Optimization of Selective Laser Melting by Evaluation Method of Multiple Quality Characteristics

NASA Astrophysics Data System (ADS)

Khaimovich, A. I.; Stepanenko, I. S.; Smelov, V. G.

2018-01-01

Article describes the adoption of the Taguchi method in selective laser melting process of sector of combustion chamber by numerical and natural experiments for achieving minimum temperature deformation. The aim was to produce a quality part with minimum amount of numeric experiments. For the study, the following optimization parameters (independent factors) were chosen: the laser beam power and velocity; two factors for compensating the effect of the residual thermal stresses: the scale factor of the preliminary correction of the part geometry and the number of additional reinforcing elements. We used an orthogonal plan of 9 experiments with a factor variation at three levels (L9). As quality criterias, the values of distortions for 9 zones of the combustion chamber and the maximum strength of the material of the chamber were chosen. Since the quality parameters are multidirectional, a grey relational analysis was used to solve the optimization problem for multiple quality parameters. As a result, according to the parameters obtained, the combustion chamber segments of the gas turbine engine were manufactured.

Extension of the firefly algorithm and preference rules for solving MINLP problems

NASA Astrophysics Data System (ADS)

Costa, M. Fernanda P.; Francisco, Rogério B.; Rocha, Ana Maria A. C.; Fernandes, Edite M. G. P.

2017-07-01

An extension of the firefly algorithm (FA) for solving mixed-integer nonlinear programming (MINLP) problems is presented. Although penalty functions are nowadays frequently used to handle integrality conditions and inequality and equality constraints, this paper proposes the implementation within the FA of a simple rounded-based heuristic and four preference rules to find and converge to MINLP feasible solutions. Preliminary numerical experiments are carried out to validate the proposed methodology.

Hydrostatic calculations of axisymmetric flow and its stability for the AGCE model

NASA Technical Reports Server (NTRS)

Miller, T. L.; Gall, R. L.

1981-01-01

Baroclinic waves in the atmospherics general circulation experiment (AGCE) apparatus by the use of numerical hydrostatic primitive equation models were determined. The calculation is accomplished by using an axisymmetric primitive equation model to compute, for a given set of experimental parameters, a steady state axisymmetric flow and then testing this axisymmetric flow for stability using a linear primitive equation model. Some axisymmetric flows are presented together with preliminary stability calculations.

A survey of hard X-ray imaging concepts currently proposed for viewing solar flares

NASA Technical Reports Server (NTRS)

Campbell, Jonathan W.; Davis, John M.; Emslie, A. G.

1991-01-01

Several approaches to imaging hard X-rays emitted from solar flares have been proposed. These include the fixed modulation collimator, the rotating modulation collimator, the spiral fresnel zone pattern, and the redundantly coded aperture. These techniques are under consideration for use in the Solar Maximum '91 balloon program, the Japanese Solar-A satellite, the Controls, Astrophysics, and Structures Experiment in Space, and the Pinhole/Occulter Facility and are outlined and discussed in the context of preliminary results from numerical modeling and the requirements derived from current ideas as to the expected hard X-ray structures in the impulsive phase of solar flares. Preliminary indications are that all of the approaches are promising, but each has its own unique set of limitations.

Numerical bias in bounded and unbounded number line tasks.

PubMed

Cohen, Dale J; Blanc-Goldhammer, Daryn

2011-04-01

The number line task is often used to assess children's and adults' underlying representations of integers. Traditional bounded number line tasks, however, have limitations that can lead to misinterpretation. Here we present a new task, an unbounded number line task, that overcomes these limitations. In Experiment 1, we show that adults use a biased proportion estimation strategy to complete the traditional bounded number line task. In Experiment 2, we show that adults use a dead-reckoning integer estimation strategy in our unbounded number line task. Participants revealed a positively accelerating numerical bias in both tasks, but showed scalar variance only in the unbounded number line task. We conclude that the unbounded number line task is a more pure measure of integer representation than the bounded number line task, and using these results, we present a preliminary description of adults' underlying representation of integers.

A general model-based design of experiments approach to achieve practical identifiability of pharmacokinetic and pharmacodynamic models.

PubMed

Galvanin, Federico; Ballan, Carlo C; Barolo, Massimiliano; Bezzo, Fabrizio

2013-08-01

The use of pharmacokinetic (PK) and pharmacodynamic (PD) models is a common and widespread practice in the preliminary stages of drug development. However, PK-PD models may be affected by structural identifiability issues intrinsically related to their mathematical formulation. A preliminary structural identifiability analysis is usually carried out to check if the set of model parameters can be uniquely determined from experimental observations under the ideal assumptions of noise-free data and no model uncertainty. However, even for structurally identifiable models, real-life experimental conditions and model uncertainty may strongly affect the practical possibility to estimate the model parameters in a statistically sound way. A systematic procedure coupling the numerical assessment of structural identifiability with advanced model-based design of experiments formulations is presented in this paper. The objective is to propose a general approach to design experiments in an optimal way, detecting a proper set of experimental settings that ensure the practical identifiability of PK-PD models. Two simulated case studies based on in vitro bacterial growth and killing models are presented to demonstrate the applicability and generality of the methodology to tackle model identifiability issues effectively, through the design of feasible and highly informative experiments.

Analysis of low gravity tolerance of model experiments for space station: Preliminary results for directional solidification

NASA Technical Reports Server (NTRS)

Alexander, J. Iwan D.; Ouazzani, Jalil

1988-01-01

It has become clear from measurements of the acceleration environment in the Spacelab that the residual gravity levels on board a spacecraft in low Earth orbit can be significant and should be of concern to experimenters who wish to take advantage of the low gravity conditions on future Spacelab missions and on board the Space Station. The basic goals are to better understand the low gravity tolerance of three classes of materials science experiments: crystal growth from a melt, a vapor, and a solution. The results of the research will provide guidance toward the determination of the sensitivity of the low gravity environment, the design of the laboratory facilites, and the timelining of materials science experiments. To data, analyses of the effects of microgravity environment were, with a few exceptions, restricted to order of magnitude estimates. Preliminary results obtained from numerical models of the effects of residual steady and time dependent acceleration are reported on: heat, mass, and momentum transport during the growth of a dilute alloy by the Bridgman-Stockbarger technique, and the response of a simple fluid physics experiment involving buoyant convection in a square cavity.

Development of a severe local storm prediction system: A 60-day test of a mesoscale primitive equation model

NASA Technical Reports Server (NTRS)

Paine, D. A.; Zack, J. W.; Kaplan, M. L.

1979-01-01

The progress and problems associated with the dynamical forecast system which was developed to predict severe storms are examined. The meteorological problem of severe convective storm forecasting is reviewed. The cascade hypothesis which forms the theoretical core of the nested grid dynamical numerical modelling system is described. The dynamical and numerical structure of the model used during the 1978 test period is presented and a preliminary description of a proposed multigrid system for future experiments and tests is provided. Six cases from the spring of 1978 are discussed to illustrate the model's performance and its problems. Potential solutions to the problems are examined.

An Overview of the International H2O Project (IHOP_2002) and Some Preliminary Highlights.

NASA Astrophysics Data System (ADS)

Weckwerth, Tammy M.; Parsons, David B.; Koch, Steven E.; Moore, James A.; Lemone, Margaret A.; Demoz, Belay B.; Flamant, Cyrille; Geerts, Bart; Wang, Junhong; Feltz, Wayne F.

2004-02-01

The International H2O Project (IHOP_2002) is one of the largest North American meteorological field experiments in history. From 13 May to 25 June 2002, over 250 researchers and technical staff from the United States, Germany, France, and Canada converged on the Southern Great Plains to measure water vapor and other atmospheric variables. The principal objective of IHOP_2002 is to obtain an improved characterization of the time-varying three-dimensional water vapor field and evaluate its utility in improving the understanding and prediction of convective processes. The motivation for this objective is the combination of extremely low forecast skill for warm-season rainfall and the relatively large loss of life and property from flash floods and other warm-season weather hazards. Many prior studies on convective storm forecasting have shown that water vapor is a key atmospheric variable that is insufficiently measured. Toward this goal, IHOP_2002 brought together many of the existing operational and new state-of-the-art research water vapor sensors and numerical models.The IHOP_2002 experiment comprised numerous unique aspects. These included several instruments fielded for the first time (e.g., reference radiosonde); numerous upgraded instruments (e.g., Wyo-ming Cloud Radar); the first ever horizontal-pointing water vapor differential absorption lidar (DIAL; i.e., Leandre II on the Naval Research Laboratory P-3), which required the first onboard aircraft avoidance radar; several unique combinations of sensors (e.g., multiple profiling instruments at one field site and the German water vapor DIAL and NOAA/Environmental Technology Laboratory Doppler lidar on board the German Falcon aircraft); and many logistical challenges. This article presents a summary of the motivation, goals, and experimental design of the project, illustrates some preliminary data collected, and includes discussion on some potential operational and research implications of the experiment.

Numerical and Experimental Investigation of the Electromechanical Behavior of REBCO Tapes

NASA Astrophysics Data System (ADS)

Allen, N. C.; Chiesa, L.; Takayasu, M.

2015-12-01

To fully characterize the electromechanical behavior of a Twisted Stacked-Tape Cable (TSTC) it is important to understand the performance of the individual REBCO tapes under various loading conditions. Numerical modeling and experimentation have been used to investigate the electromechanical characteristics of two commercially available REBCO tapes (SuperPower and SuNAM). Tension and combined tension-torsion experiments on single tapes have been continued, from prior preliminary studies, to characterize their critical current behavior and mechanical strength. Additionally, structural finite element analysis was performed on single tapes under tension and combined tension-torsion to investigate the strain dependence of the critical current. The numerical results were compared to the experimental findings for validation. The SuNAM experimental data matched the numerical model very well while the SuperPower tape experienced degradation at lower stress and strain than predicted in the model. The Superpower tape also displayed greater variability in critical current between different samples as compared with the SuNAM tape.

Cone-beam reconstruction for the two-circles-plus-one-line trajectory

NASA Astrophysics Data System (ADS)

Lu, Yanbin; Yang, Jiansheng; Emerson, John W.; Mao, Heng; Zhou, Tie; Si, Yuanzheng; Jiang, Ming

2012-05-01

The Kodak Image Station In-Vivo FX has an x-ray module with cone-beam configuration for radiographic imaging but lacks the functionality of tomography. To introduce x-ray tomography into the system, we choose the two-circles-plus-one-line trajectory by mounting one translation motor and one rotation motor. We establish a reconstruction algorithm by applying the M-line reconstruction method. Numerical studies and preliminary physical phantom experiment demonstrate the feasibility of the proposed design and reconstruction algorithm.

Modeling of Convective-Stratiform Precipitation Processes: Sensitivity to Partitioning Methods and Numerical Advection Schemes

NASA Technical Reports Server (NTRS)

Lang, Steve; Tao, W.-K.; Simpson, J.; Ferrier, B.; Einaudi, Franco (Technical Monitor)

2001-01-01

Six different convective-stratiform separation techniques, including a new technique that utilizes the ratio of vertical and terminal velocities, are compared and evaluated using two-dimensional numerical simulations of a tropical [Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE)] and midlatitude continental [Preliminary Regional Experiment for STORM-Central (PRESTORM)] squall line. The simulations are made using two different numerical advection schemes: 4th order and positive definite advection. Comparisons are made in terms of rainfall, cloud coverage, mass fluxes, apparent heating and moistening, mean hydrometeor profiles, CFADs (Contoured Frequency with Altitude Diagrams), microphysics, and latent heating retrieval. Overall, it was found that the different separation techniques produced results that qualitatively agreed. However, the quantitative differences were significant. Observational comparisons were unable to conclusively evaluate the performance of the techniques. Latent heating retrieval was shown to be sensitive to the use of separation technique mainly due to the stratiform region for methods that found very little stratiform rain. The midlatitude PRESTORM simulation was found to be nearly invariant with respect to advection type for most quantities while for TOGA COARE fourth order advection produced numerous shallow convective cores and positive definite advection fewer cells that were both broader and deeper penetrating above the freezing level.

Shock Melting of Permafrost on Mars: Water Ice Multiphase Equation of State for Numerical Modeling and Its Testing

NASA Technical Reports Server (NTRS)

Ivanov, B. A.

2005-01-01

The presence of water/ice/brine in upper layers of Martian crust affects many processes of impact cratering. Modeling of these effects promises better understanding of Martian cratering records. We present here the new ANEOS-based multiphase equation of state for water/ice constructed for usage in hydrocodes and first numerical experiments on permafrost shock melting. Preliminary results show that due to multiple shock compression of ice inclusions in rocks the entropy jump in shocked ice is smaller than in pure ice for the same shock pressure. Hence previous estimates of ice melting during impact cratering on Mars should be re-evaluated. Additional information is included in the original extended abstract.

Simulation of Plasma Jet Merger and Liner Formation within the PLX- α Project

NASA Astrophysics Data System (ADS)

Samulyak, Roman; Chen, Hsin-Chiang; Shih, Wen; Hsu, Scott

2015-11-01

Detailed numerical studies of the propagation and merger of high Mach number argon plasma jets and the formation of plasma liners have been performed using the newly developed method of Lagrangian particles (LP). The LP method significantly improves accuracy and mathematical rigor of common particle-based numerical methods such as smooth particle hydrodynamics while preserving their main advantages compared to grid-based methods. A brief overview of the LP method will be presented. The Lagrangian particle code implements main relevant physics models such as an equation of state for argon undergoing atomic physics transformation, radiation losses in thin optical limit, and heat conduction. Simulations of the merger of two plasma jets are compared with experimental data from past PLX experiments. Simulations quantify the effect of oblique shock waves, ionization, and radiation processes on the jet merger process. Results of preliminary simulations of future PLX- alpha experiments involving the ~ π / 2 -solid-angle plasma-liner configuration with 9 guns will also be presented. Partially supported by ARPA-E's ALPHA program.

Overview of the Lockheed Martin Compact Fusion Reactor (CFR) Project

NASA Astrophysics Data System (ADS)

McGuire, Thomas

2017-10-01

The Lockheed Martin Compact Fusion Reactor (CFR) Program endeavors to quickly develop a compact fusion power plant with favorable commercial economics and military utility. The CFR uses a diamagnetic, high beta, magnetically encapsulated, linear ring cusp plasma confinement scheme. Major project activities will be reviewed, including the T4B and T5 plasma heating experiments. The goal of the experiments is to demonstrate a suitable plasma target for heating experiments, to characterize the behavior of plasma sources in the CFR configuration and to then heat the plasma with neutral beams, with the plasma transitioning into the high Beta confinement regime. The design and preliminary results of the experiments will be presented, including discussion of predicted behavior, plasma sources, heating mechanisms, diagnostics suite and relevant numerical modeling. ©2017 Lockheed Martin Corporation. All Rights Reserved.

Cold plasma processing of local planetary ores for oxygen and metallurgically important metals

NASA Technical Reports Server (NTRS)

Lynch, D. C.; Bullard, D.; Ortega, R.

1990-01-01

The utilization of a cold plasma in chlorination processing is described. Essential equipment and instruments were received, the experimental apparatus assembled and tested, and preliminary experiments conducted. The results of the latter lend support to the original hypothesis: a cold plasma can both significantly enhance and bias chemical reactions. In two separate experiments, a cold plasma was used to reduce TiCl4 vapor and chlorinate ilmenite. The latter, reacted in an argon-chlorine plasma, yielded oxygen. The former experiment reveals that chlorine can be recovered as HCl vapor from metal chlorides in a hydrogen plasma. Furthermore, the success of the hydrogen experiments has lead to an analysis of the feasibility of direct hydrogen reduction of metal oxides in a cold plasma. That process would produce water vapor and numerous metal by-products.

Computational investigations of low-emission burner facilities for char gas burning in a power boiler

NASA Astrophysics Data System (ADS)

Roslyakov, P. V.; Morozov, I. V.; Zaychenko, M. N.; Sidorkin, V. T.

2016-04-01

Various variants for the structure of low-emission burner facilities, which are meant for char gas burning in an operating TP-101 boiler of the Estonia power plant, are considered. The planned increase in volumes of shale reprocessing and, correspondingly, a rise in char gas volumes cause the necessity in their cocombustion. In this connection, there was a need to develop a burner facility with a given capacity, which yields effective char gas burning with the fulfillment of reliability and environmental requirements. For this purpose, the burner structure base was based on the staging burning of fuel with the gas recirculation. As a result of the preliminary analysis of possible structure variants, three types of early well-operated burner facilities were chosen: vortex burner with the supply of recirculation gases into the secondary air, vortex burner with the baffle supply of recirculation gases between flows of the primary and secondary air, and burner facility with the vortex pilot burner. Optimum structural characteristics and operation parameters were determined using numerical experiments. These experiments using ANSYS CFX bundled software of computational hydrodynamics were carried out with simulation of mixing, ignition, and burning of char gas. Numerical experiments determined the structural and operation parameters, which gave effective char gas burning and corresponded to required environmental standard on nitrogen oxide emission, for every type of the burner facility. The burner facility for char gas burning with the pilot diffusion burner in the central part was developed and made subject to computation results. Preliminary verification nature tests on the TP-101 boiler showed that the actual content of nitrogen oxides in burner flames of char gas did not exceed a claimed concentration of 150 ppm (200 mg/m3).

A nearshore processes field experiment at Cape Hatteras, North Carolina, U.S.A.

USGS Publications Warehouse

List, Jeffrey H.; Warner, John C.; Thieler, E. Robert; Haas, Kevin; Voulgaris, George; McNinch, Jesse E.; Brodie, Katherine L.; Rosati, Julie D.; Wang, Ping; Roberts, Tiffany M.

2011-01-01

A month-long field experiment focused on the nearshore hydrodynamics of Diamond Shoals adjacent to Cape Hatteras Point, North Carolina, was conducted in February 2010. The objectives of this multi-institutional experiment were to test hypotheses related to Diamond Shoals as a sink in the regional sediment budget and to provide data for evaluating numerical models. The experiment included in-situ instrumentation for measuring waves and currents; a video camera system for measuring surface currents at a nearshore transect; a radar system for measuring regional surface currents over Diamond Shoals and the adjacent coast; a vehicle-based scanning lidar and radar system for mapping beach topography, nearshore wave breaking intensity, bathymetry (through wave celerity inversion), and wave direction; and an amphibious vehicle system for surveying single-beam bathymetry. Preliminary results from wave and current measurements suggest that shoal-building processes were active during the experiment.

The route to chaos for the Kuramoto-Sivashinsky equation

NASA Technical Reports Server (NTRS)

Papageorgiou, Demetrios T.; Smyrlis, Yiorgos

1990-01-01

The results of extensive numerical experiments of the spatially periodic initial value problem for the Kuramoto-Sivashinsky equation. This paper is concerned with the asymptotic nonlinear dynamics at the dissipation parameter decreases and spatio-temporal chaos sets in. To this end the initial condition is taken to be the same for all numerical experiments (a single sine wave is used) and the large time evolution of the system is followed numerically. Numerous computations were performed to establish the existence of windows, in parameter space, in which the solution has the following characteristics as the viscosity is decreased: a steady fully modal attractor to a steady bimodal attractor to another steady fully modal attractor to a steady trimodal attractor to a periodic attractor, to another steady fully modal attractor, to another periodic attractor, to a steady tetramodal attractor, to another periodic attractor having a full sequence of period-doublings (in parameter space) to chaos. Numerous solutions are presented which provide conclusive evidence of the period-doubling cascades which precede chaos for this infinite-dimensional dynamical system. These results permit a computation of the length of subwindows which in turn provide an estimate for their successive ratios as the cascade develops. A calculation based on the numerical results is also presented to show that the period doubling sequences found here for the Kuramoto-Sivashinsky equation, are in complete agreement with Feigenbaum's universal constant of 4,669201609... . Some preliminary work shows several other windows following the first chaotic one including periodic, chaotic, and a steady octamodal window; however, the windows shrink significantly in size to enable concrete quantitative conclusions to be made.

NIMROD simulations of the IPA FRC experiment

NASA Astrophysics Data System (ADS)

Milroy, Richard

2015-11-01

The IPA experiment created a high temperature plasma by merging and compressing supersonic θ-pinch formed FRCs. The NIMROD code has been used to simulate this process. These calculations include the θ-pinch formation and acceleration of two FRC's using the dynamic formation methodology, and their translation to a central compression chamber where they merge and are magnetically compressed. Transport coefficients have been tuned so simulation results agree well with experimental observation. The inclusion of the Hall term is essential for the FRCs merge quickly, as observed experimentally through the excluded flux profiles. The inclusion of a significant anisotropic viscosity is required for the excluded flux profiles to agree well with the experiment. We plan to extend this validation work using the new ARPA-E funded Venti experiment at Helion Energy in Redmond WA. This will be a very well diagnosed experiment where two FRCs merge (like the IPA experiment) and are then compressed to near-fusion conditions. Preliminary calculations with parameters relevant to this experiment have been made, and some numerical issues identified.

A comparative study between experimental results and numerical predictions of multi-wall structural response to hypervelocity impact

NASA Technical Reports Server (NTRS)

Schonberg, William P.; Peck, Jeffrey A.

1992-01-01

Over the last three decades, multiwall structures have been analyzed extensively, primarily through experiment, as a means of increasing the protection afforded to spacecraft structure. However, as structural configurations become more varied, the number of tests required to characterize their response increases dramatically. As an alternative, numerical modeling of high-speed impact phenomena is often being used to predict the response of a variety of structural systems under impact loading conditions. This paper presents the results of a preliminary numerical/experimental investigation of the hypervelocity impact response of multiwall structures. The results of experimental high-speed impact tests are compared against the predictions of the HULL hydrodynamic computer code. It is shown that the hypervelocity impact response characteristics of a specific system cannot be accurately predicted from a limited number of HULL code impact simulations. However, if a wide range of impact loadings conditions are considered, then the ballistic limit curve of the system based on the entire series of numerical simulations can be used as a relatively accurate indication of actual system response.

Foundations of a query and simulation system for the modeling of biochemical and biological processes.

PubMed

Antoniotti, M; Park, F; Policriti, A; Ugel, N; Mishra, B

2003-01-01

The analysis of large amounts of data, produced as (numerical) traces of in vivo, in vitro and in silico experiments, has become a central activity for many biologists and biochemists. Recent advances in the mathematical modeling and computation of biochemical systems have moreover increased the prominence of in silico experiments; such experiments typically involve the simulation of sets of Differential Algebraic Equations (DAE), e.g., Generalized Mass Action systems (GMA) and S-systems. In this paper we reason about the necessary theoretical and pragmatic foundations for a query and simulation system capable of analyzing large amounts of such trace data. To this end, we propose to combine in a novel way several well-known tools from numerical analysis (approximation theory), temporal logic and verification, and visualization. The result is a preliminary prototype system: simpathica/xssys. When dealing with simulation data simpathica/xssys exploits the special structure of the underlying DAE, and reduces the search space in an efficient way so as to facilitate any queries about the traces. The proposed system is designed to give the user possibility to systematically analyze and simultaneously query different possible timed evolutions of the modeled system.

Space station definitions, design, and development. Task 5: Multiple arm telerobot coordination and control: Manipulator design methodology

NASA Technical Reports Server (NTRS)

Stoughton, R. M.

1990-01-01

A proposed methodology applicable to the design of manipulator systems is described. The current design process is especially weak in the preliminary design phase, since there is no accepted measure to be used in trading off different options available for the various subsystems. The design process described uses Cartesian End-Effector Impedance as a measure of performance for the system. Having this measure of performance, it is shown how it may be used to determine the trade-offs necessary to the preliminary design phase. The design process involves three main parts: (1) determination of desired system performance in terms of End-Effector Impedance; (2) trade-off design options to achieve this desired performance; and (3) verification of system performance through laboratory testing. The design process is developed using numerous examples and experiments to demonstrate the feasability of this approach to manipulator design.

Preliminary study of the effects of a reversible chemical reaction on gas bubble dissolution. [for space glass refining

NASA Technical Reports Server (NTRS)

Weinberg, M. C.

1982-01-01

A preliminary investigation is carried out of the effects of a reversible chemical reaction on the dissolution of an isolated, stationary gas bubble in a glass melt. The exact governing equations for the model system are formulated and analyzed. The approximate quasi-steady-state version of these equations is solved analytically, and a calculation is made of bubble dissolution rates. The results are then compared with numerical solutions obtained from the finite difference form of the exact governing equations. It is pointed out that in the microgravity condition of space, the buoyant rise of a gas bubble in a glass melt will be negligible on the time scale of most experiments. For this reason, a determination of the behavior of a stationary gas bubble in a melt is relevant for an understanding of glass refining in space.

Analysis of wind-blown sand movement over transverse dunes.

PubMed

Jiang, Hong; Huang, Ning; Zhu, Yuanjian

2014-12-01

Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand particle saltation. In this paper, we propose a numerical model for the coupling effect between wind flow and saltating sand particles to simulate wind-blown sand movement over the slope surface and use the SIMPLE algorithm to calculate wind flow and simulate sands transport by tracking sand particle trajectories. We furthermore compare the result of numerical simulation with wind tunnel experiments. These results prove that sand particles have obvious effect on wind flow, especially that over the leeward slope. This study is a preliminary study on windblown sand movement in a complex terrain, and is of significance in the control of dust storms and land desertification.

Analysis of Wind-blown Sand Movement over Transverse Dunes

PubMed Central

Jiang, Hong; Huang, Ning; Zhu, Yuanjian

2014-01-01

Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand particle saltation. In this paper, we propose a numerical model for the coupling effect between wind flow and saltating sand particles to simulate wind-blown sand movement over the slope surface and use the SIMPLE algorithm to calculate wind flow and simulate sands transport by tracking sand particle trajectories. We furthermore compare the result of numerical simulation with wind tunnel experiments. These results prove that sand particles have obvious effect on wind flow, especially that over the leeward slope. This study is a preliminary study on windblown sand movement in a complex terrain, and is of significance in the control of dust storms and land desertification. PMID:25434372

Towards monitoring real-time cellular response using an integrated microfluidics-MALDI/nESI-ion mobility-mass spectrometry platform

PubMed Central

Enders, Jeffrey R.; Marasco, Christina C.; Kole, Ayeeshik; Nguyen, Bao; Sundarapandian, Sevugarajan; Seale, Kevin T.; Wikswo, John P.; McLean, John A.

2014-01-01

The combination of microfluidic cell trapping devices with ion mobility-mass spectrometry offers the potential for elucidating in real time the dynamic responses of small populations of cells to paracrine signals, changes in metabolite levels, and delivery of drugs and toxins. Preliminary experiments examining peptides in methanol and recording the interactions of yeast and Jurkat cells with their superfusate have identified instrumental setup and control parameters and on-line desalting procedures. Numerous initial experiments demonstrate and validate this new instrumental platform. Future outlooks and potential applications are addressed, specifically how this instrumentation may be used for fully automated systems biology studies of the significantly interdependent, dynamic internal workings of cellular metabolic and signaling pathways. PMID:21073240

Preliminary analysis of pilot ratings of 'part line' information importance

NASA Technical Reports Server (NTRS)

Pritchett, Amy; Hansman, R. John

1993-01-01

With the introduction of digital datalink communications into the Air Traffic Control (ATC) system, there is concern over the potential loss of situational awareness by flight crews due to the reduction in the 'Party Line Information' (PLI). This information is available to the pilot by overhearing communications between ATC and other aircraft. A survey was distributed to determine current PLI use by several pilot operational groups, experience levels and geographic regions. The survey identified numerous important elements. PLI was rated the highest for operations near or on approach to the airport. Several significant variations were found between pilots from different operational groups and experience levels. Traffic and weather information were the most frequently cited as information required to obtain global situation awareness.

Preliminary Analysis of Pilot Ratings of "Party Line" Information Importance

NASA Technical Reports Server (NTRS)

Pritchett, Amy; Hansman, R. John

1993-01-01

With the introduction of digital data link communications into the ATC system, there is concern over the potential loss of situational awareness by flight crews due to the reduction in the 'Party Line' Information (PLI). This information is available to the pilot by overhearing communications between ATC and other aircraft. A survey was distributed to determine current PLI use by several pilot operational groups, experience levels and geographic regions. The survey identified numerous important elements. PLI was rated the highest for operations near or on approach to the airport. Several significant variations were found between pilots from different operational groups and experience levels. Traffic and weather information were the most frequently cited as information required to obtain global situation awareness.

Swinging Atwood Machine: Experimental and numerical results, and a theoretical study

NASA Astrophysics Data System (ADS)

Pujol, O.; Pérez, J. P.; Ramis, J. P.; Simó, C.; Simon, S.; Weil, J. A.

2010-06-01

A Swinging Atwood Machine ( SAM) is built and some experimental results concerning its dynamic behaviour are presented. Experiments clearly show that pulleys play a role in the motion of the pendulum, since they can rotate and have non-negligible radii and masses. Equations of motion must therefore take into account the moment of inertia of the pulleys, as well as the winding of the rope around them. Their influence is compared to previous studies. A preliminary discussion of the role of dissipation is included. The theoretical behaviour of the system with pulleys is illustrated numerically, and the relevance of different parameters is highlighted. Finally, the integrability of the dynamic system is studied, the main result being that the machine with pulleys is non-integrable. The status of the results on integrability of the pulley-less machine is also recalled.

The Windy Island Soliton Experiment (WISE): Shallow Water and Basin Experiment Configuration and Preliminary Observations

DTIC Science & Technology

2009-02-19

Virginia 22203-1995 The Windy Island Soliton Experiment (WISE): Shallow Water and Basin Experiment Configuration and Preliminary Observations...case letters) The Windy Island Soliton Experiment (WISE): Shallow water and Basin Experiment Configuration and Preliminary Observations 5. FUNDING...release; distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) The Windy Islands Soliton Experiment (WISE) was

Shortest path problem on a grid network with unordered intermediate points

NASA Astrophysics Data System (ADS)

Saw, Veekeong; Rahman, Amirah; Eng Ong, Wen

2017-10-01

We consider a shortest path problem with single cost factor on a grid network with unordered intermediate points. A two stage heuristic algorithm is proposed to find a feasible solution path within a reasonable amount of time. To evaluate the performance of the proposed algorithm, computational experiments are performed on grid maps of varying size and number of intermediate points. Preliminary results for the problem are reported. Numerical comparisons against brute forcing show that the proposed algorithm consistently yields solutions that are within 10% of the optimal solution and uses significantly less computation time.

Reynolds-Averaged Navier-Stokes Studies of Low Reynolds Number Effects on the Losses in a Low Pressure Turbine

NASA Technical Reports Server (NTRS)

Dorney, Daniel J.

1996-01-01

Experimental data from jet-engine tests have indicated that unsteady blade-row interaction effects can have a significant impact on the efficiency of low-pressure turbine stages. Measured turbine efficiencies at takeoff can be as much as two points higher than those at cruise conditions. Preliminary studies indicate that Reynolds number effects may contribute to the lower efficiencies at cruise conditions. In the current study, numerical experiments have been performed to quantify the Reynolds number dependence of unsteady wake/separation bubble interaction on the performance of a low-pressure turbine.

A numerical study of the hot gas environment around a STOVL aircraft in ground proximity

NASA Technical Reports Server (NTRS)

Vanoverbeke, Thomas J.; Holdeman, James D.

1988-01-01

The development of Short Takeoff Vertical Landing (STOVL) aircraft has historically been an empirical- and experience-based technology. In this study, a 3-D turbulent flow CFD code was used to calculate the hot gas environment around an STOVL aircraft operating in ground proximity. Preliminary calculations are reported for a typical STOVL aircraft configuration to identify key features of the flow field, and to demonstrate and assess the capability of current 3-D CFD codes to calculate the temperature of the gases ingested at the engine inlet as a function of flow and geometric conditions.

Influence of Controlled Viscous Dissipation on Propagation of Strongly Nonlinear Waves in Steel-Based Phononic Crystals

NASA Astrophysics Data System (ADS)

Herbold, Eric

2005-07-01

Strongly nonlinear phononic crystals were assembled from chains of stainless steel spheres with diameter 4.78 mm. Propagation of solitary waves and splitting of initial pulse into train of solitary waves excited by the impact of piston was investigated in different viscous media in experiments and in numerical calculations. Oil of various grades was used to introduce controlled dissipation into the system. Preliminary results indicate that splitting of the initial pulse into the train of solitary waves was dramatically influenced by viscosity. This work was supported by NSF (Grant No. DCMS03013220).

Daily Life Experience and Somatic Symptoms: A Preliminary Report.

DTIC Science & Technology

1981-03-01

AAO7 9 859 STATE UNIV OF NEW YORK AT STONY BROOK FG 5/10 DAILY LIFE EXPERIENCE AND SOMATIC SYMPTOMS: A PRELIMINARY REPOR--ETC(U) MAR 8I A A STONE. J...Experience and Somatic Symptoms: A Preliminary Report Arthur A. Stone Long Island Research Institute and Department of Psychiatry arnd Behavioral...TITLE (and S..,til.) s. ALF - , rlA9OQ COVERED Daily Life Experience and Somatic Symptoms: A Technical p " Preliminary Report, EL..... S. PERFORMING

Experimental apparatus with full optical access for combustion experiments with laminar flames from a single circular nozzle at elevated pressures.

PubMed

Joo, Peter H; Gao, Jinlong; Li, Zhongshan; Aldén, Marcus

2015-03-01

The design and features of a high pressure chamber and burner that is suitable for combustion experiments at elevated pressures are presented. The high pressure combustion apparatus utilizes a high pressure burner that is comprised of a chamber burner module and an easily accessible interchangeable burner module to add to its flexibility. The burner is well suited to study both premixed and non-premixed flames. The optical access to the chamber is provided through four viewports for direct visual observations and optical-based diagnostic techniques. Auxiliary features include numerous access ports and electrical connections and as a result, the combustion apparatus is also suitable to work with plasmas and liquid fuels. Images of methane flames at elevated pressures up to 25 atm and preliminary results of optical-based measurements demonstrate the suitability of the high pressure experimental apparatus for combustion experiments.

Aerodynamic design of the contoured wind-tunnel liner for the NASA supercritical, laminar-flow-control, swept-wing experiment

NASA Technical Reports Server (NTRS)

Newman, P. A.; Anderson, E. C.; Peterson, J. B., Jr.

1984-01-01

An overview is presented of the entire procedure developed for the aerodynamic design of the contoured wind tunnel liner for the NASA supercritical, laminar flow control (LFC), swept wing experiment. This numerical design procedure is based upon the simple idea of streamlining and incorporates several transonic and boundary layer analysis codes. The liner, presently installed in the Langley 8 Foot Transonic Pressure Tunnel, is about 54 ft long and extends from within the existing contraction cone, through the test section, and into the diffuser. LFC model testing has begun and preliminary results indicate that the liner is performing as intended. The liner design results presented in this paper, however, are examples of the calculated requirements and the hardware implementation of them.

The runout of granular material: from analogue to numerical modelling

NASA Astrophysics Data System (ADS)

Longchamp, Celine; Caspar, Olivier; Gygax, Remo; Podladchikov, Yury; Jaboyedoff, Michel

2014-05-01

Rock avalanches are catastrophic events in which important granular rock masses (>106 m3) travel at velocities up to ten meters per second. The mobilized rock mass travel long distances, which in exceptional cases can reach up to tens of kilometers. Those highly destructive and uncontrollable events, give important insight to understand the interactions between the displaced masses and landscape conditions. However, as those events are not frequent, analogue and numerical modelling plays a fundamental role to better understand their behaviour. The objective of the research is to explore the propagation of rock avalanches and to compare a simple numerical model with analogue modelling. The laboratory experiments investigate the fluidlike flow of a granular mass down a slope. The flow is unconfined, following a 45° slope and spreading freely on a horizontal depositional surface. Different grainsize of calibrate material (115, 545 and 2605 μm) and substratum roughness (simulate by aluminium and sandpapers with grainsize from 16 to 425 μm) were used in order to understand their influence on the motion of a granular mass. High speed movies are recorded to analyse the behaviour of the mass during the whole experiment. The numerical model is based on the continuum mechanics approach and solving the shallow water equations. The avalanche is described from an eulerian point of view within a continuum framework as single phase of incompressible granular material following Mohr-Coulomb friction law. The combination of the fluid dynamic equation with the frictional law enables the self-channelization of the mass without any topographic constraints or special border conditions. The results obtained with the numerical model are similar to those observed with the analogue. In both cases, based on similar initial condition (slope, volume, basal friction, height of fall and initial velocity), the runout of the mass is of comparable size and the shape of the deposit matches well. This preliminary version of the code gives encouraging results in agreement with those obtained with laboratory experiments.

Efficient Simulation Budget Allocation for Selecting an Optimal Subset

NASA Technical Reports Server (NTRS)

Chen, Chun-Hung; He, Donghai; Fu, Michael; Lee, Loo Hay

2008-01-01

We consider a class of the subset selection problem in ranking and selection. The objective is to identify the top m out of k designs based on simulated output. Traditional procedures are conservative and inefficient. Using the optimal computing budget allocation framework, we formulate the problem as that of maximizing the probability of correc tly selecting all of the top-m designs subject to a constraint on the total number of samples available. For an approximation of this corre ct selection probability, we derive an asymptotically optimal allocat ion and propose an easy-to-implement heuristic sequential allocation procedure. Numerical experiments indicate that the resulting allocatio ns are superior to other methods in the literature that we tested, and the relative efficiency increases for larger problems. In addition, preliminary numerical results indicate that the proposed new procedur e has the potential to enhance computational efficiency for simulation optimization.

WEC3: Wave Energy Converter Code Comparison Project: Preprint

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

Combourieu, Adrien; Lawson, Michael; Babarit, Aurelien

This paper describes the recently launched Wave Energy Converter Code Comparison (WEC3) project and present preliminary results from this effort. The objectives of WEC3 are to verify and validate numerical modelling tools that have been developed specifically to simulate wave energy conversion devices and to inform the upcoming IEA OES Annex VI Ocean Energy Modelling Verification and Validation project. WEC3 is divided into two phases. Phase 1 consists of a code-to-code verification and Phase II entails code-to-experiment validation. WEC3 focuses on mid-fidelity codes that simulate WECs using time-domain multibody dynamics methods to model device motions and hydrodynamic coefficients to modelmore » hydrodynamic forces. Consequently, high-fidelity numerical modelling tools, such as Navier-Stokes computational fluid dynamics simulation, and simple frequency domain modelling tools were not included in the WEC3 project.« less

Local Discontinuous Galerkin Methods for Partial Differential Equations with Higher Order Derivatives

NASA Technical Reports Server (NTRS)

Yan, Jue; Shu, Chi-Wang; Bushnell, Dennis M. (Technical Monitor)

2002-01-01

In this paper we review the existing and develop new continuous Galerkin methods for solving time dependent partial differential equations with higher order derivatives in one and multiple space dimensions. We review local discontinuous Galerkin methods for convection diffusion equations involving second derivatives and for KdV type equations involving third derivatives. We then develop new local discontinuous Galerkin methods for the time dependent bi-harmonic type equations involving fourth derivatives, and partial differential equations involving fifth derivatives. For these new methods we present correct interface numerical fluxes and prove L(exp 2) stability for general nonlinear problems. Preliminary numerical examples are shown to illustrate these methods. Finally, we present new results on a post-processing technique, originally designed for methods with good negative-order error estimates, on the local discontinuous Galerkin methods applied to equations with higher derivatives. Numerical experiments show that this technique works as well for the new higher derivative cases, in effectively doubling the rate of convergence with negligible additional computational cost, for linear as well as some nonlinear problems, with a local uniform mesh.

A field investigation and numerical simulation of coastal fog

NASA Technical Reports Server (NTRS)

Mack, E. J.; Eadie, W. J.; Rogers, C. W.; Kocmond, W. C.; Pilie, R. J.

1973-01-01

A field investigation of the microphysical and micrometeorological features of fogs occurring near Los Angeles and Vandenberg, California was conducted. Observations of wind speed and direction, temperature, dew point, vertical wind velocity, dew deposition, drop-size distribution, liquid water content, and haze and cloud nucleus concentration were obtained. These observations were initiated in late evening prior to fog formation and continued until the time of dissipation in both advection and radiation fogs. Data were also acquired in one valley fog and several dense haze situations. The behavior of these parameters prior to and during fog are discussed in detail. A two-dimensional numerical model was developed to investigate the formation and dissipation of advection fogs under the influence of horizontal variations in surface temperature. The model predicts the evolution of potential temperature, water vapor content, and liquid water content in a vertical plane as determined by vertical turbulent transfer and horizontal advection. Results are discussed from preliminary numerical experiments on the formation of warm-air advection fog and dissipation by natural and artificial heating from the surface.

A microkernel design for component-based parallel numerical software systems.

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

Balay, S.

1999-01-13

What is the minimal software infrastructure and what type of conventions are needed to simplify development of sophisticated parallel numerical application codes using a variety of software components that are not necessarily available as source code? We propose an opaque object-based model where the objects are dynamically loadable from the file system or network. The microkernel required to manage such a system needs to include, at most: (1) a few basic services, namely--a mechanism for loading objects at run time via dynamic link libraries, and consistent schemes for error handling and memory management; and (2) selected methods that all objectsmore » share, to deal with object life (destruction, reference counting, relationships), and object observation (viewing, profiling, tracing). We are experimenting with these ideas in the context of extensible numerical software within the ALICE (Advanced Large-scale Integrated Computational Environment) project, where we are building the microkernel to manage the interoperability among various tools for large-scale scientific simulations. This paper presents some preliminary observations and conclusions from our work with microkernel design.« less

A characteristics-based method for solving the transport equation and its application to the process of mantle differentiation and continental root growth

NASA Astrophysics Data System (ADS)

de Smet, Jeroen H.; van den Berg, Arie P.; Vlaar, Nico J.; Yuen, David A.

2000-03-01

Purely advective transport of composition is of major importance in the Geosciences, and efficient and accurate solution methods are needed. A characteristics-based method is used to solve the transport equation. We employ a new hybrid interpolation scheme, which allows for the tuning of stability and accuracy through a threshold parameter ɛth. Stability is established by bilinear interpolations, and bicubic splines are used to maintain accuracy. With this scheme, numerical instabilities can be suppressed by allowing numerical diffusion to work in time and locally in space. The scheme can be applied efficiently for preliminary modelling purposes. This can be followed by detailed high-resolution experiments. First, the principal effects of this hybrid interpolation method are illustrated and some tests are presented for numerical solutions of the transport equation. Second, we illustrate that this approach works successfully for a previously developed continental evolution model for the convecting upper mantle. In this model the transport equation contains a source term, which describes the melt production in pressure-released partial melting. In this model, a characteristic phenomenon of small-scale melting diapirs is observed (De Smet et al.1998; De Smet et al. 1999). High-resolution experiments with grid cells down to 700m horizontally and 515m vertically result in highly detailed observations of the diapiric melting phenomenon.

The Water-Mist Fire Suppression Experiment (Mist): Preliminary Results From The STS-107 Mission

NASA Technical Reports Server (NTRS)

Abbud-Madrid, Angel; McKinnon, J. Thomas; Amon, Francine; Gokoglu, Suleyman

2003-01-01

An investigation of the effect of water mists on premixed flame propagation has been conducted onboard the Space Shuttle to take advantage of the prolonged microgravity environment to study the effect of uniformly distributed clouds of polydisperse water mists on the speed and shape of propagating propane-air premixed flames. The suspension of a quiescent and uniform water mist cloud was confirmed during the microgravity tests. Preliminary results show good agreement with trends obtained by the numerical predictions of a computational model that uses a hybrid Eulerian-Lagrangian formulation to simulate the two-phase, flame/mist interaction. Effective flame suppression is observed at progressively higher water loadings and smaller water droplet sizes. Other unusual flame behavior, such as flame front breakup and pulsating flames, is still under investigation. The promising results from the microgravity tests will be used to assess the feasibility of using water mists as fire suppressants on Earth and on spacecraft.

Low Order Modeling Tools for Preliminary Pressure Gain Combustion Benefits Analyses

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.

2012-01-01

Pressure gain combustion (PGC) offers the promise of higher thermodynamic cycle efficiency and greater specific power in propulsion and power systems. This presentation describes a model, developed under a cooperative agreement between NASA and AFRL, for preliminarily assessing the performance enhancement and preliminary size requirements of PGC components either as stand-alone thrust producers or coupled with surrounding turbomachinery. The model is implemented in the Numerical Propulsion Simulation System (NPSS) environment allowing various configurations to be examined at numerous operating points. The validated model is simple, yet physics-based. It executes quickly in NPSS, yet produces realistic results.

Porting a Hall MHD Code to a Graphic Processing Unit

NASA Technical Reports Server (NTRS)

Dorelli, John C.

2011-01-01

We present our experience porting a Hall MHD code to a Graphics Processing Unit (GPU). The code is a 2nd order accurate MUSCL-Hancock scheme which makes use of an HLL Riemann solver to compute numerical fluxes and second-order finite differences to compute the Hall contribution to the electric field. The divergence of the magnetic field is controlled with Dedner?s hyperbolic divergence cleaning method. Preliminary benchmark tests indicate a speedup (relative to a single Nehalem core) of 58x for a double precision calculation. We discuss scaling issues which arise when distributing work across multiple GPUs in a CPU-GPU cluster.

Comparison of penalty functions on a penalty approach to mixed-integer optimization

NASA Astrophysics Data System (ADS)

Francisco, Rogério B.; Costa, M. Fernanda P.; Rocha, Ana Maria A. C.; Fernandes, Edite M. G. P.

2016-06-01

In this paper, we present a comparative study involving several penalty functions that can be used in a penalty approach for globally solving bound mixed-integer nonlinear programming (bMIMLP) problems. The penalty approach relies on a continuous reformulation of the bMINLP problem by adding a particular penalty term to the objective function. A penalty function based on the `erf' function is proposed. The continuous nonlinear optimization problems are sequentially solved by the population-based firefly algorithm. Preliminary numerical experiments are carried out in order to analyze the quality of the produced solutions, when compared with other penalty functions available in the literature.

Numerical Modelling of Solitary Wave Experiments on Rubble Mound Breakwaters

NASA Astrophysics Data System (ADS)

Guler, H. G.; Arikawa, T.; Baykal, C.; Yalciner, A. C.

2016-12-01

Performance of a rubble mound breakwater protecting Haydarpasa Port, Turkey, has been tested under tsunami attack by physical model tests conducted at Port and Airport Research Institute (Guler et al, 2015). It is aimed to understand dynamic force of the tsunami by conducting solitary wave tests (Arikawa, 2015). In this study, the main objective is to perform numerical modelling of solitary wave tests in order to verify accuracy of the CFD model IHFOAM, developed in OpenFOAM environment (Higuera et al, 2013), by comparing results of the numerical computations with the experimental results. IHFOAM is the numerical modelling tool which is based on VARANS equations with a k-ω SST turbulence model including realistic wave generation, and active wave absorption. Experiments are performed using a Froude scale of 1/30, measuring surface elevation and flow velocity at several locations in the wave channel, and wave pressure around the crown wall of the breakwater. Solitary wave tests with wave heights of H=7.5 cm and H=10 cm are selected which represent the results of the experiments. The first test (H=7.5 cm) is the case that resulted in no damage whereas the second case (H=10 cm) resulted in total damage due to the sliding of the crown wall. After comparison of the preliminary results of numerical simulations with experimental data for both cases, it is observed that solitary wave experiments could be accurately modeled using IHFOAM focusing water surface elevations, flow velocities, and wave pressures on the crown wall of the breakwater (Figure, result of sim. at t=29.6 sec). ACKNOWLEDGEMENTSThe authors acknowledge developers of IHFOAM, further extend their acknowledgements for the partial supports from the research projects MarDiM, ASTARTE, RAPSODI, and TUBITAK 213M534. REFERENCESArikawa (2015) "Consideration of Characteristics of Pressure on Seawall by Solitary Waves Based on Hydraulic Experiments", Jour. of Japan. Soc. of Civ. Eng. Ser. B2 (Coast. Eng.), Vol 71, p I889-I894 Guler, Arikawa, Oei, Yalciner (2015) "Performance of Rubble Mound Breakwaters under Tsunami Attack, A Case Study: Haydarpasa Port, Istanbul, Turkey", Coast. Eng. 104, 43-53 Higuera, Lara, Losada (2013) "Realistic Wave Generation and Active Wave Absorption for Navier-Stokes Models, Application to OpenFOAM", Coast. Eng. 71, 102-118

Numerical simulations of the spread of floating passive tracer released at the Old Harry prospect

NASA Astrophysics Data System (ADS)

Bourgault, Daniel; Cyr, Frédéric; Dumont, Dany; Carter, Angela

2014-05-01

The Gulf of St Lawrence is under immediate pressure for oil and gas exploration, particularly at the Old Harry prospect. A synthesis of the regulatory process that has taken place over the last few years indicates that important societal decisions soon to be made by various ministries and environmental groups are going to be based on numerous disagreements between the private sector and government agencies. The review also shows that the regulatory process has taken place with a complete lack of independent oceanographic research. Yet, the Gulf of St Lawrence is a complex environment that has never been specifically studied for oil and gas exploitation. Motivated by this knowledge gap, preliminary numerical experiments are carried out where the spreading of a passive floating tracer released at Old Harry is examined. Results indicate that the tracer released at Old Harry may follow preferentially two main paths. The first path is northward along the French Shore of Newfoundland, and the second path is along the main axis of the Laurentian Channel. The most probable coastlines to be touched by water flowing through Old Harry are Cape Breton and the southern portion of the French Shore, especially Cape Anguille and the Port au Port Peninsula. The Magdalen Islands are less susceptible to being affected than those regions but the probability is not negligible. These preliminary results provide guidance for future more in-depth and complete multidisciplinary studies from which informed decision-making scenarios could eventually be made regarding the exploration and development of oil and gas at the Old Harry prospect in particular and, more generally, in the Gulf of St Lawrence.

Insights from Modeling the Integrated Climate, Biogeochemical Cycles, Human Activities and Their Interactions in the ACME Earth System Model

NASA Astrophysics Data System (ADS)

Leung, L. R.; Thornton, P. E.; Riley, W. J.; Calvin, K. V.

2017-12-01

Towards the goal of understanding the contributions from natural and managed systems to current and future greenhouse gas fluxes and carbon-climate and carbon-CO2 feedbacks, efforts have been underway to improve representations of the terrestrial, river, and human components of the ACME earth system model. Broadly, our efforts include implementation and comparison of approaches to represent the nutrient cycles and nutrient limitations on ecosystem production, extending the river transport model to represent sediment and riverine biogeochemistry, and coupling of human systems such as irrigation, reservoir operations, and energy and land use with the ACME land and river components. Numerical experiments have been designed to understand how terrestrial carbon, nitrogen, and phosphorus cycles regulate climate system feedbacks and the sensitivity of the feedbacks to different model treatments, examine key processes governing sediment and biogeochemistry in the rivers and their role in the carbon cycle, and exploring the impacts of human systems in perturbing the hydrological and carbon cycles and their interactions. This presentation will briefly introduce the ACME modeling approaches and discuss preliminary results and insights from numerical experiments that lay the foundation for improving understanding of the integrated climate-biogeochemistry-human system.

Transition from Ignition to Flame Growth under External Radiation in Three Dimensions (TIGER-3D)

NASA Technical Reports Server (NTRS)

Kashiwagi, Takashi; Nakamura, Yuji; Olson, Sandra L.; Mell, William

2004-01-01

This study focuses on localized ignition by external radiant flux and subsequent flame growth over thin polymeric materials (plastic and paper) in microgravity. Two transition stages were observed. The first transition stage covers the period from the onset of ignition to the formation of stabilized flame near the ignited area. This is followed by the second transition of the flame growth stage from the initial stabilized flame to sustained fire growth away from the ignited area. For the first stage, ignition experiments of thin PMMA sheets were conducted using a CO2 laser as an external source in the 10 s drop tower. The results of front side surface ignition and of backside surface ignition were observed. The effects of imposed flow velocity, sample thickness, and ambient oxygen concentration on ignition are obtained. Numerical study was conducted to investigate to understand and predict ignition behavior observed in the experiments. For the second stage, numerical study is being conducted to describe the effects of gravity on heat release rate of a PMMA sheet. The gravity level was varied from zero to normal gravity. The preliminary results show that the maximum heat release occurs at around 0.02 g.

Transition from Ignition to Flame Growth under External Radiation in 3D

NASA Technical Reports Server (NTRS)

Kashiwagi, Takashi; Nakamura, Yuji; Mell, William E.; Olson, Sandra L.

2004-01-01

This study focuses on localized ignition by external radiant flux and subsequent flame growth over thin polymeric materials (plastic and paper) in microgravity. Two transition stages were observed. The first transition stage covers the period from the onset of ignition to the formation of stabilized flame near the ignited area. This is followed by the second transition of the flame growth stage from the initial stabilized flame to sustained fire growth away from the ignited area. For the first stage, ignition experiments of thin PMMA sheets were conducted using a CO2 laser as an external source in the 10 s drop tower. The results of front side surface ignition and of backside surface ignition were observed. The effects of imposed flow velocity, sample thickness, and ambient oxygen concentration on ignition are obtained. Numerical study was conducted to investigate to understand and predict ignition behavior observed in the experiments. For the second stage, numerical study is being conducted to describe the effects of gravity on heat release rate of a PMMA sheet. The gravity level was varied from zero to normal gravity. The preliminary results show that the maximum heat release occurs at around 0.02 g.

MSFC integrated experiments preliminary report. [for the Skylab program

NASA Technical Reports Server (NTRS)

1974-01-01

Skylab experiments are described and their preliminary results are reported. The types of experiments described include medical, earth resources, space physics, space manufacturing, and spacecraft design.

Idealized Quasi-Linear Convective Storms Crossing Over Coastlines

NASA Astrophysics Data System (ADS)

Lombardo, K.

2015-12-01

As organized coastal convective storms develop over land and move over a coastal ocean, their storm-scale structures, intensity, and associated weather threats evolve. This study aims to identify and quantify the fundamental mechanisms controlling the evolution of coastal quasi-linear convective systems (QLCSs) as they move offshore, as well as characterize the environmental conditions that support a phase space of life cycles. Results from this work will contribute to the improved predictability of these potentially severe warm season storms. The current work uses the Cloud Model 1 (CM1; Bryan and Fritsch 2002) to systematically study the interaction between QLCSs and marine atmospheric boundary layers (MABLs) associated with the coastal ocean in an idealized numerical framework. The initial simulations are run in 2-dimensions, with a 250 m horizontal resolution and a vertical resolution ranging from 100 m in the lowest 3000 m stretched to 250 m at the top of the 20 km domain. All simulations use the Weisman-Klemp analytic sounding as the base-state sounding profile in conjunction with an RKW-type wind profile. To create a numerical environment representative of a coastal region, the western half of the 800 km domain is configured to represent a land surface, while the eastern half represents a water surface. A series of sensitivity experiments are conducted to explore the influence of sea surface temperature and the associated marine atmospheric boundary layer on coastal QLCSs. Sea surface temperature values are selected to represent values observed within the Mid-Atlantic Bight coastal waters during the warm season, ranging from 14oC ('early summer') to 23oC ('late summer'). The numerical MABL is allowed to develop in time through surface heat fluxes. This presentation will discuss preliminary results from the 'early summer' and 'late summer' SST sensitivity experiments. Preliminary simulations indicate that the 'early summer' QLCS moves more quickly than the 'late summer' storm once the systems are over the MABL. Differences in propagation speed will be discussed in the context of lifting mechanisms along the leading edge of the QLCSs. Differences in the intensity of the convection will be discussed as well.

Inguinal-scrotal hernias in young patients: is laparoscopic repair a possible answer? Preliminary results of a single-institution experience with a transabdominal preperitoneal approach.

PubMed

Agresta, F; Mazzarolo, G; Balbi, P; Bedin, N

2010-10-01

The laparoscopic trans-abdominal preperitoneal (TAPP) approach to inguinal hernia repair is well documented as an excellent choice in numerous studies, especially when conducted by an experienced surgeon. Its full list of specific indications is still under debate. Generally, the repair of scrotal hernias demands a higher level of experience on the part of the surgeon, irrespective of the applied surgical technique. In this report, we evaluate our preliminary experience of TAPP laparoscopic repair for inguinoscrotal hernias in young patients in a Community Hospital setting, focusing on the feasibility of the technique and the incidence of complications. Between January 2008 and January 2009 a total of ten consecutive young patients at the "Civil Hospital" in Vittorio Veneto (TV), underwent TAPP laparoscopic repair of bilateral inguinoscrotal hernias. The overall mean operative time was 65 (+/-15) min. All procedures were performed on a day surgery basis. There were no conversions to open repair, no mortality/morbidity or relapsing hernias. The mean follow-up was 14 (+/-2) months. No patients reported severe pain at 10 days, There were no reports of night pain at 30 days. All patients had a return to physical-work capacity within 14 days. All patients were completely satisfied at the 3-month follow up. Analysis of the short-term post-operative outcomes of our experience enabled us to conclude that, in the proper setting, TAPP can be performed for inguinoscrotal hernia repair with an efficiency comparable to that of normal inguinal hernia repair.

Heat pipe dynamic behavior

NASA Technical Reports Server (NTRS)

Issacci, F.; Roche, G. L.; Klein, D. B.; Catton, I.

1988-01-01

The vapor flow in a heat pipe was mathematically modeled and the equations governing the transient behavior of the core were solved numerically. The modeled vapor flow is transient, axisymmetric (or two-dimensional) compressible viscous flow in a closed chamber. The two methods of solution are described. The more promising method failed (a mixed Galerkin finite difference method) whereas a more common finite difference method was successful. Preliminary results are presented showing that multi-dimensional flows need to be treated. A model of the liquid phase of a high temperature heat pipe was developed. The model is intended to be coupled to a vapor phase model for the complete solution of the heat pipe problem. The mathematical equations are formulated consistent with physical processes while allowing a computationally efficient solution. The model simulates time dependent characteristics of concern to the liquid phase including input phase change, output heat fluxes, liquid temperatures, container temperatures, liquid velocities, and liquid pressure. Preliminary results were obtained for two heat pipe startup cases. The heat pipe studied used lithium as the working fluid and an annular wick configuration. Recommendations for implementation based on the results obtained are presented. Experimental studies were initiated using a rectangular heat pipe. Both twin beam laser holography and laser Doppler anemometry were investigated. Preliminary experiments were completed and results are reported.

