs., 2 figs., 1 tab.
NASA Astrophysics Data System (ADS)
Frey, O.; van der Wal, P. D.; Spieth, S.; Brett, O.; Seidl, K.; Paul, O.; Ruther, P.; Zengerle, R.; de Rooij, N. F.
2011-10-01
This paper reports on silicon-based microprobes, 8 mm long and 250 µm × 250 µm cross-section, comprising four recessed biosensor microelectrodes (50 µm × 150 µm) per probe shank coated with an enzymatic layer for the selective detection of choline at multiple sites in brain tissue. Integrated in the same probe shank are up to two microfluidic channels for controlled local liquid delivery at a defined distance from the biosensor microelectrodes. State-of-the-art silicon micromachining processing was applied for reproducible fabrication of these experiment-tailored multi-functional probe arrays. Reliable electric and fluidic interconnections to the microprobes are guaranteed by a custom-made holder. The reversible packaging method implemented in this holder significantly reduces cost and assembly time and simplifies storage of the biosensor probes between consecutive experiments. The functionalization of the electrodes is carried out using electrochemically aided adsorption. This spatially controlled deposition technique enables a parallel deposition of membranes and is especially useful when working with microelectrode arrays. The achieved biosensors show adequate characteristics to detect choline in physiologically relevant concentrations at sufficient temporal and spatial resolution for brain research. Sensitivity to choline better than 10 pA µm-1, detection limit below 1 µM and response time of 2 s were obtained. The proposed combination of biosensors and microfluidic injectors on the same microprobe allows simultaneous chemical stimulation and recording as demonstrated in an agarose gel-based brain phantom.
Martínez-Mier, E. Angeles; Soto-Rojas, Armando E.; Buckley, Christine M.; Margineda, Jorge; Zero, Domenick T.
2010-01-01
Objective The aim of this study was to assess methods currently used for analyzing fluoridated salt in order to identify the most useful method for this type of analysis. Basic research design Seventy-five fluoridated salt samples were obtained. Samples were analyzed for fluoride content, with and without pretreatment, using direct and diffusion methods. Element analysis was also conducted in selected samples. Fluoride was added to ultra pure NaCl and non-fluoridated commercial salt samples and Ca and Mg were added to fluoride samples in order to assess fluoride recoveries using modifications to the methods. Results Larger amounts of fluoride were found and recovered using diffusion than direct methods (96%–100% for diffusion vs. 67%–90% for direct). Statistically significant differences were obtained between direct and diffusion methods using different ion strength adjusters. Pretreatment methods reduced the amount of recovered fluoride. Determination of fluoride content was influenced both by the presence of NaCl and other ions in the salt. Conclusion Direct and diffusion techniques for analysis of fluoridated salt are suitable methods for fluoride analysis. The choice of method should depend on the purpose of the analysis. PMID:20088217
Method of making an integral window hermetic fiber optic component
Dalton, R.D.; Kramer, D.P.; Massey, R.T.; Waker, D.A.
1996-11-12
In the fabrication of igniters, actuators, detonators, and other pyrotechnic devices to be activated by a laser beam, an integral optical glass window is formed by placing a preform in the structural member of the device and then melting the glass and sealing it in place by heating at a temperature between the ceramming temperature of the glass and the melting point of the metal, followed by rapid furnace cooling to avoid devitrification. No other sealing material is needed to achieve hermeticity. A preferred embodiment of this type of device is fabricated by allowing the molten glass to flow further and form a plano-convex lens integral with and at the bottom of the window. The lens functions to decrease the beam divergence caused by refraction of the laser light passing through the window when the device is fired by means of a laser beam. 9 figs.
Method of making an integral window hermetic fiber optic component
Dalton, Rick D.; Kramer, Daniel P.; Massey, Richard T.; Waker, Damon A.
