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1

Experimental results from CERN on reaction mechanisms in high energy heavy ion collisions  

SciTech Connect

Three main experimental results from CERN concerning reaction mechanisms in high energy heavy ion collisions are discussed: (1) the striking validity of the single particle picture, (2) the nuclear stopping power and (3) the attained energy densities.

Sorensen, S.P. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA). Dept. of Physics)

1990-01-01

2

High energy imploding liner experiment HEL-1: Experimental results  

SciTech Connect

Magnetically driven imploding liner systems can be used as a source of shock energy for materials equation of state studies, implosion driven magnetized plasma fusion experiments, and other similar applications. The imploding liner is a cylinder of conducting material through which a current is passed in the longitudinal direction. Interaction of the current with its own magnetic field causes the liner to implode. Sources of electrical energy for imploding liner systems are capacitor banks or explosive pulse power systems seeded by capacitor banks. In August, 1996, a high energy liner experiment (HEL-1) was conducted at the All-Russia Scientific Research Institute (VNIIEF) in Sarov, Russia. A 5 tier 1 meter diameter explosive disk generator provided electrical energy to drive a 48 cm outside diameter, 4 mm thick, aluminum alloy liner having a mass of about 11kg onto an 11 cm diameter diagnostic package. The purpose of the experiment was to measure performance of the explosive pulse power generator and the heavy imploding liner. Electrical performance diagnostics included inductive (B-dot) probes, Faraday Rotation current measurement, Rogowski total current measurement, and voltage probes. Flux loss and conductor motion diagnostics included current-joint voltage measurements and motion sensing contact pins. Optical and electrical impact pins, inductive (B-dot) probes, manganin pressure probes, and continuously recording resistance probes in the Central Measuring Unit (CMU) and Piezo and manganin pressure probes, optical beam breakers, and inductive probes located in the glide planes were used as liner symmetry and velocity diagnostics. Preliminary analysis of the data indicate that a peak current of more than 100 MA was attained and the liner velocity was between 6.7 km/sec and 7.5 km/sec. Liner kinetic energy was between 22 MJ and 35 MJ. 4 refs., 6 figs., 1 tab.

Clark, D.A.; Anderson, B.G.; Ekdahl, C.A. [and others

1997-09-01

3

Preliminary results of the large experimental wind turbine phase of the national wind energy program  

Microsoft Academic Search

The preliminary results of two projects in the development phase of reliable wind turbines designed to supply cost-competitive electrical energy were discussed. An experimental 100 kW wind turbine design and its status are first reviewed. The results of two parallel design studies for determining the configurations and power levels for wind turbines with minimum energy costs are also discussed. These

R. L. Thomas; T. Sholes; J. E. Sholes

1975-01-01

4

Modifications of the high-energy transport code (HETC) and comparisons with experimental results  

SciTech Connect

The High-Energy Transport Code HETC has been revised by incorporating a multi-chain fragmentation model to describe particle production from high-energy hadron-nucleus collisions. The revised code is briefly described and its validity is tested by comparing calculated results with experimental data from 29.4 GeV protons incident on an iron-air beam stop and with experimental data from 800 GeV protons incident on a large iron block. Some comparisons with calculated results obtained with other available transport codes; FLUKA82, CASIM, and MARS10 are also included. 18 refs., 3 figs.

Alsmiller, R.G. Jr.; Alsmiller, F.S.; Gabriel, T.A.; Hermann, O.W.

1987-01-01

5

Comparison of energy deposition calculations by the LAHET Code System with experimental results  

SciTech Connect

A comparison was performed between the energy deposition predicted by the LAHET Code System (LCS) with experimental values determined by Belyakov-Bodin et al. for 800, 1000, and 1200 MeV protons on targets composed of lead, bismuth, beryllium, carbon, and aluminum. The lead and bismuth showed agreement within approximately 10% at locations throughout the targets, and the agreement of the total energy deposited over the axial length of the targets ranged from 1% to 25%. For the lead and bismuth cases, the LCS predictions were always greater than the experimental results. For the lighter materials, the agreement at locations throughout the target only agreed within approximately 20%. No definable trend could be determined for the lighter materials since some LCS predictions were greater than the experimental results, some were less than the experimental results, and some showed very good agreement. The total energy deposited over the axial length of the targets was not compared for the lighter materials since it was not explicitly given with the experimental data.

Beard, C.A.; Lisowski, P.W.; Russell, G.J.; Waters, L.S.

1993-08-01

6

Preliminary results of the large experimental wind turbine phase of the national wind energy program  

NASA Technical Reports Server (NTRS)

The preliminary results of two projects in the development phase of reliable wind turbines designed to supply cost-competitive electrical energy were discussed. An experimental 100 kW wind turbine design and its status are first reviewed. The results of two parallel design studies for determining the configurations and power levels for wind turbines with minimum energy costs are also discussed. These studies predict wind energy costs of 1.5 to 7 cents per kW-h for wind turbines produced in quantities of 100 to 1000 per year and located at sites having average winds of 12 to 18 mph.

Thomas, R. L.; Sholes, T.; Sholes, J. E.

1975-01-01

7

Experimental Results From the Thermal Energy Storage-1 (TES-1) Flight Experiment  

NASA Technical Reports Server (NTRS)

The Thermal Energy Storage (TES) experiments are designed to provide data to help researchers understand the long-duration microgravity behavior of thermal energy storage fluoride salts that undergo repeated melting and freezing. Such data, which have never been obtained before, have direct application to space-based solar dynamic power systems. These power systems will store solar energy in a thermal energy salt, such as lithium fluoride (LiF) or a eutectic of lithium fluoride/calcium difluoride (LiF-CaF2) (which melts at a lower temperature). The energy will be stored as the latent heat of fusion when the salt is melted by absorbing solar thermal energy. The stored energy will then be extracted during the shade portion of the orbit, enabling the solar dynamic power system to provide constant electrical power over the entire orbit. Analytical computer codes have been developed to predict the performance of a spacebased solar dynamic power system. However, the analytical predictions must be verified experimentally before the analytical results can be used for future space power design applications. Four TES flight experiments will be used to obtain the needed experimental data. This article focuses on the flight results from the first experiment, TES-1, in comparison to the predicted results from the Thermal Energy Storage Simulation (TESSIM) analytical computer code.

Jacqmin, David

1995-01-01

8

Preliminary results of the large experimental wind turbine phase of the national wind energy program  

NASA Technical Reports Server (NTRS)

A major phase of the wind energy program is the development of reliable wind turbines for supplying cost-competitive electrical energy. This paper discusses the preliminary results of two projects in this phase of the program. First an experimental 100 kW wind turbine design and its status are reviewed. Also discussed are the results of two parallel design studies for determining the configurations and power levels for wind turbines with minimum energy costs. These studies show wind energy costs of 7 to 1.5 c/kWH for wind turbines produced in quantities of 100 to 1000 a year and located at sites having average winds of 12 to 18 mph.

Thomas, R. L.; Sholes, J. E.

1975-01-01

9

Optimal piezoelectric beam shape for single and broadband vibration energy harvesting: Modeling, simulation and experimental results  

NASA Astrophysics Data System (ADS)

Harvesting energy from the surroundings has become a new trend in saving our environment. Among the established ones are solar panels, wind turbines and hydroelectric generators which have successfully grown in meeting the world's energy demand. However, for low powered electronic devices; especially when being placed in a remote area, micro scale energy harvesting is preferable. One of the popular methods is via vibration energy scavenging which converts mechanical energy (from vibration) to electrical energy by the effect of coupling between mechanical variables and electric or magnetic fields. As the voltage generated greatly depends on the geometry and size of the piezoelectric material, there is a need to define an optimum shape and configuration of the piezoelectric energy scavenger. In this research, mathematical derivations for unimorph piezoelectric energy harvester are presented. Simulation is done using MATLAB and COMSOL Multiphysics software to study the effect of varying the length and shape of the beam to the generated voltage. Experimental results comparing triangular and rectangular shaped piezoelectric beam are also presented.

Muthalif, Asan G. A.; Nordin, N. H. Diyana

2015-03-01

10

Experimental Results from the Thermal Energy Storage-1 (TES-1) Flight Experiment  

NASA Technical Reports Server (NTRS)

The Thermal Energy Storage-1 (TES-1) is a flight experiment that flew on the Space Shuttle Columbia (STS-62), in March 1994, as part of the OAST-2 mission. TES-1 is the first experiment in a four experiment suite designed to provide data for understanding the long duration microgravity behavior of thermal energy storage fluoride salts that undergo repeated melting and freezing. Such data have never been obtained before and have direct application for the development of space-based solar dynamic (SD) power systems. These power systems will store solar energy in a thermal energy salt such as lithium fluoride or calcium fluoride. The stored energy is extracted during the shade portion of the orbit. This enables the solar dynamic power system to provide constant electrical power over the entire orbit. Analytical computer codes have been developed for predicting performance of a spaced-based solar dynamic power system. Experimental verification of the analytical predictions is needed prior to using the analytical results for future space power design applications. The four TES flight experiments will be used to obtain the needed experimental data. This paper will focus on the flight results from the first experiment, TES-1, in comparison to the predicted results from the Thermal Energy Storage Simulation (TESSIM) analytical computer code. The TES-1 conceptual development, hardware design, final development, and system verification testing were accomplished at the NASA lewis Research Center (LeRC). TES-1 was developed under the In-Space Technology Experiment Program (IN-STEP), which sponsors NASA, industry, and university flight experiments designed to enable and enhance space flight technology. The IN-STEP Program is sponsored by the Office of Space Access and Technology (OSAT).

Wald, Lawrence W.; Tolbert, Carol; Jacqmin, David

1995-01-01

11

Experimental Results on Diffraction  

E-print Network

Experimental Results on Diffraction Hadron Collider Physics Symposium May 28, 2008 Pierre Van Mechelen Pierre.VanMechelen@ua.ac.be #12;Pierre Van Mechelen - Experimental Results on Diffraction - Hadron Collider Physics Symposium -- May 28, 2008 2 Outline b, W, b, W, H Diffractive processes and kinematics

12

Experimental Estimation Of Energy Damping During Free Rocking Of Unreinforced Masonry Walls. First Results  

NASA Astrophysics Data System (ADS)

This paper presents an ongoing experimental program on unreinforced masonry walls undergoing free rocking. Aim of the laboratory campaign is the estimation of kinetic energy damping exhibited by walls released with non-zero initial conditions of motion. Such energy damping is necessary for dynamic modelling of unreinforced masonry local mechanisms. After a brief review of the literature on this topic, the main features of the laboratory tests are presented. The program involves the experimental investigation of several parameters: 1) unit material (brick or tuff), 2) wall aspect ratio (ranging between 14.5 and 7.1), 3) restraint condition (two-sided or one-sided rocking), and 4) depth of the contact surface between façade and transverse walls (one-sided rocking only). All walls are single wythe and the mortar is pozzuolanic. The campaign is still in progress. However, it is possible to present the results on most of the mechanical properties of mortar and bricks. Moreover, a few time histories are reported, already indicating the need to correct some of the assumptions frequent in the literature.

Sorrentino, Luigi; Masiani, Renato; Benedetti, Stefano

2008-07-01

13

Experimental Results from the Thermal Energy Storage-2 (TES-2) Flight Experiment  

NASA Technical Reports Server (NTRS)

Thermal Energy Storage-2 (TES-2) is a flight experiment that flew on the Space Shuttle Endeavour (STS-72), in January 1996. TES-2 originally flew with TES-1 as part of the OAST-2 Hitchhiker payload on the Space Shuttle Columbia (STS-62) in early 1994. The two experiments, TES-1 and TES-2 were identical except for the fluoride salts to be characterized. TES-1 provided data on lithium fluoride (LiF), TES-2 provided data on a fluoride eutectic (LiF/CaF2). Each experiment was a complex autonomous payload in a Get-Away-Special payload canister. TES-1 operated flawlessly for 22 hr. Results were reported in a paper entitled, Effect of Microgravity on Materials Undergoing Melting and Freezing-The TES Experiment, by David Namkoong et al. A software failure in TES-2 caused its shutdown after 4 sec of operation. TES-1 and 2 were the first experiments in a four experiment suite designed to provide data for understanding the long duration microgravity behavior of thermal energy storage salts that undergo repeated melting and freezing. Such data have never been obtained before and have direct application for the development of space-based solar dynamic (SD) power systems. These power systems will store energy in a thermal energy salt such as lithium fluoride or a eutectic of lithium fluoride/calcium difluoride. The stored energy is extracted during the shade portion of the orbit. This enables the solar dynamic power system to provide constant electrical power over the entire orbit. Analytical computer codes were developed for predicting performance of a space-based solar dynamic power system. Experimental verification of the analytical predictions were needed prior to using the analytical results for future space power design applications. The four TES flight experiments were to be used to obtain the needed experimental data. This paper will address the flight results from the first and second experiments, TES-1 and 2, in comparison to the predicted results from the Thermal Energy Storage Simulation (TESSIM) analytical computer code. An analysis of the TES-2 data was conducted by Cleveland State University Professor, Mounir Ibrahim. TESSIM validation was based on two types of results; temperature history of various points on the containment vessel and TES material distribution within the vessel upon return from flight. The TESSIM prediction showed close comparison with the flight data. Distribution of the TES material within the vessel was obtained by a tomography imaging process. The frozen TES material was concentrated toward the colder end of the canister. The TESSIM prediction indicated a similar pattern. With agreement between TESSIM and the flight data, a computerized representation was produced to show the movement and behavior of the void during the entire melting and freezing cycles.

Tolbert, Carol

2000-01-01

14

Experimental results from RO-PRO: a next generation system for low-energy desalination.  

PubMed

A pilot system was designed and constructed to evaluate reverse osmosis (RO) energy reduction that can be achieved using pressure-retarded osmosis (PRO). The RO-PRO experimental system is the first known system to utilize energy from a volume of water transferred from atmospheric pressure to elevated pressure across a semipermeable membrane to prepressurize RO feedwater. In other words, the system demonstrated that pressure could be exchanged between PRO and RO subsystems. Additionally, the first experimental power density data for a RO-PRO system is now available. Average experimental power densities for the RO-PRO system ranged from 1.1 to 2.3 W/m2. This is higher than previous river-to-sea PRO pilot systems (1.5 W/m2) and closer to the goal of 5 W/m2 that would make PRO an economically feasible technology. Furthermore, isolated PRO system testing was performed to evaluate PRO element performance with higher cross-flow velocities and power densities exceeding 8 W/m2 were achieved with a 28 g/L NaCl draw solution. From this empirical data, inferences for future system performance can be drawn that indicate future RO-PRO systems may reduce the specific energy requirements for desalination by ?1 kWh/m3. PMID:24798068

Achilli, Andrea; Prante, Jeri L; Hancock, Nathan T; Maxwell, Eric B; Childress, Amy E

2014-06-01

15

Multigan: First experimental results  

SciTech Connect

A new design of a multicharged ion source based on the MONO1000 ECRIS has been presented at the last ECR ion source (ECRIS) Workshop 2010. [L. Maunoury et al., in Proceedings of the XIXth International Workshop on ECR Ion Sources, Grenoble, France, 23-26 August 2010] This source has not only two opening at both ends but also a large space in the middle of the source enabling a direct contact with the ECR plasma. The source has been assembled mechanically and put on a test bench at the Pantechnik company. The primary tests have shown that the plasma ignition occurred at low pressure (10{sup -6} mbar) and low RF power (10 W). The first experimental results (= 1.30 for Ar and 1.85 for Xe) demonstrated the potential of this ion source in production of multicharged ion beams.

Maunoury, L.; Pacquet, J. Y.; Baret, P.; Dubois, M.; Leherissier, P.; Michel, M. [GANIL, bd H. Becquerel BP 55027, F-14076 Caen cedex 05 (France); Donzel, X.; Gaubert, G.; Leroy, R.; Villarit, A. C. C. [PANTECHNIK, 13 rue de la resistance, F-14400 Bayeux (France)

2012-02-15

16

Simulation of energy barrier distributions using real particle parameters and comparison with experimental obtained results  

NASA Astrophysics Data System (ADS)

Distributions of energy barriers in systems of magnetic nanoparticles have been calculated by means of the path integral method and the results have been compared with distributions previously obtained in our experiments by means of the temperature dependent magnetorelaxation method. The path integral method allowed to obtain energies of the interactions of magnetic moments of nanoparticles with axes of their easy magnetisation as well as energies of mutual interactions of magnetic moments. Calculated distributions of energy barriers have been described satisfactorily by curves of the lognormal distribution. We found an agreement between the theory and the experiment at temperatures above approximately 100 K. The influence of the volume concentration of nanoparticles and agglomeration on the energy barrier distribution has been investigated.

Büttner, M.; Schiffler, M.; Weber, P.; Seidel, P.

2013-11-01

17

Experimental results from wave tank trials of a multi-axis wave energy converter  

NASA Astrophysics Data System (ADS)

A 1/64th scale prototype of multi-axis wave energy converter (WEC) has been tested in the wave tank and the overall concept has been verified. It is shown that when multiple directions of motion are involved, the multi-axis WEC proves to be able to supply more power generation than a single axis one. Results demonstrated that the optimal resonant frequency for maximum power output under different damping values does not vary with wave climate. It is also shown that large overload capability of the system is critical, and indicated that, electric power system is essential to reduce power fluctuations.

Zhang, Dahai; Aggidis, George; Wang, Yifei; Mccabe, Andy; Li, Wei

2013-09-01

18

Validation and verification of MCNP6 against intermediate and high-energy experimental data and results by other codes  

Microsoft Academic Search

MCNP6, the latest and most advanced LANL transport code representing a recent merger of MCNP5 and MCNPX, has been Validated\\u000a and Verified (V&V) against a variety of intermediate and high-energy experimental data and against results by different versions\\u000a of MCNPX and other codes. In the present work, we V&V MCNP6 using mainly the latest modifications of the Cascade-Exciton Model\\u000a (CEM)

S. G. Mashnik

2011-01-01

19

Validation and verification of MCNP6 against intermediate and high-energy experimental data and results by other codes  

Microsoft Academic Search

MCNP6, the latest and most advanced LANL transport code representing a recent merger of MCNP5 and MCNPX, has been Validated and Verified (V&V) against a variety of intermediate and high-energy experimental data and against results by different versions of MCNPX and other codes. In the present work, we V&V MCNP6 using mainly the latest modifications of the Cascade-Exciton Model (CEM)

S. G. Mashnik

2011-01-01

20

Validation and verification of MCNP6 against intermediate and high-energy experimental data and results by other codes  

Microsoft Academic Search

MCNP6, the latest and most advanced LANL transport code representing a recent merger of MCNP5 and MCNPX, has been Validated and Verified (V and V) against a variety of intermediate and high-energy experimental data and against results by different versions of MCNPX and other codes. In the present work, we V andV MCNP6 using mainly the latest modifications of the

Stepan G. Mashnik; Stepan G

2010-01-01

21

Experimental Results on Diffraction  

E-print Network

Results on diffractive scattering observed at HERA and at the TEVATRON are reviewed. This includes the extraction of diffractive parton density functions and determination of the rapidity gap survival probability at HERA and the observation of central exclusive production of final states at the TEVATRON. Finally, preparations to observe diffractive signals at the LHC are discussed.

Pierre Van Mechelen

2008-08-05

22

Validation and Verification of MCNP6 Against Intermediate and High-Energy Experimental Data and Results by Other Codes  

E-print Network

MCNP6, the latest and most advanced LANL transport code representing a recent merger of MCNP5 and MCNPX, has been Validated and Verified (V&V) against a variety of intermediate and high-energy experimental data and against results by different versions of MCNPX and other codes. In the present work, we V&V MCNP6 using mainly the latest modifications of the Cascade-Exciton Model (CEM) and of the Los Alamos version of the Quark-Gluon String Model (LAQGSM) event generators CEM03.02 and LAQGSM03.03. We found that MCNP6 describes reasonably well various reactions induced by particles and nuclei at incident energies from 18 MeV to about 1 TeV per nucleon measured on thin and thick targets and agrees very well with similar results obtained with MCNPX and calculations by CEM03.02, LAQGSM03.01 (03.03), INCL4 + ABLA, and Bertini INC + Dresner evaporation, EPAX, ABRABLA, HIPSE, and AMD, used as stand alone codes. Most of several computational bugs and more serious physics problems observed in MCNP6/X during our V...

Mashnik, Stepan G

2010-01-01

23

Validation and Verification of MCNP6 Against Intermediate and High-Energy Experimental Data and Results by Other Codes  

E-print Network

MCNP6, the latest and most advanced LANL transport code representing a recent merger of MCNP5 and MCNPX, has been Validated and Verified (V&V) against a variety of intermediate and high-energy experimental data and against results by different versions of MCNPX and other codes. In the present work, we V&V MCNP6 using mainly the latest modifications of the Cascade-Exciton Model (CEM) and of the Los Alamos version of the Quark-Gluon String Model (LAQGSM) event generators CEM03.02 and LAQGSM03.03. We found that MCNP6 describes reasonably well various reactions induced by particles and nuclei at incident energies from 18 MeV to about 1 TeV per nucleon measured on thin and thick targets and agrees very well with similar results obtained with MCNPX and calculations by CEM03.02, LAQGSM03.01 (03.03), INCL4 + ABLA, and Bertini INC + Dresner evaporation, EPAX, ABRABLA, HIPSE, and AMD, used as stand alone codes. Most of several computational bugs and more serious physics problems observed in MCNP6/X during our V&V have been fixed; we continue our work to solve all the known problems before MCNP6 is distributed to the public.

Stepan G. Mashnik

2011-05-26

24

Validation and verification of MCNP6 against intermediate and high-energy experimental data and results by other codes  

NASA Astrophysics Data System (ADS)

MCNP6, the latest and most advanced LANL transport code representing a recent merger of MCNP5 and MCNPX, has been Validated and Verified (V&V) against a variety of intermediate and high-energy experimental data and against results by different versions of MCNPX and other codes. In the present work, we V&V MCNP6 using mainly the latest modifications of the Cascade-Exciton Model (CEM) and of the Los Alamos version of the Quark-Gluon String Model (LAQGSM) event generators CEM03.03 and LAQGSM03.03. We found that MCNP6 describes reasonably well various reactions induced by particles and nuclei at incident energies from 18MeV to about 1TeV per nucleon measured on thin and thick targets and agrees very well with similar results obtained with MCNPX and calculations by CEM03.03, LAQGSM03.03 (03.01), INCL4 + ABLA, and Bertini INC + Dresner evaporation, EPAX, ABRABLA, HIPSE, and AMD, used as stand-alone codes. Most of several computational bugs and more serious physics problems observed in MCNP6/X during our V&V have been fixed; we continue our work to solve all the known problems before MCNP6 is distributed to the public.

Mashnik, S. G.

2011-05-01

25

CDF experimental results on diffraction  

E-print Network

Experimental results on diffraction from the Fermilab Tevatron collider obtained by the CDF experiment are reviewed and compared. We report on the diffractive structure function obtained from dijet production in the range $0diffractive events up to $Q^2\\approx 4,500$ GeV$^2$. Results on single diffractive W/Z production, forward jets, and central exclusive production of both dijets and diphotons are also presented.

Michele Gallinaro

2009-04-14

26

Thermal experimental results on the prototype for high power neutron converter for low energy proton/deuteron beams  

NASA Astrophysics Data System (ADS)

In the framework of the European program aimed at the developing of a second generation radioactive ion beam (RIB) facility, the Legnaro National Laboratories (LNL) propose in the next few years the construction of a specialized national facility for RIB originated by fission fragments produced by fast neutrons (SPES). Protons/deuterons of 40 MeV (150 kW) will produce about 10 14 neutrons per second in a converter with energy centered at around 14 MeV which will induce fission in a suitable fissile target, with the aim of 10 13 fissions per second at least. A rotating target includes the converter made of 13C-based material or natural carbon (for proton and deuteron beams, respectively), and cooled mainly by thermal radiation. This paper presents the design of the prototype, as well as the thermal experimental results with high-power electron beams. The prototype comprises the carbon-made neutron converter mounted on the rotating metal disk of 30 cm in diameter and designed to dissipate 50 kW of beam power at nominal operation condition. The test consists of the prototype converter irradiation with the high-power electron beam (beam size below 1 cm) of the ELV-6 accelerator. The prototype successfully remained under nominal conditions. In addition, the prototype was submitted to a beam power of 70 kW, which exceeds of 40% the design power, without any appreciable damage on the converter material. The results are in good agreement with the numerical simulations.

Alyakrinskiy, O.; Antoshin, A.; Avilov, M.; Bolkhovityanov, D.; Fadeev, S.; Golikov, V.; Gubin, K.; Lebedev, N.; Logatchev, P.; Popov, V.; Shiyankov, S.; Tecchio, L. B.

2007-08-01

27

Thermal Energy Measurement with Tangential Paddlewheel Flow Meters: Summary of Experimental Results and in-situ Diagnostics  

E-print Network

a totalized signal for input into a data acquisition system. In this paper a summary of experimental results from calibration efforts in the Texas LoanSTAR program are presented, including the premature drop-out of magnetic-type tangential.... These metering legt can be very costly, ranging from $1,000 to $10,000 in very large pipes. broken with the passing of the rotor blades between the transmitter and receiver which generates an inverted pulse of constant amplitude. The premature10, low-flow drop...

Haberl, J. S.; Watt, J. B.

1994-01-01

28

A New Determination of the Binding Energy of Atomic Oxygen On Dust Grain Surfaces: Experimental Results and Simulations  

NASA Astrophysics Data System (ADS)

The energy to desorb atomic oxygen from an interstellar dust grain surface, Edes, is an important controlling parameter in gas-grain models; its value impacts the temperature range over which oxygen resides on a dust grain. However, no prior measurement has been done of the desorption energy. We report the first direct measurement of Edes for atomic oxygen from dust grain analogs. The values of Edes are 1660 ± 60 and 1850 ± 90 K for porous amorphous water ice and for a bare amorphous silicate film, respectively, or about twice the value previously adopted in simulations of the chemical evolution of a cloud. We use the new values to study oxygen chemistry as a function of depth in a molecular cloud. For n = 104 cm-3 and G0 = 102 (G0 = 1 is the average local interstellar radiation field), the main result of the adoption of the higher oxygen binding energy is that H2O can form on grains at lower visual extinction AV, closer to the cloud surface. A higher binding energy of O results in more formation of OH and H2O on grains, which are subsequently desorbed by far-ultraviolet radiation, with consequences for gas-phase chemistry. For higher values of n and G0, the higher binding energy can lead to a large increase in the column of H2O but a decrease in the column of O2.

He, Jiao; Shi, Jianming; Hopkins, Tyler; Vidali, Gianfranco; Kaufman, Michael J.

2015-03-01

29

Experimental study and computer simulations of the energy loss straggling of slow ions in thin foils: Results for H+ and D+ in C, Si, Cu, Ag and Bi  

NASA Astrophysics Data System (ADS)

We present an experimental and computer simulation study of the energy loss straggling of low energy (2-10 keV) proton and deuteron beams in C, Si, Cu, Ag and Bi. The measurements were done using the transmission technique with several self-supporting foils with thicknesses in the range of 13-25 nm. The computer simulations were based on a Monte Carlo code which provides a method to analyze in detail the influence of various effects, such as foil roughness and slowing down of the ions in the medium. The theoretical model for the stopping and straggling coefficients is based on the Density Functional Theory. The results of the simulations yield a good agreement with the experimental values for the total straggling, taking into account the target roughness which significantly increases the measured energy widths. Within the experimental uncertainties the results show a linear dependence of the energy loss straggling with the projectile velocity and no isotopic effects. The results clearly indicate that a quantitative analysis of the energy loss straggling in this energy range requires a careful evaluation of the foil roughness effect.

Celedón, C. E.; Cantero, E. D.; Lantschner, G. H.; Arista, N. R.

2013-11-01

30

Majorana Thermosyphon Prototype Experimental Results  

SciTech Connect

Objective The Majorana demonstrator will operate at liquid Nitrogen temperatures to ensure optimal spectrometric performance of its High Purity Germanium (HPGe) detector modules. In order to transfer the heat load of the detector module, the Majorana demonstrator requires a cooling system that will maintain a stable liquid nitrogen temperature. This cooling system is required to transport the heat from the detector chamber outside the shield. One approach is to use the two phase liquid-gas equilibrium to ensure constant temperature. This cooling technique is used in a thermosyphon. The thermosyphon can be designed so the vaporization/condensing process transfers heat through the shield while maintaining a stable operating temperature. A prototype of such system has been built at PNNL. This document presents the experimental results of the prototype and evaluates the heat transfer performance of the system. The cool down time, temperature gradient in the thermosyphon, and heat transfer analysis are studied in this document with different heat load applied to the prototype.

Fast, James E.; Reid, Douglas J.; Aguayo Navarrete, Estanislao

2010-12-17

31

TMX-U experimental results  

SciTech Connect

This paper describes results from the Tandem Mirror Experiment-Upgrade (TMX-U). Mirror-confined electrons with 30 to 70 keV mean energy densities of 0.5 to 2.0 x 10/sup 12/ cm/sup -3/ and average betas of 3 to 5% are produced using electron-cyclotron resonant heating (ECRH). These results are consistent with an electron Fokker-Planck code. Improved ion-cyclotron microstability is observed using neutral beam injection at 47/sup 0/ to the magnetic axis, rather than at 90/sup 0/ as in the previous experiment, TMX. Strong end plugging has been produced using a combination of ECRH gyrotrons with sloshing-ion beam injection. In these low-density central cell experiments (3 x 10/sup 11/ cm/sup -3/) the axial losses (tau/sub parallel/ = 20 to 80 ms) are smaller than the nonambipolar radial losses (tau/sub perpendicular/ = 4 to 8 ms). Plugging has been achieved with a central cell density double that of the end plugs. Although no direct measurements are yet available to determine if a thermal barrier potential dip is generated, these experiments support many theoretical features of the thermal barrier concept.

Simonen, T.C.; Allen, S.L.; Casper, T.A.; Clauser, J.F.; Clower, C.A.; Coensgen, F.H.; Correll, D.L.; Cummins, W.F.; Damm, C.C.; Failor, B.H.