Analysis of Residual Acceleration Effects on Transport and Segregation During Directional Solidification of Tin-Bismuth in the MEPHISTO Furnace Facility

NASA Technical Reports Server (NTRS)

Alexander J. Iwan D. (Principal Investigator)

1996-01-01

The objective of this work is to approach the problem of determining the transport conditions (and effects of residual acceleration) during the plane-front directional solidification of a tin-bismuth alloy under low gravity conditions. The work involves using a combination of 2- and 3-D numerical models, scaling analyses, ID models and the results of ground-based and low-gravity experiments. The latter are to be conducted during the MEPHISTO experiment scheduled for USMP-3 in early 1996. The models will be used to predict the response of the transport conditions and consequent solute segregation in directionally solidifying tin-bismuth melt. Real-time Seebeck voltage variations across a Sn-Bi melt during directional solidification in MEPHISTO on USMP-1 show a distinct variation which can be correlated with thruster firings. The Seebeck voltage measurement is related to the response of the instantaneous average melt composition at the melt-solid interface. This allows a direct comparison of numerical simulations with the Seebeck signals obtained on USMP-1. The effects of such accelerations on composition for a directionally solidifying Sn-Bi alloy have been simulated numerically. USMP-1 acceleration data was used to assist in our choice of acceleration magnitude and orientation. The results show good agreement with experimental observations. The USMP-3 experiments took place earlier this year (February 22 through March 6). There were several differences between the USMP-3 experiments as compared to USMP-1. Firstly a more concentrated alloy was solidified and, secondly, Primary Reaction Control System thruster burns were requested at particular times during four separate growth runs. This allowed us to monitor the response Seebeck response under well-characterized growth conditions. In addition, we carried out simulations during the experiment in order to interpret the Seebeck signal. Preliminary results are described here.

Direct Numerical Simulation of A Shaped Hole Film Cooling Flow

NASA Astrophysics Data System (ADS)

Oliver, Todd; Moser, Robert

2015-11-01

The combustor exit temperatures in modern gas turbine engines are generally higher than the melting temperature of the turbine blade material. Film cooling, where cool air is fed through holes in the turbine blades, is one strategy which is used extensively in such engines to reduce heat transfer to the blades and thus reduce their temperature. While these flows have been investigated both numerically and experimentally, many features are not yet well understood. For example, the geometry of the hole is known to have a large impact on downstream cooling performance. However, the details of the flow in the hole, particularly for geometries similar to those used in practice, are generally know well-understood, both because it is difficult to experimentally observe the flow inside the hole and because much of the numerical literature has focused on round hole simulations. In this work, we show preliminary direct numerical simulation results for a film cooling flow passing through a shaped hole into a the boundary layer developing on a flat plate. The case has density ratio 1.6, blowing ratio 2.0, and the Reynolds number (based on momentum thickness) of incoming boundary layer is approximately 600. We compare the new simulations against both previous experiments and LES.

Numerical aerodynamic simulation facility preliminary study: Executive study

NASA Technical Reports Server (NTRS)

1977-01-01

A computing system was designed with the capability of providing an effective throughput of one billion floating point operations per second for three dimensional Navier-Stokes codes. The methodology used in defining the baseline design, and the major elements of the numerical aerodynamic simulation facility are described.

Studies of the nucler equation of state using numerical calculations of nuclear drop collisions

NASA Technical Reports Server (NTRS)

Alonso, C. T.; Leblanc, J. M.; Wilson, J. R.

1982-01-01

A numerical calculation for the full thermal dynamics of colliding nuclei was developed. Preliminary results are reported for the thermal fluid dynamics in such processes as Coulomb scattering, fusion, fusion-fission, bulk oscillations, compression with heating, and collisions of heated nuclei.

Characterizing the 21-cm absorption trough with pattern recognition and a numerical sampler

NASA Astrophysics Data System (ADS)

Tauscher, Keith A.; Rapetti, David; Burns, Jack O.; Monsalve, Raul A.; Bowman, Judd D.

2018-06-01

The highly redshifted sky-averaged 21-cm spectrum from neutral hydrogen is a key probe to a period of the Universe never before studied. Recent experimental advances have led to increasingly tightened constraints and the Experiment to Detect the Global Eor Signal (EDGES) has presented evidence for a detection of this global signal. In order to glean scientifically valuable information from these new measurements in a consistent manner, sophisticated fitting procedures must be applied. Here, I present a pipeline known as pylinex which takes advantage of Singular Value Decomposition (SVD), a pattern recognition tool, to leverage structure in the data induced by the design of an experiment to fit for signals in the experiment's data in the presence of large systematics (such as the beam-weighted foregrounds), especially those without parametric forms. This method requires training sets for each component of the data. Once the desired signal is extracted in SVD eigenmode coefficient space, the posterior distribution must be consistently transformed into a physical parameter space. This is done with the combination of a numerical least squares fitter and a Markov Chain Monte Carlo (MCMC) distribution sampler. After describing the pipeline's procedures and techniques, I present preliminary results of applying it to the EDGES low-band data used for their detection. The results include estimates of the signal in frequency space with errors and relevant parameter distributions.

Laboratory Experiments on Rotation and Alignment of the Analogs of Interstellar Dust Grains by Radiation

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; Gallagher, D. L.; West, E. A.; Weingartner, J. C.; Witherow, W. K.; Tielens, A. G. G. M.

2004-01-01

The processes and mechanisms involved in the rotation and alignment of interstellar dust grains have been of great interest in astrophysics ever since the surprising discovery of the polarization of starlight more than half a century ago. Numerous theories, detailed mathematical models, and numerical studies of grain rotation and alignment with respect to the Galactic magnetic field have been presented in the literature. In particular, the subject of grain rotation and alignment by radiative torques has been shown to be of particular interest in recent years. However, despite many investigations, a satisfactory theoretical understanding of the processes involved in subject, we have carried out some unique experiments to illuminate the processes involved in the rotation of dust grains in the interstellar medium. In this paper we present the results of some preliminary laboratory experiments on the rotation of individual micron/submicron-sized, nonspherical dust grains levitated in an electrodynamic balance evacuated to pressures of approximately 10(exp -3) to 10(exp -5) torr. The particles are illuminated by laser light at 5320 A, and the grain rotation rates are obtained by analyzing the low-frequency (approximately 0 - 100 kHz) signal of the scattered light detected by a photodiode detector. The rotation rates are compared with simple theoretical models to retrieve some basic rotational parameters. The results are examined in light of the current theories of alignment.

Preliminary results of the scientific experiments on the Kosmos-936 biosatellite

NASA Technical Reports Server (NTRS)

1977-01-01

The scientific equipment and experiments on the Kosmos-936 biosatellite are described, including various ground controls and the lab unit for studies at the descent vehicle landing site. Preliminary results are presented of the physiological experiment with rats, biological experiments with drosophila and higher and lower plants, and radiation physics and radiobiology studies for the planning of biological protection on future space flights. The most significant conclusion from the preliminary data is that rats tolerate space flight better with an artificial force of gravity.

Preliminary study for a numerical aerodynamic simulation facility. Phase 1: Extension

NASA Technical Reports Server (NTRS)

Lincoln, N. R.

1978-01-01

Functional requirements and preliminary design data were identified for use in the design of all system components and in the construction of a facility to perform aerodynamic simulation for airframe design. A skeleton structure of specifications for the flow model processor and monitor, the operating system, and the language and its compiler is presented.

Development and Preliminary Evaluation of a One-Week Summer Treatment Program for Separation Anxiety Disorder

ERIC Educational Resources Information Center

Santucci, Lauren C.; Ehrenreich, Jill T.; Trosper, Sarah E.; Bennett, Shannon M.; Pincus, Donna B.

2009-01-01

Numerous clinical trials have demonstrated the efficacy of cognitive behavior therapy (CBT) for the treatment of childhood Separation Anxiety Disorder (SAD) and other anxiety disorders yet additional research may still be needed to better access and engage anxious youth. In this study, we investigated the acceptability and preliminary utility of a…

Simulation of Ejecta Production and Mixing Process of Sn Sample under shock loading

NASA Astrophysics Data System (ADS)

Wang, Pei; Chen, Dawei; Sun, Haiquan; Ma, Dongjun

2017-06-01

Ejection may occur when a strong shock wave release at the free surface of metal material and the ejecta of high-speed particulate matter will be formed and further mixed with the surrounding gas. Ejecta production and its mixing process has been one of the most difficult problems in shock physics remain unresolved, and have many important engineering applications in the imploding compression science. The present paper will introduce a methodology for the theoretical modeling and numerical simulation of the complex ejection and mixing process. The ejecta production is decoupled with the particle mixing process, and the ejecta state can be achieved by the direct numerical simulation for the evolution of initial defect on the metal surface. Then the particle mixing process can be simulated and resolved by a two phase gas-particle model which uses the aforementioned ejecta state as the initial condition. A preliminary ejecta experiment of planar Sn metal Sample has validated the feasibility of the proposed methodology.

Krylov Deferred Correction Accelerated Method of Lines Transpose for Parabolic Problems

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

Jia, Jun; Jingfang, Huang

2008-01-01

In this paper, a new class of numerical methods for the accurate and efficient solutions of parabolic partial differential equations is presented. Unlike traditional method of lines (MoL), the new {\\bf \\it Krylov deferred correction (KDC) accelerated method of lines transpose (MoL^T)} first discretizes the temporal direction using Gaussian type nodes and spectral integration, and symbolically applies low-order time marching schemes to form a preconditioned elliptic system, which is then solved iteratively using Newton-Krylov techniques such as Newton-GMRES or Newton-BiCGStab method. Each function evaluation in the Newton-Krylov method is simply one low-order time-stepping approximation of the error by solving amore » decoupled system using available fast elliptic equation solvers. Preliminary numerical experiments show that the KDC accelerated MoL^T technique is unconditionally stable, can be spectrally accurate in both temporal and spatial directions, and allows optimal time-step sizes in long-time simulations.« less

Numerical Simulation of Roughness-Induced Transient Growth in a Laminar Boundary Layer

NASA Technical Reports Server (NTRS)

Fischer, Paul; Choudhari, Meelan

2004-01-01

Numerical simulations are used to examine the roughness-induced transient growth in a laminar boundary-layer flow. Based on the spectral element method, these simulations model the stationary disturbance field associated with a nonsmooth roughness geometry, such as the spanwise periodic array of circular disks used by White and co-workers during a series of wind tunnel experiments at Case Western Reserve University. Besides capturing the major trends from the recent measurements by White and Ergin, the simulations provide additional information concerning the relative accuracy of the experimental findings derived from two separate wall-finding procedures. The paper also explores the dependence of transient growth on geometric characteristics of the roughness distribution, including the height and planform shape of the roughness element and the ratio of roughness due to spacing between an adjacent pair of elements. Results are used for a preliminary assessment of the differences between recently reported theoretical results of Tumin and Reshotko and the measurements by White and Ergin.

NSR&D FY17 Report: CartaBlanca Capability Enhancements

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

Long, Christopher Curtis; Dhakal, Tilak Raj; Zhang, Duan Zhong

Over the last several years, particle technology in the CartaBlanca code has been matured and has been successfully applied to a wide variety of physical problems. It has been shown that the particle methods, especially Los Alamos's dual domain material point method, is capable of computing many problems involves complex physics, chemistries accompanied by large material deformations, where the traditional finite element or Eulerian method encounter significant difficulties. In FY17, the CartaBlanca code has been enhanced with physical models and numerical algorithms. We started out to compute penetration and HE safety problems. Most of the year we focused on themore » TEPLA model improvement testing against the sweeping wave experiment by Gray et al., because it was found that pore growth and material failure are essentially important for our tasks and needed to be understood for modeling the penetration and the can experiments efficiently. We extended the TEPLA mode from the point view of ensemble phase average to include the effects of nite deformation. It is shown that the assumed pore growth model in TEPLA is actually an exact result from the theory. Alone this line, we then generalized the model to include finite deformations to consider nonlinear dynamics of large deformation. The interaction between the HE product gas and the solid metal is based on the multi-velocity formation. Our preliminary numerical results suggest good agreement between the experiment and the numerical results, pending further verification. To improve the parallel processing capabilities of the CartaBlanca code, we are actively working with the Next Generation Code (NGC) project to rewrite selected packages using C++. This work is expected to continue in the following years. This effort also makes the particle technology developed with CartaBlanca project available to other part of the laboratory. Working with the NGC project and rewriting some parts of the code also given us an opportunity to improve our numerical implementations of the method and to take advantage of recently advances in the numerical methods, such as multiscale algorithms.« less

PAR -- Interface to the ADAM Parameter System

NASA Astrophysics Data System (ADS)

Currie, Malcolm J.; Chipperfield, Alan J.

PAR is a library of Fortran subroutines that provides convenient mechanisms for applications to exchange information with the outside world, through input-output channels called parameters. Parameters enable a user to control an application's behaviour. PAR supports numeric, character, and logical parameters, and is currently implemented only on top of the ADAM parameter system. The PAR library permits parameter values to be obtained, without or with a variety of constraints. Results may be put into parameters to be passed onto other applications. Other facilities include setting a prompt string, and suggested defaults. This document also introduces a preliminary C interface for the PAR library -- this may be subject to change in the light of experience.

Measurement data preprocessing in a radar-based system for monitoring of human movements

NASA Astrophysics Data System (ADS)

Morawski, Roman Z.; Miȩkina, Andrzej; Bajurko, Paweł R.

2015-02-01

The importance of research on new technologies that could be employed in care services for elderly people is highlighted. The need to examine the applicability of various sensor systems for non-invasive monitoring of the movements and vital bodily functions, such as heart beat or breathing rhythm, of elderly persons in their home environment is justified. An extensive overview of the literature concerning existing monitoring techniques is provided. A technological potential behind radar sensors is indicated. A new class of algorithms for preprocessing of measurement data from impulse radar sensors, when applied for elderly people monitoring, is proposed. Preliminary results of numerical experiments performed on those algorithms are demonstrated.

Numerical modeling of seismic anomalies at impact craters on a laboratory scale

NASA Astrophysics Data System (ADS)

Wuennemann, K.; Grosse, C. U.; Hiermaier, S.; Gueldemeister, N.; Moser, D.; Durr, N.

2011-12-01

Almost all terrestrial impact craters exhibit a typical geophysical signature. The usually observed circular negative gravity anomaly and reduced seismic velocities in the vicinity of crater structures are presumably related to an approximately hemispherical zone underneath craters where rocks have experienced intense brittle plastic deformation and fracturing during formation (see Fig.1). In the framework of the "MEMIN" (multidisciplinary experimental and modeling impact crater research network) project we carried out hypervelocity cratering experiments at the Fraunhofer Institute for High-Speed Dynamics on a decimeter scale to study the spatiotemporal evolution of the damage zone using ultrasound, acoustic emission techniques, and numerical modeling of crater formation. 2.5-10 mm iron projectiles were shot at 2-5.5 km/s on dry and water-saturated sandstone targets. The target material was characterized before, during and after the impact with high spatial resolution acoustic techniques to detect the extent of the damage zone, the state of rocks therein and to record the growth of cracks. The ultrasound measurements are applied analog to seismic surveys at natural craters but used on a different - i.e. much smaller - scale. We compare the measured data with dynamic models of crater formation, shock, plastic and elastic wave propagation, and tensile/shear failure of rocks in the impacted sandstone blocks. The presence of porosity and pore water significantly affects the propagation of waves. In particular the crushing of pores due to shock compression has to be taken into account. We present preliminary results showing good agreement between experiments and numerical model. In a next step we plan to use the numerical models to upscale the results from laboratory dimensions to the scale of natural impact craters.

Ring-fault activity at subsiding calderas studied from analogue experiments and numerical modeling

NASA Astrophysics Data System (ADS)

Liu, Y. K.; Ruch, J.; Vasyura-Bathke, H.; Jonsson, S.

2017-12-01

Several subsiding calderas, such as the ones in the Galápagos archipelago and the Axial seamount in the Pacific Ocean have shown a complex but similar ground deformation pattern, composed of a broad deflation signal affecting the entire volcanic edifice and of a localized subsidence signal focused within the caldera. However, it is still debated how deep processes at subsiding calderas, including magmatic pressure changes, source locations and ring-faulting, relate to this observed surface deformation pattern. We combine analogue sandbox experiments with numerical modeling to study processes involved from initial subsidence to later collapse of calderas. The sandbox apparatus is composed of a motor driven subsiding half-piston connected to the bottom of a glass box. During the experiments the observation is done by five digital cameras photographing from various perspectives. We use Photoscan, a photogrammetry software and PIVLab, a time-resolved digital image correlation tool, to retrieve time-series of digital elevation models and velocity fields from acquired photographs. This setup allows tracking the processes acting both at depth and at the surface, and to assess their relative importance as the subsidence evolves to a collapse. We also use the Boundary Element Method to build a numerical model of the experiment setup, which comprises contracting sill-like source in interaction with a ring-fault in elastic half-space. We then compare our results from these two approaches with the examples observed in nature. Our preliminary experimental and numerical results show that at the initial stage of magmatic withdrawal, when the ring-fault is not yet well formed, broad and smooth deflation dominates at the surface. As the withdrawal increases, narrower subsidence bowl develops accompanied by the upward propagation of the ring-faulting. This indicates that the broad deflation, affecting the entire volcano edifice, is primarily driven by the contraction of the magmatic source, whereas the ring-faulting tends to concentrate deformation within the caldera. This interaction between ring-faulting and pressure decrease in a magma reservoir therefore provides a possible explanation for the deformation pattern observed at several subsiding calderas.

Detection and Inspection of Steel Bars in Reinforced Concrete Structures Using Active Infrared Thermography with Microwave Excitation and Eddy Current Sensors

PubMed Central

Szymanik, Barbara; Frankowski, Paweł Karol; Chady, Tomasz; John Chelliah, Cyril Robinson Azariah

2016-01-01

The purpose of this paper is to present a multi-sensor approach to the detection and inspection of steel bars in reinforced concrete structures. In connection with our past experience related to non-destructive testing of different materials, we propose using two potentially effective methods: active infrared thermography with microwave excitation and the eddy current technique. In this article active infrared thermography with microwave excitation is analyzed both by numerical modeling and experiments. This method, based on thermal imaging, due to its characteriatics should be considered as a preliminary method for the assessment of relatively shallowly located steel bar reinforcements. The eddy current technique, on the other hand, allows for more detailed evaluation and detection of deeply located rebars. In this paper a series of measurement results, together with the initial identification of certain features of steel reinforcement bars will be presented. PMID:26891305

A designed experiment in stitched/RTM composites

NASA Technical Reports Server (NTRS)

Dickinson, Larry C.

1993-01-01

The damage tolerance of composite laminates can be significantly improved by the addition of through-the-thickness fibrous reinforcement such as stitching. However, there are numerous stitching parameters which can be independently varied, and their separate and combined effects on mechanical properties need to be determined. A statistically designed experiment (a 2(sup 5-1) fractional factorial, also known as a Taguchi L16 test matrix) used to evaluate five important parameters is described. The effects and interactions of stitch thread material, stitch thread strength, stitch row spacing and stitch pitch are examined for both thick (48 ply) and thin (16 ply) carbon/epoxy (AS4/E905L) composites. Tension, compression and compression after impact tests are described. Preliminary results of completed tension testing are discussed. Larger threads decreased tensile strength. Panel thickness was found not to be an important stitching parameter for tensile properties. Tensile modulus was unaffected by stitching.

Preliminary Observing System Simulation Experiments for Doppler Wind Lidars Deployed on the International Space Station

NASA Technical Reports Server (NTRS)

Kemp, E.; Jacob, J.; Rosenberg, R.; Jusem, J. C.; Emmitt, G. D.; Wood, S.; Greco, L. P.; Riishojgaard, L. P.; Masutani, M.; Ma, Z.;

Confinement effect on the dynamics of non-equilibrium concentration fluctuations far from the onset of convection.

PubMed

Giraudet, Cédric; Bataller, Henri; Sun, Yifei; Donev, Aleksandar; Ortiz de Zárate, José M; Croccolo, Fabrizio

2016-12-01

In a recent letter (C. Giraudet et al., EPL 111, 60013 (2015)) we reported preliminary data showing evidence of a slowing-down of non-equilibrium fluctuations of the concentration in thermodiffusion experiments on a binary mixture of miscible fluids. The reason for this slowing-down was attributed to the effect of confinement. Such tentative explanation is here experimentally corroborated by new measurements and theoretically substantiated by studying analytically and numerically the relevant fluctuating hydrodynamics equations. In the new experiments presented here, the magnitude of the temperature gradient is changed, confirming that the system is controlled solely by the solutal Rayleigh number, and that the slowing-down is dominated by a combined effect of the driving force of buoyancy, the dissipating force of diffusion and the confinement provided by the vertical extension of the sample cell. Moreover, a compact phenomenological interpolating formula is proposed for easy analysis of experimental results.

Modeling of Convective-Stratiform Precipitation Processes: Sensitivity to Partitioning Methods

NASA Technical Reports Server (NTRS)

Lang, S. E.; Tao, W.-K.; Simpson, J.; Ferrier, B.; Starr, David OC. (Technical Monitor)

2001-01-01

Six different convective-stratiform separation techniques, including a new technique that utilizes the ratio of vertical and terminal velocities, are compared and evaluated using two-dimensional numerical simulations of a tropical [Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment (TOGA COARE)] and midlatitude continental [Preliminary Regional Experiment for STORM-Central (PRESTORM)] squall line. Comparisons are made in terms of rainfall, cloud coverage, mass fluxes, apparent heating and moistening, mean hydrometeor profiles, CFADs (Contoured Frequency with Altitude Diagrams), microphysics, and latent heating retrieval. Overall, it was found that the different separation techniques produced results that qualitatively agreed. However, the quantitative differences were significant. Observational comparisons were unable to conclusively evaluate the performance of the techniques. Latent heating retrieval was shown to be sensitive to the use of separation technique mainly due to the stratiform region for methods that found very little stratiform rain.

Detection and Inspection of Steel Bars in Reinforced Concrete Structures Using Active Infrared Thermography with Microwave Excitation and Eddy Current Sensors.

PubMed

Szymanik, Barbara; Frankowski, Paweł Karol; Chady, Tomasz; John Chelliah, Cyril Robinson Azariah

2016-02-16

The purpose of this paper is to present a multi-sensor approach to the detection and inspection of steel bars in reinforced concrete structures. In connection with our past experience related to non-destructive testing of different materials, we propose using two potentially effective methods: active infrared thermography with microwave excitation and the eddy current technique. In this article active infrared thermography with microwave excitation is analyzed both by numerical modeling and experiments. This method, based on thermal imaging, due to its characteriatics should be considered as a preliminary method for the assessment of relatively shallowly located steel bar reinforcements. The eddy current technique, on the other hand, allows for more detailed evaluation and detection of deeply located rebars. In this paper a series of measurement results, together with the initial identification of certain features of steel reinforcement bars will be presented.

MODELING AND ANALYSIS OF FISSION PRODUCT TRANSPORT IN THE AGR-3/4 EXPERIMENT

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

Humrickhouse, Paul W.; Collin, Blaise P.; Hawkes, Grant L.

In this work we describe the ongoing modeling and analysis efforts in support of the AGR-3/4 experiment. AGR-3/4 is intended to provide data to assess fission product retention and transport (e.g., diffusion coefficients) in fuel matrix and graphite materials. We describe a set of pre-test predictions that incorporate the results of detailed thermal and fission product release models into a coupled 1D radial diffusion model of the experiment, using diffusion coefficients reported in the literature for Ag, Cs, and Sr. We make some comparisons of the predicted Cs profiles to preliminary measured data for Cs and find these to bemore » reasonable, in most cases within an order of magnitude. Our ultimate objective is to refine the diffusion coefficients using AGR-3/4 data, so we identify an analytical method for doing so and demonstrate its efficacy via a series of numerical experiments using the model predictions. Finally, we discuss development of a post-irradiation examination plan informed by the modeling effort and simulate some of the heating tests that are tentatively planned.« less

Preliminary Numerical and Experimental Analysis of the Spallation Phenomenon

NASA Technical Reports Server (NTRS)

Martin, Alexandre; Bailey, Sean C. C.; Panerai, Francesco; Davuluri, Raghava S. C.; Vazsonyi, Alexander R.; Zhang, Huaibao; Lippay, Zachary S.; Mansour, Nagi N.; Inman, Jennifer A.; Bathel, Brett F.;

IMC/RMC Network Professional Film Collection.

ERIC Educational Resources Information Center

New York State Education Dept., Albany. Special Education Instructional Materials Center.

The compilation is a comprehensive listing of films available from the centers in the Instructional Materials Centers/Regional Media Centers (IMC/RMC) Network. Each IMC/RMC location is given a numerical code in a preliminary listing. These numerical codes are used within the film listing, which is arranged alphabetically according to film titles,…

Numerical Simulations of Laser-Driven Microflyer Plates

NASA Astrophysics Data System (ADS)

Colvin, Jeffrey D.; Frank, Alan M.; Lee, Ronald S.; Remington, Bruce A.

2000-10-01

Experiments conducted in the US and France have accelerated few-micron-thick foils of aluminum to velocities of 3 - 5 km/s using 25 - 50 J/cm^2 of 1-μm laser light (1,2). These microflyer plates are not too dissimilar in size and velocity from interplanetary dust particles (3). We are performing numerical simulations of these experiments with the 2-D radiation-hydrodynamics code LASNEX (4), incorporating a model for low-fluence electromagnetic wave reflection and absorption in metals, with the objective of determining the physical processes important to optimizing the flyer design. We will discuss our preliminary findings, including the efficacy of a thermal insulation layer and the role played by the substrate on which the flyer is mounted. (1) W.M. Trott, R.E. Setchell, and A.V. Farnsworth, Jr., in Shock Compression of Condensed Matter-1999, ed. M.D. Furnish, L.C. Chhabildas, and R.S. Hixson, AIP, 2000, pp. 1203-06. (2) J. L. Labaste, M. Doucet, and P. Joubert, in Shock Compression of Condensed Matter-1995, ed. S.C. Schmidt and W.C. Tao, AIP, 1996, pp. 1221-24. (3) W.W. Anderson and T.J. Ahrens, J. Geophys. Res. 99, 2063 (1994). (4) G. B. Zimmerman and W. L. Kruer, Comments Plasma Phys. Controlled Fusion 2, 51 (1975).

Dependence of residual displacements on the width and depth of compliant fault zones: a 3D study

NASA Astrophysics Data System (ADS)

Kang, J.; Duan, B.

2011-12-01

Compliant fault zones have been detected along active faults by seismic investigations (trapped waves and travel time analysis) and InSAR observations. However, the width and depth extent of compliant fault zones are still under debate in the community. Numerical models of dynamic rupture build a bridge between theories and the geological and geophysical observations. Theoretical 2D plane-strain studies of elastic and inelastic response of compliant fault zones to nearby earthquake have been conducted by Duan [2010] and Duan et al [2010]. In this study, we further extend the experiments to 3D with a focus on elastic response. We are specifically interested in how residual displacements depend on the structure and properties of complaint fault zones, in particular on the width and depth extent. We conduct numerical experiments on various types of fault-zone models, including fault zones with a constant width along depth, with decreasing widths along depth, and with Hanning taper profiles of velocity reduction. . Our preliminary results suggest 1) the width of anomalous horizontal residual displacement is only indicative of the width of a fault zone near the surface, and 2) the vertical residual displacement contains information of the depth extent of compliant fault zones.

A 160 kJ dual plasma focus (DuPF) for fusion-relevant materials testing and nano-materials fabrication

NASA Astrophysics Data System (ADS)

Saw, S. H.; Damideh, V.; Chong, P. L.; Lee, P.; Rawat, R. S.; Lee, S.

2014-08-01

This paper summarizes PF-160 Dual Plasma Focus (DuPF) numerical experiments using the Lee Model code and preliminary 3D design drawings using SolidWorks software. This DuPF consists of two interchangeable electrodes enabling it to be optimized for both Slow Pinch Mode (SFM) and Fast Pinch Mode (FFM); the latter using a speed factor (SF) of 90 kA cm-1 Torr-0.5 for FFM in deuterium [S Lee et al, IEEE Trans Plasma Science 24, 1101-1105 (1996)]; and the former with SF of less than half that value for SFM. Starting with available 6 × 450 µF capacitors rated at 11kV (10% reversal), numerical experiments indicate safe operation at 9 kV, 6 Torr deuterium with FFM anode of 5 cm radius; producing intense ion beam and streaming plasma pulses which would be useful for studies of potential fusion reactor wall materials. On the other hand operating at 5 kV, 10 Torr deuterium with SFM anode of 10 cm radius leads to long-duration, uniform large-area flow which could be more suitable for synthesis of nano-materials. The dual plasma focus design is illustrated here with two figures showing FFM and SFM electrodes.

Calculating the metabolizable energy of macronutrients: a critical review of Atwater's results.

PubMed

Sánchez-Peña, M Judith; Márquez-Sandoval, Fabiola; Ramírez-Anguiano, Ana C; Velasco-Ramírez, Sandra F; Macedo-Ojeda, Gabriela; González-Ortiz, Luis J

2017-01-01

The current values for metabolizable energy of macronutrients were proposed in 1910. Since then, however, efforts to revise these values have been practically absent, creating a crucial need to carry out a critical analysis of the experimental methodology and results that form the basis of these values. Presented here is an exhaustive analysis of Atwater's work on this topic, showing evidence of considerable weaknesses that compromise the validity of his results. These weaknesses include the following: (1) the doubtful representativeness of Atwater's subjects, their activity patterns, and their diets; (2) the extremely short duration of the experiments; (3) the uncertainty about which fecal and urinary excretions contain the residues of each ingested food; (4) the uncertainty about whether or not the required nitrogen balance in individuals was reached during experiments; (5) the numerous experiments carried out without valid preliminary experiments; (6) the imprecision affecting Atwater's experimental measurements; and (7) the numerous assumptions and approximations, along with the lack of information, characterizing Atwater's studies. This review presents specific guidelines for establishing new experimental procedures to estimate more precise and/or more accurate values for the metabolizable energy of macronutrients. The importance of estimating these values in light of their possible dependence on certain nutritional parameters and/or physical activity patterns of individuals is emphasized. The use of more precise values would allow better management of the current overweight and obesity epidemic. © The Author(s) 2016. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Asymptotic analysis of dissipative waves with applications to their numerical simulation

NASA Technical Reports Server (NTRS)

Hagstrom, Thomas

1990-01-01

Various problems involving the interplay of asymptotics and numerics in the analysis of wave propagation in dissipative systems are studied. A general approach to the asymptotic analysis of linear, dissipative waves is developed. It was applied to the derivation of asymptotic boundary conditions for numerical solutions on unbounded domains. Applications include the Navier-Stokes equations. Multidimensional traveling wave solutions to reaction-diffusion equations are also considered. A preliminary numerical investigation of a thermo-diffusive model of flame propagation in a channel with heat loss at the walls is presented.

STEP Experiment Requirements

NASA Technical Reports Server (NTRS)

Brumfield, M. L. (Compiler)

1984-01-01

A plan to develop a space technology experiments platform (STEP) was examined. NASA Langley Research Center held a STEP Experiment Requirements Workshop on June 29 and 30 and July 1, 1983, at which experiment proposers were invited to present more detailed information on their experiment concept and requirements. A feasibility and preliminary definition study was conducted and the preliminary definition of STEP capabilities and experiment concepts and expected requirements for support services are presented. The preliminary definition of STEP capabilities based on detailed review of potential experiment requirements is investigated. Topics discussed include: Shuttle on-orbit dynamics; effects of the space environment on damping materials; erectable beam experiment; technology for development of very large solar array deployers; thermal energy management process experiment; photovoltaic concentrater pointing dynamics and plasma interactions; vibration isolation technology; flight tests of a synthetic aperture radar antenna with use of STEP.

Numerical simulation of cavitating flows in shipbuilding

NASA Astrophysics Data System (ADS)

Bagaev, D.; Yegorov, S.; Lobachev, M.; Rudnichenko, A.; Taranov, A.

2018-05-01

The paper presents validation of numerical simulations of cavitating flows around different marine objects carried out at the Krylov State Research Centre (KSRC). Preliminary validation was done with reference to international test objects. The main part of the paper contains results of solving practical problems of ship propulsion design. The validation of numerical simulations by comparison with experimental data shows a good accuracy of the supercomputer technologies existing at Krylov State Research Centre for both hydrodynamic and cavitation characteristics prediction.

Laboratory Experiments on Rotation and Alignment of the Analogs of Interstellar Dust Grains by Radiation

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; Gallagher, D. L.; West, E. A.; Weingartner, J. C.; Witherow, W. K.; Tielens, A. G. G. M.

2004-01-01

The processes and mechanisms involved in the rotation and alignment of interstellar dust grains have been of great interest in astrophysics ever since the surprising discovery of the polarization of starlight more than half a century ago. Numerous theories, detailed mathematical models and numerical studies of grain rotation and alignment with respect to the Galactic magnetic field have been presented in the literature. In particular, the subject of grain rotation and alignment by radiative torques has been shown to be of particular interest in recent years. However, despite many investigations, a satisfactory theoretical understanding of the processes involved in grain rotation and alignment has not been achieved. As there appears to be no experimental data available on this subject, we have carried out some unique experiments to illuminate the processes involved in rotation of dust grains in the interstellar medium. In this paper we present the results of some preliminary laboratory experiments on the rotation of individual micron/submicron size nonspherical dust grains levitated in an electrodynamic balance evacuated to pressures of approximately 10(exp -3) to 10(exp -5) torr. The particles are illuminated by laser light at 5320 Angstroms, and the grain rotation rates are obtained by analyzing the low frequency (approximately 0-100 kHz) signal of the scattered light detected by a photodiode detector. The rotation rates are compared with simple theoretical models to retrieve some basic rotational parameters. The results are examined in the light of the current theories of alignment.

Laboratory Experiments on Rotation of Micron Size Cosmic Dust Grains with Radiation

NASA Technical Reports Server (NTRS)

Abbas, M. M.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; Gallagher, D. L.; West, E.; Weingartner, J.; Witherow, W. K.

2004-01-01

The processes and mechanisms involved in the rotation and alignment of interstellar dust grains have been of great interest in astrophysics ever since the surprising discovery of the polarization of starlight more than half a century ago. Numerous theories, detailed mathematical models and numerical studies of grain rotation and alignment along the Galactic magnetic field have been presented in the literature. In particular, the subject of grain rotation and alignment by radiative torques has been shown to be of particular interest in recent years. However, despite many investigations, a satisfactory theoretical understanding of the processes involved in grain rotation and alignment has not been achieved. As there appears to be no experimental data available on this subject, we have carried out some unique experiments to illuminate the processes involved in rotation of dust grains in the interstellar medium. In this paper we present the results of some preliminary laboratory experiments on the rotation of individual micron/submicron size nonspherical dust grains levitated in an electrodynamic balance evacuated to pressures of approx. 10(exp -3) to 10(exp -5) torr. The particles are illuminated by laser light at 5320 A, and the grain rotation rates are obtained by analyzing the low frequency (approx. 0-100 kHz) signal of the scattered light detected by a photodiode detector. The rotation rates are compared with simple theoretical models to retrieve some basic rotational parameters. The results are examined in the light of the current theories of alignment.

Carbon storage in mangrove and peatland ecosystems: A preliminary account from plots in Indonesia

Treesearch

Daniel Murdiyarso; Daniel Donato; J. Boone Kauffman; Sofyan Kurnianto; Melanie Stidham; Markku Kanninen

2009-01-01

Tropical mangroves and peat swamp forests provide numerous ecosystem services, including nutrient cycling, sediment trapping, protection from cyclones and tsunamis, habitat for numerous organisms (many economically important) and wood for lumber and fuel (Ellison 2008). Among the most important of these functions--but poorly quantified--is ecosystem carbon (C) storage...

SUMS preliminary design and data analysis development. [shuttle upper atmosphere mass spectrometer experiment

NASA Technical Reports Server (NTRS)

Hinson, E. W.

1981-01-01

The preliminary analysis and data analysis system development for the shuttle upper atmosphere mass spectrometer (SUMS) experiment are discussed. The SUMS experiment is designed to provide free stream atmospheric density, pressure, temperature, and mean molecular weight for the high altitude, high Mach number region.

A direct and fast method to monitor lipid oxidation progress in model fatty acid methyl esters by high-performance size-exclusion chromatography.

PubMed

Márquez-Ruiz, G; Holgado, F; García-Martínez, M C; Dobarganes, M C

2007-09-21

A new method based on high-performance size-exclusion chromatography (HPSEC) is proposed to quantitate primary and secondary oxidation compounds in model fatty acid methyl esters (FAMEs). The method consists on simply injecting an aliquot sample in HPSEC, without preliminary isolation procedures neither addition of standard internal. Four groups of compounds can be quantified, namely, unoxidised FAME, oxidised FAME monomers including hydroperoxides, FAME dimers and FAME polymers. Results showed high repeatability and sensitivity, and substantial advantages versus determination of residual substrate by gas-liquid chromatography. Applicability of the method is shown through selected data obtained by numerous oxidation experiments on pure FAME, mainly methyl linoleate, at ambient and moderate temperatures.

[Phosphorus magnetic resonance spectroscopy: Brain pathologies applications].

PubMed

Menuel, C; Guillevin, R; Costalat, R; Perrin, M; Sahli-Amor, M; Martin-Duverneuil, N; Chiras, J

2010-05-01

Until recent years, brain applications of (31)P magnetic resonance spectroscopy were poor. Arising of clinical high field strength magnets (three Tesla) as well as dedicated brain coils (eg: bird cage), using specific and useful sequences providing appropriate spatial localisation and signal to noise ratio brought highlights on multinuclear spectroscopy. Better understanding of brain metabolism emphasizes the role of phosphoenergetic compounds and its potential issues in tumoral, metabolic and degenerative diseases. In the present paper, we report 1 year of experience and preliminary results for 40 patients as well as review of the literature. By successive in vivo determination and quantitation of numerous metabolites it allows, multinuclear spectroscopy may provide additional information to biomathematical models of brain metabolism. Copyright 2009. Published by Elsevier Masson SAS.

Progress on LMJ targets for ignition

NASA Astrophysics Data System (ADS)

Cherfils-Clérouin, C.; Boniface, C.; Bonnefille, M.; Fremerye, P.; Galmiche, D.; Gauthier, P.; Giorla, J.; Lambert, F.; Laffite, S.; Liberatore, S.; Loiseau, P.; Malinie, G.; Masse, L.; Masson-Laborde, P. E.; Monteil, M. C.; Poggi, F.; Seytor, P.; Wagon, F.; Willien, J. L.

2010-08-01

Targets designed to produce ignition on the Laser MegaJoule are presented. The LMJ experimental plans include the attempt of ignition and burn of an ICF capsule with 160 laser beams, delivering up to 1.4MJ and 380TW. New targets needing reduced laser energy with only a small decrease in robustness have then been designed for this purpose. Working specifically on the coupling efficiency parameter, i.e. the ratio of the energy absorbed by the capsule to the laser energy, has led to the design of a rugby-shaped cocktail hohlraum. 1D and 2D robustness evaluations of these different targets shed light on critical points for ignition, that can be traded off by tightening some specifications or by preliminary experimental and numerical tuning experiments.

Spatial and Temporal Variations in Slip Partitioning During Oblique Convergence Experiments

NASA Astrophysics Data System (ADS)

Beyer, J. L.; Cooke, M. L.; Toeneboehn, K.

2017-12-01

Physical experiments of oblique convergence in wet kaolin demonstrate the development of slip partitioning, where two faults accommodate strain via different slip vectors. In these experiments, the second fault forms after the development of the first fault. As one strain component is relieved by one fault, the local stress field then favors the development of a second fault with different slip sense. A suite of physical experiments reveals three styles of slip partitioning development controlled by the convergence angle and presence of a pre-existing fault. In experiments with low convergence angles, strike-slip faults grow prior to reverse faults (Type 1) regardless of whether the fault is precut or not. In experiments with moderate convergence angles, slip partitioning is dominantly controlled by the presence of a pre-existing fault. In all experiments, the primarily reverse fault forms first. Slip partitioning then develops with the initiation of strike-slip along the precut fault (Type 2) or growth of a secondary reverse fault where the first fault is steepest. Subsequently, the slip on the first fault transitions to primarily strike-slip (Type 3). Slip rates and rakes along the slip partitioned faults for both precut and uncut experiments vary temporally, suggesting that faults in these slip-partitioned systems are constantly adapting to the conditions produced by slip along nearby faults in the system. While physical experiments show the evolution of slip partitioning, numerical simulations of the experiments provide information about both the stress and strain fields, which can be used to compute the full work budget, providing insight into the mechanisms that drive slip partitioning. Preliminary simulations of precut experiments show that strain energy density (internal work) can be used to predict fault growth, highlighting where fault growth can reduce off-fault deformation in the physical experiments. In numerical simulations of uncut experiments with a first non-planar oblique slip fault, strain energy density is greatest where the first fault is steepest, as less convergence is accommodated along this portion of the fault. The addition of a second slip-partitioning fault to the system decreases external work indicating that these faults increase the mechanical efficiency of the system.

Analytical and experimental investigation of liquid double drop dynamics: Preliminary design for space shuttle experiments

NASA Technical Reports Server (NTRS)

1981-01-01

The preliminary grant assessed the use of laboratory experiments for simulating low g liquid drop experiments in the space shuttle environment. Investigations were begun of appropriate immiscible liquid systems, design of experimental apparatus and analyses. The current grant continued these topics, completed construction and preliminary testing of the experimental apparatus, and performed experiments on single and compound liquid drops. A continuing assessment of laboratory capabilities, and the interests of project personnel and available collaborators, led to, after consultations with NASA personnel, a research emphasis specializing on compound drops consisting of hollow plastic or elastic spheroids filled with liquids.

Changes in Psychosocial Factors and Physical Activity Frequency among Third- to Eighth-Grade Girls Who Participated in a Developmentally Focused Youth Sport Program: A Preliminary Study

ERIC Educational Resources Information Center

Debate, Rita D.; Gabriel, Kelley Pettee; Zwald, Marissa; Huberty, Jennifer; Zhang, Yan

2009-01-01

Background: Despite the numerous physiological, psychological, and academic benefits of physical activity (PA), declines in PA levels among girls have been observed over the last decade. The purpose of this preliminary study was to assess the short-term changes pertaining to Girls on the Run and Girls on Track developmentally focused youth sport…

Development of PETAL diagnostics: PETAPhys project

NASA Astrophysics Data System (ADS)

Raffestin, D.; Boutoux, G.; Baggio, J.; Batani, D.; Blanchot, N.; Bretheau, D.; Hulin, S.; D'Humieres, E.; Granet, F.; Longhi, Th.; Meyer, Ch.; Moreno, Q.; Nuter, R.; Rault, J.; Tikhonchuk, V.; Universite de Bordeaux/Celia Team; CEA. DAM/Cesta Team

2017-10-01

Beginning of autumn 2017, PETAL, a Petawatt laser beam, will be operated for experiments on the LMJ facility at the CEA/ Cesta research center. The PETAPhys project provides a support to the qualification phase of the PETAL laser operation. Within the PETAPhys project, we are developing two simple and robust diagnostics permitting both to characterize the focal spot of the PETAL beam and to measure the hard X-ray spectrum at each shot. The first diagnostic consists in optical imaging of the PETAL beam focal spot in the spectral range of the second and third harmonic radiation emitted from the target. The second diagnostic is a hard X-ray dosimeter consisting in a stack of imaging plates (IP) and filters, either placed inside a re-entrant tube or inserted close to target. Numerical simulations as well as experiments on small scale facilities have been performed to design these diagnostics. If available, preliminary results from PETAL experiments will be discussed. We acknowledge the financial support from the French National Research Agency (ANR) in the framework of ``the investments for the future'' Programme IdEx Bordeaux-LAPHIA (ANR-10-IDEX-03-02).

Hybrid simulations of weakly collisional plasmas

NASA Astrophysics Data System (ADS)

Xia, Qian; Reville, Brian; Tzoufras, Michail

2016-10-01

Laser produced plasma experiments can be exploited to investigate phenomena of astrophysical relevance. The high densities and velocities that can be generated in the laboratory provide ideal conditions to investigate weakly collisional or collisionless plasma shock physics. In addition, the high temperatures permit magnetic and kinetic Reynolds numbers that are difficult to achieve in other plasma experiments, opening the possibility to study plasma dynamo. Many of these experiments are based on a classic plasma physics problem, namely the interpenetration of two plasma flows. To investigate this phenomenon, we are constructing a novel multi-dimensional hybrid numerical scheme, that solves the ion distribution kinetically via a Vlasov-Fokker-Planck equation, with electrons providing a charge neutralizing fluid. This allows us to follow the evolution on hydrodynamic timescales, while permitting inclusion ofcollisionlesseffects on small scales. It also could be used to study the increasing collisional effects due to the stiff gradient and weakly anisotropic velocity distribution. We present some preliminary validation tests for the code, demonstrating its ability to accurately model key processes that are relevant to laboratory and astrophysical plasmas.

Modeling radium and radon transport through soil and vegetation

USGS Publications Warehouse

Kozak, J.A.; Reeves, H.W.; Lewis, B.A.

2003-01-01

A one-dimensional flow and transport model was developed to describe the movement of two fluid phases, gas and water, within a porous medium and the transport of 226Ra and 222Rn within and between these two phases. Included in this model is the vegetative uptake of water and aqueous 226Ra and 222Rn that can be extracted from the soil via the transpiration stream. The mathematical model is formulated through a set of phase balance equations and a set of species balance equations. Mass exchange, sink terms and the dependence of physical properties upon phase composition couple the two sets of equations. Numerical solution of each set, with iteration between the sets, is carried out leading to a set-iterative compositional model. The Petrov-Galerkin finite element approach is used to allow for upstream weighting if required for a given simulation. Mass lumping improves solution convergence and stability behavior. The resulting numerical model was applied to four problems and was found to produce accurate, mass conservative solutions when compared to published experimental and numerical results and theoretical column experiments. Preliminary results suggest that the model can be used as an investigative tool to determine the feasibility of phytoremediating radium and radon-contaminated soil. ?? 2003 Elsevier Science B.V. All rights reserved.

Time optimal control of a jet engine using a quasi-Hermite interpolation model. M.S. Thesis

NASA Technical Reports Server (NTRS)

Comiskey, J. G.

1979-01-01

This work made preliminary efforts to generate nonlinear numerical models of a two-spooled turbofan jet engine, and subject these models to a known method of generating global, nonlinear, time optimal control laws. The models were derived numerically, directly from empirical data, as a first step in developing an automatic modelling procedure.

Numerical Modelling and Simulation of Dynamic Parameters for Vibration Driven Mobile Robot: Preliminary Study

NASA Astrophysics Data System (ADS)

Baharudin, M. E.; Nor, A. M.; Saad, A. R. M.; Yusof, A. M.

2018-03-01

The motion of vibration-driven robots is based on an internal oscillating mass which can move without legs or wheels. The oscillation of the unbalanced mass by a motor is translated into vibration which in turn produces vertical and horizontal forces. Both vertical and horizontal oscillations are of the same frequency but the phases are shifted. The vertical forces will deflect the bristles which cause the robot to move forward. In this paper, the horizontal motion direction caused by the vertically vibrated bristle is numerically simulated by tuning the frequency of their oscillatory actuation. As a preliminary work, basic equations for a simple off-centered vibration location on the robot platform and simulation model for vibration excitement are introduced. It involves both static and dynamic vibration analysis of robots and analysis of different type of parameters. In addition, the orientation of the bristles and oscillators are also analysed. Results from the numerical integration seem to be in good agreement with those achieved from the literature. The presented numerical integration modeling can be used for designing the bristles and controlling the speed and direction of the robot.

Dynamic load synthesis for shock numerical simulation in space structure design

NASA Astrophysics Data System (ADS)

Monti, Riccardo; Gasbarri, Paolo

2017-08-01

Pyroshock loads are the most stressing environments that a space equipment experiences during its operating life from a mechanical point of view. In general, the mechanical designer considers the pyroshock analysis as a very demanding constraint. Unfortunately, due to the non-linear behaviour of the structure under such loads, only the experimental tests can demonstrate if it is able to withstand these dynamic loads. By taking all the previous considerations into account, some preliminary information about the design correctness could be done by performing ;ad-hoc; numerical simulations, for example via commercial finite element software (i.e. MSC Nastran). Usually these numerical tools face the shock solution in two ways: 1) a direct mode, by using a time dependent enforcement and by evaluating the time-response and space-response as well as the internal forces; 2) a modal basis approach, by considering a frequency dependent load and of course by evaluating internal forces in the frequency domain. This paper has the main aim to develop a numerical tool to synthetize the time dependent enforcement based on deterministic and/or genetic algorithm optimisers. In particular starting from a specified spectrum in terms of SRS (Shock Response Spectrum) a time dependent discrete function, typically an acceleration profile, will be obtained to force the equipment by simulating the shock event. The synthetizing time and the interface with standards numerical codes will be two of the main topics dealt with in the paper. In addition a congruity and consistency methodology will be presented to ensure that the identified time dependent loads fully match the specified spectrum.

Some results on numerical methods for hyperbolic conservation laws

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

Yang Huanan.

1989-01-01

This dissertation contains some results on the numerical solutions of hyperbolic conservation laws. (1) The author introduced an artificial compression method as a correction to the basic ENO schemes. The method successfully prevents contact discontinuities from being smeared. This is achieved by increasing the slopes of the ENO reconstructions in such a way that the essentially non-oscillatory property of the schemes is kept. He analyzes the non-oscillatory property of the new artificial compression method by applying it to the UNO scheme which is a second order accurate ENO scheme, and proves that the resulting scheme is indeed non-oscillatory. Extensive 1-Dmore » numerical results and some preliminary 2-D ones are provided to show the strong performance of the method. (2) He combines the ENO schemes and the centered difference schemes into self-adjusting hybrid schemes which will be called the localized ENO schemes. At or near the jumps, he uses the ENO schemes with the field by field decompositions, otherwise he simply uses the centered difference schemes without the field by field decompositions. The method involves a new interpolation analysis. In the numerical experiments on several standard test problems, the quality of the numerical results of this method is close to that of the pure ENO results. The localized ENO schemes can be equipped with the above artificial compression method. In this way, he dramatically improves the resolutions of the contact discontinuities at very little additional costs. (3) He introduces a space-time mesh refinement method for time dependent problems.« less

Laser flash-photolysis and gas discharge in N2O-containing mixture: kinetic mechanism

NASA Astrophysics Data System (ADS)

Kosarev, Ilya; Popov, Nikolay; Starikovskaia, Svetlana; Starikovskiy, Andrey; mipt Team

2011-10-01

The paper is devoted to further experimental and theoretical analysis of ignition by ArF laser flash-photolysis and nanosecond discharge in N2O-containing mixture has been done. Additional experiments have been made to assure that laser emission is distributed uniformly throughout the cross-section. The series of experiments was proposed and carried out to check validity of O(1D) determination in experiments on plasma assisted ignition initiated by flash-photolysis. In these experiments, ozone density in the given mixture (mixture composition and kinetics has been preliminary analyzed) was measured using UV light absorption in Hartley band. Good coincidence between experimental data and results of calculations have been obtained Temporal behavior of energy input, electric field and electric current has been measured and analyzed. These data are considered as initial conditions for numerical modeling of the discharge in O2:N2O:H2:Ar = 0.3:1:3:5 mixture. Ion-molecular reactions and reactions of active species production in Ar:H2:O2:N2O mixture were analyzed. The set of reactions to describe chemical transformation in the system due to the discharge action has been selected.

Investigation of the effect of a bend in a transfer line that separates a pulse tube cold head and a pressure wave generator

NASA Astrophysics Data System (ADS)

Dev, A. A.; Atrey, M. D.; Vanapalli, S.

2017-02-01

A transfer line between a pulse tube cold head and a pressure wave generator is usually required to isolate the cold head from the vibrations of the compressor. Although it is a common practice to use a thin and narrow straight tube, a bent tube would allow design flexibility and easy mounting of the cold head, such as in a split Stirling type pulse tube cryocooler. In this paper, we report a preliminary investigation on the effect of the bending of the tube on the flow transfer characteristics. A numerical study using commercial computational fluid dynamics model is performed to gain insight into the flow characteristics in the bent tube. Oscillating flow experiments are performed with a straight and a bent tube at a filling pressure of 15 bar and an operating frequency of 40, 50 and 60 Hz. The data and the corresponding numerical simulations point to the hypothesis that the secondary flow in the bent tube causes a decrease in flow at a fixed pressure amplitude.

STARDUST-U experiments on fluid-dynamic conditions affecting dust mobilization during LOVAs

NASA Astrophysics Data System (ADS)

Poggi, L. A.; Malizia, A.; Ciparisse, J. F.; Tieri, F.; Gelfusa, M.; Murari, A.; Del Papa, C.; Giovannangeli, I.; Gaudio, P.

2016-07-01

Since 2006 the Quantum Electronics and Plasma Physics (QEP) Research Group together with ENEA FusTech of Frascati have been working on dust re-suspension inside tokamaks and its potential capability to jeopardize the integrity of future fusion nuclear plants (i.e. ITER or DEMO) and to be a risk for the health of the operators. Actually, this team is working with the improved version of the "STARDUST" facility, i.e. "STARDUST-Upgrade". STARDUST-U facility has four new air inlet ports that allow the experimental replication of Loss of Vacuum Accidents (LOVAs). The experimental campaign to detect the different pressurization rates, local air velocity, temperature, have been carried out from all the ports in different accident conditions and the principal results will be analyzed and compared with the numerical simulations obtained through a CFD (Computational Fluid Dynamic) code. This preliminary thermo fluid-dynamic analysis of the accident is crucial for numerical model development and validation, and for the incoming experimental campaign of dust resuspension inside STARDUST-U due to well-defined accidents presented in this paper.

Numerical predictions and experiments for optimizing hidden corrosion detection in aircraft structures using Lamb modes.

PubMed

Terrien, N; Royer, D; Lepoutre, F; Déom, A

2007-06-01

To increase the sensitivity of Lamb waves to hidden corrosion in aircraft structures, a preliminary step is to understand the phenomena governing this interaction. A hybrid model combining a finite element approach and a modal decomposition method is used to investigate the interaction of Lamb modes with corrosion pits. The finite element mesh is used to describe the region surrounding the corrosion pits while the modal decomposition method permits to determine the waves reflected and transmitted by the damaged area. Simulations make easier the interpretation of some parts of the measured waveform corresponding to superposition of waves diffracted by the corroded area. Numerical results permit to extract significant information from the transmitted waveform and thus to optimize the signal processing for the detection of corrosion at an early stage. Now, we are able to detect corrosion pits down to 80-mum depth distributed randomly on a square centimeter of an aluminum plate. Moreover, thickness variations present on aircraft structures can be discriminated from a slightly corroded area. Finally, using this experimental setup, aircraft structures have been tested.

Work Experiences of People with Mental Illness in Malaysia: A Preliminary Qualitative Study

ERIC Educational Resources Information Center

Boo, Su-Lyn; Loong, Jaymee; Ng, Wai-Sheng

2011-01-01

This is a preliminary qualitative study, using a basic interpretive approach, to investigate the work experiences of people with mental illness in Malaysia. Six females and four males (aged 30-70) from a residential home for the mentally ill participated in semi-structured interviews. Three inter-relating themes emerged, namely the experience of…

Gd uptake experiments for preliminary set of functionalized adsorbents

DOE Data Explorer

Clinton Noack

2015-03-16

These data summarize adsorption experiments conducted with Gd in 0.5 M NaCl. Results represent preliminary, proof-of-concept data utilizing fine-powder silica gel as the adsorbent support. Future testing will focus on larger, application-appropriate beads.

Preliminary Advanced Colloids Experiment

NASA Image and Video Library

2011-09-29

ISS029-E-011867 (29 Sept. 2011) --- NASA astronaut Mike Fossum, Expedition 29 commander, works with the Light Microscopy Module (LMM) control box in the Destiny laboratory of the International Space Station in preparation for another session with the Preliminary Advanced Colloids Experiment (PACE) hardware.

Design and calibration of a rocket-borne electron spectrometer for investigation of particle ionization in the nighttime midlatitude E region

NASA Technical Reports Server (NTRS)

Voss, H. D.; Smith, L. G.

1974-01-01

An explanation was developed for the formation, near midnight at midlatitudes, of a broad electron density layer extending approximately from 120 to 180 km and usually referred to as the intermediate E layer. The responsible mechanism is believed to be the converging vertical ion drifts resulting from winds of the solar semidiurnal tide. Numerical solutions of the continuity equation appropriate to the intermediate layer is described for particular models of ion drift, diffusion coefficents, and ionization production. Analysis of rocket observations of the layer show that the ionization rate is highly correlated with the planetary geomagnetic index, K sub p. Particle flux measurements support the idea that energetic electrons are the principal source of this ionization. A semiconductor spectrometer experiment for investigation of the particle flux, spectrum, and angular properties was designed and successfully flown on a Nike Apache rocket. A detailed description of the theory, design, and calibration of the experiment and some preliminary results presented.