1996-11-12
In the fabrication of igniters, actuators, detonators, and other pyrotechnic devices to be activated by a laser beam, an integral optical glass window is formed by placing a preform in the structural member of the device and then melting the glass and sealing it in place by heating at a temperature between the ceramming temperature of the glass and the melting point of the metal, followed by rapid furnace cooling to avoid devitrification. No other sealing material is needed to achieve hermeticity. A preferred embodiment of this type of device is fabricated by allowing the molten glass to flow further and form a plano-convex lens integral with and at the bottom of the window. The lens functions to decrease the beam divergence caused by refraction of the laser light passing through the window when the device is fired by means of a laser beam.
Nuclear structure from direct reactions with rare isotopes: observables, methods and highlights
NASA Astrophysics Data System (ADS)
Obertelli, Alexandre
2016-09-01
An overview of direct reactions employed for nuclear structure studies is presented. The basic and most used analysis methods of elastic and inelastic scattering, transfer reactions and intermediate-energy removal reactions are reviewed. The most relevant observables from direct reactions regarding the nuclear many-body problem, as well as related experimental techniques, are illustrated through recent achievements with unstable nuclei.
A direct push resistivity method was evaluated as a complementary screening tool to provide rapid in-situ contaminant detection to aid in better defining locations for drilling, sampling, and monitoring well installation at hazardous waste sites. Nine continuous direct push resi...
Pesticides and public health: integrated methods of mosquito management.
Rose, R. I.
2001-01-01
Pesticides have a role in public health as part of sustainable integrated mosquito management. Other components of such management include surveillance, source reduction or prevention, biological control, repellents, traps, and pesticide-resistance management. We assess the future use of mosquito control pesticides in view of niche markets, incentives for new product development, Environmental Protection Agency registration, the Food Quality Protection Act, and improved pest management strategies for mosquito control. PMID:11266290
Methods for integrating a functional component into a microfluidic device
Simmons, Blake; Domeier, Linda; Woo, Noble; Shepodd, Timothy; Renzi, Ronald F.
2014-08-19
Injection molding is used to form microfluidic devices with integrated functional components. One or more functional components are placed in a mold cavity, which is then closed. Molten thermoplastic resin is injected into the mold and then cooled, thereby forming a solid substrate including the functional component(s). The solid substrate including the functional component(s) is then bonded to a second substrate, which may include microchannels or other features.
NASA Astrophysics Data System (ADS)
Arbatani, Siamak; Callejo, Alfonso; Kövecses, József; Kalantari, Masoud; Marchand, Nick R.; Dargahi, Javad
2016-06-01
Directional drilling is a popular technique for oil well drilling. Accurate prediction of the directional performance is critical in order to achieve the desired well profile. Simplified geometry methods are, to date, the industry standard for predicting directional performance. A comprehensive, high-fidelity method for the simulation of directional drilling is presented here. It consists of a detailed discretization of the actual geometry and a rigorous application of two modeling techniques: the finite element and the finite segment methods. By doing so, the dynamic problem is addressed from two different yet complementary perspectives: structural mechanics and rigid-body motion. Collision detection and contact dynamics algorithms are also presented. Results show that both methods agree in terms of the dynamic response, and that the build rate estimations are consistent with available experimental data. Owing to the framework efficiency and physics-based nature, the presented tools are very well-suited for design engineering and real-time simulation.
Technology Transfer Automated Retrieval System (TEKTRAN)
To determine if Campylobacter isolation method influenced antimicrobial susceptibility results, the minimum inhibitory concentrations (MIC) of nine antimicrobials were compared for 291 pairs of Campylobacter isolates recovered from chicken carcass rinse samples using direct plating and an enrichment...
Path-integral Monte Carlo method for Rényi entanglement entropies.
Herdman, C M; Inglis, Stephen; Roy, P-N; Melko, R G; Del Maestro, A
2014-07-01
We introduce a quantum Monte Carlo algorithm to measure the Rényi entanglement entropies in systems of interacting bosons in the continuum. This approach is based on a path-integral ground state method that can be applied to interacting itinerant bosons in any spatial dimension with direct relevance to experimental systems of quantum fluids. We demonstrate how it may be used to compute spatial mode entanglement, particle partitioned entanglement, and the entanglement of particles, providing insights into quantum correlations generated by fluctuations, indistinguishability, and interactions. We present proof-of-principle calculations and benchmark against an exactly soluble model of interacting bosons in one spatial dimension. As this algorithm retains the fundamental polynomial scaling of quantum Monte Carlo when applied to sign-problem-free models, future applications should allow for the study of entanglement entropy in large-scale many-body systems of interacting bosons.