1983-08-31

32

A New Determination of the Binding Energy of Atomic Oxygen on Dust Grain Surfaces: Experimental Results and Simulations  

E-print Network

The energy to desorb atomic oxygen from an interstellar dust grain surface, $E_{\\rm des}$, is an important controlling parameter in gas-grain models; its value impacts the temperature range over which oxygen resides on a dust grain. However, no prior measurement has been done of the desorption energy. We report the first direct measurement of $E_{\\rm des}$ for atomic oxygen from dust grain analogs. The values of $E_{\\rm des}$ are $1660\\pm 60$~K and $1850\\pm 90$~K for porous amorphous water ice and for a bare amorphous silicate film, respectively, or about twice the value previously adopted in simulations of the chemical evolution of a cloud. We use the new values to study oxygen chemistry as a function of depth in a molecular cloud. For $n=10^4$ cm$^{-3}$ and $G_0$=10$^2$ ($G_0$=1 is the average local interstellar radiation field), the main result of the adoption of the higher oxygen binding energy is that H$_2$O can form on grains at lower visual extinction $A_{\\rm V}$, closer to the cloud surface. A higher ...

He, Jiao; Hopkins, Tyler; Vidali, Gianfranco; Kaufman, Michael J

2015-01-01

33

Experimental results on heavy quark fragmentation  

E-print Network

Experimental results on c- and b-quark fragmentation are reviewed. The discussion is concentrated on measurements of heavy-quark fragmentation functions and fragmentation fractions. Measurements of various heavy-quark fragmentation ratios are also discussed. The experimental results are compared with theoretical expectations and model predictions.

Leonid Gladilin

2006-07-20

34

An Overview of STAR Experimental Results  

E-print Network

With large acceptance and excellent particle identification, STAR is one of the best mid-rapidity collider experiments for studying high-energy nuclear collisions. The STAR experiment provides full information on initial conditions, properties of the hot and dense medium as well as the properties at freeze-out. In Au+Au collisions at $\\sqrt{s_{NN}} = 200$ GeV, STAR's focus is on the nature of the sQGP produced at RHIC. In order to explore the properties of the QCD phase diagram, since 2010, the experiment has collected sizable data sets of Au+Au collisions at the lower collision energy region where the net-baryon density is large. At the 2014 Quark Matter Conference, the STAR experiment made 16 presentations that cover physics topics including {\\it collective dynamics}, {\\it electromagnetic probes}, {\\it heavy flavor}, {\\it initial state physics}, {\\it jets}, {\\it QCD phase diagram}, {\\it thermodynamics and hadron chemistry}, and {\\it future experimental facilities, upgrades, and instrumentation} [1-16]. In this overview we will highlight a few results from the STAR experiment, especially those from the recent measurements of the RHIC beam energy scan program. At the end, instead of a summary, we will discuss STAR's near future physics programs at RHIC.

N. Xu

2014-08-15

35

An overview of STAR experimental results  

NASA Astrophysics Data System (ADS)

With large acceptance and excellent particle identification, STAR is one of the best mid-rapidity collider experiments for studying high-energy nuclear collisions. The STAR experiment provides full information on initial conditions, properties of the hot and dense medium as well as the properties at freeze-out. In Au+Au collisions at ?{sNN} = 200 GeV, STAR's focus is on the nature of the sQGP produced at RHIC. In order to explore the properties of the QCD phase diagram, since 2010, the experiment has collected sizable data sets of Au+Au collisions at the lower collision energy region where the net-baryon density is large. At the 2014 Quark Matter Conference, the STAR experiment made 16 presentations that cover physics topics including collective dynamics, electromagnetic probes, heavy-flavor, initial state physics, jets, QCD phase diagram, thermodynamics and hadron chemistry, and future experimental facilities, upgrades, and instrumentation[1]. In this overview we will highlight a few results from the STAR experiment, especially those from the recent measurements of the RHIC beam energy scan program. At the end, instead of a summary, we will discuss STAR's near future physics programs at RHIC.

Xu, Nu

2014-11-01

36

Synthesis of H2 in dirty ice mantles by fast ion energy loss: New experimental results increase the relevance of this mechanism  

NASA Technical Reports Server (NTRS)

Recent experimental results support the importance of H2 production in molecular clouds by cosmic ray bombardment of the mantles of grains. The formation of molecules different from those originally present in the irradiated layer can be explained by the production of molecular fragments induced by the release of energy if the impinging fast particle. One way of considering the process is in terms of a transiently hot cylinder, initially about 50 A in diameter, that exists around the track of an individual fast ion. Since ice has a relatively low thermal conductivity, energy lost by the ion in the ice layers remains confined around the track for time long enough to be thermalized. The hot cylinder increases in diameter and decreases in temperature on a time scale of 10(exp -11) to 10(exp -10) sec. Molecular fragments that are formed in this high temperature region acquire enough mobility to recombine with different partners, forming new molecules. A Monte Carlo simulation of the interaction between cosmic rays and grain mantles, at various depths in the core of a spherical molecular cloud, was performed. The simulation was continued until 40,000 ions had hit each grain of the type and size chosen. During the performed experiments thin icy films made of H2O and CD4 mixed in the gas phase and deposited on a cold finger at 9 K were irradiated with 1.5 MeV helium beams. Among synthesized molecules were found H2, HD, and D2.

Pirranello, Valero; Brown, W. L.; Lanzerotti, L. J.; Averna, D. A.

1989-01-01

37

Review of SIS Experimental Results on Strangeness  

E-print Network

>A review of meson emission in heavy ion collisions at incident energies around 1 -- 2 $A\\cdot$GeV is presented. It is shown how the shape of the spectra and the various particle yields vary with system size, with centrality and with incident energy. A statistical model assuming thermal and chemical equilibrium and exact strangeness conservation (i.e. strangeness conservation per collision) explains most of the observed features. Emphasis is put onto the study of $K^+$ and $K^-$ emission. In the framework of this statistical model it is shown that the experimentally observed equality of $K^+$ and $K^-$ rates at threshold corrected energies $\\sqrt{s} - \\sqrt{s_{th}}$ is due to a crossing of two excitation functions. Furthermore, the independence of the $K^+$ to $K^-$ ratio on the number of participating nucleons observed between 1 and 10 $A\\cdot$GeV is consistent with this model. The observed flow effects are beyond the scope of this model.

Helmut Oeschler

2000-11-09

38

PDX experimental results in FY82  

SciTech Connect

This report presents a detailed summary of the major experimental results of PDX in FY82 and represents the efforts of the entire PDX group. Topics covered include ..beta..-scaling and fishbone studies, fluctuations, disruptions, impurities and impurity transport, power handling, limiter conditioning, edge studies, plasma fueling, counter-injection, and diagnostic development. A less detailed version will appear as the FY82 PDX contribution to the PPPL Annual Report.

Kaye, S.M.; Bell, M.; Bol, K.; Bitter, M.; Buchenauer, D.; Budny, R.; Brau, K.; Crowley, T.; Davis, S.; Dylla, H.

1983-08-01

39

Comparison between theoretical and experimental results for energy states of two-dimensional electron gas in pseudomorphically strained InAs high-electron-mobility transistors  

NASA Astrophysics Data System (ADS)

The energy states of a two-dimensional electron gas (2DEG) in high-electron-mobility transistors with a pseudomorphically strained InAs channel (PHEMTs) were analyzed rigorously using a recently established theory that takes into account the nonparabolicity of the conduction band of the channel layer. The sheet density of the 2DEG in InxGa1-xAs-PHEMTs and the drain I-V characteristics of those devices were calculated theoretically and compared with the density and characteristics obtained experimentally. Not only the calculated threshold voltage (VTH) but also the calculated transconductance agreed fairly well with the corresponding values obtained experimentally. When the effects of the compositions of the InxGa1-xAs subchannel layer in the composite channel and the channel layer on energy states of 2DEG were investigated in order to establish a guiding principle for a design of the channel structure in PHEMTs, it was found that VTH is determined by the effective conduction-band offset energy ?EC between the InAlAs barrier and the channel layers.

Nishio, Yui; Tange, Takahiro; Hirayama, Naomi; Iida, Tsutomu; Takanashi, Yoshifumi

2014-01-01

40

Overview of the Initial NSTX Experimental Results  

SciTech Connect

The main aim of the National Spherical Torus Experiment (NSTX) is to establish the fusion physics principles of the spherical torus (ST) concept. The NSTX device began plasma operations in February 1999 and the plasma current Ip was successfully brought up to the design value of 1 million amperes on December 14, 1999. The planned plasma shaping parameters, k = 1.6 {+-} 2.2 and d = 0.2 {+-} 0.4, were achieved in inner limited, single null and double null configurations. The CHI (Coaxial Helicity Injection) and HHFW (High Harmonic Fast Wave) experiments were also initiated. A CHI injected current of 27 kA produced up to 260 kA of toroidal current without using an ohmic solenoid. With an injection of 2.3 MW of HHFW power, using twelve antennas connected to six transmitters, electrons were heated from a central temperature of 400 eV to 900 eV at a centraldensity of 3.5 x 1013 cm-3 increasing the plasma energy to 59 kJ and the toroidal beta, bT to 10 %. Finally, the NBI system commenced operatio n in Sept. 2000. The initial results with two ion sources (PNBI = 2.8 MW) shows good heating, producing a total plasma stored energy of 90 kJ corresponding to bT = 18 % at a plasma current of 1.1 MA

M. Ono; M. Bell; R. E. Bell; T. Bigelow; M. Bitter; et al

2000-11-16

41

Overview of the Initial NSTX Experimental Results  

SciTech Connect

The main aim of the National Spherical Torus Experiment (NSTX) is to establish the fusion physics principles of the spherical torus (ST) concept. The NSTX device began plasma operations in February 1999 and the plasma current Ip was successfully brought up to the design value of 1 million amperes on December 14, 1999. The planned plasma shaping parameters, k = 1.6 - 2.2 and d = 0.2 - 0.4, were achieved in inner limited, single null and double null configurations. The CHI (Coaxial Helicity Injection) and HHFW (High Harmonic Fast Wave) experiments were also initiated. A CHI injected current of 27 kA produced up to 260 kA of toroidal current without using an ohmic solenoid. With an injection of 2.3 MW of HHFW power, using twelve antennas connected to six transmitters, electrons were heated from a central temperature of 400 eV to 900 eV at a central density of 3.5 x 1013 cm-3 increasing the plasma energy to 59 kJ and the toroidal beta, bT to 10 %. Finally, the NBI system commenced operation in Sept. 2000. The initial results with two ion sources (PNBI = 2.8 MW) shows good heating, producing a total plasma stored energy of 90 kJ corresponding to bT 18 % at a plasm current of 1.1 MA.

Ono, M. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Bell, M. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Bigelow, Tim S [ORNL] [ORNL; Bitter, M. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Blanchard, W. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Darrow, D. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Fredrickson, E. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Gates, D. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Grisham, L. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Hosea, J. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Kaye, S. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Kaita, R. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Kubota, S. [University of California, Los Angeles] [University of California, Los Angeles; Kugel, H. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Johnson, D. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Maingi, Rajesh [ORNL] [ORNL; Maqueda, R. [Los Alamos National Laboratory (LANL)] [Los Alamos National Laboratory (LANL); Mazzucato, E. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Menard, J. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Mueller, D. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Nelson, Brad E [ORNL] [ORNL; Neumeyer, C. L. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Paoletti, F. [Columbia University] [Columbia University; Paul, S. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Peng, Yueng Kay Martin [ORNL] [ORNL; Ramakrishnan, S. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Raman, R. [University of Washington, Seattle] [University of Washington, Seattle; Ryan, Philip Michael [ORNL] [ORNL; Sabbagh, S. A. [Columbia University] [Columbia University; Skinner, C. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Stevenson, T. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Stutman, D. [Johns Hopkins University] [Johns Hopkins University; Synakowski, E. J. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Swain, David W [ORNL] [ORNL; Taylor, G. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Von Halle, A. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Wilgen, John B [ORNL] [ORNL; Williams, M. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Wilson, J. R. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Ackers, R. [EURATOM / UKAEA, UK] [EURATOM / UKAEA, UK; Barry, Robert E [ORNL] [ORNL; Bers, A. [Massachusetts Institute of Technology (MIT)] [Massachusetts Institute of Technology (MIT); Bialek, J. [Columbia University] [Columbia University; Bonoli, P. [Massachusetts Institute of Technology (MIT)] [Massachusetts Institute of Technology (MIT); Carter, Mark Dwain [ORNL] [ORNL; Chrzanowski, J. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Davis, W. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL)

2001-01-01

42

Initial Experimental Results on a Pulse Line Ion Accelerator  

NASA Astrophysics Data System (ADS)

A new method of accelerating intense ion bunches has been investigated. The Pulse Line Ion Accelerator (PLIA) is best suited as an accelerator for intense bunches with pulse lengths of tens of cm. In a first beam dynamics validation experiment for the new PLIA concept, the predicted energy amplification and beam bunching were experimentally observed. Beam energy modulation of -80 keV to +150 keV was measured using a PLIA input voltage waveform of -21 kV to +12 kV. Ion pulses accelerated by 150 keV, and bunching by a factor of four were simultaneously achieved. The measured longitudinal phase space and current waveform of the accelerated beam are in good agreement with 3-D particle-in-cell simulations. Here we present initial experimental results of the PLIA as a proof-of-principle (POP) of the concept.

Roy, Prabir K.; Waldron, William L.; Yu, Simon S.; Coleman, Joshua E.; Henestroza, Enrique; Bieniosek, Frank M.; Leitner, Matthaeus; Seidl, Peter A.; Baca, David; Greenway, Wayne G.; Eylon, Shmuel; Reginato, Louis L.; Logan, Grant B.; Grote, David P.; Friedman, Alex; Briggs, Richard J.; Davidson, Ronald C.

2006-10-01

43

Experimental Results on Rotor Wakes Narayanan Komerath  

E-print Network

Engineering Georgia Institute of Technology, Atlanta The wake of a rotor is at once an extremely complex these advances, shown both experimentally and through analysis and computation, it has become possible. Meanwhile, the ancient disconnect between the correct wake geometry as calculated from blade loading

44

Experimental Test Results of the Energy Efficient Transport (EET) Flap-Edge Vortex Model in the Langley Low-Turbulence Pressure Tunnel  

NASA Technical Reports Server (NTRS)

This report presents the results of a test conducted in the Langley Low-Turbulence Pressure Tunnel to measure the flow field properties of a flap-edge vortex. The model was the EET (Energy Efficient Transport) Flap-Edge Vortex Model, which consists of a main element and a part-span, single-slotted trailing-edge flap. The model surface was instrumented with several chordwise and spanwise rows of pressure taps on each element. The off-body flow field velocities were to be measured in several planes perpendicular to the flap edge with a laser velocimetry system capable of measuring all three components in coincidence. However, due to seeding difficulties, the preliminary laser data did not have sufficient accuracy to be suitable for presentation; therefore, this report presents only the tabulated and plotted surface pressure data. In addition, the report contains a detail description of the model which can be used to generate accurate CFD grid structures.

Morgan, Harry L., Jr.

2002-01-01

45

Experimental High Energy Neutrino Astrophysics  

SciTech Connect

Neutrinos are considered promising probes for high energy astrophysics. More than four decades after deep water Cerenkov technique was proposed to detect high energy neutrinos. Two detectors of this type are successfully taking data: BAIKAL and AMANDA. They have demonstrated the feasibility of the high energy neutrino detection and have set first constraints on TeV neutrino production astrophysical models. The quest for the construction of km3 size detectors have already started: in the South Pole, the IceCube neutrino telescope is under construction; the ANTARES, NEMO and NESTOR Collaborations are working towards the installation of a neutrino telescope in the Mediterranean Sea.

Distefano, Carla [Laboratori Nazionali del Sud, Catania (Italy)

2005-10-12

46

Experimental results of an autonomous underwater vehicle \\  

Microsoft Academic Search

Japan Marine Science and Technology Center (JAMSTEC) has advanced the development of an ocean going autonomous underwater vehicle (AUV). Technical problem on an AUV is to develop instruments for digital telemetry, highly accurate positioning in the sea and an efficient power source. The AUV in JAMSTEC has digital telemetry, accurate positioning system and high energy density battery. Sea test started

S. Tsukioka; T. Aoki; T. Murashima; H. Yoshida; H. Nakajoh; T. Hyakudome; S. Ishibashi; K. Hirokawa

2003-01-01

47

Experimental results on quantum chromo dynamics: what is next?  

NASA Astrophysics Data System (ADS)

This review gives a flavour of experimental quantum chromo dynamics (QCD) results obtained at the Large Hadron Collider (LHC) during the first run period in the years 2010-2012. The results cover selected aspects of soft low-pT phenomena, typically described by phenomenological models, as well as high-pT processes which can be studied theoretically with perturbative techniques. In general the phenomenological models required tuning to describe the data in the new energy region of 7-8 TeV, while perturbative QCD (pQCD) is found to work generally quite well for most of the phase space currently studied. The strong force will remain a main topic of research at colliders such as the LHC also in future, with the large data samples allowing for more detailed studies and in particular when the next energy level of 13-14 TeV will be reached.

De Roeck, Albert

2013-12-01

48

CROSSBREEDING FOR BEEF PRODUCTION: EXPERIMENTAL RESULTS 1  

Microsoft Academic Search

Summary One approach to summarizing the research results from cattle crossbreeding studies is to consider the relative importance of breed differences, reciprocal differences and heterosis as they affect various characters. Breed effects as indicated by the maximum differences outlined in this review were of moderate to high magnitude for most of the characters considered. This result implies that selection among

Charles R. Long

2009-01-01

49

On collisional disruption - Experimental results and scaling laws  

NASA Technical Reports Server (NTRS)

Both homogeneous and inhomogeneous targets have been addressed by the present experimental consideration of the impact strengths, fragment sizes, and fragment velocities generated by cement mortar targets whose crushing strengths vary by an order of magnitude, upon impact of projectiles in the velocity range of 50-5700 m/sec. When combined with additional published data, dynamic impact strength is found to correlate with quasi-static material strengths for materials ranging in character from basalt to ice; two materials not following this trend, however, are weak mortar and clay targets. Values consistent with experimental results are obtainable with a simple scaling algorithm based on impact energy, material properties, and collisional strain rate.

Davis, Donald R.; Ryan, Eileen V.

1990-01-01

50

Experimental rotordynamic coefficient results for honeycomb seals  

NASA Technical Reports Server (NTRS)

Test results (leakage and rotordynamic coefficients) are presented for seven honeycomb-stator smooth-rotor seals. Tests were carried out with air at rotor speeds up to 16,000 cpm and supply pressures up to 8.2 bars. Test results for the seven seals are compared, and the most stable configuration is identified based on the whirl frequency ratio. Results from tests of a smooth-rotor/smooth-stator seal, a teeth-on-stator labyrinth seal, and the most stable honeycomb seal are compared.

Elrod, David A.; Childs, Dara W.

1988-01-01

51

Autograft meniscus replacement: Experimental and clinical results  

Microsoft Academic Search

Because of the risks related to allograft meniscus replacement an attempt was made to replace the medial meniscus by autograft tissue. In animal experiments the free middle third of the patellar tendon was transformed to a meniscus-like structure within one year after insertion. Early arthroscopic results after autograft meniscus replacement in a clinical series comprising 20 patients are promising.

D. Kohn

1993-01-01

52

Numerical taxonomy on data: Experimental results  

SciTech Connect

The numerical taxonomy problems associated with most of the optimization criteria described above are NP - hard [3, 5, 1, 4]. In, the first positive result for numerical taxonomy was presented. They showed that if e is the distance to the closest tree metric under the L{sub {infinity}} norm. i.e., e = min{sub T} [L{sub {infinity}} (T-D)], then it is possible to construct a tree T such that L{sub {infinity}} (T-D) {le} 3e, that is, they gave a 3-approximation algorithm for this problem. We will refer to this algorithm as the Single Pivot (SP) heuristic.

Cohen, J.; Farach, M. [Rutgers Univ., Piscataway, NJ (United States)

1997-12-01

53

Experimental results of bispectral invariants discriminative power  

NASA Astrophysics Data System (ADS)

One of the main tools in shape matching and pattern recognition are invariants. For three-dimensional data, rotation invariants comprise of two main kinds: moments and spherical harmonic magnitudes. Both are well examined and both suffer from certain limitations. In search for better performance, a new kind of spherical-harmonic invariants have been proposed recently, called bispectral invariants. They are well-established from theoretical point of view. They posses numerous beneficial properties and advantages over other invariants, include the ability to distinguish rotation from reflection, and the sensitivity to phase. However, insufficient research has been conducted to check their behavior in practice. In this paper, results are presented pertaining to the discriminative power of bispectral invariants. Objects from Princeton Shape Benchmark database are used for evaluation. It is shown that the bispectral invariants outperform power spectral invariants, but perform worse than other descriptors proposed in the literature such as SHELLS and SHD. The difference in performance is attributable to the implicit filtering used to compute the invariants.

Kubicki, Karol; Kakarala, Ramakrishna

2012-03-01

54

Theoretical and Experimental Results Regarding LENR/CF  

SciTech Connect

We challenge the predominant view that low-energy nuclear reactions (LENRs) are prohibited by standard quantum mechanics (QM). This view, supposedly based on standard nuclear theory, need not apply in condensed-matter environments. These considerations indicate that seemingly novel experimental evidence of rapid aneutronic bulk-process transmutation, at extraordinarily low-energy levels, in a simple electrochemical reactor, can occur. This explains: (a) induced rapid decay of radioactive thorium into stable nuclides, e.g., Cu and (b) resulting, anomalous distribution of Cu isotopes. We reexamine arguments of Peebles cited as evidence that standard QM 'forbids' cold fusion (CF). We note oversimplifications in those and present an alternative, more sophisticated calculation (see Bass, Refs. 3 through 8) demonstrating that conventional wisdom about impenetrability of the 'Coulomb barrier' fails as a result of periodic-order-induced resonance. We also examine empirical evidence. In three independent tests of an LENR electrolysis cell, using different I-V-T (current/voltage/time) protocols, the percentage of radiation reduction (RR) transmutation achieved {eta}=[23{percent}, 50{percent}, 83{percent}] versus expended energy E=[0.6535, 32.5, 74.6] (Watt-hours), obtained by numerical integration of recorded product I{center_dot}V for processing time T, provides near-perfect straight-line correlation: {eta}={alpha}{center_dot}E + {eta}{sub 0}, {alpha}=0.8105, {eta}{sub 0}=22.888, (0.65 < E < 0.75).

Robert W. Bass; Wm. Stan Gleeson

2000-11-12

55

Initial Experimental Results on a Pulse Line Ion Accelerator  

Microsoft Academic Search

A new method of accelerating intense ion bunches has been investigated. The Pulse Line Ion Accelerator (PLIA) is best suited as an accelerator for intense bunches with pulse lengths of tens of cm. In a first beam dynamics validation experiment for the new PLIA concept, the predicted energy amplification and beam bunching were experimentally observed. Beam energy modulation of -80

Prabir K. Roy; William L. Waldron; Simon S. Yu; Joshua E. Coleman; Enrique Henestroza; Frank M. Bieniosek; Matthaeus Leitner; Peter A. Seidl; David Baca; Wayne G. Greenway; Shmuel Eylon; Louis L. Reginato; Grant B. Logan; David P. Grote; Alex Friedman; Richard J. Briggs; Ronald C. Davidson

2006-01-01

56

Methods of experimentation with models and utilization of results  

NASA Technical Reports Server (NTRS)

The present report treats the subject of testing small models in a wind tunnel and of the methods employed for rendering the results constant, accurate and comparable with one another. Detailed experimental results are given.

Robert,

1924-01-01

57

Experimental Results of Hydrate Reservoir Destabilization Through Heating  

NASA Astrophysics Data System (ADS)

Gas clathrate reservoirs have been considered as possible sources of energy, as hazards to deep water drilling operations, and as contributors to global climate change. Clathrate destabilization may occur through depressurization of the reservoir, addition of chemical inhibitors, or heating the reservoir. Meso-scale heat conduction experiments were conducted in the Seafloor Process Simulator (SPS) at Oak Ridge National Laboratory in an attempt to apply experimental constraints to purely numerical models of heat transfer within a nearly isobaric reservoir. A column of saturated sediment was place inside the pressure vessel and pressurized to conditions sufficient to form methane clathrate at seafloor temperatures, while the system remained at room temperature (298K). Once pressurized, the temperature of the vessel was then lowered to approximately 275K, forming pore filling clathrate in the sediment column. Following hydrate formation, heat was supplied to the center of the clathrate reservoir through a hot fluid heat exchanger embedded in the sediment column to dissociate the methane hydrate. Relative changes in temperature within the hydrate-sediment column were monitored with a fiber optic quasi-distributed sensing system (DSS), along with temperature and pressure within the vessel headspace. Using the DSS Plotter analysis software, it was determined that an axis-symmetric section of clathrate was dissociated around the heat exchanger. Clathrate dissociation was accompanied by a small rise in vessel headspace pressure in addition to the expected thermal expansion of the headspace gas. The quantity of heat input to the system was calculated from the drop in fluid temperature as it flowed through the heat exchanger. Increased heat input resulted in an increase in the volume of hydrate dissociated. Clathrate rapidly reformed immediately upon the removal of the heat energy. A simple numerical model has been developed to simulate the heat flow in the system. Early results are promising and with further refinement the gap between the volume of hydrate dissociation predicted from the model and the experimental data observed on the LUNA DSS system will close. Much of the thermal energy is used to counter the heat of dissociation and heat input from the cold room the vessel is in. Some thermal energy was also lost in the pipelines inside the vessel.

Leeman, J.; Hornbach, M. J.; Elwood-Madden, M.; Phelps, T. J.; Rawn, C. J.

2011-12-01

58

Neutrinos from the Sun: experimental results confronted with solar models  

E-print Network

For standard neutrinos, recent solar neutrino results together with the assumption of a nuclearly powered Sun imply severe constraints on the individual components of the total neutrino flux: \\Phi_{Be}<0.7*10^9cm^-2 s^-1, \\Phi_{CNO}< 0.6*10^9 cm^-2 s^-1, and $64*10^9 cm^-2 s^-1< \\Phi_{pp+pep} < 65*10^9 cm^-2 s^-1 (at 1 \\sigma level). The bound on \\Phi_{Be} is in strong disagreement with the standard solar model prediction \\Phi_{Be}^{SSM}\\approx 5*10^9 cm^-2 s^-1. We study a large variety of non-standard solar models with low inner temperature, finding that the temperature profiles T(m) follow the homology relationship: T(m)=kT^{SSM}(m), so that they are specified just by the central temperature T_c. There is no value of T_c which can account for all the available experimental results. Even if we only consider the Gallium and Kamiokande results, they remain incompatible. Lowering the cross section p+Be7 \\to \\gamma+B8 is not a remedy. The shift of the nuclear fusion chain towards the pp-I termination could be induced by a hypothetical low energy resonance in the He3+He3 reaction. This mechanism gives a somehow better, but still bad fit to the combined experimental data. We also discuss what can be learnt from new generation experiments about the properties of neutrinos and of the Sun.

Vittorio Castellani; Scilla Degl'innocenti; Gianni Fiorentini; Marcello Lissia; Barbara Ricci

1994-05-27

59

Acoustic analysis in Mudejar-Gothic churches: experimental results.  

PubMed

This paper describes the preliminary results of research work in acoustics, conducted in a set of 12 Mudejar-Gothic churches in the city of Seville in the south of Spain. Despite common architectural style, the churches feature individual characteristics and have volumes ranging from 3947 to 10 708 m3. Acoustic parameters were measured in unoccupied churches according to the ISO-3382 standard. An extensive experimental study was carried out using impulse response analysis through a maximum length sequence measurement system in each church. It covered aspects such as reverberation (reverberation times, early decay times), distribution of sound levels (sound strength); early to late sound energy parameters derived from the impulse responses (center time, clarity for speech, clarity, definition, lateral energy fraction), and speech intelligibility (rapid speech transmission index), which all take both spectral and spatial distribution into account. Background noise was also measured to obtain the NR indices. The study describes the acoustic field inside each temple and establishes a discussion for each one of the acoustic descriptors mentioned by using the theoretical models available and the principles of architectural acoustics. Analysis of the quality of the spaces for music and speech is carried out according to the most widespread criteria for auditoria. PMID:15957758

Galindo, Miguel; Zamarreño, Teófilo; Girón, Sara

2005-05-01

60

Theoretical and Experimental Results Regarding LENR\\/CF  

Microsoft Academic Search

We challenge the predominant view that low-energy nuclear reactions (LENRs) are prohibited by standard quantum mechanics (QM). This view, supposedly based on standard nuclear theory, need not apply in condensed-matter environments. These considerations indicate that seemingly novel experimental evidence of rapid aneutronic bulk-process transmutation, at extraordinarily low-energy levels, in a simple electrochemical reactor, can occur. This explains: (a) induced rapid

Robert W. Bass; Wm. Stan Gleeson

2000-01-01

61

Experimental energy straggling of protons in SiO2  

NASA Astrophysics Data System (ADS)

The energy straggling of proton beams in SiO2 has been measured in the energy range from 30 to 1500 keV using the transmission, nuclear reaction analysis and Rutherford backscattering techniques. The experimental results are compared with theoretical models. We observe that at energies around 200 keV the values obtained are larger than theoretical estimations. The straggling effect produced by the electron bunching in molecular media was calculated and it was found to be a possible cause of these differences at intermediate energies.

Dos Santos, J. H.; Grande, P. L.; Behar, M.; Dias, J. F.; Arista, N. R.; Eckardt, J. C.; Lantschner, G. H.

2003-10-01

62

Ground coupled heat-pump-system experimental results  

NASA Astrophysics Data System (ADS)

Since October 1980, a small house in Upton, Long Island, New York has been heated and cooled by a liquid source heat pump using a shallow serpentine earth coil as a heat source/sink. After a brief introduction and system description, system performance data are presented, for the winter of 1981-82 and the summer of 1982, followed by a discussion of these results. The experimental test house is a 104 m(2) (1120 ft(2)) 3 bedroom ranch of energy saving construction with a heating load of 7.8 x 10 to the 6th power J/0C-day (4.1 x 10 to the 3rd power Btu/0F-day). The heat pump used during most of the period reported on here is a commercially available water to air unit sized to just meet the building design heating load with no auxiliary heat. The earth coil contains 155 m (507 ft) of nominal 1-1/2 in. medium density polyethylene pipe, and is approximately 25% ethylene glycol in water, is employed to permit subfreezing earth coil operation. Two independent data acquisition systems, a datalogger microcomputer system backed up by a Btu meter, monitor the space conditioning system performance.