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

Atkin, E.; Shumikhin, V.; Bulatov, V., E-mail: evatkin@mephi.ru, E-mail: shuma.v.v@mail.ru, E-mail: bulat@horizont.e-burg.ru

The NUCLEON experiment was designed to study the chemical composition and energy spectra of galactic cosmic ray nuclei from protons to zinc at energies of ∼ 10{sup 11}–10{sup 15} eV per particle. The research was carried out with the NUCLEON scientific equipment installed on the Russian satellite 'Resource-P' No. 2 as an additional payload. This article presents the results for the measured nuclei spectra related to the first approximately 250 days of the scientific data collection during 2015 and 2016. The all-particle spectrum and the spectra of p, He, C, O, Ne, Mg, Si and Fe are presented. Some interestingmore » ratios of the spectra are also presented and discussed. The experiment is now in its beginning stage and the data still have a preliminary character, but they already give numerous indications of the existence of various non-canonical phenomena in the physics of cosmic rays, which are expressed in the violation of a simple universal power law of the energy spectra. These features of the data are briefly discussed.« less

Characterization of bone microstructure using photoacoustic spectrum analysis

NASA Astrophysics Data System (ADS)

Feng, Ting; Kozloff, Kenneth M.; Xu, Guan; Du, Sidan; Yuan, Jie; Deng, Cheri X.; Wang, Xueding

2015-03-01

Osteoporosis is a progressive bone disease that is characterized by a decrease in bone mass and deterioration in microarchitecture. This study investigates the feasibility of characterizing bone microstructure by analyzing the frequency spectrum of the photoacoustic signals from the bone. Modeling and numerical simulation of photoacoustic signals and their frequency-domain analysis were performed on trabecular bones with different mineral densities. The resulting quasilinear photoacoustic spectra were fit by linear regression, from which spectral parameter slope can be quantified. The modeling demonstrates that, at an optical wavelength of 685 nm, bone specimens with lower mineral densities have higher slope. Preliminary experiment on osteoporosis rat tibia bones with different mineral contents has also been conducted. The finding from the experiment has a good agreement with the modeling, both demonstrating that the frequency-domain analysis of photoacoustic signals can provide objective assessment of bone microstructure and deterioration. Considering that photoacoustic measurement is non-ionizing, non-invasive, and has sufficient penetration in both calcified and noncalcified tissues, this new technology holds unique potential for clinical translation.

The development and preliminary psychometric evaluation of an attachment Implicit Association Task.

PubMed

Venta, Amanda; Jardin, Charles; Kalpakci, Allison; Sharp, Carla

2016-01-01

The importance of measuring attachment insecurity is underscored by a vast literature tying attachment insecurity to numerous psychological disorders. Self-report measures assess explicit attachment beliefs and experiences, while interview measures, like the Adult Attachment Interview, assess implicit internal working models about the self as worthy of care and others as reliable sources of care. The present study is a preliminary psychometric evaluation of a potentially cost-effective method of assessing implicit internal working models of attachment through the development of an Implicit Association Test (IAT). A racially diverse sample of 104 college females was administered Internet-based versions of three IATs (assessing views of the self, mother, and father) as well as self-report measures of attachment and interpersonal problems. Analyses were conducted to evaluate the (a) internal consistency of each task, (b) correlations among the tasks, (c) concurrent validity, and (d) convergent validity. Adequate internal consistency was noted and correlations among the three IATs were significant. No significant associations were observed between the explicit self-report measures of attachment and the IATs. Two primary areas for future research are discussed. First, future research should utilize an implicit attachment measure alongside an IAT. Second, future research should reevaluate the IAT stimuli used.

A robust optimization methodology for preliminary aircraft design

NASA Astrophysics Data System (ADS)

Prigent, S.; Maréchal, P.; Rondepierre, A.; Druot, T.; Belleville, M.

2016-05-01

This article focuses on a robust optimization of an aircraft preliminary design under operational constraints. According to engineers' know-how, the aircraft preliminary design problem can be modelled as an uncertain optimization problem whose objective (the cost or the fuel consumption) is almost affine, and whose constraints are convex. It is shown that this uncertain optimization problem can be approximated in a conservative manner by an uncertain linear optimization program, which enables the use of the techniques of robust linear programming of Ben-Tal, El Ghaoui, and Nemirovski [Robust Optimization, Princeton University Press, 2009]. This methodology is then applied to two real cases of aircraft design and numerical results are presented.

Numerical simulation of a mistral wind event occuring

NASA Astrophysics Data System (ADS)

Guenard, V.; Caccia, J. L.; Tedeschi, G.

2003-04-01

The experimental network of the ESCOMPTE field experiment (june-july 2001) is turned into account to investigate the Mistral wind affecting the Marseille area (South of France). Mistral wind is a northerly flow blowing across the Rhône valley and toward the Mediterranean sea resulting from the dynamical low pressure generated in the wake of the Alps ridge. It brings cold, dry air masses and clear sky conditions over the south-eastern part of France. Up to now, few scientific studies have been carried out on the Mistral wind especially the evolution of its 3-D structure so that its mesoscale numerical simulation is still relevant. Non-hydrostatic RAMS model is performed to better investigate this mesoscale phenomena. Simulations at a 12 km horizontal resolution are compared to boundary layer wind profilers and ground measurements. Preliminary results suit quite well with the Mistral statistical studies carried out by the operational service of Météo-France and observed wind profiles are correctly reproduced by the numerical model RAMS which appears to be an efficient tool for its understanding of Mistral. Owing to the absence of diabatic effect in Mistral events which complicates numerical simulations, the present work is the first step for the validation of RAMS model in that area. Further works will consist on the study of the interaction of Mistral wind with land-sea breeze. Also, RAMS simulations will be combined with aerosol production and ocean circulation models to supply chemists and oceanographers with some answers for their studies.

The Hurricane Rainband and Intensity Change Experiment (RAINEX): Observations and Modeling of Hurricanes Katrina, Ophelia, and Rita (2005)

NASA Astrophysics Data System (ADS)

Houze, R. A.

2006-12-01

The Hurricane Rainband and Intensity Change Experiment (RAINEX) used three P3 aircraft aided by high- resolution numerical modeling and satellite communications to investigate the 2005 Hurricanes Katrina, Ophelia, and Rita. The aim was to increase the understanding of tropical cyclone intensity change by interactions between a tropical cyclone's inner core and rainbands. All three aircraft had dual-Doppler radars, with the ELDORA radar on board the Naval Research Laboratory's P3 aircraft, providing particularly detailed Doppler radar data. Numerical model forecasts helped plan the aircraft missions, and innovative communications and data transfer in real time allowed the flights to be coordinated from a ground-based operations center. The P3 aircraft released approximately 600 dropsondes in locations targeted for optimal coordination with the Doppler radar data, as guided by the operations center. The storms were observed in all stages of development, from Tropical Depression to Category 5 hurricane. The data from RAINEX are readily available through an online Field Catalog and RAINEX Data Archive. The RAINEX dataset is illustrated by a preliminary analysis of Hurricane Rita, which was documented by multi-aircraft flights on five days: 1) while a tropical storm, 2) while rapidly intensifying to a Category 5 hurricane, 3) during an eyewall replacement, 4) when the hurricane became asymmetric upon encountering environmental shear, and 5) just prior to landfall.

Gd uptake experiments for preliminary set of functionalized adsorbents (with content model)

DOE Data Explorer

Clinton Noack

2015-03-16

These data summarize adsorption experiments conducted with Gd in 0.5 M NaCl. Results represent preliminary, proof-of-concept data utilizing fine-powder silica gel as the adsorbent support. Future testing will focus on larger, application-appropriate beads.

Zero-gravity cloud physics laboratory: Experiment program definition and preliminary laboratory concept studies

NASA Technical Reports Server (NTRS)

Eaton, L. R.; Greco, E. V.

1973-01-01

The experiment program definition and preliminary laboratory concept studies on the zero G cloud physics laboratory are reported. This program involves the definition and development of an atmospheric cloud physics laboratory and the selection and delineations of a set of candidate experiments that must utilize the unique environment of zero gravity or near zero gravity.

Recent Progress on the VASIMR

NASA Technical Reports Server (NTRS)

ChangDiaz, Franklin R.; Squire, J. P.; Ilin, A. V.; Jacobson, V. T.; Glover, T. W.; Baity, F. W.; Carter, M. D.; Goulding, R. H.; Breizman, B. N.

1999-01-01

Experimental and theoretical studies on the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) have continued through a NASA led collaborative program involving several research groups. In the experimental area, performance characterization of the VASIMR helicon plasma source has been obtained over a portion of the parameter space, with helium and hydrogen propellant. Density (10(exp 18) - 10(exp 19)/ cubic meter) and temperature (5 eV) were measured at moderate degree of ionization in two separate experimental devices. Helicon design improvement and optimization will be discussed. Experiments with the ion cyclotron resonance heating (ICRH) subsection have begun and preliminary results will be discussed. Theoretical picture and integrated numerical simulation continue to be refined to account for the main physics elements of the VASIMR, including RF absorption and particle acceleration with subsequent detachment in the magnetic nozzle.

A global numerical study of radon-222 and lead-210 in the atmosphere using the AES and York University CDT General Circulation Model (AYCG)

NASA Technical Reports Server (NTRS)

Beagley, Stephen R.; Degrandpre, Jean; Mcconnell, John C.; Laprise, Rene; Mcfarlane, Norman

1994-01-01

The Canadian Climate Center (CCC) GCM has been modified to allow its use for studies in atmospheric chemistry. The initial experiments reported here have been run to test and allow sensitivity studies of the new transport module. The impact of different types of parameterization for the convective mixing have been studied based on the large scale evolution of Rn-222 and Pb-210. Preliminary results have shown that the use of a scheme, which mixes unstable columns over a very short time scale, produces a global distribution of lead that agrees in some aspects with observations. The local impact of different mixing schemes on a short lived tracer like the radon is very important.

Vestibular Function Research (VFR) experiment. Phase B: Design definition study

NASA Technical Reports Server (NTRS)

1978-01-01

The Vestibular Functions Research (VFR) Experiment was established to investigate the neurosensory and related physiological processes believed to be associated with the space flight nausea syndrome and to develop logical means for its prediction, prevention and treatment. The VFR Project consists of ground and spaceflight experimentation using frogs as specimens. The phase B Preliminary Design Study provided for the preliminary design of the experiment hardware, preparation of performance and hardware specification and a Phase C/D development plan, establishment of STS (Space Transportation System) interfaces and mission operations, and the study of a variety of hardware, experiment and mission options. The study consist of three major tasks: (1) mission mode trade-off; (2) conceptual design; and (3) preliminary design.

Approximating a retarded-advanced differential equation that models human phonation

NASA Astrophysics Data System (ADS)

Teodoro, M. Filomena

2017-11-01

In [1, 2, 3] we have got the numerical solution of a linear mixed type functional differential equation (MTFDE) introduced initially in [4], considering the autonomous and non-autonomous case by collocation, least squares and finite element methods considering B-splines basis set. The present work introduces a numerical scheme using least squares method (LSM) and Gaussian basis functions to solve numerically a nonlinear mixed type equation with symmetric delay and advance which models human phonation. The preliminary results are promising. We obtain an accuracy comparable with the previous results.

Novel image processing approach to detect malaria

NASA Astrophysics Data System (ADS)

Mas, David; Ferrer, Belen; Cojoc, Dan; Finaurini, Sara; Mico, Vicente; Garcia, Javier; Zalevsky, Zeev

2015-09-01

In this paper we present a novel image processing algorithm providing good preliminary capabilities for in vitro detection of malaria. The proposed concept is based upon analysis of the temporal variation of each pixel. Changes in dark pixels mean that inter cellular activity happened, indicating the presence of the malaria parasite inside the cell. Preliminary experimental results involving analysis of red blood cells being either healthy or infected with malaria parasites, validated the potential benefit of the proposed numerical approach.

SEASAT economic assessment. Volume 2: The SEASAT system description and performance. [performance prediction and systems analysis for seasat satellites

NASA Technical Reports Server (NTRS)

1975-01-01

Results are presented of preliminary trade-off studies of operational SEASAT systems. The trade-off studies were used as the basis for the estimation of costs and net benefits of the operational SEASAT system. Also presented are the preliminary results of simulation studies that were designed to lead to a measure of the impact of SEASAT data through the use of numerical weather forecast models.

Preliminary design of the HARMONI science software

NASA Astrophysics Data System (ADS)

Piqueras, Laure; Jarno, Aurelien; Pécontal-Rousset, Arlette; Loupias, Magali; Richard, Johan; Schwartz, Noah; Fusco, Thierry; Sauvage, Jean-François; Neichel, Benoît; Correia, Carlos M.

2016-08-01

This paper introduces the science software of HARMONI. The Instrument Numerical Model simulates the instrument from the optical point of view and provides synthetic exposures simulating detector readouts from data-cubes containing astrophysical scenes. The Data Reduction Software converts raw-data frames into a fully calibrated, scientifically usable data cube. We present the functionalities and the preliminary design of this software, describe some of the methods and algorithms used and highlight the challenges that we will have to face.

Numerical-experimental investigation of load paths in DP800 dual phase steel during Nakajima test

NASA Astrophysics Data System (ADS)

Bergs, Thomas; Nick, Matthias; Feuerhack, Andreas; Trauth, Daniel; Klocke, Fritz

2018-05-01

Fuel efficiency requirements demand lightweight construction of vehicle body parts. The usage of advanced high strength steels permits a reduction of sheet thickness while still maintaining the overall strength required for crash safety. However, damage, internal defects (voids, inclusions, micro fractures), microstructural defects (varying grain size distribution, precipitates on grain boundaries, anisotropy) and surface defects (micro fractures, grooves) act as a concentration point for stress and consequently as an initiation point for failure both during deep drawing and in service. Considering damage evolution in the design of car body deep drawing processes allows for a further reduction in material usage and therefore body weight. Preliminary research has shown that a modification of load paths in forming processes can help mitigate the effects of damage on the material. This paper investigates the load paths in Nakajima tests of a DP800 dual phase steel to research damage in deep drawing processes. Investigation is done via a finite element model using experimentally validated material data for a DP800 dual phase steel. Numerical simulation allows for the investigation of load paths with respect to stress states, strain rates and temperature evolution, which cannot be easily observed in physical experiments. Stress triaxiality and the Lode parameter are used to describe the stress states. Their evolution during the Nakajima tests serves as an indicator for damage evolution. The large variety of sheet metal forming specific load paths in Nakajima tests allows a comprehensive evaluation of damage for deep drawing. The results of the numerical simulation conducted in this project and further physical experiments will later be used to calibrate a damage model for simulation of deep drawing processes.

Preliminary design polymeric materials experiment. [for space shuttles and Spacelab missions

NASA Technical Reports Server (NTRS)

Mattingly, S. G.; Rude, E. T.; Marshner, R. L.

1975-01-01

A typical Advanced Technology Laboratory mission flight plan was developed and used as a guideline for the identification of a number of experiment considerations. The experiment logistics beginning with sample preparation and ending with sample analysis are then overlaid on the mission in order to have a complete picture of the design requirements. The results of this preliminary design study fall into two categories. First specific preliminary designs of experiment hardware which is adaptable to a variety of mission requirements. Second, identification of those mission considerations which affect hardware design and will require further definition prior to final design. Finally, a program plan is presented which will provide the necessary experiment hardware in a realistic time period to match the planned shuttle flights. A bibliography of all material reviewed and consulted but not specifically referenced is provided.

Aerodynamic Design and Numerical Analysis of Supersonic Turbine for Turbo Pump

NASA Astrophysics Data System (ADS)

Fu, Chao; Zou, Zhengping; Kong, Qingguo; Cheng, Honggui; Zhang, Weihao

2016-09-01

Supersonic turbine is widely used in the turbo pump of modern rocket. A preliminary design method for supersonic turbine has been developed considering the coupling effects of turbine and nozzle. Numerical simulation has been proceeded to validate the feasibility of the design method. As the strong shockwave reflected on the mixing plane, additional numerical simulated error would be produced by the mixing plane model in the steady CFD. So unsteady CFD is employed to investigate the aerodynamic performance of the turbine and flow field in passage. Results showed that the preliminary design method developed in this paper is suitable for designing supersonic turbine. This periodical variation of complex shockwave system influences the development of secondary flow, wake and shock-boundary layer interaction, which obviously affect the secondary loss in vane passage. The periodical variation also influences the strength of reflecting shockwave, which affects the profile loss in vane passage. Besides, high circumferential velocity at vane outlet and short blade lead to high radial pressure gradient, which makes the low kinetic energy fluid moves towards hub region and produces additional loss.

Multidisciplinary optimization of an HSCT wing using a response surface methodology

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

Giunta, A.A.; Grossman, B.; Mason, W.H.

1994-12-31

Aerospace vehicle design is traditionally divided into three phases: conceptual, preliminary, and detailed. Each of these design phases entails a particular level of accuracy and computational expense. While there are several computer programs which perform inexpensive conceptual-level aircraft multidisciplinary design optimization (MDO), aircraft MDO remains prohibitively expensive using preliminary- and detailed-level analysis tools. This occurs due to the expense of computational analyses and because gradient-based optimization requires the analysis of hundreds or thousands of aircraft configurations to estimate design sensitivity information. A further hindrance to aircraft MDO is the problem of numerical noise which occurs frequently in engineering computations. Computermore » models produce numerical noise as a result of the incomplete convergence of iterative processes, round-off errors, and modeling errors. Such numerical noise is typically manifested as a high frequency, low amplitude variation in the results obtained from the computer models. Optimization attempted using noisy computer models may result in the erroneous calculation of design sensitivities and may slow or prevent convergence to an optimal design.« less

Evaluating aerosol impacts on Numerical Weather Prediction in two extreme dust and biomass-burning events

NASA Astrophysics Data System (ADS)

Remy, Samuel; Benedetti, Angela; Jones, Luke; Razinger, Miha; Haiden, Thomas

2014-05-01

The WMO-sponsored Working Group on Numerical Experimentation (WGNE) set up a project aimed at understanding the importance of aerosols for numerical weather prediction (NWP). Three cases are being investigated by several NWP centres with aerosol capabilities: a severe dust case that affected Southern Europe in April 2012, a biomass burning case in South America in September 2012, and an extreme pollution event in Beijing (China) which took place in January 2013. At ECMWF these cases are being studied using the MACC-II system with radiatively interactive aerosols. Some preliminary results related to the dust and the fire event will be presented here. A preliminary verification of the impact of the aerosol-radiation direct interaction on surface meteorological parameters such as 2m Temperature and surface winds over the region of interest will be presented. Aerosol optical depth (AOD) verification using AERONET data will also be discussed. For the biomass burning case, the impact of using injection heights estimated by a Plume Rise Model (PRM) for the biomass burning emissions will be presented.

A numerical simulation of finite-length Taylor-Couette flow

NASA Technical Reports Server (NTRS)

Streett, C. L.; Hussaini, M. Y.

1988-01-01

Results from numerical simulations of finite-length Taylor-Couette flow are presented. Included are time-accurate and steady-state studies of the change in the nature of the symmetric two-cell/asymmetric one-cell bifurcation with varying aspect ratio and of the Reynolds number/aspect ratio locus of the two-cell/four-cell bifurcation. Preliminary results from wavy-vortex simulations at low aspect ratios are also presented.

Numerical Computation of a Continuous-thrust State Transition Matrix Incorporating Accurate Hardware and Ephemeris Models

NASA Technical Reports Server (NTRS)

Ellison, Donald; Conway, Bruce; Englander, Jacob

2015-01-01

A significant body of work exists showing that providing a nonlinear programming (NLP) solver with expressions for the problem constraint gradient substantially increases the speed of program execution and can also improve the robustness of convergence, especially for local optimizers. Calculation of these derivatives is often accomplished through the computation of spacecraft's state transition matrix (STM). If the two-body gravitational model is employed as is often done in the context of preliminary design, closed form expressions for these derivatives may be provided. If a high fidelity dynamics model, that might include perturbing forces such as the gravitational effect from multiple third bodies and solar radiation pressure is used then these STM's must be computed numerically. We present a method for the power hardward model and a full ephemeris model. An adaptive-step embedded eight order Dormand-Prince numerical integrator is discussed and a method for the computation of the time of flight derivatives in this framework is presented. The use of these numerically calculated derivatieves offer a substantial improvement over finite differencing in the context of a global optimizer. Specifically the inclusion of these STM's into the low thrust missiondesign tool chain in use at NASA Goddard Spaceflight Center allows for an increased preliminary mission design cadence.

Source Term Model for Vortex Generator Vanes in a Navier-Stokes Computer Code

NASA Technical Reports Server (NTRS)

Waithe, Kenrick A.

2004-01-01

A source term model for an array of vortex generators was implemented into a non-proprietary Navier-Stokes computer code, OVERFLOW. The source term models the side force created by a vortex generator vane. The model is obtained by introducing a side force to the momentum and energy equations that can adjust its strength automatically based on the local flow. The model was tested and calibrated by comparing data from numerical simulations and experiments of a single low profile vortex generator vane on a flat plate. In addition, the model was compared to experimental data of an S-duct with 22 co-rotating, low profile vortex generators. The source term model allowed a grid reduction of about seventy percent when compared with the numerical simulations performed on a fully gridded vortex generator on a flat plate without adversely affecting the development and capture of the vortex created. The source term model was able to predict the shape and size of the stream-wise vorticity and velocity contours very well when compared with both numerical simulations and experimental data. The peak vorticity and its location were also predicted very well when compared to numerical simulations and experimental data. The circulation predicted by the source term model matches the prediction of the numerical simulation. The source term model predicted the engine fan face distortion and total pressure recovery of the S-duct with 22 co-rotating vortex generators very well. The source term model allows a researcher to quickly investigate different locations of individual or a row of vortex generators. The researcher is able to conduct a preliminary investigation with minimal grid generation and computational time.

Analysis of the thermo-mechanical deformations in a hot forging tool by numerical simulation

NASA Astrophysics Data System (ADS)

L-Cancelos, R.; Varas, F.; Martín, E.; Viéitez, I.

2016-03-01

Although programs have been developed for the design of tools for hot forging, its design is still largely based on the experience of the tool maker. This obliges to build some test matrices and correct their errors to minimize distortions in the forged piece. This phase prior to mass production consumes time and material resources, which makes the final product more expensive. The forging tools are usually constituted by various parts made of different grades of steel, which in turn have different mechanical properties and therefore suffer different degrees of strain. Furthermore, the tools used in the hot forging are exposed to a thermal field that also induces strain or stress based on the degree of confinement of the piece. Therefore, the mechanical behaviour of the assembly is determined by the contact between the different pieces. The numerical simulation allows to analyse different configurations and anticipate possible defects before tool making, thus, reducing the costs of this preliminary phase. In order to improve the dimensional quality of the manufactured parts, the work presented here focuses on the application of a numerical model to a hot forging manufacturing process in order to predict the areas of the forging die subjected to large deformations. The thermo-mechanical model developed and implemented with free software (Code-Aster) includes the strains of thermal origin, strains during forge impact and contact effects. The numerical results are validated with experimental measurements in a tooling set that produces forged crankshafts for the automotive industry. The numerical results show good agreement with the experimental tests. Thereby, a very useful tool for the design of tooling sets for hot forging is achieved.

An Investigation of the Flow Physics of Acoustic Liners by Direct Numerical Simulation

NASA Technical Reports Server (NTRS)

Watson, Willie R. (Technical Monitor); Tam, Christopher

2004-01-01

This report concentrates on reporting the effort and status of work done on three dimensional (3-D) simulation of a multi-hole resonator in an impedance tube. This work is coordinated with a parallel experimental effort to be carried out at the NASA Langley Research Center. The outline of this report is as follows : 1. Preliminary consideration. 2. Computation model. 3. Mesh design and parallel computing. 4. Visualization. 5. Status of computer code development. 1. Preliminary Consideration.

Thick ceramic coating development for industrial gas turbines - A program plan

NASA Technical Reports Server (NTRS)

Vogan, J. W.; Stetson, A. R.

1979-01-01

A program plan on a NASA-Lewis funded program is presented, in which effectiveness of thick ceramic coatings in preventing hot corrosion and in providing thermal insulation to gas turbine engine components are to be investigated. Preliminary analysis of the benefit of the thermal insulating effect of this coating on decreasing cooling air and simplifying component design appears very encouraging. The program is in the preliminary stages of obtaining starting materials and establishing procedures. Numerous graphs, tables and photographs are included.

The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States

USGS Publications Warehouse

Horton, John D.; San Juan, Carma A.; Stoeser, Douglas B.

2017-06-30

The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States (https://doi. org/10.5066/F7WH2N65) represents a seamless, spatial database of 48 State geologic maps that range from 1:50,000 to 1:1,000,000 scale. A national digital geologic map database is essential in interpreting other datasets that support numerous types of national-scale studies and assessments, such as those that provide geochemistry, remote sensing, or geophysical data. The SGMC is a compilation of the individual U.S. Geological Survey releases of the Preliminary Integrated Geologic Map Databases for the United States. The SGMC geodatabase also contains updated data for seven States and seven entirely new State geologic maps that have been added since the preliminary databases were published. Numerous errors have been corrected and enhancements added to the preliminary datasets using thorough quality assurance/quality control procedures. The SGMC is not a truly integrated geologic map database because geologic units have not been reconciled across State boundaries. However, the geologic data contained in each State geologic map have been standardized to allow spatial analyses of lithology, age, and stratigraphy at a national scale.

Feasibility and systems definition study for microwave multi-application payload (MMAP)

NASA Technical Reports Server (NTRS)

Horton, J. B.; Allen, C. C.; Massaro, M. J.; Zemany, J. L.; Murrell, J. W.; Stanhouse, R. W.; Condon, G. P.; Stone, R. F.

1977-01-01

There were three Shuttle/Spacelab experiments: adaptive multibeam phased array antenna (AMPA) experiment, electromagnetic environment experiment (EEE), and millimeter wave communications experiment (MWCE). Work on the AMPA experiment was completed. Results included are definition of operating modes, sequence of operation, radii of operation about several ground stations, signal format, foot prints of typical orbits and preliminary definition of ground and user terminals. Definition of the MOD I EEE included conceptual hardware designs, spacelab interfaces, preliminary data handling methods, experiment tests and verification, and EMC studies. The MWCE was defined conceptually for a steerable high gain antenna.

Survey of CELSS Concepts and Preliminary Research in Japan

NASA Technical Reports Server (NTRS)

Ohya, H.; Oshima, T.; Nitta, K.

1985-01-01

Agricultural and other experiments relating to the development of a controlled ecological life support system (CELSS) were proposed. The engineering feasibility of each proposal was investigated by a CELSS experiment concept met study group. The CELSS experiment concept to clarify the goals of CELSS and to determine three phases to achieve the goals. The resulting phases, or missions, and preliminary proposals and studies needed to develop a CELSS are described.

Integrated support structure for GASCAN 2

NASA Technical Reports Server (NTRS)

1990-01-01

The focus of the Worcester Polytechnic Institute (WPI) Advanced Space Design Program was the preliminary design of the Integrated Support Structure for GASCAN II, a Get Away Special canister donated by the MITRE Corporation. Two teams of three students each worked on the support structure. There was a structural design team and a thermal design team. The structure will carry three experiments also undergoing preliminary design this year, the mu-gravity Ignition Experiment, the Rotational Flow in Low Gravity Experiment, and the Ionospheric Properties and Propagation Experiment. The structural design team was responsible for the layout of the GASCAN and the preliminary design of the structure itself. They produced the physical interface specifications defining the baseline weights and volumes for the equipment and produced layout drawings of the system. The team produced static and modal finite element analysis of the structure using ANSYS. The thermal design team was responsible for the power and timing requirements of the payload and for the identification and preliminary analysis of potential thermal problems. The team produced the power, timing, and energy interface specifications and assisted in the development of the specification of the battery pack. The thermal parameters of each experiment were cataloged and the experiments were subjected to worst case heat transfer scenarios.

A diffraction correction for storage and loss moduli imaging using radiation force based elastography.

PubMed

Budelli, Eliana; Brum, Javier; Bernal, Miguel; Deffieux, Thomas; Tanter, Mickaël; Lema, Patricia; Negreira, Carlos; Gennisson, Jean-Luc

2017-01-07

Noninvasive evaluation of the rheological behavior of soft tissues may provide an important diagnosis tool. Nowadays, available commercial ultrasound systems only provide shear elasticity estimation by shear wave speed assessment under the hypothesis of a purely elastic model. However, to fully characterize the rheological behavior of tissues, given by its storage (G') and loss (G″) moduli, it is necessary to estimate both: shear wave speed and shear wave attenuation. Most elastography techniques use the acoustic radiation force to generate shear waves. For this type of source the shear waves are not plane and a diffraction correction is needed to properly estimate the shear wave attenuation. The use of a cylindrical wave approximation to evaluate diffraction has been proposed by other authors before. Here the validity of such approximation is numerically and experimentally revisited. Then, it is used to generate images of G' and G″ in heterogeneous viscoelastic mediums. A simulation algorithm based on the anisotropic and viscoelastic Green's function was used to establish the validity of the cylindrical approximation. Moreover, two experiments were carried out: a transient elastography experiment where plane shear waves were generated using a vibrating plate and a SSI experiment that uses the acoustic radiation force to generate shear waves. For both experiments the shear wave propagation was followed with an ultrafast ultrasound scanner. Then, the shear wave velocity and shear wave attenuation were recovered from the phase and amplitude decay versus distance respectively. In the SSI experiment the cylindrical approximation was applied to correct attenuation due to diffraction effects. The numerical and experimental results validate the use of a cylindrical correction to assess shear wave attenuation. Finally, by applying the cylindrical correction G' and G″ images were generated in heterogeneous phantoms and a preliminary in vivo feasibility study was carried out in the human liver.

A diffraction correction for storage and loss moduli imaging using radiation force based elastography

NASA Astrophysics Data System (ADS)

Budelli, Eliana; Brum, Javier; Bernal, Miguel; Deffieux, Thomas; Tanter, Mickaël; Lema, Patricia; Negreira, Carlos; Gennisson, Jean-Luc

2017-01-01

Noninvasive evaluation of the rheological behavior of soft tissues may provide an important diagnosis tool. Nowadays, available commercial ultrasound systems only provide shear elasticity estimation by shear wave speed assessment under the hypothesis of a purely elastic model. However, to fully characterize the rheological behavior of tissues, given by its storage (G‧) and loss (G″) moduli, it is necessary to estimate both: shear wave speed and shear wave attenuation. Most elastography techniques use the acoustic radiation force to generate shear waves. For this type of source the shear waves are not plane and a diffraction correction is needed to properly estimate the shear wave attenuation. The use of a cylindrical wave approximation to evaluate diffraction has been proposed by other authors before. Here the validity of such approximation is numerically and experimentally revisited. Then, it is used to generate images of G‧ and G″ in heterogeneous viscoelastic mediums. A simulation algorithm based on the anisotropic and viscoelastic Green’s function was used to establish the validity of the cylindrical approximation. Moreover, two experiments were carried out: a transient elastography experiment where plane shear waves were generated using a vibrating plate and a SSI experiment that uses the acoustic radiation force to generate shear waves. For both experiments the shear wave propagation was followed with an ultrafast ultrasound scanner. Then, the shear wave velocity and shear wave attenuation were recovered from the phase and amplitude decay versus distance respectively. In the SSI experiment the cylindrical approximation was applied to correct attenuation due to diffraction effects. The numerical and experimental results validate the use of a cylindrical correction to assess shear wave attenuation. Finally, by applying the cylindrical correction G‧ and G″ images were generated in heterogeneous phantoms and a preliminary in vivo feasibility study was carried out in the human liver.

Preliminary Numerical Simulation of IR Structure Development in a Hypothetical Uranium Release.

DTIC Science & Technology

1981-11-16

art Identify by block nAsb.’) IR Structure Power spectrum Uranium release Parallax effects Numerical simulation PHARO code Isophots LWIR 20. _PSTRACT...release at 200 km altitude. Of interest is the LWIR emission from uranium oxide ions, induced by sunlight and earthshine. Assuming a one-level fluid...defense systems of long wave infrared ( LWIR ) emissions from metallic oxides in the debris from a high altitude nuclear explosion (HANE) is an

Electromagnetic Field Effects in Semiconductor Crystal Growth

NASA Technical Reports Server (NTRS)

Dulikravich, George S.

1996-01-01

This proposed two-year research project was to involve development of an analytical model, a numerical algorithm for its integration, and a software for the analysis of a solidification process under the influence of electric and magnetic fields in microgravity. Due to the complexity of the analytical model that was developed and its boundary conditions, only a preliminary version of the numerical algorithm was developed while the development of the software package was not completed.

THE MORPHOLOGICAL BASIS FOR OLFACTORY PERCEPTION OF STEROIDS DUING AGONISTIC BEHAVIOR IN LOBSTER: PRELIMINARY EXPERIMENTS

EPA Science Inventory

The morphological basis for olfactory perception of steroids during agonistic behavior in lobsters: preliminary experiments. Borsay Horowitz, DJ1, Kass-Simon, G2, Coglianese, D2, Martin, L2, Boseman, M2, Cromarty, S3, Randall, K3, Fini, A.3 1US EPA, NHEERL, ORD, Atlantic Ecology...

Global Experience: The Development and Preliminary Evaluation of a Programme Designed to Enhance Students' Global Engagement

ERIC Educational Resources Information Center

Feast, Vicki; Collyer-Braham, Sarah; Bretag, Tracey

2011-01-01

This paper reports on the development and preliminary evaluation of "Global Experience", an innovative programme at the University of South Australia designed to broaden students' intercultural engagement through a range of international experiential activities. The paper provides the rationale for the establishment of the programme…

A New Way to Generate Collimated Plasma Jets?

NASA Astrophysics Data System (ADS)

Young, Rachel; Kuranz, C. C.; Sweeney, R. M.; Drake, R. P.

2012-05-01

We may have a new way to generate collimated, high-Mach-number plasma jets for laboratory astrophysics experiments. Analytic calculations show that irradiating the rear side of a cone-shaped foil can produce a collimated plasma jet with a Mach number of more than 2. Preliminary numeric simulations confirm this. We intend to test this method with a day of experiments at OMEGA (Laboratory for Laser Energetics, Rochester, New York) in April 2012; results may be available in time for this meeting. If successful, this will be the first step in an experimental campaign to investigate the affects of magnetic fields on mixing plasma jets. We hope to create a swirling disk of magnetized plasma_and possibly witness the turbulent dynamo_by firing roughly half a dozen such jets towards each other. However, for such an experiment to succeed, the disk must rotate more quickly than it expands, requiring the contributing jets to have M > 2. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, grant number DE-FG52-09NA29548, and by the National Laser User Facility Program, grant number DE-NA0000850.

Classical problems in computational aero-acoustics

NASA Technical Reports Server (NTRS)

Hardin, Jay C.

1996-01-01

In relation to the expected problems in the development of computational aeroacoustics (CAA), the preliminary applications were to classical problems where the known analytical solutions could be used to validate the numerical results. Such comparisons were used to overcome the numerical problems inherent in these calculations. Comparisons were made between the various numerical approaches to the problems such as direct simulations, acoustic analogies and acoustic/viscous splitting techniques. The aim was to demonstrate the applicability of CAA as a tool in the same class as computational fluid dynamics. The scattering problems that occur are considered and simple sources are discussed.

Utilization of a Vircator to drive a High Power Relativistic Klystron Amplifier

NASA Astrophysics Data System (ADS)

Gardelle, J.; Bardy, J.; Cassany, B.; Desanlis, T.; Eyl, P.; Galtié, A.; Modin, P.; Voisin, L.; Balleyguier, P.; Gouard, P.; Donohue, J.

2002-11-01

At CESTA, we have been producing electron beams for some fifteen years by using induction accelerators and pulse diodes. First we had performed Frre-Electron Lasers experiments and we are currently studying the production of High-Power microwaves in the S-band. Among the possible sources we have chosen to perform Relativistic Klystron (RK) experiments with a pulse diode capable of generating a 700kV, 15 kA, 100 ns annular electron beam. In an amplifier configuration, we are testing the idea of using a Vircator as the driver for the first cavity of the klystron. This Vircator uses a simple electrical generator (Marx capacitor bank) which operates in the S-band in the GW class. By reducing the power level to about 100 MW, a 200 ns reliable and reproducible input driver pulse is obtained. First, we present the results of a preliminary experiment for which a coaxial cavity has been built in order to be fed by the Vircator emission at 2.45 GHz. Secondly, we give the experimental results in an oscillator configuration which corresponds to the fisrt step of our RK studies. Comparisons with the results of numerical simulations performed with MAGIC and MAFIA will be given for both experiments.

Preliminary design and hazards report. Boiling Reactor Experiment V (BORAX V)

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

Rice, R. E.

1960-02-01

The preliminary objectives of the proposed BORAX V program are to test nuclear superheating concepts and to advance the technology of boiling-water-reactor design by performing experiments which will improve the understanding of factors limiting the stability of boiling reactors at high power densities. The reactor vessel is a cylinder with ellipsoidal heads, made of carbon steel clad internally with stainless steel. Each of the three cores is 24 in. high and has an effective diameter of 39 in. This is a preliminary report. (W.D.M.)

Sensitivity of the model error parameter specification in weak-constraint four-dimensional variational data assimilation

NASA Astrophysics Data System (ADS)

Shaw, Jeremy A.; Daescu, Dacian N.

2017-08-01

This article presents the mathematical framework to evaluate the sensitivity of a forecast error aspect to the input parameters of a weak-constraint four-dimensional variational data assimilation system (w4D-Var DAS), extending the established theory from strong-constraint 4D-Var. Emphasis is placed on the derivation of the equations for evaluating the forecast sensitivity to parameters in the DAS representation of the model error statistics, including bias, standard deviation, and correlation structure. A novel adjoint-based procedure for adaptive tuning of the specified model error covariance matrix is introduced. Results from numerical convergence tests establish the validity of the model error sensitivity equations. Preliminary experiments providing a proof-of-concept are performed using the Lorenz multi-scale model to illustrate the theoretical concepts and potential benefits for practical applications.

Encrypted optical storage with wavelength-key and random phase codes.

PubMed

Matoba, O; Javidi, B

1999-11-10

An encrypted optical memory system that uses a wavelength code as well as input and Fourier-plane random phase codes is proposed. Original data are illuminated by a coherent light source with a specified wavelength and are then encrypted with two random phase codes before being stored holographically in a photorefractive material. Successful decryption requires the use of a readout beam with the same wavelength as that used in the recording, in addition to the correct phase key in the Fourier plane. The wavelength selectivity of the proposed system is evaluated numerically. We show that the number of available wavelength keys depends on the correlation length of the phase key in the Fourier plane. Preliminary experiments of encryption and decryption of optical memory in a LiNbO(3):Fe photorefractive crystal are demonstrated.

Coherent control with optical pulses for deterministic spin-photon entanglement

NASA Astrophysics Data System (ADS)

Truex, Katherine; Webster, L. A.; Duan, L.-M.; Sham, L. J.; Steel, D. G.

2013-11-01

We present a procedure for the optical coherent control of quantum bits within a quantum dot spin-exciton system, as a preliminary step to implementing a proposal by Yao, Liu, and Sham [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.95.030504 95, 030504 (2005)] for deterministic spin-photon entanglement. The experiment proposed here utilizes a series of picosecond optical pulses from a single laser to coherently control a single self-assembled quantum dot in a magnetic field, creating the precursor state in 25 ps with a predicted fidelity of 0.991. If allowed to decay in an appropriate cavity, the ideal precursor superposition state would create maximum spin-photon entanglement. Numerical simulations using values typical of InAs quantum dots give a predicted entropy of entanglement of 0.929, largely limited by radiative decay and electron spin flips.

Computational analysis of water entry of a circular section at constant velocity based on Reynold's averaged Navier-Stokes method

NASA Astrophysics Data System (ADS)

Uddin, M. Maruf; Fuad, Muzaddid-E.-Zaman; Rahaman, Md. Mashiur; Islam, M. Rabiul

2017-12-01

With the rapid decrease in the cost of computational infrastructure with more efficient algorithm for solving non-linear problems, Reynold's averaged Navier-Stokes (RaNS) based Computational Fluid Dynamics (CFD) has been used widely now-a-days. As a preliminary evaluation tool, CFD is used to calculate the hydrodynamic loads on offshore installations, ships, and other structures in the ocean at initial design stages. Traditionally, wedges have been studied more than circular cylinders because cylinder section has zero deadrise angle at the instant of water impact, which increases with increase of submergence. In Present study, RaNS based commercial code ANSYS Fluent is used to simulate the water entry of a circular section at constant velocity. It is seen that present computational results were compared with experiment and other numerical method.

DNS of Flow in a Low-Pressure Turbine Cascade Using a Discontinuous-Galerkin Spectral-Element Method

NASA Technical Reports Server (NTRS)

Garai, Anirban; Diosady, Laslo Tibor; Murman, Scott; Madavan, Nateri

2015-01-01

A new computational capability under development for accurate and efficient high-fidelity direct numerical simulation (DNS) and large eddy simulation (LES) of turbomachinery is described. This capability is based on an entropy-stable Discontinuous-Galerkin spectral-element approach that extends to arbitrarily high orders of spatial and temporal accuracy and is implemented in a computationally efficient manner on a modern high performance computer architecture. A validation study using this method to perform DNS of flow in a low-pressure turbine airfoil cascade are presented. Preliminary results indicate that the method captures the main features of the flow. Discrepancies between the predicted results and the experiments are likely due to the effects of freestream turbulence not being included in the simulation and will be addressed in the final paper.

Dynamic behavior of geometrically complex hybrid composite samples in a Split-Hopkinson Pressure Bar system

NASA Astrophysics Data System (ADS)

Pouya, M.; Balasubramaniam, S.; Sharafiev, S.; F-X Wagner, M.

2018-06-01

The interfaces between layered materials play an important role for the overall mechanical behavior of hybrid composites, particularly during dynamic loading. Moreover, in complex-shaped composites, interfacial failure is strongly affected by the geometry and size of these contact interfaces. As preliminary work for the design of a novel sample geometry that allows to analyze wave reflection phenomena at the interfaces of such materials, a series of experiments using a Split-Hopkinson Pressure Bar technique was performed on five different sample geometries made of a monomaterial steel. A complementary explicit finite element model of the Split-Hopkinson Pressure Bar system was developed and the same sample geometries were studied numerically. The simulated input, reflected and transmitted elastic wave pulses were analyzed for the different sample geometries and were found to agree well with the experimental results. Additional simulations using different composite layers of steel and aluminum (with the same sample geometries) were performed to investigate the effect of material variation on the propagated wave pulses. The numerical results show that the reflected and transmitted wave pulses systematically depend on the sample geometry, and that elastic wave pulse propagation is affected by the properties of individual material layers.

3D-PTV around Operational Wind Turbines

NASA Astrophysics Data System (ADS)

Brownstein, Ian; Dabiri, John

2016-11-01

Laboratory studies and numerical simulations of wind turbines are typically constrained in how they can inform operational turbine behavior. Laboratory experiments are usually unable to match both pertinent parameters of full-scale wind turbines, the Reynolds number (Re) and tip speed ratio, using scaled-down models. Additionally, numerical simulations of the flow around wind turbines are constrained by the large domain size and high Re that need to be simulated. When these simulations are preformed, turbine geometry is typically simplified resulting in flow structures near the rotor not being well resolved. In order to bypass these limitations, a quantitative flow visualization method was developed to take in situ measurements of the flow around wind turbines at the Field Laboratory for Optimized Wind Energy (FLOWE) in Lancaster, CA. The apparatus constructed was able to seed an approximately 9m x 9m x 5m volume in the wake of the turbine using artificial snow. Quantitative measurements were obtained by tracking the evolution of the artificial snow using a four camera setup. The methodology for calibrating and collecting data, as well as preliminary results detailing the flow around a 2kW vertical-axis wind turbine (VAWT), will be presented.

Numerical optimization of the ramp-down phase with the RAPTOR code

NASA Astrophysics Data System (ADS)

Teplukhina, Anna; Sauter, Olivier; Felici, Federico; The Tcv Team; The ASDEX-Upgrade Team; The Eurofusion Mst1 Team

2017-10-01

The ramp-down optimization goal in this work is defined as the fastest possible decrease of a plasma current while avoiding any disruptions caused by reaching physical or technical limits. Numerical simulations and preliminary experiments on TCV and AUG have shown that a fast decrease of plasma elongation and an adequate timing of the H-L transition during current ramp-down can help to avoid reaching high values of the plasma internal inductance. The RAPTOR code (F. Felici et al., 2012 PPCF 54; F. Felici, 2011 EPFL PhD thesis), developed for real-time plasma control, has been used for an optimization problem solving. Recently the transport model has been extended to include the ion temperature and electron density transport equations in addition to the electron temperature and current density transport equations, increasing the physical applications of the code. The gradient-based models for the transport coefficients (O. Sauter et al., 2014 PPCF 21; D. Kim et al., 2016 PPCF 58) have been implemented to RAPTOR and tested during this work. Simulations of the AUG and TCV entire plasma discharges will be presented. See the author list of S. Coda et al., Nucl. Fusion 57 2017 102011.

Comparative efficiency analysis of fiber-array and conventional beam director systems in volume turbulence.

PubMed

Vorontsov, Mikhail; Filimonov, Grigory; Ovchinnikov, Vladimir; Polnau, Ernst; Lachinova, Svetlana; Weyrauch, Thomas; Mangano, Joseph

2016-05-20

The performance of two prominent laser beam projection system types is analyzed through wave-optics numerical simulations for various atmospheric turbulence conditions, propagation distances, and adaptive optics (AO) mitigation techniques. Comparisons are made between different configurations of both a conventional beam director (BD) using a monolithic-optics-based Cassegrain telescope and a fiber-array BD that uses an array of densely packed fiber collimators. The BD systems considered have equal input power and aperture diameters. The projected laser beam power inside the Airy size disk at the target plane is used as the performance metric. For the fiber-array system, both incoherent and coherent beam combining regimes are considered. We also present preliminary results of side-by-side atmospheric beam projection experiments over a 7-km propagation path using both the AO-enhanced beam projection system with a Cassegrain telescope and the coherent fiber-array BD composed of 21 densely packed fiber collimators. Both wave-optics numerical simulation and experimental results demonstrate that, for similar system architectures and turbulence conditions, coherent fiber-array systems are more efficient in mitigation of atmospheric turbulence effects and generation of a hit spot of the smallest possible size on a remotely located target.

A Numerical Approach to the Accretion of Micro-Continental Blocks and Subsequent Subduction Initiation

NASA Astrophysics Data System (ADS)

Gün, E.; Gogus, O.; Pysklywec, R.; Topuz, G.; Bodur, O. F.

2017-12-01

The Tethyan belt in the eastern Mediterranean region is characterized by the accretion of several micro-continental blocks (e.g. Anatolide-Tauride, Sakarya and Istanbul terranes). The accretion of a micro-continental block to the active continental margin and subsequent initiation of a new subduction are of crucial importance in understanding the geodynamic evolution of the region. Numerical geodynamic experiments are designed to investigate how these micro-continental blocks in the ocean-continent subduction system develops the aforementioned subduction, back-arc extension, surface uplift and the ophiolite emplacement in the eastern Mediterranean since Late Cretaceous. In a series set of experiments, we test various sizes of micro-continental blocks (ranging from 50 to 300 km), different rheological properties (e.g. dry-wet olivine mantle) and imposed plate convergence velocities (0 to 4 cm/year). For a prime present-day analogue to the micro-continental block collision-accretion, model predictions are compared against the collision between Eratosthenes and Cyprus. Preliminary results show that slab break-off occurs directly after the collision when the plate convergence velocities are less than 2 cm/yr and the mantle lithosphere of the continental block has viscoplastic rheology. On the other hand, there is no relationship between convergence rate and break-off event when the lithospheric mantle rheology is chosen to be plastic. Furthermore, the micro-continental block undergoes considerable extension before continental collision due to the slab pull force, if a viscoplastic rheology is assumed for the mantle lithosphere.

Improving Broader Impacts through Researcher-Educator Partnerships

NASA Astrophysics Data System (ADS)

Timm, K.; Warburton, J.; Larson, A. M.

2009-12-01

Since 1998, the Arctic Research Consortium of the United States (ARCUS) has designed and implemented successful Teacher Research Experience (TRE) programs enabling teachers to work directly with polar scientists in the field and bring their experience back to their classrooms and communities. The PolarTREC TRE model, administered during the International Polar Year (2007-2009), is most effective, exhibiting far-reaching broader impacts when ideas are shared, each partners’ expertise is respected, and both work toward the common goal of delivering high-quality information. Between 2004 and 2009, ARCUS has selected, trained, and supported 77 teachers on polar teacher research experiences. Although a limited number of teachers are able to participate in a field experience, selected teachers have expertise in translating research approaches and results into widely shared learning tools and programs. Between 2007-2009, PolarTREC teachers have constructed nearly 100 classroom lesson plans and activities as a result of their experience. Selected teachers are usually well connected within their schools, communities, and professions, bringing the science to numerous followers during their expedition. Live events with teachers and researchers in the field have attracted over 11,000 participants, primarily K-12 students. The PolarTREC TRE Model includes numerous methods to support outreach activities while teachers and researchers are in the field. These include web-based communications, journals, discussion forums, multimedia, and live events—all easily replicable activities with the potential to affect large numbers of people. In addition, the TRE experience continues to produce broader impacts far into the future of the teacher and researcher’s careers through ongoing communications, presentations at professional conferences, and continued support of each other’s work through activities including classroom visits, joint proposal development, and much more. Preliminary evaluation data from 45 teachers and their researchers indicate overwhelming satisfaction with their participation in PolarTREC. Researchers have expressed that both their research and the scientific process have benefited from the inclusion of a teacher on their team. The need to explain their research and “boil it down to the raw essence” helped the research teams see how their work fits into the bigger world picture, communicate outside their scientific discipline, and present their science effectively to diverse public audiences. Although researcher participation in programs like PolarTREC provides a clear and sometimes “easy” route to fulfilling broader impacts, many of the program activities and best practices are documented and can be applied by scientists to their research activities within any discipline or location. Well-tested practices, lessons learned, and preliminary evaluation results from the administration of PolarTREC will be shared widely so that broader impacts can be fulfilled, scientific research can be improved, and important polar science will be shared with diverse student and public audiences. For more information, contact ARCUS at: info@polartrec.com or 907-474-1600.

Modelling the Centers of Galaxies

NASA Technical Reports Server (NTRS)

Smith, B. F.; Miller, R. H.; Young, Richard E. (Technical Monitor)

1997-01-01

The key to studying central regions by means of nobody numerical experiments is to concentrate on the central few parsecs of a galaxy, replacing the remainder of the galaxy by a suitable boundary condition, rather after the manner in which stellar interiors can be studied without a detailed stellar atmosphere by replacing the atmosphere with a boundary condition. Replacements must be carefully designed because the long range gravitational force means that the core region is sensitive to mass outside that region and because particles can exchange between the outer galaxy and the core region. We use periodic boundary conditions, coupled with an iterative procedure to generate initial particle loads in isothermal equilibrium. Angular momentum conservation is ensured for problems including systematic rotation by a circular reflecting boundary and by integrating in a frame that rotates with the mean flow. Mass beyond the boundary contributes to the gravitational potential, but does not participate in the dynamics. A symplectic integration scheme has been developed for rotating coordinate systems. This combination works well, leading to robust configurations. Some preliminary results with this combination show that: (1) Rotating systems are extremely sensitive to non-axisymmetric external potentials, and (2) that a second core, orbiting near the main core (like the M31 second core system), shows extremely rapid orbital decay. The experimental setups will be discussed, along with preliminary results.

A numerical approach to model and predict the energy absorption and crush mechanics within a long-fiber composite crush tube

NASA Astrophysics Data System (ADS)

Pickett, Leon, Jr.

Past research has conclusively shown that long fiber structural composites possess superior specific energy absorption characteristics as compared to steel and aluminum structures. However, destructive physical testing of composites is very costly and time consuming. As a result, numerical solutions are desirable as an alternative to experimental testing. Up until this point, very little numerical work has been successful in predicting the energy absorption of composite crush structures. This research investigates the ability to use commercially available numerical modeling tools to approximate the energy absorption capability of long-fiber composite crush tubes. This study is significant because it provides a preliminary analysis of the suitability of LS-DYNA to numerically characterize the crushing behavior of a dynamic axial impact crushing event. Composite crushing theory suggests that there are several crushing mechanisms occurring during a composite crush event. This research evaluates the capability and suitability of employing, LS-DYNA, to simulate the dynamic crush event of an E-glass/epoxy cylindrical tube. The model employed is the composite "progressive failure model", a much more limited failure model when compared to the experimental failure events which naturally occur. This numerical model employs (1) matrix cracking, (2) compression, and (3) fiber breakage failure modes only. The motivation for the work comes from the need to reduce the significant cost associated with experimental trials. This research chronicles some preliminary efforts to better understand the mechanics essential in pursuit of this goal. The immediate goal is to begin to provide deeper understanding of a composite crush event and ultimately create a viable alternative to destructive testing of composite crush tubes.

Applications of numerical optimization methods to helicopter design problems: A survey

NASA Technical Reports Server (NTRS)

Miura, H.

1984-01-01

A survey of applications of mathematical programming methods is used to improve the design of helicopters and their components. Applications of multivariable search techniques in the finite dimensional space are considered. Five categories of helicopter design problems are considered: (1) conceptual and preliminary design, (2) rotor-system design, (3) airframe structures design, (4) control system design, and (5) flight trajectory planning. Key technical progress in numerical optimization methods relevant to rotorcraft applications are summarized.

Applications of numerical optimization methods to helicopter design problems - A survey

NASA Technical Reports Server (NTRS)

Miura, H.

1985-01-01

A survey of applications of mathematical programming methods is used to improve the design of helicopters and their components. Applications of multivariable search techniques in the finite dimensional space are considered. Five categories of helicopter design problems are considered: (1) conceptual and preliminary design, (2) rotor-system design, (3) airframe structures design, (4) control system design, and (5) flight trajectory planning. Key technical progress in numerical optimization methods relevant to rotorcraft applications are summarized.

Applications of numerical optimization methods to helicopter design problems - A survey

NASA Technical Reports Server (NTRS)

Miura, H.

1984-01-01

A survey of applications of mathematical programming methods is used to improve the design of helicopters and their components. Applications of multivariable search techniques in the finite dimensional space are considered. Five categories of helicopter design problems are considered: (1) conceptual and preliminary design, (2) rotor-system design, (3) airframe structures design, (4) control system design, and (5) flight trajectory planning. Key technical progress in numerical optimization methods relevant to rotorcraft applications are summarized.

Coupling artificial intelligence and numerical computation for engineering design (Invited paper)

NASA Astrophysics Data System (ADS)

Tong, S. S.

1986-01-01

The possibility of combining artificial intelligence (AI) systems and numerical computation methods for engineering designs is considered. Attention is given to three possible areas of application involving fan design, controlled vortex design of turbine stage blade angles, and preliminary design of turbine cascade profiles. Among the AI techniques discussed are: knowledge-based systems; intelligent search; and pattern recognition systems. The potential cost and performance advantages of an AI-based design-generation system are discussed in detail.

Preliminary Flight Results of the Microelectronics and Photonics Test Bed: NASA DR1773 Fiber Optic Data Bus Experiment

NASA Technical Reports Server (NTRS)

Jackson, George L.; LaBel, Kenneth A.; Marshall, Cheryl; Barth, Janet; Seidleck, Christina; Marshall, Paul

1998-01-01

NASA Goddard Spare Flight Center's (GSFC) Dual Rate 1773 (DR1773) Experiment on the Microelectronic and Photonic Test Bed (MPTB) has provided valuable information on the performance of the AS 1773 fiber optic data bus in the space radiation environment. Correlation of preliminary experiment data to ground based radiation test results show the AS 1773 bus is employable in future spacecraft applications requiring radiation tolerant communication links.

Design, experimental analysis, and unsteady Reynolds-averaged Navier-Stokes simulation of laboratory-scale counter-rotating vertical-axis turbines in marine environment

NASA Astrophysics Data System (ADS)

Doan, Minh; Padricelli, Claudrio; Obi, Shinnosuke; Totsuka, Yoshitaka

2017-11-01

We present the torque and power measurement of laboratory-scale counter-rotating vertical-axis hydrokinetic turbines, built around a magnetic hysteresis brake as the speed controller and a Hall-effect sensor as the rotational speed transducer. A couple of straight-three-bladed turbines were linked through a transmission of spur gears and timing pulleys and coupled to the electronic instrumentation via flexible shaft couplers. A total of 8 experiments in 2 configurations were conducted in the water channel facility (4-m long, 0.3-m wide, and 0.15-m deep). Power generation of the turbines (0.06-m rotor diameter) was measured and compared with that of single turbines of the same size. The wakes generated by these experiments were also measured by particle image velocimetry (PIV) and numerically simulated by unsteady Reynolds-averaged Navier-Stokes (URANS) simulation using OpenFOAM. Preliminary results from wake measurement indicated the mechanism of enhanced power production behind the counter-rotating configuration of vertical-axis turbines. Current address: Politecnico di Milano.

Hemispheric asymmetries and gender influence Rembrandt's portrait orientations.

PubMed

Schirillo, J A

2000-01-01

For centuries painters have predominantly painted portraits with the model's left-cheek facing the viewer. This has been even more prevalent with females ( approximately 68%) than males ( approximately 56%). Numerous portraits painted by Rembrandt typify this unexplained phenomenon. In a preliminary experiment, subjects judged 24 emotional and social character traits in 20 portraits by Rembrandt. A factor analysis revealed that females with their left cheek exposed were judged to be much less socially appealing than less commonly painted right-cheeked females. Conversely, the more commonly painted right-cheeked males were judged to be more socially appealing than either left-cheeked males or females facing either direction. It is hypothesized that hemispheric asymmetries regulating emotional facial displays of approach and avoidance influenced the side of the face Rembrandt's models exposed due to prevailing social norms. A second experiment had different subjects judge a different collection of 20 portraits by Rembrandt and their mirror images. Mirror-reversed images produced the same pattern of results as their original orientation counterparts. Consequently, hemispheric asymmetries that specify the emotional expression on each side of the face are posited to account for the obtained results.

Some experiences in aircraft aeroelastic design using Preliminary Aeroelastic Design of Structures (PAD)

NASA Technical Reports Server (NTRS)

Radovcich, N. A.

1984-01-01

The design experience associated with a benchmark aeroelastic design of an out of production transport aircraft is discussed. Current work being performed on a high aspect ratio wing design is reported. The Preliminary Aeroelastic Design of Structures (PADS) system is briefly summarized and some operational aspects of generating the design in an automated aeroelastic design environment are discussed.

Teaching Note--Description and Preliminary Evaluation of a Modified College Experience for Adults with Intellectual and Developmental Disabilities

ERIC Educational Resources Information Center

Remis, Kimberly; Moore, Crystal Dea; Pichardo, Julia; Rosario, Zuliany; Moore, Jeffrey Palmer

2017-01-01

This article describes the implementation and preliminary evaluation of a modified college experience for adults with intellectual and developmental disabilities (IDD) at a small liberal arts college. To increase social work students' interest in working with this population and access of people with IDD to higher education, Bridges to Skidmore…

Numerical investigation of supersonic turbulent boundary layers with high wall temperature

NASA Technical Reports Server (NTRS)

Guo, Y.; Adams, N. A.