NASA Technical Reports Server (NTRS)
Gottlieb, D.; Turkel, E.
1980-01-01
New methods are introduced for the time integration of the Fourier and Chebyshev methods of solution for dynamic differential equations. These methods are unconditionally stable, even though no matrix inversions are required. Time steps are chosen by accuracy requirements alone. For the Fourier method both leapfrog and Runge-Kutta methods are considered. For the Chebyshev method only Runge-Kutta schemes are tested. Numerical calculations are presented to verify the analytic results. Applications to the shallow water equations are presented.
Improving the accuracy of multiple integral evaluation by applying Romberg's method
NASA Astrophysics Data System (ADS)
Zhidkov, E. P.; Lobanov, Yu. Yu.; Rushai, V. D.
2009-02-01
Romberg’s method, which is used to improve the accuracy of one-dimensional integral evaluation, is extended to multiple integrals if they are evaluated using the product of composite quadrature formulas. Under certain conditions, the coefficients of the Romberg formula are independent of the integral’s multiplicity, which makes it possible to use a simple evaluation algorithm developed for one-dimensional integrals. As examples, integrals of multiplicity two to six are evaluated by Romberg’s method and the results are compared with other methods.
Where is the forgetting with list-method directed forgetting in recognition?
Sahakyan, Lili; Waldum, Emily R.; Benjamin, Aaron S.; Bickett, Samuel P.
2010-01-01
Despite the fact that list-method directed forgetting instruction leads to decreases in memory performance on tests of free recall, there are to date no published reports of comparable effects in recognition testing. This paper evaluates whether conditions that promote the importance of context in recognition, either via stimulus selection (Experiments 1 and 2) or by test choice (Experiment 3), elicit directed forgetting impairment. In all three experiments, we obtained reliable recognition deficits, suggesting that the typical conditions of recognition, rather than recognition itself, underlie the discrepancy between the tests of recognition and free recall in list-method directed forgetting. PMID:19460953
A novel method of fabricating integrated FETs for MEMS applications.
Okandan, Murat; Bennett, Reid Stuart; Draper, Bruce Leroy; Mani, Seethambal S.
2003-07-01
This paper demonstrates a simple technique for building n-channel MOSFETs and complex micromechanical systems simultaneously instead of serially, allowing a more straightforward integration of complete systems. The fabrication sequence uses few additional process steps and only one additional masking layer compared to a MEMS-only technology. The process flow forms the MOSFET gate electrode using the first level of mechanical polycrystalline silicon, while the MOSFET source and drain regions are formed by dopant diffusions into the substrate from subsequent levels of heavily doped poly that is used for mechanical elements. The process yields devices with good, repeatable electrical characteristics suitable for a wide range of digital and analog applications.
Assembly and method for testing the integrity of stuffing tubes
Morrison, E.F.
1997-08-26
A stuffing tube integrity checking assembly includes first and second annular seals, with each seal adapted to be positioned about a stuffing tube penetration component. An annular inflation bladder is provided, the bladder having a slot extending longitudinally there along and including a separator for sealing the slot. A first valve is in fluid communication with the bladder for introducing pressurized fluid to the space defined by the bladder when mounted about the tube. First and second releasible clamps are provided. Each clamp assembly is positioned about the bladder for securing the bladder to one of the seals for thereby establishing a fluid-tight chamber about the tube. 5 figs.
Assembly and method for testing the integrity of stuffing tubes
Morrison, Edward Francis
1997-01-01
A stuffing tube integrity checking assembly includes first and second annular seals, with each seal adapted to be positioned about a stuffing tube penetration component. An annular inflation bladder is provided, the bladder having a slot extending longitudinally therealong and including a separator for sealing the slot. A first valve is in fluid communication with the bladder for introducing pressurized fluid to the space defined by the bladder when mounted about the tube. First and second releasible clamps are provided. Each clamp assembly is positioned about the bladder for securing the bladder to one of the seals for thereby establishing a fluid-tight chamber about the tube.