Metz, P. D.

1983-06-01

63

Experimental results for Titan aerobot thermo-mechanical subsystem development  

Microsoft Academic Search

This paper describes experimental results from a development program focused on maturing Titan aerobot technology in the areas of mechanical and thermal subsystems. Results from four key activities are described: first, a cryogenic balloon materials development program involving coupon and cylinder tests and culminating in the fabrication and testing of an inflated 4.6m long prototype blimp at 93K; second, a

J. L. Hall; J. A. Jones; V. V. Kerzhanovich; T. Lachenmeier; P. Mahr; M. Pauken; G. A. Plett; L. Smith; M. L. Van Luvender; A. H. Yavrouian

2008-01-01

64

Experimental results for Titan aerobot thermo-mechanical subsystem development  

Microsoft Academic Search

This paper describes experimental results from a development program focused in maturing Titan aerobot technology in the areas of mechanical and thermal subsystems Results from four key activities are described first a cryogenic balloon materials development program involving coupon and cylinder tests and culminating in the fabrication and subsequent testing of an inflated 4 6 m long prototype blimp at

J. Hall; J. Jones; V. Kerzhanovich; T. Lachenmeier; P. Mahr; M. Pauken; G. Plett; L. Smith; M. van Luvender; A. Yavrouian

2006-01-01

65

Experimental and theoretical high energy physics program  

NASA Astrophysics Data System (ADS)

Experimental and theoretical high-energy physics research at Purdue is summarized in a number of reports. Subjects treated include the following: the CLEO experiment for the study of heavy flavor physics; gas microstrip detectors; particle astrophysics; affine Kac-Moody algebra; nonperturbative mass bounds on scalar and fermion systems due to triviality and vacuum stability constraints; resonance neutrino oscillations; e(+)e(-) collisions at CERN; (bar p)-p collisions at FNAL; accelerator physics at Fermilab; development work for the SDC detector at SSC; TOPAZ; D-zero physics; physics beyond the standard model; and the Collider Detector at Fermilab.

Finley, J.; Gaidos, J. A.; Loeffler, F. J.; McIlwain, R. L.; Miller, D. H.; Palfrey, T. R.; Shibata, E. I.; Shipsey, I. P.

1993-04-01

66

[Experimental and theoretical high energy physics program  

SciTech Connect

Experimental and theoretical high-energy physics research at Purdue is summarized in a number of reports. Subjects treated include the following: the CLEO experiment for the study of heavy flavor physics; gas microstrip detectors; particle astrophysics; affine Kac{endash}Moody algebra; nonperturbative mass bounds on scalar and fermion systems due to triviality and vacuum stability constraints; resonance neutrino oscillations; e{sup +}e{sup {minus}} collisions at CERN; {bar p}{endash}p collisions at FNAL; accelerator physics at Fermilab; development work for the SDC detector at SSC; TOPAZ; D-zero physics; physics beyond the standard model; and the Collider Detector at Fermilab. (RWR)

Finley, J.; Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

1993-04-01

67

A review of experimental results at the knee  

E-print Network

Results of experiments investigating air showers in the energy region of the knee are summarized. The all-particle energy spectrum, the mean logarithmic mass, and the average depth of the shower maximum will be discussed. Spectra for groups of elements from air shower data are compared to results from direct measurements.

Joerg R. Hoerandel

2005-07-31

68

Robust control of active magnetic suspension: Analytical and experimental results  

NASA Astrophysics Data System (ADS)

A robust control of an active radial homopolar magnetic bearing system is considered in the paper. The robust control of a rigid rotor vibration is designed analytically and confirmed by experimental investigations. A digital signal processor (DSP) is used to implement the control algorithm and the position control loop is executed in real time. The stability of system with disturbance interaction is discussed. The success of the robust control is demonstrated through results of computer simulations. Finally, experimental results show the effectiveness of the control system as well as good initial responses/transient responses and robustness of the designed controller.

Gosiewski, Zdzis?aw; Mystkowski, Arkadiusz

2008-08-01

69

Game Play in Engineering Education Concept and Experimental Results*  

E-print Network

Game Play in Engineering EducationÐ Concept and Experimental Results* BJARNE A. FOSS Department.foss@itk.ntnu.no TOR I. EIKAAS Cyberlab.Org AS, Trondheim, Norway Dynamic simulators combined with educational games of today's students obtained from extensive use of interactive computer games. This paper presents a design

Foss, Bjarne A.

70

Nonlinear fundamental photothermal response: experimental results for tungsten  

E-print Network

Nonlinear fundamental photothermal response: experimental results for tungsten A. Salnicka,*, J structures containing a tungsten layer is presented. Two sets of wafers, one with a very rough tungsten overlayer surface and another with a smooth polished tungsten surface have been studied. It is shown

Mandelis, Andreas

71

Laser cooling of magnesium ions: Preliminary experimental results  

Microsoft Academic Search

We describe a laser-cooling experiment on Mg+ ions confined in an electromagnetic trap (Penning trap or rf trap) and give the preliminary experimental results. In particular, we have observed a laser cooling in the Penning trap configuration in which a measured temperature of about 1 K has been obtained.

F. Plumelle; M. Desaintfuscien; M. Jardino; P. Petit

1986-01-01

72

Amplified energy harvester from footsteps: design, modeling, and experimental analysis  

NASA Astrophysics Data System (ADS)

This paper presents the design, modeling and experimental analysis of an amplified footstep energy harvester. With the unique design of amplified piezoelectric stack harvester the kinetic energy generated by footsteps can be effectively captured and converted into usable DC power that could potentially be used to power many electric devices, such as smart phones, sensors, monitoring cameras, etc. This doormat-like energy harvester can be used in crowded places such as train stations, malls, concerts, airport escalator/elevator/stairs entrances, or anywhere large group of people walk. The harvested energy provides an alternative renewable green power to replace power requirement from grids, which run on highly polluting and global-warming-inducing fossil fuels. In this paper, two modeling approaches are compared to calculate power output. The first method is derived from the single degree of freedom (SDOF) constitutive equations, and then a correction factor is applied onto the resulting electromechanically coupled equations of motion. The second approach is to derive the coupled equations of motion with Hamilton's principle and the constitutive equations, and then formulate it with the finite element method (FEM). Experimental testing results are presented to validate modeling approaches. Simulation results from both approaches agree very well with experimental results where percentage errors are 2.09% for FEM and 4.31% for SDOF.

Wang, Ya; Chen, Wusi; Guzman, Plinio; Zuo, Lei

2014-04-01

73

Initial experimental results using the noise correlation radar  

NASA Astrophysics Data System (ADS)

Experimental results from recent field testing with the noise correlation radar (NCR) are presented as a proof of concept. In order to understand the effectiveness of the NCR, a predetermined set of measures is established. We discuss the three experimental configurations used in evaluating the system's range resolution/error, robustness to interference, and secure radio frequency (RF) emission. We show that the advanced pulse compression noise (APCN) radar waveform has low range measurement error, is robust to interference, and is spectrally nondeterministic. In addition, we determine that an improvement in range resolution due to phase modulation is achieved as a function of the random code length rather than the compressed pulse length.

Govoni, Mark A.; Silvious, Jerry; Clark, John; Overman, Charles

2013-05-01

74

Design and experimental results for the S805 airfoil  

SciTech Connect

An airfoil for horizontal-axis wind-turbine applications, the S805, has been designed and analyzed theoretically and verified experimentally in the low-turbulence wind tunnel of the Delft University of Technology Low Speed Laboratory, The Netherlands. The two primary objectives of restrained maximum lift, insensitive to roughness, and low profile drag have been achieved. The airfoil also exhibits a docile stall. Comparisons of the theoretical and experimental results show good agreement. Comparisons with other airfoils illustrate the restrained maximum lift coefficient as well as the lower profile-drag coefficients, thus confirming the achievement of the primary objectives.

Somers, D.M. [Airfoils, Inc., State College, PA (United States)

1997-01-01

75

Experimental results for a hypersonic nozzle/afterbody flow field  

NASA Technical Reports Server (NTRS)

This study was conducted to experimentally characterize the flow field created by the interaction of a single-expansion ramp-nozzle (SERN) flow with a hypersonic external stream. Data were obtained from a generic nozzle/afterbody model in the 3.5 Foot Hypersonic Wind Tunnel at the NASA Ames Research Center, in a cooperative experimental program involving Ames and McDonnell Douglas Aerospace. The model design and test planning were performed in close cooperation with members of the Ames computational fluid dynamics (CFD) team for the National Aerospace Plane (NASP) program. This paper presents experimental results consisting of oil-flow and shadow graph flow-visualization photographs, afterbody surface-pressure distributions, rake boundary-layer measurements, Preston-tube skin-friction measurements, and flow field surveys with five-hole and thermocouple probes. The probe data consist of impact pressure, flow direction, and total temperature profiles in the interaction flow field.

Spaid, Frank W.; Keener, Earl R.; Hui, Frank C. L.

1995-01-01

76

Selected problems in experimental intermediate energy physics  

SciTech Connect

The objectives of this research program are to: investigate forefront problems in experimental intermediate energy physics; educate students in this field of research; and, develop the instrumentation necessary to undertake this experimental program. Generally, the research is designed to search for physical processes which cannot be explained by conventional models of elementary interactions. This includes the use of nuclear targets where the nucleus provides a many body environment of strongly perturbation of a known interaction by this environment. Unfortunately, such effects may be masked by the complexity of the many body problem and may be difficult to observe. Therefore, experiments must be carefully chosen and analyzed for deviations from the more conventional models. There were three major thrusts of the program; strange particle physics, where a strange quark is embedded in the nuclear medium; muon electro-weak decay, which involves a search for a violation of the standard model of the electro-weak interaction; and measurement of the spin dependent structure function of the neutron.

Mayes, B.W.; Hungerford, E.V.; Pinsky, L.S.

1990-09-01

77

High performance Doppler-inertial navigation-experimental results  

Microsoft Academic Search

This paper presents experimental results from a number of performance verification sea tests of the MARPOS(R) Doppler-inertial navigation system jointly implemented by Maridan A\\/S, Denmark, and the Technical University of Denmark for use onboard the MARIDAN series of AUVs. MARPOS(R) is a dead-reckoning based navigation system, the core of which is a state-of-the-art ring laser gyro (RLG) and a Doppler

Mikael Bliksted Larsen; Maridan AIS; Agem Alle

2000-01-01

78

Experimental results concerning global observables from the CERN SPS heavy ion program  

SciTech Connect

A brief overview is given of experimental results obtained during the initial operation of the heavy-ion program at the CERN SPS during the period 1986--1988. This paper confines itself to a presentation of results on so-called global observables, such as energy flow and multiplicity distributions, and on information extracted from them. Of particular interest among the latter are an estimate of the magnitude and spatial distribution of the energy density attained. 3 refs., 27 figs.

Young, G.R.

1990-06-01

79

Mechanical properties of triaxially braided composites: Experimental and analytical results  

NASA Technical Reports Server (NTRS)

The unnotched tensile properties of 2-D triaxial braid reinforced composites from both an experimental and an analytical viewpoint are studied. The materials are graphite fibers in an epoxy matrix. Three different reinforcing fiber architectures were considered. Specimens were cut from resin transfer molded (RTM) composite panels made from each braid. There were considerable differences in the observed elastic constants from different size strain gage and extensometer reading. Larger strain gages gave more consistent results and correlated better with the extensometer reading. Experimental strains correlated reasonably well with analytical predictions in the longitudinal, 0 degrees, fiber direction but not in the transverse direction. Tensile strength results were not always predictable even in reinforcing directions. Minor changes in braid geometry led to disproportionate strength variations. The unit cell structure of the triaxial braid was discussed with the assistance of computer analysis of the microgeometry. Photomicrographs of braid geometry were used to improve upon the computer graphics representations of unit cells. These unit cells were used to predict the elastic moduli with various degrees of sophistication. The simple and the complex analyses were generally in agreement but none adequately matched the experimental results for all the braids.

Masters, John E.; Foye, Raymond L.; Pastore, Christopher M.; Gowayed, Yasser A.

1992-01-01

80

Mechanical properties of triaxially braided composites: Experimental and analytical results  

NASA Technical Reports Server (NTRS)

This paper investigates the unnotched tensile properties of two-dimensional triaxial braid reinforced composites from both an experimental and analytical viewpoint. The materials are graphite fibers in an epoxy matrix. Three different reinforcing fiber architectures were considered. Specimens were cut from resin transfer molded (RTM) composite panels made from each braid. There were considerable differences in the observed elastic constants from different size strain gage and extensometer readings. Larger strain gages gave more consistent results and correlated better with the extensometer readings. Experimental strains correlated reasonably well with analytical predictions in the longitudinal, zero degree, fiber direction but not in the transverse direction. Tensile strength results were not always predictable even in reinforcing directions. Minor changes in braid geometry led to disproportionate strength variations. The unit cell structure of the triaxial braid was discussed with the assistence of computer analysis of the microgeometry. Photomicrographs of the braid geometry were used to improve upon the computer graphics representations of unit cells. These unit cells were used to predict the elastic moduli with various degrees of sophistication. The simple and the complex analyses were generally in agreement but none adequately matched the experimental results for all the braids.

Masters, John E.; Foye, Raymond L.; Pastore, Christopher M.; Gowayed, Yasser A.

1992-01-01

81

Experimental results on the enhanced backscatter phenomenon and its dynamics  

NASA Astrophysics Data System (ADS)

Enhanced backscatter effects have long been predicted theoretically and experimentally demonstrated. The reciprocity of a turbulent channel generates a group of paired rays with identical trajectory and phase information that leads to a region in phase space with double intensity and scintillation index. Though simulation work based on phase screen models has demonstrated the existence of the phenomenon, few experimental results have been published describing its characteristics, and possible applications of the enhanced backscatter phenomenon are still unclear. With the development of commercially available high powered lasers and advanced cameras with high frame rates, we have successfully captured the enhanced backscatter effects from different reflection surfaces. In addition to static observations, we have also tilted and pre-distorted the transmitted beam at various frequencies to track the dynamic properties of the enhanced backscatter phenomenon to verify its possible application in guidance and beam and image correction through atmospheric turbulence. In this paper, experimental results will be described, and discussions on the principle and applications of the phenomenon will be included. Enhanced backscatter effects are best observed in certain levels of turbulence (Cn 2?10-13 m-2/3), and show significant potential for providing self-guidance in beam correction that doesn't introduce additional costs (unlike providing a beacon laser). Possible applications of this phenomenon include tracking fast moving object with lasers, long distance (>1km) alignment, and focusing a high-power corrected laser beam over long distances.

Wu, Chensheng; Nelson, William; Ko, Jonathan; Davis, Christopher C.

2014-10-01

82

Experimental study of radiometric forces with comparison to computational results  

NASA Astrophysics Data System (ADS)

A study of the radiometric forces on heated plates has been conducted both experimentally and computationally. The experiments were carried out at USC in two vacuum chambers up to a maximum pressure of 6 Pa for various carrier gases. The computations were performed with both the DSMC and ES-BGK methods for a 2-D gas flow over a comparable range of pressures. It is shown that the radiometric devices provide maximum force at a Knudsen number approximating 0.1. Of the various gases tested, helium provides the largest peak force. Qualitatively, the experimental data and computational results are similar. A lack of experimental data on gas-surface accommodation and flow three-dimensionality yields up to a 40% difference in the magnitude of the measured and computed forces, but it is shown that this discrepancy can be used to predict accommodation values. Comparison of four geometric configurations has shown that the effect of the area is significant at pressures up to where the force is maximum. It is also demonstrated that the size of the chamber in which the radiometer resides is of primary importance, where the chamber dimensions are inversely related to the generated force. Finally, simulation of multi-vane configurations have shown that the optimal spacing of vanes can be tailored for specific uses; for maximum force production a tight spacing should be used, while maximum efficiency requires spacing on the order of a vane dimension. While the results so far are encouraging, they are far from complete. Further improvements would include: a new experimental setup to reduce uncertainty with highly accurate temperature control and measurement, an in situ way to prepare the surface as well as measure its cleanliness, and an in depth iterative computational study observing the impact of multiple radiometer vanes at numerous seperations.

Selden, Nathaniel P.

83

Medical waste to energy: experimental study  

PubMed Central

SUMMARY Objective. Although waste is traditionally assessed as a pollutant which needs to be reduced or lessened, its management is certainly necessary. Nowadays, biological fuel cells, through the direct conversion of organic matter to electricity using biocatalysts, represent a technology able to produce sustainable energy by means of waste treatment. This study aims to propose a mean to generate energy from blood and saliva, that are common risk-infectious medical waste. Materials and methods. Material employed (purchased by Sigma-Aldrich) were: Glucose oxidase (GOx), Nafion perfluorinated resin solution at 5% in a mixture of lower aliphatic alcohols and water, Polyethylene oxide. Stock solutions of D (+) glucose were prepared in a 0.1 M phosphate buffer solution and stored at 4 °C for at least 24 h before use. Carbon cloth electrode ELAT HT 140 E-W with a platinum loading of 5 gm-2 was purchased by E-Tek. Electrospun Nafion fibers were obtained as follows. Scanning electron microscopy was used to characterize the electrode morphologies. Results. In order to develop an effective immobilization strategy of GOx on the electrode surface, Nafion fibers (a fully fluorinated ion conducting polymer used as a membrane material in enzymatic fuel cells - EFC) were selected as immobilizing polymer matrix. In this work, exploiting the nafion fibers capability of being able to cathalize Gox activity, we have tried to produce an enzymatic fuel cell which could produce energy from the blood and the saliva within medical-dental waste. Conclusions. Medical waste refers to all those materials produced by the interaction among doctor and patient, such as blood and saliva. During our research we will try to complete an EFC prototype able to produce energy from blood and saliva inside the risk-infectious medical waste in order to contribute to the energy requirements of a consulting room. PMID:24971161

ARCURI, C.; LUCIANI, F.; PIVA, P.; BARTULI, F.N.; OTTRIA, L.; MECHERI, B.; LICOCCIA, S.

2013-01-01

84

Numerical and experimental studies of liquid storage tank thermal stratification for a solar energy system  

SciTech Connect

The results of theoretical and experimental studies of thermal stratification in liquid energy storage tanks for the performance of solar energy systems are presented. The investigation was divided into three areas: (1) Justification of the Importance of Thermal Stratification Inside the Energy Storage Tanks, (II) Development of a Simple Mathematical Model which is Compatible with Existing Solar Energy System Simulation Code, and (III) Validation of Mathematical Models by Experimental Data Obtained from Realistic Solar Energy System Operations.

Wu, S T; Han, S M

1980-11-01

85

Experimental study on a pendulum wave energy converter  

NASA Astrophysics Data System (ADS)

Many of the existing wave energy converters (WEC) are of oscillating water column (OWC) and point absorber (PA) types. Fewer references have been published in public on the pendulum type WEC. A series of experimental tests on a bottom-hinged pendulum WEC model are carried out and some results are revealed in the present study. The purpose of this paper is to present a detailed description of the tests. It is found that wave energy conversion efficiency varies with the applied damping and wave conditions. In addition, special attention is given to the effect of the water ballast on the efficiency of the wave energy converter. It is demonstrated that the ballast plays an important role in energy extraction. Better understanding on how the performance of the device is influenced by damping, wave height, wave period and ballast is shown.

Qiu, Shou-qiang; Ye, Jia-wei; Wang, Dong-jiao; Liang, Fu-lin

2013-06-01

86

Experimental study of low-energy charge transfer in nitrogen  

NASA Technical Reports Server (NTRS)

Total charge transfer cross sections were obtained for the N2(+)-N2 system with relative translational ion energies between 9 and 441 eV. Data were obtained to examine the dependence of total cross section on ion energy. The effect of ion excitation on the cross sections was studied by varying the electron ionization energy in the mass spectrometer ion source over an electron energy range between 14.5 and 32.1 eV. The dependence of total cross section on the neutralization chamber gas pressure was examined by obtaining data at pressure values from 9.9 to 0.000199 torr. Cross section values obtained were compared with experimental and theoretical results of other investigations.

Smith, A.

1979-01-01

87

Warm prestress modeling: Comparison of models and experimental results  

SciTech Connect

Warm prestress (WPS) behavior is the term commonly used to describe an apparent increase in material toughness of pressure vessel steels resulting from previous loading at a higher temperature. Such load histories are of interest largely due to the fact that loss of coolant accident (LOCA) and pressurized thermal shock (PTS) related load histories are expected to result in WPS behavior. While previous experimental work has demonstrated WPS behavior, insufficient attention has been given to separating material toughness variability for the WPS effect. There also appears to be a basic lack of understanding of the mechanism by which WPS behavior occurs and as a result, there is no generally accepted model or fracture criterion for predicting WPS behavior. The objectives of this study were to develop WPS data for which the enhanced toughness due to WPS could be separated from the K/sub Ic/ variability of the virgin material and to evaluate several candidate WPS models. 33 refs., 17 figs., 5 tabs.

Stonesifer, R.B.; Rybicki, E.F.; McCabe, D.E.

1989-04-01

88

Reproducibility of TLD systems - a comprehensive analysis of experimental results  

NASA Astrophysics Data System (ADS)

With respect to an application in the lower dose range, the statistical error of dose measurement has been investigated as a function of exposure by separating detector and reader dependent parameters such as PM dark current and zero dose reading, irradiation and annealing history of the dosimeter batch, batch uniformity, as well as the evaluation technique applied. The standard deviation vs. exposure curve can be interpreted on the basis of a complex two-parameter fit. Experimental results are discussed with respect to batch and reader dependent parameters.

Burgkhardt, B.; Piesch, E.

1980-09-01

89

Experimental feature in the primary-proton flux at energies above 10 TeV according to the results of searches for primary particles in nuclear emulsions exposed in the stratosphere (RUNJOB Experiment)  

SciTech Connect

In the RUNJOB experiment, a long-term exposure of x-ray emulsion chambers in the stratosphere from 1995 to 1999 with the aim of studying the composition and spectra of primary cosmic particles in the energy range 10-1000 TeV per nucleon revealed about 50% proton tracks. The remaining events of the proton group did not feature any candidate for a track of a singly charged particle within the search region determined from measurements of the coordinates of background nuclei going close to the sought track. Methodological factors that could explain this experimental observation are considered. A possible physical reason associated with the presence of a neutral component in the flux of primary protons in the energy region above 10 TeV is also analyzed.

Zayarnaya, I. S. [Russian Academy of Sciences, Lebedev Institute of Physics (Russian Federation)

2008-02-15

90

Single And Double Pulse Irradiation And Comparison With Experimental Results  

SciTech Connect

A theoretical model of laser ablation has been previously developed and applied to Laser Induced Breakdown Spectroscopy (LIBS) analysis of bronzes with the aim to improve quantitative results and to focus on problems arising in the interpretation of experimental data. The model describes laser-solid matter interaction, plume expansion, plasma formation and laser-plasma interaction. A two temperature approach has been also introduced to take into account the initial temperature dynamics of the alloy surface upon ultra-short laser irradiation. We examined various target compositions, typical of archaeological artworks, and different laser characteristics such as wavelength (355 nm, 530 nm, 1064 nm) and pulse duration (8 ns, 250 fs). In this work, the model has been extended to simulate double pulse LIBS configuration in order to clarify the mechanism involved in the process and for better interpreting the experimental data. Plasma composition, relevant parameters (temperature, electron density) and their kinetic evolutions have been measured. Results have been compared with the simulation obtained using the same irradiation conditions and set of targets.

Fornarini, L.; Fantoni, R.; Colao, F. [ENEA, FIM-FISLAS, Via E. Fermi 45, I-00044, Frascati (Italy); Santagata, A. [CNR-IMIP Unita Operativa di Potenza, Zona Industriale-85050 Tito Scalo (Italy); Teghil, R. [Universita degli Studi della Basilicata, Dip. Chimica, Via N. Sauro 85, 85100 Potenza (Italy)

2009-09-27

91

Atmospheric turbulence correction using digital holographic detection: experimental results.  

PubMed

The performance of long distance imaging systems is typically degraded by phase errors imparted by atmospheric turbulence. In this paper we apply coherent imaging methods to determine, and remove, these phase errors by digitally processing coherent recordings of the image data. In this manner we are able to remove the effects of atmospheric turbulence without needing a conventional adaptive optical system. Digital holographic detection is used to record the coherent, complex-valued, optical field for a series of atmospheric and object realizations. Correction of atmospheric phase errors is then based on maximizing an image sharpness metric to determine the aberrations present and correct the underlying image. Experimental results that demonstrate image recovery in the presence of turbulence are presented. Results obtained with severe turbulence that gives rise to anisoplanatism are also presented. PMID:19582079

Marron, Joseph C; Kendrick, Richard L; Seldomridge, Nathan; Grow, Taylor D; Höft, Thomas A

2009-07-01

92

Symposium on computing in experimental high energy physics  

NASA Astrophysics Data System (ADS)

This was the first symposium on computing in experimental high energy physics to be held during the ICCMSE conference. The symposium attracted 21 papers on a number of topics relevant for present day high energy physics experiments.

Bose, Tulika

2012-12-01

93

Interpretation of PISCES -- A RF antenna system experimental results  

SciTech Connect

The paper describes experimental data from rf coupling experiments using one to four coil antenna arrays that encircle a linear magnetized plasma column. Experimental results using single turn coil that produce symmetric (i.e. m = 0), dipole (m = 1), and radial rf magnetic fields for coupling to ion waves are compared. By operating without a Faraday shield, it was observed for the first time that the plasma resistive load seen by these different antenna types tends to increase with the number of turns to at least the second power. A four-turn m = 0 coil experienced a record 3--5 {Omega} loading, corresponding to over 90% power coupling to the plasma. A four-turn m = 1 coil experienced up to 1--1.5 {Omega} loading, also higher than previous observations. First time observations using a two coil array of m = 0 coil are also reported. As predicted, the loading decreases with increasing phase between coil from 0{degree} to 180{degree}. Experiments using four coil arrays were difficult to optimize and interpret primarily due to complexity of the manual tuning. To facilitate this optimization in the future, a proposed feedback control system that automatically matches load variations between 0.2 and 10 {Omega} is described.

Rothweil, D.A.; Phelps, D.A. [General Atomics, San Diego, CA (United States); Doerner, R. [Univ. of California, San Diego, CA (United States)

1995-10-01

94

Robotic follower experimentation results: ready for FCS increment I  

NASA Astrophysics Data System (ADS)

Robotics is a fundamental enabling technology required to meet the U.S. Army's vision to be a strategically responsive force capable of domination across the entire spectrum of conflict. The U. S. Army Research, Development and Engineering Command (RDECOM) Tank Automotive Research, Development & Engineering Center (TARDEC), in partnership with the U.S. Army Research Laboratory, is developing a leader-follower capability for Future Combat Systems. The Robotic Follower Advanced Technology Demonstration (ATD) utilizes a manned leader to provide a highlevel proofing of the follower's path, which operates with minimal user intervention. This paper will give a programmatic overview and discuss both the technical approach and operational experimentation results obtained during testing conducted at Ft. Bliss, New Mexico in February-March 2003.

Jaczkowski, Jeffrey J.

2003-09-01

95

Experimental Results of Rover-Based Coring and Caching  

NASA Technical Reports Server (NTRS)

Experimental results are presented for experiments performed using a prototype rover-based sample coring and caching system. The system consists of a rotary percussive coring tool on a five degree-of-freedom manipulator arm mounted on a FIDO-class rover and a sample caching subsystem mounted on the rover. Coring and caching experiments were performed in a laboratory setting and in a field test at Mono Lake, California. Rock abrasion experiments using an abrading bit on the coring tool were also performed. The experiments indicate that the sample acquisition and caching architecture is viable for use in a 2018 timeframe Mars caching mission and that rock abrasion using an abrading bit may be feasible in place of a dedicated rock abrasion tool.

Backes, Paul G.; Younse, Paulo; DiCicco, Matthew; Hudson, Nicolas; Collins, Curtis; Allwood, Abigail; Paolini, Robert; Male, Cason; Ma, Jeremy; Steele, Andrew; Conrad, Pamela G.

2011-01-01

96

Physical mechanism of comet outbursts - An experimental result  

NASA Technical Reports Server (NTRS)

Attention is given to an experimental investigation of the physical mechanism of comet outbursts which is consistent with the general picture of mantle presence on comets and clarifies the relation of mantles to eruptive activity. The experiment and closeup observation of Comet P/Halley suggest a result different from most mathematical models in that the release of gas pressure does not occur only from uniform gas flow out of the entire surface. In some active comets near perihelion within a few AU of the sun, gas production rates and disturbance of the surface may be so high that the outflow is nearly continuous, with the regolith being entirely stripped away, as in many of the models. The present model provides a cyclic eruption and recharge mechanism which is lacking in most other models.

Hartmann, William K.

1993-01-01

97

Experimental Results for Titan Aerobot Thermo-Mechanical Subsystem Development  

NASA Technical Reports Server (NTRS)

This paper describes experimental results from a development program focused in maturing Titan aerobot technology in the areas of mechanical and thermal subsystems. Results from four key activities are described: first, a cryogenic balloon materials development program involving coupon and cylinder tests and culminating in the fabrication and testing of an inflated 4.6 m long prototype blimp at 93 K; second, a combined lab experiment and numerical simulation effort to assess potential problems resulting from radioisotope thermal generator waste heat generation near an inflated blimp; third, an aerial deployment and inflation development program consisting of laboratory and helicopter drop tests on a near full scale (11 m long) prototype blimp; and fourth, a proof of concept experiment demonstrating the viability of using a mechanically steerable high gain antenna on a floating blimp to perform direct to Earth telecommunications from Titan. The paper provides details on all of these successful activities and discusses their impact on the overall effort to produce mature systems technology for future Titan aerobot missions.

Hall, Jeffrey L.; Jones, J. A.; Kerzhanovich, V. V.; Lachenmeier, T.; Mahr, P.; Pauken, M.; Plett, G. A.; Smith, L.; VanLuvender, M. L.; Yavrouian, A. H.

2006-01-01

98

Uncalibrated Building Energy Simulation Modeling Results  

E-print Network

of the ongoing monitoring of numerous campus buildings. Each building’s energy data were not made available until after the simulations and the analysis of the simulation results were completed. The energy use data were then compared to the simulated energy use...VOLUME 12, NUMBER 4 HVAC&R RESEARCH OCTOBER 2006 1141 Uncalibrated Building Energy Simulation Modeling Results Mushtaq Ahmad Charles H. Culp, PhD, PE Associate Member ASHRAE Fellow ASHRAE Received June 23, 2005; accepted April 17, 2006...