1994-01-01

A direct numerical approach has been developed to simulate supersonic turbulent boundary layers. The mean flow quantities are obtained by solving the parabolized Reynolds-averaged Navier-Stokes equations (globally). Fluctuating quantities are computed locally with a temporal direct numerical simulation approach, in which nonparallel effects of boundary layers are partially modeled. Preliminary numerical results obtained at the free-stream Mach numbers 3, 4.5, and 6 with hot-wall conditions are presented. Approximately 5 million grid points are used in all three cases. The numerical results indicate that compressibility effects on turbulent kinetic energy, in terms of dilatational dissipation and pressure-dilatation correlation, are small. Due to the hot-wall conditions the results show significant low Reynolds number effects and large streamwise streaks. Further simulations with a bigger computational box or a cold-wall condition are desirable.

Preliminary design of flight hardware for two-phase fluid research

NASA Technical Reports Server (NTRS)

Hustvedt, D. C.; Oonk, R. L.

1982-01-01

This study defined the preliminary designs of flight software for the Space Shuttle Orbiter for three two-phase fluid research experiments: (1) liquid reorientation - to study the motion of liquid in tanks subjected to small accelerations; (2) pool boiling - to study low-gravity boiling from horizontal cylinders; and (3) flow boiling - to study low-gravity forced flow boiling heat transfer and flow phenomena in a heated horizontal tube. The study consisted of eight major tasks: reassessment of the existing experiment designs, assessment of the Spacelab facility approach, assessment of the individual carry-on approach, selection of the preferred approach, preliminary design of flight hardware, safety analysis, preparation of a development plan, estimates of detailed design, fabrication and ground testing costs. The most cost effective design approach for the experiments is individual carry-ons in the Orbiter middeck. The experiments were designed to fit into one or two middeck lockers. Development schedules for the detailed design, fabrication and ground testing ranged from 15 1/2 to 18 months. Minimum costs (in 1981 dollars) ranged from $463K for the liquid reorientation experiment to $998K for the pool boiling experiment.

Nonlocal nonlinear refraction in Hibiscus sabdariffa with large phase shifts.

PubMed

Ramírez-Martínez, D; Alvarado-Méndez, E; Trejo-Durán, M; Vázquez-Guevara, M A

2014-10-20

In this work we present a study of nonlinear optical properties in organic materials (hibiscus sabdariffa). Our results demonstrate that the medium exhibits a highly nonlocal nonlinear response. We show preliminary numerical results of the transmittance as nonlocal response by considering, simultaneously, the nonlinear absorption and refraction in media. Numerical results are accord to measurement obtained by Z- scan technique where we observe large phase shifts. We also analyze the far field diffraction ring patterns of the sample.

Cosmic strings - A problem or a solution?

NASA Technical Reports Server (NTRS)

Bennett, David P.; Bouchet, Francois R.

1988-01-01

The most fundamental issue in the theory of cosmic strings is addressed by means of Numerical Simulations: the existence of a scaling solution. The resolution of this question will determine whether cosmic strings can form the basis of an attractive theory of galaxy formation or prove to be a cosmological disaster like magnetic monopoles or domain walls. After a brief discussion of our numerical technique, results are presented which, though still preliminary, offer the best support to date of this scaling hypothesis.

Preliminary numerical analysis of improved gas chromatograph model

NASA Technical Reports Server (NTRS)

Woodrow, P. T.

1973-01-01

A mathematical model for the gas chromatograph was developed which incorporates the heretofore neglected transport mechanisms of intraparticle diffusion and rates of adsorption. Because a closed-form analytical solution to the model does not appear realizable, techniques for the numerical solution of the model equations are being investigated. Criteria were developed for using a finite terminal boundary condition in place of an infinite boundary condition used in analytical solution techniques. The class of weighted residual methods known as orthogonal collocation is presently being investigated and appears promising.

Numerical Analysis on the Rheology of Martian Lobate Debris Aprons

NASA Astrophysics Data System (ADS)

Li, H.; Jing, H.; Zhang, H.; Shi, Y.

2011-10-01

Occurrence of ice in Martian subsurface is indicated by landforms such as lobate debris aprons (LDAs), concentric crater fills, and softened terrains. We used a three dimensional non-Newtonian viscous finite element model to investigate the behavior of ice-rock mixtures numerically. Our preliminary simulation results show that when the volume of rock is less than 40%, the rheology of the mixture is dominated by ice, and there exists a brittle-ductile transition when ice fraction reaches a certain value.

Simulation of a Single-Element Lean-Direct Injection Combustor Using Arbitrary Polyhedral Mesh

NASA Technical Reports Server (NTRS)

Wey, Thomas; Liu, Nan-Suey

2012-01-01

This paper summarizes procedures of generating the arbitrary polyhedral mesh as well as presents sample results from its application to the numerical solution of a single-element LDI combustor using a preliminary version of the new OpenNCC.

Analytical modeling of the dynamics of brushless dc motors for aerospace applications: A conceptual framework

NASA Technical Reports Server (NTRS)

Demerdash, N. A. O.

1976-01-01

The modes of operation of the brushless d.c. machine and its corresponding characteristics (current flow, torque-position, etc.) are presented. The foundations and basic principles on which the preliminary numerical model is based, are discussed.

Preliminary orbit determination for lunar satellites.

NASA Technical Reports Server (NTRS)

Lancaster, E. R.

1973-01-01

Methods for the determination of orbits of artificial lunar satellites from earth-based range rate measurements developed by Koskela (1964) and Bateman et al. (1966) are simplified and extended to include range measurements along with range rate measurements. For illustration, a numerical example is presented.

Preliminary design study for an atomospheric science facility

NASA Technical Reports Server (NTRS)

Hutchison, R.

1972-01-01

The activities and results of the Atmospheric Science Facility preliminary design study are reported. The objectives of the study were to define the scientific goals, to determine the range of experiment types, and to develop the preliminary instrument design requirements for a reusable, general purpose, optical research facility for investigating the earth's atmosphere from a space shuttle orbital vehicle.

["Soiuz-Apollo" experimental flight. Preliminary results of medicobiological studies, carried out during the flight of "Soiuz-19" spaceship].

PubMed

Vorob'ev, E I; Gazenko, O G; Gurovskiĭ, N N; Nefedov, Iu G; Egorov, B B

1976-01-01

The paper presents brief information on the Apollo-Soyuz test mission, its program biomedical investigations to be carried out in flight and specific medical aspects. It discusses the main tasks of the joint US-USSR experiments and Soviet experiments. It gives and analyzes preliminary results of medical monitoring and postflight examinations of the crew members.

A research experiment on facilitation and formation of joint research and development programs between government, industry, and universities: Overview, preliminary findings, and observations

NASA Technical Reports Server (NTRS)

Shariq, Syed Z.

1992-01-01

Presented is an overview of an experiment to explore the free-market approach to public-private collaboration through the development and implementation of a joint venture mechanism to enable formation of R&D projects between government, industry and academia. Some preliminary results related to time-to-commercialization and economic competitiveness are discussed.

Laboratory Measurements of the Sound Generated by Breaking Waves

DTIC Science & Technology

1991-12-01

these techniques have not yet proven effective for studying the dynamics of breaking. The primary motivation for the research 3 presented in this...experiments described in this thesis were motivated by the fact that these preliminary experiments described above demonstrated that the simple I...1991. The research was motivated by the fact that preliminary measurements by Melville, Loewen, Felizardo, Jessup and Buckingham (1988) demonstrated

Numerical experiments of dynamical processes during the 2011-2013 surge of the Bering-Bagley Glacier System, using a full-Stokes finite element model

NASA Astrophysics Data System (ADS)

Trantow, Thomas

The Bering-Bagley Glacial System (BBGS) is the largest glacier system outside of the Greenland and Antarctic ice sheets, and is the Earth's largest surge-type glacier. Surging is one of three types of glacial acceleration and the least understood one. Understanding glacial acceleration is paramount when trying to explain ice discharge to the oceans and the glacial contribution to sea-level rise, yet there are currently no numerical glacial models that account for surging. The recent 2011-2013 surge of the BBGS provides a rare opportunity to study the surge process through observations and the subsequent data analysis and numerical modeling. Using radar, altimeter, and image data collected from airborne and satellite missions, various descriptions of ice geometry are created at different times throughout the surge. Using geostatistical estimation techniques including variography and ordinary kriging, surface and bedrock Digital Elevation Maps (DEMs) are derived. A time series analysis of elevation change during the current surge is then conducted and validated using a complete error analysis along with airborne observations. The derived DEMs are then used as inputs to a computer simulated model of glacier dynamics in the BBGS. Using the Finite Element software Elmer/Ice, a full-Stokes simulation, with Glen's flow law for temperate ice, is created for numerical experiments. With consideration of free surface evolution, glacial hydrology and surface mass balance, the model is able to predict a variety of field variables including velocity, stress, strain-rate, pressure and surface elevation change at any point forward in time. These outputs are compared and validated using observational data such as CryoSat-2 altimetry, airborne field data, imagery and previous detailed analysis of the BBGS. Preliminary results reveal that certain surge phenomena such as surface elevation changes, surge progression and locations at which the surge starts, can be recreated using the current model. Documentation of the effects that altering glaciological parameters and boundary conditions have on ice rheology in a large complex glacial system comes as secondary result. Simulations have yet to reveal any quasi-cyclic behavior or natural surge initiation.

[Peloid therapy. An overview of the empirical status and evidence of mud therapy].

PubMed

Beer, A-M; Fetaj, S; Lange, U

2013-08-01

Numerous peloids for balneotherapy are currently available but in terms of effects and efficacy therapeutic peat has been studied best. Recent studies revealed that both thermal and physical effects of therapeutic peat are comparable and synergistic. The thermal effects of all types of peat used are approximately the same but chemical effects differ. These results have to been taken into account in future peloid analyses and indications and contraindications of mud therapy have to be reviewed in this respect. Some hypothetical aspects of these chemical effects have to be investigated in future clinical studies but clinical experience with mud therapy allows preliminary conclusions to be drawn. This statement is especially supported by recent molecular investigations. Knowledge about the chemical effects is also necessary for planning, defining and designing clinical studies and patients groups. Exemplarily, the therapeutic use of peat in rheumatic diseases and for fertility treatment will be demonstrated.

Analysis of the charging of the SCATHA (P78-2) satellite

NASA Technical Reports Server (NTRS)

Stannard, P. R.; Katz, I.; Mandell, M. J.; Cassidy, J. J.; Parks, D. E.; Rotenberg, M.; Steen, P. G.

1980-01-01

The charging of a large object in polar Earth orbit was investigated in order to obtain a preliminary indication of the response of the shuttle orbiter to such an environment. Two NASCAP (NASA Charging Analyzer Program) models of SCATHA (Satellite Charging at High Altitudes) were used in simulations of charging events. The properties of the satellite's constituent materials were compiled and representations of the experimentally observed plasma spectra were constructed. Actual charging events, as well as those using test environments, were simulated. Numerical models for the simulation of particle emitters and detectors were used to analyze the operation of these devices onboard SCATHA. The effect of highly charged surface regions on the charging conductivity within a photosheath was used to interpret results from the onboard electric field experiment. Shadowing calculations were carried out for the satellite and a table of effective illuminated areas was compiled.

Experimental Investigation of the Formation of Complex Craters

NASA Astrophysics Data System (ADS)

Martellato, E.; Dörfler, M. A.; Schuster, B.; Wünnemman, K.; Kenkmann, T.

2017-09-01

The formation of complex impact craters is still poorly understood, because standard material models fail to explain the gravity-driven collapse at the observed size-range of a bowl-shaped transient crater into a flat-floored crater structure with a central peak or ring and terraced rim. To explain such a collapse the so-called Acoustic Fluidization (AF) model has been proposed. The AF assumes that heavily fractured target rocks surrounding the transient crater are temporarily softened by an acoustic field in the wake of an expanding shock wave generated upon impact. The AF has been successfully employed in numerous modeling studies of complex crater formation; however, there is no clear relationship between model parameters and observables. In this study, we present preliminary results of laboratory experiments aiming at relating the AF parameters to observables such as the grain size, average wave length of the acoustic field and its decay time τ relative to the crater formation time.

Premixed autoignition in compressible turbulence

NASA Astrophysics Data System (ADS)

Konduri, Aditya; Kolla, Hemanth; Krisman, Alexander; Chen, Jacqueline

2016-11-01

Prediction of chemical ignition delay in an autoignition process is critical in combustion systems like compression ignition engines and gas turbines. Often, ignition delay times measured in simple homogeneous experiments or homogeneous calculations are not representative of actual autoignition processes in complex turbulent flows. This is due the presence of turbulent mixing which results in fluctuations in thermodynamic properties as well as chemical composition. In the present study the effect of fluctuations of thermodynamic variables on the ignition delay is quantified with direct numerical simulations of compressible isotropic turbulence. A premixed syngas-air mixture is used to remove the effects of inhomogeneity in the chemical composition. Preliminary results show a significant spatial variation in the ignition delay time. We analyze the topology of autoignition kernels and identify the influence of extreme events resulting from compressibility and intermittency. The dependence of ignition delay time on Reynolds and turbulent Mach numbers is also quantified. Supported by Basic Energy Sciences, Dept of Energy, United States.

Toward performance portability of the Albany finite element analysis code using the Kokkos library

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

Demeshko, Irina; Watkins, Jerry; Tezaur, Irina K.

Performance portability on heterogeneous high-performance computing (HPC) systems is a major challenge faced today by code developers: parallel code needs to be executed correctly as well as with high performance on machines with different architectures, operating systems, and software libraries. The finite element method (FEM) is a popular and flexible method for discretizing partial differential equations arising in a wide variety of scientific, engineering, and industrial applications that require HPC. This paper presents some preliminary results pertaining to our development of a performance portable implementation of the FEM-based Albany code. Performance portability is achieved using the Kokkos library. We presentmore » performance results for the Aeras global atmosphere dynamical core module in Albany. Finally, numerical experiments show that our single code implementation gives reasonable performance across three multicore/many-core architectures: NVIDIA General Processing Units (GPU’s), Intel Xeon Phis, and multicore CPUs.« less

Toward performance portability of the Albany finite element analysis code using the Kokkos library

DOE PAGES

Demeshko, Irina; Watkins, Jerry; Tezaur, Irina K.; ...

2018-02-05

Performance portability on heterogeneous high-performance computing (HPC) systems is a major challenge faced today by code developers: parallel code needs to be executed correctly as well as with high performance on machines with different architectures, operating systems, and software libraries. The finite element method (FEM) is a popular and flexible method for discretizing partial differential equations arising in a wide variety of scientific, engineering, and industrial applications that require HPC. This paper presents some preliminary results pertaining to our development of a performance portable implementation of the FEM-based Albany code. Performance portability is achieved using the Kokkos library. We presentmore » performance results for the Aeras global atmosphere dynamical core module in Albany. Finally, numerical experiments show that our single code implementation gives reasonable performance across three multicore/many-core architectures: NVIDIA General Processing Units (GPU’s), Intel Xeon Phis, and multicore CPUs.« less

Microwave propagation and absorption and its thermo-mechanical consequences in heterogeneous rocks.

PubMed

Meisels, R; Toifl, M; Hartlieb, P; Kuchar, F; Antretter, T

2015-02-10

A numerical analysis in a two-component model rock is presented including the propagation and absorption of a microwave beam as well as the microwave-induced temperature and stress distributions in a consistent way. The analyses are two-dimensional and consider absorbing inclusions (discs) in a non-absorbing matrix representing the model of a heterogeneous rock. The microwave analysis (finite difference time domain - FDTD) is performed with values of the dielectric permittivity typical for hard rocks. Reflections at the discs/matrix interfaces and absorption in the discs lead to diffuse scattering with up to 20% changes of the intensity in the main beam compared to a homogeneous model rock. The subsequent thermo-mechanical finite element (FE) analysis indicates that the stresses become large enough to initiate damage. The results are supported by preliminary experiments on hard rock performed at 2.45 GHz.

Double-Referential Holography and Spatial Quadrature Amplitude Modulation

NASA Astrophysics Data System (ADS)

Zukeran, Keisuke; Okamoto, Atsushi; Takabayashi, Masanori; Shibukawa, Atsushi; Sato, Kunihiro; Tomita, Akihisa

2013-09-01

We proposed a double-referential holography (DRH) that allows phase-detection without external additional beams. In the DRH, phantom beams, prepared in the same optical path as signal beams and preliminary multiplexed in a recording medium along with the signal, are used to produce interference fringes on an imager for converting a phase into an intensity distribution. The DRH enables stable and high-accuracy phase detection independent of the fluctuations and vibrations of the optical system owing to medium shift and temperature variation. Besides, the collinear arrangement of the signal and phantom beams leads to the compactness of the optical data storage system. We conducted an experiment using binary phase modulation signals for verifying the DRH operation. In addition, 38-level spatial quadrature amplitude modulation signals were successfully reproduced with the DRH by numerical simulation. Furthermore, we verified that the distributed phase-shifting method moderates the dynamic range consumption for the exposure of phantom beams.

Older lesbian sexuality: identity, sexual behavior, and the impact of aging.

PubMed

Averett, Paige; Yoon, Intae; Jenkins, Carol L

2012-01-01

In response to the very limited and mostly outdated literature on older lesbian sexuality, this exploratory study examined older lesbian sexual identity, romantic relationships, the impact of aging, and experiences of discrimination within these contexts. Utilizing an online survey that recruited via numerous online lesbian communities and snowball sampling, 456 lesbians over the age of 50 responded to closed, Likert scale, and open-ended questions that provided a preliminary understanding of older lesbian sexuality. The results indicated that older lesbians have experienced fluidity in past romantic and sexual relationships, as well as in erotic fantasies, despite strong identification with being lesbian. The findings also indicate a decreased focus on sexuality in the context of relationships, with more focus on stability and continuity. Future research is needed that provides greater specificity and detail about older lesbian conceptions of sexual behavior and sexual identity labels, as well as specific sexual behaviors.

Progress on LMJ targets for ignition

NASA Astrophysics Data System (ADS)

Cherfils-Clérouin, C.; Boniface, C.; Bonnefille, M.; Dattolo, E.; Galmiche, D.; Gauthier, P.; Giorla, J.; Laffite, S.; Liberatore, S.; Loiseau, P.; Malinie, G.; Masse, L.; Masson-Laborde, P. E.; Monteil, M. C.; Poggi, F.; Seytor, P.; Wagon, F.; Willien, J. L.

2009-12-01

Targets designed to produce ignition on the Laser Megajoule (LMJ) are being simulated in order to set specifications for target fabrication. The LMJ experimental plans include the attempt of ignition and burn of an ICF capsule with 160 laser beams, delivering up to 1.4 MJ and 380 TW. New targets needing reduced laser energy with only a small decrease in robustness have then been designed for this purpose. Working specifically on the coupling efficiency parameter, i.e. the ratio of the energy absorbed by the capsule to the laser energy, has led to the design of a rugby-ball shaped cocktail hohlraum; with these improvements, a target based on the 240-beam A1040 capsule can be included in the 160-beam laser energy-power space. Robustness evaluations of these different targets shed light on critical points for ignition, which can trade off by tightening some specifications or by preliminary experimental and numerical tuning experiments.

High energy beam impact tests on a LHC tertiary collimator at the CERN high-radiation to materials facility

NASA Astrophysics Data System (ADS)

Cauchi, Marija; Aberle, O.; Assmann, R. W.; Bertarelli, A.; Carra, F.; Cornelis, K.; Dallocchio, A.; Deboy, D.; Lari, L.; Redaelli, S.; Rossi, A.; Salvachua, B.; Mollicone, P.; Sammut, N.

2014-02-01

The correct functioning of a collimation system is crucial to safely operate highly energetic particle accelerators, such as the Large Hadron Collider (LHC). The requirements to handle high intensity beams can be demanding. In this respect, investigating the consequences of LHC particle beams hitting tertiary collimators (TCTs) in the experimental regions is a fundamental issue for machine protection. An experimental test was designed to investigate the robustness and effects of beam accidents on a fully assembled collimator, based on accident scenarios in the LHC. This experiment, carried out at the CERN High-Radiation to Materials (HiRadMat) facility, involved 440 GeV proton beam impacts of different intensities on the jaws of a horizontal TCT. This paper presents the experimental setup and the preliminary results obtained, together with some first outcomes from visual inspection and a comparison of such results with numerical simulations.

Phase space manipulation in high-brightness electron beams

NASA Astrophysics Data System (ADS)

Rihaoui, Marwan M.

Electron beams have a wide range of applications, including discovery science, medicine, and industry. Electron beams can also be used to power next-generation, high-gradient electron accelerators. The performances of some of these applications could be greatly enhanced by precisely tailoring the phase space distribution of the electron beam. The goal of this dissertation is to explore some of these phase space manipulations. We especially focus on transformations capable of tailoring the beam current distribution. Specifically, we investigate a beamline exchanging phase space coordinates between the horizontal and longitudinal degrees of freedom. The key components necessary for this beamline were constructed and tested. The preliminary beamline was used as a singleshot phase space diagnostics and to produce a train of picoseconds electron bunches. We also investigate the use of multiple electron beams to control the transverse focusing. Our numerical and analytical studies are supplemented with experiments performed at the Argonne Wakefield Accelerator.

Development of a Hybrid RANS/LES Method for Compressible Mixing Layer Simulations

NASA Technical Reports Server (NTRS)

Georgiadis, Nicholas J.; Alexander, J. Iwan D.; Reshotko, Eli

2001-01-01

A hybrid method has been developed for simulations of compressible turbulent mixing layers. Such mixing layers dominate the flows in exhaust systems of modem day aircraft and also those of hypersonic vehicles currently under development. The hybrid method uses a Reynolds-averaged Navier-Stokes (RANS) procedure to calculate wall bounded regions entering a mixing section, and a Large Eddy Simulation (LES) procedure to calculate the mixing dominated regions. A numerical technique was developed to enable the use of the hybrid RANS/LES method on stretched, non-Cartesian grids. The hybrid RANS/LES method is applied to a benchmark compressible mixing layer experiment. Preliminary two-dimensional calculations are used to investigate the effects of axial grid density and boundary conditions. Actual LES calculations, performed in three spatial directions, indicated an initial vortex shedding followed by rapid transition to turbulence, which is in agreement with experimental observations.

How Much Can We Learn from a Single Chromatographic Experiment? A Bayesian Perspective.

PubMed

Wiczling, Paweł; Kaliszan, Roman

2016-01-05

In this work, we proposed and investigated a Bayesian inference procedure to find the desired chromatographic conditions based on known analyte properties (lipophilicity, pKa, and polar surface area) using one preliminary experiment. A previously developed nonlinear mixed effect model was used to specify the prior information about a new analyte with known physicochemical properties. Further, the prior (no preliminary data) and posterior predictive distribution (prior + one experiment) were determined sequentially to search towards the desired separation. The following isocratic high-performance reversed-phase liquid chromatographic conditions were sought: (1) retention time of a single analyte within the range of 4-6 min and (2) baseline separation of two analytes with retention times within the range of 4-10 min. The empirical posterior Bayesian distribution of parameters was estimated using the "slice sampling" Markov Chain Monte Carlo (MCMC) algorithm implemented in Matlab. The simulations with artificial analytes and experimental data of ketoprofen and papaverine were used to test the proposed methodology. The simulation experiment showed that for a single and two randomly selected analytes, there is 97% and 74% probability of obtaining a successful chromatogram using none or one preliminary experiment. The desired separation for ketoprofen and papaverine was established based on a single experiment. It was confirmed that the search for a desired separation rarely requires a large number of chromatographic analyses at least for a simple optimization problem. The proposed Bayesian-based optimization scheme is a powerful method of finding a desired chromatographic separation based on a small number of preliminary experiments.

Computational Studies of Magnetic Nozzle Performance

NASA Technical Reports Server (NTRS)

Ebersohn, Frans H.; Longmier, Benjamin W.; Sheehan, John P.; Shebalin, John B.; Raja, Laxminarayan

2013-01-01

An extensive literature review of magnetic nozzle research has been performed, examining previous work, as well as a review of fundamental principles. This has allow us to catalog all basic physical mechanisms which we believe underlie the thrust generation process. Energy conversion mechanisms include the approximate conservation of the magnetic moment adiabatic invariant, generalized hall and thermoelectric acceleration, swirl acceleration, thermal energy transformation into directed kinetic energy, and Joule heating. Momentum transfer results from the interaction of the applied magnetic field with currents induced in the plasma plume., while plasma detachment mechanisms include resistive diffusion, recombination and charge exchange collisions, magnetic reconnection, loss of adiabaticity, inertial forces, current closure, and self-field detachment. We have performed a preliminary study of Hall effects on magnetic nozzle jets with weak guiding magnetic fields and weak expansions (p(sub jet) approx. = P(sub background)). The conclusion from this study is that the Hall effect creates an azimuthal rotation of the plasma jet and, more generally, creates helical structures in the induced current, velocity field, and magnetic fields. We have studied plasma jet expansion to near vacuum without a guiding magnetic field, and are presently including a guiding magnetic field using a resistive MHD solver. This research is progressing toward the implementation of a full generalized Ohm's law solver. In our paper, we will summarize the basic principle, as well as the literature survey and briefly review our previous results. Our most recent results at the time of submittal will also be included. Efforts are currently underway to construct an experiment at the University of Michigan Plasmadynamics and Electric Propulsion Laboratory (PEPL) to study magnetic nozzle physics for a RF-thruster. Our computational study will work directly with this experiment to validate the numerical model, in order to study magnetic nozzle physics and optimize magnetic nozzle design. Preliminary results from the PEPL experiment will also be presented.

Simulation of the Impact of New Aircraft-and Satellite-based Ocean Surface Wind Measurements on Wind Analyses and Numerical Forecasts

NASA Technical Reports Server (NTRS)

Miller, TImothy; Atlas, Robert; Black, Peter; Chen, Shuyi; Jones, Linwood; Ruf, Chris; Uhlhorn, Eric; Gamache, John; Amarin, Ruba; El-Nimri, Salem;

Natural fiber production, harvesting, and preliminary processing: options and opportunities

USDA-ARS?s Scientific Manuscript database

The utilization of natural fibers and plant oils in bio-products introduces numerous logistical challenges not typically encountered with non-agricultural resources. Once it has been determined that a plant material is suitable for commercial development, the production, harvesting, and processing s...

Preliminary study on radio-chemo-induced oral mucositis and low level laser therapy

NASA Astrophysics Data System (ADS)

Merigo, Elisabetta; Fontana, Matteo; Fornaini, Carlo; Clini, Fabio; Cella, Luigi; Vescovi, Paolo; Oppici, Aldo

2012-09-01

Background: Oral mucositis remains one of the most common and troubling side effects of antineoplastic radiation and drug therapy: its incidence in onco-hematological radio-chemotreated patients is variable between 50 and 100% and its impact on this populations is directly linked with the experience of intense pain causing reduction and modification of therapy regimens, decreased survival rates and increased cost of care. Purpose: Aim of this study is the preliminary evaluation of a Low Level Laser therapy (LLLT) protocol on healing process of oral mucositis and on pain and quality of life of patients experiencing this dramatic side-effect. Materials and methods: Patients were evaluated and treated at the Unita` Operativa Semplice Dipartimentale di Odontostomatologia e Chirurgia Maxillo-Facciale of the Hospital of Piacenza were they were treated for primary disease with protocols of chemotherapy and/or radiotherapy. LLLT protocol was performed with a diode laser (808 nm -XD Smile - Fotona -Slovenia) on a two weeks-6 treatments schedule with power of 0.5 W and application of 30 seconds. Mucositis grading was scored on the basis of WHO classification by two blind operators at each treatment and at 1 and 2 weeks after treatment. Pain and capability of deglutition were described by patients by means questionnaires based on Visual Analogue Scale, Numerical Rating Scale and Quality of Life. Results: A relevant improvement of healing of oral mucositis, in terms of reduction of grading score, and of pain, swallowing discomfort and quality of life was recorded. Discussion and conclusion: Results of this preliminary study are encouraging for the realization of larger studies focused on the application of LLLT protocols in management of radio-chemotreated patients with oral mucositis.

Exploring the Dynamics of a Quantum-Mechanical Compton Generator

NASA Astrophysics Data System (ADS)

Kandes, Martin; Carretero, Ricardo

2017-01-01

In 1913, when American physicist Arthur Compton was an undergraduate, he invented a simple way to measure the rotation rate of the Earth with a tabletop-sized experiment. The experiment consisted of a large diameter circular ring of thin glass tubing filled with water and oil droplets. After placing the ring in a plane perpendicular to the surface of the Earth and allowing the fluid mixture of oil and water to come to rest, he then abruptly rotated the ring, flipping it 180 degrees about an axis passing through its own plane. The result of the experiment was that the water acquired a measurable drift velocity due to the Coriolis effect arising from the daily rotation of the Earth about its own axis. Compton measured this induced drift velocity by observing the motion of the oil droplets in the water with a microscope. This device, which is now named after him, is known as a Compton generator. The fundamental research objective of this project is to explore the dynamics of a quantum-mechanical analogue to the classical Compton generator experiment through the use of numerical simulations. We present our preliminary results on this system and the future direction of the project. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation Grant Number ACI-1053575.

Validation of scintillometer measurements over a heterogeneous landscape: The LITFASS-2009 Experiment

NASA Astrophysics Data System (ADS)

Beyrich, F.; Bange, J.; Hartogensis, O.; Raasch, S.

2009-09-01

The turbulent exchange of heat and water vapour are essential land surface - atmosphere interaction processes in the local, regional and global energy and water cycles. Scintillometry can be considered as the only technique presently available for the quasi-operational experimental determination of area-averaged turbulent fluxes needed to validate the fluxes simulated by regional atmospheric models or derived from satellite images at a horizontal scale of a few kilometres. While scintillometry has found increasing application over the last years, some fundamental issues related to its use still need further investigation. In particular, no studies are known so far to reproduce the path-averaged structure parameters measured by scintillometers by independent measurements or modelling techniques. The LITFASS-2009 field experiment has been performed in the area around the Meteorological Observatory Lindenberg / Richard-Aßmann-Observatory in Germany during summer 2009. It was designed to investigate the spatial (horizontal and vertical) and temporal variability of structure parameters (underlying the scintillometer principle) over moderately heterogeneous terrain. The experiment essentially relied on a coupling of eddy-covariance measurements, scintillometry and airborne measurements with an unmanned autonomous aircraft able to strictly fly along the scintillometer path. Data interpretation will be supported by numerical modelling using a large-eddy simulation (LES) model. The paper will describe the design of the experiment. First preliminary results from the measurements will be presented.

Preliminary estimates of spatially distributed net infiltration and recharge for the Death Valley region, Nevada-California

USGS Publications Warehouse

Hevesi, J.A.; Flint, A.L.; Flint, L.E.

2002-01-01

A three-dimensional ground-water flow model has been developed to evaluate the Death Valley regional flow system, which includes ground water beneath the Nevada Test Site. Estimates of spatially distributed net infiltration and recharge are needed to define upper boundary conditions. This study presents a preliminary application of a conceptual and numerical model of net infiltration. The model was developed in studies at Yucca Mountain, Nevada, which is located in the approximate center of the Death Valley ground-water flow system. The conceptual model describes the effects of precipitation, runoff, evapotranspiration, and redistribution of water in the shallow unsaturated zone on predicted rates of net infiltration; precipitation and soil depth are the two most significant variables. The conceptual model was tested using a preliminary numerical model based on energy- and water-balance calculations. Daily precipitation for 1980 through 1995, averaging 202 millimeters per year over the 39,556 square kilometers area of the ground-water flow model, was input to the numerical model to simulate net infiltration ranging from zero for a soil thickness greater than 6 meters to over 350 millimeters per year for thin soils at high elevations in the Spring Mountains overlying permeable bedrock. Estimated average net infiltration over the entire ground-water flow model domain is 7.8 millimeters per year.To evaluate the application of the net-infiltration model developed on a local scale at Yucca Mountain, to net-infiltration estimates representing the magnitude and distribution of recharge on a regional scale, the net-infiltration results were compared with recharge estimates obtained using empirical methods. Comparison of model results with previous estimates of basinwide recharge suggests that the net-infiltration estimates obtained using this model may overestimate recharge because of uncertainty in modeled precipitation, bedrock permeability, and soil properties for locations such as the Spring Mountains. Although this model is preliminary and uncalibrated, it provides a first approximation of the spatial distribution of net infiltration for the Death Valley region under current climatic conditions.

Analysis of Spatial Autocorrelation for Optimal Observation Network in Korea

NASA Astrophysics Data System (ADS)

Park, S.; Lee, S.; Lee, E.; Park, S. K.

2016-12-01

Many studies for improving prediction of high-impact weather have been implemented, such as THORPEX (The Observing System Research and Predictability Experiment), FASTEX (Fronts and Atlantic Storm-Track Experiment), NORPEX (North Pacific Experiment), WSR/NOAA (Winter Storm Reconnaissance), and DOTSTAR (Dropwindsonde Observations for Typhoon Surveillance near the TAiwan Region). One of most important objectives in these studies is to find effects of observation on forecast, and to establish optimal observation network. However, there are lack of such studies on Korea, although Korean peninsula exhibits a highly complex terrain so it is difficult to predict its weather phenomena. Through building the future optimal observation network, it is necessary to increase utilization of numerical weather prediction and improve monitoring·tracking·prediction skills of high-impact weather in Korea. Therefore, we will perform preliminary study to understand the spatial scale for an expansion of observation system through Spatial Autocorrelation (SAC) analysis. In additions, we will develop a testbed system to design an optimal observation network. Analysis is conducted with Automatic Weather System (AWS) rainfall data, global upper air grid observation (i.e., temperature, pressure, humidity), Himawari satellite data (i.e., water vapor) during 2013-2015 of Korea. This study will provide a guideline to construct observation network for not only improving weather prediction skill but also cost-effectiveness.

Preliminary Design Program: Vapor Compression Distillation Flight Experiment Program

NASA Technical Reports Server (NTRS)

Schubert, F. H.; Boyda, R. B.

1995-01-01

This document provides a description of the results of a program to prepare a preliminary design of a flight experiment to demonstrate the function of a Vapor Compression Distillation (VCD) Wastewater Processor (WWP) in microgravity. This report describes the test sequence to be performed and the hardware, control/monitor instrumentation and software designs prepared to perform the defined tests. the purpose of the flight experiment is to significantly reduce the technical and programmatic risks associated with implementing a VCD-based WWP on board the International Space Station Alpha.

Research on Fracture of Aluminum Foil in Microscale Laser Peen Forming

NASA Astrophysics Data System (ADS)

Zheng, Chao; Sun, Sheng; Liu, Jing; Ji, Zhong

2010-06-01

A novel numerical method for dynamic fracture in microscale laser peen forming (μLPF) of aluminum foils was presented and the role of the die diameter on fracture behavior at the ultra high strain rate was investigated via both experimental and numerical methods. μLPF is a process in which the plastic deformation is generated through laser-induced shock wave and compressive residual stresses can be imparted to improve the fatigue life of micro parts. During μLPF, the pressure exerted on the target is higher than 1 GPa and the strain rate is greater than 106s-1, so the mechanical behavior of materials in this dynamic process is very different from that under static or quasi-static conditions. In the present study, the finite element method with grain and grain boundary elements was used to analyze the μLPF process of aluminum foils with a thickness of 60 μm. The onset and propagation of crack were simulated in this way that the specified nodes were tied together until the equivalent plastic strain exceeded a certain value. Under a given value of plastic strain, the influence of die diameters of 0.6, 1.0, and 1.6 mm on the fracture mode of the material was predicted. A series of experiments were carried out to verify the numerical model. The geometrical morphologies of fracture regions were observed via optical microscope and scan electron microscope. In results from both experiments and simulations, the size of the die diameter affects the location of the fracture: (I) Fracture appeared at the entrance of the die for die diameters of 0.6 and 1.0 mm. (II) Fracture occurred near the centre of the formed dome for 1.6 mm die diameter. The generation mechanism of two fracture modes was explained. This work provides a preliminary insight into the fracture behavior of materials under the ultra high strain rate and lays the ground work for more in-depth simulations in the future study.

Preliminary pioneer 10 encounter results from the ames research center plasma analyzer experiment.

PubMed

Wolfe, J H; Collard, H R; Mihalov, J D; Intriligator, D S

1974-01-25

Preliminary results from the Ames Research Center plasma analyzer experiment for the Pioneer 10 Jupiter encounter indicate that Jupiter has a detached bow shock and magnetopause similar to the case at Earth but much larger in spatial extent. In contrast to Earth, Jupiter's outer magnetosphere appears to be highly inflated by thermal plasma and therefore highly responsive in size to changes in solar wind dynamic pressure.

W(h)ither the Sense of Wonder of Pre-Service Primary Teachers' when Teaching Science?: A Preliminary Study of Their Personal Experiences

ERIC Educational Resources Information Center

Stolberg, Tonie L.

2008-01-01

This preliminary study seeks to explore whether wonder-based reflections are sources of inspiration for our future teachers of science. What experiences have brought them personally a sense of wonder and when, if at all, do they employ scientific explanations of those events? In all 140 pre-service primary teachers, when questioned, described 240…

Physical similarity or numerical representation counts in same-different, numerical comparison, physical comparison, and priming tasks?

PubMed

Zhang, Li; Xin, Ziqiang; Feng, Tingyong; Chen, Yinghe; Szűcs, Denes

2018-03-01

Recent studies have highlighted the fact that some tasks used to study symbolic number representations are confounded by judgments about physical similarity. Here, we investigated whether the contribution of physical similarity and numerical representation differed in the often-used symbolic same-different, numerical comparison, physical comparison, and priming tasks. Experiment 1 showed that subjective physical similarity was the best predictor of participants' performance in the same-different task, regardless of simultaneous or sequential presentation. Furthermore, the contribution of subjective physical similarity was larger in a simultaneous presentation than in a sequential presentation. Experiment 2 showed that only numerical representation was involved in numerical comparison. Experiment 3 showed that both subjective physical similarity and numerical representation contributed to participants' physical comparison performance. Finally, only numerical representation contributed to participants' performance in a priming task as revealed by Experiment 4. Taken together, the contribution of physical similarity and numerical representation depends on task demands. Performance primarily seems to rely on numerical properties in tasks that require explicit quantitative comparison judgments (physical or numerical), while physical stimulus properties exert an effect in the same-different task.

Numerical Mantle Convection Models With a Flexible Thermodynamic Interface

NASA Astrophysics Data System (ADS)

van den Berg, A. P.; Jacobs, M. H.; de Jong, B. H.

2001-12-01

Accurate material properties are needed for deep mantle (P,T) conditions in order to predict the longterm behavior of convection planetary mantles. Also the interpretation of seismological observations concerning the deep mantle in terms of mantle flow models calls for a consistent thermodynamical description of the basic physical parameters. We have interfaced a compressible convection code using the anelastic liquid approach based on finite element methods, to a database containing a full thermodynamic description of mantle silicates (Ita and King, J. Geophys. Res., 99, 15,939-15,940, 1994). The model is based on high resolution (P,T) tables of the relevant thermodynamic properties containing typically 50 million (P,T) table gridpoints to obtain resolution in (P,T) space of 1 K and an equivalent of 1 km. The resulting model is completely flexible such that numerical mantle convection experiments can be performed for any mantle composition for which the thermodynamic database is available. We present results of experiments for 2D cartesian models using a data base for magnesium-iron silicate in a pyrolitic composition (Stixrude and Bukowinski, Geoph.Monogr.Ser., 74, 131-142, 1993) and a recent thermodynamical model for magnesium silicate for the complete mantle (P,T) range, (Jacobs and Oonk, Phys. Chem. Mineral, 269, inpress 2001). Preliminary results of bulksound velocity distribution derived in a consistent way from the convection results and the thermodynamic database show a `realistic' mantle profile with bulkvelocity variations decreasing from several percent in the upper mantle to less than a percent in the deep lower mantle.

Massive stars, disks, and clustered star formation

NASA Astrophysics Data System (ADS)

Moeckel, Nickolas Barry

The formation of an isolated massive star is inherently more complex than the relatively well-understood collapse of an isolated, low-mass star. The dense, clustered environment where massive stars are predominantly found further complicates the picture, and suggests that interactions with other stars may play an important role in the early life of these objects. In this thesis we present the results of numerical hydrodynamic experiments investigating interactions between a massive protostar and its lower-mass cluster siblings. We explore the impact of these interactions on the orientation of disks and outflows, which are potentially observable indications of encounters during the formation of a star. We show that these encounters efficiently form eccentric binary systems, and in clusters similar to Orion they occur frequently enough to contribute to the high multiplicity of massive stars. We suggest that the massive protostar in Cepheus A is currently undergoing a series of interactions, and present simulations tailored to that system. We also apply the numerical techniques used in the massive star investigations to a much lower-mass regime, the formation of planetary systems around Solar- mass stars. We perform a small number of illustrative planet-planet scattering experiments, which have been used to explain the eccentricity distribution of extrasolar planets. We add the complication of a remnant gas disk, and show that this feature has the potential to stabilize the system against strong encounters between planets. We present preliminary simulations of Bondi-Hoyle accretion onto a protoplanetary disk, and consider the impact of the flow on the disk properties as well as the impact of the disk on the accretion flow.

Coupled neutronics and thermal-hydraulics numerical simulations of a Molten Fast Salt Reactor (MFSR)

NASA Astrophysics Data System (ADS)

Laureau, A.; Rubiolo, P. R.; Heuer, D.; Merle-Lucotte, E.; Brovchenko, M.

2014-06-01

Coupled neutronics and thermalhydraulic numerical analyses of a molten salt fast reactor are presented. These preliminary numerical simulations are carried-out using the Monte Carlo code MCNP and the Computation Fluid Dynamic code OpenFOAM. The main objectives of this analysis performed at steady-reactor conditions are to confirm the acceptability of the current neutronic and thermalhydraulic designs of the reactor, to study the effects of the reactor operating conditions on some of the key MSFR design parameters such as the temperature peaking factor. The effects of the precursor's motion on the reactor safety parameters such as the effective fraction of delayed neutrons have been evaluated.

Aeroacoustics of Turbulent High-Speed Jets

NASA Technical Reports Server (NTRS)

Rao, Ram Mohan; Lundgren, Thomas S.

1996-01-01

Aeroacoustic noise generation in a supersonic round jet is studied to understand in particular the effect of turbulence structure on the noise without numerically compromising the turbulence itself. This means that direct numerical simulations (DNS's) are needed. In order to use DNS at high enough Reynolds numbers to get sufficient turbulence structure we have decided to solve the temporal jet problem, using periodicity in the direction of the jet axis. Physically this means that turbulent structures in the jet are repeated in successive downstream cells instead of being gradually modified downstream into a jet plume. Therefore in order to answer some questions about the turbulence we will partially compromise the overall structure of the jet. The first section of chapter 1 describes some work on the linear stability of a supersonic round jet and the implications of this for the jet noise problem. In the second section we present preliminary work done using a TVD numerical scheme on a CM5. This work is only two-dimensional (plane) but shows very interesting results, including weak shock waves. However this is a nonviscous computation and the method resolves the shocks by adding extra numerical dissipation where the gradients are large. One wonders whether the extra dissipation would influence small turbulent structures like small intense vortices. The second chapter is an extensive discussion of preliminary numerical work using the spectral method to solve the compressible Navier-Stokes equations to study turbulent jet flows. The method uses Fourier expansions in the azimuthal and streamwise direction and a 1-D B-spline basis representation in the radial direction. The B-spline basis is locally supported and this ensures block diagonal matrix equations which are solved in O(N) steps. A very accurate highly resolved DNS of a turbulent jet flow is expected.

Apparatus analysis and preliminary design of low gravity porous solids experiment for STS Orbiter mid-deck

NASA Technical Reports Server (NTRS)

Fleeter, R. D.; Kropp, J. L.

1983-01-01

The apparatus analysis laboratory equipment design and fabrication and the preliminary design of the Combustion of Porous Solids Experiment for operation in the mid-deck area of the Shuttle are described. The apparatus analysis indicated that the mid-deck region of the STS was a feasible region of the Shuttle for operation. A sixteen tube concept was developed with tubes of 75 cm length and up to 5.6 cm accommodated. The experiment is viewed by IR sensors and a 16 mm camera. Laboratory equipment was designed and fabricated to test the parible injection, mixing and venting concepts. This equipment was delivered to NASA/LeRC. A preliminary design was made for the experiment based upon the apparatus analysis. The design incorporated results from the Phase ""O'' Safety Review. This design utilizes a closed tube concept in which the particles are stored, injected and burned with no coupling to the Shuttle environment. Drawings of the major components and an assembly are given. The electronics are described for the experiment. An equipment list is presented and an experiment weight estimate is determined. The mission operation requirements are outlined.

An atmospheric dispersion index for prescribed burning

Treesearch

Leonidas G. Lavdas

1986-01-01

A numerical index that estimates the atmosphere's capacity to disperse smoke from prescribed burning is described. The physical assumptions and mathematical development of the index are given in detail. A preliminary interpretation of dispersion index values is offered. A FORTRAN subroutine package for computing the index is included.

Global anti-corporate struggle: a preliminary analysis.

PubMed

Crossley, Nick

2002-12-01

This paper offers a preliminary analysis of the recent wave of anti-corporate protest that has swept across numerous countries throughout the world. In the first part of the paper the social structure of this phenomenon is examined. Specifically, it is argued that it should be understood as a 'field', in Pierre Bourdieu's sense of the term. In the second part of the paper the factors which account for the emergence of this field are explored, using a 'value-added' model which focuses upon the interplay of strains, situational definitions, focal events, opportunities and the circulation of protest relevant resources. The paper is conceived as a preliminary analysis which outlines a framework and draws out important themes. It is not offered as a complete account but rather as a basis from which more specific and focused studies might stem.

Fourier-spectral element approximation of the ion–electron Braginskii system with application to tokamak edge plasma in divertor configuration

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

Minjeaud, Sebastian; INRIA project CASTOR; Pasquetti, Richard, E-mail: richard.pasquetti@unice.fr

Due to the extreme conditions required to produce energy by nuclear fusion in tokamaks, simulating the plasma behavior is an important but challenging task. We focus on the edge part of the plasma, where fluid approaches are probably the best suited, and our approach relies on the Braginskii ion–electron model. Assuming that the electric field is electrostatic, this yields a set of 10 strongly coupled and non-linear conservation equations that exhibit multiscale and anisotropy features. The computational domain is a torus of complex geometrical section, that corresponds to the divertor configuration, i.e. with an “X-point” in the magnetic surfaces. Tomore » capture the complex physics that is involved, high order methods are used: The time-discretization is based on a Strang splitting, that combines implicit and explicit high order Runge–Kutta schemes, and the space discretization makes use of the spectral element method in the poloidal plane together with Fourier expansions in the toroidal direction. The paper thoroughly describes the algorithms that have been developed, provides some numerical validations of the key algorithms and exhibits the results of preliminary numerical experiments. In particular, we point out that the highest frequency of the system is intermediate between the ion and electron cyclotron frequencies.« less

An Experimental Investigation of Flow past a Wing at high Angles of Attack

NASA Astrophysics Data System (ADS)

Dalela, Vipul; Mukherjee, Rinku

2017-11-01

The aerodynamic characteristics for post-stall angles of attack past a single and/or multiple 3D wing(s) have been studied using a novel `decambering technique' assuming the flow to be steady. It is expected that the location of separation as well as the strength of the separated flow is unsteady. The objective of this work therefore is to investigate flow at high angles of attack considering unsteady behavior. The numerical technique used for this purpose that accounts for loss in camber due to flow separation is termed as `decambering'. Two linear functions are used to define the `decambering' for the steady case, located at the leading edge and anywhere between 50%-80% chord. Wind tunnel experiments are to be conducted to study the unsteady nature of separated flow using flow visualization techniques. An estimation of the unsteady wake will be of paramount importance. It is expected to get an experimental corroboration for the numerical decambering. A NACA 4415 wing section is being tested for a range of Reynolds numbers. It is observed from the preliminary results that the drag becomes more dominant after increasing the Reynolds number from Re = 0.093 ×106 to Re = 0.128 ×106 resulting a gentle decrease in the lift coefficient, Cl.

Non-robust numerical simulations of analogue extension experiments

NASA Astrophysics Data System (ADS)

Naliboff, John; Buiter, Susanne

2016-04-01

Numerical and analogue models of lithospheric deformation provide significant insight into the tectonic processes that lead to specific structural and geophysical observations. As these two types of models contain distinct assumptions and tradeoffs, investigations drawing conclusions from both can reveal robust links between first-order processes and observations. Recent studies have focused on detailed comparisons between numerical and analogue experiments in both compressional and extensional tectonics, sometimes involving multiple lithospheric deformation codes and analogue setups. While such comparisons often show good agreement on first-order deformation styles, results frequently diverge on second-order structures, such as shear zone dip angles or spacing, and in certain cases even on first-order structures. Here, we present finite-element experiments that are designed to directly reproduce analogue "sandbox" extension experiments at the cm-scale. We use material properties and boundary conditions that are directly taken from analogue experiments and use a Drucker-Prager failure model to simulate shear zone formation in sand. We find that our numerical experiments are highly sensitive to numerous numerical parameters. For example, changes to the numerical resolution, velocity convergence parameters and elemental viscosity averaging commonly produce significant changes in first- and second-order structures accommodating deformation. The sensitivity of the numerical simulations to small parameter changes likely reflects a number of factors, including, but not limited to, high angles of internal friction assigned to sand, complex, unknown interactions between the brittle sand (used as an upper crust equivalent) and viscous silicone (lower crust), highly non-linear strain weakening processes and poor constraints on the cohesion of sand. Our numerical-analogue comparison is hampered by (a) an incomplete knowledge of the fine details of sand failure and sand properties, and (b) likely limitations to the use of a continuum Drucker-Prager model for representing shear zone formation in sand. In some cases our numerical experiments provide reasonable fits to first-order structures observed in the analogue experiments, but the numerical sensitivity to small parameter variations leads us to conclude that the numerical experiments are not robust.

Application of carbon FRP for fatigue strengthening of old steel structures

NASA Astrophysics Data System (ADS)

Vůjtěch, J.; Ryjáček, P.; Vovesný, M.

2017-02-01

The traffic requirements on the existing infrastructure are rising still. This coupled with its age puts a strain on it. This is especially problematic for old steel bridges. Higher and more frequent loads will lead to development of fatigue damage to those structures. This causes an issue for the infrastructure owners as the existing methods of repair are difficult, time consuming and expensive. So there is a need to find some easier alternatives. One of such can be the use of carbon fibre reinforced polymers (CFRP). They are being successfully used for repairs and strengthening of concrete structures however their use with steel is still relatively new. The purpose of this work is to establish how does a deteriorated steel reinforced with CFRP behave under fatigue loading. To test this a series of experiments was designed. With the help of a preliminary numerical study the dimensions of the specimens and the applied loading was established. There are two sets of specimens. With both we are using mild steel and each set has different level of surface deterioration (corrosion pits or corrosion holes). The specimens are reinforced using hand laid wet layup composites. They are subjected to fatigue loading and the difference between the fatigue life reinforced and unreinforced specimens is observed. Based on the preliminary study, it is expected, that the reinforcement will prolong the life expectancy by half.

Mathematical modelling of risk reduction in reinsurance

NASA Astrophysics Data System (ADS)

Balashov, R. B.; Kryanev, A. V.; Sliva, D. E.

2017-01-01

The paper presents a mathematical model of efficient portfolio formation in the reinsurance markets. The presented approach provides the optimal ratio between the expected value of return and the risk of yield values below a certain level. The uncertainty in the return values is conditioned by use of expert evaluations and preliminary calculations, which result in expected return values and the corresponding risk levels. The proposed method allows for implementation of computationally simple schemes and algorithms for numerical calculation of the numerical structure of the efficient portfolios of reinsurance contracts of a given insurance company.

Numerical aerodynamic simulation facility preliminary study, volume 1

NASA Technical Reports Server (NTRS)

1977-01-01

A technology forecast was established for the 1980-1985 time frame and the appropriateness of various logic and memory technologies for the design of the numerical aerodynamic simulation facility was assessed. Flow models and their characteristics were analyzed and matched against candidate processor architecture. Metrics were established for the total facility, and housing and support requirements of the facility were identified. An overview of the system is presented, with emphasis on the hardware of the Navier-Stokes solver, which is the key element of the system. Software elements of the system are also discussed.

Numerical parametric studies of spray combustion instability

NASA Technical Reports Server (NTRS)

Pindera, M. Z.

1993-01-01

A coupled numerical algorithm has been developed for studies of combustion instabilities in spray-driven liquid rocket engines. The model couples gas and liquid phase physics using the method of fractional steps. Also introduced is a novel, efficient methodology for accounting for spray formation through direct solution of liquid phase equations. Preliminary parametric studies show marked sensitivity of spray penetration and geometry to droplet diameter, considerations of liquid core, and acoustic interactions. Less sensitivity was shown to the combustion model type although more rigorous (multi-step) formulations may be needed for the differences to become apparent.

Solar thermal storage applications program

NASA Astrophysics Data System (ADS)

Peila, W. C.

1982-12-01

The efforts of the Storage Applications Program are reviewed. The program concentrated on the investigation of storage media and evaluation of storage methods. Extensive effort was given to experimental and analytical investigations of nitrate salts. Two tasks are the preliminary design of a 1200 MW/sub th/ system and the design, construction, operation, and evaluation of a subsystem research experiment, which utilized the same design. Some preliminary conclusions drawn from the subsystem research experiment are given.

Preliminary Computational Analysis of the (HIRENASD) Configuration in Preparation for the Aeroelastic Prediction Workshop

NASA Technical Reports Server (NTRS)

Chwalowski, Pawel; Florance, Jennifer P.; Heeg, Jennifer; Wieseman, Carol D.; Perry, Boyd P.

2011-01-01

This paper presents preliminary computational aeroelastic analysis results generated in preparation for the first Aeroelastic Prediction Workshop (AePW). These results were produced using FUN3D software developed at NASA Langley and are compared against the experimental data generated during the HIgh REynolds Number Aero- Structural Dynamics (HIRENASD) Project. The HIRENASD wind-tunnel model was tested in the European Transonic Windtunnel in 2006 by Aachen University0s Department of Mechanics with funding from the German Research Foundation. The computational effort discussed here was performed (1) to obtain a preliminary assessment of the ability of the FUN3D code to accurately compute physical quantities experimentally measured on the HIRENASD model and (2) to translate the lessons learned from the FUN3D analysis of HIRENASD into a set of initial guidelines for the first AePW, which includes test cases for the HIRENASD model and its experimental data set. This paper compares the computational and experimental results obtained at Mach 0.8 for a Reynolds number of 7 million based on chord, corresponding to the HIRENASD test conditions No. 132 and No. 159. Aerodynamic loads and static aeroelastic displacements are compared at two levels of the grid resolution. Harmonic perturbation numerical results are compared with the experimental data using the magnitude and phase relationship between pressure coefficients and displacement. A dynamic aeroelastic numerical calculation is presented at one wind-tunnel condition in the form of the time history of the generalized displacements. Additional FUN3D validation results are also presented for the AGARD 445.6 wing data set. This wing was tested in the Transonic Dynamics Tunnel and is commonly used in the preliminary benchmarking of computational aeroelastic software.

Preliminary Findings from the SHERE ISS Experiment

NASA Technical Reports Server (NTRS)

Hall, Nancy R.; McKinley, Gareth H.; Erni, Philipp; Soulages, Johannes; Magee, Kevin S.

2009-01-01

The Shear History Extensional Rheology Experiment (SHERE) is an International Space Station (ISS) glovebox experiment designed to study the effect of preshear on the transient evolution of the microstructure and viscoelastic tensile stresses for monodisperse dilute polymer solutions. The SHERE experiment hardware was launched on Shuttle Mission STS-120 (ISS Flight 10A) on October 22, 2007, and 20 fluid samples were launched on Shuttle Mission STS-123 (ISS Flight 10/A) on March 11, 2008. Astronaut Gregory Chamitoff performed experiments during Increment 17 on the ISS between June and September 2008. A summary of the ten year history of the hardware development, the experiment's science objectives, and Increment 17's flight operations are discussed in the paper. A brief summary of the preliminary science results is also discussed.

Attempts at a numerical realisation of stochastic differential equations containing Preisach operator

NASA Astrophysics Data System (ADS)

McCarthy, S.; Rachinskii, D.

2011-01-01

We describe two Euler type numerical schemes obtained by discretisation of a stochastic differential equation which contains the Preisach memory operator. Equations of this type are of interest in areas such as macroeconomics and terrestrial hydrology where deterministic models containing the Preisach operator have been developed but do not fully encapsulate stochastic aspects of the area. A simple price dynamics model is presented as one motivating example for our studies. Some numerical evidence is given that the two numerical schemes converge to the same limit as the time step decreases. We show that the Preisach term introduces a damping effect which increases on the parts of the trajectory demonstrating a stronger upwards or downwards trend. The results are preliminary to a broader programme of research of stochastic differential equations with the Preisach hysteresis operator.

Tomographic Reconstruction from a Few Views: A Multi-Marginal Optimal Transport Approach

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

Abraham, I., E-mail: isabelle.abraham@cea.fr; Abraham, R., E-mail: romain.abraham@univ-orleans.fr; Bergounioux, M., E-mail: maitine.bergounioux@univ-orleans.fr

2017-02-15

In this article, we focus on tomographic reconstruction. The problem is to determine the shape of the interior interface using a tomographic approach while very few X-ray radiographs are performed. We use a multi-marginal optimal transport approach. Preliminary numerical results are presented.

Modeling the Change in PSAT Scores: A Growth Modeling Approach

ERIC Educational Resources Information Center

Himelfarb, Igor

2012-01-01

The Preliminary SAT/National Merit Scholarship Qualifying Test (PSAT/NMSQT) is a test jointly administrated by the College Board and National Merit Scholarship Corporation, which is used to prepare high school students for the SAT, and as initial screening for numerous scholarships (Marini, Mattern, & Shaw, 2011). Previous research has…

Using Speed Dating Sessions to Foster Collaboration in Continuing Interdisciplinary Education

ERIC Educational Resources Information Center

Laprise, Rejean; Thivierge, Robert L.