Phase-integral method for the radial Dirac equation
Linnæus, Staffan
2014-09-15
A phase-integral (WKB) solution of the radial Dirac equation is calculated up to the third order of approximation, retaining perfect symmetry between the two components of the wave function and introducing no singularities except at the zeroth-order transition points. The potential is allowed to be of scalar, vector, or tensor type, or any combination of these. The connection problem is investigated in detail. Explicit formulas are given for single-turning-point phase shifts and single-well energy levels.
A new method for taming tensor sum-integrals
NASA Astrophysics Data System (ADS)
Ghisoiu, Ioan; Schröder, York
2012-11-01
We report on the computation of a class of massless bosonic three-loop vacuum sum-integrals which are key building blocks for an evaluation of the Debye screening mass in hot QCD. Generalizing known techniques and introducing the concept of tensor reduction by dimensionality shifts (known to the zero-temperature community since the work of Tarasov in 1996) to finite temperature, we are able to treat hitherto unaccessible cases, which will allow us to finalize the long-term project of NNLO Debye mass evaluation.
Method research and developing a method to control directed semiconductor crystallization in space
NASA Astrophysics Data System (ADS)
Ginkin, V. P.; Folomeev, V. I.; Lukhanova, T. M.; Rakov, V. V.; Maronchuk, I. I.; Kartavykh, A. V.; Egorov, A. V.
2002-03-01
A system and procedure for simultaneously monitoring temperatures along the melt and crystal axis, those on the external surface of the quartz ampoule and in various elements of the "Polyzone" facility's thermal unit have been developed. A detailed 2D-picture has been obtained of spatial-time temperature fields evolutions in the ampoule and in the thermal unit during the crystal growth process using directed crystallization. A mathematical model has been created and parametrical calculations of the growth process have been carried out.
Stone, Adam; Jain, Himanshu; Dierolf, Volkmar; Sakakura, Masaaki; Shimotsuma, Yasuhiko; Miura, Kiyotaka; Hirao, Kazuyuki; Lapointe, Jerome; Kashyap, Raman
2015-01-01
Direct three-dimensional laser writing of amorphous waveguides inside glass has been studied intensely as an attractive route for fabricating photonic integrated circuits. However, achieving essential nonlinear-optic functionality in such devices will also require the ability to create high-quality single-crystal waveguides. Femtosecond laser irradiation is capable of crystallizing glass in 3D, but producing optical-quality single-crystal structures suitable for waveguiding poses unique challenges that are unprecedented in the field of crystal growth. In this work, we use a high angular-resolution electron diffraction method to obtain the first conclusive confirmation that uniform single crystals can be grown inside glass by femtosecond laser writing under optimized conditions. We confirm waveguiding capability and present the first quantitative measurement of power transmission through a laser-written crystal-in-glass waveguide, yielding loss of 2.64 dB/cm at 1530 nm. We demonstrate uniformity of the crystal cross-section down the length of the waveguide and quantify its birefringence. Finally, as a proof-of-concept for patterning more complex device geometries, we demonstrate the use of dynamic phase modulation to grow symmetric crystal junctions with single-pass writing. PMID:25988599
Stone, Adam; Jain, Himanshu; Dierolf, Volkmar; Sakakura, Masaaki; Shimotsuma, Yasuhiko; Miura, Kiyotaka; Hirao, Kazuyuki; Lapointe, Jerome; Kashyap, Raman
2015-01-01
Direct three-dimensional laser writing of amorphous waveguides inside glass has been studied intensely as an attractive route for fabricating photonic integrated circuits. However, achieving essential nonlinear-optic functionality in such devices will also require the ability to create high-quality single-crystal waveguides. Femtosecond laser irradiation is capable of crystallizing glass in 3D, but producing optical-quality single-crystal structures suitable for waveguiding poses unique challenges that are unprecedented in the field of crystal growth. In this work, we use a high angular-resolution electron diffraction method to obtain the first conclusive confirmation that uniform single crystals can be grown inside glass by femtosecond laser writing under optimized conditions. We confirm waveguiding capability and present the first quantitative measurement of power transmission through a laser-written crystal-in-glass waveguide, yielding loss of 2.64 dB/cm at 1530 nm. We demonstrate uniformity of the crystal cross-section down the length of the waveguide and quantify its birefringence. Finally, as a proof-of-concept for patterning more complex device geometries, we demonstrate the use of dynamic phase modulation to grow symmetric crystal junctions with single-pass writing. PMID:25988599