Ahmad, M.; Culp, C.H.

99

Experimental study of the effect of electromagnetic microwave radiation on parts made of high-energy polymer materials  

NASA Astrophysics Data System (ADS)

Results of experimental measurements of Young's modulus, burning rate, and specific heat of condensed high-energy polymer compositions (solid propellants) subjected to microwave radiation are reported. Experimental equipment and arrangement of experiments are described; the results obtained are analyzed.

Khimenko, L. L.; Rybakov, A. P.; Rybakov, N. A.; Kozlov, A. N.

2014-07-01

100

High frequency ultrasonic imaging of skin: experimental results.  

PubMed

Experimental results are presented demonstrating the application of pulse echo ultrasound to imaging the skin. A laboratory prototype B-mode mechanical scanner was employed to obtain images of human skin, both in vitro and in vivo, using broadband pulsed ultrasound at 25 MHz. Images were formed by processing digitized A-mode waveforms and displaying the resulting two-dimensional cross sections using a digital imaging system. Images obtained by rectifying the A-modes are compared to those derived using a software-based cross-correlation technique. Scans of test targets demonstrate that an axial resolution of 100 m can be achieved at 25 MHz when the digital correlation method is employed. Lateral resolution is limited by the 0.25 mm half-power focal beamwidth of the transducer. Seventeen in vitro ultrasonic scans of human skin were compared to frozen section histology. Average skin depth was well correlated between the two techniques ( = 0.99, p less than 0.001). Application of cross-correlated processing to 25 MHz in vivo images produced good delineation of epidermis, papillary, and reticular dermis. Conversion to a 50 MHz transducer did not delineate skin layers as well as the 25 MHz transducer due to inherent difficulties with transducer reverberations. PMID:6399171

Dines, K A; Sheets, P W; Brink, J A; Hanke, C W; Condra, K A; Clendenon, J L; Goss, S A; Smith, D J; Franklin, T D

1984-10-01

101

Energy Audit Results for Residential Building Energy Efficiency  

E-print Network

Energy Audit Results for Residential Building Energy Efficiency Forrest City Phases I and II This report analyses complete energy audit results from 28 homes within the Forest City residential complex. Relationships between temperature, humidity, comfort, and energy consumption are detailed. Recommendations

102

Shuttle Upper Atmosphere Mass Spectrometer Experimental Flight Results  

NASA Technical Reports Server (NTRS)

Calibrated pressure measurements for species with mass-to-charge ratios up to 50 amu/e(-) were obtained trom the shuttle upper atmosphere mass spectrometer experiment during re-entry on the STS-35 mission. The principal experimental objective is to obtain measurements of freestream density in the hypersonic rarefied flow flight regime. Data were collected from 180 to about 87 km. However, data above 115 km were contaminated from a source of gas emanating from pressure transdueers connected in parallel to the mass spectrometer. At lower altitudes, the pressure transducer data are compared to the mass spectrometer total pressure with excellent agreement. Near the orifice entrance, a significant amount of CO2 was generated from chemical reactions. The freestream density in the rarefied flow flight regime is calculated using an orifice pressure coefficient model based upon direct simulation Monte Carlo results. This density, when compared with the 1976 U.S. Standard Atmosphere model, exhibits the wavelike nature seen on previous flights using accelerometry. Selected spectra are presented at higher altitudes (320 km) showing the effects of the ingestion of gases from a forward fuselage fuel dump.

Blanchard, R. C.; Ozoroski, Thomas A.; Nicholson, John Y.

1994-01-01

103

Experimental evidence that evolutionarily diverse assemblages result in higher productivity  

PubMed Central

There now is ample experimental evidence that speciose assemblages are more productive and provide a greater amount of ecosystem services than depauperate ones. However, these experiments often conclude that there is a higher probability of including complementary species combinations in assemblages with more species and lack a priori prediction about which species combinations maximize function. Here, I report the results of an experiment manipulating the evolutionary relatedness of constituent plant species across a richness gradient. I show that assemblages with distantly related species contributed most to the higher biomass production in multispecies assemblages, through species complementarity. Species produced more biomass than predicted from their monocultures when they were in plots with distantly related species and produced the amount of biomass predicted from monoculture when sown with close relatives. This finding suggests that in the absence of any other information, combining distantly related species in restored or managed landscapes may serve to maximize biomass production and carbon sequestration, thus merging calls to conserve evolutionary history and maximize ecosystem function. PMID:23674676

Cadotte, Marc W.

2013-01-01

104

Experimental results of a 30 m, 3-core HTSC cable  

NASA Astrophysics Data System (ADS)

A high temperature superconducting (HTSC) cable is expected to transport large electric power with a compact size because of its high critical current density. We have been developing a 3-core 66 kV class HTSC cable, which is applied to the ?150 mm duct, and is composed of a conductor and a shield wound with Ag-Mn sheathed Bi-2223 tapes, electrical insulation with polypropylene laminated paper impregnated with liquid nitrogen and thermal insulation with co-axial corrugated pipes. A 30 m, 3-core cable system has been constructed to verify the 3-core performance after its production, laying and cooling. The cable had good performance to mechanical stress in the factory process. The critical current of the cable was more than 2.4 kA at 77 K. The AC loss of the conductor part was 0.5 W/m/phase at 1 kA rms, which agreed well with the calculated value of the spiral pitch adjustment technique. A 130 kV rms AC was successfully applied without any change in tan ? and capacitance. As a next step, a 100 m HTSC cable has been designed and developed based on these experimental results.

Masuda, Takato; Kato, Takeshi; Yumura, Hiroyasu; Hirose, Masayuki; Isojima, Shigeki; Honjo, Shoichi; Matsuo, Kimiyoshi; Mimura, Tomoo; Takahashi, Yoshihisa

2002-08-01

105

Experimental results of the European HELINOISE aeroacoustic rotor test  

NASA Astrophysics Data System (ADS)

In a cooperative research program between eight European partners, a 40% geometrically and dynamically scaled and highly instrumented model of the ECD (formerly MBB) BO 105 helicopter main rotor was tested in the open-jet anechoic test section of the German-Dutch Wind Tunnel (DNW) in the Netherlands. The primary objectives of this experimental study were to: (1) to improve the physical unsderstanding of the impulsive rotor noise sources by correlating blade pressure and acoustic character- istics, and (2) to provide an extensive airload and acoustic database for code validation purposes. Consequently, a compressive set of simultaneous acoustic and aerodynamic blade surface pressure data as well as blade dynamic and performance data were measured for the standard rotor with rectangular blade tips. In addition, initial quantitative information of the blade-vortex miss distance during blade-vortex interaction (BVI) was obtained. This paper describes the model and summarizes the aeroacoustic key results. The blade pressure chracteristics are examined to identify with the corresponding characteristics of the radiated sound pressure fields provide improved insight into the physics of the impulsive noise mechanisms. For descent flight, the strong change of BVI noise directivity and level with descent condition is illustrated, and the importance of the blade-vortex miss distance shown.

Splettstoesser, W. R.; Niesl, G.; Cenedese, F.; Nitti, F.; Papanikas, D. G.

1995-04-01

106

RHIC PC CNI POLARIMETER: EXPERIMENTAL SETUP AND PHYSICS RESULTS.  

SciTech Connect

Acceleration of polarized proton beams and experiments with them at RHIC require fast and reliable measurements of the polarization. The polarimeter presented here uses very high figure of merit of the elastic pC scattering at very low momenta transfer since the cross section is large. Small (a few percent) analyzing power of the reaction makes it necessary to collect about 10{sup 7} events per measurement. A deadtimeless DAQ system for the polarimeter is discussed in this paper. It is based on the waveform digitizer modules with ''on-board''' event analysis, resulting in typical polarization measurement times of several tens of seconds. During winter 2001/2002 RHIC polarized run several dedicated data runs were taken by the polarimeter to extract the form of the analyzing power dependence as a function of the momentum transferred at beam energies 24 and 100 GeV. This dependence is extremely important for the theoretical understanding of the CNI process including the contribution of the spin-flip hadronic amplitude. The new data may become an input to some theoretical models predicting the energy dependence of the analyzing power.

Alekseev, I G; Bunce, G; Cadman, R; Deshpande, A; Dhawan, S; Fields, D E; Huang, H; Hughes, V; Igo, G; Imai, K; Jinnouchi, O; Kanavets, V P; Kiryluk, J; Kurita, K; Li, Z; Lozowski, W; Mackay, W W; Makdisi, Y; Rescia, S; Roser, T; Saito, N; Spinka, H; Surrow, B; Svririda, D N; Tojo, J; Underwood, D

2002-09-09

107

Selected problems in experimental intermediate energy physics  

SciTech Connect

This report discusses progress in the following areas of intermediate energy physics; hyperon physics at the AGS; electroproduction of hypernuclei; test of the standard model of electroweak interactions; and spin structure function of the neutron. (LSP)

Mayes, B.W.; Hungerford, E.V.; Pinsky, L.S.

1990-09-01

108

Experimental results on combined ultraviolet-proton excitation of moon rock luminescence.  

NASA Technical Reports Server (NTRS)

The experimental results reported indicate that a small synergistic effect may exist between near-UV radiation and solar-wind-energy protons in solar radiation that could slightly enhance luminescence generation on the moon's surface. The magnitude of the effect, however, is far too small to account for the apparent orders-of-magnitude discrepancy between reported telescope measurements of lunar luminescence and the limitation of lunar luminescence intensity based on lab studies of moon rocks.

Nash, D. B.

1973-01-01

109

Can plumes collapse?: Experimental results and applications to Iceland.  

NASA Astrophysics Data System (ADS)

Iceland has produced magma in a series of episodic events. From lava chemistry it has been inferred that the plume temperature decreased over the first 5 Myr by ~50°C and for the next 3 Myr following continental break up it continued to oscillate by ~25°C. Such data has been used to infer possible episodic collapse of the Iceland plume. Collapsing plumes are not common fluid dynamical features. In thermochemical plumes it is possible to achieve collapse by varying the relative buoyancy due to chemistry and due to temperature. In thermal plumes however, with a constant heat source we would expect plumes not to collapse but to not continue to rise after reaching a point of neutral buoyancy. We expect thermal plumes, like those Earth's bottom thermal boundary layer is capable of producing, to either rise to the surface or be deflected but not to collapse. We have designed an experimental setup to investigate the conditions that may lead to collapse in thermal plumes with constant heat sources. We used high-Prandtl number fluids with strongly temperature-dependent viscosities (Lyle Golden syrup and Liquidose 436) as analogues to Earth's high viscosity mantle in a cubic Plexiglas tank (26.5cm inner sides), heated by a circular 2cm diameter heater (flat with the base of the tank). We explored ?Ts between 3-60°C. The flow was visualized with shadowgraphs and an automated -3D Stereoscopic Particle Image Velocimetry (SPIV) system to measure velocities. In Lyle's Golden Syrup collapse occurred at ?Ts as high as 8°C, while in Liquidose 436 the 8°C ?T run showed only partial collapse. The difference is not unexpected given the different physical properties. Partial collapse was seen even for ?Ts as high as 50°C. Both complete and partial collapse manifested themselves as downwelling flow in the central part of the conduit. Collapse stopped in the hotter plumes when the downwelling fluid met the hottest part of the conduit. The observed results suggest that diffusive time-scales are faster than the time-scales of buoyant rise. A naïve Rayleigh number analysis suggested that even a ?T as low as 1°C is above Rayleigh critical for the size of the convecting region. We will also present preliminary 3-D velocimetry results. Our results imply a much wider range of fluid dynamical behaviours for thermal plumes, which suggests that the dynamics of Earth plumes is probably not as straight-forward as previously hypothesised.

Pears, M.; Lithgow-Bertelloni, C.

2012-04-01

110

Mathematics of complexity in experimental high energy physics  

E-print Network

Mathematical ideas and approaches common in complexity-related fields have been fruitfully applied in experimental high energy physics also. We briefly review some of the cross-pollination that is occurring.

H. C. Eggers

2005-12-12

111

Numerical and Experimental Investigation of Tidal Current Energy Extraction   

E-print Network

Numerical and experimental investigations of tidal current energy extraction have been conducted in this study. A laboratory-scale water flume was simulated using commercial computational fluid dynamics (CFD) code FLUENT. ...

Sun, Xiaojing

2008-01-01

112

Experimental Wind Energy Unit in Northern Hungary  

Microsoft Academic Search

The dominant and well-usable wind channel comes from North-West through Hungary and leaving her in the South-East direction. Therefore, the city of Miskolc and its region are out of this significant wind energy flow. 4.5 meters per second of minimal wind speed is needed in any direction for acceptable operation of a wind turbine under 500 kilowatt power. In Sajokaza,

A. S. Varadi; J. Takacs

2007-01-01

113

Experimental investigations on energy harvesting performance of dielectric elastomers  

NASA Astrophysics Data System (ADS)

In this paper, the emerging technology of energy harvesting based on dielectric elastomers (DE), a new type of functional materials belonging to the family of Electroactive Polymers (EAPs), is presented with emphasis on its performance characteristics and some key influencing factors. At first, on the basic principle of DE energy harvesting, the effects of some control parameters are theoretically analyzed under certain mechanical and electrical constraints. Then, a type of annular DE generator using the commercial elastomers of VHB 4910 (3M, USA), is specially designed and fabricated. A series of experimental tests for the device's energy harvesting performance are implemented at different pre-stretch ratios, stretch amplitudes (displacements), and bias voltages in the constant charge (open-circuit) condition. The experiment results demonstrate the associated influence laws of the above control parameters on the performance of the DE generator, and have good consistent with those obtained from the theoretical analysis. This study is expected to provide a helpful guidance for the design and operation of practical DE energy harvesting devices/systems.

Wang, Yongquan; Liu, Xuejing; Xue, Huanhuan; Chen, Hualing; Jia, Shuhai

2014-03-01

114

Alkali Metal Backup Cooling for Stirling Systems - Experimental Results  

NASA Technical Reports Server (NTRS)

In a Stirling Radioisotope Power System (RPS), heat must be continuously removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS at the cost of an early termination of the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) can be used to passively allow multiple stops and restarts of the Stirling convertor. In a previous NASA SBIR Program, Advanced Cooling Technologies, Inc. (ACT) developed a series of sodium VCHPs as backup cooling systems for Stirling RPS. The operation of these VCHPs was demonstrated using Stirling heater head simulators and GPHS simulators. In the most recent effort, a sodium VCHP with a stainless steel envelope was designed, fabricated and tested at NASA Glenn Research Center (GRC) with a Stirling convertor for two concepts; one for the Advanced Stirling Radioisotope Generator (ASRG) back up cooling system and one for the Long-lived Venus Lander thermal management system. The VCHP is designed to activate and remove heat from the stopped convertor at a 19 degC temperature increase from the nominal vapor temperature. The 19 degC temperature increase from nominal is low enough to avoid risking standard ASRG operation and spoiling of the Multi-Layer Insulation (MLI). In addition, the same backup cooling system can be applied to the Stirling convertor used for the refrigeration system of the Long-lived Venus Lander. The VCHP will allow the refrigeration system to: 1) rest during transit at a lower temperature than nominal; 2) pre-cool the modules to an even lower temperature before the entry in Venus atmosphere; 3) work at nominal temperature on Venus surface; 4) briefly stop multiple times on the Venus surface to allow scientific measurements. This paper presents the experimental results from integrating the VCHP with an operating Stirling convertor and describes the methodology used to achieve their successful combined operation.

Schwendeman, Carl; Tarau, Calin; Anderson, William G.; Cornell, Peggy A.

2013-01-01

115

Alkali Metal Backup Cooling for Stirling Systems - Experimental Results  

NASA Technical Reports Server (NTRS)

In a Stirling Radioisotope Power System (RPS), heat must be continuously removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS at the cost of an early termination of the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) can be used to passively allow multiple stops and restarts of the Stirling convertor. In a previous NASA SBIR Program, Advanced Cooling Technologies, Inc. (ACT) developed a series of sodium VCHPs as backup cooling systems for Stirling RPS. The operation of these VCHPs was demonstrated using Stirling heater head simulators and GPHS simulators. In the most recent effort, a sodium VCHP with a stainless steel envelope was designed, fabricated and tested at NASA Glenn Research Center (GRC) with a Stirling convertor for two concepts; one for the Advanced Stirling Radioisotope Generator (ASRG) back up cooling system and one for the Long-lived Venus Lander thermal management system. The VCHP is designed to activate and remove heat from the stopped convertor at a 19 C temperature increase from the nominal vapor temperature. The 19 C temperature increase from nominal is low enough to avoid risking standard ASRG operation and spoiling of the Multi-Layer Insulation (MLI). In addition, the same backup cooling system can be applied to the Stirling convertor used for the refrigeration system of the Long-lived Venus Lander. The VCHP will allow the refrigeration system to: 1) rest during transit at a lower temperature than nominal; 2) pre-cool the modules to an even lower temperature before the entry in Venus atmosphere; 3) work at nominal temperature on Venus surface; 4) briefly stop multiple times on the Venus surface to allow scientific measurements. This paper presents the experimental results from integrating the VCHP with an operating Stirling convertor and describes the methodology used to achieve their successful combined operation.

Schwendeman, Carl; Tarau, Calin; Anderson, William G.; Cornell, Peggy A.

2013-01-01

116

Experimental Studies of Ion Beam Neutralization: Preliminary Results  

Microsoft Academic Search

A testing platform is designed to study ion beam neutralization in the mesothermal, collisionless region. In the experimental setup, argon neutrals were ionized in a microwave cavity and accelerated by a plasma lens system which was biased to 2500 V above the system ground. Electrons were boiled off from two hot tungsten filaments to neutralize the ion beam. The plasma

N. Ding; J. Polansky; R. Downey; J. Wang

2011-01-01

117

Compaction of lithic sands: Experimental results and applications  

Microsoft Academic Search

Compaction experiments showed that the degree of physical compaction of a lithic sand is related to the amount and type of lithic material present. Physical compaction models were developed based on experimental data from well-sorted lithic sandstones for which the percentage of preserved porosities were functions of the effective stress, the type of lithic material, and the quantity of lithic

E. D. Pittman; R. E. Larese

1991-01-01

118

CP Violation in B Meson Decays: Experimental Results  

SciTech Connect

CP violation is intimately connected with the puzzle of matter-antimatter asymmetry and baryogenesis. In the Standard Model of particle physics, the observed CP violation phenomena are accounted for by the Cabibbo-Kobayashi-Maskawa mechanism involving a phase in the quark mixing matrix. This paper is devoted to a review of the experimental status of CP violation in the decays of B mesons.

Lanceri, Livio; /Trieste U. /INFN, Trieste

2005-08-30

119

Experimental Results for an Annular Aerospike with Differential Throttling  

NASA Technical Reports Server (NTRS)

A) MSFC funded an internal study on Altitude Compensating Nozzles: 1) Develop an ACN design and performance prediction tool. 2) Design, build and test cold flow ACN nozzles. 3) An annular aerospike nozzle was designed and tested. 4) Incorporated differential throttling to assess Thrust Vector Control. B) Objective of the test hardware: 1) Provide design tool verification. 2) Provide benchmark data for CFD calculations. 3) Experimentally measure side force, or TVC, for a differentially throttled annular aerospike.

Ruf, Joseph H.; McDaniels, David M.

2005-01-01

120

Experimental results in optimal linear anti-windup compensation  

Microsoft Academic Search

The optimal anti-windup synthesis proposed by G. Grimm et al. (2001) is demonstrated on an experimental mechanical system. A windup-prone controller is first shown to induce severe performance degradation when saturation is hit. According to a linearized model of the mechanical system, static anti-windup compensation is infeasible, hence dynamic anti-windup of order equal to that of the plant is shown

Gene Grimm; Jay Hatfield; I. Postlethwaite; A. R. Teel; M. C. Turner; L. Zaccarian

2001-01-01

121

The mapping of electronic energy distributions using experimental electron density.  

PubMed

It is demonstrated that the approximate kinetic energy density calculated using the second-order gradient expansion with parameters of the multipole model fitted to experimental structure factors reproduces the main features of this quantity in a molecular or crystal position space. The use of the local virial theorem provides an appropriate derivation of approximate potential energy density and electronic energy density from the experimental (model) electron density and its derivatives. Consideration of these functions is not restricted by the critical points in the electron density and provides a comprehensive characterization of bonding in molecules and crystals. PMID:12149553

Tsirelson, Vladimir G

2002-08-01

122

An Experimental Study on Thermal Energy Storage Based Reverse Cycle Defrosting Method Using Subcooling Energy of Refrigerant for Air Source Heat Pump: Characteristics of Thermal Energy Storage Operation  

Microsoft Academic Search

the introduction introduction of the the system of thermal energy storage torage (TES) based reverse cycle defrosting method using sub-cooling energy of refrigerant for air Source heat eat p pump (ASHP) is given firstly. And And then the the characteristic of TES TES using sub-cooling energy of refrigerant in in heating is experimentally researched. The results results show that that

Dong Jiankai; Qu Minglu; Jiang Yiqiang; Yao Yang; Deng Shiming; Wang Honglei

2011-01-01

123

Aircrew dosimetry by means of experimental measurements and calculations: results obtained during the year 2003.  

PubMed

The results of measurements performed during the year 2003 onboard aircraft, mostly during regular commercial flights of the Czech Airlines (CSA) are presented. The studies were performed during more than 30 individual flights, several dosemeters and equipments were used for both neutron and non-neutron components of the onboard radiation field. CSA colleagues submitted us for all flights with navigation data necessary for the calculation of onboard aircraft crew exposure with transport codes EPCARD and CARI. Direct readings of experimental equipments were corrected on the base of the calibration in CERN high-energy radiation fields. A reasonable agreement of measured and calculated data was observed. During one of the flights, a very deep Forbush decrease occurred. The experimental results confronted with calculation permitted to obtain new view on the influence of such events on aircraft crew exposure. PMID:16604652

Spurný, F; B?gusová, M; Turek, K; Vlcek, B

2005-01-01

124

Experimental results and modelling of humidity control strategies for greenhouses in continental and coastal settings in the Mediterranean region. I: Experimental results and model development  

Microsoft Academic Search

Experimental strategies for controlling humidity were compared in a greenhouse sited in Madrid, a continental site in the Mediterranean region. Small roof window apertures significantly reduced the relative humidity with only a limited increase in associated energy consumption. A simplified climate model with four energy exchange terms (heating, insolation, losses through structure, and losses through windows) and three mass exchange

A. Perdigones; V. Valiño; J. L. García; F. Baptista; J. I. Montero; R. M. Benavente

125

Experimental overview of Generalized Parton Distribution results from HERMES  

SciTech Connect

Over the course of more than a decade the HERMES experiment has accumulated a wealth of data with electron and positron beams on various gaseous targets from Hydrogen up to Xenon. In addition, the beams and targets can be polarized. This data set is viewed in the context of Generalized Parton Distributions, a theoretical formalism with an explicit three dimensional view of the structure of the nucleon. It provides a link between experimental observables and the total angular momentum of the quarks in the nucleon.

Zihlmann, B. [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

2009-08-04

126

Experimental Studies of Ion Beam Neutralization: Preliminary Results  

SciTech Connect

A testing platform is designed to study ion beam neutralization in the mesothermal, collisionless region. In the experimental setup, argon neutrals were ionized in a microwave cavity and accelerated by a plasma lens system which was biased to 2500 V above the system ground. Electrons were boiled off from two hot tungsten filaments to neutralize the ion beam. The plasma is diagnosed using Langmuir probe and Faraday probe. A 3-D traversing system and a complete data acquisition loop were developed to efficiently measure 3-D beam profile. Preliminary measurements of beam profiles are presented for different operating conditions.

Ding, N.; Polansky, J.; Downey, R.; Wang, J. [Department of Astronautical Engineering, University of Southern California, Los Angeles, CA 90089-1192 (United States)

2011-05-20

127

Optimal active vibration absorber: Design and experimental results  

NASA Technical Reports Server (NTRS)

An optimal active vibration absorber can provide guaranteed closed-loop stability and control for large flexible space structures with collocated sensors/actuators. The active vibration absorber is a second-order dynamic system which is designed to suppress any unwanted structural vibration. This can be designed with minimum knowledge of the controlled system. Two methods for optimizing the active vibration absorber parameters are illustrated: minimum resonant amplitude and frequency matched active controllers. The Controls-Structures Interaction Phase-1 Evolutionary Model at NASA LaRC is used to demonstrate the effectiveness of the active vibration absorber for vibration suppression. Performance is compared numerically and experimentally using acceleration feedback.

Lee-Glauser, Gina; Juang, Jer-Nan; Sulla, Jeffrey L.

1992-01-01

128

Laser ablation of a turbid medium: Modeling and experimental results  

SciTech Connect

Q-switched Nd:YAG laser ablation of a turbid medium (paint) is studied. The optical properties (absorption coefficient, scattering coefficient, and its anisotropy) of a paint are determined with a multiple scattering model (three-flux model), and from measurements of reflection-transmission of light through thin layers. The energy deposition profiles are calculated at wavelengths of 532 nm and 1.064 {mu}m. They are different from those described by a Lambert-Beer law. In particular, the energy deposition of the laser beam is not maximum on the surface but at some depth inside the medium. The ablated rate was measured for the two wavelengths and compared with the energy deposition profile predicted by the model. This allows us to understand the evolution of the ablated depth with the wavelength: the more the scattering coefficient is higher, the more the ablated depth and the threshold fluence of ablation decrease.

Brygo, F.; Semerok, A.; Weulersse, J.-M.; Thro, P.-Y.; Oltra, R. [Commissariat a l'Energie Atomique, DEN/DANS/DPC/SCP/LILM, Batiment 467, 91191 Gifs/Yvette (France); LRRS-UMR 5613 CNRS, Universite de Bourgogne 21078 Dijon (France)

2006-08-01

129

Thermodynamics of sodium feldspar II: Experimental results and numerical calculations  

Microsoft Academic Search

The free energy, entropy and enthalpy of sodium feldspar in thermal equilibrium and in metastable states are derived from investigations of the heat capacities of albite, analbite, ordered and disordered Or31. The lattice strains of all stable and metastable states are calculated from the two-order parameter theory published in the preceding paper. This approach also allows one to distinguish between

E. Salje; B. Kuscholke; B. Wruck; H. Kroll

1985-01-01

130

Modeling and experimental characterization of a fluttering windbelt for energy harvesting  

NASA Astrophysics Data System (ADS)

Wind energy harvesters based on fluttering offer a valuable and efficient alternative to the traditional wind turbines. A longer life expectancy and cheaper fabrication is attained through the absence of gears or bearings. This article presents the theoretical and experimental study of a novel windbelt-based energy harvester, designed to harvest from continuously changing low-speed winds. A theoretical model is derived to explore the scaling effect on the critical flutter frequency, and experimental results validate the theoretical predictions.

Arroyo, E.; Foong, S.; Wood, K. L.

2014-11-01

131

Guided wave modes in porous cylinders: Experimental results  

NASA Astrophysics Data System (ADS)

In this paper guided wave modes in porous media are investigated. A water-saturated porous cylinder is mounted in the test section of a shock tube. Between the porous sample and the wall of the shock tube a water-filled annulus exists. For very small annulus width, bulk waves are generated and one-dimensional modeling is sufficient. Otherwise two-dimensional effects become important and multiple guided wave modes occur. Using a newly developed traversable positioning system in the shock tube, the frequency-dependent phase velocities and damping coefficients in the 1-120 kHz frequency range were measured. Prony's method was used for data processing. Agreement was found between the experimental data and the two-dimensional modeling of the shock tube which was based on Biot's theory. copyright 2002 Acoustical Society of America.

Wisse, C. J.; Smeulders, D. M. J.; van Dongen, M. E. H.; Chao, G.

2002-09-01

132

Experimental verification of Santilli`s clean, subnuclear, hadronic energy  

SciTech Connect

The structure of the nucleus and its constituents still presents a challenge to both theoretical and experimental physicists. This paper deals mainly with the an experimental attempt for the verification of the new theory for neutron structure and its stimulated decay recently proposed by R.M. Santilli which would imply a new, clean, subnuclear energy. The experiment is carried out by the Laboratory of Nuclear Technology at the University of Thrace, Xanthi, Greece.

Tsagas, N.F.; Mystakidis, A.; Bakos, G. [Democritus Univ. of Thrace, Xanthi (Greece)] [and others

1996-02-01

133

Fracture mechanics analysis of composite microcracking - Experimental results in fatigue  

NASA Technical Reports Server (NTRS)

The Nairn (1989) variational mechanics analysis, which yields the energy release rate of a microcrack's formation between two existing microcracks, has proven useful in the fracture mechanics interpretation of cross-ply laminates' microcracking. Attention is presently given to the application of this energy release rate analysis to a fracture mechanics-based interpretation of microcrack formation during fatigue loading, for the case of fatigue experiments on three layups of Avimid K/IM6 laminates and four layups of Fiberite 934/T300 laminates. The single master Paris-law plot onto which the data from all layups of a given material system fall is claimed to offer a complete characterization of that system's microcrack-formation resistance during fatigue loading.

Nairn, J. A.; Liu, S.

1990-01-01

134

Experimental and theoretical research in high energy astrophysics  

NASA Technical Reports Server (NTRS)

NASA grants to MIT for investigations in experimental and theoretical high energy astrophysics have, over the years, nurtured the infrastructure development and experimental activities that have led to successful proposals for the OSO 7, SAS 3, HEAO 1, and HEAO 2 missions and to the achievements in high energy astrophysics of the MIT Group. This report consists of excerpts from the progress reports of 1988 through 1990 that have been submitted as a regular feature of the renewal requests. These excerpts convey the flavor of the grant-supported activities, and a sense of the progress that has been made in each of the areas investigations.

Clark, George W.