2012-01-01

Introduction: There are numerous examples of care gaps that could be reduced through enhanced knowledge exchange and practice collaboration between medical specialist physicians. In this paper, we report preliminary results on using speed-dating sessions (SDSs) to stimulate the development of continuing interdisciplinary education (CIDE)…

Inventory of Data Sources in Science and Technology. A Preliminary Survey.

ERIC Educational Resources Information Center

International Council of Scientific Unions, Paris (France).

Provided in this inventory are sources of numerical or factual data in selected fields of basic science and applied science/technology. The objective of the inventory is to provide organizations and individuals (scientists, engineers, and information specialists), particularly those in developing countries, with basic data sources relevant to…

Buoyancy Driven Shear Flows of Bubble Suspensions

NASA Technical Reports Server (NTRS)

Koch, D. L.; Hill, R. J.; Chellppannair, T.; Zenit, R.; Zenit, R.; Spelt, P. D. M.

1999-01-01

In this work the gas volume fraction and the root-mean-squared fluid velocity are measured in buoyancy driven shear flows of bubble suspensions in a tall, inclined, rectangular channel. The experiments are performed under conditions where We << 1a nd Re >> 1, for which comparisons are made with kinetic theory and numerical simulations. Here Re = gamma(a(exp 2)/nu is the Reynolds number and We = rho(gamma(exp 2))a(exp 3)/sigma is the Weber number; gamma is the shear rate, a is the bubble radius, nu is the kinematic viscosity of the liquid, rho is the density of the liquid, and sigma is the surface tension of the gas/liquid interface. Kang et al. calculated the bubble phase pressure and velocity variance of sheared bubble suspensions under conditions where the bubbles are spherical and the liquid phase velocity field can be approximated using potential flow theory, i.e. We= 0 and Re >> 1. Such conditions can be achieved in an experiment using gas bubbles, with a radius of O(0.5mm), in water. The theory requires that there be no average relative motion of the gas and liquid phases, hence the motivation for an experimental program in microgravity. The necessity of performing preliminary, Earth based experiments, however, requires performing experiments where the gas phase rises in the liquid, which significantly complicates the comparison of experiments with theory. Rather than comparing experimental results with theory for a uniform, homogeneous shear flow, experiments can be compared directly with solutions of the averaged equations of motion for bubble suspensions. This requires accounting for the significant lift force acting on the gas phase when the bubbles rise parallel to the average velocity of the sheared suspension. Shear flows can be produced in which the bubble phase pressure gradient, arising from shear induced collisions amongst the bubbles, balances a body force (centrifugal or gravitational) on the gas phase. A steady, non-uniform gas volume fraction can be measured, from which the bubble phase pressure gradient can be obtained and compared to theory and numerical simulations. The presence of bounding walls further complicates the experiments, since the detailed interactions of the bubbles with bounding walls is not well understood, especially in the presence of gravity, where the momentum and energy exchange depends on the inclination of the wall.

Process material management in the Space Station environment

NASA Technical Reports Server (NTRS)

Perry, J. L.; Humphries, W. R.

1988-01-01

The Space Station will provide a unique facility for conducting material-processing and life-science experiments under microgravity conditions. These conditions place special requirements on the U.S. Laboratory for storing and transporting chemicals and process fluids, reclaiming water from selected experiments, treating and storing experiment wastes, and providing vacuum utilities. To meet these needs and provide a safe laboratory environment, the Process Material Management System (PMMS) is being developed. Preliminary design requirements and concepts related to the PMMS are addressed, and the MSFC PMMS breadboard test facility and a preliminary plan for validating the overall system design are discussed.

Preliminary investigations of protein crystal growth using the Space Shuttle

NASA Technical Reports Server (NTRS)

Delucas, L. J.; Suddath, F. L.; Snyder, R.; Naumann, R.; Broom, M. B.; Pusey, M.; Yost, V.; Herren, B .; Carter, D.

1986-01-01

Four preliminary Shuttle experiments are described which have been used to develop prototype hardware for a more advanced system that will evaluate effects of gravity on protein crystal growth. The first phase of these experiments has centered on the development of micromethods for protein crystal growth by vapor-diffusion techniques (using a space version of the hanging-drop method) and on dialysis using microdialysis cells. Results suggest that the elimination of density-driven sedimentation can effect crystal morphology. In the dialysis experiment, space-grown crystals of concanavalin B were three times longer and 1/3 the thickness of earth-grown crystals.

Fiscal year 1981 US corn and soybeans pilot preliminary experiment plan, phase 1

NASA Technical Reports Server (NTRS)

Livingston, G. P.; Nedelman, K. S.; Norwood, D. F.; Smith, J. H. (Principal Investigator)

1981-01-01

A draft of the preliminary experiment plan for the foreign commodity production forecasting project fiscal year 1981 is presented. This draft plan includes: definition of the phase 1 and 2 U.S. pilot objectives; the proposed experiment design to evaluate crop calendar, area estimation, and area aggregation components for corn and soybean technologies using 1978/1979 crop-year data; a description of individual sensitivity evaluations of the baseline corn and soybean segment classification procedure; and technology and data assessment in support of the corn and soybean estimation technology for use in the U.S. central corn belt.

Preliminary technical results review of FY81 experiments. Volume 1: Fiscal year 1981/82 spring small grains pilot experiment. [Canada and the United States

NASA Technical Reports Server (NTRS)

1981-01-01

Technical progress made in the foreign commodity production forecasting for the advancement of spring small grains (SSG) area estimation is reported with emphasis on results achieved since the last AgRISTARS level semiannual review. Major objectives and accomplishments are reviewed and the experiment is described. The technical approach data assessment, and data systems used are considered. Results of the group approach comparison study are presented along with preliminary aggregation results for SSG processing procedures. The outlook for the future is assessed.

An Open-Structure Treadmill Gait Trainer: From Research to Application.

PubMed

Li, Jian; Chen, Diansheng; Fan, Yubo

2017-01-01

Lower limb rehabilitation robots are designed to enhance gait function in individuals with motor impairments. Although numerous rehabilitation robots have been developed, only few of these robots have been used in practical health care, particularly in China. The objective of this study is to construct a lower limb rehabilitation robot and bridge the gap between research and application. Open structure to facilitate practical application was created for the whole robot. Three typical movement patterns of a single leg were adopted in designing the exoskeletons, and force models for patient training were established and analyzed under three different conditions, respectively, and then a control system and security strategy were introduced. After establishing the robot, a preliminary experiment on the actual use of a prototype by patients was conducted to validate the functionality of the robot. The experiment showed that different patients and stages displayed different performances, and results on the trend variations across patients and across stages confirmed the validity of the robot and suggested that the design may lead to a system that could be successful in the treatment of patients with walking disorders in China. Furthermore, this study could provide a reference for a similar application design.

Some bifurcation routes to chaos of thermocapillary convection in two-dimensional liquid layers of finite extent

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

Li, K., E-mail: likai@imech.ac.cn; University of Chinese Academy of Sciences, Beijing 100190; Xun, B.

2016-05-15

As a part of the preliminary studies for the future space experiment (Zona-K) in the Russian module of the International Space Station, some bifurcation routes to chaos of thermocapillary convection in two-dimensional liquid layers filled with 10 cSt silicone oil have been numerically studied in this paper. As the laterally applied temperature difference is raised, variations in the spatial structure and temporal evolution of the thermocapillary convection and a complex sequence of transitions are observed. The results show that the finite extent of the liquid layer significantly influences the tempo-spatial evolution of the thermocapillary convection. Moreover, the bifurcation route ofmore » the thermocapillary convection changes very sensitively by the aspect ratio of the liquid layer. With the increasing Reynolds number (applied temperature difference), the steady thermocapillary convection experiences two consecutive transitions from periodic oscillatory state to quasi-periodic oscillatory state with frequency-locking before emergence of chaotic convection in a liquid layer of aspect ratio 14.25, and the thermocapillary convection undergoes period-doubling cascades leading to chaotic convection in a liquid layer of aspect ratio 13.0.« less

Development of regional liquefaction-induced deformation hazard maps

USGS Publications Warehouse

Rosinski, A.; Knudsen, K.-L.; Wu, J.; Seed, R.B.; Real, C.R.; ,

2004-01-01

This paper describes part of a project to assess the feasibility of producing regional (1:24,000-scale) liquefaction hazard maps that are based-on potential liquefaction-induced deformation. The study area is the central Santa Clara Valley, at the south end of San Francisco Bay in Central California. The information collected and used includes: a) detailed Quaternary geological mapping, b) over 650 geotechnical borings, c) probabilistic earthquake shaking information, and d) ground-water levels. Predictions of strain can be made using either empirical formulations or numerical simulations. In this project lateral spread displacements are estimated and new empirical relations to estimate future volumetric and shear strain are used. Geotechnical boring data to are used to: (a) develop isopach maps showing the thickness of sediment thatis likely to liquefy and deform under earthquake shaking; and (b) assess the variability in engineering properties within and between geologic map units. Preliminary results reveal that late Holocene deposits are likely to experience the greatest liquefaction-induced strains, while Holocene and late Pleistocene deposits are likely to experience significantly less horizontal and vertical strain in future earthquakes. Development of maps based on these analyses is feasible.

Observational Definition of Future AGN Echo-Mapping Experiments

NASA Technical Reports Server (NTRS)

Collier, Stefan; Peterson, Bradley M.; Horne, Keith

2001-01-01

We describe numerical simulations we have begun in order to determine the observational requirements for future echo-apping experiments. We focus on two particular problems: (1) determination of the structure and kinematics of the broad-line region through emission- line reverberation mapping, and (2) detection of interband continuum lags that may be used as a probe of the continuum source, presumably a temperature-stratified accretion disk. Our preliminary results suggest the broad-line region can be reverberation-mapped to good precision with spectra of signal-to-noise ratio per pixel S/N approx. = 30, time resolution (Delta)t approx. = 0.1 day, and duration of about 60 days (which is a factor of three larger than the longest time scale in the input models); data that meet these requirements do not yet exist. We also find that interband continuum lags of approx. greater than 0.5 days can be detected at approx. greater than 95% confidence with at least daily observations for about 6 weeks, or rather more easily and definitively with shorter programs undertaken with satellite-based observatories. The results of these simulations show that significant steps forward in multiwavelength monitoring will almost certainly require dedicated facilities.

Numerical Modelling of Rayleigh Wave Propagation in Course of Rapid Impulse Compaction

NASA Astrophysics Data System (ADS)

Herbut, Aneta; Rybak, Jarosław

2017-10-01

As the soil improvement technologies are the area of a rapid development, they require designing and implementing novel methods of control and calibration in order to ensure the safety of geotechnical works. At Wroclaw University of Science and Technology (Poland), these new methods are continually developed with the aim to provide the appropriate tools for the preliminary design of work process, as well as for the further ongoing on-site control of geotechnical works (steel sheet piling, pile driving or soil improvement technologies). The studies include preliminary numerical simulations and field tests concerning measurements and continuous histogram recording of shocks and vibrations and its ground-born dynamic impact on engineering structures. The impact of vibrations on reinforced concrete and masonry structures in the close proximity of the construction site may be destroying in both architectural and structural meaning. Those limits are juxtaposed in codes of practice, but always need an individual judgment. The results and observations make it possible to delineate specific modifications to the parameters of technology applied (e.g. hammer drop height). On the basis of numerous case studies of practical applications, already summarized and published, we were able to formulate the guidelines for work on the aforementioned sites. This work presents specific aspects of the active design (calibration of building site numerical model) by means of technology calibration, using the investigation of the impact of vibrations that occur during the Impulse Compaction on adjacent structures. A case study entails the impact of construction works on Rayleigh wave propagation in the zone of 100 m (radius) around the Compactor.

A preliminary design of the collinear dielectric wakefield accelerator

NASA Astrophysics Data System (ADS)

Zholents, A.; Gai, W.; Doran, S.; Lindberg, R.; Power, J. G.; Strelnikov, N.; Sun, Y.; Trakhtenberg, E.; Vasserman, I.; Jing, C.; Kanareykin, A.; Li, Y.; Gao, Q.; Shchegolkov, D. Y.; Simakov, E. I.

2016-09-01

A preliminary design of the multi-meter long collinear dielectric wakefield accelerator that achieves a highly efficient transfer of the drive bunch energy to the wakefields and to the witness bunch is considered. It is made from 0.5 m long accelerator modules containing a vacuum chamber with dielectric-lined walls, a quadrupole wiggler, an rf coupler, and BPM assembly. The single bunch breakup instability is a major limiting factor for accelerator efficiency, and the BNS damping is applied to obtain the stable multi-meter long propagation of a drive bunch. Numerical simulations using a 6D particle tracking computer code are performed and tolerances to various errors are defined.

Verification of EPA's " Preliminary remediation goals for radionuclides" (PRG) electronic calculator

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

Stagich, B. H.

The U.S. Environmental Protection Agency (EPA) requested an external, independent verification study of their “Preliminary Remediation Goals for Radionuclides” (PRG) electronic calculator. The calculator provides information on establishing PRGs for radionuclides at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites with radioactive contamination (Verification Study Charge, Background). These risk-based PRGs set concentration limits using carcinogenic toxicity values under specific exposure conditions (PRG User’s Guide, Section 1). The purpose of this verification study is to ascertain that the computer codes has no inherit numerical problems with obtaining solutions as well as to ensure that the equations are programmed correctly.

Intelligent Physiologic Modeling: An Application of Knowledge Based Systems Technology to Medical Education

PubMed Central

Kunstaetter, Robert

1986-01-01

This presentation describes the design and implementation of a knowledge based physiologic modeling system (KBPMS) and a preliminary evaluation of its use as a learning resource within the context of an experimental medical curriculum -- the Harvard New Pathway. KBPMS possesses combined numeric and qualitative simulation capabilities and can provide explanations of its knowledge and behaviour. It has been implemented on a microcomputer with a user interface incorporating interactive graphics. The preliminary evaluation of KBPMS is based on anecdotal data which suggests that the system might have pedagogic potential. Much work remains to be done in enhancing and further evaluating KBPMS.

Preliminary concepts for a solar electric orbit raising experiment

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

Cohen, R.B.; Penn, J.P.; Janson, S.W.

1989-01-01

Some preliminary concepts for a solar electric orbit raising demonstration that will show technological readiness for the development of operational Electric Orbital Transfer Vehicles (EOTVs) are outlined. These ideas could serve as a template for the proposed Electric Insertion Transfer Experiment (ELITE). At this moment, ELITE is not a funded program. Concepts are presented for a solar electric orbit raising demonstration, for ELITE, and for the path from the proposed ELITE to a future operational EOTV. A brief discussion of the benefits to be derived from the use of EOTVs, the conceptual organization of the ELITE team, the key technologiesmore » for EOTV and ELITE, and some preliminary options for the orbit raising vehicle and representative missions are provided.« less

LDEF Experiment P0006 Linear Energy Transfer Spectrum Measurement (LETSME) quick look report

NASA Technical Reports Server (NTRS)

1990-01-01

A preliminary analysis of the various passive radiation detector materials included in the P0006 LETSME experiment flown on LDEF (Long Duration Exposure Facility) is presented. It consists of four tasks: (1) readout and analysis of thermoluminescent detectors (TLD); (2) readout and analysis of fission foil/mica detectors; (3) readout and analysis of (6)LiF/CR-39 detectors; and (4) preliminary processing and readout of CR-39 and polycarbonate plastic nuclear track detectors (PNTD).

Groundstory vegetation response to different thinning intensities in a minor stream bottom in Mississippi: a preliminary analysis

Treesearch

Brent R. Frey; Ellen M. Boerger

2015-01-01

Groundstory vegetation typically accounts for the greatest proportion of plant diversity in temperate forests, representing a critical structural component and mediating numerous ecosystem processes, including tree regeneration. The effects of thinning on groundstory vegetation have received limited study in bottomland hardwood stands. This study investigated...

Evaluation of several types of curing and protective materials for concrete : final report on part I : laboratory and outdoor exposure studies preliminary to field trials.

DOT National Transportation Integrated Search

1970-01-01

Concern for improving the durability of concrete has focused renewed attention on all aspects of concrete technology. Numerous proprietary products which are claimed to improve durability have been marketed as protective coatings, curing agents or co...

A Preliminary Investigation of Stimulus Control Training for Worry: Effects on Anxiety and Insomnia

ERIC Educational Resources Information Center

McGowan, Sarah Kate; Behar, Evelyn

2013-01-01

For individuals with generalized anxiety disorder, worry becomes associated with numerous aspects of life (e.g., time of day, specific stimuli, environmental cues) and is thus under poor discriminative stimulus control (SC). In addition, excessive worry is associated with anxiety, depressed mood, and sleep difficulties. This investigation sought…

Engaging College Science Students and Changing Academic Achievement with Technology: A Quasi-Experimental Preliminary Investigation

ERIC Educational Resources Information Center

Carle, Adam C.; Jaffee, David; Miller, Deborah

2009-01-01

Can modern, computer-based technology engage college students and improve their academic achievement in college? Although numerous examples detail technology's classroom uses, few studies empirically examine whether technologically oriented pedagogical changes factually lead to positive outcomes among college students. In this pilot study, we used…

A nested numerical tidal model of the southern New England bight

NASA Technical Reports Server (NTRS)

Gordon, R. B.; Spaulding, M. L.

1979-01-01

Efforts were focused on the development and application of a three-dimensional numerical model for predicting pollutant and sediment transport in estuarine and coastal environments. To successfully apply the pollutant and sediment transport model to Rhode Island coastal waters, it was determined that the flow field in this region had to be better described through the use of existing numerical circulation models. A nested, barotropic numerical tidal model was applied to the southern New England Bight (Long Island, Block Island, Rhode Island Sounds, Buzzards Bay, and the shelf south of Block Island). Forward time and centered spatial differences were employed with the bottom friction term evaluated at both time levels. Using existing tide records on the New England shelf, adequate information was available to specify the tide height boundary condition further out on the shelf. Preliminary results are within the accuracy of the National Ocean Survey tide table data.

Sanford Underground Research Facility - The United State's Deep Underground Research Facility

NASA Astrophysics Data System (ADS)

Vardiman, D.

2012-12-01

The 2.5 km deep Sanford Underground Research Facility (SURF) is managed by the South Dakota Science and Technology Authority (SDSTA) at the former Homestake Mine site in Lead, South Dakota. The US Department of Energy currently supports the development of the facility using a phased approach for underground deployment of experiments as they obtain an advanced design stage. The geology of the Sanford Laboratory site has been studied during the 125 years of operations at the Homestake Mine and more recently as part of the preliminary geotechnical site investigations for the NSF's Deep Underground Science and Engineering Laboratory project. The overall geology at DUSEL is a well-defined stratigraphic sequence of schist and phyllites. The three major Proterozoic units encountered in the underground consist of interbedded schist, metasediments, and amphibolite schist which are crosscut by Tertiary rhyolite dikes. Preliminary geotechnical site investigations included drift mapping, borehole drilling, borehole televiewing, in-situ stress analysis, laboratory analysis of core, mapping and laser scanning of new excavations, modeling and analysis of all geotechnical information. The investigation was focused upon the determination if the proposed site rock mass could support the world's largest (66 meter diameter) deep underground excavation. While the DUSEL project has subsequently been significantly modified, these data are still available to provide a baseline of the ground conditions which may be judiciously extrapolated throughout the entire Proterozoic rock assemblage for future excavations. Recommendations for facility instrumentation and monitoring were included in the preliminary design of the DUSEL project design and include; single and multiple point extensometers, tape extensometers and convergence measurements (pins), load cells and pressure cells, smart cables, inclinometers/Tiltmeters, Piezometers, thermistors, seismographs and accelerometers, scanners (laser/LIDAR), surveying instruments, and surveying benchmarks and optical survey points. Currently an array of single and multipoint extensometers monitors the Davis Campus. A facility-wide micro seismic monitoring system is anticipated to be deployed during the latter half of 2012. This system is designed to monitor minor events initiated within the historical mined out portions of the facility. The major science programs for the coming five years consist of the MAJORANA DEMONSTRATOR (MJD) neutrinoless double beta decay experiment; the Large Underground Xenon (LUX) dark matter search, the Center for Ultralow Background Experiments at DUSEL (CUBED), numerous geoscience installations, Long-Baseline Neutrino Experiment (LBNE), a nuclear astrophysics program involving a low energy underground particle accelerator, second and third generation dark matter experiments, and additional low background counting facilities. The Sanford Lab facility is an active, U.S. based, deep underground research facility dedicated to science, affording the science community the opportunity to conduct unprecedented scientific research in a broad range of physics, biology and geoscience fields at depth. SURF is actively interested in hosting additional research collaborations and provides resources for full facility design, cost estimation, excavation, construction and support management services.

Novel Shapes of Miscible Interfaces Observed

NASA Technical Reports Server (NTRS)

Balasubramaniam, Ramaswamy; Rashidnia, Nasser

2001-01-01

The dynamics of miscible displacements in a cylindrical tube are being investigated experimentally and numerically, with a view to understand the complex processes that occur, for example, in enhanced oil recovery, hydrology, and filtration. We have observed complex shapes of the interface between two liquids that mix with each other when the less viscous liquid is displaced by the more viscous one in a tube. A less viscous fluid that displaces a more viscous fluid is known to propagate in the form of a "finger," and a flight experiment proposed by Maxworthy et al. to investigate the miscible-interface dynamics is currently being developed by NASA. From the current theory of miscible displacements, which was developed for a porous medium satisfying Darcy's law, it can be shown that in the absence of gravity the interface between the fluids is destabilized and thus susceptible to fingering only when a more viscous fluid is displaced by a less viscous one. Therefore, if the interface is initially flat and the more viscous fluid displaces the less viscous fluid, the interface ought to be stable and remain flat. However, numerical simulations by Chen and Meiburg for such displacement in a cylindrical tube show that the interface is unstable and a finger of the more viscous fluid is indeed formed. Preliminary experiments performed at the NASA Glenn Research Center show that not only can fingering occur when the more viscous fluid displaces a less viscous one in a cylindrical tube, but also that under certain conditions the advancing finger achieves a sinuous or snakelike shape. These experiments were performed using silicone oils in a vertical pipette of small diameter. In the initial configuration, the more viscous fluid rested on top of the less viscous one, and the interface was nominally flat. A dye was added to the upper liquid for ease of observation of the interface between the fluids. The flow was initiated by draining the lower fluid from the bottom of the pipette, at speeds less than 0.1 mm/sec.

A preliminary experiment definition for video landmark acquisition and tracking

NASA Technical Reports Server (NTRS)

Schappell, R. T.; Tietz, J. C.; Hulstrom, R. L.; Cunningham, R. A.; Reel, G. M.

1976-01-01

Six scientific objectives/experiments were derived which consisted of agriculture/forestry/range resources, land use, geology/mineral resources, water resources, marine resources and environmental surveys. Computer calculations were then made of the spectral radiance signature of each of 25 candidate targets as seen by a satellite sensor system. An imaging system capable of recognizing, acquiring and tracking specific generic type surface features was defined. A preliminary experiment definition and design of a video Landmark Acquisition and Tracking system is given. This device will search a 10-mile swath while orbiting the earth, looking for land/water interfaces such as coastlines and rivers.

Guidelines for Computing Longitudinal Dynamic Stability Characteristics of a Subsonic Transport

NASA Technical Reports Server (NTRS)

Thompson, Joseph R.; Frank, Neal T.; Murphy, Patrick C.

2010-01-01

A systematic study is presented to guide the selection of a numerical solution strategy for URANS computation of a subsonic transport configuration undergoing simulated forced oscillation about its pitch axis. Forced oscillation is central to the prevalent wind tunnel methodology for quantifying aircraft dynamic stability derivatives from force and moment coefficients, which is the ultimate goal for the computational simulations. Extensive computations are performed that lead in key insights of the critical numerical parameters affecting solution convergence. A preliminary linear harmonic analysis is included to demonstrate the potential of extracting dynamic stability derivatives from computational solutions.

The stability issues in problems of mathematical modeling

NASA Astrophysics Data System (ADS)

Mokin, A. Yu.; Savenkova, N. P.; Udovichenko, N. S.

2018-03-01

In the paper it is briefly considered various aspects of stability concepts, which are used in physics, mathematics and numerical methods of solution. The interrelation between these concepts is described, the questions of preliminary stability research before the numerical solution of the problem and the correctness of the mathematical statement of the physical problem are discussed. Examples of concrete mathematical statements of individual physical problems are given: a nonlocal problem for the heat equation, the Korteweg-de Fries equation with boundary conditions at infinity, the sine-Gordon equation, the problem of propagation of femtosecond light pulses in an area with a cubic nonlinearity.

Assessing Australian Rainfall Projections in Two Model Resolutions

NASA Astrophysics Data System (ADS)

Taschetto, A.; Haarsma, R. D.; Sen Gupta, A.

2016-02-01

Australian climate is projected to change with increases in greenhouse gases. The IPCC reports an increase in extreme daily rainfall across the country. At the same time, mean rainfall over southeast Australia is projected to reduce during austral winter, but to increase during austral summer, mainly associated with changes in the surrounding oceans. Climate models agree better on the future reduction of average rainfall over the southern regions of Australia compared to the increase in extreme rainfall events. One of the reasons for this disagreement may be related to climate model limitations in simulating the observed mechanisms associated with the mid-latitude weather systems, in particular due to coarse model resolutions. In this study we investigate how changes in sea surface temperature (SST) affect Australian mean and extreme rainfall under global warming, using a suite of numerical experiments at two model resolutions: about 126km (T159) and 25km (T799). The numerical experiments are performed with the earth system model EC-EARTH. Two 6-member ensembles are produced for the present day conditions and a future scenario. The present day ensemble is forced with the observed daily SST from the NOAA National Climatic Data Center from 2002 to 2006. The future scenario simulation is integrated from 2094 to 2098 using the present day SST field added onto the future SST change created from a 17-member ensemble based on the RCP4.5 scenario. Preliminary results show an increase in extreme rainfall events over Tasmania associated with enhanced convection driven by the Tasman Sea warming. We will further discuss how the projected changes in SST will impact the southern mid-latitude weather systems that ultimately affect Australian rainfall.

Large-eddy simulations of mechanical and thermal processes within boundary layer of the Graciosa Island

NASA Astrophysics Data System (ADS)

Sever, G.; Collis, S. M.; Ghate, V. P.

2017-12-01

Three-dimensional numerical experiments are performed to explore the mechanical and thermal impacts of Graciosa Island on the sampling of oceanic airflow and cloud evolution. Ideal and real configurations of flow and terrain are planned using high-resolution, large-eddy resolving (e.g., Δ < 100 meter) simulations. Ideal configurations include model initializations with ideal dry and moist temperature and wind profiles to capture flow features over an island-like topography. Real configurations will use observations from different climatological background states over the Eastern Northern Atlantic, Atmospheric Radiation Measurement (ENA-ARM) site on Graciosa Island. Initial small-domain large-eddy simulations (LES) of dry airflow produce cold-pool formation upstream of an ideal two-kilometer island, with von Kármán like vortices propagation downstream. Although the peak height of Graciosa is less than half kilometer, the Azores island chain has a mountain over 2 km, which may be leading to more complex flow patterns when simulations are extended to a larger domain. Preliminary idealized low-resolution moist simulations indicate that the cloud field is impacted due to the presence of the island. Longer simulations that are performed to capture diurnal evolution of island boundary layer show distinct land/sea breeze formations under quiescent flow conditions. Further numerical experiments are planned to extend moist simulations to include realistic atmospheric profiles and observations of surface fluxes coupled with radiative effects. This work is intended to produce a useful simulation framework coupled with instruments to guide airborne and ground sampling strategies during the ACE-ENA field campaign which is aimed to better characterize marine boundary layer clouds.

A Hybrid Numerical Method for Turbulent Mixing Layers. Degree awarded by Case Western Reserve Univ.

NASA Technical Reports Server (NTRS)

Georgiadis, Nicholas J.

2001-01-01

A hybrid method has been developed for simulations of compressible turbulent mixing layers. Such mixing layers dominate the flows in exhaust systems of modern day aircraft and also those of hypersonic vehicles currently under development. The method configurations in which a dominant structural feature provides an unsteady mechanism to drive the turbulent development in the mixing layer. The hybrid method uses a Reynolds-averaged Navier-Stokes (RANS) procedure to calculate wall bounded regions entering a mixing section, and a Large Eddy Simulation (LES) procedure to calculate the mixing dominated regions. A numerical technique was developed to enable the use of the hybrid RANS-LES method on stretched, non-Cartesian grids. Closure for the RANS equations was obtained using the Cebeci-Smith algebraic turbulence model in conjunction with the wall-function approach of Ota and Goldberg. The wall-function approach enabled a continuous computational grid from the RANS regions to the LES region. The LES equations were closed using the Smagorinsky subgrid scale model. The hybrid RANS-LES method is applied to a benchmark compressible mixing layer experiment. Preliminary two dimensional calculations are used to investigate the effects of axial grid density and boundary conditions. Vortex shedding from the base region of a splitter plate separating the upstream flows was observed to eventually transition to turbulence. The location of the transition, however, was much further downstream than indicated by experiments. Actual LES calculations, performed in three spatial directions, also indicated vortex shedding, but the transition to turbulence was found to occur much closer to the beginning of the mixing section. which is in agreement with experimental observations. These calculations demonstrated that LES simulations must be performed in three dimensions. Comparisons of time-averaged axial velocities and turbulence intensities indicated reasonable agreement with experimental data.

Study of atmospheric parameters measurements using MM-wave radar in synergy with LITE-2

NASA Technical Reports Server (NTRS)

Andrawis, Madeleine Y.

1994-01-01

The Lidar In-Space Technology Experiment, (LITE), has been developed, designed, and built by NASA Langley Research Center, to be flown on the space shuttle 'Discovery' on September 9, 1994. Lidar, which stands for light detecting and ranging, is a radar system that uses short pulses of laser light instead of radio waves in the case of the common radar. This space-based lidar offers atmospheric measurements of stratospheric and tropospheric aerosols, the planetary boundary layer, cloud top heights, and atmospheric temperature and density in the 10-40 km altitude range. A study is being done on the use, advantages, and limitations of a millimeterwave radar to be utilized in synergy with the Lidar system, for the LITE-2 experiment to be flown on a future space shuttle mission. The lower atmospheric attenuation, compared to infrared and optical frequencies, permits the millimeter-wave signals to penetrate through the clouds and measure multi-layered clouds, cloud thickness, and cloud-base height. These measurements would provide a useful input to radiation computations used in the operational numerical weather prediction models, and for forecasting. High power levels, optimum modulation, data processing, and high antenna gain are used to increase the operating range, while space environment, radar tradeoffs, and power availability are considered. Preliminary, numerical calculations are made, using the specifications of an experimental system constructed at Georgia Tech. The noncoherent 94 GHz millimeter-wave radar system has a pulsed output with peak value of 1 kW. The backscatter cross section of the particles to be measured, that are present in the volume covered by the beam footprint, is also studied.

Fetoscopic single-layer repair of open spina bifida using a cellulose patch: preliminary clinical experience.

PubMed

Pedreira, Denise A L; Zanon, Nelci; de Sá, Renato A M; Acacio, Gregório L; Ogeda, Edilson; Belem, Teresa M L O U; Chmait, Ramen H; Kontopoulos, Eftichia; Quintero, Ruben A

2014-11-01

To report our preliminary clinical experience in the antenatal correction of open spina bifida (OSB) using a fetoscopic approach and a simplified closure technique. Four fetuses with lumbar-sacral defects were operated in utero from 25 to 27 weeks. Surgeries were performed percutaneously under general anesthesia using three trocars and partial carbon dioxide insufflation. After dissection of the neural placode, the surrounding skin was closed over a cellulose patch using a single continuous stitch. Surgical closure was successful in three of the four cases. All successful cases showed improvement of the hindbrain herniation and no neonatal neurosurgical repair was required in two cases. Delivery occurred between 31 and 33 weeks, and no fetal or neonatal deaths occurred. Ventriculoperitoneal shunting was not needed in two out of the 3 successful cases. Our preliminary experience suggests that definitive fetoscopic repair of OSB is feasible using our innovative surgical technique. A phase I trial for the fetoscopic correction of OSB with this technique is currently being conducted.

Theoretical study of refraction effects on noise produced by turbulent jets

NASA Technical Reports Server (NTRS)

Graham, E. W.; Graham, B. B.

1975-01-01

The transmission of acoustic disturbances from the interior of a jet into the ambient air is studied. The jet is assumed infinitely long with mean velocity profile independent of streamwise location. The noise generator is a sequence of transient sources drifting with the local fluid and confined to a short length of the jet. In Part 1, supersonic jets are considered. Numerical results for mean-square pressure versus angle in the far-field show unexpected peaks which are very sharp. Analysis of simplified models indicates that these are complex quasi-resonant effects which appear to the stationary observer in a high frequency range. The peaks are real for the idealized model, but would be smoothed by mathematical integration over source position, velocity, and frequency. Subsonic jets were considered in part 2, and a preliminary study of the near-field was attempted. Mean-square radial displacements (or mean radial energy flow or space-time correlations of radial pressure gradient) are first found for very simple cases. The most difficult case studied is a sequence of transient sources at the center of a uniform-velocity circular cylindrical jet. Here a numerical triple integration is required and seems feasible although only preliminary results for mean square radial displacement are now available. These preliminary results show disturbances decreasing with increasing radial distance, and with increasing distance upstream and downstream from the source. A trend towards greater downstream disturbances appears even in the near field.

Scanning Raman Lidar Measurements During the WVIOP2000 and AFWEX Field Experiments

NASA Technical Reports Server (NTRS)

Whiteman, David N.; Evans, K. D.; Berkoff, T. B.; Demoz, B. D.; DiGirolamo, P.; Smith, David E. (Technical Monitor)

2001-01-01

The NASA/Goddard Space Flight Center Scanning Raman Lidar (SRL) participated in the Water Vapor IOP 2000 (WVIOP2000) and ARM FIRE Water Vapor Experiment (AFWEX) at the DOE SGP CART site in northern Oklahoma. These experiments occurred during the period of September and December, 2000. The goals of both the WVIOP2000 and AFWEX were to better characterize the water vapor measurement capability of numerous sensors in the lower atmosphere and upper troposphere, respectively. The SRL received several hardware upgrades in anticipation of these experiments that permitted improved measurements of water vapor during the daytime and in the upper troposphere (UT). The daytime SRL water vapor error statistics were demonstrated a factor of 2-3 improvement compared to the permanently stationed CART Raman lidar (CARL). The performance of the SRL in the UT showed improvements as well. The technological upgrades that permitted these improved SRL measurements could also be implemented in the CARL system. Data examples demonstrating the new daytime and upper tropospheric measurement capability of the SRL will be shown at the meeting. In addition, preliminary analysis will be presented on several topics: 1) inter comparison of the water vapor measurements for several water vapor sensors including SRL, CARL, the NASA/Langley Lidar Atmospheric Sensing Experiment (LASE) flown onboard the NASA DC-8, in-situ sensors flown on the DC-8, and the Max Planck Institute Differential Absorption Lidar 2) comparison of cirrus cloud measurements using SRL and CARL and 3) case studies of meteorological events that occurred during the IOPs such as a cold frontal passage on the night of September 23.

Multidisciplinary Observations of Subduction (MOOS) Experiment in South-Central Alaska

NASA Astrophysics Data System (ADS)

Christensen, D.; Abers, G.; Freymueller, J.

2008-12-01

Seismic and geodetic data are being collected in the Kenai Peninsula and surrounding area of south central Alaska as part of the PASSCAL experiment MOOS. A total of 34 broadband seismic stations were deployed between the summers of 2007 and 2008. Seventeen of these stations continue to operate for an additional year and are scheduled to be removed in the summer of 2009. Numerous GPS campaign sites have and will be visited during the same time period. The MOOS seismic deployment provides coverage across the interplate coupled zone and adjacent transition zone in the shallow parts of the Alaskan subduction zone. It is a southern extension of an earlier broadband deployment BEAAR (Broadband Experiment Across the Alaska Range) to the north. When integrated with the previous BEAAR experiment, these data will allow high-resolution broadband imaging along a 600 km long transect over the Alaska subduction zone, at 10-15 km station spacing. The MOOS deployment allows us to test several hypotheses relating to the postulated subduction of the Yakutat Block and the nature of the coupled zone which ruptured in the great 1964 earthquake. The seismic and geodetic stations cover an area that includes part of the 1964 main asperity and the adjacent, less coupled, region to the southwest. Data gathered from this experiment will shed light on the nature of this boundary from both a geodetic and seismic (or earth structure) perspective. Shallow seismicity recorded by this network greatly improves the catalog of events in this area and helps to delineate active features in the subduction complex. Preliminary results from this project will be presented.

Evaluation and Preliminary Results of the New USNO PPS Timing Receiver

DTIC Science & Technology

2000-11-01

timing receiver, one may currently obtain raw pseudorange and carrier-phase data by periodically downloading such data from a flashcard . Several...preliminary experiments have been performed using data collected from the prototype TTR- 12 receivers’ flashcards and geodetic GPS carrier-phase techniques

The Clinical/Practicum Experience in Professional Preparation: Preliminary Findings

ERIC Educational Resources Information Center

Ralph, Edwin George; Walker, Keith; Wimmer, Randy

2008-01-01

The authors synthesize preliminary findings from an interdisciplinary study of the practicum/clinical phase of undergraduate pre-service education in the professions. Early data analysis identified similarities and differences across disciplines in terms of: (a) the terminology describing each practicum program, (b) the programs' key…

The Numerical Studies Program for the Atmospheric General Circulation Experiment (AGCE) for Spacelab Flights

NASA Technical Reports Server (NTRS)

Fowlis, W. W. (Editor); Davis, M. H. (Editor)

1981-01-01

The atmospheric general circulation experiment (AGCE) numerical design for Spacelab flights was studied. A spherical baroclinic flow experiment which models the large scale circulations of the Earth's atmosphere was proposed. Gravity is simulated by a radial dielectric body force. The major objective of the AGCE is to study nonlinear baroclinic wave flows in spherical geometry. Numerical models must be developed which accurately predict the basic axisymmetric states and the stability of nonlinear baroclinic wave flows. A three dimensional, fully nonlinear, numerical model and the AGCE based on the complete set of equations is required. Progress in the AGCE numerical design studies program is reported.

SmallWorld Behavior of the Worldwide Active Volcanoes Network: Preliminary Results

NASA Astrophysics Data System (ADS)

Spata, A.; Bonforte, A.; Nunnari, G.; Puglisi, G.

2009-12-01

We propose a preliminary complex networks based approach in order to model and characterize volcanoes activity correlation observed on a planetary scale over the last two thousand years. Worldwide volcanic activity is in fact related to the general plate tectonics that locally drives the faults activity, that in turn controls the magma upraise beneath the volcanoes. To find correlations among different volcanoes could indicate a common underlying mechanism driving their activity and could help us interpreting the deeper common dynamics controlling their unrest. All the first evidences found testing the procedure, suggest the suitability of this analysis to investigate global volcanism related to plate tectonics. The first correlations found, in fact, indicate that an underlying common large-scale dynamics seems to drive volcanic activity at least around the Pacific plate, where it collides and subduces beneath American, Eurasian and Australian plates. From this still preliminary analysis, also more complex relationships among volcanoes lying on different tectonic margins have been found, suggesting some more complex interrelationships between different plates. The understanding of eventually detected correlations could be also used to further implement warning systems, relating the unrest probabilities of a specific volcano also to the ongoing activity to the correlated ones. Our preliminary results suggest that, as for other many physical and biological systems, an underlying organizing principle of planetary volcanoes activity might exist and it could be a small-world principle. In fact we found that, from a topological perspective, volcanoes correlations are characterized by the typical features of small-world network: a high clustering coefficient and a low characteristic path length. These features confirm that global volcanoes activity is characterized by both short and long-range correlations. We stress here the fact that numerical simulation carried out in this work seems to agree with geological evidences (eg. the Pacific plate, South America volcanoes activity and so on). However a detailed analysis of numerical correlation pointed out in this work and geological implication requires a lot of effort and is still running. Thus this work represents preliminary contribution to better understand and clarify, from a geophysical point of view, the nature of planetary correlations among active volcanoes. Further work is still needed.

The Role of Slope in the Fill and Spill Process of Linked Submarine Minibasins. Model Validation and Numerical Runs at Laboratory Scale.

NASA Astrophysics Data System (ADS)

Bastianon, E.; Viparelli, E.; Cantelli, A.; Imran, J.

2015-12-01

Primarily motivated by applications to hydrocarbon exploration, submarine minibasins have been widely studied during recent decades to understand the physical phenomenon that characterizes their fill process. Minibasins were identified in seismic records in the Gulf of Mexico, Angola, Trinidad and Tobago, Ireland, Nigeria and also in outcrops (e.g., Tres Pasos Formation, southern Chile). The filling of minibasis is generally described as the 'fill-and-spill' process, i.e. turbidity currents enter, are reflected on the minibasin flanks, pond and deposit suspended sediment. As the minibasin fills the turbidity current spills on the lowermost zone of the basin flank -spill point - and start filling the next basin downdip. Different versions of this simplified model were used to interpret field and laboratory data but it is still unclear how the minibasin size compared to the magnitude of the turbidity currents, the position of each basin in the system, and the slope of the minibasin system affects the characteristics of the deposit (e.g., geometry, grain size). Here, we conduct a numerical study to investigate how the 'fill-and-spill' model changes with increase in slopes of the minibasin system. First, we validate our numerical results against laboratory experiment performed on two linked minibasins located on a horizontal platform by comparing measured and simulated deposit geometries, suspended sediment concentration profiles and grain sizes. We then perform numerical simulations by increasing the minibasin system slope: deposit and flow characteristics are compared with the case of horizontal platform to identify how the depositional processes change. For the numerical study we used a three-dimensional numerical model of turbidity currents that solves the Reynolds-averaged Navier-Stokes equations for dilute suspensions. Turbulence is modeled by a buoyancy-modified k-ɛ closure. The numerical model has a deforming bottom boundary, to model the changes in the bed deposit due to erosion and deposition. Preliminary two dimensional simulations show that in the early stages of the fill process the suspended sediment concentration is higher in the first basin than in the second one, the coarse grain sizes are preferentially trapped in the updip basins and the fine sediment fractions spill into downdip basins.

The NASA Juncture Flow Experiment: Goals, Progress, and Preliminary Testing (Invited)

NASA Technical Reports Server (NTRS)

Rumsey, Christopher L.; Neuhart, Danny H.; Kegerise, Michael A.

2016-01-01

NASA has been working toward designing and conducting a juncture flow experiment on a wing-body aircraft configuration. The experiment is planned to provide validation-quality data for CFD that focuses on the onset and progression of a separation bubble near the wing-body juncture trailing edge region. This paper describes the goals and purpose of the experiment. Although currently considered unreliable, preliminary CFD analyses of several different configurations are shown. These configurations have been subsequently tested in a series of "risk-reduction" wind tunnel tests, in order to help down-select to a final configuration that will attain the desired flow behavior. The risk-reduction testing at the higher Reynolds number has not yet been completed (at the time of this writing), but some results from one of the low-Reynolds-number experiments are shown.

What goes up might come down: Backflow in the conduits of persistently degassing volcanoes and ramifications for melt-inclusion analysis

NASA Astrophysics Data System (ADS)

Suckale, J.; Qin, Z.; Picchi, D.; Keller, T.

2017-12-01

Many active volcanoes erupt significantly less magma than they degas, implying that large quantities of magma must descend back into the plumbing system after degassing. The resulting bidirectional flow field in the volcanic conduit is fundamentally unstable. These instabilities are important to understand, because they likely control the episodicity of eruptive behavior observed at persistently degassing volcanoes. Laboratory experiments have provided invaluable insights into the flow regimes that may arise in volcanic conduits, but are not straightforward to scale up to volcanic systems. The goal of this study is to use direct numerical simulations to virtually reproduce the analogue experiments by Stevenson and Blake, 1998, compare them to simple analytical models and gain insights into the different flow regimes and interface instabilities observed in actual volcanic conduits. Direct numerical simulations provide a compelling complement to analogue experiments, because they are not constrained by the scales or flow properties achievable in a laboratory setting. By linking virtual and analogue experiments, we show that the interface between ascending and descending fluid is not usually stationary in volcanic conduits (see fig). The intuition that buoyant, volatile-rich magma moves up while heavy, degassed magma moves down is hence not generally true in bidirectional conduit flow. Instead, our results show that a potentially significant portion of the volatile-rich magma flows downwards despite its positive buoyancy - a process commonly referred to as backflow. The existence of backflow in volcanic conduits has potentially important ramifications for understanding melt-inclusion trends, because it affects exsolved and dissolved volatile components differently. Our preliminary results suggest that carbon dioxide bubbles exsolved at depth tend to decouple from the backflow and escape into the upward moving portion of the fluid, while dissolved water is recycled back to depth. The ascending magma, which is likely sampled by eruptive products, is hence enriched in carbon dioxide but deprived of water, which could be reflected in the common observation that melt inclusions from persistently degassing volcanic systems appear to be shifted to higher carbon dioxide contents for a given amount of water.

Numerical simulation of coupled electrochemical and transport processes in battery systems

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

Liaw, B.Y.; Gu, W.B.; Wang, C.Y.

1997-12-31

Advanced numerical modeling to simulate dynamic battery performance characteristics for several types of advanced batteries is being conducted using computational fluid dynamics (CFD) techniques. The CFD techniques provide efficient algorithms to solve a large set of highly nonlinear partial differential equations that represent the complex battery behavior governed by coupled electrochemical reactions and transport processes. The authors have recently successfully applied such techniques to model advanced lead-acid, Ni-Cd and Ni-MH cells. In this paper, the authors briefly discuss how the governing equations were numerically implemented, show some preliminary modeling results, and compare them with other modeling or experimental data reportedmore » in the literature. The authors describe the advantages and implications of using the CFD techniques and their capabilities in future battery applications.« less

System Management in UK Libraries: Some Preliminary Findings of a Survey.

ERIC Educational Resources Information Center

Muirhead, Graeme A.

1992-01-01

A cross-section of libraries in the United Kingdom was surveyed to investigate the prevalence of systems librarians and their education, work experience, duties, and professional activities. Preliminary findings of one section of the questionnaire indicate that systems librarians are generally associated with larger institutions that have large…

Impact of diet on the design of waste processors in CELSS

NASA Technical Reports Server (NTRS)

Waleh, Ahmad; Kanevsky, Valery; Nguyen, Thoi K.; Upadhye, Ravi; Wydeven, Theodore

1991-01-01

The preliminary results of a design analysis for a waste processor which employs existing technologies and takes into account the constraints of human diet are presented. The impact of diet is determined by using a model and an algorithm developed for the control and management of diet in a Controlled Ecological Life Support System (CELSS). A material and energy balance model for thermal oxidation of waste is developed which is consistent with both physical/chemical methods of incineration and supercritical water oxidation. The two models yield quantitative analysis of the diet and waste streams and the specific design parameters for waste processors, respectively. The results demonstrate that existing technologies can meet the demands of waste processing, but the choice and design of the processors or processing methods will be sensitive to the constraints of diet. The numerical examples are chosen to display the nature and extent of the gap in the available experiment information about CELSS requirements.

A Model of Regularization Parameter Determination in Low-Dose X-Ray CT Reconstruction Based on Dictionary Learning.

PubMed

Zhang, Cheng; Zhang, Tao; Zheng, Jian; Li, Ming; Lu, Yanfei; You, Jiali; Guan, Yihui

2015-01-01

In recent years, X-ray computed tomography (CT) is becoming widely used to reveal patient's anatomical information. However, the side effect of radiation, relating to genetic or cancerous diseases, has caused great public concern. The problem is how to minimize radiation dose significantly while maintaining image quality. As a practical application of compressed sensing theory, one category of methods takes total variation (TV) minimization as the sparse constraint, which makes it possible and effective to get a reconstruction image of high quality in the undersampling situation. On the other hand, a preliminary attempt of low-dose CT reconstruction based on dictionary learning seems to be another effective choice. But some critical parameters, such as the regularization parameter, cannot be determined by detecting datasets. In this paper, we propose a reweighted objective function that contributes to a numerical calculation model of the regularization parameter. A number of experiments demonstrate that this strategy performs well with better reconstruction images and saving of a large amount of time.

Stacking Defects in Synthetic and Meteoritic Hibonites: Implications for High-Temperature Processes in the Solar Nebula

NASA Technical Reports Server (NTRS)

Han, J.; Keller, L. P.; Brearley, A. J.; Danielson, L. R.

2016-01-01

Hibonite (CaAl12O19) is a primary, highly refractory phase occurring in many Ca-Al-rich inclusions (CAIs) from different chondrite groups, except CI chondrites. Hibonite is predicted to be one of the earliest minerals to condense during cooling of the solar nebula at higher temperatures than any other major CAI mineral. Therefore, hibonite has great potential to reveal the processes and conditions of the very early, high-temperature stages of the solar nebular evolution. Previous microstructural studies of hibonite in CAIs and their Wark-Lovering (WL) rims showed the presence of numerous stacking defects in hibonite. These defects are interpreted as the modification of the stacking sequences of spinel and Ca-containing blocks within the ideal hexagonal hibonite structure, as shown by experimental studies of reaction-sintered ceramic CaO-Al2O3 compounds. We performed preliminary experiments in the CaO-Al2O3-MgO system to understand the formation processes and conditions of defect-structured hibonite found in meteorites.

A cellular automaton for the signed particle formulation of quantum mechanics

NASA Astrophysics Data System (ADS)

Sellier, J. M.; Kapanova, K. G.; Dimov, I.

2017-02-01

Recently, a new formulation of quantum mechanics, based on the concept of signed particles, has been suggested. In this paper, we introduce a cellular automaton which mimics the dynamics of quantum objects in the phase-space in a time-dependent fashion. This is twofold: it provides a simplified and accessible language to non-physicists who wants to simulate quantum mechanical systems, at the same time it enables a different way to explore the laws of Physics. Moreover, it opens the way towards hybrid simulations of quantum systems by combining full quantum models with cellular automata when the former fail. In order to show the validity of the suggested cellular automaton and its combination with the signed particle formalism, several numerical experiments are performed, showing very promising results. Being this article a preliminary study on quantum simulations in phase-space by means of cellular automata, some conclusions are drawn about the encouraging results obtained so far and the possible future developments.

Gravitational Instabilities in Gaseous Protoplanetary Disks and Implications for Giant Planet Formation

NASA Astrophysics Data System (ADS)

Durisen, R. H.; Boss, A. P.; Mayer, L.; Nelson, A. F.; Quinn, T.; Rice, W. K. M.

Protoplanetary gas disks are likely to experience gravitational instabilities (GIs) during some phase of their evolution. Density perturbations in an unstable disk grow on a dynamic timescale into spiral arms that produce efficient outward transfer of angular momentum and inward transfer of mass through gravitational torques. In a cool disk with sufficiently rapid cooling, the spiral arms in an unstable disk form self-gravitating clumps. Whether gas giant protoplanets can form by such a disk instability process is the primary question addressed by this review. We discuss the wide range of calculations undertaken by ourselves and others using various numerical techniques, and we report preliminary results from a large multicode collaboration. Additional topics include triggering mechanisms for GIs, disk heating and cooling, orbital survival of dense clumps, interactions of solids with GI-driven waves and shocks, and hybrid scenarios where GIs facilitate core accretion. The review ends with a discussion of how well disk instability and core accretion fare in meeting observational constraints.

Simulation-based hypothesis testing of high dimensional means under covariance heterogeneity.

PubMed

Chang, Jinyuan; Zheng, Chao; Zhou, Wen-Xin; Zhou, Wen

2017-12-01

In this article, we study the problem of testing the mean vectors of high dimensional data in both one-sample and two-sample cases. The proposed testing procedures employ maximum-type statistics and the parametric bootstrap techniques to compute the critical values. Different from the existing tests that heavily rely on the structural conditions on the unknown covariance matrices, the proposed tests allow general covariance structures of the data and therefore enjoy wide scope of applicability in practice. To enhance powers of the tests against sparse alternatives, we further propose two-step procedures with a preliminary feature screening step. Theoretical properties of the proposed tests are investigated. Through extensive numerical experiments on synthetic data sets and an human acute lymphoblastic leukemia gene expression data set, we illustrate the performance of the new tests and how they may provide assistance on detecting disease-associated gene-sets. The proposed methods have been implemented in an R-package HDtest and are available on CRAN. © 2017, The International Biometric Society.

Extension of sonic anemometry to high subsonic Mach number flows

NASA Astrophysics Data System (ADS)

Otero, R.; Lowe, K. T.; Ng, W. F.

2017-03-01

In the literature, the application of sonic anemometry has been limited to low subsonic Mach number, near-incompressible flow conditions. To the best of the authors’ knowledge, this paper represents the first time a sonic anemometry approach has been used to characterize flow velocity beyond Mach 0.3. Using a high speed jet, flow velocity was measured using a modified sonic anemometry technique in flow conditions up to Mach 0.83. A numerical study was conducted to identify the effects of microphone placement on the accuracy of the measured velocity. Based on estimated error strictly due to uncertainty in time-of-acoustic flight, a random error of +/- 4 m s-1 was identified for the configuration used in this experiment. Comparison with measurements from a Pitot probe indicated a velocity RMS error of +/- 9 m s-1. The discrepancy in error is attributed to a systematic error which may be calibrated out in future work. Overall, the experimental results from this preliminary study support the use of acoustics for high subsonic flow characterization.

UNISAT-3 Power System

NASA Astrophysics Data System (ADS)

Santoni, Fabio; Piergentili, Fabrizio; Bulgarelli, Fabio; Graziani, Filippo

2005-05-01

An overview of the UNISAT-3 microsatellite power subsystem is given. This is an educational, low weight and low cost microsatellite designed, built, launched and operated in space by students and professors of Scuola di Ingegneria Aerospaziale, at University of Rome "La Sapienza". The satellite power system is based on terrestrial technology solar arrays and NiCd batteries. The microsatellite hosts other solar arrays, including multi-junction solar cells and mono- crystalline silicon high efficiency solar cells, in order to compare their behaviour in orbit. Moreover a MPPT (Maximum Power Point Tracking ) system has been designed and tested, and it is a technological payload of UNISAT-3. The MPPT design follows the studies performed in the field of solar powered racing cars, with modifications to make the system suitable for use in space. The system design, numerical simulation and hardware ground testing are described in the paper. The experiment and the performance evaluation criterion are described, together with the preliminary results of the first eight months of operation in orbit.

Axisymmetric capillary-gravity waves at the interface of two viscous, immiscible fluids - Initial value problem

NASA Astrophysics Data System (ADS)

Farsoiya, Palas Kumar; Dasgupta, Ratul

2017-11-01

When the interface between two radially unbounded, viscous fluids lying vertically in a stable configuration (denser fluid below) at rest, is perturbed, radially propagating capillary-gravity waves are formed which damp out with time. We study this process analytically using a recently developed linearised theory. For small amplitude initial perturbations, the analytical solution to the initial value problem, represented as a linear superposition of Bessel modes at time t = 0 , is found to agree very well with results obtained from direct numerical simulations of the Navier-Stokes equations, for a range of initial conditions. Our study extends the earlier work by John W. Miles who studied this initial value problem analytically, taking into account, a single viscous fluid only. Implications of this study for the mechanistic understanding of droplet impact into a deep pool, will be discussed. Some preliminary, qualitative comparison with experiments will also be presented. We thank SERB Dept. Science & Technology, Govt. of India, Grant No. EMR/2016/000830 for financial support.

Vertical structure of aerosol distribution and radiative properties over Svalbard - observations and modelling

NASA Astrophysics Data System (ADS)

Kaminski, Jacek W.; Struzewska, Joanna; Markowicz, Krzysztof; Jefimow, Maciej

2015-04-01

In the scope of the iAREA projects (Impact of absorbing aerosols on radiative forcing in the European Arctic - http://www.igf.fuw.edu.pl/iAREA) a field campaign was undertaken in March and April 2014 on Spitzbergen. Analysis of measurements was supported by the GEM-AQ model simulations. The GEM-AQ model is a chemical weather model. The core of the model is based on a weather prediction model with environmental processes (chemistry and aerosols) implanted on-line and are interactive (i.e. providing feedback of chemistry on radiation and dynamics). Numerical experiments were performed with the computational grid resolution of ˜15 km. The emission inventory developed by NILU in the ECLIPSE project was used. Preliminary analysis revealed small but systematic overestimation of modelled AOD and background BC levels. We will present the analysis of the vertical distribution of different aerosol species and its contribution to AOD for two stations on Svalbard. Also, changes of modelled chemical composition of aerosols with altitude will be analyzed.

Magnetic Inertial Confinement Fusion (MICF)

NASA Astrophysics Data System (ADS)

Miao, Feng; Zheng, Xianjun; Deng, Baiquan; Liu, Wei; Ou, Wei; Huang, Yi

2016-11-01

Based on the similarity in models of the early Sun and the 3-D common focal region of the micro-pinch in X-pinch experiments, a novel hybrid fusion configuration by continuous focusing of multiple Z-pinched plasma beams on spatially symmetric plasma is proposed. By replacing gravity with Lorentz force with subsequent centripetal spherical pinch, the beam-target fusion reactivity is enhanced in a quasi-spherical converging region, thus achieving MICF. An assessment, presented here, suggests that a practical fusion power source could be achieved using deuterium alone. Plasma instabilities can be suppressed by fast rotation resulting from an asymmetric tangential torsion in the spherical focal region of this configuration. Mathematical equivalence with the Sun allows the development of appropriate equations for the focal region of MICF, which are solved numerically to provide density, temperature and pressure distributions that produce net fusion energy output. An analysis of MICF physics and a preliminary experimental demonstration of a single beam are also carried out. supported by National Natural Science Foundation of China (Nos. 11374217 and 11176020)

A preliminary assessment of the Nactus pelagicus species group (Squamata: Gekkonidae) in New Guinea and a new species from the Admiralty Islands

USGS Publications Warehouse

Zug, George R.; Fisher, Robert N.

2012-01-01

The Slender-toed Geckos (Nactus) currently have four recognized species in New Guinea, and these species divide into two sister clades: a pelagicus clade and a vankampeni clade (Heinicke et al. 2010). The latter contains three dwarf species. The former consists of five bisexual populations, of which numerous New Guinea populations are uncharacterized nomenclaturally and lumped under the epithet ‘pelagicus.’ This report and description of a new species of the pelagicus group from Manus Island in the Admiralty Islands encourages us to offer a preliminary assessment of morphology and diversity in New Guinea ‘pelagicus’ populations.