Direct method for second-order sensitivity analysis of modal assurance criterion
NASA Astrophysics Data System (ADS)
Lei, Sheng; Mao, Kuanmin; Li, Li; Xiao, Weiwei; Li, Bin
2016-08-01
A Lagrange direct method is proposed to calculate the second-order sensitivity of modal assurance criterion (MAC) values of undamped systems. The eigenvalue problem and normalizations of eigenvectors, which augmented by using some Lagrange multipliers, are used as the constraints of the Lagrange functional. Once the Lagrange multipliers are determined, the sensitivities of MAC values can be evaluated directly. The Lagrange direct method is accurate, efficient and easy to implement. A simply supported beam is utilized to check the accuracy of the proposed method. A frame is adopted to validate the predicting capacity of the first- and second-order sensitivities of MAC values. It is shown that the computational costs of the proposed method can be remarkably reduced in comparison with those of the indirect method without loss of accuracy.
NASA Astrophysics Data System (ADS)
Pandey, Siddharth; Borders, Tammie L.; Hernández, Carmen E.; Roy, Lindsay E.; Reddy, Gaddum D.; Martinez, Geo L.; Jackson, Autumn; Brown, Guenevere; Acree, William E., Jr.
1999-01-01
An undergraduate laboratory experiment is designed for the quantitative determination of quinine in tonic water samples. It is based upon direct fluorescence emission and first-derivative spectroscopic methods. Unlike other published laboratory experiments, our method exposes students to the general method of derivative spectroscopy, an important, often-used analytical technique for eliminating sample matrix and background absorbance effects and for treating overlapped spectral bands. The statistical treatment allows students to compare concentrations directly calculated from the measured fluorescence emission intensity with values obtained from the first-derivative emission spectra, to ascertain whether there is a difference between the two analytical methods. Method selection and validation are important items routinely encountered by practicing analytical chemists.
NASA Astrophysics Data System (ADS)
Plakhov, Iu. V.; Mytsenko, A. V.; Shel'Pov, V. A.
A numerical integration method is developed that is more accurate than Everhart's (1974) implicit single-sequence approach for integrating orbits. This method can be used to solve problems of space geodesy based on the use of highly precise laser observations.
Altamirano Bentolila, Patricia; Clark, Carmen; Stabile, Carmen
2014-01-01
Starting from historical records attempts to identify the events which made possible the creation and regulation of Welfare Student Department. A Decade of 60 and 70 was fruitful for starting and development of first institutional politics designed to attend the health and welfare of students. In that way, the actions of Welfare Student Direction and Vocational Guidance focus their objective to bring on welfare, permanence, development of university student. It stand out the accent put it on the integral health exam of students, the concern about the empty in his cultural training, the possibility of make it easier vocational support and the execution of health insurance.
NASA Astrophysics Data System (ADS)
Vanavil, B.; Krishna Chaitanya, K.; Seshagiri Rao, A.
2015-06-01
In this paper, a proportional-integral-derivative controller in series with a lead-lag filter is designed for control of the open-loop unstable processes with time delay based on direct synthesis method. Study of the performance of the designed controllers has been carried out on various unstable processes. Set-point weighting is considered to reduce the undesirable overshoot. The proposed scheme consists of only one tuning parameter, and systematic guidelines are provided for selection of the tuning parameter based on the peak value of the sensitivity function (Ms). Robustness analysis has been carried out based on sensitivity and complementary sensitivity functions. Nominal and robust control performances are achieved with the proposed method and improved closed-loop performances are obtained when compared to the recently reported methods in the literature.