1990-01-01

135

Construction of a WMR for Trajectory Tracking Control: Experimental Results  

PubMed Central

This paper reports a solution for trajectory tracking control of a differential drive wheeled mobile robot (WMR) based on a hierarchical approach. The general design and construction of the WMR are described. The hierarchical controller proposed has two components: a high-level control and a low-level control. The high-level control law is based on an input-output linearization scheme for the robot kinematic model, which provides the desired angular velocity profiles that the WMR has to track in order to achieve the desired position (x?, y?) and orientation (??). Then, a low-level control law, based on a proportional integral (PI) approach, is designed to control the velocity of the WMR wheels to ensure those tracking features. Regarding the trajectories, this paper provides the solution or the following cases: (1) time-varying parametric trajectories such as straight lines and parabolas and (2) smooth curves fitted by cubic splines which are generated by the desired data points {(x1?, y1?),..., (xn?, yn?)}. A straightforward algorithm is developed for constructing the cubic splines. Finally, this paper includes an experimental validation of the proposed technique by employing a DS1104 dSPACE electronic board along with MATLAB/Simulink software. PMID:23997679

Silva-Ortigoza, R.; Márquez-Sánchez, C.; Marcelino-Aranda, M.; Marciano-Melchor, M.; Silva-Ortigoza, G.; Bautista-Quintero, R.; Ramos-Silvestre, E. R.; Rivera-Díaz, J. C.; Muñoz-Carrillo, D.

2013-01-01

136

Construction of a WMR for trajectory tracking control: experimental results.  

PubMed

This paper reports a solution for trajectory tracking control of a differential drive wheeled mobile robot (WMR) based on a hierarchical approach. The general design and construction of the WMR are described. The hierarchical controller proposed has two components: a high-level control and a low-level control. The high-level control law is based on an input-output linearization scheme for the robot kinematic model, which provides the desired angular velocity profiles that the WMR has to track in order to achieve the desired position (x?, y?) and orientation (??). Then, a low-level control law, based on a proportional integral (PI) approach, is designed to control the velocity of the WMR wheels to ensure those tracking features. Regarding the trajectories, this paper provides the solution or the following cases: (1) time-varying parametric trajectories such as straight lines and parabolas and (2) smooth curves fitted by cubic splines which are generated by the desired data points {(x??, y??),..., (x(n)?, y(n)?)}. A straightforward algorithm is developed for constructing the cubic splines. Finally, this paper includes an experimental validation of the proposed technique by employing a DS1104 dSPACE electronic board along with MATLAB/Simulink software. PMID:23997679

Silva-Ortigoza, R; Márquez-Sánchez, C; Marcelino-Aranda, M; Marciano-Melchor, M; Silva-Ortigoza, G; Bautista-Quintero, R; Ramos-Silvestre, E R; Rivera-Díaz, J C; Muñoz-Carrillo, D

2013-01-01

137

EXPERIMENTAL RESULTS FROM A MICROWAVE CAVITY BEAM POSITION MONITOR.  

SciTech Connect

Future Linear Colliders have hard requirements for the beam transverse position stability in the accelerator. A beam Position Monitor (BPM) with the resolution better than 0.1 micron in the single bunch regime is needed to control the stability of the beam position along the linac. Proposed BPM is based on the measurement of the asymmetrical mode excited by single bunch in the cavity. Four stages of signal processing (space-, time-, frequency- and phase-filtering providing the required signal-to-noise ratio) are used to obtain extremely high resolution. The measurement set-up was designed by BINP and installed at ATF/BNL to test experimentally this concept. The set-up includes three two-coordinates BPM's at the frequency of 13.566 GHz, and reference intensity/phase cavity. BPM's were mounted on support table. The two-coordinates movers allow to move and align BPM's along the straight line, using the signals from the beam. The position of each monitor is controlled by the sensors with the accuracy 0.03 micron. The information from three monitors allows to exclude angle and position jitter of the beam and measure BPM resolution. In the experiments the resolution of about 0.15 micron for 0.25 nC beam intensity was obtained, that is close to the value required.

BALAKIN,V.; BAZHAN,A.; LUNEV,P.; SOLYAK,N.; VOGEL,V.; ZHOGOLEV,P.; LISITSYN,A.; YAKIMENKO,V.

1999-03-29

138

Experimental results with hydrogen fueled internal combustion engines  

NASA Technical Reports Server (NTRS)

The paper focuses on the most important experimental findings for hydrogen-fueled internal combustion engines, with particular reference to the application of these findings to the assessment of the potential of hydrogen engines. Emphasis is on the various tradeoffs that can be made, such as between maximum efficiency, maximum power, and minimum NO emissions. The various possibilities for induction and ignition are described. Some projections are made about areas in which hydrogen engines may find their initial application and about optimum ways to design such engines. It is shown that hydrogen-fueled reciprocal internal combustion engines offer important advantages with respect to thermal efficiency and exhaust emissions. Problems arising from preignition can suitably be avoided by restricting the fuel-air equivalence ratio to values below about 0.5. The direct cylinder injection appears to be a very attractive way to operate the engine, because it combines a wide range of possible power outputs with a high thermal efficiency and very low NO emissions at part loads.

De Boer, P. C. T.; Mclean, W. J.; Homan, H. S.

1975-01-01

139

Modeling of rock friction 1. Experimental results and constitutive equations  

USGS Publications Warehouse

Direct shear experiments on ground surfaces of a granodiorite from Raymond, California, at normal stresses of ??6 MPa demonstrate that competing time, displacement, and velocity effects control rock friction. It is proposed that the strength of the population of points of contacts between sliding surfaces determines frictional strength and that the population of contacts changes continuously with displacements. Previous experiments demonstrate that the strength of the contacts increases with the age of the contacts. The present experiments establish that a characteristic displacement, proportional to surface roughness, is required to change the population of contacts. Hence during slip the average age of the points of contact and therefore frictional strength decrease as slip velocity increases. Displacement weakening and consequently the potential for unstable slip occur whenever displacement reduces the average age of the contacts. In addition to this velocity dependency, which arises from displacement dependency and time dependency, the experiments also show a competing but transient increase in friction whenever slip velocity increases. Creep of the sliding surface at stresses below that for steady state slip is also observed. Constitutive relationships are developed that permit quantitative simulation of the friction versus displacement data as a function of surface roughness and for different time and velocity histories. Unstable slip in experiments is controlled by these constitutive effects and by the stiffness of the experimental system. It is argued that analogous properties control earthquake instability. Copyright ?? 1979 by the American Geophysical Union.

Dieterich, J.H.

1979-01-01

140

Flow Measurement with Tangential Paddlewheel Flow Meters: Analysis of Experimental Results and in-situ Diagnostics  

E-print Network

following a screen mesh and tube bank flow straightener set-up was used to insure fully developed turbulent flow (Baker and Hurley 1984). Velocity profiles, obtained by traversing the test section using 1/16" diameter pitot tube, are shown in Figure 7. A...Proceedings of the 16th Annual Industrial Energy Technology Conference 1994, Houston, TX pp. 252-260 ESL-PA-94/04-02 REPRINTED WITH PERMISSION FLOW MEASUREMENT WITH TANGENTIAL PADDLEWHEEL FLOW METERS: ANALYSIS OF EXPERIMENTAL RESULTS AND IN...

Watt, J. B.; Haberl, J. S.

141

Experimental Studies of Elementary Particle Interactions at High Energies  

SciTech Connect

This is the final report of a program of research on ``Experimental Studies of Elementary Particle Interactions at High Energies'' of the High Energy Physics (HEP) group of The Rockefeller University. The research was carried out using the Collider Detector at Fermilab (CDF) and the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) at CERN. Three faculty members, two research associates, and two postdoctoral associates participated in this project. At CDF, we studied proton-antiproton collisions at an energy of 1.96 TeV. We focused on diffractive interactions, in which the colliding antiproton loses a small fraction of its momentum, typically less than 1%, while the proton is excited into a high mass state retaining its quantum numbers. The study of such collisions provides insight into the nature of the diffractive exchange, conventionally referred to as Pomeron exchange. In studies of W and Z production, we found results that point to a QCD-based interpretation of the diffractive exchange, as predicted in a data-driven phenomenology developed within the Rockefeller HEP group. At CMS, we worked on diffraction, supersymmetry (SUSY), dark matter, large extra dimensions, and statistical applications to data analysis projects. In diffraction, we extended our CDF studies to higher energies working on two fronts: measurement of the single/double diffraction and of the rapidity gap cross sections at 7 TeV, and development of a simulation of diffractive processes along the lines of our successful model used at CDF. Working with the PYTHIA8 Monte Carlo simulation authors, we implemented our model as a PYTHIA8-MBR option in PYTHIA8 and used it in our data analysis. Preliminary results indicate good agreement. We searched for SUSY by measuring parameters in the Constrained Minimal Supersymmetric extension of the Standard Model (CMSSM) and found results which, combined with other experimental constraints and theoretical considerations, indicate that the CMSSM is not a viable model. Expressing our results in terms of simple topologies, we exclude squark masses below 0.75 TeV and gluino masses below 1.1 TeV. Astrophysical measurements suggest that about 80% of the matter density of the Universe is non-luminous. One of the theories on dark matter attributes it to Weakly Interacting Massive Particles (WIMPs). We searched for WIMPs in 7 TeV and 8 TeV collisions at CMS and set limits on WIMP production rates, which are competitive and complementary to those of direct detection experiments. Searching for monojets (events with only one jet), which in a popular model could be produced by a jet paired by a gravitino that escapes into extra dimensions, we significantly improved the previously set limit. Our results have been used to set limits on Higgs decay to invisible particles and on production of top squarks in compressed SUSY scenarios. Statistics. We computed Bayesian reference priors for several types of measurement and used them in the analysis of CMS data; investigated the applicability of bootstrap methods to HEP measurements; studied several issues associated with simple-versus-simple hypothesis testing and applied the resulting methods to the measurement of some properties of the top quark and Higgs boson.

Goulianos, Konstantin [The Rockefeller University] [The Rockefeller University

2013-07-31

142

Experimental efforts and results in finding new heavy scintillators  

SciTech Connect

New heavy scintillators are being discovered with increasing frequency. In recent years NaI(Tl) (with its high light output and energy resolution) has been joined by BGO (with its high stopping power), BaF{sub 2} (with its excellent timing resolution), and CeF{sub 3} (with its speed and short Moliere radius). More than 10 potentially useful scintillators have been under development in the past five years, such as PbSO{sub 4} and Lu{sub 2}SiO{sub 5}(Ce). We tabulate the characteristics of these and other scintillators, including wavelength, luminous efficiency, decay time, and initial intensity. We describe a search strategy and the prospects for finding the ``ideal`` heavy scintillator, which would combine the light output of NaI(Tl) and CsI(Tl), the stopping power of BGO, and the speed of BaF{sub 2} and ZnO(Ga).

Derenzo, S.E.; Moses, W.W.

1992-09-01

143

Experimental results of USSR nuclear explosion decoupling measurements  

SciTech Connect

This report was presented at the 14th annual PL/DARPA Seismic Research Symposium on September 16, 1992. In it, we describe a decoupling experiment undertaken by the former Soviet Union at Azghir, north of the Caspian Sea. The properties of the cavity are given, including a rough description of the geology (salt-dome overlain by 275 m radius sphere, 987 m deep), velocities, densities, etc. These shots had larger yields than the Salmon-Sterling decoupling experiments undertaken by the U.S. in the mid-sixties. Like the U.S. experiment, this Soviet experiment did not achieve full decoupling. The energy decoupling factor (computed from statistical relationships between the yield and amplitude-distance curves rather than spectra) increased to a maximum of 30 as distance increase. Based on our observations and theoretical limits to decoupling, we conclude that a fully decoupled 1 kt explosion could be observed at a distance of 2,500 km.

Adushkin, V.V.; Kitov, I.O.; Sultanov, D.D.

1992-09-01

144

Experimental results and modeling of a dynamic hohlraum on SATURN  

SciTech Connect

Experiments were performed at SATURN, a high current z-pinch, to explore the feasibility of creating a hohlraum by imploding a tungsten wire array onto a low-density foam. Emission measurements in the 200--280 eV energy band were consistent with a 110--135 eV Planckian before the target shock heated, or stagnated, on-axis. Peak pinch radiation temperatures of nominally 160 eV were obtained. Measured early time x-ray emission histories and temperature estimates agree well with modeled performance in the 200--280 eV band using a 2D radiation magneto-hydrodynamics code. However, significant differences are observed in comparisons of the x-ray images and 2D simulations.

Derzon, M.S.; Allshouse, G.O.; Deeney, C.; Leeper, R.J.; Nash, T.J. [Sandia National Labs., Albuquerque, NM (United States); Matuska, W.; Peterson, D.L. [Los Alamos National Lab., NM (United States); MacFarlane, J.J. [Univ. of Wisconsin, Madison, WI (United States); Ryutov, D.D. [Lawrence Livermore National Lab., CA (United States)

1998-06-01

145

Experimental Review of New Results on Hadron Spectroscopy  

NASA Astrophysics Data System (ADS)

In this talk, I will review the most important progress in the field of hadron spectroscopy in recent one year, especially on multi-quark candidates, including pentaquarks, X(3872), Ds(2632) and resonant structures near p bar {p}, pbar {? }, bar{p}Lambda_{c}, K^{-}bar{Lambda}$ and ?J/? mass thresholds. I will also review the new results on scalar mesons, including ?,K, f0(980), f0(1370), f0(1500) and possible f0(1790). This talk will also cover some other interesting results from BES and CLEO-c experiments.

Jin, Shan

2005-04-01

146

Joint Soviet-American experiment on hypokinesia: Experimental results  

NASA Technical Reports Server (NTRS)

Comprehensive results are reported from the Soviet portion of a joint Soviet-American experiment involving hypokinesia. The main emphases are on chemical analyses of blood and urine, functional tests, and examination of the cardiovascular system by electrocardiography, echocardiography, and plethysmography.

Burovskiy, N. N.

1979-01-01

147

FROV: a distributed broadcast protocol for VANET experimental results  

Microsoft Academic Search

We present a distributed fast protocol for broadcast in ad hoc vehicular networks, and the results of a set of experiments that we carried to test it. Our proposal, called FROV, gains optimal performance in very reasonable real scenarios. These scenario are challenging and were not extensively studied in literature. In particular, we consider individual and variable transmission ranges of

Alessandro Amoroso; Luca Gandolfi; Simone Grassilli; Marco Roccetti

2009-01-01

148

Vegetated Roof Water-Balance Model: Experimental and Model Results  

E-print Network

resolution. Overall, the results show that the average stormwater runoff reduction was 32% for the study coefficient of 0.53 for the study's sedum canopy in which the onset of stomatal closure occurs when the soil decrease linearly with declining soil wetness. The VR-WBM does an excellent job predicting runoff (R2 ¼ 0

149

Potential for hot-dry-rock geothermal resources: Experimental results  

NASA Astrophysics Data System (ADS)

Hot dry rock (HDR) contains insufficient permeability and fluid for natural hydrothermal development, but water pumped in a circulation loop through a HDR reservoir (hydraulically fractured between two drill holes) is being tested and evaluated. The formation of such in situ heat transfer systems, and subsequent testing of the man-made geothermal reservoirs in the Jemez volcanic field, New Mexico have already indicated the technical feasibility of the hot dry rock (HDR) geothermal concept. Documented production history and heat-extraction data obtained during the period from 1978 to 1980 have confirmed heat transfer, low water loss, and predictable thermal drawdown models for the HDR systems. During a nine month test of closed-loop heat extraction operations, 15 x 10 to the 6th power kWh of thermal energy were produced. The effective heat-transfer area and volume of the reservoir increased due to secondary fracturing caused by thermal contraction of the reservoir rock, and sustained pressurization. Drilling, fracturing, and testing of a larger, hotter reservoir system is now underway on a HDR geothermal reservoir of commercial size.

Rowley, J. C.; Heiken, G.; Murphy, H. D.; Kuriyagawa, M.

150

Delaminations in composite plates under transverse static loads - Experimental results  

NASA Technical Reports Server (NTRS)

Tests were performed measuring the damage initiation loads and the locations, shapes, and sizes of delaminations in Fiberite T300/976 graphite/epoxy, Fiberite IM7/977-2 graphite-toughened epoxy, and ICI APC-2 graphite-PEEK plates subjected to transverse static loads. The data were compared to the results of the Finn-Springer model, and good agreements were found between the measured and calculated delamination lengths and widths.

Finn, Scott R.; He, Yi-Fei; Springer, George S.

1992-01-01

151

Augmented dry cooling surface test program: analysis and experimental results  

Microsoft Academic Search

Experiments were performed to assess the operating characteristics and potential performance of water-augmented dry cooling systems. The work was aimed at evaluating a deluged air-cooled HOETERV plate fin heat exchanger surface proposed for integrated dry\\/wet cooling systems and using test results to guide the development of a predictive analytical model. In the process, all-dry performance data were obtained for the

H. L. Parry; L. J. MacGowan; D. K. Kreid; L. E. Wiles; D. W. Faletti; B. M. Johnson

1979-01-01

152

Parallel and Distributed Computational Fluid Dynamics: Experimental Results and Challenges  

NASA Technical Reports Server (NTRS)

This paper describes several results of parallel and distributed computing using a large scale production flow solver program. A coarse grained parallelization based on clustering of discretization grids combined with partitioning of large grids for load balancing is presented. An assessment is given of its performance on distributed and distributed-shared memory platforms using large scale scientific problems. An experiment with this solver, adapted to a Wide Area Network execution environment is presented. We also give a comparative performance assessment of computation and communication times on both the tightly and loosely-coupled machines.

Djomehri, Mohammad Jahed; Biswas, R.; VanderWijngaart, R.; Yarrow, M.

2000-01-01

153

Delaminations in composite plates under transverse impact loads - Experimental results  

NASA Technical Reports Server (NTRS)

Tests were performed measuring the locations and geometries of delaminations in Fiberite T300/976 graphite/epoxy, Fiberite IM7/977-2 graphite-toughened epoxy, and ICI APC-2 graphite/PEEK plates subjected to transverse impact loads. The data provide specific information on the effects of impactor velocity, impactor mass, material, thickness of back ply group, difference in fiber orientation between adjacent ply groups, plate thickness, and impactor nose radius. The data were compared to the results of the Finn-Springer model. The model was found to describe the data with reasonable accuracy.

Finn, Scott R.; He, Ye-Fei; Springer, George S.

1993-01-01

154

Persistent GMTI surveillance: theoretical performance bounds and some experimental results  

NASA Astrophysics Data System (ADS)

In certain operational radar modes, slow ground moving targets are detected over several processing intervals using space-time adaptive processing. This enables use of Bayesian filtering and smoothing algorithms for estimation of time-varying moving target parameters. In this paper, some Bayesian filtering algorithms are investigated. The Cra?er-Rao bounds based on subsets of radar measurements (range, angle and Doppler) are derived for typical maneuvering targets and compared against simulated results from Bayesian filters. The performance is also evaluated using real data obtained from DRDC Ottawa's XWEAR radar.

Balaji, Bhashyam; Damini, Anthony; Wang, Kai

2010-04-01

155

Experimental test accelerator: description and results of initial experiments  

SciTech Connect

The ETA is a high current (10,000 Amp) linear induction accelerator that produces short (30 ns) pulses of electrons at 5 MeV twice per second or in bursts of 5 pulses separated by as little as one millisecond. At this time the machine has operated at 65% of its design current and 90% of the design voltage. This report contains a description of the accelerator and its diagnostics; the results of the initial year of operation; a comparison of design codes with experiments on beam transport; and a discussion of some of the special problems and their status.

Fessenden, T.; Birx, D.; Briggs, R.

1980-06-02

156

Experimental results of a propeller/wing interaction study  

NASA Technical Reports Server (NTRS)

Steady state measurements have been performed on a propellar and a wing in a tractor configuration, to investigate the consequences of mutual interference on overall performance. For certain geometries wing lift is found to be enhanced, and wing drag to be decreased. The unsteady nature of the propeller-wing aerodynamic interaction has been studied using flow visualization. Results obtained indicate that the tip vortex is severed at the wing leading edge, the severed tip vortex filaments shear in a spanwise direction relative to one another, and these displaced filaments deform to reconnect at the trailing edge.

Johnson, Robert T.; Sullivan, John P.; Witkowski, David P.

1991-01-01

157

Wide-field Fizeau imaging telescope: experimental results.  

PubMed

A nine-aperture, wide-field Fizeau imaging telescope has been built at the Lockheed-Martin Advanced Technology Center. The telescope consists of nine, 125 mm diameter collector telescopes coherently phased and combined to form a diffraction-limited image with a resolution that is consistent with the 610 mm diameter of the telescope. The phased field of view of the array is 1 murad. The measured rms wavefront error is 0.08 waves rms at 635 nm. The telescope is actively controlled to correct for tilt and phasing errors. The control sensing technique is the method known as phase diversity, which extracts wavefront information from a pair of focused and defocused images. The optical design of the telescope and typical performance results are described. PMID:16778931

Kendrick, R L; Aubrun, Jean-Noel; Bell, Ray; Benson, Robert; Benson, Larry; Brace, David; Breakwell, John; Burriesci, Larry; Byler, Eric; Camp, John; Cross, Gene; Cuneo, Peter; Dean, Peter; Digumerthi, Ramji; Duncan, Alan; Farley, John; Green, Andy; Hamilton, Howard H; Herman, Bruce; Lauraitis, Kris; de Leon, Erich; Lorell, Kenneth; Martin, Rob; Matosian, Ken; Muench, Tom; Ni, Mel; Palmer, Alice; Roseman, Dennis; Russell, Sheldon; Schweiger, Paul; Sigler, Rob; Smith, John; Stone, Richard; Stubbs, David; Swietek, Gregg; Thatcher, John; Tischhauser, C; Wong, Harvey; Zarifis, Vassilis; Gleichman, Kurt; Paxman, Rick

2006-06-20

158

New experimental results in atlas-based brain morphometry  

NASA Astrophysics Data System (ADS)

In a previous meeting, we described a computational approach to MRI morphometry, in which a spatial warp mapping a reference or atlas image into anatomic alignment with the subject is first inferred. Shape differences with respect to the atlas are then studied by calculating the pointwise Jacobian determinant for the warp, which provides a measure of the change in differential volume about a point in the reference as it transforms to its corresponding position in the subject. In this paper, the method is used to analyze sex differences in the shape and size of the corpus callosum in an ongoing study of a large population of normal controls. The preliminary results of the current analysis support findings in the literature that have observed the splenium to be larger in females than in males.

Gee, James C.; Fabella, Brian A.; Fernandes, Siddharth E.; Turetsky, Bruce I.; Gur, Ruben C.; Gur, Raquel E.

1999-05-01

159

Numerical Simulation of Micronozzles with Comparison to Experimental Results  

NASA Astrophysics Data System (ADS)

A numerical analysis of conical micronozzle flows has been conducted using the commercial software package CFD-RC FASTRAN [13]. The numerical results have been validated by comparison with direct thrust and mass flow measurements recently performed in ESTEC Propulsion Laboratory on Polyflex Space Ltd. 10mN Cold-Gas thrusters in the frame of ESA CryoSat mission. The flow is viscous dominated, with a throat Reynolds number of 5000, and the relatively large length of the nozzle causes boundary layer effects larger than usual for nozzles of this size. This paper discusses in detail the flow physics such as boundary layer growth and structure, and the effects of rarefaction. Furthermore a number of different domain sizes and exit boundary conditions are used to determine the optimum combination of computational time and accuracy.

Thornber, B.; Chesta, E.; Gloth, O.; Brandt, R.; Schwane, R.; Perigo, D.; Smith, P.

2004-10-01

160

Longitudinal variation of the equatorial ionosphere: Modeling and experimental results  

NASA Astrophysics Data System (ADS)

We describe a new version of the Parameterized Regional Ionospheric Model (PARIM) which has been modified to include the longitudinal dependences. This model has been reconstructed using multidimensional Fourier series. To validate PARIM results, the South America maps of critical frequencies for the E (foE) and F (foF2) regions were compared with the values calculated by Sheffield Plasmasphere-Ionosphere Model (SUPIM) and IRI representations. PARIM presents very good results, the general characteristics of both regions, mainly the presence of the equatorial ionization anomaly, were well reproduced for equinoctial conditions of solar minimum and maximum. The values of foF2 and hmF2 recorded over Jicamarca (12°S; 77°W; dip lat. 1°N; mag. declination 0.3°) and sites of the conjugate point equatorial experiment (COPEX) campaign Boa Vista (2.8°N; 60.7°W; dip lat. 11.4°; mag. declination -13.1°), Cachimbo (9.5°S; 54.8°W; dip lat. -1.8°; mag. declination -15.5°), and Campo Grande (20.4°S; 54.6°W; dip lat. -11.1°; mag. declination -14.0°) have been used in this work. foF2 calculated by PARIM show good agreement with the observations, except during morning over Boa Vista and midnight-morning over Campo Grande. Some discrepancies were also found for the F-region peak height (hmF2) near the geomagnetic equator during times of F3 layer occurrences. IRI has underestimated both foF2 and hmF2 over equatorial and low latitude sectors during evening-nighttimes, except for Jicamarca where foF2 values were overestimated.

Souza, J. R.; Asevedo, W. D.; dos Santos, P. C. P.; Petry, A.; Bailey, G. J.; Batista, I. S.; Abdu, M. A.

2013-02-01

161

Impact ejecta dynamics in an atmosphere - Experimental results and extrapolations  

NASA Technical Reports Server (NTRS)

It is noted that the impacts of 0.635-cm aluminum projectiles at 6 km/sec into fine pumice dust, at 1 atm, generate a ball of ionized gas behind an expanding curtain of upward moving ejecta. The gas ball forms a toroid which dissolves as it is driven along the interior of the ejecta curtain, by contrast to near-surface explosions in which a fireball envelops early-time crater growth. High frame rate Schlieren photographs show that the atmosphere at the base of the ejecta curtain is initially turbulent, but later forms a vortex. These experiments suggest that although small size ejecta may be decelerated by air drag, they are not simply lofted and suspended but become incorporated in an ejecta cloud that is controlled by air flow which is produced by the response of the atmosphere to the impact. The extrapolation of these results to large body impacts on the earth suggests such contrasts with laboratory experiments as a large quantity of impact-generated vapor, the supersonic advance of the ejecta curtain, the lessened effect of air drag due to the tenuous upper atmosphere, and the role of secondary cratering.

Schultz, P. H.; Gault, D. E.

1982-01-01

162

Bridge Testing With Ground-Based Interferometric Radar: Experimental Results  

NASA Astrophysics Data System (ADS)

The research of innovative non-contact techniques aimed at the vibration measurement of civil engineering structures (also for damage detection and structural health monitoring) is continuously directed to the optimization of measures and methods. Ground-Based Radar Interferometry (GBRI) represents the more recent technique available for static and dynamic control of structures and ground movements. Dynamic testing of bridges and buildings in operational conditions are currently performed: (a) to assess the conformity of the structure to the project design at the end of construction; (b) to identify the modal parameters (i.e. natural frequencies, mode shapes and damping ratios) and to check the variation of any modal parameters over the years; (c) to evaluate the amplitude of the structural response to special load conditions (i.e. strong winds, earthquakes, heavy railway or roadway loads). If such tests are carried out by using a non-contact technique (like GBRI), the classical issues of contact sensors (like accelerometers) are easily overtaken. This paper presents and discusses the results of various tests carried out on full-scale bridges by using a Stepped Frequency-Continuous Wave radar system.

Chiara, P.; Morelli, A.

2010-05-01

163

Experimental aflatoxicosis in swine: morphological and clinical pathological results.  

PubMed Central

The morphological changes in livers of 30 feeder pigs fed diets containing corn contaminated by aflatoxins (0.0 microgram aflatoxins/g feed, 0.4 microgram aflatoxin/g feed, and 0.8 microgram aflatoxin/g feed) were compared with changes in hematology, liver specific serum enzymes, serum proteins, and lymphocyte stimulation indices. Histologically, the livers were classified into five groups. Pigs fed the 0.8 microgram/g diets had the most severe histological lesions of karyomegaly, bile ductule proliferation and hepatocellular degeneration plus elevated gamma-glutamyl transpeptidase, aspartate aminotransferase, and alkaline phosphatase. This group also had significantly lower total protein and albumin values compared to the control pigs. Variation in the severity of the histological lesions was seen in pigs fed 0.4 microgram/g diets as well as variation in lymphocyte indices, liver specific serum enzymes, and electrophoretic results in the affected pigs in that group. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. PMID:7337866

Miller, D M; Stuart, B P; Crowell, W A

1981-01-01

164

Experimental results of the investigation of a laboratory cold seal TEC  

SciTech Connect

The results of experimental investigation of characteristics of a laboratory Cold Seal Thermionic Energy Converter (CS TEC) with a built-in gas regulated heat pipe are discussed. They were obtained to justify the electric-thermal-physical characteristics of a flame heated CS TEC. The CS TEC design is being developed by a joint Russian-Dutch team of researchers with support of the Netherlands Organization for Scientific Research (NWO). The concept of this flame heated Cold Seal TEC was presented in a previous publication. This paper deals with experimental data on the emission properties of electrodes and the voltage-current characteristics (JVC) of an electrically heated laboratory TEC. They were studied over a wide interval of variation in the electrode temperature and interelectrode distance. The cesium vapour working pressure in the interelectrode space was regulated both by the conventional method (using a cesium reservoir) and by means of a gas regulated cesium heat pipe. This allows one to use a rubber (viton) seal in the non-condensing gas (argon) area. The acquired experimental characteristics will allow one to identify the inner parameters at further stages of their work when testing the full-scale flame heated CS TEC.

Yarygin, V.I.; Mironov, V.S.; Kiryushenko, A.I.; Mikheyev, A.S.; Tulin, S.M.; Meleta, Y.A.; Yarygin, D.V.; Wolff, L.R.

1998-07-01

165

Dynamic soil-structure interaction-comparison of FEM model with experimental results  

E-print Network

to represent twenty different laboratory experiments. The results of these models are compared with results available from extensive experimental dynamic testing on a geotechnical centrifuge. Though the various results from the finite element analysis...

Srinivasan, Palanivel Rajan

2000-01-01

166

Femtosecond laser for glaucoma treatment: the comparison between simulation and experimentation results on ocular tissue removal  

NASA Astrophysics Data System (ADS)

In ophthalmology, the use of femtosecond lasers is receiving more attention than ever due to its extremely high intensity and ultra short pulse duration. It opens the highly beneficial possibilities for minimized side effects during surgery process, and one of the specific areas is laser surgery in glaucoma treatment. However, the sophisticated femtosecond laser-ocular tissue interaction mechanism hampers the clinical application of femtosecond laser to treat glaucoma. The potential contribution in this work lies in the fact, that this is the first time a modified moving breakdown theory is applied, which is appropriate for femtosecond time scale, to analyze femtosecond laser-ocular tissue interaction mechanism. Based on this theory, energy deposition and corresponding thermal increase are studied by both simulation and experimentation. A simulation model was developed using Matlab software, and the simulation result was validated through in-vitro laser-tissue interaction experiment using pig iris. By comparing the theoretical and experimental results, it is shown that femtosecond laser can obtain determined ocular tissue removal, and the thermal damage is evidently reduced. This result provides a promising potential for femtosecond laser in glaucoma treatment.