Orbit computation of the TELECOM-2D satellite with a Genetic Algorithm

NASA Astrophysics Data System (ADS)

Deleflie, Florent; Coulot, David; Vienne, Alain; Decosta, Romain; Richard, Pascal; Lasri, Mohammed Amjad

2014-07-01

In order to test a preliminary orbit determination method, we fit an orbit of the geostationary satellite TELECOM-2D, as if we did not know any a priori information on its trajectory. The method is based on a genetic algorithm coupled to an analytical propagator of the trajectory, that is used over a couple of days, and that uses a whole set of altazimutal data that are acquired by the tracking network made up of the two TAROT telescopes. The adjusted orbit is then compared to a numerical reference. The method is described, and the results are analyzed, as a step towards an operational method of preliminary orbit determination for uncatalogued objects.

The 7.2 magnitude earthquake, November 1975, Island of Hawaii

USGS Publications Warehouse

1976-01-01

It was centered about 5 km beneath the Kalapana area on the southeastern coast of Hawaii, the largest island of the Hawaiian chain (Fig. 1) and was preceded by numerous foreshocks. The event was accompanied, or followed shortly, by a tsunami, large-scale ground movemtns, hundreds of aftershocks, an eruption in the summit caldera of Kilauea Volcano. The earthquake and the tsunami it generated produced about 4.1 million dollars in property damage, and the tsumani caused two deaths. Although we have some preliminary findings about the cause and effects of the earthquake, detailed scientific investigations will take many more months to complete. This article is condensed from a recent preliminary report (Tillings an others 1976)

Predicting discovery rates of genomic features.

PubMed

Gravel, Simon

2014-06-01

Successful sequencing experiments require judicious sample selection. However, this selection must often be performed on the basis of limited preliminary data. Predicting the statistical properties of the final sample based on preliminary data can be challenging, because numerous uncertain model assumptions may be involved. Here, we ask whether we can predict "omics" variation across many samples by sequencing only a fraction of them. In the infinite-genome limit, we find that a pilot study sequencing 5% of a population is sufficient to predict the number of genetic variants in the entire population within 6% of the correct value, using an estimator agnostic to demography, selection, or population structure. To reach similar accuracy in a finite genome with millions of polymorphisms, the pilot study would require ∼15% of the population. We present computationally efficient jackknife and linear programming methods that exhibit substantially less bias than the state of the art when applied to simulated data and subsampled 1000 Genomes Project data. Extrapolating based on the National Heart, Lung, and Blood Institute Exome Sequencing Project data, we predict that 7.2% of sites in the capture region would be variable in a sample of 50,000 African Americans and 8.8% in a European sample of equal size. Finally, we show how the linear programming method can also predict discovery rates of various genomic features, such as the number of transcription factor binding sites across different cell types. Copyright © 2014 by the Genetics Society of America.

First Continuous High Frequency in Situ Measurements of CO2 and CH4 in Rwanda Using Cavity Ring-Down Spectroscopy, and Preliminary Results of Regional Emission Estimation

NASA Astrophysics Data System (ADS)

Gasore, J.; Prinn, R. G.

2016-12-01

Recent IPCC reports emphasize the lack of ground measurements of greenhouse gases on the African continent, despite Africa's significant emissions from agriculture and biomass burning as well as ongoing land use changes. We have established a greenhouse gas monitoring station in northern Rwanda that will be part of the Advanced Global Atmospheric Gases Experiment (AGAGE), a global network of high frequency long-term remote atmospheric measurement stations. Using a Picarro G2401 cavity ring-down analyzer, continuous measurements of CO2, CH4, and CO at a frequency of five seconds are being captured at this equatorial East African site. The measurement site is located near the Virunga mountains, a volcanic range in North-West Rwanda, on the summit of Mt. Mugogo (2507 m above sea level). Mt. Mugogo is located in a rural area 70km away from Kigali, the capital of Rwanda, and about 13km from the nearest town. From HYSPLIT 7-day back-trajectory calculations, we have determined that the station measures air masses originating from East and Central Africa, the Indian Ocean and occasionally from Southern Asia. Here we present the first greenhouse gas measurement data from this understudied location in Africa. We also present preliminary results of regional CO2 and CH4emissions estimation from this unique dataset, using the Numerical Atmospheric-dispersion Modeling Environment (NAME) lagrangian particle dispersion model.

A Preliminary Lattice Study of the Glue in the Nucleon

NASA Astrophysics Data System (ADS)

Göckeler, M.; Horsley, R.; Ilgenfritz, E.-M.; Oelrich, H.; Perlt, H.; Rakow, P. E. L.; Schierholz, G.; Schiller, A.; Stephenson, P.

1997-02-01

About half the mass of a hadron is given from gluonic contributions. In this talk we calculate the chromoelectric and chromo-magnetic components of the nucleon mass. These computations are numerically difficult due to gluon field ultra-violet fluctuations. Nevertheless a high statistics feasibility run using quenched Wilson fermions seems to show reasonable signals.

Multilevel decomposition of complete vehicle configuration in a parallel computing environment

NASA Technical Reports Server (NTRS)

Bhatt, Vinay; Ragsdell, K. M.

1989-01-01

This research summarizes various approaches to multilevel decomposition to solve large structural problems. A linear decomposition scheme based on the Sobieski algorithm is selected as a vehicle for automated synthesis of a complete vehicle configuration in a parallel processing environment. The research is in a developmental state. Preliminary numerical results are presented for several example problems.

Polarized e-bunch acceleration at Cornell RCS: Tentative tracking simulations

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

Meot, F.; Ptitsyn, V.; Ranjbar, V.

2017-10-19

An option as an injector into eRHIC electron storage ring is a rapid-cyclic synchrotron (RCS). Rapid acceleration of polarized electron bunches has never been done, Cornell synchrotron might lend itself to dedicated tests, which is to be first explored based on numerical investigations. This paper is a very preliminary introduction to the topic.

Protein folding optimization based on 3D off-lattice model via an improved artificial bee colony algorithm.

PubMed

Li, Bai; Lin, Mu; Liu, Qiao; Li, Ya; Zhou, Changjun

2015-10-01

Protein folding is a fundamental topic in molecular biology. Conventional experimental techniques for protein structure identification or protein folding recognition require strict laboratory requirements and heavy operating burdens, which have largely limited their applications. Alternatively, computer-aided techniques have been developed to optimize protein structures or to predict the protein folding process. In this paper, we utilize a 3D off-lattice model to describe the original protein folding scheme as a simplified energy-optimal numerical problem, where all types of amino acid residues are binarized into hydrophobic and hydrophilic ones. We apply a balance-evolution artificial bee colony (BE-ABC) algorithm as the minimization solver, which is featured by the adaptive adjustment of search intensity to cater for the varying needs during the entire optimization process. In this work, we establish a benchmark case set with 13 real protein sequences from the Protein Data Bank database and evaluate the convergence performance of BE-ABC algorithm through strict comparisons with several state-of-the-art ABC variants in short-term numerical experiments. Besides that, our obtained best-so-far protein structures are compared to the ones in comprehensive previous literature. This study also provides preliminary insights into how artificial intelligence techniques can be applied to reveal the dynamics of protein folding. Graphical Abstract Protein folding optimization using 3D off-lattice model and advanced optimization techniques.

Heat Transfer of Thermocapillary Convection in a Two-Layered Fluid System Under the Influence of Magnetic Field

NASA Technical Reports Server (NTRS)

Ramachandran, N.; Ludovisis, D.; Cha, S. S.

2006-01-01

Heat transfer of a two-layer fluid system has been of great importance in a variety of industrial applications. For example, the phenomena of immiscible fluids can be found in materials processing and heat exchangers. Typically in solidification from a melt, the convective motion is the dominant factor that affects the uniformity of material properties. In the layered flow, thermocapillary forces can come into an important play, which was first emphasized by a previous investigator in 1958. Under extraterrestrial environments without gravity, thermocapillary effects can be a more dominant factor, which alters material properties in processing. Control and optimization of heat transfer in an immiscible fluid system need complete understanding of the flow phenomena that can be induced by surface tension at a fluid interface. The present work is focused on understanding of the magnetic field effects on thermocapillary convection, in order to optimize material processing. That is, it involves the study of the complicated phenomena to alter the flow motion in crystal growth. In this effort, the Marangoni convection in a cavity with differentially heated sidewalls is investigated with and without the influence of a magnetic field. As a first step, numerical analyses are performed, by thoroughly investigating influences of all pertinent physical parameters. Experiments are then conducted, with preliminary results, for comparison with the numerical analyses.

Experimental Validation of Normalized Uniform Load Surface Curvature Method for Damage Localization

PubMed Central

Jung, Ho-Yeon; Sung, Seung-Hoon; Jung, Hyung-Jo

2015-01-01

In this study, we experimentally validated the normalized uniform load surface (NULS) curvature method, which has been developed recently to assess damage localization in beam-type structures. The normalization technique allows for the accurate assessment of damage localization with greater sensitivity irrespective of the damage location. In this study, damage to a simply supported beam was numerically and experimentally investigated on the basis of the changes in the NULS curvatures, which were estimated from the modal flexibility matrices obtained from the acceleration responses under an ambient excitation. Two damage scenarios were considered for the single damage case as well as the multiple damages case by reducing the bending stiffness (EI) of the affected element(s). Numerical simulations were performed using MATLAB as a preliminary step. During the validation experiments, a series of tests were performed. It was found that the damage locations could be identified successfully without any false-positive or false-negative detections using the proposed method. For comparison, the damage detection performances were compared with those of two other well-known methods based on the modal flexibility matrix, namely, the uniform load surface (ULS) method and the ULS curvature method. It was confirmed that the proposed method is more effective for investigating the damage locations of simply supported beams than the two conventional methods in terms of sensitivity to damage under measurement noise. PMID:26501286

The dynamics and control of large flexible space structures - 12, supplement 11

NASA Technical Reports Server (NTRS)

Bainum, Peter M.; Reddy, A. S. S. R.; Li, Feiyue; Xu, Jianke

1989-01-01

The rapid 2-D slewing and vibrational control of the unsymmetrical flexible SCOLE (Spacecraft Control Laboratory Experiment) with multi-bounded controls is considered. Pontryagin's Maximum Principle is applied to the nonlinear equations of the system to derive the necessary conditions for the optimal control. The resulting two point boundary value problem is then solved by using the quasilinearization technique, and the near minimum time is obtained by sequentially shortening the slewing time until the controls are near the bang-bang type. The tradeoff between the minimum time and the minimum flexible amplitude requirements is discussed. The numerical results show that the responses of the nonlinear system are significantly different from those of the linearized system for rapid slewing. The SCOLE station-keeping closed loop dynamics are re-examined by employing a slightly different method for developing the equations of motion in which higher order terms in the expressions for the mast modal shape functions are now included. A preliminary study on the effect of actuator mass on the closed loop dynamics of large space systems is conducted. A numerical example based on a coupled two-mass two-spring system illustrates the effect of changes caused in the mass and stiffness matrices on the closed loop system eigenvalues. In certain cases the need for redesigning control laws previously synthesized, but not accounting for actuator masses, is indicated.

ECR plasma thruster research - Preliminary theory and experiments

NASA Technical Reports Server (NTRS)

Sercel, Joel C.; Fitzgerald, Dennis J.

1989-01-01

A preliminary theory of the operation of the electron-cyclotron-resonance (ECR) plasma thruster is described along with an outline of recent experiments. This work is presented to communicate the status of an ongoing research effort directed at developing a unified theory to quantitatively describe the operation of the ECR plasma thruster. The theory is presented as a set of nonlinear ordinary differential equations and boundary conditions which describe the plasma density, velocity, and electron temperature. Diagnostic tools developed to measure plasma conditions in the existing research device are described.

Sounding-Diagnosed Convective Environments and Preliminary Energy Budgets Diagnosed during the TRMM Field Campaigns

NASA Technical Reports Server (NTRS)

Halverson, Jeffrey B.; Roy, Biswadev; O'CStarr, David (Technical Monitor)

2002-01-01

An overview of mean convective thermodynamic and wind profiles for the Tropical Rainfall Measuring Mission (TRMM) Large Scale Biosphere-Atmosphere Experiment (LBA) and Kwajalein Experiment (KWAJEX) field campaigns will be presented, highlighting the diverse continental and marine tropical environments in which rain clouds and mesoscale convective systems evolved. An assessment of ongoing sounding quality control procedures will be shown. Additionally, we will present preliminary budgets of sensible heat source (Q1) and apparent moisture sink (Q2), which have been diagnosed from the various sounding networks.

New advances in the partial-reflection-drifts experiment using microprocessors

NASA Technical Reports Server (NTRS)

Ruggerio, R. L.; Bowhill, S. A.

1982-01-01

Improvements to the partial reflection drifts experiment are completed. The results of the improvements include real time processing and simultaneous measurements of the D region with coherent scatter. Preliminary results indicate a positive correlation between drift velocities calculated by both methods during a two day interval. The possibility now exists for extended observations between partial reflection and coherent scatter. In addition, preliminary measurements could be performed between partial reflection and meteor radar to complete a comparison of methods used to determine velocities in the D region.

Robotic Single-Site Surgery for Female-to-Male Transsexuals: Preliminary Experience

PubMed Central

Bogliolo, Stefano; Cassani, Chiara; Babilonti, Luciana; Gardella, Barbara; Zanellini, Francesca; Santamaria, Valentina; Nappi, Rossella Elena; Spinillo, Arsenio

2014-01-01

Hysterectomy with bilateral salpingo-oophorectomy is a part of gender reassignment surgery for the treatment of female-to-male transsexualism. Over the last years many efforts were made in order to reduce invasiveness of laparoscopic and robotic surgery such as the introduction of single-site approach. We report our preliminary experience on single-site robotic hysterectomy for cross-sex reassignment surgery. Our data suggest that single-site robotic hysterectomy is feasible and safe in female-to-male transsexualism with some benefits in terms of postoperative pain and aesthetic results. PMID:24982976

Accessing defect dynamics using intense, nanosecond pulsed ion beams

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

Persaud, A.; Barnard, J. J.; Guo, H.

2015-06-18

Gaining in-situ access to relaxation dynamics of radiation induced defects will lead to a better understanding of materials and is important for the verification of theoretical models and simulations. We show preliminary results from experiments at the new Neutralized Drift Compression Experiment (NDCX-II) at Lawrence Berkeley National Laboratory that will enable in-situ access to defect dynamics through pump-probe experiments. Here, the unique capabilities of the NDCX-II accelerator to generate intense, nanosecond pulsed ion beams are utilized. Preliminary data of channeling experiments using lithium and potassium ions and silicon membranes are shown. We compare these data to simulation results using Crystalmore » Trim. Furthermore, we discuss the improvements to the accelerator to higher performance levels and the new diagnostics tools that are being incorporated.« less

Spacelab payload accommodation handbook. Preliminary issue

NASA Technical Reports Server (NTRS)

1976-01-01

The main characteristics of the Spacelab system are described. Sufficient information on Spacelab capabilities is provided to enable individual experimenters or payload planning groups to determine how their payload equipment can be accomodated by Spacelab topics discussed include major spacelab/experiment interfaces; Spacelab payload support systems and requirements the experiments must comply with to allow experiment design; and development and integration up to a level where a group of individual experiments are integrated into a complete Spacelab payload using Spacelab racks/floors and pallet segments. Integration of a complete Spacelab payload with Spacelab subsystems, primary module structure etc., integration of Spacelab with the Orbiter and basic operational aspects are also covered in this preliminary edition of the handbook which reflects the current Spacelab baseline design and is for information only.

Introduction of Cooperative Vehicle-to-Infrastructure Systems to Improve Speed Harmonization

DOT National Transportation Integrated Search

2016-03-01

This project executed a preliminary experiment of vehicle-to-infrastructure (V2I)-based speed harmonization in which speed guidance was communicated directly to vehicles. This experiment involved a set of micro-simulation experiments and a limited nu...

Parametric analyses of planned flowing uranium hexafluoride critical experiments

NASA Technical Reports Server (NTRS)

Rodgers, R. J.; Latham, T. S.

1976-01-01

Analytical investigations were conducted to determine preliminary design and operating characteristics of flowing uranium hexafluoride (UF6) gaseous nuclear reactor experiments in which a hybrid core configuration comprised of UF6 gas and a region of solid fuel will be employed. The investigations are part of a planned program to perform a series of experiments of increasing performance, culminating in an approximately 5 MW fissioning uranium plasma experiment. A preliminary design is described for an argon buffer gas confined, UF6 flow loop system for future use in flowing critical experiments. Initial calculations to estimate the operating characteristics of the gaseous fissioning UF6 in a confined flow test at a pressure of 4 atm, indicate temperature increases of approximately 100 and 1000 K in the UF6 may be obtained for total test power levels of 100 kW and 1 MW for test times of 320 and 32 sec, respectively.

Possession experiences in dissociative identity disorder: a preliminary study.

PubMed

Ross, Colin A

2011-01-01

Dissociative trance disorder, which includes possession experiences, was introduced as a provisional diagnosis requiring further study in the Diagnostic and Statistical Manual of Mental Disorders (4th ed.). Consideration is now being given to including possession experiences within dissociative identity disorder (DID) in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.), which is due to be published in 2013. In order to provide empirical data relevant to the relationship between DID and possession states, I analyzed data on the prevalence of trance, possession states, sleepwalking, and paranormal experiences in 3 large samples: patients with DID from North America; psychiatric outpatients from Shanghai, China; and a general population sample from Winnipeg, Canada. Trance, sleepwalking, paranormal, and possession experiences were much more common in the DID patients than in the 2 comparison samples. The study is preliminary and exploratory in nature because the samples were not matched in any way.

A Preliminary Investigation of a Fluid-Filled ECG-Triggered Anti-G Suit.

DTIC Science & Technology

1994-02-01

the abdomen, anterior thighs, and calves. In Australia, Dr. F.S. Cotton of Sydney developed a pneumatic anti-G suit using the Royal Australian Air...Acceleration Stress: Model Studies and Preliminary Experiments. IEEE Transactions on Biomedical Engineering, Feb 1985, Vol BME -32(2):158-165. 10 13. Lambert

A Preliminary Assessment of Phase Separator Ground-Based and Reduced-Gravity Testing for ALS Systems

NASA Technical Reports Server (NTRS)

Hall, Nancy Rabel

2006-01-01

A viewgraph presentation of phase separator ground-based and reduced-gravity testing for Advanced Life Support (ALS) systems is shown. The topics include: 1) Multiphase Flow Technology Program; 2) Types of Separators; 3) MOBI Phase Separators; 4) Experiment set-up; and 5) Preliminary comparison/results.

ICT and UD: Preliminary Study for Recommendations to Design Accessible University Courses.

PubMed

Pagliara, Silvio Marcello; Sánchez Utgé, Marta; De Anna, Lucia

2017-01-01

Starting from the Universal Design in the educational context principles, the experiences gained during the FIRB project "Net@ccessibility" and the high-education courses for teachers' specialization on special education, this research will focus on preliminary studies in order to define the recommendations for designing accessible university courses.

Factors affecting weight gain and dietary intake in Latino males residing in Mississippi: A preliminary study

USDA-ARS?s Scientific Manuscript database

Research indicates that as Latinos become more acculturated to the United States, their diet changes and they experience weight gain. There is also a high incidence of depression in this population. The purpose of this preliminary study was to examine the correlations between sociodemographic factor...

Water in geodynamical models of mantle convection and plate tectonics

NASA Astrophysics Data System (ADS)

Rodríguez-González, J.; Van Hunen, J.; Chotalia, K.; Lithgow-Bertelloni, C. R.; Rozel, A.; Tackley, P. J.; Nakagawa, T.

2017-12-01

The presence of water in the the mantle has a significant effect in the dynamical and thermal evolution of Earth, which partially explains the differences with other planets and is a key factor for the presence of life on Earth. First, a small amount of water can decrease the mantle viscosity by a several orders of magnitude, thereby changing the convection regime and affecting the thermal evolution. Second, the presence of water significantly changes the solidus curve, with crucial implications for melting. Third, water in the mantle can change the Clapeyron slope of mantle materials, which changes the depth at which phase transitions take place. The thermal and dynamical evolution of Earth under the presence of water in the mantle has been the focus of recent studies, but many questions remain unanswered. In this project we intend to investigate how the maximum water capacity of different mantle regions affects water transport and Earth's convective regime. We will study the effect phase transitions under the presence of water, which can change the buoyancy of slabs in the transition zone. We present preliminary results numerical models of global mantle convection for the whole history of earth using the numerical geodynamics software tool StagYY. We will use a new parametrisation of dehydration processes, obtained from high-resolution numerical simulations, to implement a more accurate description of the water released from the slab as it travels through the mantle. We have integrated recent experimental results of the water capacity of deep mantle minerals to study the water circulation and the total water budget. We use data from the most recent experiments and ab-inito calculations to implement a realistic rheology.

Using SpF to Achieve Petascale for Legacy Pseudospectral Applications

NASA Technical Reports Server (NTRS)

Clune, Thomas L.; Jiang, Weiyuan

2014-01-01

Pseudospectral (PS) methods possess a number of characteristics (e.g., efficiency, accuracy, natural boundary conditions) that are extremely desirable for dynamo models. Unfortunately, dynamo models based upon PS methods face a number of daunting challenges, which include exposing additional parallelism, leveraging hardware accelerators, exploiting hybrid parallelism, and improving the scalability of global memory transposes. Although these issues are a concern for most models, solutions for PS methods tend to require far more pervasive changes to underlying data and control structures. Further, improvements in performance in one model are difficult to transfer to other models, resulting in significant duplication of effort across the research community. We have developed an extensible software framework for pseudospectral methods called SpF that is intended to enable extreme scalability and optimal performance. Highlevel abstractions provided by SpF unburden applications of the responsibility of managing domain decomposition and load balance while reducing the changes in code required to adapt to new computing architectures. The key design concept in SpF is that each phase of the numerical calculation is partitioned into disjoint numerical kernels that can be performed entirely inprocessor. The granularity of domain decomposition provided by SpF is only constrained by the datalocality requirements of these kernels. SpF builds on top of optimized vendor libraries for common numerical operations such as transforms, matrix solvers, etc., but can also be configured to use open source alternatives for portability. SpF includes several alternative schemes for global data redistribution and is expected to serve as an ideal testbed for further research into optimal approaches for different network architectures. In this presentation, we will describe our experience in porting legacy pseudospectral models, MoSST and DYNAMO, to use SpF as well as present preliminary performance results provided by the improved scalability.

The Impact of Sea Surface Temperature on Organized Convective Storms Crossing over Coastlines

NASA Astrophysics Data System (ADS)

Lombardo, K.

2016-02-01

As organized coastal convective storms develop over land and move over the coastal ocean, their storm-scale structures, intensity, and associated weather threats evolve. This study aims to quantify the impact of sea surface temperature on the fundamental mechanisms controlling the evolution of coastal quasi-linear convective systems (QLCSs) as they move offshore. Results from this work will contribute to the improved predictability of these coastal, potentially severe warm season storms. The current work systematically studies the interaction between QLCSs and marine atmospheric boundary layers (MABLs) associated with the coastal ocean in an idealized numerical framework. The initial simulations are run in 2-dimensions, with a 250 m horizontal resolution and a vertical resolution ranging from 100 m in the lowest 3000 m stretched to 250 m at the top of the 20 km domain. To create a numerical environment representative of a coastal region, the western half of the 800 km domain is configured to represent a land surface, while the eastern half represents a water surface. A series of sensitivity experiments are conducted to explore the influence of sea surface temperature and the overlying MABL on coastal QLCSs. Sea surface temperature values are selected to represent values observed within the Mid-Atlantic Bight coastal waters, including 5oC (min SST - January), 14oC (early summer), and 23oC (late summer). The numerical MABL is allowed to develop through surface heat fluxes. Preliminary simulations indicate that SST influences storm structure, with the stratiform precipitation shield becoming progressively wider as SST increases. SST also impacts propagation speed; once the storms are over the water, the early and late summer QLCSs move more quickly than the min SST storm. The physical mechanisms contributing to these and other differences will be discussed.

Lunar and Planetary Science XXXVI, Part 14

NASA Technical Reports Server (NTRS)

2005-01-01

Contents include the following: Destruction of Presolar Silicates by Aqueous Alteration Observed in Murchison CM2 Chondrite. Generation of Chondrule Forming Shock Waves in Solar Nebula by X-Ray Flares. TEM and NanoSIMS Study of Hydrated/Anhydrous Phase Mixed IDPs: Cometary or Asteroidal Origin? Inflight Calibration of Asteroid Multiband Imaging Camera Onboard Hayabusa: Preliminary Results. Corundum and Corundum-Hibonite Grains Discovered by Cathodoluminescence in the Matrix of Acfer 094 Meteorite. Spatial Extent of a Deep Moonquake Nest A Preliminary Report of Reexamination. Modal Abundances of Carbon in Ureilites: Implications for the Petrogenesis of Ureilites. Trapped Noble Gas Components and Exposure History of the Enstatite Chondrite ALH84206. Deep-seated Crustal Material in Dhofar Lunar Meteorites: Evidence from Pyroxene Chemistry. Numerical Investigations of Kuiper Belt Binaries. Dust Devils on Mars: Effects of Surface Roughness on Particle Threshold. Hecates Tholus, Mars: Nighttime Aeolian Activity Suggested by Thermal Images and Mesoscale Atmospheric Model Simulations. Are the Apollo 14 High-Al Basalts Really Impact Melts? Garnet in the Lunar Mantle: Further Evidence from Volcanic Glass Beads. The Earth/Mars Dichotomy in Mg/Si and Al/Si Ratios: Is It Real? Dissecting the Polar Asymmetry in the Non-Condensable Gas Enhancement on Mars: A Numerical Modeling Study. Cassini VIMS Preliminary Exploration of Titan s Surface Hemispheric Albedo Dichotomy. An Improved Instrument for Investigating Planetary Regolith Microstructure. Isotopic Composition of Oxygen in Lunar Zircons Preliminary Design of Visualization Tool for Hayabusa Operation. Size and Shape Distributions of Chondrules and Metal Grains Revealed by X-Ray Computed Tomography Data. Properties of Permanently Shadowed Regolith. Landslides in Interior Layered Deposits, Valles Marineris, Mars: Effects of Water and Ground Shaking on Slope Stability. Mars: Recent and Episodic Volcanic, Hydrothermal, and Glacial Activity Revealed by Mars Express High Resolution Stereo Camera (HRSC). The Cratering Record of the Saturnian Satellites Phoebe, Tethys, Dione and Iapetus in Comparison: First Results from Analysis of the Cassini ISS Imaging Data. Joint Crossover Solutions of Altimetry and Image Data on 433 Eros. The Martian Soil as a Geochemical Sink for.

Semi-Numerical Studies of the Three-Meter Spherical Couette Experiment Utilizing Data Assimilation

NASA Astrophysics Data System (ADS)

Burnett, S. C.; Rojas, R.; Perevalov, A.; Lathrop, D. P.

2017-12-01

The model of the Earth's magnetic field has been investigated in recent years through experiments and numerical models. At the University of Maryland, experimental studies are implemented in a three-meter spherical Couette device filled with liquid sodium. The inner and outer spheres of this apparatus mimic the planet's inner core and core-mantle boundary, respectively. These experiments incorporate high velocity flows with Reynolds numbers 108. In spherical Couette geometry, the numerical scheme applied to this work features finite difference methods in the radial direction and pseudospectral spherical harmonic transforms elsewhere [Schaeffer, N. G3 (2013)]. Adding to the numerical model, data assimilation integrates the experimental outer-layer magnetic field measurements. This semi-numerical model can then be compared to the experimental results as well as forecasting magnetic field changes. Data assimilation makes it possible to get estimates of internal motions of the three-meter experiment that would otherwise be intrusive or impossible to obtain in experiments or too computationally expensive with a purely numerical code. If we can provide accurate models of the three-meter device, it is possible to attempt to model the geomagnetic field. We gratefully acknowledge the support of NSF Grant No. EAR1417148 & DGE1322106.

Semi-Numerical Studies of the Three-Meter Spherical Couette Experiment Utilizing Data Assimilation

NASA Astrophysics Data System (ADS)

Burnett, Sarah; Rojas, Ruben; Perevalov, Artur; Lathrop, Daniel; Ide, Kayo; Schaeffer, Nathanael

2017-11-01

The model of the Earth's magnetic field has been investigated in recent years through experiments and numerical models. At the University of Maryland, experimental studies are implemented in a three-meter spherical Couette device filled with liquid sodium. The inner and outer spheres of this apparatus mimic the planet's inner core and core-mantle boundary, respectively. These experiments incorporate high velocity flows with Reynolds numbers 108 . In spherical Couette geometry, the numerical scheme applied to this work features finite difference methods in the radial direction and pseudospectral spherical harmonic transforms elsewhere. Adding to the numerical model, data assimilation integrates the experimental outer-layer magnetic field measurements. This semi-numerical model can then be compared to the experimental results as well as forecasting magnetic field changes. Data assimilation makes it possible to get estimates of internal motions of the three-meter experiment that would otherwise be intrusive or impossible to obtain in experiments or too computationally expensive with a purely numerical code. If we can provide accurate models of the three-meter device, it is possible to attempt to model the geomagnetic field. We gratefully acknowledge the support of NSF Grant No. EAR1417148 & DGE1322106.

Comparison-Bot: an Automated Preliminary-Final Report Comparison System.

PubMed

Kalaria, Amit D; Filice, Ross W

2016-06-01

Regular comparison of preliminary to final reports is a critical part of radiology resident and fellow education as prior research has documented substantial preliminary to final discrepancies. Unfortunately, there are many barriers to this comparison: high study volume; overnight rotations without an attending; the ability to finalize reports remotely; the subtle nature of many changes; and lack of easy access to the preliminary report after finalization. We developed a system that automatically compiles and emails a weekly summary of report differences for all residents and fellows. Trainees can also create a custom report using a date range of their choice and can view this data on a resident dashboard. Differences between preliminary and final reports are clearly highlighted with links to the associated study in Picture Archiving and Communication Systems (PACS) for efficient review and learning. Reports with more changes, particularly changes made in the impression, are highlighted to focus attention on those exams with substantive edits. Our system provides an easy way for trainees to review changes to preliminary reports with immediate access to the associated images, thereby improving their educational experience. Departmental surveys showed that our report difference summary is easy to understand and improves the educational experience of our trainees. Additionally, interesting descriptive statistics help us understand how reports are changed by trainee level, by attending, and by exam type. Finally, this system can be easily ported to other departments who have access to their Health Level 7 (HL7) data.

Numerical Simulations Of Flagellated Micro-Swimmers

NASA Astrophysics Data System (ADS)

Rorai, Cecilia; Markesteijn, Anton; Zaitstev, Mihail; Karabasov, Sergey

2017-11-01

We study flagellated microswimmers locomotion by representing the entire swimmer body. We discuss and contrast the accuracy and computational cost of different numerical approaches including the Resistive Force Theory, the Regularized Stokeslet Method and the Finite Element Method. We focus on how the accuracy of the methods in reproducing the swimming trajectories, velocities and flow field, compares to the sensitivity of these quantities to certain physical parameters, such as the body shape and the location of the center of mass. We discuss the opportunity and physical relevance of retaining inertia in our models. Finally, we present some preliminary results toward collective motion simulations. Marie Skodowska-Curie Individual Fellowship.

A statistical investigation of the single-point pdf of velocity and vorticity based on direct numerical simulations

NASA Technical Reports Server (NTRS)

Mortazavi, M.; Kollmann, W.; Squires, K.

1987-01-01

Vorticity plays a fundamental role in turbulent flows. The dynamics of vorticity in turbulent flows and the effect on single-point closure models were investigated. The approach was to use direct numerical simulations of turbulent flows to investigate the pdf of velocity and vorticity. The preliminary study of homogeneous shear flow has shown that the expectation of the fluctuating pressure gradient, conditioned with a velocity component, is linear in the velocity component, and that the coefficient is independent of velocity and vorticity. In addition, the work shows that the expectation of the pressure gradient, conditioned with a vorticity component, is essentially zero.

Modular space station phase B extension preliminary system design. Volume 3: Experiment analyses

NASA Technical Reports Server (NTRS)

Wengrow, G. L.; Lillenas, A. N.

1972-01-01

Experiment analysis tasks performed during program definition study are described. Experiment accommodation and scheduling, and defining and implementing the laboratory evolution are discussed. The general purpose laboratory requirements and concepts are defined, and supplemental studies are reported.

Cross-format physical similarity effects and their implications for the numerical cognition architecture

PubMed Central

Cohen, Dale J.; Warren, Erin; Blanc-Goldhammer, Daryn

2013-01-01

The sound |faiv| is visually depicted as a written number word “five” and as an Arabic digit “5.” Here, we present four experiments – two quantity same/different experiments and two magnitude comparison experiments – that assess whether auditory number words (|faiv|), written number words (“five”), and Arabic digits (“5”) directly activate one another and/or their associated quantity. The quantity same/different experiments reveal that the auditory number words, written number words, and Arabic digits directly activate one another without activating their associated quantity. That is, there are cross-format physical similarity effects but no numerical distance effects. The cross-format magnitude comparison experiments reveal significant effects of both physical similarity and numerical distance. We discuss these results in relation to the architecture of numerical cognition. PMID:23624377

Are Arabic and Verbal Numbers Processed in Different Ways?

ERIC Educational Resources Information Center

Kadosh, Roi Cohen; Henik, Avishai; Rubinsten, Orly

2008-01-01

Four experiments were conducted in order to examine effects of notation--Arabic and verbal numbers--on relevant and irrelevant numerical processing. In Experiment 1, notation interacted with the numerical distance effect, and irrelevant physical size affected numerical processing (i.e., size congruity effect) for both notations but to a lesser…

Numerical simulation of the actuation system for the ALDF's propulsion control valve. [Aircraft Landing Dynamics Facility

NASA Technical Reports Server (NTRS)

Korte, John J.

1990-01-01

A numerical simulation of the actuation system for the propulsion control valve (PCV) of the NASA Langley Aircraft Landing Dynamics Facility was developed during the preliminary design of the PCV and used throughout the entire project. The simulation is based on a predictive model of the PCV which is used to evaluate and design the actuation system. The PCV controls a 1.7 million-pound thrust water jet used in propelling a 108,000-pound test carriage. The PCV can open and close in 0.300 second and deliver over 9,000 gallons of water per sec at pressures up to 3150 psi. The numerical simulation results are used to predict transient performance and valve opening characteristics, specify the hydraulic control system, define transient loadings on components, and evaluate failure modes. The mathematical model used for numerically simulating the mechanical fluid power system is described, and numerical results are demonstrated for a typical opening and closing cycle of the PCV. A summary is then given on how the model is used in the design process.

Challenges to Applying a Metamodel for Groundwater Flow Beyond Underlying Numerical Model Boundaries

NASA Astrophysics Data System (ADS)

Reeves, H. W.; Fienen, M. N.; Feinstein, D.

2015-12-01

Metamodels of environmental behavior offer opportunities for decision support, adaptive management, and increased stakeholder engagement through participatory modeling and model exploration. Metamodels are derived from calibrated, computationally demanding, numerical models. They may potentially be applied to non-modeled areas to provide screening or preliminary analysis tools for areas that do not yet have the benefit of more comprehensive study. In this decision-support mode, they may be fulfilling a role often accomplished by application of analytical solutions. The major challenge to transferring a metamodel to a non-modeled area is how to quantify the spatial data in the new area of interest in such a way that it is consistent with the data used to derive the metamodel. Tests based on transferring a metamodel derived from a numerical groundwater-flow model of the Lake Michigan Basin to other glacial settings across the northern U.S. show that the spatial scale of the numerical model must be appropriately scaled to adequately represent different settings. Careful GIS analysis of the numerical model, metamodel, and new area of interest is required for successful transfer of results.

Preliminary Investigation on the Behavior of Pore Air Pressure During Rainfall Infiltration

NASA Astrophysics Data System (ADS)

Ashraf Mohamad Ismail, Mohd; Min, Ng Soon; Hasliza Hamzah, Nur; Hazreek Zainal Abidin, Mohd; Madun, Aziman; Tajudin, Saiful Azhar Ahmad

2018-04-01

This paper focused on the preliminary investigation of pore air pressure behaviour during rainfall infiltration in order to substantiate the mechanism of rainfall induced slope failure. The actual behaviour or pore air pressure during infiltration is yet to be clearly understood as it is regularly assumed as atmospheric. Numerical modelling of one dimensional (1D) soil column was utilized in this study to provide a preliminary insight of this highlighted uncertainty. Parametric study was performed by using rainfall intensities of 1.85 x 10-3m/s and 1.16 x 10-4m/s applied on glass beads to simulate intense and modest rainfall conditions. Analysis results show that the high rainfall intensity causes more development of pore air pressure compared to low rainfall intensity. This is because at high rainfall intensity, the rainwater cannot replace the pore air smoothly thus confining the pore air. Therefore, the effect of pore air pressure has to be taken into consideration particularly during heavy rainfall.

Application procedures for hydropower licenses, exemptions, and preliminary permits

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

Not Available

1982-04-01

This document provides essential information regarding the FERC's regulations and procedures for filing an application with the Commission for hydropower licenses, exemptions and preliminary permits. Each section is page numbered with a roman numeral followed by consecutive arabic numbering. The appendices are page numbered with an alphabetical prefix and consecutve page numbering within each section. The first section of this book contains background descriptions of the Commission's authority and regulations and serves as an introduction to the Commission's hydropower licensing program. Two general tables follow this introductory text and provide a quick reference to the types of applications and themore » relationship between the Commission's orders and regulations. Following the introduction are sections which include the Commission's regulations by application type: preliminary permits; licenses; and exemptions. Each section contains an introduction describing application procedures by type of action requested. There are two appendices provided contain information on the consultation process and lists of agencies to be consulted and a section by section analyses of the Commission's orders.« less

Defining resilience: A preliminary integrative literature review

USGS Publications Warehouse

Wilt, Bonnie; Long, Suzanna K.; Shoberg, Thomas G.

2016-01-01

The term “resilience” is ubiquitous in technical literature; it appears in numerous forms, such as resilience, resiliency, or resilient, and each use may have a different definition depending on the interpretation of the writer. This creates difficulties in understanding what is meant by ‘resilience’ in any given use case, especially in discussions of interdisciplinary research. To better understand this problem, this research constructs a preliminary integrative literature review to map different definitions, applications and calculation methods of resilience invoked within critical infrastructure applications. The preliminary review uses a State-of-the-Art Matrix (SAM) analysis to characterize differences in definition across disciplines and between regions. Qualifying the various usages of resilience will produce a greater precision in the literature and a deeper insight into types of data required for its evaluation, particularly with respect to critical infrastructure calculations and how such data may be analyzed. Results from this SAM analysis will create a framework of key concepts as part of the most common applications for “resilient critical infrastructure” modeling.

Inertial migration of deformable droplets in a microchannel

NASA Astrophysics Data System (ADS)

Chen, Xiaodong; Xue, Chundong; Zhang, Li; Hu, Guoqing; Jiang, Xingyu; Sun, Jiashu

2014-11-01

The microfluidic inertial effect is an effective way of focusing and sorting droplets suspended in a carrier fluid in microchannels. To understand the flow dynamics of microscale droplet migration, we conduct numerical simulations on the droplet motion and deformation in a straight microchannel. The results are compared with preliminary experiments and theoretical analysis. In contrast to most existing literature, the present simulations are three-dimensional and full length in the streamwise direction and consider the confinement effects for a rectangular cross section. To thoroughly examine the effect of the velocity distribution, the release positions of single droplets are varied in a quarter of the channel cross section based on the geometrical symmetries. The migration dynamics and equilibrium positions of the droplets are obtained for different fluid velocities and droplet sizes. Droplets with diameters larger than half of the channel height migrate to the centerline in the height direction and two equilibrium positions are observed between the centerline and the wall in the width direction. In addition to the well-known Segré-Silberberg equilibrium positions, new equilibrium positions closer to the centerline are observed. This finding is validated by preliminary experiments that are designed to introduce droplets at different initial lateral positions. Small droplets also migrate to two equilibrium positions in the quarter of the channel cross section, but the coordinates in the width direction are between the centerline and the wall. The equilibrium positions move toward the centerlines with increasing Reynolds number due to increasing deformations of the droplets. The distributions of the lift forces, angular velocities, and the deformation parameters of droplets along the two confinement direction are investigated in detail. Comparisons are made with theoretical predictions to determine the fundamentals of droplet migration in microchannels. In addition, existence of the inner equilibrium position is linked to the quartic velocity distribution in the width direction through a simple model for the slip angular velocities of droplets.

Molten-Metal Droplet Deposition on a Moving Substrate in Microgravity: Aiding the Development of Novel Technologies for Microelectronic Assembly

NASA Technical Reports Server (NTRS)

Megaridis, C. M.; Bayer, I. S.; Poulikakos, D.; Nayagam, V.

2002-01-01

Driven by advancements in microelectronics manufacturing, this research investigates the oblique (non-axisymmetric) impact of liquid-metal droplets on flat substrates. The problem of interest is relevant to the development of the novel technology of on-demand dispension (printing) of microscopic solder deposits for the surface mounting of microelectronic devices. The technology, known as solder jetting, features on-demand deposition of miniature solder droplets (30 to 120 microns in diameter) in very fine, very accurate patterns using techniques analogous to those developed for the ink-jet printing industry. Despite its promise, severe limitations exist currently with regards to the throughput rates of the technology; some of these limitations are largely due to the lack of the capability for reliable prediction of solder bump positioning and shapes, especially under ballistic deposition conditions where the droplet impact phenomena are inherently three-dimensional. The study consists of a theoretical and an experimental component. The theoretical work uses a finite element formulation to simulate numerically the non-axisymmetric (3-D) fluid mechanics and heat transfer phenomena of a liquid solder droplet impacting at an angle alpha on a flat substrate. The work focuses on the pre-solidification regime. The modeling of the most challenging fluid mechanics part of the process has been completed successfully. It is based upon the full laminar Navier-Stokes equations employing a Lagrangian frame of reference. Due to the large droplet deformation, the surface (skin) as well as the volumetric mesh have to be regenerated during the calculations in order to maintain the high accuracy of the numerical scheme. The pressure and velocity fields are then interpolated on the newly created mesh. The numerical predictions are being tested against experiments, for cases where wetting phenomena are not important. For the impact parameters used in the example shown (We = 2.38, Fr = 16300, Re = 157), the droplet rolls along the substrate, but its shape remains practically axisymmetric for all impact angles within the range from 0 to 60 deg. Interestingly, the substrate/droplet contact area during the recoiling phase of the impact is not a monotonically decreasing function of time. The experimental component of the research tests the numerical predictions and provides necessary input data (contact angles) for the theoretical model. The experiments are performed in microgravity (2.2s drop tower of the NASA GRC) in order to allow for the use of mm-size solder droplets, which make feasible the performance of accurate measurements, while maintaining similitude of the relevant fluid dynamic groups (Re, Fr, We, Ste). Preliminary oblique impact experiments have been performed using water droplets in normal gravity.

Percutaneous treatment of transplant renal artery stenosis in children.

PubMed

Repetto, Horacio A; Rodríguez-Rilo, Laila; Mendaro, Esteban; Basso, Laura; Galvez, Hugo; Morrone, Gabriela; Vazquez, Luis A

2004-12-01

Percutaneous treatment of renal artery stenosis (RAS) is an accepted procedure and numerous reports have been published. However, experience with its use in RAS in the transplanted kidney in children is scarce. Since 1994 we have diagnosed RAS in seven children with the use of Doppler ultrasonography (US), confirming it with percutaneous angiography (PAG). In six of the seven patients percutaneous transluminal angioplasty (PTA) was performed. In one patient a metallic stent was placed due to the extension of the arterial lesion, and a second stent was placed in another child when a re-stenosis was diagnosed 1 month after the PTA. All patients presented with hypertension (de novo or 30% increase over previous values). After ruling out acute rejection, calcineurin inhibitor toxicity, and urinary obstruction, US was performed and, when an increase in arterial flux velocity was registered, PAG was also performed. Six children showed an increase in serum creatinine (Cr) and proteinuria. Blood pressure decreased after the procedure and Cr returned to previous levels in all children. One of the grafts was lost due to chronic transplant rejection 7 years later. The other children have a functioning kidney. Although this is a small group of patients, the consistently good results and the lack of reported experience prompted us to communicate our preliminary observation.

Preliminary SPE Phase II Far Field Ground Motion Estimates

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

Steedman, David W.

2014-03-06

Phase II of the Source Physics Experiment (SPE) program will be conducted in alluvium. Several candidate sites were identified. These include existing large diameter borehole U1e. One criterion for acceptance is expected far field ground motion. In June 2013 we were requested to estimate peak response 2 km from the borehole due to the largest planned SPE Phase II experiment: a contained 50- Ton event. The cube-root scaled range for this event is 5423 m/KT 1/3. The generally accepted first order estimate of ground motions from an explosive event is to refer to the standard data base for explosive eventsmore » (Perrett and Bass, 1975). This reference is a compilation and analysis of ground motion data from numerous nuclear and chemical explosive events from Nevada National Security Site (formerly the Nevada Test Site, or NTS) and other locations. The data were compiled and analyzed for various geologic settings including dry alluvium, which we believe is an accurate descriptor for the SPE Phase II setting. The Perrett and Bass plots of peak velocity and peak yield-scaled displacement, both vs. yield-scaled range, are provided here. Their analysis of both variables resulted in bi-linear fits: a close-in non-linear regime and a more distant linear regime.« less

Imaging through ground-level turbulence by Fourier telescopy: Simulations and preliminary experiments

NASA Astrophysics Data System (ADS)

Randunu Pathirannehelage, Nishantha

Fourier telescopy imaging is a recently-developed imaging method that relies on active structured-light illumination of the object. Reflected/scattered light is measured by a large "light bucket" detector; processing of the detected signal yields the magnitude and phase of spatial frequency components of the object reflectance or transmittance function. An inverse Fourier transform results in the image. In 2012 a novel method, known as time-average Fourier telescopy (TAFT), was introduced by William T. Rhodes as a means for diffraction-limited imaging through ground-level atmospheric turbulence. This method, which can be applied to long horizontal-path terrestrial imaging, addresses a need that is not solved by the adaptive optics methods being used in astronomical imaging. Field-experiment verification of the TAFT concept requires instrumentation that is not available at Florida Atlantic University. The objective of this doctoral research program is thus to demonstrate, in the absence of full-scale experimentation, the feasibility of time-average Fourier telescopy through (a) the design, construction, and testing of small-scale laboratory instrumentation capable of exploring basic Fourier telescopy data-gathering operations, and (b) the development of MATLAB-based software capable of demonstrating the effect of kilometer-scale passage of laser beams through ground-level turbulence in a numerical simulation of TAFT.

Selective Injection of Magnetization by Slow Chemical Exchange in NMR

NASA Astrophysics Data System (ADS)

Boulat, Benoit; Epstein, David M.; Rance, Mark

1999-06-01

In a system in slow dynamic equilibrium two NMR methods are shown to be suitable for injecting magnetization from one resonance to another by means of slow chemical exchange. The combined outputs of the methods may be employed to measure the value of the off-rate constant κoff in the complex. The methods are implemented experimentally using the complex of molecules composed of the enzyme Esherichia coli dihydrofolate reductase (DHFR) and the ligand folate. In an equilibrium solution with DHFR, folate is known to undergo chemical exchange between a free state and a bound state. The modified synchronous nutation method is applied to a spin of the folate molecule in the free and bound states; magnetization transfer occurs between the two sites due to the underlying exchange process. As a preliminary step for the application of the synchronous nutation method, a new one-dimensional 1H NMR technique is proposed which facilitates the assignment of the resonance of a spin in the bound state, provided the resonance of its exchange partner in the free state is known. This experiment is also used to obtain quantitative estimates of the transverse relaxation rate constant of the bound resonance. The numerical procedure necessary to analyze the experimental results of the synchronous nutation experiment is presented.

A micromechanical constitutive model for the dynamic response of brittle materials "Dynamic response of marble"

NASA Astrophysics Data System (ADS)

Haberman, Keith

2001-07-01

A micromechanically based constitutive model for the dynamic inelastic behavior of brittle materials, specifically "Dionysus-Pentelicon marble" with distributed microcracking is presented. Dionysus-Pentelicon marble was used in the construction of the Parthenon, in Athens, Greece. The constitutive model is a key component in the ability to simulate this historic explosion and the preceding bombardment form cannon fire that occurred at the Parthenon in 1678. Experiments were performed by Rosakis (1999) that characterized the static and dynamic response of this unique material. A micromechanical constitutive model that was previously successfully used to model the dynamic response of granular brittle materials is presented. The constitutive model was fitted to the experimental data for marble and reproduced the experimentally observed basic uniaxial dynamic behavior quite well. This micromechanical constitutive model was then implemented into the three dimensional nonlinear lagrangain finite element code Dyna3d(1998). Implementing this methodology into the three dimensional nonlinear dynamic finite element code allowed the model to be exercised on several preliminary impact experiments. During future simulations, the model is to be used in conjunction with other numerical techniques to simulate projectile impact and blast loading on the Dionysus-Pentelicon marble and on the structure of the Parthenon.

A Numerical-Analytical Approach Based on Canonical Transformations for Computing Optimal Low-Thrust Transfers

NASA Astrophysics Data System (ADS)

da Silva Fernandes, S.; das Chagas Carvalho, F.; Bateli Romão, J. V.

2018-04-01

A numerical-analytical procedure based on infinitesimal canonical transformations is developed for computing optimal time-fixed low-thrust limited power transfers (no rendezvous) between coplanar orbits with small eccentricities in an inverse-square force field. The optimization problem is formulated as a Mayer problem with a set of non-singular orbital elements as state variables. Second order terms in eccentricity are considered in the development of the maximum Hamiltonian describing the optimal trajectories. The two-point boundary value problem of going from an initial orbit to a final orbit is solved by means of a two-stage Newton-Raphson algorithm which uses an infinitesimal canonical transformation. Numerical results are presented for some transfers between circular orbits with moderate radius ratio, including a preliminary analysis of Earth-Mars and Earth-Venus missions.

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

KRASNITZ,A.; VENUGOPALAN,R.

The dynamics of low-x partons in the transverse plane of a high-energy nuclear collision is classical, and therefore admits a fully non-perturbative numerical treatment. The authors report results of a recent study estimating the initial energy density in the central region of a collision. Preliminary estimates of the number of gluons per unit rapidity, and the initial transverse momentum distribution of gluons, are also provided.

75 FR 22589 - Preliminary Listing of an Additional Water to Wisconsin's 2008 List of Waters Under Section 303(d...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-29

... to the presence of excessive nutrients, including phosphorus, elevated pH values, as well as the... Wisconsin does not have numeric criterian for phosphorus and WDNR did not believe that the available data..., and that the Bay was not impaired due to phosphorus. WDNR stated that it will continue to monitor...

Recent developments in large-scale structural optimization

NASA Technical Reports Server (NTRS)

Venkayya, Vipperla B.

1989-01-01

A brief discussion is given of mathematical optimization and the motivation for the development of more recent numerical search procedures. A review of recent developments and issues in multidisciplinary optimization is also presented. These developments are discussed in the context of the preliminary design of aircraft structures. A capability description of programs FASTOP, TSO, STARS, LAGRANGE, ELFINI and ASTROS is included.

Public Perceptions and Expectations of the Forensic Use of DNA: Results of a Preliminary Study

ERIC Educational Resources Information Center

Curtis, Cate

2009-01-01

The forensic use of Deoxyribonucleic Acid (DNA) is demonstrating significant success as a crime-solving tool. However, numerous concerns have been raised regarding the potential for DNA use to contravene cultural, ethical, and legal codes. In this article the expectations and level of knowledge of the New Zealand public of the DNA data-bank and…

Assessing Gains in Language Proficiency, Cross-Cultural Competence, and Regional Awareness during Study Abroad: A Preliminary Study

ERIC Educational Resources Information Center

Watson, Jeffrey R.; Siska, Peter; Wolfel, Richard L.

2013-01-01

As a critical part of the internationalization movement in college curricula, study abroad initiatives are becoming more and more popular and the need to assess their outcomes more and more evident. While numerous studies have investigated the language gain associated with study abroad, researchers are also beginning to look at potential gains in…

The Effect of Personal Values, Organizational Values, and Person-Organization Fit on Ethical Behaviors and Organizational Commitment Outcomes among Substance Abuse Counselors: A Preliminary Investigation

ERIC Educational Resources Information Center

Thomas, Tammara Petrill

2013-01-01

Numerous research studies have concluded that values drive perceptions, responses to situations, judgments, interactions among people, and behaviors. In addition, studies have found that congruence or agreement between individual values and organizational values can increase job satisfaction and commitment. Minimal research has explored the…

Voyages to Saturn

NASA Technical Reports Server (NTRS)

Morrison, D.

1982-01-01

The Voyager mission to Saturn is explained in detail. A history of Saturn observations from ancient times to the present is given. The Voyager spacecraft and their instruments are described. An overview of planetary astronomy is presented. The text is supplemented by numerous black and white and color photographs. The Saturn satellites are discussed in detail, and preliminary pictorial maps of the satellites are given.

School Students' Conceptual Patterns about Weight Gain: A Preliminary Study for Biology Teaching Focusing on Obesity

ERIC Educational Resources Information Center

Ozbas, Serap; Kilinc, Ahmet

2015-01-01

Obesity is a critical global public health issue. It leads to numerous health conditions that limit the quality and length of life, placing a huge burden on healthcare systems around the world. Scholars believe that the fight against obesity can be won only through multidisciplinary efforts. However, the literature on people's understanding of…

Numerical Analysis of Solids at Failure

DTIC Science & Technology

2011-08-20

failure analyses include the formulation of invariant finite elements for thin Kirchhoff rods, and preliminary initial studies of growth in...analysis of the failure of other structural/mechanical systems, including the finite element modeling of thin Kirchhoff rods and the constitutive...algorithm based on the connectivity graph of the underlying finite element mesh. In this setting, the discontinuities are defined by fronts propagating

Installation Restoration Program. Preliminary Assessment: 118th Tactical Airlift Wing Tennessee Air National Guard, Nashville International Airport, Nashville, Tennessee

DTIC Science & Technology

1988-12-01

disseminated silt and shale partings. The unit is medium-bedded and is characterized by numerous fossils of the brachiopod Resseralla fertilis . The... runoff from the Base is collected by the storm sewer system and discharged to McCrory Creek (Figure 6). The confluence of McCrory Creek and the Stone

Synaptic Plasticity In Mammalian Gravity Sensors: Preliminary Results From SLS-2

NASA Technical Reports Server (NTRS)

Ross, M. D.; Hargens, Alan R. (Technical Monitor)

1996-01-01

Sensory conflict is the prevalent theoretical explanation for space adaptation syndrome. This ultrastructural study tests the hypothesis that peripheral gravity sensors (maculae) play a role. Results were obtained from the medial part of utricular maculae of adult rats exposed to microgravity for 14 days, and from controls. Means and statistical significance of synapse counts were calculated using SUPERANOVA(Trademark) and Scheffe's procedure for post-hoc comparisons. Preliminary findings are from 2 sets of 100 serial sections for each dataset. Synapses were doubled numerically in type II hair cells of utricular maculae collected on day 13 inflight compared to controls (11.4 +/- 7.1 vs. 5.3 +/- 3.8; p < 0.0001). Flight mean synaptic number declined rapidly postflight and became comparable to means of controls. Synapses also increased numerically in type I cells inflight (2.4 +/- 1.6 vs. 1.7 +/- 1.0; p < 0.0341). Postflight there were no significant differences in counts. Results concerning shifts in ribbon type and distribution are also largely replicating previous findings from flight studies. Results indicate that mammalian maculae are adaptive endorgans that retain the property of synaptic plasticity into the adult stage. Macular plasticity has clinical implications for balance disorders of peripheral origin.

Development of a 3D numerical methodology for fast prediction of gun blast induced loading

NASA Astrophysics Data System (ADS)

Costa, E.; Lagasco, F.

2014-05-01

In this paper, the development of a methodology based on semi-empirical models from the literature to carry out 3D prediction of pressure loading on surfaces adjacent to a weapon system during firing is presented. This loading is consequent to the impact of the blast wave generated by the projectile exiting the muzzle bore. When exceeding a pressure threshold level, loading is potentially capable to induce unwanted damage to nearby hard structures as well as frangible panels or electronic equipment. The implemented model shows the ability to quickly predict the distribution of the blast wave parameters over three-dimensional complex geometry surfaces when the weapon design and emplacement data as well as propellant and projectile characteristics are available. Considering these capabilities, the use of the proposed methodology is envisaged as desirable in the preliminary design phase of the combat system to predict adverse effects and then enable to identify the most appropriate countermeasures. By providing a preliminary but sensitive estimate of the operative environmental loading, this numerical means represents a good alternative to more powerful, but time consuming advanced computational fluid dynamics tools, which use can, thus, be limited to the final phase of the design.

Experimental and numerical analysis of pre-compressed masonry walls in two-way-bending with second order effects

NASA Astrophysics Data System (ADS)

Milani, Gabriele; Olivito, Renato S.; Tralli, Antonio

2014-10-01

The buckling behavior of slender unreinforced masonry (URM) walls subjected to axial compression and out-of-plane lateral loads is investigated through a combined experimental and numerical homogenizedapproach. After a preliminary analysis performed on a unit cell meshed by means of elastic FEs and non-linear interfaces, macroscopic moment-curvature diagrams so obtained are implemented at a structural level, discretizing masonry by means of rigid triangular elements and non-linear interfaces. The non-linear incremental response of the structure is accounted for a specific quadratic programming routine. In parallel, a wide experimental campaign is conducted on walls in two way bending, with the double aim of both validating the numerical model and investigating the behavior of walls that may not be reduced to simple cantilevers or simply supported beams. Panels investigated are dry-joint in scale square walls simply supported at the base and on a vertical edge, exhibiting the classical Rondelet's mechanism. The results obtained are compared with those provided by the numerical model.