Direct SQP-methods for solving optimal control problems with delays
Goellmann, L.; Bueskens, C.; Maurer, H.
1994-12-31
The maximum principle for optimal control problems with delays leads to a boundary value problem (BVP) which is retarded in the state and advanced in the costate function. Based on shooting techniques, solution methods for this type of BVP have been proposed. In recent years, direct optimization methods have been favored for solving control problems without delays. Direct methods approximate the control and the state over a fixed mesh and solve the resulting NLP-problem with SQP-methods. These methods dispense with the costate function and have shown to be robust and efficient. In this paper, we propose a direct SQP-method for retarded control problems. In contrast to conventional direct methods, only the control variable is approximated by e.g. spline-functions. The state is computed via a high order Runge-Kutta type algorithm and does not enter explicitly the NLP-problem through an equation. This approach reduces the number of optimization variables considerably and is implementable even on a PC. Our method is illustrated by the numerical solution of retarded control problems with constraints. In particular, we consider the control of a continuous stirred tank reactor which has been solved by dynamic programming. This example illustrates the robustness and efficiency of the proposed method. Open questions concerning sufficient conditions and convergence of discretized NLP-problems are discussed.
The general 2-D moments via integral transform method for acoustic radiation and scattering
NASA Astrophysics Data System (ADS)
Smith, Jerry R.; Mirotznik, Mark S.
2001-05-01
The moments via integral transform method (MITM) is a technique to analytically reduce the 2-D method of moments (MoM) impedance double integrals into single integrals. By using a special integral representation of the Green's function, the impedance integral can be analytically simplified to a single integral in terms of transformed shape and weight functions. The reduced expression requires fewer computations and reduces the fill times of the MoM impedance matrix. Furthermore, the resulting integral is analytic for nearly arbitrary shape and weight function sets. The MITM technique is developed for mixed boundary conditions and predictions with basic shape and weight function sets are presented. Comparisons of accuracy and speed between MITM and brute force are presented. [Work sponsored by ONR and NSWCCD ILIR Board.
Yang, XiaoMin; Xiao, Shuaigang; Hu, Wei; Hwu, Justin; van de Veerdonk, René; Wago, Koichi; Lee, Kim; Kuo, David
2014-10-01
We propose a novel strategy to integrate the nanoimprint lithography (NIL) technique with directed self-assembly (DSA) of block copolymer (BCP) for providing a robust, high-yield, and low-defect-density path to sub-20 nm dense patterning. Through this new NIL-DSA method, UV nanoimprint resist is used as the DSA copolymer pre-pattern to expedite the DSA process. This method was successfully used to fabricate a 1.0 Td in(-2) servo-integrated nanoimprint template for bit-patterned media (BPM) application. The fabricated template was used for UV-cure NIL on a 2.5-inch disk. The imprint resist patterns were further transferred into the underlying CoCrPt magnetic layer through a carbon hard mask using ion beam etching. The successful integration of the NIL technique with the DSA process provides us with a new route to BPM nanofabrication, which includes the following three major advantages: (1) a simpler and faster way to implement DSA for high-density BPM patterning; (2) a novel method for fabricating a high-quality dot pattern template through an iterative imprint-DSA-template procedure; and (3) an uncomplicated integration scheme for implementing non-periodic servo features with BCP patterns, thus accelerating the transition of moving the DSA technique from laboratory research to the BPM manufacturing environment.