Hou, Dong Xia; Ngoi, Bryan K. A.; Hoh, Sek Tien; Koh, Lee Huat K.; Deng, Yuan Zi

2005-04-01

167

arXiv:astro-ph/0508014v131Jul2005 A review of experimental results at the knee1  

E-print Network

arXiv:astro-ph/0508014v131Jul2005 A review of experimental results at the knee1 J¨org R. H region of the knee are summarized. The all-particle energy spectrum, the mean logarithmic mass of about 4 PeV, the so called knee. In the literature various reasons for the origin of the knee

168

The coefficient of restitution of ice particles in glancing collisions: Experimental results for unfrosted surfaces  

NASA Technical Reports Server (NTRS)

Both Saturn's rings and planetesimal disks are made up of particles in Keplerian orbits. Inelastic collisions between these particles regulate their dynamical evolution and possible aggregation. We present an experiment to simulate glancing collisions in Saturn's rings and in planetesimal disks and thus measure contributions to the energy loss for both normal and tangential velocity components. In this experiment, a spherical iceball mounted on a long-period, two dimensional pendulum is made to impact a flat ice surface in a low-temperature environment. This paper describes the experimental apparatus in detail and presents results for smooth unfrosted surfaces. The energy loss for tangential motion is suprisingly low, indicating that very little friction is present at low impact speeds for relatively smooth ice surfaces and temperatures near 100 K. We have also investigated room-temperature collisions of a rubber ball on a rough surface to understand the energy loss in situations where the tangential friction force is not small. In this analogous case, the energy loss is maximum for impact angles in the range 45 deg-60 deg.

Supulver, Kimberley D.; Bridges, Frank G.; Lin, D. N. C.

1995-01-01

169

Molecular modeling of hair keratin/peptide complex: Using MM-PBSA calculations to describe experimental binding results.  

PubMed

Molecular dynamics simulations of a keratin/peptide complex have been conducted to predict the binding affinity of four different peptides toward human hair. Free energy calculations on the peptides' interaction with the keratin model demonstrated that electrostatic interactions are believed to be the main driving force stabilizing the complex. The molecular mechanics-Poisson-Boltzmann surface area methodology used for the free energy calculations demonstrated that the dielectric constant in the protein's interior plays a major role in the free energy calculations, and the only way to obtain accordance between the free energy calculations and the experimental binding results was to use the average dielectric constant. PMID:22275089

Azoia, Nuno G; Fernandes, Margarida M; Micaêlo, Nuno M; Soares, Cláudio M; Cavaco-Paulo, Artur

2012-05-01

170

Experimental results of two stage harmonic generation with picosecond pulses on the Stanford Mark III FEL  

NASA Astrophysics Data System (ADS)

We report experimental results on upper harmonic conversion using a lithium niobate and a beta barium borate crystal to quadruple the FEL light up into the visible and near infrared. The effects of finite linewidth, birefingent walk-off, and group velocity walk-off on conversion efficiency will be discussed with reference to the experimental results.

Hooper, Brett A.; Benson, Stephen V.; Cutolo, Antonello; Madey, John M. J.

1988-10-01

171

Experimental results of two stage harmonic generation with picosecond pulses on the Stanford Mark III FEL  

Microsoft Academic Search

We report experimental results on upper harmonic conversion using a lithium niobate and a beta barium borate crystal to quadruple the FEL light up into the visible and near infrared. The effects of finite linewidth, birefingent walk-off, and group velocity walk-off on conversion efficiency will be discussed with reference to the experimental results.

Brett A. Hooper; Stephen V. Benson; Antonello Cutolo; John M. J. Madey

1988-01-01

172

Macrokinetics of Mechanosynthesis in Solid-Gas Systems. II. Experimental Studies. Analysis of Results  

Microsoft Academic Search

Results from experimental studies of the nonisothermal mechanochemical reaction in the titanium-nitrogen system. Experimental data are compared with simulation results. The effective kinetic parameters of mechanical activation of the reactant and the chemical reaction are determined from analytical relations. It is shown that the developed mathematical model is suitable for the analysis of the macrokinetics of nonisothermal chemical reactions in

V. K. Smolyakov; V. I. Itin; N. N. Golobokov; N. G. Kasatskii; O. V. Lapshin; Yu. M. Maksimov; O. G. Terekhova; O. A. Shkoda

2005-01-01

173

VX hydrolysis by human serum paraoxonase 1: a comparison of experimental and computational results.  

PubMed

Human Serum paraoxonase 1 (HuPON1) is an enzyme that has been shown to hydrolyze a variety of chemicals including the nerve agent VX. While wildtype HuPON1 does not exhibit sufficient activity against VX to be used as an in vivo countermeasure, it has been suggested that increasing HuPON1's organophosphorous hydrolase activity by one or two orders of magnitude would make the enzyme suitable for this purpose. The binding interaction between HuPON1 and VX has recently been modeled, but the mechanism for VX hydrolysis is still unknown. In this study, we created a transition state model for VX hydrolysis (VX(ts)) in water using quantum mechanical/molecular mechanical simulations, and docked the transition state model to 22 experimentally characterized HuPON1 variants using AutoDock Vina. The HuPON1-VX(ts) complexes were grouped by reaction mechanism using a novel clustering procedure. The average Vina interaction energies for different clusters were compared to the experimentally determined activities of HuPON1 variants to determine which computational procedures best predict how well HuPON1 variants will hydrolyze VX. The analysis showed that only conformations which have the attacking hydroxyl group of VX(ts) coordinated by the sidechain oxygen of D269 have a significant correlation with experimental results. The results from this study can be used for further characterization of how HuPON1 hydrolyzes VX and design of HuPON1 variants with increased activity against VX. PMID:21655255

Peterson, Matthew W; Fairchild, Steven Z; Otto, Tamara C; Mohtashemi, Mojdeh; Cerasoli, Douglas M; Chang, Wenling E

2011-01-01

174

An Experimental and Theoretical High Energy Physics Program  

SciTech Connect

The Purdue High Energy Physics Group conducts research in experimental and theoretical elementary particle physics and experimental high energy astrophysics. Our goals, which we share with high energy physics colleagues around the world, are to understand at the most fundamental level the nature of matter, energy, space and time, and in order to explain the birth, evolution and fate of the Universe. The experiments in which we are currently involved are: CDF, CLEO-c, CMS, LSST, and VERITAS. We have been instrumental in establishing two major in-house facilities: The Purdue Particle Physics Microstructure Detector Facility (P3MD) in 1995 and the CMS Tier-2 center in 2005. The research efforts of the theory group span phenomenological and theoretical aspects of the Standard Model as well as many of its possible extensions. Recent work includes phenomenological consequences of supersymmetric models, string theory and applications of gauge/gravity duality, the cosmological implications of massive gravitons, and the physics of extra dimensions.

Shipsey, Ian

2012-07-31

175

Experimental And Theoretical High Energy Physics Research At UCLA  

SciTech Connect

This is the final report of the UCLA High Energy Physics DOE Grant No. DE-FG02- 91ER40662. This report covers the last grant project period, namely the three years beginning January 15, 2010, plus extensions through April 30, 2013. The report describes the broad range of our experimental research spanning direct dark matter detection searches using both liquid xenon (XENON) and liquid argon (DARKSIDE); present (ICARUS) and R&D for future (LBNE) neutrino physics; ultra-high-energy neutrino and cosmic ray detection (ANITA); and the highest-energy accelerator-based physics with the CMS experiment and CERN’s Large Hadron Collider. For our theory group, the report describes frontier activities including particle astrophysics and cosmology; neutrino physics; LHC interaction cross section calculations now feasible due to breakthroughs in theoretical techniques; and advances in the formal theory of supergravity.

Cousins, Robert D. [University of California Los Angeles] [University of California Los Angeles

2013-07-22

176

TRIDENT high-energy-density facility experimental capabilities and diagnostics  

SciTech Connect

The newly upgraded TRIDENT high-energy-density (HED) facility provides high-energy short-pulse laser-matter interactions with powers in excess of 200 TW and energies greater than 120 J. In addition, TRIDENT retains two long-pulse (nanoseconds to microseconds) beams that are available for simultaneous use in either the same experiment or a separate one. The facility's flexibility is enhanced by the presence of two separate target chambers with a third undergoing commissioning. This capability allows the experimental configuration to be optimized by choosing the chamber with the most advantageous geometry and features. The TRIDENT facility also provides a wide range of standard instruments including optical, x-ray, and particle diagnostics. In addition, one chamber has a 10 in. manipulator allowing OMEGA and National Ignition Facility (NIF) diagnostics to be prototyped and calibrated.

Batha, S. H.; Aragonez, R.; Archuleta, F. L.; Archuleta, T. N.; Benage, J. F.; Cobble, J. A.; Cowan, J. S.; Fatherley, V. E.; Flippo, K. A.; Gautier, D. C.; Gonzales, R. P.; Greenfield, S. R.; Hegelich, B. M.; Hurry, T. R.; Johnson, R. P.; Kline, J. L.; Letzring, S. A.; Loomis, E. N.; Lopez, F. E.; Luo, S. N. [Los Alamos National Laboratory, P.O. Box 1663, MS E526, Los Alamos, New Mexico 87545 (United States)] (and others)

2008-10-15

177

Experimental energy loss of slow H+ and H+2 in channeling conditions  

NASA Astrophysics Data System (ADS)

The interactions of hydrogen molecular ions (H+2) and protons in the low energy range (E<7.5 keV/u) with very thin foils of monocrystalline gold are experimentally studied. Measurements of energy loss distributions of molecular fragments, recombined molecules, and protons channeled in the <100> direction of a monocrystalline gold thin film have been performed. From the energy loss data we determine the stopping power ratio, which shows a significant negative “vicinage effect,” giving a reduced energy loss of molecular fragments and recombined molecules as compared to the energy loss of protons. This effect is more pronounced in the case of detected molecules. Computational simulations, where nonlinear models are included, qualitatively agree with our experimental results and suggest that some pairs of ions travel and emerge from the crystal with appropriate internuclear distances and relative velocities and are able to recombine at the exit.

Valdés, J. E.; Parra, C.; Díaz-Valdés, J.; Denton, C. D.; Agurto, C.; Ortega, F.; Arista, N. R.; Vargas, P.

2003-12-01

178

Experimental demonstration of thermoacoustic energy conversion in a resonator  

Microsoft Academic Search

Using thermoacoustic energy conversions, both amplification and damping of acoustic intensity are demonstrated. A differentially heated regenerator is installed near the velocity node of the resonator and thereby a high specific acoustic impedance and a traveling wave phase are obtained. It is shown that the gain of acoustic intensity resulting from the traveling wave energy conversion reaches 1.7 in a

Tetsushi Biwa; Yusuke Tashiro; Uichiro Mizutani; Motoki Kozuka; Taichi Yazaki

2004-01-01

179

Experimental and computational surface and flow-field results for an all-body hypersonic aircraft  

NASA Technical Reports Server (NTRS)

The objective of the present investigation is to establish a benchmark experimental data base for a generic hypersonic vehicle shape for validation and/or calibration of advanced computational fluid dynamics computer codes. This paper includes results from the comprehensive test program conducted in the NASA/Ames 3.5-foot Hypersonic Wind Tunnel for a generic all-body hypersonic aircraft model. Experimental and computational results on flow visualization, surface pressures, surface convective heat transfer, and pitot-pressure flow-field surveys are presented. Comparisons of the experimental results with computational results from an upwind parabolized Navier-Stokes code developed at Ames demonstrate the capabilities of this code.

Lockman, William K.; Lawrence, Scott L.; Cleary, Joseph W.

1990-01-01

180

Experimental Validation of a Novel Compact Focusing Scheme for Future Energy-Frontier Linear Lepton Colliders  

NASA Astrophysics Data System (ADS)

A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed in 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This scheme has many advantageous properties over previously studied focusing schemes, including being significantly shorter for a given energy and having a significantly better energy bandwidth. Experimental results from the ATF2 accelerator at KEK are presented that validate the operating principle of such a scheme by demonstrating the demagnification of a 1.3 GeV electron beam down to below 65 nm in height using an energy-scaled version of the compact focusing optics designed for the ILC collider.

White, G. R.; Ainsworth, R.; Akagi, T.; Alabau-Gonzalvo, J.; Angal-Kalinin, D.; Araki, S.; Aryshev, A.; Bai, S.; Bambade, P.; Bett, D. R.; Blair, G.; Blanch, C.; Blanco, O.; Blaskovic-Kraljevic, N.; Bolzon, B.; Boogert, S.; Burrows, P. N.; Christian, G.; Corner, L.; Davis, M. R.; Faus-Golfe, A.; Fukuda, M.; Gao, J.; García-Morales, H.; Geffroy, N.; Hayano, H.; Heo, A. Y.; Hildreth, M.; Honda, Y.; Huang, J. Y.; Hwang, W. H.; Iwashita, Y.; Jang, S.; Jeremie, A.; Kamiya, Y.; Karataev, P.; Kim, E. S.; Kim, H. S.; Kim, S. H.; Kim, Y. I.; Komamiya, S.; Kubo, K.; Kume, T.; Kuroda, S.; Lam, B.; Lekomtsev, K.; Liu, S.; Lyapin, A.; Marin, E.; Masuzawa, M.; McCormick, D.; Naito, T.; Nelson, J.; Nevay, L. J.; Okugi, T.; Omori, T.; Oroku, M.; Park, H.; Park, Y. J.; Perry, C.; Pfingstner, J.; Phinney, N.; Rawankar, A.; Renier, Y.; Resta-López, J.; Ross, M.; Sanuki, T.; Schulte, D.; Seryi, A.; Shevelev, M.; Shimizu, H.; Snuverink, J.; Spencer, C.; Suehara, T.; Sugahara, R.; Takahashi, T.; Tanaka, R.; Tauchi, T.; Terunuma, N.; Tomás, R.; Urakawa, J.; Wang, D.; Warden, M.; Wendt, M.; Wolski, A.; Woodley, M.; Yamaguchi, Y.; Yamanaka, T.; Yan, J.; Yokoya, K.; Zimmermann, F.; ATF2 Collaboration

2014-01-01

181

Comparison between Theoretical Calculation and Experimental Results of Excitation Functions for Production of Relevant Biomedical Radionuclides  

NASA Astrophysics Data System (ADS)

The radionuclide production for biomedical applications has been brought up in the years, as a special nuclear application, at INFN LASA Laboratory, particularly in co-operation with the JRC-Ispra of EC. Mainly scientific aspects concerning radiation detection and the relevant instruments, the measurements of excitation functions of the involved nuclear reactions, the requested radiochemistry studies and further applications have been investigated. On the side of the nuclear data evaluations, based on nuclear model calculations and critically selected experimental data, the appropriate competence has been developed at ENEA Division for Advanced Physics Technologies. A series of high specific activity accelerator-produced radionuclides in no-carrier-added (NCA) form, for uses in metabolic radiotherapy and for PET radiodiagnostics, are investigated. In this work, last revised measurements and model calculations are reviewed for excitation functions of natZn(d,X)64Cu, 66Ga reactions, referring to irradiation experiments at K=38 variable energy Cyclotron of JRC-Ispra. Concerning the reaction data for producing 186gRe and 211At/211gPo (including significant emission spectra) and 210At, most recent and critically selected experimental results are considered and discussed in comparison with model calculations paying special care to pre-equilibrium effects estimate and to the appropriate overall parameterization. Model calculations are presented for 226Ra(p,2n)225Ac reaction, according to the working program of the ongoing IAEA CRP on the matter.

Menapace, E.; Birattari, C.; Bonardi, M. L.; Groppi, F.; Morzenti, S.; Zona, C.

2005-05-01

182

A comparison of experimental and theoretical results for labyrinth gas seals with honeycomb stators  

E-print Network

) Lawrence Allen Hawkins, B. S. , Auburn University; Chair of Advisory Committee: Dr. Dara Childs Experimental results for the rotordynamic stiffness and damping coefficients of a labyrinth-rotor/honeycomb-stator seal are presented. The coefficients... are compared to the coefficients of a labyrinth-rotor/smooth-stator seal having the same geometry. The coefficients are also compared to analytical results from a two-control-volume compressible ffow model. The experimental results show that the honeycomb...

Hawkins, Lawrence Allen

1988-01-01

183

Comparative studies on shielding properties of some steel alloys using Geant4, MCNP, WinXCOM and experimental results  

NASA Astrophysics Data System (ADS)

The mass attenuation coefficients, ?/? and effective atomic numbers, Zeff of some carbon steel and stainless steel alloys have been calculated by using Geant4, MCNP simulation codes for different gamma ray energies, 279.1 keV, 661.6 keV, 662 keV, 1115.5 keV, 1173 keV and 1332 keV. The simulation results of Zeff using Geant4 and MCNP codes have been compared with possible available experimental results and theoretical WinXcom, and good agreement has been observed. The simulated ?/? and Zeff values using Geant4 and MCNP code signifies that both the simulation process can be followed to determine the gamma ray interaction properties of the alloys for energies wherever analogous experimental results may not be available. This kind of studies can be used for various applications such as for radiation dosimetry, medical and radiation shielding.

Singh, Vishwanath P.; Medhat, M. E.; Shirmardi, S. P.

2015-01-01

184

Determination of the vertical electron-density prole in ionospheric tomography: experimental results  

E-print Network

presented by Pryse et al. (1995) show travelling ionospheric disturbances in consecutive tomographic images demonstrated the tomographic imaging of travelling ionospheric disturbances. Experimental results from RussiaDetermination of the vertical electron-density pro®le in ionospheric tomography: experimental

Paris-Sud XI, Université de

185

An analysis of experimental results on fluctuations of muon and electron numbers in extensive air showers  

Microsoft Academic Search

The theoretical results derived in the previous paper by de Beer et al. in 1968 have been compared with experimental observations, with reference to the fluctuations in the total numbers of muons and electrons and to the variation of the mean number of muons with shower size.It is found that the derivation of accurate parameters from experimental data is very

C. Adcock; J. F. de Beer; H. Oda; J. Wdowczyk; A. W. Wolfendale

1968-01-01

186

Measurement of uranium enrichment by gamma spectroscopy: result of an experimental design  

E-print Network

PAPER Measurement of uranium enrichment by gamma spectroscopy: result of an experimental design Gamma spectroscopy is commonly used in nuclear safeguards to measure uranium enrichment. An experimental design has been carried out for the measurement of uranium enrichment using this technique with different

187

Output regulation for nonlinear systems: some recent theoretical and experimental results  

Microsoft Academic Search

This brief summarizes recent theoretical and presents experimental results of output regulation for nonlinear systems. The main contribution of this brief consists of the first experimental study of output regulation using a two-link underactuated mechanical system-the Pendubot.

Tzyh-Jong Tarn; P. Sanposh; Daizhan Cheng; Mingjun Zhang

2005-01-01

188

Experimental reconstruction of excitation energies of primary hot isotopes in heavy ion collisions near the Fermi energy  

NASA Astrophysics Data System (ADS)

The excitation energies of the primary hot isotopes in multifragmentation events are experimentally reconstructed in the reaction system 64Zn + 112Sn at 40 MeV/nucleon. A kinematical focusing method is employed to evaluate the multiplicities of the evaporated light particles associated with isotopically identified fragments with 3?Z?14. Angular distributions of the velocity spectra of light charged particles and neutrons associated with trigger isotopes are examined. A moving source fit is used to separate the kinematically correlated particles, evaporated from the parents of the detected isotopes, from the uncorrelated particles originating from other sources. The latter are evaluated experimentally relative to those in coincidence with the Li isotopes. A parameter, k, is used to adjust the yield of the uncorrelated particles for different trigger isotopes. For each experimentally detected isotope, the multiplicities, apparent temperatures, and k values for n, p, d, t, and ? particles are extracted. Using the extracted values, the excitation energies of the primary hot isotopes are reconstructed employing a Monte Carlo method. The extracted excitation energies are in the range of 1 to 4 MeV/nucleon but show a significant decreasing trend as a function of A for a given Z of the isotopes. The results are compared with those of antisymmetrized molecular dynamics (AMD) and statistical multifragmentation model (SMM) simulations. While some of the experimental characteristics are predicted partially by each model, neither simulation reproduces the overall characteristics of the experimental results.

Rodrigues, M. R. D.; Lin, W.; Liu, X.; Huang, M.; Zhang, S.; Chen, Z.; Wang, J.; Wada, R.; Kowalski, S.; Keutgen, T.; Hagel, K.; Barbui, M.; Bottosso, C.; Bonasera, A.; Natowitz, J. B.; Materna, T.; Qin, L.; Sahu, P. K.; Schmidt, K. J.

2013-09-01

189

Experimental studies of pion-nucleus interactions at intermediate energies  

SciTech Connect

This report summarizes the work on experimental research in intermediate energy nuclear physics carried out at New Mexico State University in 1991 under a great from the US Department of Energy. Most of these studies have involved investigations of various pion-nucleus interactions. The work has been carried out both with the LAMPF accelerator at the Los Alamos National Laboratory and with the cyclotron at the Paul Scherrer Institute (PSI) near Zurich, Switzerland. Part of the experimental work involves measurements of new data on double-charge-exchange scattering, using facilities at LAMPF which we helped modify, and on pion absorption, using a new detector system at PSI that covers nearly the full solid-angle region which we helped construct. Other work involved preparation for future experiments using polarized nuclear targets and a new high-resolution spectrometer system for detecting {pi}{sup 0} mesons. We also presented several proposals for works to be done in future years, involving studies related to pi-mesonic atoms, fundamental pion-nucleon interactions, studies of the difference between charged and neutral pion interactions with the nucleon, studies of the isospin structure of pion-nucleus interactions, and pion scattering from polarized {sup 3}He targets. This work is aimed at improving our understanding of the pion-nucleon interaction, of the pion-nucleus interaction mechanism, and of nuclear structure.

Not Available

1991-12-31

190

Theoretical and experimental study of energy loss of Li ions in Zn  

NASA Astrophysics Data System (ADS)

We have performed a combined theoretical and experimental study of the energy loss of Li ions in Zn, on a wide range of energies, together with comparative studies for H and He ions on the same target. By using Zn films and the Rutherford backscattering technique, we were able to determine the stopping power for Li ions in the (0.3 to 5) MeV energy interval. The experimental results cover an energy range which includes the maximum of the stopping power. The values obtained agree well with previous measurements performed in a limited energy interval and with the semiempirical code SRIM 2006. On the other hand, we have performed ab initio theoretical calculations based on the extended Friedel sum rule-transport cross section formulation for the valence electrons and the shellwise local plasma approximation for the inner shells. This theoretical description reproduces reasonably well the experimental results on the whole studied energy range. The same occurs with previous measurements performed with H and He on the same target. The importance of the screened potential on the stopping power due to the valence electrons is stressed in the present description.

Montanari, C. C.; Miraglia, J. E.; Behar, M.; Duarte, P. F.; Arista, N. R.; Eckardt, J. C.; Lantschner, G. H.

2008-04-01

191

Experimental and theoretical study of the energy loss of C and O in Zn  

NASA Astrophysics Data System (ADS)

We present a combined experimental-theoretical study of the energy loss of C and O ions in Zn in the energy range 50-1000 keV/amu. This contribution has a double purpose, experimental and theoretical. On the experimental side, we present stopping power measurements that fill a gap in the literature for these projectile-target combinations and cover an extended energy range, including the stopping maximum. On the theoretical side, we make a quantitative test on the applicability of various theoretical approaches to calculate the energy loss of heavy swift ions in solids. The description is performed using different models for valence and inner-shell electrons: a nonperturbative scattering calculation based on the transport cross section formalism to describe the Zn valence electron contribution, and two different models for the inner-shell contribution: the shellwise local plasma approximation (SLPA) and the convolution approximation for swift particles (CasP). The experimental results indicate that C is the limit for the applicability of the SLPA approach, which previously was successfully applied to projectiles from H to B. We find that this model clearly overestimates the stopping data for O ions. The origin of these discrepancies is related to the perturbative approximation involved in the SLPA. This shortcoming has been solved by using the nonperturbative CasP results to describe the inner-shell contribution, which yields a very good agreement with the experiments for both C and O ions.

Cantero, E. D.; Montanari, C. C.; Behar, M.; Fadanelli, R. C.; Lantschner, G. H.; Miraglia, J. E.; Arista, N. R.

2011-07-01

192

Experimental results of beam brightness experiments at the Advanced Test Accelerator (ATA)  

SciTech Connect

Experimental data show improved brightness of Lawrence Livermore National Laboratory's Advanced Test Accelerator both at the injector and at the high-energy output. The effects of matching onto a laser-produced ion channel have been demonstrated, and an improved matching technique is now being used.

Weir, J.T.; Boyd, J.K.; Caporaso, G.J.; Orzechowski, T.J.

1987-03-01

193

Comparison of experimental coupled helicopter rotor/body stability results with a simple analytical model  

NASA Technical Reports Server (NTRS)

The results of an analytical study aimed at predicting the aeromechanical stability of a helicopter in ground resonance, with the inclusion of aerodynamic forces are presented. The theoretical results are found to be in good agreement with the experimental results, available in literature, indicating that the coupled rotor/fuselage system can be represented by a reasonably simple mathematical model.

Friedmann, P. P.; Venkatesan, C.

1988-01-01

194

Experimental Results for Temporally Overlapping Pulses from Quantel EverGreen 200 Laser  

NASA Technical Reports Server (NTRS)

This report will detail the experimental results and observations obtained while investigating the feasibility of temporally overlapping the two laser pulses from a Quantel EverGreen 200 Laser. This laser was specifically designed for Particle Imaging Velocimetry (PIV) applications and operate by emitting two 532 nm laser pulses that are seperated by an adjustable finite time (typically on the order of ten to hundreds of microseconds). However, the use of this model laser has found recent application for Pressure Sensitive Paint (PSP) testing, especially for rotorcraft research. For this testing, it is desired to only use one laser pulse. While this is easily done by only firing one of the laser heads, more excitation energy could conceivably be had if both laser heads are fired with zero pulse separation. In addition, recently large field-of-view PIV measurements have become possible and need ever increasing laser power to illuminate the larger areas. For this work, two different methods of timing the laser are investigated using both a traditional power meter to monitor laser power as well as a fast photodiode to determine pulse separation. The results are presented here as well as some simple implications for PIV experiments using these methods.

Watkins, A. Neal

2013-01-01

195

Energy Monitoring--Objectives vs Results  

E-print Network

~L~O~e~A~T~I~O~N~----~?Best Guess? IrT~RA~N~sSiD"uiRegI.e I DATA ACO. I Computer l !I.... The technology that exists today meets the most stringent requirements for energy monitoring systems. Flow transducers, remote processing units and central processing software designed specifically for energy monitoring are providing accurate informatio...

McEver, R. M. Jr.

196

Energy Monitoring in Gins - 2012 Preliminary Results  

Technology Transfer Automated Retrieval System (TEKTRAN)

Electricity and fuel are the second largest source of variable costs for cotton gins, after labor. Few studies of gin energy use have been conducted recently and none have monitored energy use continuously throughout the ginning season. More detailed information is needed to identify management st...

197

Inter-species extrapolation of skin heating resulting from millimeter wave irradiation: modeling and experimental results.  

PubMed

This study reports measurements of the skin surface temperature elevations during localized irradiation (94 GHz) of three species: rat (irradiated on lower abdomen), rhesus monkey (posterior forelimb), and human (posterior forearm). Two exposure conditions were examined: prolonged, low power density microwaves (LPM) and short-term, high power density microwaves (HPM). Temperature histories were compared with calculations from a bio-heat transfer model. The mean peak surface temperature increase was approximately 7.0 degrees C for the short-term HPM exposures for all three species/locations, and 8.5 degrees C (monkey, human) to 10.5 degrees C (rat) for the longer-duration LPM exposures. The HPM temperature histories are in close agreement with a one-dimensional conduction heat transfer model with negligible blood flow. The LPM temperature histories were compared with calculations from the bio-heat model, evaluated for various (constant) blood flow rates. Results suggest a variable blood flow model, reflecting a dynamic thermoregulatory response, may be more suited to describing skin surface temperature response under long-duration MMW irradiation. PMID:12747480

Nelson, D A; Walters, T J; Ryan, K L; Emerton, K B; Hurt, W D; Ziriax, J M; Johnson, L R; Mason, P A

2003-05-01

198

Experimental High Energy Physics Brandeis University Final Report  

SciTech Connect

During the past three years, the Brandeis experimental particle physics group was comprised of four faculty (Bensinger, Blocker, Sciolla, and Wellenstein), one research scientist, one post doc, and ten graduate students. The group focused on the ATLAS experiment at LHC. In 2011, the LHC delivered 5/fb of pp colliding beam data at a center-of-mass energy of 7 TeV. In 2012, the center-of-mass energy was increased to 8 TeV, and 20/fb were delivered. The Brandeis group focused on two aspects of the ATLAS experiment -- the muon detection system and physics analysis. Since data taking began at the LHC in 2009, our group actively worked on ATLAS physics analysis, with an emphasis on exploiting the new energy regime of the LHC to search for indications of physics beyond the Standard Model. The topics investigated were Z' -> ll, Higgs -> ZZ* -. 4l, lepton flavor violation, muon compositeness, left-right symmetric theories, and a search for Higgs -> ee. The Brandeis group has for many years been a leader in the endcap muon system, making important contributions to every aspect of its design and production. During the past three years, the group continued to work on commissioning the muon detector and alignment system, development of alignment software, and installation of remaining chambers.