Supercritical flow characteristics at abrupt expansion structure

NASA Astrophysics Data System (ADS)

Lim, Jia Jun; Puay, How Tion; Zakaria, Nor Azazi

2017-10-01

When dealing with the design of a hydraulic structure, lateral expansion is often necessary for flow emerging at high velocity served as a cross-sectional transition. If the abrupt expansion structure is made to diverge rapidly, it will cause the major part of the flow fail to follow the boundaries. If the transition is too gradual, it will result in a waste of structural material. A preliminary study on the flow structure near the expansion and its relationship with flow parameter is carried out in this study. A two-dimensional depth-averaged model is developed to simulate the supercritical flow at the abrupt expansion structure. Constrained Interpolation Profile (CIP) scheme (which is of third order accuracy) is adopted in the numerical model. Results show that the flow structure and flow characteristics at the abrupt expansion can be reproduced numerically. The validation of numerical result is done against analytical studies. The result from numerical simulation showed good agreement with the analytical solution.

The Viking biological investigation - Preliminary results

NASA Technical Reports Server (NTRS)

Klein, H. P.; Oyama, V. I.; Berdahl, B. J.; Horowitz, N. H.; Hobby, G. L.; Levin, G. V.; Straat, P. A.; Lederberg, J.; Rich, A.; Hubbard, J. S.

1976-01-01

A preliminary progress report is presented for the Viking biological investigation through its first month. The carbon assimilation, gas exchange, and labeled release experiments are described in detail, and the chronology of the experiments is outlined. For the first experiment, it is found that a small amount of gas was converted into organic material in one sample and that heat treatment of a duplicate sample prevented such conversion. In the second experiment, a substantial amount of O2 was detected along with significant increases in CO2 and small changes in N2. In the third experiment, a significant amount of radioactive gas was evolved from one sample, but not from a duplicate heat-treated sample. Possible biological and nonbiological interpretations are considered for these results. It is concluded that while the experiments provide clear evidence for the occurrence of chemical reactions and while the results do not violate any prima facie criteria for biological processes, a definitive answer cannot yet be given to the question of whether life exists on Mars.

A preliminary discussion of gravitational physics experiments for the Spacelab era

NASA Technical Reports Server (NTRS)

Decher, R.; Winkler, C. G.

1976-01-01

An overview of past, present, and proposed future experiments in gravitational physics is given. These experiments are concerned with the measurement of relativistic gravity effects to test theories of gravitation. Certain experiments which could be performed on shuttle and Spacelab missions and the potential of Spacelab for gravitation physics research are discussed.

Shock Experiments on Basalt - Ferric Sulfate Mixes at 21 GPa & 49 GPa and their Relevance to Martian Meteorite Impact Glasses

NASA Technical Reports Server (NTRS)

Rao, M. N.; Ross, D. K.; See, T. H.; Nyquist, L. E.; Sutton, S.; Asimow, P.

2013-01-01

Large abundance of Martian atmospheric gases and neutron-induced isotopic excesses as well as Rb-Sr isotopic variations determined in some impact glasses in basaltic shergottites (e.g., Shergotty #DBS, Zagami #H1 and EET79001 #27, #8 and #104) provide definitive evidence for the occurrence of a Martian regolith component in their constituent mineral assemblages. Some of these glass-es, known as gas-rich impact-melts (GRIM), contain numerous micron-sized iron sulfide blebs along with minor amounts of iron sulfate particulates. As these GRIM glasses contain a Martian regolith component and as iron sulfates (but not sulfides) are found to occur abundantly on the Mars surface, we suggested that the sulfide blebs in GRIMs were likely generated by shock-reduction of the parental iron sulfate bearing regolith material that had been incorporated into the cavities/crevices of basaltic host rock prior to the impact event on Mars. To test whether the sulfates could be reduced to sulfides by impact shock, we carried out laboratory shock experiments on a basalt plus ferric sulfate mixture at 49 GPa at the Caltech Shock Wave Laboratory and at 21 GPa at Johnson Space Center (JSC) Experimental Impact Laboratory. The experimental details and the preliminary results for the Caltech 49 GPa experiment were presented at LPSC last year. Here, we report the results for the 21 GPa experiment at JSC and compare these results to obtain further insight into the mechanism of the bleb formation in the GRIM glasses.

Preliminary experiments to quantify liquid movement under mimetic vocal fold vibrational forces.

PubMed

Titze, Ingo R; Klemuk, Sarah; Lu, Xiaoying

2014-07-01

Hydration of vocal fold tissues is essential for self-sustained oscillation. Normal regulatory processes of liquid transport to and from the vocal folds would be expected through the autonomic systems, but the possibility exists that liquid movement may occur locally due to vibrational pressures. Such movement may cause regions of lower or higher concentrations of liquid viscosity and therewith changes in phonation threshold pressure. Hyaluronic acid, a glycosaminoglycan that attracts large quantities of free water, may be a key molecule for transporting or localizing liquids. Some preliminary experiments are reported in which attempts were made to move low-concentration HA liquids with vibration. None of the experiments was conclusive, but collectively they lay some groundwork for future explorations.

Mathematical Methods for Physics and Engineering Third Edition Paperback Set

NASA Astrophysics Data System (ADS)

Riley, Ken F.; Hobson, Mike P.; Bence, Stephen J.

2006-06-01

Prefaces; 1. Preliminary algebra; 2. Preliminary calculus; 3. Complex numbers and hyperbolic functions; 4. Series and limits; 5. Partial differentiation; 6. Multiple integrals; 7. Vector algebra; 8. Matrices and vector spaces; 9. Normal modes; 10. Vector calculus; 11. Line, surface and volume integrals; 12. Fourier series; 13. Integral transforms; 14. First-order ordinary differential equations; 15. Higher-order ordinary differential equations; 16. Series solutions of ordinary differential equations; 17. Eigenfunction methods for differential equations; 18. Special functions; 19. Quantum operators; 20. Partial differential equations: general and particular; 21. Partial differential equations: separation of variables; 22. Calculus of variations; 23. Integral equations; 24. Complex variables; 25. Application of complex variables; 26. Tensors; 27. Numerical methods; 28. Group theory; 29. Representation theory; 30. Probability; 31. Statistics; Index.

Velocity Measurements in Nasal Cavities by Means of Stereoscopic Piv - Preliminary Tests

NASA Astrophysics Data System (ADS)

Cozzi, Fabio; Felisati, Giovanni; Quadrio, Maurizio

2017-08-01

The prediction of detailed flow patterns in human nasal cavities using computational fluid dynamics (CFD) can provide essential information on the potential relationship between patient-specific geometrical characteristics of the nasal anatomy and health problems, and ultimately led to improved surgery. The complex flow structure and the intricate geometry of the nasal cavities make achieving such goals a challenge for CFD specialists. The need for experimental data to validate and improve the numerical simulations is particularly crucial. To this aim an experimental set-up based on Stereo PIV and a silicon phantom of nasal cavities have been designed and realized at Politecnico di Milano. This work describes the main features and challenges of the set-up along with some preliminary results.

Diagnostic analysis of observed and numerically simulated cloud and precipitation structures during pre-ERICA

NASA Technical Reports Server (NTRS)

Perkey, Donald J.; Doty, Kevin G.; Robertson, Franklin R.

1989-01-01

A preliminary 140-km simulation of a rapid cyclogenesis, using the Limited Area Mesoscale Prediction System (LAMPS) is discussed. A three-dimensional version of LAMPS used in the simulation is described, along with a trajectory model utilizing the three-hourly output history files from the LAMPS model. Preliminary integrations of the LAMPS code as well as passive microwave digital data from SSM/I aboard the DMSP satellite are used for exploring the evolving baroclinic structure and moisture field of the cyclone event. A trajectory analysis of the model histories reveals a significant role for preconditioning of the low-level upstream air, which is then drawn into the ascending warm conveyor belt ahead of the storm.

Numerical Optimization Using Computer Experiments

NASA Technical Reports Server (NTRS)

Trosset, Michael W.; Torczon, Virginia

1997-01-01

Engineering design optimization often gives rise to problems in which expensive objective functions are minimized by derivative-free methods. We propose a method for solving such problems that synthesizes ideas from the numerical optimization and computer experiment literatures. Our approach relies on kriging known function values to construct a sequence of surrogate models of the objective function that are used to guide a grid search for a minimizer. Results from numerical experiments on a standard test problem are presented.

Preliminary Report of NRC Twin Otter Operations in the 1997 Southern Great Plains Experiment

NASA Technical Reports Server (NTRS)

MacPherson, J. Ian

1997-01-01

From June 18 to July 17, 1997, the NRC Twin Otter atmospheric research aircraft was operated from Oklahoma City, U.S.A., in the Southern Great Plains 1997 (SGP97) Hydrology Experiment. The primary role of the aircraft was to measure the vertical fluxes of sensible and latent heat, CO2, ozone and momentum in the atmospheric boundary layer, along with supporting meteorological and radiometric data. Approximately 400 flux runs and 100 soundings were flown in 27 project flights over rural areas near Oklahoma City. This preliminary report documents the flight program, lists the instrumentation aboard the aircraft, and presents a summary of run-averaged data from each flux run. These data are from the in-field analysis and must be considered preliminary. A re-analysis incorporating updated calibrations is planned for the fall of 1997 followed by a more comprehensive technical report.

Chemical Analysis of the Moon at the Surveyor VII Landing Site: Preliminary Results.

PubMed

Turkevich, A L; Franzgrote, E J; Patterson, J H

1968-10-04

The alpha-scattering experiment aboard Surveyor VII has provided a chemical analysis of the moon in the area of the crater Tycho. The preliminary results indicate a chemical composition similar to that already found at two mare sites, but with a lower concentration of elements of the iron group (titanium through copper).

Preliminary Analysis of Fluctuations in the Received Uplink-Beacon-Power Data Obtained From the GOLD Experiments

NASA Technical Reports Server (NTRS)

Jeganathan, M.; Wilson, K. E.; Lesh, J. R.

1996-01-01

Uplink data from recent free-space optical communication experiments carried out between the Table Mountain Facility and the Japanese Engineering Test Satellite are used to study fluctuations caused by beam propagation through the atmosphere. The influence of atmospheric scintillation, beam wander and jitter, and multiple uplink beams on the statistics of power received by the satellite is analyzed and compared to experimental data. Preliminary analysis indicates the received signal obeys an approximate lognormal distribution, as predicted by the weak-turbulence model, but further characterization of other sources of fluctuations is necessary for accurate link predictions.

Preliminary analysis of fluctuations in the received uplink-beacon-power data obtained from the GOLD experiments

NASA Technical Reports Server (NTRS)

Jeganathan, M.; Wilson, K. E.; Lesh, J. R.

1996-01-01

Uplink data from recent free-space optical communication experiments carried out between the Table Mountain Facility and the Japanese Engineering Test Satellite are used to study fluctuations caused by beam propagation through the atmosphere. The influence of atmospheric scintillation, beam wander and jitter, and multiple uplink beams on the statistics of power received by the satellite is analyzed and compared to experimental data. Preliminary analysis indicates the received signal obeys an approximate lognormal distribution, as predicted by the weak-turbulence model, but further characterization of other sources of fluctuations is necessary for accurate link predictions.

The Trier Social Stress Test and the Trier Social Stress Test for groups: Qualitative investigations

PubMed Central

Marqueste, Tanguy; Mascret, Nicolas

2018-01-01

The Trier Social Stress Test (TSST) and its version for groups (TSST-G) are the gold standard for inducing acute psychosocial stress in human experimental settings and have been used in numerous studies since the early 1990s. The TSST and the TSST-G lead to effects on different physiological and psychological markers, such as salivary cortisol, anxiety, and emotional states. These effects were assessed with quantitative methods comparing pre-test and post-test measures with statistical analyses. But to date, no qualitative analyses have been conducted to examine the meaningful experience of participants during the TSST and the TSST-G. This study is the first to conduct qualitative investigations to further clarify the stressful experience of participants confronted with these procedures. Preliminary results showed as expected that the TSST and the TSST-G effectively induced psychosocial stress, with cortisol levels, cognitive anxiety, somatic anxiety, and arousal increases, and with pleasure and dominance decreases. At the qualitative level, the results evidenced that the two theoretically stressful components of the TSST and the TSST-G, namely social-evaluative threat and uncontrollability, were experienced as stress-inducing by the participants. Two case studies confirmed these findings. But the results also showed on one hand that psychosocial stress is a dynamic phenomenon, with important fluctuations throughout the tasks (mainly for the TSST-G); and on the other hand that despite the similar physiological and psychological responses between the TSST and the TSST-G evidenced by the literature, the experience of the participants was both similar and specific. Use of a qualitative method allowed us to provide a complementary point of view to understand the meaningful experience of participants during these stressful procedures, apprehending the dynamic of the subjective stress experience without disrupting it. PMID:29641572

The Trier Social Stress Test and the Trier Social Stress Test for groups: Qualitative investigations.

PubMed

Vors, Olivier; Marqueste, Tanguy; Mascret, Nicolas

2018-01-01

The Trier Social Stress Test (TSST) and its version for groups (TSST-G) are the gold standard for inducing acute psychosocial stress in human experimental settings and have been used in numerous studies since the early 1990s. The TSST and the TSST-G lead to effects on different physiological and psychological markers, such as salivary cortisol, anxiety, and emotional states. These effects were assessed with quantitative methods comparing pre-test and post-test measures with statistical analyses. But to date, no qualitative analyses have been conducted to examine the meaningful experience of participants during the TSST and the TSST-G. This study is the first to conduct qualitative investigations to further clarify the stressful experience of participants confronted with these procedures. Preliminary results showed as expected that the TSST and the TSST-G effectively induced psychosocial stress, with cortisol levels, cognitive anxiety, somatic anxiety, and arousal increases, and with pleasure and dominance decreases. At the qualitative level, the results evidenced that the two theoretically stressful components of the TSST and the TSST-G, namely social-evaluative threat and uncontrollability, were experienced as stress-inducing by the participants. Two case studies confirmed these findings. But the results also showed on one hand that psychosocial stress is a dynamic phenomenon, with important fluctuations throughout the tasks (mainly for the TSST-G); and on the other hand that despite the similar physiological and psychological responses between the TSST and the TSST-G evidenced by the literature, the experience of the participants was both similar and specific. Use of a qualitative method allowed us to provide a complementary point of view to understand the meaningful experience of participants during these stressful procedures, apprehending the dynamic of the subjective stress experience without disrupting it.

Design, construction, and testing of the direct absorption receiver panel research experiment

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

Chavez, J.M.; Rush, E.E.; Matthews, C.W.

1990-01-01

A panel research experiment (PRE) was designed, built, and tested as a scaled-down model of a direct absorption receiver (DAR). The PRE is a 3-MW{sub t}DAR experiment that will allow flow testing with molten nitrate salt and provide a test bed for DAR testing with actual solar heating. In a solar central receiver system DAR, the heat absorbing fluid (a blackened molten nitrate salt) flows in a thin film down a vertical panel (rather than through tubes as in conventional receiver designs) and absorbs the concentrated solar flux directly. The ability of the flowing salt film to absorb flux directly.more » The ability of the flowing salt film to absorb the incident solar flux depends on the panel design, hydraulic and thermal fluid flow characteristics, and fluid blackener properties. Testing of the PRE is being conducted to demonstrate the engineering feasibility of the DAR concept. The DAR concept is being investigated because it offers numerous potential performance and economic advantages for production of electricity when compared to other solar receiver designs. The PRE utilized a 1-m wide by 6-m long absorber panel. The salt flow tests are being used to investigate component performance, panel deformations, and fluid stability. Salt flow testing has demonstrated that all the DAR components work as designed and that there are fluid stability issues that need to be addressed. Future solar testing will include steady-state and transient experiments, thermal loss measurements, responses to severe flux and temperature gradients and determination of peak flux capability, and optimized operation. In this paper, we describe the design, construction, and some preliminary flow test results of the Panel Research Experiment. 11 refs., 8 figs., 2 tabs.« less

Motivation for proposed experimentation in the realm of accelerated E. M. systems: A preliminary design for an experiment

NASA Technical Reports Server (NTRS)

Post, E. J.

1970-01-01

An experiment, designed to determine the difference between fields-magnetic and electric-surrounding a uniformly moving charge as contrasted with the fields surrounding an accelerated charge, is presented. A thought experiment is presented to illustrate the process.

General characteristics of preliminary data processing in the Copernicus experiment

NASA Technical Reports Server (NTRS)

Ziolkovski, K.; Kossatski, K.

1975-01-01

Data from the 'Copernicus' experiment is processed in four stages: setting up of basic arrays, data calibration, graphical display of results, and assignment of results to navigation parameters. Each stage is briefly discussed.

Modeling and new equipment definition for the vibration isolation box equipment system

NASA Technical Reports Server (NTRS)

Sani, Robert L.

1993-01-01

Our MSAD-funded research project is to provide numerical modeling support for the VIBES (Vibration Isolation Box Experiment System) which is an IML2 flight experiment being built by the Japanese research team of Dr. H. Azuma of the Japanese National Aerospace Laboratory. During this reporting period, the following have been accomplished: A semi-consistent mass finite element projection algorithm for 2D and 3D Boussinesq flows has been implemented on Sun, HP And Cray Platforms. The algorithm has better phase speed accuracy than similar finite difference or lumped mass finite element algorithms, an attribute which is essential for addressing realistic g-jitter effects as well as convectively-dominated transient systems. The projection algorithm has been benchmarked against solutions generated via the commercial code FIDAP. The algorithm appears to be accurate as well as computationally efficient. Optimization and potential parallelization studies are underway. Our implementation to date has focused on execution of the basic algorithm with at most a concern for vectorization. The initial time-varying gravity Boussinesq flow simulation is being set up. The mesh is being designed and the input file is being generated. Some preliminary 'small mesh' cases will be attempted on our HP9000/735 while our request to MSAD for supercomputing resources is being addressed. The Japanese research team for VIBES was visited, the current set up and status of the physical experiment was obtained and ongoing E-Mail communication link was established.

Effect of Residual Noncondensables on Pressurization and Pressure Control of a Zero-Boil-Off Tank in Microgravity

NASA Technical Reports Server (NTRS)

Kassemi, Mohammad; Hylton, Sonya; Kartizova, Olga

2013-01-01

The Zero-Boil-Off Tank (ZBOT) Experiment is a small-scale experiment that uses a transparent ventless Dewar and a transparent simulant phase-change fluid to study sealed tank pressurization and pressure control with applications to on-surface and in-orbit storage of propellant cryogens. The experiment will be carried out under microgravity conditions aboard the International Space Station in the 2014 timeframe. This paper presents preliminary results from ZBOT's ground-based research that focuses on the effects of residual noncondensable gases in the ullage on both pressurization and pressure reduction trends in the sealed Dewar. Tank pressurization is accomplished through heating of the test cell wall in the wetted and un-wetted regions simultaneously or separately. Pressure control is established through mixing and destratification of the bulk liquid using a temperature controlled forced jet flow with different degrees of liquid jet subcooling. A Two-Dimensional axisymmetric two-phase CFD model for tank pressurization and pressure control is also presented. Numerical prediction of the model are compared to experimental 1g results to both validate the model and also indicate the effect of the noncondensable gas on evolution of pressure and temperature distributions in the ullage during pressurization and pressure control. Microgravity simulations case studies are also performed using the validated model to underscore and delineate the profound effect of the noncondensables on condensation rates and interfacial temperature distributions with serious implications for tank pressure control in reduced gravity.

Broadband network on-line data acquisition system with web based interface for control and basic analysis

NASA Astrophysics Data System (ADS)

Polkowski, Marcin; Grad, Marek

2016-04-01

Passive seismic experiment "13BB Star" is operated since mid 2013 in northern Poland and consists of 13 broadband seismic stations. One of the elements of this experiment is dedicated on-line data acquisition system comprised of both client (station) side and server side modules with web based interface that allows monitoring of network status and provides tools for preliminary data analysis. Station side is controlled by ARM Linux board that is programmed to maintain 3G/EDGE internet connection, receive data from digitizer, send data do central server among with additional auxiliary parameters like temperatures, voltages and electric current measurements. Station side is controlled by set of easy to install PHP scripts. Data is transmitted securely over SSH protocol to central server. Central server is a dedicated Linux based machine. Its duty is receiving and processing all data from all stations including auxiliary parameters. Server side software is written in PHP and Python. Additionally, it allows remote station configuration and provides web based interface for user friendly interaction. All collected data can be displayed for each day and station. It also allows manual creation of event oriented plots with different filtering abilities and provides numerous status and statistic information. Our solution is very flexible and easy to modify. In this presentation we would like to share our solution and experience. National Science Centre Poland provided financial support for this work via NCN grant DEC-2011/02/A/ST10/00284.

Rapid and reliable healing of critical size bone defects with genetically modified sheep muscle.

PubMed

Liu, F; Ferreira, E; Porter, R M; Glatt, V; Schinhan, M; Shen, Z; Randolph, M A; Kirker-Head, C A; Wehling, C; Vrahas, M S; Evans, C H; Wells, J W

2015-09-21

Large segmental defects in bone fail to heal and remain a clinical problem. Muscle is highly osteogenic, and preliminary data suggest that autologous muscle tissue expressing bone morphogenetic protein-2 (BMP-2) efficiently heals critical size defects in rats. Translation into possible human clinical trials requires, inter alia, demonstration of efficacy in a large animal, such as the sheep. Scale-up is fraught with numerous biological, anatomical, mechanical and structural variables, which cannot be addressed systematically because of cost and other practical issues. For this reason, we developed a translational model enabling us to isolate the biological question of whether sheep muscle, transduced with adenovirus expressing BMP-2, could heal critical size defects in vivo. Initial experiments in athymic rats noted strong healing in only about one-third of animals because of unexpected immune responses to sheep antigens. For this reason, subsequent experiments were performed with Fischer rats under transient immunosuppression. Such experiments confirmed remarkably rapid and reliable healing of the defects in all rats, with bridging by 2 weeks and remodelling as early as 3-4 weeks, despite BMP-2 production only in nanogram quantities and persisting for only 1-3 weeks. By 8 weeks the healed defects contained well-organised new bone with advanced neo-cortication and abundant marrow. Bone mineral content and mechanical strength were close to normal values. These data demonstrate the utility of this model when adapting this technology for bone healing in sheep, as a prelude to human clinical trials.

Diverse Seismic Imaging Created by the Seismic Explosion Experiment of the TAIGER Project

NASA Astrophysics Data System (ADS)

Wang, C.; Okaya, D.; Wu, F.; Yen, H.; Huang, B.; Liang, W.

2008-12-01

The TAIGER (TAiwan Integrated GEodynamics Research) project which examines the Taiwan orogeny includes five experiments: natural earthquake recording, man-made explosion recording, Magnetotelluic imaging, marine MCS and sea-land shooting, and deformation evolution modeling. During Feb-Mar 2008, the explosion experiment was carried out. Ten sources with 500~3000kg dynamite were detonated along two transects across northern and southern Taiwan. Over 600 PASSCAL Texans and 40 R-130 instruments record the signals over 100~300 km range. Additional arrays with 100 seismometers were deployed to collect north-south line and fan shoot data for 3D imaging. Furthermore, there are 9 ocean bottom seismometers (OBS) in the Taiwan Strait and two lines with 20 seismometers deployed on the mainland China side. A large volume of qualified data has been created. Except explosion signals, numerous local and regional earthquakes were also recorded even by the Texan instruments. The rich earthquake-explosion dataset now exists at the Institute of Earth Sciences, Academia Sinica operated by the Taiwan Earthquake Center (TEC). Preliminary examination of the data reveal crustal Pg, PmP, Pn and intermediate crustal reflection phases within the transect profiles and in the 3D cross-arrays. These data provide direct seismic imaging of the continental Moho under Taiwan and the sharp Moho root configuration associated with mountain building. Seismic tomography and raytrace methods reveal velocity structure consistent with convergence and vertical exhumation of the Central Ranges.

Symbolic Estrangement: Evidence against a Strong Association between Numerical Symbols and the Quantities They Represent

ERIC Educational Resources Information Center

Lyons, Ian M.; Ansari, Daniel; Beilock, Sian L.

2012-01-01

Are numerals estranged from a sense of the actual quantities they represent? We demonstrate that, irrespective of numerical size or distance, direct comparison of the relative quantities represented by symbolic and nonsymbolic formats leads to performance markedly worse than when comparing 2 nonsymbolic quantities (Experiment 1). Experiment 2…

Near-Death Experiences and the "Fantasy-Prone" Personality: Preliminary Findings.

ERIC Educational Resources Information Center

Council, James R.; Greyson, Bruce

Near-death experiences (NDEs) are subjective experiences at the threshold of death which can include strong positive affect, dissociation from the physical body, and paranormal/transcendental phenomena. Empirical investigation of NDEs has typically relied upon retrospective reports and personality studies of individuals who have come close to…

Experiment module concepts study. Volume 5 book 1, appendix A: Shuttle only task

NASA Technical Reports Server (NTRS)

1970-01-01

Results of a preliminary investigation of the effect on the candidate experiment program implementation of experiment module operations in the absence of an orbiting space station and with the availability of the space shuttle orbiter vehicle only are presented. The fundamental hardware elements for shuttle-only operation of the program are: (1) integrated common experiment modules CM-1, CM-3, and CM-4, together with the propulsion slice; (2) support modules capable of supplying on-orbit crew life support, power, data management, and other services normally provided by a space station; (3) dormancy kits to enable normally attached modules to remain in orbit while shuttle returns to earth; and (4) shuttle orbiter. Preliminary cost estimates for 30 day on-orbit and 5 day on-orbit capabilities for a four year implementation period are $4.2 billion and $2.1 billion, respectively.

Preliminary experiments on the reduction of the uranyl ion to uraninite by carbonaceous substances

USGS Publications Warehouse

Breger, Irving A.; Moore, Richard T.

1955-01-01

An aqueous solution of uranyl sulfate containing a suspension of subbituminous coal has been heated at 210 C for three days. Examination of the coal at the end of the experiment showed it to contain 31.8 percent uranium recognizable as uraninite by a sharp, strong X-ray diffraction pattern. A similar experiment with degraded spruce wood also led to the formation of uraninite but in lesser quantity and with broader lines in the X-ray diffraction pattern. The ability of coal or wood to reduce the uranyl ion is a critical factor in the correlation of studies of uraniferous coals containing the uranyl ion with studies of uraninite-bearing coalified wood from the Colorado Plateau. Although these results are based an preliminary experiments, they are extremely important geochemically and warrant the development of the series of controlled studies that are proposed.

A preliminary study of preservative retention and penetration in ACQ-treated timbers using near infrared spectroscopy

Treesearch

Chi-Leung So; Thomas L. Eberhardt; Stan T. Lebow; Leslie H. Groom

2006-01-01

Near infrared (NIR) spectroscopy has been previously used in our laboratory to predict copper, chromium, and arsenic levels in samples of chromated copper arsenate (CCA)-treated wood. In the present study, we utilized our custom-made NIR scanning system, NIRVANA (near infrared visual and automated numerical analysis), to scan cross sections of ACQ (alkaline copper quat...

Preliminary Study of Turbulence for a Lobed Body in Hypersonic Flight

DTIC Science & Technology

2013-02-22

physics. Modest improvements in numerical algorithms, particularly those for solving partial differential equations ( PDEs ), can now be fully...dramatically.[7] In slower speed flow fields, this energy is absorbed mostly in molecular translational and rotational modes, but for hypersonic...REFERENCES 1. Génin, F., Fryxell, B. and Menon, S., “Simulation of Detonation Propagation in Turbulent Gas- Solid Reactive Mixtures”, 41 st

Stability of compressible Taylor-Couette flow

NASA Technical Reports Server (NTRS)

Kao, K.; Chow, C.

1992-01-01

The objectives of this paper are to: (1) develop both analytical and numerical tools that can be used to predict the onset of instability and subsequently to simulate the transition process by which the originally laminar flow evolves into a turbulent flow; and (2) conduct the preliminary investigations with the purpose of understanding the mechanisms of the vortical structures of the compressible flow between tow concentric cylinders.

9-D polarized proton transport in the MEIC figure 8 collider ring - first steps

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

Meot, F.; Morozov, V. S.

2015-05-03

Spin tracking studies in the MEIC figure-8 collider ion ring are presented, based on a very preliminary design of the lattice. They provide numerical illustrations of some of the aspects of the figure-8 concept, including spin-rotator based spin control, and lay out the path towards a complete spin tracking simulation of a figure-8 ring.

9-D polarized proton transport in the MEIC figure-8 collider ring: first steps

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

Meot, F.; Thomas Jefferson National Accelerator Facility; Morozov, V. S.

2014-10-24

Spin tracking studies in the MEIC figure-8 collider ion ring are presented, based on a very preliminary design of the lattice. They provide numerical illustrations of some of the aspects of the figure-8 concept, including spin-rotator based spin control, and lay out the path towards a complete spin tracking simulation of a figure-8 ring.

Designing Shelter in New Buildings. A Manual for Architects on the Preliminary Designing of Shielding from Fallout Gamma Radiation in Normally Functioning Spaces in New Buildings.

ERIC Educational Resources Information Center

Knott, Albert

Analysis of radiation fallout prevention factors in new construction is presented with emphasis on architectural shielding principles. Numerous diagrams and charts illustrate--(1) radiation and fallout properties, (2) building protection principles, (3) details and planning suggestions, and (4) tabular data interpretation. A series of charts is…

Preliminary design of an auxiliary power unit for the space shuttle. Volume 3: Details of system analysis, engineering, and design for selected system

NASA Technical Reports Server (NTRS)

Hamilton, M. L.; Burriss, W. L.

1972-01-01

Numerous candidate APU concepts, each meeting the space shuttle APU problem statement are considered. Evaluation of these concepts indicates that the optimum concept is a hydrogen-oxygen APU incorporating a recuperator to utilize the exhaust energy and using the cycle hydrogen flow as a means of cooling the component heat loads.

Sphingoid esters from the molecular distillation of squid oil: A preliminary bioactivity determination.

PubMed

Saliu, Francesco; Longhin, Eleonora; Salanti, Anika; Degano, Ilaria; Della Pergola, Roberto

2016-06-15

A mixture of sphingoid esters was isolated (1.4% w/w) from the molecular distillation of crude squid visceral oil. A preliminary investigation on the bioactivity profile and toxic potential of this residue was carried out by in vitro experiments. No cytotoxicity and a moderate lipase inhibition activity were highlighted. Copyright © 2016 Elsevier Ltd. All rights reserved.

The structure and rainfall features of Tropical Cyclone Rammasun (2002)

NASA Astrophysics Data System (ADS)

Ma, Leiming; Duan, Yihong; Zhu, Yongti

2004-12-01

Tropical Rainfall Measuring Mission (TRMM) data [TRMM Microwave Imager/Precipitation Radar/Visible and Infrared Scanner (TMI/PR/VIRS)] and a numerical model are used to investigate the structure and rainfall features of Tropical Cyclone (TC) Rammasun (2002). Based on the analysis of TRMM data, which are diagnosed together with NCEP/AVN [Aviation (global model)] analysis data, some typical features of TC structure and rainfall are preliminary discovered. Since the limitations of TRMM data are considered for their time resolution and coverage, the world observed by TRMM at several moments cannot be taken as the representation of the whole period of the TC lifecycle, therefore the picture should be reproduced by a numerical model of high quality. To better understand the structure and rainfall features of TC Rammasun, a numerical simulation is carried out with mesoscale model MM5 in which the validations have been made with the data of TRMM and NCEP/AVN analysis.

Numerical investigation of perforated polymer microcantilever sensor for contractile behavior of cardiomyocytes

NASA Astrophysics Data System (ADS)

Khoa Nguyen, Trieu; Lee, Dong-Weon; Lee, Bong-Kee

2017-06-01

In this study, a numerical investigation of microcantilever sensors for detecting the contractile behavior of cardiomyocytes (CMs) was performed. Recently, a novel surface-patterned perforated SU-8 microcantilever sensor has been developed for the preliminary screening of cardiac toxicity. From the contractile motion of the CMs cultured on the microcantilever surface, a macroscopic bending of the microcantilever was obtained, which is considered to reflect a physiological change. As a continuation of the previous research, a novel numerical method based on a surface traction model was proposed and verified to further understand the bending behavior of the microcantilevers. Effects of various factors, including surface traction magnitude, focal area of CMs, and stiffness of microcantilever, on the bending displacement were investigated. From static and transient analyses, the focal area was found to be the most crucial factor. In addition, the current result can provide a design guideline for various micromechanical devices based on the same principle.

Quantitative Rainbow Schlieren Deflectometry as a Temperature Diagnostic for Spherical Flames

NASA Technical Reports Server (NTRS)

Feikema, Douglas A.

2004-01-01

Numerical analysis and experimental results are presented to define a method for quantitatively measuring the temperature distribution of a spherical diffusion flame using Rainbow Schlieren Deflectometry in microgravity. First, a numerical analysis is completed to show the method can suitably determine temperature in the presence of spatially varying species composition. Also, a numerical forward-backward inversion calculation is presented to illustrate the types of calculations and deflections to be encountered. Lastly, a normal gravity demonstration of temperature measurement in an axisymmetric laminar, diffusion flame using Rainbow Schlieren deflectometry is presented. The method employed in this paper illustrates the necessary steps for the preliminary design of a Schlieren system. The largest deflections for the normal gravity flame considered in this paper are 7.4 x 10(-4) radians which can be accurately measured with 2 meter focal length collimating and decollimating optics. The experimental uncertainty of deflection is less than 5 x 10(-5) radians.

On numerical model of one-dimensional time-dependent gas flows through bed of encapsulated phase change material

NASA Astrophysics Data System (ADS)

Lutsenko, N. A.; Fetsov, S. S.

2017-10-01

Mathematical model and numerical method are proposed for investigating the one-dimensional time-dependent gas flows through a packed bed of encapsulated Phase Change Material (PCM). The model is based on the assumption of interacting interpenetrating continua and includes equations of state, continuity, momentum conservation and energy for PCM and gas. The advantage of the method is that it does not require predicting the location of phase transition zone and can define it automatically as in a usual shock-capturing method. One of the applications of the developed numerical model is the simulation of novel Adiabatic Compressed Air Energy Storage system (A-CAES) with Thermal Energy Storage subsystem (TES) based on using the encapsulated PCM in packed bed. Preliminary test calculations give hope that the method can be effectively applied in the future for modelling the charge and discharge processes in such TES with PCM.

Conjugate gradient determination of optimal plane changes for a class of three-impulse transfers between noncoplanar circular orbits

NASA Technical Reports Server (NTRS)

Burrows, R. R.

1972-01-01

A particular type of three-impulse transfer between two circular orbits is analyzed. The possibility of three plane changes is recognized, and the problem is to optimally distribute these plane changes to minimize the sum of the individual impulses. Numerical difficulties and their solution are discussed. Numerical results obtained from a conjugate gradient technique are presented for both the case where the individual plane changes are unconstrained and for the case where they are constrained. Possibly not unexpectedly, multiple minima are found. The techniques presented could be extended to the finite burn case, but primarily the contents are addressed to preliminary mission design and vehicle sizing.

Theories and applications of second-order correlation of longitudinal velocity increments at three points in isotropic turbulence

NASA Astrophysics Data System (ADS)

Wu, J. Z.; Fang, L.; Shao, L.; Lu, L. P.

2018-06-01

In order to introduce new physics to traditional two-point correlations, we define the second-order correlation of longitudinal velocity increments at three points and obtain the analytical expressions in isotropic turbulence. By introducing the Kolmogorov 4/5 law, this three-point correlation explicitly contains velocity second- and third-order moments, which correspond to energy and energy transfer respectively. The combination of them then shows additional information of non-equilibrium turbulence by comparing to two-point correlations. Moreover, this three-point correlation shows the underlying inconsistency between numerical interpolation and three-point scaling law in numerical calculations, and inspires a preliminary model to correct this problem in isotropic turbulence.

Numerical model of solar dynamic radiator for parametric analysis

NASA Technical Reports Server (NTRS)

Rhatigan, Jennifer L.

1989-01-01

Growth power requirements for Space Station Freedom will be met through addition of 25 kW solar dynamic (SD) power modules. Extensive thermal and power cycle modeling capabilities have been developed which are powerful tools in Station design and analysis, but which prove cumbersome and costly for simple component preliminary design studies. In order to aid in refining the SD radiator to the mature design stage, a simple and flexible numerical model was developed. The model simulates heat transfer and fluid flow performance of the radiator and calculates area mass and impact survivability for many combinations of flow tube and panel configurations, fluid and material properties, and environmental and cycle variations.

Very high numerical aperture light transmitting device

DOEpatents

Allison, Stephen W.; Boatner, Lynn A.; Sales, Brian C.

1998-01-01

A new light-transmitting device using a SCIN glass core and a novel calcium sodium cladding has been developed. The very high index of refraction, radiation hardness, similar solubility for rare earths and similar melt and viscosity characteristics of core and cladding materials makes them attractive for several applications such as high-numerical-aperture optical fibers and specialty lenses. Optical fibers up to 60 m in length have been drawn, and several simple lenses have been designed, ground, and polished. Preliminary results on the ability to directly cast optical components of lead-indium phosphate glass are also discussed as well as the suitability of these glasses as a host medium for rare-earth ion lasers and amplifiers.

Mathematical and Numerical Aspects of the Adaptive Fast Multipole Poisson-Boltzmann Solver

DOE PAGES

Zhang, Bo; Lu, Benzhuo; Cheng, Xiaolin; ...

2013-01-01

This paper summarizes the mathematical and numerical theories and computational elements of the adaptive fast multipole Poisson-Boltzmann (AFMPB) solver. We introduce and discuss the following components in order: the Poisson-Boltzmann model, boundary integral equation reformulation, surface mesh generation, the nodepatch discretization approach, Krylov iterative methods, the new version of fast multipole methods (FMMs), and a dynamic prioritization technique for scheduling parallel operations. For each component, we also remark on feasible approaches for further improvements in efficiency, accuracy and applicability of the AFMPB solver to large-scale long-time molecular dynamics simulations. Lastly, the potential of the solver is demonstrated with preliminary numericalmore » results.« less

MOCCA code for star cluster simulation: comparison with optical observations using COCOA

NASA Astrophysics Data System (ADS)

Askar, Abbas; Giersz, Mirek; Pych, Wojciech; Olech, Arkadiusz; Hypki, Arkadiusz

2016-02-01

We introduce and present preliminary results from COCOA (Cluster simulatiOn Comparison with ObservAtions) code for a star cluster after 12 Gyr of evolution simulated using the MOCCA code. The COCOA code is being developed to quickly compare results of numerical simulations of star clusters with observational data. We use COCOA to obtain parameters of the projected cluster model. For comparison, a FITS file of the projected cluster was provided to observers so that they could use their observational methods and techniques to obtain cluster parameters. The results show that the similarity of cluster parameters obtained through numerical simulations and observations depends significantly on the quality of observational data and photometric accuracy.

Large-eddy simulation of a backward facing step flow using a least-squares spectral element method

NASA Technical Reports Server (NTRS)

Chan, Daniel C.; Mittal, Rajat

1996-01-01

We report preliminary results obtained from the large eddy simulation of a backward facing step at a Reynolds number of 5100. The numerical platform is based on a high order Legendre spectral element spatial discretization and a least squares time integration scheme. A non-reflective outflow boundary condition is in place to minimize the effect of downstream influence. Smagorinsky model with Van Driest near wall damping is used for sub-grid scale modeling. Comparisons of mean velocity profiles and wall pressure show good agreement with benchmark data. More studies are needed to evaluate the sensitivity of this method on numerical parameters before it is applied to complex engineering problems.

Direct numerical simulation of annular flows

NASA Astrophysics Data System (ADS)

Batchvarov, Assen; Kahouadji, Lyes; Chergui, Jalel; Juric, Damir; Shin, Seungwon; Craster, Richard V.; Matar, Omar K.

2017-11-01

Vertical counter-current two-phase flows are investigated using direct numerical simulations. The computations are carried out using Blue, a front-tracking-based CFD solver. Preliminary results show good qualitative agreement with experimental observations in terms of interfacial phenomena; these include three-dimensional, large-amplitude wave formation, the development of long ligaments, and droplet entrainment. The flooding phenomena in these counter current systems are closely investigated. The onset of flooding in our simulations is compared to existing empirical correlations such as Kutateladze-type and Wallis-type. The effect of varying tube diameter and fluid properties on the flooding phenomena is also investigated in this work. EPSRC, UK, MEMPHIS program Grant (EP/K003976/1), RAEng Research Chair (OKM).

A review of quasi-coherent structures in a numerically simulated turbulent boundary layer

NASA Technical Reports Server (NTRS)

Robinson, S. K.; Kline, S. J.; Spalart, P. R.

1989-01-01

Preliminary results of a comprehensive study of the structural aspects of a numerically simulated number turbulent boundary layer are presented. A direct Navier-Stokes simulation of a flat-plate, zero pressure gradient boundary layer at Re0 = 670 was used. Most of the known nonrandom, coherent features of turbulent boundary layers are confirmed in the simulation, and several new aspects of their spatial character are reported. The spatial relationships between many of the various structures are described, forming the basis for a more complete kinematical picture of boundary layer physics than has been previously known. In particular, the importance of vortex structures of various forms to the generation of Reynolds shear stress is investigated.

Safety Performance of Airborne Separation: Preliminary Baseline Testing

NASA Technical Reports Server (NTRS)

Consiglio, Maria C.; Hoadley, Sherwood T.; Wing, David J.; Baxley, Brian T.

2007-01-01

The Safety Performance of Airborne Separation (SPAS) study is a suite of Monte Carlo simulation experiments designed to analyze and quantify safety behavior of airborne separation. This paper presents results of preliminary baseline testing. The preliminary baseline scenario is designed to be very challenging, consisting of randomized routes in generic high-density airspace in which all aircraft are constrained to the same flight level. Sustained traffic density is varied from approximately 3 to 15 aircraft per 10,000 square miles, approximating up to about 5 times today s traffic density in a typical sector. Research at high traffic densities and at multiple flight levels are planned within the next two years. Basic safety metrics for aircraft separation are collected and analyzed. During the progression of experiments, various errors, uncertainties, delays, and other variables potentially impacting system safety will be incrementally introduced to analyze the effect on safety of the individual factors as well as their interaction and collective effect. In this paper we report the results of the first experiment that addresses the preliminary baseline condition tested over a range of traffic densities. Early results at five times the typical traffic density in today s NAS indicate that, under the assumptions of this study, airborne separation can be safely performed. In addition, we report on initial observations from an exploration of four additional factors tested at a single traffic density: broadcast surveillance signal interference, extent of intent sharing, pilot delay, and wind prediction error.

Deconvolution of acoustic emissions for source localization using time reverse modeling

NASA Astrophysics Data System (ADS)

Kocur, Georg Karl

2017-01-01

Impact experiments on small-scale slabs made of concrete and aluminum were carried out. Wave motion radiated from the epicenter of the impact was recorded as voltage signals by resonant piezoelectric transducers. Numerical simulations of the elastic wave propagation are performed to simulate the physical experiments. The Hertz theory of contact is applied to estimate the force impulse, which is subsequently used for the numerical simulation. Displacements at the transducer positions are calculated numerically. A deconvolution function is obtained by comparing the physical (voltage signal) and the numerical (calculated displacement) experiments. Acoustic emission signals due to pencil-lead breaks are recorded, deconvolved and applied for localization using time reverse modeling.

Validation of model-based deformation correction in image-guided liver surgery via tracked intraoperative ultrasound: preliminary method and results

NASA Astrophysics Data System (ADS)

Clements, Logan W.; Collins, Jarrod A.; Wu, Yifei; Simpson, Amber L.; Jarnagin, William R.; Miga, Michael I.

2015-03-01

Soft tissue deformation represents a significant error source in current surgical navigation systems used for open hepatic procedures. While numerous algorithms have been proposed to rectify the tissue deformation that is encountered during open liver surgery, clinical validation of the proposed methods has been limited to surface based metrics and sub-surface validation has largely been performed via phantom experiments. Tracked intraoperative ultrasound (iUS) provides a means to digitize sub-surface anatomical landmarks during clinical procedures. The proposed method involves the validation of a deformation correction algorithm for open hepatic image-guided surgery systems via sub-surface targets digitized with tracked iUS. Intraoperative surface digitizations were acquired via a laser range scanner and an optically tracked stylus for the purposes of computing the physical-to-image space registration within the guidance system and for use in retrospective deformation correction. Upon completion of surface digitization, the organ was interrogated with a tracked iUS transducer where the iUS images and corresponding tracked locations were recorded. After the procedure, the clinician reviewed the iUS images to delineate contours of anatomical target features for use in the validation procedure. Mean closest point distances between the feature contours delineated in the iUS images and corresponding 3-D anatomical model generated from the preoperative tomograms were computed to quantify the extent to which the deformation correction algorithm improved registration accuracy. The preliminary results for two patients indicate that the deformation correction method resulted in a reduction in target error of approximately 50%.

Asteroid Return Mission Feasibility Study

NASA Technical Reports Server (NTRS)

Brophy, John R.; Gershman, Robert; Landau, Damon; Polk, James; Porter, Chris; Yeomans, Don; Allen, Carlton; Williams, Willie; Asphaug, Erik

2011-01-01

This paper describes an investigation into the technological feasibility of finding, characterizing, robotically capturing, and returning an entire Near-Earth Asteroid (NEA) to the International Space Station (ISS) for scientific investigation, evaluation of its resource potential, determination of its internal structure and other aspects important for planetary defense activities, and to serve as a testbed for human operations in the vicinity of an asteroid. Reasonable projections suggest that several dozen candidates NEAs in the size range of interest (approximately 2-m diameter) will be known before the end of the decade from which a suitable target could be selected. The conceptual mission objective is to return an approximately 10,000-kg asteroid to the ISS in a total flight time of approximately 5 years using a single Evolved Expendable Launch Vehicle. Preliminary calculations indicate that this could be accomplished using a solar electric propulsion (SEP) system with high-power Hall thrusters and a maximum power into the propulsion system of approximately 40 kW. The SEP system would be used to provide all of the post-launch delta V. The asteroid would have an unrestricted Earth return Planetary Protection categorization, and would be curated at the ISS where numerous scientific and resource utilization experiments would be conducted. Asteroid material brought to the ground would be curated at the NASA Johnson Space Center. This preliminary study identified several areas where additional work is required, but no show stoppers were identified for the approach that would return an entire 10,000-kg asteroid to the ISS in a mission that could be launched by the end of this decade.

Monitoring the Microgravity Environment Quality On-board the International Space Station Using Soft Computing Techniques. Part 2; Preliminary System Performance Results

NASA Technical Reports Server (NTRS)

Jules, Kenol; Lin, Paul P.; Weiss, Daniel S.

2002-01-01

This paper presents the preliminary performance results of the artificial intelligence monitoring system in full operational mode using near real time acceleration data downlinked from the International Space Station. Preliminary microgravity environment characterization analysis result for the International Space Station (Increment-2), using the monitoring system is presented. Also, comparison between the system predicted performance based on ground test data for the US laboratory "Destiny" module and actual on-orbit performance, using measured acceleration data from the U.S. laboratory module of the International Space Station is presented. Finally, preliminary on-orbit disturbance magnitude levels are presented for the Experiment of Physics of Colloids in Space, which are compared with on ground test data. The ground test data for the Experiment of Physics of Colloids in Space were acquired from the Microgravity Emission Laboratory, located at the NASA Glenn Research Center, Cleveland, Ohio. The artificial intelligence was developed by the NASA Glenn Principal Investigator Microgravity Services Project to help the principal investigator teams identify the primary vibratory disturbance sources that are active, at any moment of time, on-board the International Space Station, which might impact the microgravity environment their experiments are exposed to. From the Principal Investigator Microgravity Services' web site, the principal investigator teams can monitor via a dynamic graphical display, implemented in Java, in near real time, which event(s) is/are on, such as crew activities, pumps, fans, centrifuges, compressor, crew exercise, structural modes, etc., and decide whether or not to run their experiments, whenever that is an option, based on the acceleration magnitude and frequency sensitivity associated with that experiment. This monitoring system detects primarily the vibratory disturbance sources. The system has built-in capability to detect both known and unknown vibratory disturbance sources. Several soft computing techniques such as Kohonen's Self-Organizing Feature Map, Learning Vector Quantization, Back-Propagation Neural Networks, and Fuzzy Logic were used to design the system.

A Centralized Display for Mission Monitoring

NASA Technical Reports Server (NTRS)

Trujillo, Anna C.

2004-01-01

Humans traditionally experience a vigilance decrement over extended periods of time on reliable systems. One possible solution to aiding operators in monitoring is to use polar-star displays that will show deviations from normal in a more salient manner. The primary objectives of this experiment were to determine if polar-star displays aid in monitoring and preliminary diagnosis of the aircraft state. This experiment indicated that the polar-star display does indeed aid operators in detecting and diagnosing system events. Subjects were able to notice system events earlier and they subjectively reported the polar-star display helped them in monitoring, noticing an event, and diagnosing an event. Therefore, these results indicate that the polar-star display used for monitoring and preliminary diagnosis improves performance in these areas for system related events.

Mechanical testing of bones: the positive synergy of finite-element models and in vitro experiments.

PubMed

Cristofolini, Luca; Schileo, Enrico; Juszczyk, Mateusz; Taddei, Fulvia; Martelli, Saulo; Viceconti, Marco

2010-06-13

Bone biomechanics have been extensively investigated in the past both with in vitro experiments and numerical models. In most cases either approach is chosen, without exploiting synergies. Both experiments and numerical models suffer from limitations relative to their accuracy and their respective fields of application. In vitro experiments can improve numerical models by: (i) preliminarily identifying the most relevant failure scenarios; (ii) improving the model identification with experimentally measured material properties; (iii) improving the model identification with accurately measured actual boundary conditions; and (iv) providing quantitative validation based on mechanical properties (strain, displacements) directly measured from physical specimens being tested in parallel with the modelling activity. Likewise, numerical models can improve in vitro experiments by: (i) identifying the most relevant loading configurations among a number of motor tasks that cannot be replicated in vitro; (ii) identifying acceptable simplifications for the in vitro simulation; (iii) optimizing the use of transducers to minimize errors and provide measurements at the most relevant locations; and (iv) exploring a variety of different conditions (material properties, interface, etc.) that would require enormous experimental effort. By reporting an example of successful investigation of the femur, we show how a combination of numerical modelling and controlled experiments within the same research team can be designed to create a virtuous circle where models are used to improve experiments, experiments are used to improve models and their combination synergistically provides more detailed and more reliable results than can be achieved with either approach singularly.

Critical point wetting drop tower experiment

NASA Technical Reports Server (NTRS)

Kaukler, W. F.; Tcherneshoff, L. M.; Straits, S. R.

1984-01-01

Preliminary results for the Critical Point Wetting CPW Drop Tower Experiment are produced with immiscible systems. Much of the observed phenomena conformed to the anticipated behavior. More drops will be needed to test the CPW theory with these immiscible systems.

Experimental design for research on shock-turbulence interaction

NASA Technical Reports Server (NTRS)

Radcliffe, S. W.

1969-01-01

Report investigates the production of acoustic waves in the interaction of a supersonic shock and a turbulence environment. The five stages of the investigation are apparatus design, development of instrumentation, preliminary experiment, turbulence generator selection, and main experiments.

Perceived state of self during motion can differentially modulate numerical magnitude allocation.

PubMed

Arshad, Q; Nigmatullina, Y; Roberts, R E; Goga, U; Pikovsky, M; Khan, S; Lobo, R; Flury, A-S; Pettorossi, V E; Cohen-Kadosh, R; Malhotra, P A; Bronstein, A M

2016-09-01

Although a direct relationship between numerical allocation and spatial attention has been proposed, recent research suggests that these processes are not directly coupled. In keeping with this, spatial attention shifts induced either via visual or vestibular motion can modulate numerical allocation in some circumstances but not in others. In addition to shifting spatial attention, visual or vestibular motion paradigms also (i) elicit compensatory eye movements which themselves can influence numerical processing and (ii) alter the perceptual state of 'self', inducing changes in bodily self-consciousness impacting upon cognitive mechanisms. Thus, the precise mechanism by which motion modulates numerical allocation remains unknown. We sought to investigate the influence that different perceptual experiences of motion have upon numerical magnitude allocation while controlling for both eye movements and task-related effects. We first used optokinetic visual motion stimulation (OKS) to elicit the perceptual experience of either 'visual world' or 'self'-motion during which eye movements were identical. In a second experiment, we used a vestibular protocol examining the effects of perceived and subliminal angular rotations in darkness, which also provoked identical eye movements. We observed that during the perceptual experience of 'visual world' motion, rightward OKS-biased judgments towards smaller numbers, whereas leftward OKS-biased judgments towards larger numbers. During the perceptual experience of 'self-motion', judgments were biased towards larger numbers irrespective of the OKS direction. Contrastingly, vestibular motion perception was found not to modulate numerical magnitude allocation, nor was there any differential modulation when comparing 'perceived' vs. 'subliminal' rotations. We provide a novel demonstration that numerical magnitude allocation can be differentially modulated by the perceptual state of self during visual but not vestibular mediated motion. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

MISSE-7 MESA Miniaturized Electrostatic Analyzer - Ion Spectra Analysis Preliminary Results

NASA Astrophysics Data System (ADS)

Enloe, C. L.; Balthazor, R. L.; McHarg, M. G.; Clark, A. L.; Waite, D.; Wallerstein, A. J.; Wilson, K. A.

2011-12-01

The 7th Materials on the International Space Station Experiment (MISSE-7) was launched in November 2009 and retrieved on STS-134 in April 2011. One of the onboard experiments, the Miniaturized Electrostatic Analyzer (MESA), is a small low-cost low-size/weight/power ion and electron spectrometer that was pointed into ram during the majority of the time onboard. Over 800 Mb of data has been obtained by taking spectra every three minutes on-orbit. The data has been analyzed with a novel "parameterizing the parameters" method suitable for on-orbit data analysis using low-cost microcontrollers. Preliminary results are shown.

Onyx, a New Liquid Embolic Material for Peripheral Interventions: Preliminary Experience in Aneurysm, Pseudoaneurysm, and Pulmonary Arteriovenous Malformation Embolization

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

Vanninen, Ritva L., E-mail: ritva.vanninen@kuh.fi; Manninen, I.

Purpose. To describe our preliminary experience with a new liquid embolization agent, Onyx, in peripheral interventions. Methods and results. We successfully treated two peripheral aneurysms (one in an internal iliac artery, one in a thoracic collateral artery of an aortic coarctation), two peripheral pseudoaneurysms (one in a lumbar artery, one in a renal artery), and one pulmonary arteriovenous malformation. Conclusion. Onyx is a promising alternative embolic material for peripheral interventions. It can be combined with coils in selected cases, and balloon catheters can be effectively used during slow injection of embolic material to control flow and protect the aneurysm neck.

A new oral contraceptive regimen for endometriosis management: preliminary experience with 24/4-day drospirenone/ethinylestradiol 3 mg/20 mcg.

PubMed

Mabrouk, Mohamed; Solfrini, Serena; Frascà, Clarissa; Del Forno, Simona; Montanari, Giulia; Ferrini, Giulia; Paradisi, Roberto; Seracchioli, Renato

2012-06-01

We report our preliminary experience with the use of a low-dose oral contraceptive containing Drospirenone/Ethinylestradiol 3 mg/20 mcg, both in cyclic and continuous regimen for endometriosis management. A total of 93 women were retrospectively included: 52 were treated by medical therapy (exclusive combined oral contraceptives (COC)-users), while 41 were submitted to surgery followed by postoperative therapy (postoperative COC-users). A clinical examination was performed at baseline and at 6-months follow-up. Presence and intensity of endometriosis-related symptoms were assessed by a visual analogue scale. Presence and dimension of endometriotic lesions were evaluated by transvaginal ultrasonography. Adverse effects and tolerability were analysed. In exclusive COC-users, significant reductions in dysmenorrhoea and dyspareunia scores and in endometrioma mean diameter were observed at follow-up. In postoperative COC-users, anatomical and symptom recurrence rates at follow-up were 4.9% and 17%, respectively. The most frequent adverse effects were spotting and headache. No difference between cyclic and continuous regimen in terms of symptom relief, lesion progression and tolerability was observed. From our preliminary experience, Drospirenone/Ethinylestradiol 3 mg/20 mcg seems to be promising in endometriosis management.

Numerical simulations of SHPB experiments for the dynamic compressive strength and failure of ceramics

NASA Astrophysics Data System (ADS)

Anderson, Charles E., Jr.; O'Donoghue, Padraic E.; Lankford, James; Walker, James D.

1992-06-01

Complementary to a study of the compressive strength of ceramic as a function of strain rate and confinement, numerical simulations of the split-Hopkinson pressure bar (SHPB) experiments have been performed using the two-dimensional wave propagation computer program HEMP. The numerical effort had two main thrusts. Firstly, the interpretation of the experimental data relies on several assumptions. The numerical simulations were used to investigate the validity of these assumptions. The second part of the effort focused on computing the idealized constitutive response of a ceramic within the SHPB experiment. These numerical results were then compared against experimental data. Idealized models examined included a perfectly elastic material, an elastic-perfectly plastic material, and an elastic material with failure. Post-failure material was modeled as having either no strength, or a strength proportional to the mean stress. The effects of confinement were also studied. Conclusions concerning the dynamic behavior of a ceramic up to and after failure are drawn from the numerical study.

Numerical and experimental study of expiratory flow in the case of major upper airway obstructions with fluid structure interaction

NASA Astrophysics Data System (ADS)

Chouly, F.; van Hirtum, A.; Lagrée, P.-Y.; Pelorson, X.; Payan, Y.

2008-02-01

This study deals with the numerical prediction and experimental description of the flow-induced deformation in a rapidly convergent divergent geometry which stands for a simplified tongue, in interaction with an expiratory airflow. An original in vitro experimental model is proposed, which allows measurement of the deformation of the artificial tongue, in condition of major initial airway obstruction. The experimental model accounts for asymmetries in geometry and tissue properties which are two major physiological upper airway characteristics. The numerical method for prediction of the fluid structure interaction is described. The theory of linear elasticity in small deformations has been chosen to compute the mechanical behaviour of the tongue. The main features of the flow are taken into account using a boundary layer theory. The overall numerical method entails finite element solving of the solid problem and finite differences solving of the fluid problem. First, the numerical method predicts the deformation of the tongue with an overall error of the order of 20%, which can be seen as a preliminary successful validation of the theory and simulations. Moreover, expiratory flow limitation is predicted in this configuration. As a result, both the physical and numerical models could be useful to understand this phenomenon reported in heavy snorers and apneic patients during sleep.