Yang, XiaoMin; Xiao, Shuaigang; Hu, Wei; Hwu, Justin; van de Veerdonk, René; Wago, Koichi; Lee, Kim; Kuo, David
2014-10-01
We propose a novel strategy to integrate the nanoimprint lithography (NIL) technique with directed self-assembly (DSA) of block copolymer (BCP) for providing a robust, high-yield, and low-defect-density path to sub-20 nm dense patterning. Through this new NIL-DSA method, UV nanoimprint resist is used as the DSA copolymer pre-pattern to expedite the DSA process. This method was successfully used to fabricate a 1.0 Td in(-2) servo-integrated nanoimprint template for bit-patterned media (BPM) application. The fabricated template was used for UV-cure NIL on a 2.5-inch disk. The imprint resist patterns were further transferred into the underlying CoCrPt magnetic layer through a carbon hard mask using ion beam etching. The successful integration of the NIL technique with the DSA process provides us with a new route to BPM nanofabrication, which includes the following three major advantages: (1) a simpler and faster way to implement DSA for high-density BPM patterning; (2) a novel method for fabricating a high-quality dot pattern template through an iterative imprint-DSA-template procedure; and (3) an uncomplicated integration scheme for implementing non-periodic servo features with BCP patterns, thus accelerating the transition of moving the DSA technique from laboratory research to the BPM manufacturing environment. PMID:25189432
NASA Technical Reports Server (NTRS)
1971-01-01
Individualized program direct costs for each satellite program are presented. This breakdown provides the activity level dependent costs for each satellite program. The activity level dependent costs, or, more simply, program direct costs, are comprised of the total payload costs (as these costs are strictly program dependent) and the direct launch vehicle costs. Only those incremental launch vehicle costs associated directly with the satellite program are considered. For expendable launch vehicles the direct costs include the vehicle investment hardware costs and the launch operations costs. For the reusable STS vehicles the direct costs include only the launch operations, recovery operations, command and control, vehicle maintenance, and propellant support. The costs associated with amortization of reusable vehicle investment, RDT&E range support, etc., are not included.
Evaluation of direct saponification method for determination of cholesterol in meats.
Adams, M L; Sullivan, D M; Smith, R L; Richter, E F
1986-01-01
A gas chromatographic (GC) method has been developed for determination of cholesterol in meats. The method involves ethanolic KOH saponification of the sample material, homogeneous-phase toluene extraction of the unsaponifiables, derivatization of cholesterol to its trimethylsilylether, and quantitation by GC-flame ionization detection using 5-alpha-cholestane as internal standard. This direct saponification method is compared with the current AOAC official method for determination of cholesterol in 20 different meat products. The direct saponification method eliminates the need for initial lipid extraction, thus offering a 30% savings in labor, and requires fewer solvents than the AOAC method. It produced comparable or slightly higher cholesterol results than the AOAC method in all meat samples examined. Precision, determined by assaying a turkey meat sample 16 times over 4 days, was excellent (CV = 1.74%). Average recovery of cholesterol added to meat samples was 99.8%.
NASA Astrophysics Data System (ADS)
Gutsch, Manuela; Choi, Kang-Hoon; Hanisch, Norbert; Hohle, Christoph; Seidel, Robert; Steidel, Katja; Thrun, Xaver; Werner, Thomas
2014-10-01
Many efforts were spent in the development of EUV technologies, but from a customer point of view EUV is still behind expectations. In parallel since years maskless lithography is included in the ITRS roadmap wherein multi electron beam direct patterning is considered as an alternative or complementary approach for patterning of advanced technology nodes. The process of multi beam exposures can be emulated by single beam technologies available in the field. While variable shape-beam direct writers are already used for niche applications, the integration capability of e-beam direct write at advanced nodes has not been proven, yet. In this study the e-beam lithography was implemented in the BEoL processes of the 28nm SRAM technology. Integrated 300mm wafers with a 28nm back-end of line (BEoL) stack from GLOBALFOUNDRIES, Dresden, were used for the experiments. For the patterning of the Metal layer a Mix and Match concept based on the sequence litho - etch - litho - etch (LELE) was developed and evaluated wherein several exposure fields were blanked out during the optical exposure. E-beam patterning results of BEoL Metal and Via layers are presented using a 50kV VISTEC SB3050DW variable shaped electron beam direct writer at Fraunhofer IPMS-CNT. Etch results are shown and compared to the POR. In summary we demonstrate the integration capability of EBDW into a productive CMOS process flow at the example of the 28nm SRAM technology node.