Blocker, Craig A. [Brandeis University] [Brandeis University; Bensinger, James [Brandeis University] [Brandeis University; Sciolla, Gabriella [Brandeis University] [Brandeis University; Wellenstein, Hermann [Brandeis University] [Brandeis University

2013-07-26

199

Showing results, 3 Energy technology and energy planning  

E-print Network

loads, 6 ­ Energy materials and new energy technologies, 8 Fuel cells, 8 Superconductors, 8 Fusion progress of the fuel cell project deserves attention. The project which is managed by Risø is so far techniques for industry ­ Wind energy, 4 Wind turbines, 4 Wind energy systems, 5 Wind resources and wind

200

Selected problems in experimental intermediate energy physics. Progress report  

SciTech Connect

Objectives of this research program are to investigate forefront problems in experimental intermediate-energy physics, educate students in this field of research, and develop the instrumentation necessary. Generally, this research is designed to search for physical processes that cannot be explained by conventional models of elementary interactions. The program has three major thrusts: strange particle physics, where a strange quark is embedded in the nuclear medium; muon electro-weak decay, which involves a search for a violation of the standard model of the electro-weak interaction; and measurement of the spin-dependent structure function of the neutron. Current research is reported in the following areas: hyperon physics at the AGS, electroproduction of hypernuclei, test of the standard model of electro-weak interactions, spin structure function of nucleons, and instrumentation.

Mayes, B.W.; Hungerford, E.V.; Pinsky, L.S.

1992-09-01

201

Experimental Results on p(d)+A Collisions at RHIC and the LHC  

E-print Network

Recent experimental results at both the LHC and RHIC show evidence for hydrodynamic behavior in proton-nucleus and deuteron- nucleus collisions (p+A). This unexpected finding has prompted new measurements in p+A collisions in order to understand whether similar matter is created in A+A and p+A collisions or whether some another explanation is needed. In this proceedings, we will discuss the new experimental data and its interpretation within the context of heavy ion collisions.

Anne M. Sickles

2014-08-21

202

A stereo triangulation system for structural identification: Analytical and experimental results  

NASA Technical Reports Server (NTRS)

Identification of large space structures' distributed mass, stiffness, and energy dissipation characteristics poses formidable analytical, numerical, and implementation difficulties. Development of reliable on-orbit structural identification methods is important for implementing active vibration suppression concepts which are under widespread study in the large space structures community. Near the heart of the identification problem lies the necessity of making a large number of spatially distributed measurements of the structure's vibratory response and the associated force/moment inputs with sufficient spatial and frequency resolution. In the present paper, we discuss a method whereby tens of active or passive (retro-reflecting) targets on the structure are tracked simultaneously by the focal planes of two or more video cameras mounted on an adjacent platform. Triangulation (optical ray intersection) of the conjugate image centroids yield inertial trajectories of each target on the structure. Given the triangulated motion of the targets, we apply and extend methodology developed by Creamer, Junkins, and Juang to identify the frequencies, mode shapes, and updated estimates for the mass/stiffness/damping parameterization of the structure. The methodology is semi-automated, for example, the post experiment analysis of the video imagery to determine the inertial trajectories of the targets typically requires less than thirty minutes of real time. Using methodology discussed herein, the frequency response of a large number of points on the structure (where reflective targets are mounted) on the structure can be determined from optical measurements alone. For comparison purposes, we also utilize measurements from accelerometers and a calibrated impulse hammer. While our experimental work remains in a research stage of development, we have successfully tracked and stereo triangulated 20 targets (on a vibrating cantilevered grid structure) at a sample frequency of 200 HZ, and have established conclusively the feasibility and desirability of this approach. We discuss, in summary, recent advances in analog and digital video processing methodology, actuation methods, and bring them to bear on the structural identification problem. We include a brief discussion of our experimental hardware and some recent experimental results which support the practical feasibility of this structural vibration sensing approach.

Junkins, J. L.; James, G. H., III; Pollock, T. C.; Rahman, Z. H.

1988-01-01

203

Experimental limit on the cosmic diffuse ultrahigh energy neutrino flux.  

PubMed

We report results from 120 h of live time with the Goldstone lunar ultrahigh energy neutrino experiment (GLUE). The experiment searches for < or = 10 ns microwave pulses from the lunar regolith, appearing in coincidence at two large radio telescopes separated by 22 km and linked by optical fiber. Such pulses would arise from subsurface electromagnetic cascades induced by interactions of > or = 100 EeV (1 EeV = 10(18) eV neutrinos in the lunar regolith. No candidates are yet seen, and the implied limits constrain several current models for ultrahigh energy neutrino fluxes. PMID:15323748

Gorham, P W; Hebert, C L; Liewer, K M; Naudet, C J; Saltzberg, D; Williams, D

2004-07-23

204

Dynamic characterization of composites with embedded shape memory alloys: Some experimental results  

SciTech Connect

Composites with embedded Shape Memory Alloy (SMA) fibers are considered to be adaptive materials. The physical properties of these materials can be modified by applying certain stimuli through the fibers. These changes mainly concern stiffness and damping of the material and strongly modify the vibrational behavior of structures made of these materials. The design of smart structures incorporating adaptive materials, assumes precise knowledge of material as well as structure behavior. The paper explores two methods for obtaining a dynamic characterization of thin epoxy composites plates with embedded SMA fibers. The first method, experimental modal analysis, determines the modal parameters of the composite structure. The second method, based on natural frequency and modal damping ratio measurements, determines the complex engineering constants of the composite material. Results are obtained at room temperature for test plates with martensitic and austenitic (Cu/Zn/Al) fibers. Comparisons are made with respect to at est plate without fibers. Finally, a modal strain energy approach is used to numerically determine modal damping ratios of the test plates from the values of the complex engineering constants.

De Santis, S.; Trochu, F.; Ostiguy, G. [Ecole Polytechnique, Montreal, Quebec (Canada). Dept. de Genie Mecanique; Sol, H.; DeVisscher, J. [Univ. de Bruxelles (Belgium). Dept. d`Analyse Structurale

1995-10-01

205

Development, calibration, and experimental results obtained with an innovative calorimeter (CALMOS) for nuclear heating measurements  

SciTech Connect

Nuclear heating inside an MTR reactor has to be known in order to be able to control samples temperature during irradiation experiments. An R and D program has been carried out at CEA to design a new type of in-core calorimetric system. This new development, started in 2002, has for main objective to manufacture a calorimeter suitable to monitoring nuclear heating inside the 70 MWth OSIRIS material testing reactor operated by CEA's Nuclear Energy Division at the Saclay research center. An innovative calorimetric probe, associated to a specific handling system, has been designed to provide access to measurements both along the fissile height and on the upper part of the core, where nuclear heating still remains high. Two mock-ups of the probe were manufactured and tested in 2005 and 2009 in ex-core area of OSIRIS reactor for process validation, while a displacement system has been especially studied to move the probe along a given axial measurement range. This paper deals with the development, tests on preliminary mock-ups and the finalization of the probe. Main modeling and experimental results are presented. Moreover, alternative methods to calibration for nuclear heating rate measurements which are now possible with this new calorimeter are presented and discussed. (authors)

Carcreff, Hubert; Cloute-Cazalaa, Veronique; Salmon, Laurent [CEA, DEN, DRSN, SIREN, LASPI Saclay, F-91191 Gif Sur Yvette, (France)

2012-08-15

206

Development, calibration and experimental results obtained with an innovative calorimeter (CALMOS) for nuclear heating measurements  

SciTech Connect

Nuclear heating inside an MTR reactor has to be known in order to be able to control samples temperature during irradiation experiments. An R and D program has been carried out at CEA to design a new type of in-core calorimetric system. This new development, started in 2002, has for main objective to manufacture a calorimeter suitable to monitoring nuclear heating inside the 70 MWth OSIRIS material testing reactor operated by CEA's Nuclear Energy Div. at the Saclay research center. An innovative calorimetric probe, associated to a specific handling system, has been designed to provide access to measurements both along the fissile height and on the upper part of the core, where nuclear heating still remains high. Two mock-ups of the probe were manufactured and tested in 2005 and 2009 in ex-core area of OSIRIS reactor for process validation, while a displacement system has been especially studied to move the probe along a given axial measurement range. This paper deals with the development, tests on preliminary mock-ups and the finalization of the probe. Main modeling and experimental results are presented. Moreover, alternative methods to calibration for nuclear heating rate measurements which are now possible with this new calorimeter are presented and discussed. (authors)

Carcreff, H.; Cloute-Cazalaa, V.; Salmon, L. [CEA/DEN/DRSN/SIREN/LASPI (Saclay), F-91191 Gif sur Yvette Cedex (France)

2011-07-01

207

Biaxial box plots and ordered trial ranks for visualizing large sets of experimental results  

Microsoft Academic Search

This paper presents a novel method for visualizing large experimental datasets called a Biaxial Box Plot which provides both an easily read general impression of the results that highlights performance trends whilst also allowing for careful comparison of individual results. The Biaxial Box Plot is compared against heatmaps and traditional box plots where it is argued that the new method

Kent McClymont

2012-01-01

208

New Results from High Energy Gamma-Ray Astronomy  

E-print Network

High energy gamma-ray astronomy has recently made significant progresss through ground-based instruments like the {\\it H.E.S.S.} array of imaging atmospheric Cherenkov telescopes. The unprecedented angular resolution and the large field of view has allowed to spatially resolve for the first time the morphology of gamma-ray sources in the TeV energy range. The experimental technique is described and the types of sources detected and still expected are discussed. Selected results include objects as different as a Galactic binary Pulsar, the Galactic Center and Supernova Remnants but they also concern the diffuse extragalactic optical/infrared radiation field. Finally, a scan of the Galactic plane in TeV gamma rays is described which has led to a significant number of new TeV sources, many of which are still unidentified in other wavelengths. The field has a close connection with X-ray astronomy which allows the study of the synchrotron emission from these very high energy sources.

Heinrich J. Voelk

2006-03-18

209

Energy resolution and absolute detection efficiency for LSO crystals: A comparison between Monte Carlo simulation and experimental data  

NASA Astrophysics Data System (ADS)

Non-proportionality between energy deposition and scintillation light production in a scintillator and transport of scintillation photons in the detector have been introduced in a Geant4-based simulation code. Simulation and experimental results were compared for samples of LSO detectors: absolute detector efficiency and energy resolution obtained from simulation are consistent with the experimental data. We also studied the average path length of scintillation photons in the detector and its contribution to the time resolution.

Rothfuss, Harold; Byars, Larry; Casey, Michael E.; Conti, Maurizio; Eriksson, Lars; Michel, Christian

2007-10-01

210

Experimental study on centrifugal pumps energy labelling in Iran  

NASA Astrophysics Data System (ADS)

The main goal of the present study was developing the energy label instruction for small centrifugal pumps. First the types of energy labels which are popular in the world especially three types of energy labels were introduced and discussed, two of which belongs to European United and the other one is assigned to Iran. Modified Iran labelling procedure with reasons was criticized and presented as a new approach in the present study. In the next step, e a standard test rig was established for testing of the small centrifugal pumps. A standard centrifugal pump named 32-160 and 32-200 was selected as the case studies. The selected pumps were test in the test rig and then labelled using selected methods. Finally the results considered and discoursed.

Derakhshan, S.; Abdolahnejad, E.; Buzari, M.

2012-11-01

211

Experimental and numerical investigation on damping properties and energy dissipation mechanisms of magnetosensitive rubber  

NASA Astrophysics Data System (ADS)

This study presents both numerical and experimental investigation on damping properties and energy dissipation mechanisms of magnetosensitive rubber (MSR). Representative volume element (RVE) including particles and matrix was built and periodic boundary condition (PBC) was applied. Various sinusoidal loads, with different frequencies, were applied to RVE under external magnetic field. Considering interaction and complex mechanisms in multi-physics field, finite element method (FEM) based on magneto-mechanical coupling algorithm was adopted. MSR samples were fabricated by aligning iron particles with millimeter level diameter in silicone rubber matrix. The correctness of the numerical method was verified by comparing the results of simulation and quasi-static load test. Dynamic experimental measurement was conducted in material test system. The results demonstrate that the damping properties of MSR are influenced by magnetic induction density and frequency of sinusoidal load. Energy dissipation mechanisms of MSR were explored.

Li, W.; Sun, L.; Sun, J.; Chen, W.; Ma, F.; Leng, D.

2013-02-01

212

Experimental High Energy Physics Research: Direct Detection of Dark Matter  

SciTech Connect

The grant supported research on an experimental search for evidence of dark matter interactions with normal matter. The PI carried out the research as a member of the LUX and LZ collaborations. The LUX research team collected a first data set with the LUX experiment, a large liquid xenon detector installed in the Sanford Underground Research Facility (SURF). The first results were published in Physical Review Letters on March 4, 2014. The journal Nature named the LUX result a scientific highlight of the year for 2013. In addition, the LZ collaboration submitted the full proposal for the Lux Zeplin experiment, which has since been approved by DOE-HEP as a second-generation dark matter experiment. Witherell is the Level 2 manager for the Outer Detector System on the LUX-Zeplin experiment.

Witherell, Michael S.

2014-10-02

213

China Energy Efficiency Round Robin Testing Results for Room  

E-print Network

LBNL-3502E China Energy Efficiency Round Robin Testing Results for Room Air Conditioners Nan Zhou Round Robin Testing Results and Analysis by China National Institute of Standardization..................................................................................................................... 1 I.1.1 China's Energy Constraint Problem and the Need to Improve the Energy Efficiency of Energy

214

Experimental study on temperature characteristics and energy conversion in packed bed reactor with dielectric barrier discharge  

NASA Astrophysics Data System (ADS)

The temperature characteristics and energy conversion in packed bed reactor combined with a dielectric barrier discharge (DBD) plasma was investigated experimentally. The pellet temperatures of two types packed bed reactor, cylindrical reactor and parallel-plate reactor, was measured in conditions of various inlet voltage of DBD plasma. The relationship between pellet temperature of the packed bed and applied voltage of DBD plasma was discovered. The experimental result indicates a tendency that the pellet temperature of packed bed increases as the applied voltage of inlet plasma increases. When the voltage of inlet plasma is high enough, the pellet temperature increment decreases. Simultaneously,the packed bed temperature is sensitive to the inlet plasma energy and there is a potential application to heat exchanger. Moreover the proportion of energy consumption of plasma inputting into packed bed reactor was analyzed and calculated. The mechanisms that electrical energy of inlet plasma is transformed into heat energy in the two phases, gaseous and pellets of the packed bed reactor are different. The energy consumption in pellet phase is dielectric polarization loss and depends on packed bed geometry and DBD plasma etc. The energy consumption in gaseous phase is plasma sheath procedure. The important factors effecting on gas discharge are gaseous component and voltage, frequency of power.

Li, Sen; Tang, Zuchen; Gu, Fan

2010-10-01

215

Three-dimensional convection in horizontal cylinders - Numerical solutions and comparison with experimental and analytical results  

NASA Technical Reports Server (NTRS)

The results of a three-dimensional numerical simulation of Boussinesq free convection in a horizontal differentially heated cylinder are presented. The computation was based on a Samarskii-Andreyev scheme (described by Leong, 1981) and a false-transient advancement in time, with vorticity, velocity, and temperature as dependent variables. Solutions for velocity and temperature distributions were obtained for Rayleigh numbers (based on the radius) Ra = 74-18,700, thus covering the core- and boundary-layer-driven regimes. Numerical solutions are compared with asymptotic analytical solutions and experimental data. The numerical results well represent the complex three-dimensional flows found experimentally.

Smutek, C.; Bontoux, P.; Roux, B.; Schiroky, G. H.; Hurford, A. C.

1985-01-01

216

Three-dimensional convection in horizontal cylinders - Numerical solutions and comparison with experimental and analytical results  

NASA Astrophysics Data System (ADS)

The results of a three-dimensional numerical simulation of Boussinesq free convection in a horizontal differentially heated cylinder are presented. The computation was based on a Samarskii-Andreyev scheme (described by Leong, 1981) and a false-transient advancement in time, with vorticity, velocity, and temperature as dependent variables. Solutions for velocity and temperature distributions were obtained for Rayleigh numbers (based on the radius) Ra = 74-18,700, thus covering the core- and boundary-layer-driven regimes. Numerical solutions are compared with asymptotic analytical solutions and experimental data. The numerical results well represent the complex three-dimensional flows found experimentally.

Smutek, C.; Bontoux, P.; Roux, B.; Schiroky, G. H.; Hurford, A. C.

217

Some experimental results on physical level protocol for computer network via Japanese communication satellite  

NASA Astrophysics Data System (ADS)

Experimental results of the physical level protocol for a computer network consisting of the communication satellite 30/20 GHz band are described. The experiment employed a network configuration including a central large earth station and many associated small user stations sharing an SCPC channel by a TDMA-like multiple access method. Each small user station has an antenna measuring two meters in diameter. The channel data rate is 64 kbit/s with QPSK connected with error correction of rate 3/4 convolutional code. Experimental results are presented on the bit error rate vs. C/N, packet error rate vs. C/N, and burst synchronization characteristics.

Matsumoto, K.; Uchida, K.; Kakinuma, Y.; Sakagami, S.; Ito, A.; Shikatani, M.; Takahashi, H.

1984-03-01

218

Experimental results for H2 formation from H- and H and implications for first star formation  

NASA Astrophysics Data System (ADS)

We have performed the first energy-resolved measurement of the associative detachment (AD) reaction H-+ H ? H2-? H2+ e-, which is the dominant process forming molecular hydrogen in the early universe. We find excellent agreement between our measurements and the most recent theoretical calculation of the AD process. We also present model calculations of the formation of protogalaxies in the early universe uitilizing the experimentally confirmed rate coefficient.

Kreckel, Holger; Bruhns, Hjalmar; ?ížek, Martin; Glover, Simon C. O.; Miller, Kenneth A.; Urbain, Xavier; Savin, Daniel W.

2015-01-01

219

EXPERIMENTAL TYPE OF AN ECOLOGICAL POWER STATION BASED ON THE ENERGY OF SEA WAVES  

Microsoft Academic Search

Experimental type of the sea ecological power station handled in this research task follow the acquiring electric energy and different forms of energy through: picking up and transforming waves energy in alternative rectilinear movement and converting it to rotation movement, and afterwards in electric energy; transforming alternative movement of swimmers in pneumatic energy and straight in electric energy; obtaining clean

Maria MOISE; Carmen Cristiana BUCUR; Silvia Adina CRISTEA

220

Experimental and calculational results of an irradiation experiment in EBR-II  

SciTech Connect

During the period from 1967 to 1970, several actinide samples were irradiated by ANL in the fast reactor EBR-II for approximately 10/sup 23/ nvt. In 1978, ORNL began an experimental determination of the exposure products in the irradiated samples, and to date, 12 of the samples have already been analyzed. In a previous paper preliminary experimental results for /sup 239/Pu sample were compared with the exposure products predicted by calculations. In this paper, the comparison is extended to samples of /sup 238/U, /sup 233/U, /sup 232/Th, /sup 240/Pu, /sup 237/Np, and a second /sup 239/Pu sample, with the calculations utilizing the recently released ENDF/B-V data and improved modeling approximations. The experimental results presented in this paper represent a fairly comprehensive set of measurements of actinide burnup in a fast reactor spectrum.

Gilai, D.; Cooper, J.H.; Laing, W.R.; Raman, S.; Stelson, P.H.; Walker, R.L.; Williams, M.L.

1981-01-01

221

TRANSCRITICAL CO2 MOBILE HEAT PUMP AND A\\/C SYSTEM EXPERIMENTAL AND MODEL RESULTS  

Microsoft Academic Search

This article presents the results of the experimental runs of a prototype of R744 (CO2) refrigeration system operating in a both air conditioning and heat pump mode when heat rejection is done in supercritical region. The prototype system is sized for a compact car. Data presented are in the limited range of operation. Further optimization and extension of operating range

C. W. Bullard; J. M. Yin; P. S. Hrnjak

222

Probing a cold surface with slow heavy-atom scattering: Experimental results and theoretical calculations  

E-print Network

Probing a cold surface with slow heavy-atom scattering: Experimental results and theoretical manuscript received 20 September 2001; published 2 January 2002 Slow heavy atoms scattering from cold, which is slow and strong, it is typically much more complex.2 In the common case of a light particle

Burke, Kieron

223

EXPERIMENTAL RESULTS ON THE QUENCHING OF THE MAGNETIC MOMENT OF THE RARE EARTH ION IN GARNETS  

Microsoft Academic Search

One is led to assume that the orbital magnetic moment of the rare earth ; ions in ferrimagnetie garnets is quenched at low temperature. By comparing the ; experimental results on gallates and ferrites with the behavior of the Gd\\/sup 3+\\/ ; ion, the importance of this effect for Dy\\/sup 3+\\/, Er\\/sup 3+\\/, and Yb\\/sup 3+\\/ and ; its dependence

Pauthenet

1959-01-01

224

The Effects of Local Ionospheric Decorrelation on LAAS: Theory and Experimental Results  

E-print Network

increases, the lines of sight will travel through different parts of the ionosphere. For a single frequencyThe Effects of Local Ionospheric Decorrelation on LAAS: Theory and Experimental Results Jock R. I adverse effects of the ionosphere on the millions of GPS users. The introduction of the Global Positioning

Stanford University

225

Far field of large circular loop antennas: Theoretical and experimental results  

Microsoft Academic Search

Far field patterns of large circular loop antennas of circumferences up to two and one-half wavelengths were calculated using Storer's theory for the current distribution on the antenna. To verify the theory, radiation pattern measurements were made at 3 GHz; the experimental results are in good qualitative agreement with theory.

B. Rao

1968-01-01

226

Geometric Scaling Effects in Electrical Field Flow Fractionation. 2. Experimental Results  

E-print Network

Geometric Scaling Effects in Electrical Field Flow Fractionation. 2. Experimental Results Bruce K, concentration) as well as for a primary separation tool is the miniaturized field flow fractionation (FFF associated with electrical field flow fractionation (EFFF) systems.8 The theoretical study and other papers

227

C Gormezano ENEA Frascati Italy/ MIT presentation 9 February 2001 FTU: Experimental Results and Prospects  

E-print Network

C Gormezano ENEA Frascati Italy/ MIT presentation 9 February 2001 FTU: Experimental Results Frascati #12;C Gormezano ENEA Frascati Italy/ MIT presentation 9 February 2001 FTU Experiment ctd-200keV , 17 chords #12;C Gormezano ENEA Frascati Italy/ MIT presentation 9 February 2001 FTU

228

images/UMDlog Measuring photoactivity with a potentiostat Our experimental setup Preliminary results Time Scales  

E-print Network

results Time Scales Cu2O for water splitting RAA Laboratory Department of Chemical & Biomolecular Engineering Department Insitute for Systems Research University of Maryland March 28, 2012 Support: NSF CBET wire Platinum coiled wire Cu2 O on Cu 1''x1'' Cu 1''x1'' RAA Lab Electrolysis Experimental setup 150 W

Ehrman, Sheryl H.

229

Some experimental results on physical level protocol for computer network via Japanese communication satellite  

Microsoft Academic Search

Experimental results of the physical level protocol for a computer network consisting of the communication satellite 30\\/20 GHz band are described. The experiment employed a network configuration including a central large earth station and many associated small user stations sharing an SCPC channel by a TDMA-like multiple access method. Each small user station has an antenna measuring two meters in

K. Matsumoto; K. Uchida; Y. Kakinuma; S. Sakagami; A. Ito; M. Shikatani; H. Takahashi

1984-01-01

230

A Robust Torque Controller for Induction Motors Without Rotor Position Sensor: Analysis and Experimental Results  

E-print Network

is detailed in a recent book [1]. The operation of an induction motor as part of a `high performance drive and Experimental Results E.G.Strangas, H.K.Khalil, B. Al Oliwi, L. Laubinger Department of Electrical Engineering. Introduction High performance induction motor drives based on `Field Orientation' have been commercially

Strangas, Elias G.

231

Photon Detection with Cooled Avalanche Photodiodes: Theory and Preliminary Experimental Results  

NASA Technical Reports Server (NTRS)

Avalanche photodiodes (APDs) can be operated in a geiger-tube mode so that they can respond to single electron events and thus be used as photon counting detectors. Operational characteristics and theory of APDs while used in this mode are analyzed and assessed. Preliminary experimental investigation of several commercially available APDs has commenced, and initial results for dark count statistics are presented.

Robinson, D. L.; Hays, D. A.

1985-01-01

232

Experimental results on adaptive output feedback control using a laboratory model helicopter  

Microsoft Academic Search

Experimental results are presented that illustrate a recently developed method for adaptive output feedback control. The method permits adaptation to both parametric uncertainty and unmodeled dynamics, and incorporates a novel approach that permits adaptation under known actuator characteristics including actuator dynamics and saturation. Only knowledge of the relative degree of the controlled system within the bandwidth of the control design

Ali T. Kutay; Anthony J. Calise; Moshe Idan; Naira Hovakimyan

2005-01-01

233

Abstract--This paper describes experimental results aiming at analyzing lithium-ion batteries performances  

E-print Network

Abstract--This paper describes experimental results aiming at analyzing lithium-ion batteries (SOH) of cells. Index Terms--Lithium-ion batteries, Aging, EIS, State Of Charge, State Of Health, Fuzzy Logic System. I. INTRODUCTION Lithium ion secondary batteries are now being used in wide applications

Boyer, Edmond

234

Dynamics of Dual Prism Adaptation: Relating Novel Experimental Results to a Minimalistic Neural Model  

E-print Network

Dynamics of Dual Prism Adaptation: Relating Novel Experimental Results to a Minimalistic Neural direct effect, i.e. adaptation to prisms, and aftereffect, i.e. behavior after removal of prisms transfer and generalization of prism adaptation, as observed in other experiments. Citation: Are´valo O

Kreiter, Andreas K.

235

The analysis of time-resolved optically stimulated luminescence: II. Computer simulations and experimental results  

Microsoft Academic Search

This is the second in a set of paired papers on the analysis of time-resolved optically stimulated luminescence. This paper compares experimental results and computer simulations with corresponding conceptual models discussed in the first of this set of papers. The evaluation of principal and subsidiary luminescence lifetimes from time-resolved luminescence spectra measured during or after pulsed optical stimulation is illustrated

M. L. Chithambo

2007-01-01

236

Experimental Results for and Theoretical Analysis of a Self-Organizing Global Coordinate  

E-print Network

estimates to globally accessible beacons such as the Global Positioning System [6], indoor localization [1Experimental Results for and Theoretical Analysis of a Self-Organizing Global Coordinate System to the global coordinate system. Ad hoc sensor networks present novel tradeoffs in system design. On the one

Napp, Nils

237

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Experimental Results  

E-print Network

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Experimental Results C. Canudas dynamic friction force model for the longitudinal road/tire interaction for wheeled ground vehicles is val- idated via experiments with an actual passenger vehicle. Contrary to common static friction/slip maps

Tsiotras, Panagiotis

238

Broadband optical cavities for infrared free electron lasers: analysis and preliminary experimental results  

SciTech Connect

In this work we describe the complete design of a broadband optical cavity for a new IR free electron laser under construction at Stanford using the first section of the Mark III linac. Although the numerical results apply specifically to the Mark III FEL, the general scheme is applicable to any tunable free electron laser. In the last section, some preliminary experimental results for the acoustooptic output coupler are reported and discussed.

Cutolo, A.; Khuri-Yakub, B.T.; Madey, J.M.J.

1984-09-01

239

Design and Experimental Results for a Natural-Laminar-Flow Airfoil for General Aviation Applications  

NASA Technical Reports Server (NTRS)

A natural-laminar-flow airfoil for general aviation applications, the NLF(1)-0416, was designed and analyzed theoretically and verified experimentally in the Langley Low-Turbulence Pressure Tunnel. The basic objective of combining the high maximum lift of the NASA low-speed airfoils with the low cruise drag of the NACA 6-series airfoils was achieved. The safety requirement that the maximum lift coefficient not be significantly affected with transition fixed near the leading edge was also met. Comparisons of the theoretical and experimental results show excellent agreement. Comparisons with other airfoils, both laminar flow and turbulent flow, confirm the achievement of the basic objective.

Somers, D. M.

1981-01-01

240

Non-destructive evaluation of metal-to-metal adhesive joints using vibration analysis: experimental results  

NASA Astrophysics Data System (ADS)

Vibration based non-destructive evaluation shows promise for damage detection in metal-to-metal adhesive joints. This research investigates an experimental technique to diagnose damage in single-lap adhesive joints subject to cyclical tensile loading. Vibration analysis reveals that damage can be correlated with changes in identified modal damping ratios. Constant amplitude forcing functions are employed to eliminate amplitude-dependent nonlinearities in the dynamic response profiles. Damping estimates obtained from time-domain analyses correlate well with damage magnitudes. Finite element modal analysis of the lap joints supports the experimental results.

Pandurangan, Pradeep; Buckner, Gregory D.

2006-03-01

241

Experimental demonstration of energy-chirp compensation by a tunable dielectric-based structure.  

PubMed

A tunable energy-chirp compensator was used to remove a correlated energy chirp from the 60-MeV beam at the Brookhaven National Laboratory Accelerator Test Facility. The compensator operates through the interaction of the wakefield of the electron bunch with itself and consists of a planar structure comprised of two alumina bars with copper-plated backs separated by an adjustable beam aperture. By changing the gap size, the correlated energy chirp of the electron bunch was completely removed. Calculations show that this device, properly scaled to account for the electron bunch charge and length, can be used to remove residual correlated energy spread at the end of the linacs used for free-electron lasers. The experimental results are shown to be in good agreement with numerical simulations. Application of this technique can significantly simplify linac design and improve free-electron lasers performance. PMID:24702378

Antipov, S; Baturin, S; Jing, C; Fedurin, M; Kanareykin, A; Swinson, C; Schoessow, P; Gai, W; Zholents, A

2014-03-21

242

Experimental validation of a novel compact focusing scheme for future energy-frontier linear lepton colliders.  