Probabilistic Assessment of National Wind Tunnel

NASA Technical Reports Server (NTRS)

Shah, A. R.; Shiao, M.; Chamis, C. C.

1996-01-01

A preliminary probabilistic structural assessment of the critical section of National Wind Tunnel (NWT) is performed using NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) computer code. Thereby, the capabilities of NESSUS code have been demonstrated to address reliability issues of the NWT. Uncertainties in the geometry, material properties, loads and stiffener location on the NWT are considered to perform the reliability assessment. Probabilistic stress, frequency, buckling, fatigue and proof load analyses are performed. These analyses cover the major global and some local design requirements. Based on the assumed uncertainties, the results reveal the assurance of minimum 0.999 reliability for the NWT. Preliminary life prediction analysis results show that the life of the NWT is governed by the fatigue of welds. Also, reliability based proof test assessment is performed.

Preliminary thermoluminescence and optically stimulated luminescence investigation of commercial pharmaceutical preparations towards the drug sterilization dosimetry.

PubMed

Kazakis, Nikolaos A; Tsirliganis, Nestor C; Kitis, George

2014-09-01

Drug sterilization with ionizing radiation is a well-established technology and is gaining ground the last decades due to its numerous advantages. Identification of irradiated drugs would be interesting and, in this respect, the present work aims, for the first time to the authors' best knowledge, to explore whether OSL and TL can be employed as methods for post-sterilization dosimetry on commercial drugs, i.e., as tools for the detection of irradiated drugs. Five widely used drugs, i.e., Daktarin(®), Aspirin(®), Panadol(®), Brufen(®) and Procef(®), are used for this purpose. Preliminary findings are very promising towards the post-sterilization dosimetry and the use of commercial drugs for normal and/or accidental dosimetry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Student Solution Manual for Mathematical Methods for Physics and Engineering Third Edition

NASA Astrophysics Data System (ADS)

Riley, K. F.; Hobson, M. P.

2006-03-01

Preface; 1. Preliminary algebra; 2. Preliminary calculus; 3. Complex numbers and hyperbolic functions; 4. Series and limits; 5. Partial differentiation; 6. Multiple integrals; 7. Vector algebra; 8. Matrices and vector spaces; 9. Normal modes; 10. Vector calculus; 11. Line, surface and volume integrals; 12. Fourier series; 13. Integral transforms; 14. First-order ordinary differential equations; 15. Higher-order ordinary differential equations; 16. Series solutions of ordinary differential equations; 17. Eigenfunction methods for differential equations; 18. Special functions; 19. Quantum operators; 20. Partial differential equations: general and particular; 21. Partial differential equations: separation of variables; 22. Calculus of variations; 23. Integral equations; 24. Complex variables; 25. Application of complex variables; 26. Tensors; 27. Numerical methods; 28. Group theory; 29. Representation theory; 30. Probability; 31. Statistics.

Development of an Object-Oriented Turbomachinery Analysis Code within the NPSS Framework

NASA Technical Reports Server (NTRS)

Jones, Scott M.

2014-01-01

During the preliminary or conceptual design phase of an aircraft engine, the turbomachinery designer has a need to estimate the effects of a large number of design parameters such as flow size, stage count, blade count, radial position, etc. on the weight and efficiency of a turbomachine. Computer codes are invariably used to perform this task however, such codes are often very old, written in outdated languages with arcane input files, and rarely adaptable to new architectures or unconventional layouts. Given the need to perform these kinds of preliminary design trades, a modern 2-D turbomachinery design and analysis code has been written using the Numerical Propulsion System Simulation (NPSS) framework. This paper discusses the development of the governing equations and the structure of the primary objects used in OTAC.

Dynamic Eye gaze and its Potential in Virtual Reality Based Applications for Children with Autism Spectrum Disorders.

PubMed

Lahiri, Uttama; Trewyn, Adam; Warren, Zachary; Sarkar, Nilanjan

2011-01-01

Children with Autism Spectrum Disorder are often characterized by deficits in social communication skills. While evidence suggests that intensive individualized interventions can improve aspects of core deficits in Autism Spectrum Disorder, at present numerous potent barriers exist related to accessing and implementing such interventions. Researchers are increasingly employing technology to develop more accessible, quantifiable, and individualized intervention tools to address core vulnerabilities related to autism. The present study describes the development and preliminary application of a Virtual Reality technology aimed at facilitating improvements in social communication skills for adolescents with autism. We present preliminary data from the usability study of this technological application for six adolescents with autism and discuss potential future development and application of adaptive Virtual Reality technology within an intervention framework.

Numerical modeling of aquifer thermal energy storage

NASA Astrophysics Data System (ADS)

Tsang, C. F.; Doughty, C.; Kincaid, C. T.

1982-12-01

During 1981 and 1982, Auburn University has been performing a three cycle ATES field experiment in Mobile County, Alabama. Details of the experiment are described elsewhere in this volume. Concurrent with the first two cycles (59 C and 82 C), Lawrence Berkeley Laboratory (LBL) did numerical simulations based on field operating conditions to predict the outcome of each cycle before its conclusion. Prior to the third cycle, a series of numerical simulations were made to aid in the design of an experiment that would yield the highest recovery factor possible.

Can a numerically stable subgrid-scale model for turbulent flow computation be ideally accurate?: a preliminary theoretical study for the Gaussian filtered Navier-Stokes equations.

PubMed

Ida, Masato; Taniguchi, Nobuyuki

2003-09-01

This paper introduces a candidate for the origin of the numerical instabilities in large eddy simulation repeatedly observed in academic and practical industrial flow computations. Without resorting to any subgrid-scale modeling, but based on a simple assumption regarding the streamwise component of flow velocity, it is shown theoretically that in a channel-flow computation, the application of the Gaussian filtering to the incompressible Navier-Stokes equations yields a numerically unstable term, a cross-derivative term, which is similar to one appearing in the Gaussian filtered Vlasov equation derived by Klimas [J. Comput. Phys. 68, 202 (1987)] and also to one derived recently by Kobayashi and Shimomura [Phys. Fluids 15, L29 (2003)] from the tensor-diffusivity subgrid-scale term in a dynamic mixed model. The present result predicts that not only the numerical methods and the subgrid-scale models employed but also only the applied filtering process can be a seed of this numerical instability. An investigation concerning the relationship between the turbulent energy scattering and the unstable term shows that the instability of the term does not necessarily represent the backscatter of kinetic energy which has been considered a possible origin of numerical instabilities in large eddy simulation. The present findings raise the question whether a numerically stable subgrid-scale model can be ideally accurate.

Bullying Experiences among Children and Youth with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Cappadocia, M. Catherine; Weiss, Jonathan A.; Pepler, Debra

2012-01-01

Few studies have investigated bullying experiences among children diagnosed with autism spectrum disorders (ASD); however, preliminary research suggests that children with ASD are at greater risk for being bullied than typically developing peers. The aim of the current study was to build an understanding of bullying experiences among children with…

The Impact of Study Abroad Experiences on Vocational Identity among College Students

ERIC Educational Resources Information Center

Kronholz, Julia F.; Osborn, Debra S.

2016-01-01

The purpose of this study was to determine preliminary findings regarding the effect of a study abroad experience on vocational identity and career decision-making as defined by Cognitive Information Processing (CIP) theory (Sampson et al., 2004). The results revealed that a study abroad experience significantly impacts college students'…

Experience from a multicentre stroke register: a preliminary report

PubMed Central

Hatano, S.

1976-01-01

In collaboration with 15 centres in 10 countries of Africa, Asia, and Europe, WHO started a pilot study of a community-based stroke register, with standardized methods. Preliminary data were obtained on 6395 new cases of stroke in defined study communities, from May 1971 to September 1974. Information on incidence rates, clinical profiles, diagnosis, management, and course and prognosis for these patients is given. PMID:1088404

Pathways to the Future: A Longitudinal Study of Young Americans. Preliminary Report: Youth and the Labor Market--1979.

ERIC Educational Resources Information Center

Borus, Michael E.; And Others

This monograph presents preliminary cross-tabulation analyses of the 1979 National Longitudinal Survey of Youth Labor Market Experience of 12,693 youth of ages 14-21 who will be interviewed annually for at least five years. (Hispanic; non-Hispanic black; and non-Hispanic, non-black, poor youth were oversampled.) Each of the twenty-four topics…

A Preliminary Investigation of the Effects of Giving Testimony and Learning Yogic Breathing Techniques on Battered Women's Feelings of Depression

ERIC Educational Resources Information Center

Franzblau, Susan H.; Echevarria, Sonia; Smith, Michelle; Van Cantfort, Thomas E.

2008-01-01

Researchers have shown that mood and sense of control over one's life are significantly affected by testimony and other forms of disclosure and that learning to control breathing has positive effects on mood and anxiety. This preliminary experiment tests whether African American and European American abused women who give testimony about their…

Chemical Analysis of the Moon at the Surveyor VI Landing Site: Preliminary Results.

PubMed

Turkevich, A L; Patterson, J H; Franzgrote, E J

1968-06-07

The alpha-scattering experiment aboard soft-landing Surveyor VI has provided a chemical analysis of the surface of the moon in Sinus Medii. The preliminary results indicate that, within experimental errors, the composition is the same as that found by Surveyor V in Mare Tranquillitatis. This finding suggests that large portions of the lunar maria resemble basalt in composition.

Visual Knowledge in Tactical Planning: Preliminary Knowledge Acquisition Phase 1 Technical Report

DTIC Science & Technology

1990-04-05

MANAGEMENT INFORMATION , COMMUNICATIONS, AND COMPUTER SCIENCES Visual Knowledge in Tactical Planning: Preliminary Knowledge Acquisition Phase I Technical...perceived provides information in multiple modalities and, in fact, we may rely on a non-verbal mode for much of our understanding of the situation...some tasks, almost all the pertinent information is provided via diagrams, maps, znd other illustrations. Visual Knowledge Visual experience forms a

SARDA HITL Preliminary Human Factors Measures and Analyses

NASA Technical Reports Server (NTRS)

Hyashi, Miwa; Dulchinos, Victoria

2012-01-01

Human factors data collected during the SARDA HITL Simulation Experiment include a variety of subjective measures, including the NASA TLX, questionnaire questions regarding situational awareness, advisory usefulness, UI usability, and controller trust. Preliminary analysis of the TLX data indicate that workload may not be adversely affected by use of the advisories, additionally, the controller's subjective ratings of the advisories may suggest acceptance of the tool.

Preliminary data for the 20 May 1974, simultaneous evaluation of remote sensors experiment. [water pollution monitoring

NASA Technical Reports Server (NTRS)

Johnson, R. W.; Batten, C. E.; Bowker, D. E.; Bressette, W. E.; Grew, G. W.

1975-01-01

Several remote sensors were simultaneously used to collect data over the tidal James River from Hopewell to Norfolk, Virginia. Sensors evaluated included the Multichannel-Ocean Color Sensor, multispectral scanners, and multispectral photography. Ground truth measurements and remotely sensed data are given. Preliminary analysis indicates that suspended sediment and concentrated industrial effluent are observable from all sensors.

The distance effect in numerical memory-updating tasks.

PubMed

Lendínez, Cristina; Pelegrina, Santiago; Lechuga, Teresa

2011-05-01

Two experiments examined the role of numerical distance in updating numerical information in working memory. In the first experiment, participants had to memorize a new number only when it was smaller than a previously memorized number. In the second experiment, updating was based on an external signal, which removed the need to perform any numerical comparison. In both experiments, distance between the memorized number and the new one was manipulated. The results showed that smaller distances between the new and the old information led to shorter updating times. This graded facilitation suggests that the process by which information is substituted in the focus of attention involves maintaining the shared features between the new and the old number activated and selecting other new features to be activated. Thus, the updating cost may be related to amount of new features to be activated in the focus of attention.

Application of Pi Preform Composite Joints in Fabrication of NASA Composite Crew Module Demonstration Structure

NASA Technical Reports Server (NTRS)

Higgins, John E.; Pelham, Larry

2008-01-01

This paper will describe unique and extensive use of pre-woven and impregnated pi cross-sections in fabrication of a carbon composite demonstration structure for the Composite Crew Module (CCM) Program. The program is managed by the NASA Safety and Engineering Center with participants from ten NASA Centers and AFRL. Multiple aerospace contractors are participating in the design development, tooling and fabrication effort as well. The goal of the program is to develop an agency wide design team for composite habitable spacecraft. The specific goals for this development project are: a) To gain hands on experience in design, building and testing a composite crew module. b) To validate key assumptions by resolving composite spacecraft design details through fabrication and testing of hardware. This paper will focus on the design and fabrication issues supporting selection of the Lockheed Martin patented Pi pre-form to provide sound composite joints a numerous locations in the structure. This abstract is based on Preliminary Design data. The final design will continue to evolve through the fall of 2007 with fabrication mostly completed by conference date.

Mesenchymal Stem Cell Transplantation in Multiple Sclerosis

PubMed Central

Cohen, Jeffrey A.

2013-01-01

Mesenchymal stem cells (MSCs) are a pluripotent non-hematopoietic precursor cells that can be isolated from bone marrow and numerous other tissues, culture-expanded to purity, and induced to differentiate in vitro and in vivo into mesodermal derivatives. MSCs exhibit many phenotypic and functional similarities to pericytes. The immunomodulatory, tissue protective, and repair-promoting properties of MSCs demonstrated both in vitro and in animal models make them an attractive potential therapy for MS and other conditions characterized by inflammation and/or tissue injury. Other potential advantages of MSCs as a therapeutic include the relative ease of culture expansion, relative immunoprivilege allowing allogeneic transplantation, and their ability to traffic from blood to areas of tissue allowing intravascular administration. The overall published experience with MSC transplantation in MS is modest, but several small case series and preliminary studies yielded promising results. Several groups, including us, recently initiated formal studies of autologous, culture-expanded, bone-marrow-derived MSC transplantation in MS. Although there are several potential safety concerns, to date, the procedure has been well tolerated. Future studies that more definitively assess efficacy also will need to address several technical issues. PMID:23294498

Evaluation of ground motion scaling methods for analysis of structural systems

USGS Publications Warehouse

O'Donnell, A. P.; Beltsar, O.A.; Kurama, Y.C.; Kalkan, E.; Taflanidis, A.A.

2011-01-01

Ground motion selection and scaling comprises undoubtedly the most important component of any seismic risk assessment study that involves time-history analysis. Ironically, this is also the single parameter with the least guidance provided in current building codes, resulting in the use of mostly subjective choices in design. The relevant research to date has been primarily on single-degree-of-freedom systems, with only a few studies using multi-degree-of-freedom systems. Furthermore, the previous research is based solely on numerical simulations with no experimental data available for the validation of the results. By contrast, the research effort described in this paper focuses on an experimental evaluation of selected ground motion scaling methods based on small-scale shake-table experiments of re-configurable linearelastic and nonlinear multi-story building frame structure models. Ultimately, the experimental results will lead to the development of guidelines and procedures to achieve reliable demand estimates from nonlinear response history analysis in seismic design. In this paper, an overview of this research effort is discussed and preliminary results based on linear-elastic dynamic response are presented. ?? ASCE 2011.

Molten salt thermal energy storage subsystem for solar thermal central receiver plants

NASA Astrophysics Data System (ADS)

Wells, P. B.; Nassopoulos, G. P.

1982-02-01

The development of a low cost thermal energy storage subsystem for large solar plants is described. Molten nitrate salt is used as both the solar plant working fluid and the storage medium. The storage system consists of a specially designed hot tank to hold salt at a storage temperature of 839K (1050 deg F) and a separate carbon steel cold tank to hold the salt after its thermal energy has been extracted to generate steam. The hot tank is lined with insulating firebrick to reduce the shell temperature to 561K (550 deg F) so that a low cost carbon steel shell is used. The internal insulation is protected from the hot salt by a unique metal liner with orthogonal corrugations to allow for numerous cycles of thermal expansion and contraction. A preliminary design for a large commercial size plant (1200 MWh sub +), a laboratory test program for the critical components, and the design, construction, and test of a small scale (7 MWH sub t) research experiment at the Central Receiver Test Facility in Albuquerque, New Mexico is described.

A graphical approach to electric sail mission design with radial thrust

NASA Astrophysics Data System (ADS)

Mengali, Giovanni; Quarta, Alessandro A.; Aliasi, Generoso

2013-02-01

This paper describes a semi-analytical approach to electric sail mission analysis under the assumption that the spacecraft experiences a purely radial, outward, propulsive acceleration. The problem is tackled by means of the potential well concept, a very effective idea that was originally introduced by Prussing and Coverstone in 1998. Unlike a classical procedure that requires the numerical integration of the equations of motion, the proposed method provides an estimate of the main spacecraft trajectory parameters, as its maximum and minimum attainable distance from the Sun, with the simple use of analytical relationships and elementary graphs. A number of mission scenarios clearly show the effectiveness of the proposed approach. In particular, when the spacecraft parking orbit is either circular or elliptic it is possible to find the optimal performances required to reach an escape condition or a given distance from the Sun. Another example is given by the optimal strategy required to reach a heliocentric Keplerian orbit of prescribed orbital period. Finally the graphical approach is applied to the preliminary design of a nodal mission towards a Near Earth Asteroid.

A Model of Regularization Parameter Determination in Low-Dose X-Ray CT Reconstruction Based on Dictionary Learning

PubMed Central

Zhang, Cheng; Zhang, Tao; Li, Ming; Lu, Yanfei; You, Jiali; Guan, Yihui

2015-01-01

In recent years, X-ray computed tomography (CT) is becoming widely used to reveal patient's anatomical information. However, the side effect of radiation, relating to genetic or cancerous diseases, has caused great public concern. The problem is how to minimize radiation dose significantly while maintaining image quality. As a practical application of compressed sensing theory, one category of methods takes total variation (TV) minimization as the sparse constraint, which makes it possible and effective to get a reconstruction image of high quality in the undersampling situation. On the other hand, a preliminary attempt of low-dose CT reconstruction based on dictionary learning seems to be another effective choice. But some critical parameters, such as the regularization parameter, cannot be determined by detecting datasets. In this paper, we propose a reweighted objective function that contributes to a numerical calculation model of the regularization parameter. A number of experiments demonstrate that this strategy performs well with better reconstruction images and saving of a large amount of time. PMID:26550024

Design and Analysis of A Spin-Stabilized Projectile Experimental Apparatus

NASA Astrophysics Data System (ADS)

Siegel, Noah; Rodebaugh, Gregory; Elkins, Christopher; van Poppel, Bret; Benson, Michael; Cremins, Michael; Lachance, Austin; Ortega, Raymond; Vanderyacht, Douglas

2017-11-01

Spinning objects experience an effect termed `The Magnus Moment' due to an uneven pressure distribution based on rotation within a crossflow. Unlike the Magnus force, which is often small for spin-stabilized projectiles, the Magnus moment can have a strong detrimental effect on aerodynamic flight stability. Simulations often fail to accurately predict the Magnus moment in the subsonic flight regime. In an effort to characterize the conditions that cause the Magnus moment, researchers in this work employed Magnetic Resonance Velocimetry (MRV) techniques to measure three dimensional, three component, sub-millimeter resolution fluid velocity fields around a scaled model of a spinning projectile in flight. The team designed, built, and tested using a novel water channel apparatus that was fully MRI-compliant - water-tight and non-ferrous - and capable of spinning a projectile at a constant rotational speed. A supporting numerical simulation effort informed the design process of the scaled projectile to thicken the hydrodynamic boundary layer near the outer surface of the projectile. Preliminary testing produced two-dimensional and three-dimensional velocity data and revealed an asymmetric boundary layer around the projectile, which is indicative of the Magnus effect.

Combined sphere-spheroid particle model for the retrieval of the microphysical aerosol parameters via regularized inversion of lidar data

NASA Astrophysics Data System (ADS)

Samaras, Stefanos; Böckmann, Christine; Nicolae, Doina

2016-06-01

In this work we propose a two-step advancement of the Mie spherical-particle model accounting for particle non-sphericity. First, a naturally two-dimensional (2D) generalized model (GM) is made, which further triggers analogous 2D re-definitions of microphysical parameters. We consider a spheroidal-particle approach where the size distribution is additionally dependent on aspect ratio. Second, we incorporate the notion of a sphere-spheroid particle mixture (PM) weighted by a non-sphericity percentage. The efficiency of these two models is investigated running synthetic data retrievals with two different regularization methods to account for the inherent instability of the inversion procedure. Our preliminary studies show that a retrieval with the PM model improves the fitting errors and the microphysical parameter retrieval and it has at least the same efficiency as the GM. While the general trend of the initial size distributions is captured in our numerical experiments, the reconstructions are subject to artifacts. Finally, our approach is applied to a measurement case yielding acceptable results.

Model Wind Turbines Tested at Full-Scale Similarity

NASA Astrophysics Data System (ADS)

Miller, M. A.; Kiefer, J.; Westergaard, C.; Hultmark, M.

2016-09-01

The enormous length scales associated with modern wind turbines complicate any efforts to predict their mechanical loads and performance. Both experiments and numerical simulations are constrained by the large Reynolds numbers governing the full- scale aerodynamics. The limited fundamental understanding of Reynolds number effects in combination with the lack of empirical data affects our ability to predict, model, and design improved turbines and wind farms. A new experimental approach is presented, which utilizes a highly pressurized wind tunnel (up to 220 bar). It allows exact matching of the Reynolds numbers (no matter how it is defined), tip speed ratios, and Mach numbers on a geometrically similar, small-scale model. The design of a measurement and instrumentation stack to control the turbine and measure the loads in the pressurized environment is discussed. Results are then presented in the form of power coefficients as a function of Reynolds number and Tip Speed Ratio. Due to gearbox power loss, a preliminary study has also been completed to find the gearbox efficiency and the resulting correction has been applied to the data set.

Contact angle change during evaporation of near-critical liquids

NASA Astrophysics Data System (ADS)

Nikolayev, Vadim; Hegseth, John; Beysens, Daniel

1998-11-01

An unexpected change of the dynamic contact angle was recently observed in a near-critical liquid-gas system in a space experiment. While the near-critical liquid completely wets a solid under equilibrium conditions, the apparent contact angle changed from 0^circ to about 120^circ during evaporation. We propose an explanation for this phenomenon by taking into account vapor recoil due to evaporation (motion of the vapor from the free liquid surface). This force is normal to the vapor-liquid interface and is directed towards the liquid. It increases sharply near the triple contact line. Near the critical point, where the surface tension force is very weak, the vapor recoil force can be important enough to change the apparent contact angle. A similar effect can also explain the drying of a heater during boiling at high heat flux. The drying greatly reduces the heat transfer to the liquid causing the heater to melt. This phenomenon is called ``boiling crisis", ``burnout" or ``Departure from Nuclear Boiling". We report the preliminary results of the numerical simulation of the liquid evaporation by the Boundary Element method.

Field experience with aquifer thermal energy storage

NASA Astrophysics Data System (ADS)

Kannberg, L. D.

1987-11-01

Aquifer thermal energy storage (ATES) has the potential to provide storage for large-scale building heating and cooling at many sites in the US. However, implementation requires careful attention to site geohydraulic and geochemical characteristics. Field tests in the US have shown the over 60% of the heat injected at temperatures over 100 C can be recovered on a seasonal cycle. Similarly, aquifer storage of shilled ground water can provide building cooling with annual cooling electrical energy reductions of over 50% and a reduction in summer peak cooling electrical usage by as much as a factor of 20. A number of projects have been built and operated around the world. China has installed numerous ATES systems in many major cities. Installations in Europe and Scandinavia are almost exclusively low-temperature heat storage systems that use heat pumps. Two high-temperature systems (over 100 C) are in operation or undergoing preliminary testing: one in Denmark, the other in France. Heat ATES often requires water treatment to prevent precipitation of calcium and magnesium carbonates. At some sites, consideration of other geochemical and microbiological issues (such as iron bacteria) must be resolved.

Magnetic Resonance Poroelastography: An Algorithm for Estimating the Mechanical Properties of Fluid-Saturated Soft Tissues

PubMed Central

Perriñez, Phillip R.; Kennedy, Francis E.; Van Houten, Elijah E. W.; Weaver, John B.; Paulsen, Keith D.

2010-01-01

Magnetic Resonance Poroelastography (MRPE) is introduced as an alternative to single-phase model-based elastographic reconstruction methods. A three-dimensional (3D) finite element poroelastic inversion algorithm was developed to recover the mechanical properties of fluid-saturated tissues. The performance of this algorithm was assessed through a variety of numerical experiments, using synthetic data to probe its stability and sensitivity to the relevant model parameters. Preliminary results suggest the algorithm is robust in the presence of noise and capable of producing accurate assessments of the underlying mechanical properties in simulated phantoms. Further, a 3D time-harmonic motion field was recorded for a poroelastic phantom containing a single cylindrical inclusion and used to assess the feasibility of MRPE image reconstruction from experimental data. The elastograms obtained from the proposed poroelastic algorithm demonstrate significant improvement over linearly elastic MRE images generated using the same data. In addition, MRPE offers the opportunity to estimate the time-harmonic pressure field resulting from tissue excitation, highlighting the potential for its application in the diagnosis and monitoring of disease processes associated with changes in interstitial pressure. PMID:20199912

Long-duration heat load measurement approach by novel apparatus design and highly efficient algorithm

NASA Astrophysics Data System (ADS)

Zhu, Yanwei; Yi, Fajun; Meng, Songhe; Zhuo, Lijun; Pan, Weizhen

2017-11-01

Improving the surface heat load measurement technique for vehicles in aerodynamic heating environments is imperative, regarding aspects of both the apparatus design and identification efficiency. A simple novel apparatus is designed for heat load identification, taking into account the lessons learned from several aerodynamic heating measurement devices. An inverse finite difference scheme (invFDM) for the apparatus is studied to identify its surface heat flux from the interior temperature measurements with high efficiency. A weighted piecewise regression filter is also proposed for temperature measurement prefiltering. Preliminary verification of the invFDM scheme and the filter is accomplished via numerical simulation experiments. Three specific pieces of apparatus have been concretely designed and fabricated using different sensing materials. The aerodynamic heating process is simulated by an inductively coupled plasma wind tunnel facility. The identification of surface temperature and heat flux from the temperature measurements is performed by invFDM. The results validate the high efficiency, reliability and feasibility of heat load measurements with different heat flux levels utilizing the designed apparatus and proposed method.

Optical fringe-reflection deflectometry with sparse representation

NASA Astrophysics Data System (ADS)

Xiao, Yong-Liang; Li, Sikun; Zhang, Qican; Zhong, Jianxin; Su, Xianyu; You, Zhisheng

2018-05-01

Optical fringe-reflection deflectometry is a surprisingly attractive scratch detection technique for specular surfaces owing to its unparalleled local sensibility. Full-field surface topography is obtained from a measured normal field using gradient integration. However, there may not be an ideal measured gradient field for deflectometry reconstruction in practice. Both the non-integrability condition and various kinds of image noise distributions, which are present in the indirect measured gradient field, may lead to ambiguity about the scratches on specular surfaces. In order to reduce misjudgment of scratches, sparse representation is introduced into the Southwell curl equation for deflectometry. The curl can be represented as a linear combination of the given redundant dictionary for curl and the sparsest solution for gradient refinement. The non-integrability condition and noise permutation can be overcome with sparse representation for gradient refinement. Numerical simulations demonstrate that the accuracy rate of judgment of scratches can be enhanced with sparse representation compared to the standard least-squares integration. Preliminary experiments are performed with the application of practical measured deflectometric data to verify the validity of the algorithm.

Efficient Spatio-Temporal Local Binary Patterns for Spontaneous Facial Micro-Expression Recognition

PubMed Central

Wang, Yandan; See, John; Phan, Raphael C.-W.; Oh, Yee-Hui

2015-01-01

Micro-expression recognition is still in the preliminary stage, owing much to the numerous difficulties faced in the development of datasets. Since micro-expression is an important affective clue for clinical diagnosis and deceit analysis, much effort has gone into the creation of these datasets for research purposes. There are currently two publicly available spontaneous micro-expression datasets—SMIC and CASME II, both with baseline results released using the widely used dynamic texture descriptor LBP-TOP for feature extraction. Although LBP-TOP is popular and widely used, it is still not compact enough. In this paper, we draw further inspiration from the concept of LBP-TOP that considers three orthogonal planes by proposing two efficient approaches for feature extraction. The compact robust form described by the proposed LBP-Six Intersection Points (SIP) and a super-compact LBP-Three Mean Orthogonal Planes (MOP) not only preserves the essential patterns, but also reduces the redundancy that affects the discriminality of the encoded features. Through a comprehensive set of experiments, we demonstrate the strengths of our approaches in terms of recognition accuracy and efficiency. PMID:25993498

Theoretical studies in support of the 3M-vapor transport (PVTOS-) experiments

NASA Technical Reports Server (NTRS)

Rosner, Daniel E.; Keyes, David E.

1989-01-01

Results are reported for a preliminary theoretical study of the coupled mass-, momentum-, and heat-transfer conditions expected within small ampoules used to grow oriented organic solid (OS-) films, by physical vapor transport (PVT) in microgravity environments. It is show that previous studies made restrictive assumptions (e.g., smallness of delta T/T, equality of molecular diffusivities) not valid under PVTOS conditions, whereas the important phenomena of sidewall gas creep, Soret transport of the organic vapor, and large vapor phase supersaturations associated with the large prevailing temperature gradients were not previously considered. Rational estimates are made of the molecular transport properties relevant to copper-phthalocyanine monomeric vapor in a gas mixture containing H2(g) and Xe(g). Efficient numerical methods have been developed and are outlined/illustrated here to making steady axisymmetric gas flow calculations within such ampoules, allowing for realistic realistic delta T/T(sub)w-values, and even corrections to Navier-Stokes-Fourier 'closure' for the governing continuum differential equations. High priority follow-on studies are outlined based on these new results.

Preliminary assessments of CO2 storage in carbonate formations: a case study from Malaysia

NASA Astrophysics Data System (ADS)

Raza, Arshad; Gholami, Raoof; Rezaee, Reza; Bing, Chua Han; Nagarajan, Ramasamy; Hamid, Mohamed Ali

2017-06-01

The preliminary assessment of depleted reservoirs prior to the injection of CO2 is an essential step to ensure the safety and success of storage projects. Several studies have provided a preliminary assessment of depleted reservoirs as a sequestration practice. However, the screening criteria used in these studies were not able to consider all of the aspects of a storage site. The aim of this paper is to provide a reservoir-scale evaluation approach for long-term storage practice in an offshore carbonate field located in Malaysia. Recently developed screening criteria that cover the key aspects of storage sites, such as capacity, injectivity, trapping mechanisms, and containment, are taken into consideration for the purpose of this study. The results obtained suggest that the reservoir has good potential to be a storage place for CO2, although the compaction behavior and aquifer supports of the reservoir might cause some difficulties. It is, therefore, recommended that a series of experimental and numerical studies on different aspects of storage sites be performed to ensure that injectivity is not a problem when it comes to the implementation stage.

Structural dynamics and vibrations of damped, aircraft-type structures

NASA Technical Reports Server (NTRS)

Young, Maurice I.

1992-01-01

Engineering preliminary design methods for approximating and predicting the effects of viscous or equivalent viscous-type damping treatments on the free and forced vibration of lightly damped aircraft-type structures are developed. Similar developments are presented for dynamic hysteresis viscoelastic-type damping treatments. It is shown by both engineering analysis and numerical illustrations that the intermodal coupling of the undamped modes arising from the introduction of damping may be neglected in applying these preliminary design methods, except when dissimilar modes of these lightly damped, complex aircraft-type structures have identical or nearly identical natural frequencies. In such cases, it is shown that a relatively simple, additional interaction calculation between pairs of modes exhibiting this 'modal response' phenomenon suffices in the prediction of interacting modal damping fractions. The accuracy of the methods is shown to be very good to excellent, depending on the normal natural frequency separation of the system modes, thereby permitting a relatively simple preliminary design approach. This approach is shown to be a natural precursor to elaborate finite element, digital computer design computations in evaluating the type, quantity, and location of damping treatment.

Experiences modeling ocean circulation problems on a 30 node commodity cluster with 3840 GPU processor cores.

NASA Astrophysics Data System (ADS)

Hill, C.

2008-12-01

Low cost graphic cards today use many, relatively simple, compute cores to deliver support for memory bandwidth of more than 100GB/s and theoretical floating point performance of more than 500 GFlop/s. Right now this performance is, however, only accessible to highly parallel algorithm implementations that, (i) can use a hundred or more, 32-bit floating point, concurrently executing cores, (ii) can work with graphics memory that resides on the graphics card side of the graphics bus and (iii) can be partially expressed in a language that can be compiled by a graphics programming tool. In this talk we describe our experiences implementing a complete, but relatively simple, time dependent shallow-water equations simulation targeting a cluster of 30 computers each hosting one graphics card. The implementation takes into account the considerations (i), (ii) and (iii) listed previously. We code our algorithm as a series of numerical kernels. Each kernel is designed to be executed by multiple threads of a single process. Kernels are passed memory blocks to compute over which can be persistent blocks of memory on a graphics card. Each kernel is individually implemented using the NVidia CUDA language but driven from a higher level supervisory code that is almost identical to a standard model driver. The supervisory code controls the overall simulation timestepping, but is written to minimize data transfer between main memory and graphics memory (a massive performance bottle-neck on current systems). Using the recipe outlined we can boost the performance of our cluster by nearly an order of magnitude, relative to the same algorithm executing only on the cluster CPU's. Achieving this performance boost requires that many threads are available to each graphics processor for execution within each numerical kernel and that the simulations working set of data can fit into the graphics card memory. As we describe, this puts interesting upper and lower bounds on the problem sizes for which this technology is currently most useful. However, many interesting problems fit within this envelope. Looking forward, we extrapolate our experience to estimate full-scale ocean model performance and applicability. Finally we describe preliminary hybrid mixed 32-bit and 64-bit experiments with graphics cards that support 64-bit arithmetic, albeit at a lower performance.

Experimental and numerical investigation of the Fast-SAGD process

NASA Astrophysics Data System (ADS)

Shin, Hyundon

The SAGD process has been tested in the field, and is now in a commercial stage in Western Canadian oil sands areas. The Fast-SAGD method can partly solve the drilling difficulty and reduce costs in a SAGD operation requiring paired parallel wells one above the other. This method also enhances the thermal efficiency in the reservoir. In this research, the reservoir parameters and operating conditions for the SAGD and Fast-SAGD processes are investigated by numerical simulation in the three Alberta oil sands areas. Scaled physical model experiments, which are operated by an automated process control system, are conducted under high temperature and high pressure conditions. The results of the study indicate that the shallow Athabasca-type reservoir, which is thick with high permeability (high kxh), is a good candidate for SAGD application, whereas Cold Lake- and Peace River-type reservoirs, which are thin with low permeability, are not as good candidates for conventional SAGD implementation. The simulation results indicate improved energy efficiency and productivity in most cases for the Fast-SAGD process; in those cases, the project economics were enhanced compared to the SAGD process. Both Cold Lake- and Peace River-type reservoirs are good candidates for a Fast-SAGD application rather than a conventional SAGD application. This new process demonstrates improved efficiency and lower costs for extracting heavy oil from these important reservoirs. A new economic indicator, called simple thermal efficiency parameter (STEP), was developed and validated to evaluate the performance of a SAGD project. STEP is based on cumulative steam-oil ratio (CSOR), calendar day oil rate (CDOR) and recovery factor (RF) for the time prior to the steam-oil ratio (SOR) attaining 4. STEP can be used as a financial metric quantitatively as well as qualitatively for this type of thermal project. An automated process control system was set-up and validated, and has the capability of controlling and handling steam injection processes like the steam-assisted gravity drainage process. The results of these preliminary experiments showed the overall cumulative oil production to be larger in the Fast-SAGD case, but end-point CSOR to be lower in the SAGD case. History matching results indicated that the steam quality was as low as 0.3 in the SAGD experiments, and even lower in the Fast-SAGD experiments after starting the CSS.

Anchoring effects in the judgment of confidence: semantic or numeric priming?

PubMed

Carroll, Steven R; Petrusic, William M; Leth-Steensen, Craig

2009-02-01

Over the last decade, researchers have debated whether anchoring effects are the result of semantic or numeric priming. The present study tested both hypotheses. In four experiments involving a sensory detection task, participants first made a relative confidence judgment by deciding whether they were more or less confident than an anchor value in the correctness of their decision. Subsequently, they expressed an absolute level of confidence. In two of these experiments, the relative confidence anchor values represented the midpoints between the absolute confidence scale values, which were either explicitly numeric or semantic, nonnumeric representations of magnitude. In two other experiments, the anchor values were drawn from a scale modally different from that used to express the absolute confidence (i.e., nonnumeric and numeric, respectively, or vice versa). Regardless of the nature of the anchors, the mean confidence ratings revealed anchoring effects only when the relative and absolute confidence values were drawn from identical scales. Together, the results of these four experiments limit the conditions under which both numeric and semantic priming would be expected to lead to anchoring effects.

Numerical simulations of the flow with the prescribed displacement of the airfoil and comparison with experiment

NASA Astrophysics Data System (ADS)

Řidký, V.; Šidlof, P.; Vlček, V.

2013-04-01

The work is devoted to comparing measured data with the results of numerical simulations. As mathematical model was used mathematical model whitout turbulence for incompressible flow In the experiment was observed the behavior of designed NACA0015 airfoil in airflow. For the numerical solution was used OpenFOAM computational package, this is open-source software based on finite volume method. In the numerical solution is prescribed displacement of the airfoil, which corresponds to the experiment. The velocity at a point close to the airfoil surface is compared with the experimental data obtained from interferographic measurements of the velocity field. Numerical solution is computed on a 3D mesh composed of about 1 million ortogonal hexahedron elements. The time step is limited by the Courant number. Parallel computations are run on supercomputers of the CIV at Technical University in Prague (HAL and FOX) and on a computer cluster of the Faculty of Mechatronics of Liberec (HYDRA). Run time is fixed at five periods, the results from the fifth periods and average value for all periods are then be compared with experiment.

Continuum generation in ultra high numerical aperture fiber with application to multiphoton microscopy

NASA Astrophysics Data System (ADS)

Sayler, Nicholas

Nonlinear microscopy benefits from broadband laser sources, enabling efficient excitation of an array of fluorophores, for example. This work demonstrates broadening of a narrow band input pulse (6 nm to 40 nm) centered at 1040 nm with excellent shot-to-shot stability. In a preliminary demonstration, multiphoton imaging with pulses from the fiber is performed. In particular second harmonic imaging of corn starch is performed.

Analytical Qualification of Aircraft Structures: Meeting of the Structures and Materials Panel of AGARD (70th) Held in Sorrento, Italy on 1-6 April 1990 (La Qualification Analytique des Structures d’Avion).

DTIC Science & Technology

1991-04-01

sources of preliminary evalution are the software theor and validation documents. E amination of the theoretical bsis and numerical algorithms, together...knowledge reflected In production models. However, It Is a horror for him to see that production models are composed by stress people who insufficiently

Application of a Fuzzy Verification Technique for Assessment of the Weather Running Estimate-Nowcast (WRE-N) Model

DTIC Science & Technology

2016-10-01

comes when considering numerous scores and statistics during a preliminary evaluation of the applicability of the fuzzy- verification minimum coverage...The selection of thresholds with which to generate categorical-verification scores and statistics from the application of both traditional and...of statistically significant numbers of cases; the latter presents a challenge of limited application for assessment of the forecast models’ ability

Numerical aerodynamic simulation facility preliminary study, volume 2 and appendices

NASA Technical Reports Server (NTRS)

1977-01-01

Data to support results obtained in technology assessment studies are presented. Objectives, starting points, and future study tasks are outlined. Key design issues discussed in appendices include: data allocation, transposition network design, fault tolerance and trustworthiness, logic design, processing element of existing components, number of processors, the host system, alternate data base memory designs, number representation, fast div 521 instruction, architectures, and lockstep array versus synchronizable array machine comparison.

Use of airborne near-infrared LiDAR for determining channel cross-section characteristics and monitoring aquatic habitat in Pacific Northwest rivers: A preliminary analysis [Chapter 6

Treesearch

Russell N. Faux; John M. Buffington; M. German Whitley; Steve H. Lanigan; Brett B. Roper

2009-01-01

Aquatic habitat monitoring is being conducted by numerous organizations in many parts of the Pacific Northwest to document physical and biological conditions of stream reaches as part of legal- and policy-mandated environmental assessments. Remote sensing using discrete-return, near-infrared, airborne LiDAR (Light Detection and Ranging) and high-resolution digital...

Multivariate spline methods in surface fitting

NASA Technical Reports Server (NTRS)

Guseman, L. F., Jr. (Principal Investigator); Schumaker, L. L.

1984-01-01

The use of spline functions in the development of classification algorithms is examined. In particular, a method is formulated for producing spline approximations to bivariate density functions where the density function is decribed by a histogram of measurements. The resulting approximations are then incorporated into a Bayesiaan classification procedure for which the Bayes decision regions and the probability of misclassification is readily computed. Some preliminary numerical results are presented to illustrate the method.

Calculation of plasma dielectric response in inhomogeneous magnetic field near electron cyclotron resonance

NASA Astrophysics Data System (ADS)

Evstatiev, Evstati; Svidzinski, Vladimir; Spencer, Andy; Galkin, Sergei

2014-10-01

Full wave 3-D modeling of RF fields in hot magnetized nonuniform plasma requires calculation of nonlocal conductivity kernel describing the dielectric response of such plasma to the RF field. In many cases, the conductivity kernel is a localized function near the test point which significantly simplifies numerical solution of the full wave 3-D problem. Preliminary results of feasibility analysis of numerical calculation of the conductivity kernel in a 3-D hot nonuniform magnetized plasma in the electron cyclotron frequency range will be reported. This case is relevant to modeling of ECRH in ITER. The kernel is calculated by integrating the linearized Vlasov equation along the unperturbed particle's orbits. Particle's orbits in the nonuniform equilibrium magnetic field are calculated numerically by one of the Runge-Kutta methods. RF electric field is interpolated on a specified grid on which the conductivity kernel is discretized. The resulting integrals in the particle's initial velocity and time are then calculated numerically. Different optimization approaches of the integration are tested in this feasibility analysis. Work is supported by the U.S. DOE SBIR program.

Plasma characteristics in the discharge region of a 20 A emission current hollow cathode

NASA Astrophysics Data System (ADS)

Mingming, SUN; Tianping, ZHANG; Xiaodong, WEN; Weilong, GUO; Jiayao, SONG

2018-02-01

Numerical calculation and fluid simulation methods were used to obtain the plasma characteristics in the discharge region of the LIPS-300 ion thruster’s 20 A emission current hollow cathode and to verify the structural design of the emitter. The results of the two methods indicated that the highest plasma density and electron temperature, which improved significantly in the orifice region, were located in the discharge region of the hollow cathode. The magnitude of plasma density was about 1021 m-3 in the emitter and orifice regions, as obtained by numerical calculations, but decreased exponentially in the plume region with the distance from the orifice exit. Meanwhile, compared to the emitter region, the electron temperature and current improved by about 36% in the orifice region. The hollow cathode performance test results were in good agreement with the numerical calculation results, which proved that that the structural design of the emitter and the orifice met the requirements of a 20 A emission current. The numerical calculation method can be used to estimate plasma characteristics in the preliminary design stage of hollow cathodes.

Comparing the effects of combined numerical and visuo- spatial psychoeducational trainings conducted by curricular teachers and external trainers. Preliminary evidence across kindergarteners.

NASA Astrophysics Data System (ADS)

Agus, M.; Mascia, M. L.; Fastame, M. C.; Napoleone, V.; Porru, A. M.; Siddu, F.; Lucangeli, D.; Penna, M. P.

2016-11-01

The aim of this study was to verify the efficacy of two pencil-and-paper trainings empowering numerical and visuo-spatial abilities in Italian five-year-old kindergarteners. Specifically, the trainings were respectively carried out by the curricular teacher or by an external trainer. The former received a specific training in order to use the psychoeducational programmes with her pupils, whereas the latter received a specific education about the role of numerical and visuo-spatial abilities for school achievement and she was also trained to use psychoeducational trainings in kindergarten schools. At pre-test and post-test nonverbal functions and numeracy knowledge were assessed through a battery of standardized tests. The results show that both the numerical psychoeducational programme and the visuo-spatial one are useful tools to enhance mathematical achievements in kindergarteners. However, when the trainings were proposed by the external trainer, the efficacy of the psychoeducational programmes was more significant. These outcomes seem to be related both to the expertise and the novelty effect of the external trainer on the classroom.

Numerical method for the solution of large systems of differential equations of the boundary layer type

NASA Technical Reports Server (NTRS)

Green, M. J.; Nachtsheim, P. R.

1972-01-01

A numerical method for the solution of large systems of nonlinear differential equations of the boundary-layer type is described. The method is a modification of the technique for satisfying asymptotic boundary conditions. The present method employs inverse interpolation instead of the Newton method to adjust the initial conditions of the related initial-value problem. This eliminates the so-called perturbation equations. The elimination of the perturbation equations not only reduces the user's preliminary work in the application of the method, but also reduces the number of time-consuming initial-value problems to be numerically solved at each iteration. For further ease of application, the solution of the overdetermined system for the unknown initial conditions is obtained automatically by applying Golub's linear least-squares algorithm. The relative ease of application of the proposed numerical method increases directly as the order of the differential-equation system increases. Hence, the method is especially attractive for the solution of large-order systems. After the method is described, it is applied to a fifth-order problem from boundary-layer theory.

Trees, bialgebras and intrinsic numerical algorithms

NASA Technical Reports Server (NTRS)

Crouch, Peter; Grossman, Robert; Larson, Richard

1990-01-01

Preliminary work about intrinsic numerical integrators evolving on groups is described. Fix a finite dimensional Lie group G; let g denote its Lie algebra, and let Y(sub 1),...,Y(sub N) denote a basis of g. A class of numerical algorithms is presented that approximate solutions to differential equations evolving on G of the form: dot-x(t) = F(x(t)), x(0) = p is an element of G. The algorithms depend upon constants c(sub i) and c(sub ij), for i = 1,...,k and j is less than i. The algorithms have the property that if the algorithm starts on the group, then it remains on the group. In addition, they also have the property that if G is the abelian group R(N), then the algorithm becomes the classical Runge-Kutta algorithm. The Cayley algebra generated by labeled, ordered trees is used to generate the equations that the coefficients c(sub i) and c(sub ij) must satisfy in order for the algorithm to yield an rth order numerical integrator and to analyze the resulting algorithms.

Experimental and numerical analysis of pre-compressed masonry walls in two-way-bending with second order effects

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

Milani, Gabriele, E-mail: milani@stru.polimi.it; Olivito, Renato S.; Tralli, Antonio

2014-10-06

The buckling behavior of slender unreinforced masonry (URM) walls subjected to axial compression and out-of-plane lateral loads is investigated through a combined experimental and numerical homogenizedapproach. After a preliminary analysis performed on a unit cell meshed by means of elastic FEs and non-linear interfaces, macroscopic moment-curvature diagrams so obtained are implemented at a structural level, discretizing masonry by means of rigid triangular elements and non-linear interfaces. The non-linear incremental response of the structure is accounted for a specific quadratic programming routine. In parallel, a wide experimental campaign is conducted on walls in two way bending, with the double aim ofmore » both validating the numerical model and investigating the behavior of walls that may not be reduced to simple cantilevers or simply supported beams. Panels investigated are dry-joint in scale square walls simply supported at the base and on a vertical edge, exhibiting the classical Rondelet’s mechanism. The results obtained are compared with those provided by the numerical model.« less

Addicted to Pain: A Preliminary Model of Sexual Masochism as Addiction.

PubMed

Kurt, Holly; Ronel, Natti

2017-11-01

An exploratory, qualitative, phenomenological study focused on the experience of pain while participating in sexual masochistic acts. Semi-structured interviews were conducted with nine individuals (four female, five male) who regularly participate in sexually masochistic acts and point to pain as central to their experience. Qualitative analysis of the data revealed several key characteristics of the participant's experience: the first time, intoxication, craving and withdrawal, tolerance, pain as control, and the pain inducing partner. The findings indicate that the way pain is experienced while mitigated through masochistic behavior creates an addictive process that coincides with a chronic behavioral spin contextualization. This article presents a preliminary model of addiction to physical pain in light of the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) definition of substance-related and addictive disorders and the behavioral spin theory.

Preliminary results on noncollocated torque control of space robot actuators

NASA Technical Reports Server (NTRS)

Tilley, Scott W.; Francis, Colin M.; Emerick, Ken; Hollars, Michael G.

1989-01-01

In the Space Station era, more operations will be performed robotically in space in the areas of servicing, assembly, and experiment tending among others. These robots may have various sets of requirements for accuracy, speed, and force generation, but there will be design constraints such as size, mass, and power dissipation limits. For actuation, a leading motor candidate is a dc brushless type, and there are numerous potential drive trains each with its own advantages and disadvantages. This experiment uses a harmonic drive and addresses some inherent limitations, namely its backdriveability and low frequency structural resonances. These effects are controlled and diminished by instrumenting the actuator system with a torque transducer on the output shaft. This noncollocated loop is closed to ensure that the commanded torque is accurately delivered to the manipulator link. The actuator system is modelled and its essential parameters identified. The nonlinear model for simulations will include inertias, gearing, stiction, flexibility, and the effects of output load variations. A linear model is extracted and used for designing the noncollocated torque and position feedback loops. These loops are simulated with the structural frequency encountered in the testbed system. Simulation results are given for various commands in position. The use of torque feedback is demonstrated to yield superior performance in settling time and positioning accuracy. An experimental setup being finished consists of a bench mounted motor and harmonic drive actuator system. A torque transducer and two position encoders, each with sufficient resolution and bandwidth, will provide sensory information. Parameters of the physical system are being identified and matched to analytical predictions. Initial feedback control laws will be incorporated in the bench test equipment and various experiments run to validate the designs. The status of these experiments is given.

Modelling of vegetation-driven morphodynamics in braided rivers.

NASA Astrophysics Data System (ADS)

Stecca, Guglielmo; Fedrizzi, Davide; Hicks, Murray; Measures, Richard; Zolezzi, Guido; Bertoldi, Walter; Tal, Michal

2017-04-01

River planform results from the complex interaction between flow, sediment transport and vegetation, and can evolve following a change in these controls. The braided planform of New Zealand's Lower Waitaki River, for instance, is endangered by the action of artificially-introduced alien vegetation, which spread across the braidplain following the reduction in magnitude of floods by hydropower dam construction. This vegetation, by encouraging flow concentration into the main channel, would likely promote a shift towards a single-thread morphology if it was not artificially removed within a central fairway. The purpose of this work is to study the evolution of braided rivers such as the Waitaki under different management scenarios through two-dimensional numerical modelling. The construction of a suitable model represents a task in itself, since a modelling framework coupling all the relevant processes is not yet readily available. Our starting point is the physics-based GIAMT2D numerical model, which solves two-dimensional flow and bedload transport in wet/dry domains, and recently modified by the inclusion of a rule-based bank erosion model. We have further developed this model by adding a vegetation module, which accounts in a simplified manner for time-evolving biomass density, adjusting local flow roughness, critical shear stress for sediment transport, and bank erodibility accordingly. Our goal is to use the model to study decadal-scale evolution of a reach on the Waitaki River and predict planform characteristics under different vegetation management scenarios. Here we present the results of a preliminary application of the model to reproduce the morphodynamic evolution of a braided channel in a set of flume experiments that used alfalfa as vegetation. The experiments began with a braided morphology that spontaneoulsy formed at constant flow over a bed of bare uniform sand. The planform transitioned towards single-thread when this discharge was repeatedly cycled with periods of low flow and vegetation growth.

Aerodynamic effects of trees on pollutant concentration in street canyons.

PubMed

Buccolieri, Riccardo; Gromke, Christof; Di Sabatino, Silvana; Ruck, Bodo

2009-09-15

This paper deals with aerodynamic effects of avenue-like tree planting on flow and traffic-originated pollutant dispersion in urban street canyons by means of wind tunnel experiments and numerical simulations. Several parameters affecting pedestrian level concentration are investigated, namely plant morphology, positioning and arrangement. We extend our previous work in this novel aspect of research to new configurations which comprise tree planting of different crown porosity and stand density, planted in two rows within a canyon of street width to building height ratio W/H=2 with perpendicular approaching wind. Sulfur hexafluoride was used as tracer gas to model the traffic emissions. Complementary to wind tunnel experiments, 3D numerical simulations were performed with the Computational Fluid Dynamics (CFD) code FLUENT using a Reynolds Stress turbulence closure for flow and the advection-diffusion method for concentration calculations. In the presence of trees, both measurements and simulations showed considerable larger pollutant concentrations near the leeward wall and slightly lower concentrations near the windward wall in comparison with the tree-less case. Tree stand density and crown porosity were found to be of minor importance in affecting pollutant concentration. On the other hand, the analysis indicated that W/H is a more crucial parameter. The larger the value of W/H the smaller is the effect of trees on pedestrian level concentration regardless of tree morphology and arrangement. A preliminary analysis of approaching flow velocities showed that at low wind speed the effect of trees on concentrations is worst than at higher speed. The investigations carried out in this work allowed us to set up an appropriate CFD modelling methodology for the study of the aerodynamic effects of tree planting in street canyons. The results obtained can be used by city planners for the design of tree planting in the urban environment with regard to air quality issues.

Special Education Paraprofessionals in District Context

ERIC Educational Resources Information Center

Howley, Craig; Howley, Aimee; Telfer, Deborah

2017-01-01

This survey research investigated the experience of Ohio districts using paraprofessionals assigned to special education students. This study provides a unique statewide description of district experience. Based on themes from the literature and preliminary conversations with educational practitioners in Ohio, the survey conceptualized district…

Thermal Gradient Fining of Glass

NASA Technical Reports Server (NTRS)

Wilcox, W.

1983-01-01

Molten glass fined (cleared of bubbles) by heating with suitable temperature gradient, according to preliminary experiments. Temperature gradient produces force on gas bubbles trapped in molten glass pushing bubbles to higher temperature region where they are collected. Concept demonstrated in experiments on Earth and on rocket.

Experiences of four parents with physical therapy and early mobility of their children in a pediatric critical care unit: A case series.

PubMed

Parisien, Rachel B; Gillanders, Kirstie; Hennessy, Erin K; Herterich, Lisa; Saunders, Kendra; Lati, Jamil; Dos Santos, Stephanie; Hassall, Alison; O'Brien, Kelly K

2016-05-31

The aim of this study was to conduct a preliminary investigation into parents' experiences of physical therapy and early mobility (EM) for their children in a pediatric critical care unit (PCCU). We conducted a series of four qualitative case studies using in-depth semi-structured face-to-face interviews. We recruited parents of children who had undergone surgery and received at least one EM physical therapy intervention while intubated. We conducted a thematic analysis of transcribed interviews to illuminate the factors that influenced EM experiences. Four parents participated in the study. We developed an overview of Parental Experiences with Physical Therapy and Early Mobility in a PCCU, which includes four themes that parents believed influenced their experiences: (1) environmental factors; (2) awareness of physical therapist and health care professional (HCP) roles; (3) communication among parents and HCPs; and (4) parental participation in their child's EM, within the overarching parental experiences in the PCCU. This study affords a preliminary understanding of parents' experiences with physical therapy and EM in a PCCU setting. Results provide an important foundation for future research on mobility in the context of pediatric critical care research and practice.

Quantifying a threat: Evidence of a numeric processing bias.

PubMed

Hamamouche, Karina A; Niemi, Laura; Cordes, Sara

2017-06-01

Humans prioritize the processing of threats over neutral stimuli; thus, not surprisingly, the presence of threats has been shown to alter performance on both perceptual and cognitive tasks. Yet whether the quantification process is disrupted in the presence of threat is unknown. In three experiments, we examined numerical estimation and discrimination abilities in adults in the context of threatening (spiders) and non-threatening (e.g., flowers) stimuli. Results of the numerical estimation task (Experiment 1) showed that participants underestimated the number of threatening relative to neutral stimuli. Additionally, numerical discrimination data reveal that participants' abilities to discriminate between the number of entities in two arrays were worsened when the arrays consisted of threatening entities versus neutral entities (Experiment 2). However, discrimination abilities were enhanced when threatening content was presented immediately before neutral dot arrays (Experiment 3). Together, these studies suggest that threats impact our processing of visual numerosity via changes in attention to numerical stimuli, and that the nature of the threat (intrinsic or extrinsic to the stimulus) is vital in determining the direction of this impact. Intrinsic threat content in stimuli impedes its own quantification; yet threat that is extrinsic to the sets to be enumerated enhances numerical processing for subsequently presented neutral stimuli. Copyright © 2017 Elsevier B.V. All rights reserved.

Low-cost 420nm blue laser diode for tissue cutting and hemostasis

NASA Astrophysics Data System (ADS)

Linden, Kurt J.

2016-03-01

This paper describes the use of a 420 nm blue laser diode for possible surgery and hemostasis. The optical absorption of blood-containing tissue is strongly determined by the absorption characteristics of blood. Blood is primarily comprised of plasma (yellowish extracellular fluid that is approximately 95% water by volume) and formed elements: red blood cells (RBCs), white blood cells (WBCs) and platelets. The RBCs (hemoglobin) are the most numerous, and due to the spectral absorption characteristics of hemoglobin, the optical absorption of blood has a strong relative maximum value in the 420 nm blue region of the optical spectrum. Small, low-cost laser diodes emitting at 420 nm with tens of watts of continuous wave (CW) optical power are becoming commercially available. Experiments on the use of such laser diodes for tissue cutting with simultaneous hemostasis were carried out and are here described. It was found that 1 mm deep x 1 mm wide cuts can be achieved in red meat at a focused laser power level of 3 W moving at a velocity of ~ 1 mm/s. The peripheral necrosis and thermal damage zone extended over a width of approximately 0.5 mm adjacent to the cuts. Preliminary hemostasis experiments were carried out with fresh equine blood in Tygon tubing, where it was demonstrated that cauterization can occur in regions of intentional partial tubing puncture.