PubMed

A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed in 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This scheme has many advantageous properties over previously studied focusing schemes, including being significantly shorter for a given energy and having a significantly better energy bandwidth. Experimental results from the ATF2 accelerator at KEK are presented that validate the operating principle of such a scheme by demonstrating the demagnification of a 1.3 GeV electron beam down to below 65 nm in height using an energy-scaled version of the compact focusing optics designed for the ILC collider. PMID:24484144

White, G R; Ainsworth, R; Akagi, T; Alabau-Gonzalvo, J; Angal-Kalinin, D; Araki, S; Aryshev, A; Bai, S; Bambade, P; Bett, D R; Blair, G; Blanch, C; Blanco, O; Blaskovic-Kraljevic, N; Bolzon, B; Boogert, S; Burrows, P N; Christian, G; Corner, L; Davis, M R; Faus-Golfe, A; Fukuda, M; Gao, J; García-Morales, H; Geffroy, N; Hayano, H; Heo, A Y; Hildreth, M; Honda, Y; Huang, J Y; Hwang, W H; Iwashita, Y; Jang, S; Jeremie, A; Kamiya, Y; Karataev, P; Kim, E S; Kim, H S; Kim, S H; Kim, Y I; Komamiya, S; Kubo, K; Kume, T; Kuroda, S; Lam, B; Lekomtsev, K; Liu, S; Lyapin, A; Marin, E; Masuzawa, M; McCormick, D; Naito, T; Nelson, J; Nevay, L J; Okugi, T; Omori, T; Oroku, M; Park, H; Park, Y J; Perry, C; Pfingstner, J; Phinney, N; Rawankar, A; Renier, Y; Resta-López, J; Ross, M; Sanuki, T; Schulte, D; Seryi, A; Shevelev, M; Shimizu, H; Snuverink, J; Spencer, C; Suehara, T; Sugahara, R; Takahashi, T; Tanaka, R; Tauchi, T; Terunuma, N; Tomás, R; Urakawa, J; Wang, D; Warden, M; Wendt, M; Wolski, A; Woodley, M; Yamaguchi, Y; Yamanaka, T; Yan, J; Yokoya, K; Zimmermann, F

2014-01-24

243

Experimental Demonstration of Energy-Chirp Compensation by a Tunable Dielectric-Based Structure  

NASA Astrophysics Data System (ADS)

A tunable energy-chirp compensator was used to remove a correlated energy chirp from the 60-MeV beam at the Brookhaven National Laboratory Accelerator Test Facility. The compensator operates through the interaction of the wakefield of the electron bunch with itself and consists of a planar structure comprised of two alumina bars with copper-plated backs separated by an adjustable beam aperture. By changing the gap size, the correlated energy chirp of the electron bunch was completely removed. Calculations show that this device, properly scaled to account for the electron bunch charge and length, can be used to remove residual correlated energy spread at the end of the linacs used for free-electron lasers. The experimental results are shown to be in good agreement with numerical simulations. Application of this technique can significantly simplify linac design and improve free-electron lasers performance.

Antipov, S.; Baturin, S.; Jing, C.; Fedurin, M.; Kanareykin, A.; Swinson, C.; Schoessow, P.; Gai, W.; Zholents, A.

2014-03-01

244

Experimental and numerical study of cellulose-based electro-active paper energy harvester  

NASA Astrophysics Data System (ADS)

In this present study experimental and finite element analysis of cellulose based electro-active paper energy harvester is presented. Electro-active paper coated with metal electrode is a smart form of cellulose and exhibit piezoelectric effect. Specimens were prepared by depositing electrodes on both sides of the cellulose film. A 50 mm x 50 mm cellulose film coated with aluminum electrodes was bonded on 100 mm x 50 mm x 1 mm aluminum host structure. The voltage output to input acceleration frequency response across a load resistor of 1 M? is recorded by conventional energy harvesting experimental setup at the fundamental vibration mode of the EAPap cantilever beam. A coupled piezoelectric-circuit finite element model is developed in which load resistor is directly connected to energy scavenging device. Voltage output FRF is measured for the cases, without proof mass, and by adding a 2 grams proof mass near the tip of the cantilever. The experimental voltage FRF value is 7.6 V/g at 75.1 Hz and is improved to 13.8 V/g at 62.2 Hz when a stainless steel proof mass of 2 grams is added. The presented CPC-FEM model results agree reasonably well with the experimental results. Despite the fact that the electro-mechanical coupling coefficient of electro-active paper is lower than other available piezoelectric materials, it is biocompatible, cheap and naturally occurring polymeric material. It is also very flexible and posses similar piezoelectric characteristics such a PVDF which inspire to use EAPap in energy harvesting applications.

Abas, Zafar; Kim, Heung Soo; Zhai, Lindong; Kim, Jaehwan

2014-04-01

245

Experimental and theoretical high energy physics research. [UCLA  

SciTech Connect

Progress in the various components of the UCLA High-Energy Physics Research program is summarized, including some representative figures and lists of resulting presentations and published papers. Principal efforts were directed at the following: (I) UCLA hadronization model, PEP4/9 e{sup +}e{sup {minus}} analysis, {bar P} decay; (II) ICARUS and astroparticle physics (physics goals, technical progress on electronics, data acquisition, and detector performance, long baseline neutrino beam from CERN to the Gran Sasso and ICARUS, future ICARUS program, and WIMP experiment with xenon), B physics with hadron beams and colliders, high-energy collider physics, and the {phi} factory project; (III) theoretical high-energy physics; (IV) H dibaryon search, search for K{sub L}{sup 0} {yields} {pi}{sup 0}{gamma}{gamma} and {pi}{sup 0}{nu}{bar {nu}}, and detector design and construction for the FNAL-KTeV project; (V) UCLA participation in the experiment CDF at Fermilab; and (VI) VLPC/scintillating fiber R D.

Not Available

1992-01-01

246

Evaluating impacts of CO2 gas intrusion into a confined sandstone aquifer: Experimental results  

SciTech Connect

Deep subsurface storage and sequestration of CO2 has been identified as a potential mitigation technique for rising atmospheric CO2 concentrations. Sequestered CO2 represents a potential risk to overlying aquifers if the CO2 leaks from the deep storage reservoir. Experimental and modeling work is required to evaluate potential risks to groundwater quality and develop a systematic understanding of how CO2 leakage may cause important changes in aquifer chemistry and mineralogy by promoting dissolution/precipitation, adsorption/desorption, and redox reactions. Sediments from the High Plains aquifer in Kansas, United States, were used in this investigation, which is part of the National Risk Assessment Partnership Program sponsored by the US Department of Energy. This aquifer was selected to be representative of consolidated sand and gravel/sandstone aquifers overlying potential CO2 sequestration repositories within the continental US. In this paper, we present results from batch experiments conducted at room temperature and atmospheric pressure with four High Plains aquifer sediments. Batch experiments simulate sudden, fast, and short-lived releases of the CO2 gas as would occur in the case of well failure during injection. Time-dependent release of major, minor, and trace elements were determined by analyzing the contacting solutions. Characterization studies demonstrated that the High Plains aquifer sediments were abundant in quartz and feldspars, and contained about 15 to 20 wt% montmorillonite and up to 5 wt% micas. Some of the High Plains aquifer sediments contained no calcite, while others had up to about 7 wt% calcite. The strong acid extraction tests confirmed that in addition to the usual elements present in most soils, rocks, and sediments, the High Plains aquifer sediments had appreciable amounts of As, Cd, Pb, Cu, and occasionally Zn, which potentially may be mobilized from the solid to the aqueous phase during or after exposure to CO2. However, the results from the batch experiments showed that the High Plains sediments mobilized only low concentrations of trace elements (potential contaminants), which were detected occasionally in the aqueous phase during these experiments. Importantly, these occurrences were more frequent in the calcite-free sediment. Results from these investigations provide useful information to support site selection, risk assessment, and public education efforts associated with geological CO2 storage and sequestration.

Qafoku, Nikolla; Lawter, Amanda R.; Shao, Hongbo; Wang, Guohui; Brown, Christopher F.

2014-12-31

247

OVERVIEW OF RECENT EXPERIMENTAL RESULTS FROM THE DIII-D ADVANCED TOKAMAK PROGRAM  

SciTech Connect

OAK A271 OVERVIEW OF RECENT EXPERIMENTAL RESULTS FROM THE DIII-D ADVANCED TOKAMAK PROGRAM. The DIII-D research program is developing the scientific basis for advanced tokamak (AT) modes of operation in order to enhance the attractiveness of the tokamak as an energy producing system. Since the last International Atomic Energy Agency (IAEA) meeting, the authors have made significant progress in developing the building blocks needed for AT operation: (1) the authors have doubled the magnetohydrodynamic (MHD) stable tokamak operating space through rotational stabilization of the resistive wall mode; (2) using this rotational stabilization, they have achieved {beta}{sub N}H{sub 89} {le} 10 for 4 {tau}{sub E} limited by the neoclassical tearing mode; (3) using real-time feedback of the electron cyclotron current drive (ECCD) location, they have stabilized the (m,n) = (3,2) neoclassical tearing mode and then increased {beta}{sub T} by 60%; (4) they have produced ECCD stabilization of the (2,1) neoclassical tearing mode in initial experiments; (5) they have made the first integrated AT demonstration discharges with current profile control using ECCD; (6) ECCD and electron cyclotron heating (ECH) have been used to control the pressure profile in high performance plasmas; and (7) they have demonstrated stationary tokamak operation for 6.5 s (36 {tau}{sub E}) at the same fusion gain parameter of {beta}{sub N}H{sub 89}/q{sub 95}{sup 2} {approx} 0.4 as ITER but at much higher q{sub 95} = 4.2. They have developed general improvements applicable to conventional and advanced tokamak operating modes: (1) they have an existence proof of a mode of tokamak operation, quiescent H-mode, which has no pulsed, ELM heat load to the divertor and which can run for long periods of time (3.8 s or 25 {tau}{sub E}) with constant density and constant radiation power; (2) they have demonstrated real-time disruption detection and mitigation for vertical disruption events using high pressure gas jet injection of noble gases; (3) they have found that the heat and particle fluxes to the inner strike points of balanced, double-null divertors are much smaller than to the outer strike points.

BURRELL,KH

2002-11-01

248

Propagation effects for land mobile satellite systems: Overview of experimental and modeling results  

NASA Astrophysics Data System (ADS)

Models developed and experiments performed to characterize the propagation environment associated with land mobile communication using satellites are discussed. Experiments were carried out with transmitters on stratospheric balloons, remotely piloted aircraft, helicopters, and geostationary satellites. This text is comprised of compiled experimental results for the expressed use of communications engineers, designers of planned Land Mobile Satellite Systems (LMSS), and modelers of propagation effects. The results presented here are mostly derived from systematic studies of propagation effects for LMSS geometries in the United States associated with rural and suburban regions. Where applicable, the authors also draw liberally from the results of other related investigations in Canada, Europe, and Australia. Frequencies near 1500 MHz are emphasized to coincide with frequency bands allocated for LMSS by the International Telecommunication Union, although earlier experimental work at 870 MHz is also included.

Goldhirsh, Julius; Vogel, Wolfhard J.

1992-02-01

249

Predictions of the equation of state of cerium yield interesting insights into experimental results  

SciTech Connect

There has been much interest in the past in understanding the dynamic properties of phase changing materials. In this paper we begin to explore the dynamic properties of the complex material of cerium. Cerium metal is a good candidate material to explore capabilities in determining a dynamic phase diagram on account of its low dynamic phase boundaries, namely, the {gamma}-{alpha}, and {alpha}-liquid phase boundaries. Here we present a combination of experimental results with calculated results to try to understand the dynamic behavior of the material. Using the front surface impact technique, we performed a series of experiments which displayed a rarefaction shock upon release. These experiments show that the reversion shock stresses occur at different magnitudes, allowing us to plot out the {gamma}-{alpha} phase boundary. Applying a multiphase equation of state a broader understanding of the experimental results will be discussed.

Cherne, Frank J [Los Alamos National Laboratory; Jensen, Brian J [Los Alamos National Laboratory; Rigg, Paulo A [Los Alamos National Laboratory; Elkin, Vyacheslav M [VNIITF

2009-01-01

250

Phase Partitioning of Common Alcohols With BTEX Compounds in Water: Comparison Between Modeling and Experimental Results  

NASA Astrophysics Data System (ADS)

This study compares the modeling and experimental results on the equilibrium phase partitioning behavior of three common alcohols (ethanol, isopropanol, and methanol) in a two-phase system consisting of water and a BTEX compound. A previously developed computer program is used to generate ternary phase diagrams for each alcohol-water-NAPL mixture combination, where the required activity coefficients are estimated using the UNIFAC model. A set of laboratory experiments is conducted to determine the maximum single-phase water content for every alcohol-water-NAPL mixture combination considered in this study, where the initial volume composition is 85 percent alcohol and 15 percent NAPL. Comparison of experimental results against UNIFAC- derived modeling results shows good agreement for mixtures containing ethanol and methanol, but relatively poor agreement for mixtures containing isopropanol.

Lee, K. Y.

2007-12-01

251

Propagation effects for land mobile satellite systems: Overview of experimental and modeling results  

NASA Technical Reports Server (NTRS)

Models developed and experiments performed to characterize the propagation environment associated with land mobile communication using satellites are discussed. Experiments were carried out with transmitters on stratospheric balloons, remotely piloted aircraft, helicopters, and geostationary satellites. This text is comprised of compiled experimental results for the expressed use of communications engineers, designers of planned Land Mobile Satellite Systems (LMSS), and modelers of propagation effects. The results presented here are mostly derived from systematic studies of propagation effects for LMSS geometries in the United States associated with rural and suburban regions. Where applicable, the authors also draw liberally from the results of other related investigations in Canada, Europe, and Australia. Frequencies near 1500 MHz are emphasized to coincide with frequency bands allocated for LMSS by the International Telecommunication Union, although earlier experimental work at 870 MHz is also included.

Goldhirsh, Julius; Vogel, Wolfhard J.

1992-01-01

252

Experimental study of targeted energy transfer from an acoustic system to a nonlinear membrane absorber  

NASA Astrophysics Data System (ADS)

This paper deals with the application of the concept of targeted energy transfer to the field of acoustics, providing a new approach to passive sound control in the low frequency domain, where no efficient dissipative mechanism exists. The targeted energy transfer, also called energy pumping, is a phenomenon that we observe by combining a pure nonlinear oscillator with a linear primary system. It corresponds to an almost irreversible transfer of vibration energy from the linear system to the auxiliary nonlinear one, where the energy is finally dissipated. In this study, an experimental set-up has been developed using the air inside a tube as the acoustic linear system, a thin circular visco-elastic membrane as an essentially cubic oscillator and the air inside a box as a weak coupling between those two elements. In this paper, which mainly deals with experimental results, it is shown that several regimes exist under sinusoidal forcing, corresponding to the different nonlinear normal modes of the system. One of these regimes is the quasi-periodic energy pumping regime. The targeted energy transfer phenomenon is also visible on the free oscillations of the system. Indeed, above an initial excitation threshold, the sound extinction in the tube follows a quasi-linear decrease that is much faster than the usual exponential one. During this linear decrease, the energy of the acoustic medium is irreversibly transferred to the membrane and then damped into this element called nonlinear energy sink. We present also the frequency responses of the system which shows a clipping of the original resonance peak of the acoustic medium and we finally demonstrate the ability of the nonlinear absorber to operate in a large frequency band, tuning itself to any linear system.

Bellet, R.; Cochelin, B.; Herzog, P.; Mattei, P.-O.

2010-07-01

253

Review on optical constants of Titan aerosols: Experimental results and modeling/observational data  

NASA Astrophysics Data System (ADS)

During the last years many studies have been performed to improve the experimental database of optical constants of Titan aerosols. Indeed, the determination of the optical constants of these particles is essential to quantify their capacity to absorb and to scatter solar radiation, and thus to evaluate their role on Titan's radiative balance and climate. The study of optical properties is also crucial to analyze and to better interpret many of Titan's observational data, in particular those acquired during the Cassini-Huygens mission. One way to determine Titan aerosols optical constant is to measure the optical constants of analogues of Titan complex organic material synthesized in the laboratory, usually named Titan's tholins (Sagan and Khare, 1979). But the optical constants depend on the chemical composition, the size and the shape of particles (Raulin et al., 2012). Those three parameters result from the experimental conditions such as energy source, gas mixing ratio, gas pressure, flow rate and irradiation time (Cable et al., 2012). Besides the determination of the refractive index in the laboratory, there are others methods using theoretical models or observational data. Nevertheless, theoretical models are based on laboratory data or/and observational data. The visible - near infrared spectral region of optical constants has been widely studied with laboratory analogues. Comparison of the obtained results suggest that tholins synthesized by Tran et al. (2003) and Majhoub et al. (2012) are the best representative of Titan aerosols with regards to their refractive indexes in this spectral region. The mid-infrared spectral range has been studied only by Imanaka et al. (2012) and slightly by Tran et al. (2003). In that spectral range, Titan tholins do not exhibit the features displayed by Kim and Courtin (2013) from Titan's observations. For spectral region of wavelengths smaller than 0.20µm or higher than 25µm, only the data from Khare et al. (1984) are available. Therefore it would be very useful to get more laboratory data and especially from Tran et al (2013), Mahjoub et al. (2012) and Imanaka et al. (2012) samples in these spectral regions since their refractive indexes match observational and theoretical data in other spectral ranges. This presentation will critically summarize these recent results and present detailled constraints on the optical constants Titan's aerosols. In addition, specific lacks of data will be highlighted as well as some possible investigations to be carried out to fill these gaps. References: Cable, M. L., et al., 2012. Titan Tholins: Simulating Titan Organic Chemistry in the Cassini-Huygens Era. Chemical Reviews. 112, 1882-1909. Imanaka, H., et al., 2012. Optical constants of Titan tholins at mid-infrared wavelengths (2.5-25 µm) and the possible chemical nature of Titan's haze particles. Icarus. 218, 247-261. Khare, B. N., et al., 1984. Optical-Constants of Organic Tholins Produced in a Simulated Titanian Atmosphere - from Soft-X-Ray to Microwave-Frequencies. Icarus. 60, 127-137. Kim, S. J., Courtin, R., 2013. Spectral characteristics of the Titanian haze at 1-5 micron from Cassini/VIMS solar occultation data. Astronomy & Astrophysics. 557, L6. Mahjoub, A., et al., 2012. Influence of methane concentration on the optical indices of Titan's aerosols analogues. Icarus. 221, 670-677. Raulin, F., et al., 2012. Prebiotic-like chemistry on Titan. Chemical Society Reviews. 41, 5380-5393. Sagan, C., Khare, B. N., 1979. Tholins - Organic-Chemistry of Inter-Stellar Grains and Gas. Nature. 277, 102-107. Tran, B. N., et al., 2003. Simulation of Titan haze formation using a photochemical flow reactor - The optical constants of the polymer. Icarus. 165, 379-390. Acknowledgements: We acknowledge support from the French Space Agency (CNES) and the European Space Agency (ESA).

Brassé, Coralie; Muñoz, Olga; Coll, Patrice; Raulin, François

2014-05-01

254

Au L? x-rays induced by photons from 241Am: Comparison of experimental results and the predictions of PENELOPE.  

PubMed

The results of experiments performed, measuring the L? x-rays emitted by Au due to excitation by photons of various energies from an (241)Am sample at forward-scattered angles in the range 0° to 65°, are compared to the predictions of the Monte Carlo code, PENELOPE. The experimental data are in good agreement with the predictions of the program. A comparison of the angular distributions of the probability densities (as predicted by the program) related to the Au L? and L? x-rays suggests that PENELOPE does not simulate the phenomena described by Flügge et al. (1972). PMID:21890370

Gonzales, D; Requena, S; Williams, S

2012-01-01

255

A liquid Xenon Positron Emission Tomograph for small animal imaging : first experimental results of a prototype cell  

E-print Network

A detector using liquid Xenon (LXe) in the scintillation mode is studied for Positron Emission Tomography (PET) of small animals. Its specific design aims at taking full advantage of the Liquid Xenon scintillation properties. This paper reports on energy, time and spatial resolution capabilities of the first LXe prototype module equipped with a Position Sensitive Photo- Multiplier tube (PSPMT) operating in the VUV range (178 nm) and at 165 K. The experimental results show that such a LXe PET configuration might be a promising solution insensitive to any parallax effect.

Gallin-Martel, M L; Grondin, Y; Rossetto, O; Collot, J; Grondin, D; Jan, S; Martin, Ph; Mayet, F; Petit, P; Vezzu, F

2008-01-01

256

UVA experimental and high energy physics. Final grant report  

SciTech Connect

The period 1992--1997 was a mixture of frustrations and of accomplishments for the UVa HEP group. The experimental HEP group began this period with the completion of a truncated run of Experiment E771 at Fermilab in 1992. This experiment was designed to measure the cross section for beauty production in 800 GeV/c pN interactions. It succeeded in this goal as well as in obtaining one of the best limits on FCNC in charm decays by setting an upper limit on D{sup 0} {r_arrow} {mu}{sup +}{mu}{sup {minus}}. In addition, they were able to measure {Psi}, {Psi}, {chi}{sub 1},{chi}{sub 2} and upsilon production. Three UVa PhD theses have resulted from this experiment (as well as 12 other PhD's at other institutions). At the same time, the UVa experimental group was vigorously pursuing the goal of studying CP violation in B production. This took the form of a proposal to the SSC for a super fixed target facility, the SFT, which would focus on studies of B mesons. B. Cox was the spokesman of this experiment that had over thirty institutions. This proposal EOI-14 had a good reception by the SSC PAC. A R and D activity to prove the technique of crystal channeling was undertaken to prove the accelerator aspects of this proposal. This activity, known as E853 or CEX at Fermilab, resulted in proof of the crystal channeling technique as viable for the extraction of 20 TeV beam at the SSC. In addition to this activity, the UVa group investigated many other aspects of B physics at the SSC. They were among the leaders of the 1993 Snowmass meeting on B Physics at Hadronic Accelerators. The UVa HEP group worked vigorously on developing the ideas for B physics at the SSC, as evidenced by the many different studies listed in the publication list given, up to the very day the SSC was terminated by an act of Congress.

Cox, B.

1999-10-07

257

Experimental Study of High-Energy Processing of Protoplanetary Materials  

NASA Astrophysics Data System (ADS)

The metal-silicate fractionation in celestial bodies effectively separates siderophile 182W from lithophile 182Hf into the core and mantle, respectively, making the Hf-W chronometer ideal for dating core-formation in differentiated planetary bodies. It is generally believed that there was equilibration of the Hf-W system during primary metal-silicate fractionation of small, initially chondritic, parent bodies. However, the accretion of larger objects like Moon and terrestrial planets generally involves giant impacts, with both the target and projectile probably being differentiated. Then, use of the Hf-W system assumes metal-silicate re-equilibration at high T and P while metal droplets rain through the magma ocean of a growing planet. Currently no experimental data at such conditions exist. Here we report the first results of experiments aimed at studying partitioning of Fe and Ni (proxy for W) between metal and silicate melt formed at high P and T by laser shocks of powered mixtures of pure Fe metal and Ni-bearing ALM-2 dunite. The initial targets with variable metal/dunite ratios were lightly pressed into 6.3 mm pellets (1-3 mm thick) and subjected to single laser pulses (~120-600 J, ~1 nsec). The details of experiments are described in the accompanying abstract by Remo et al. Some shots produced ~ 1 mm round craters in partially preserved targets which have been studied by optical microscopy, SEM and EPMA. The craters have rather rough surfaces and blackened appearance. The SEM images show thin (1-3 microns) films or pockets (3-8 microns) of silicate melt with or without tiny metal blebs which weld together angular grains of olivine and metal. The olivine contains no Al2O3 and ~0.4 wt% NiO; the metal is pure Fe. The melt, besides being lighter in the BSE images, shows distinct compositional differences (higher Al2O3 and FeO, lower MgO and SiO2) from olivine. The NiO content in metal-free melt films and pockets is similar to that in the host olivine. Metal in the metal-bearing melt pockets typically contains 0.2-0.7 wt% Ni and 0.6-1.5 wt% Si, while the NiO content in the silicate melt is close or below the EPMA detection limit of ~0.05 wt%. Thus, our results provide clear evidence for rapid extraction of Ni from silicate melt into metal on a timescale of microseconds. Chemical analyses and further experimental details will be reported at the meeting.

Petaev, M. I.; Jacobsen, S. B.; Remo, J. L.; Adams, R. G.; Sasselov, D. D.

2006-12-01

258

Numerical predictions and experimental results of a dry bay fire environment.  

SciTech Connect

The primary objective of the Safety and Survivability of Aircraft Initiative is to improve the safety and survivability of systems by using validated computational models to predict the hazard posed by a fire. To meet this need, computational model predictions and experimental data have been obtained to provide insight into the thermal environment inside an aircraft dry bay. The calculations were performed using the Vulcan fire code, and the experiments were completed using a specially designed full-scale fixture. The focus of this report is to present comparisons of the Vulcan results with experimental data for a selected test scenario and to assess the capability of the Vulcan fire field model to accurately predict dry bay fire scenarios. Also included is an assessment of the sensitivity of the fire model predictions to boundary condition distribution and grid resolution. To facilitate the comparison with experimental results, a brief description of the dry bay fire test fixture and a detailed specification of the geometry and boundary conditions are included. Overall, the Vulcan fire field model has shown the capability to predict the thermal hazard posed by a sustained pool fire within a dry bay compartment of an aircraft; although, more extensive experimental data and rigorous comparison are required for model validation.

Suo-Anttila, Jill Marie; Gill, Walter; Black, Amalia Rebecca

2003-11-01

259

Experimental comparison of 241Am-Be neutron fluence energy distributions.  

PubMed

(241)Am-Be(alpha,n) neutron sources provide one of the most commonly used neutron fields for routine calibration of neutron sensitive devices. The neutron energy distribution of the IRSN standard (241)Am-Be source was measured in the energy region above 1.65 MeV using a BC501A proton-recoil liquid scintillator. The experimental data were compared to the ISO-recommended neutron energy distribution for an (241)Am-Be source. Some differences in shape were observed, with large variations mainly within the energy interval 3-6 MeV and around 8 MeV. Within the framework of a collaboration between three national metrological institutes (PTB, Germany; NPL, UK and LNE-IRSN, France), the neutron energy distributions of (241)Am-Be sources at each laboratory have been compared. The IRSN-BC501A proton-recoil scintillator was used to measure all the sources. The results show different energy distributions a priori influenced by the origin of the source, i.e. the manufacturing process. The maximum deviation observed for the integral dose equivalent, in the measured BC501A energy range, is within the 4% uncertainty recommended by ISO standard 8529-2 to allow for variations of the neutron spectrum among different (241)Am-Be sources. However, knowledge of the energy distribution of an (241)Am-Be source provides a way to reduce the uncertainty in the dose equivalent rate delivered by such a source. PMID:17510201

Lebreton, L; Zimbal, A; Thomas, D

2007-01-01

260

Numerical and experimental results for focusing of three-dimensional electromagnetic waves into uniaxial crystals.  

PubMed

We present experimental results for focusing of a three-dimensional electromagnetic wave through a plane interface into two different uniaxial crystals, a positive MgF2 crystal and a negative LiNbO3 crystal. These results are compared with numerical results and good agreement is found, both for intensity distributions in various receiving planes and for the locations of the sagittal and tangential focal planes. The theory is briefly outlined both for the exact solution, which includes extraparaxial geometries and double refraction, and for the paraxial solution, in which double refraction is ignored. PMID:19252667

Jain, Momodou; Lotsberg, Jon Kåre; Stamnes, Jakob J; Frette, Øyvind; Velauthapillai, Dhayalan; Jiang, Daya; Zhao, Xiaohong

2009-03-01

261

Modeling the Fracturing of Rock by Fluid Injection - Comparison of Numerical and Experimental Results  

NASA Astrophysics Data System (ADS)

Fluid-rock interactions are mechanically fundamental to many earth processes, including fault zones and hydrothermal/volcanic systems, and to future green energy solutions such as enhanced geothermal systems and carbon capture and storage (CCS). Modeling these processes is challenging because of the strong coupling between rock fracture evolution and the consequent large changes in the hydraulic properties of the system. In this talk, we present results of a numerical model that includes poro-elastic plastic rheology (with hardening, softening, and damage), and coupled to a non-linear diffusion model for fluid pressure propagation and two-phase fluid flow. Our plane strain model is based on the poro- elastic plastic behavior of porous rock and is advanced with hardening, softening and damage using the Mohr- Coulomb failure criteria. The effective stress model of Biot (1944) is used for coupling the pore pressure and the rock behavior. Frictional hardening and cohesion softening are introduced following Vermeer and de Borst (1984) with the angle of internal friction and the cohesion as functions of the principal strain rates. The scalar damage coefficient is assumed to be a linear function of the hardening parameter. Fluid injection is modeled as a two phase mixture of water and air using the Richards equation. The theoretical model is solved using finite differences on a staggered grid. The model is benchmarked with experiments on the laboratory scale in which fluid is injected from below in a critically-stressed, dry sandstone (Stanchits et al. 2011). We simulate three experiments, a) the failure a dry specimen due to biaxial compressive loading, b) the propagation a of low pressure fluid front induced from the bottom in a critically stressed specimen, and c) the failure of a critically stressed specimen due to a high pressure fluid intrusion. Comparison of model results with the fluid injection experiments shows that the model captures most of the experimental observations, including fracture evolution, excellent agreement of the entire load-unload stress strain behavior, and applicable to both drained and un-drained conditions. Bibliography: M.A. Biot. General Theory of Three- Dimensional Consolidation. Journal of Applied Physics, 12:155 - 164, February 1941. P.A. Vermeer and R. de Borst. Non- associated Plasticity For Soils, Concrete and Rock. Heron, 29(37), 1984. S. Stanchits, S. Mayr, S. Shapiro and G. Dresen. Fracturing of Porous Rock Induced by Fluid Injection. Tectonophysics, (503):129-145, 2011.

Heinze, Thomas; Galvan, Boris; Miller, Stephen

2013-04-01

262

Ocean thermal energy conversion plants : experimental and analytical study of mixing and recirculation  

E-print Network

Ocean thermal energy conversion (OTEC) is a method of generating power using the vertical temperature gradient of the tropical ocean as an energy source. Experimental and analytical studies have been carried out to determine ...

Jirka, Gerhard H.

263

Parallel Path Magnet Motor: Development of the Theoretical Model and Analysis of Experimental Results  

NASA Astrophysics Data System (ADS)

Analytical and numerical modelling is performed for the linear actuator of a parallel path magnet motor. In the model based on finite-element analysis, the 3D problem is reduced to a 2D problem, which is sufficiently precise in a design aspect and allows modelling the principle of a parallel path motor. The paper also describes a relevant numerical model and gives comparison with experimental results. The numerical model includes all geometrical and physical characteristics of the motor components. The magnetic flux density and magnetic force are simulated using FEMM 4.2 software. An experimental model has also been developed and verified for the core of switchable magnetic flux linear actuator and motor. The results of experiments are compared with those of theoretical/analytical and numerical modelling.

Dirba, I.; Kleperis, J.

2011-01-01

264

Experimental and analytical, transonic aerodynamic and acoustic results for rectangular and swept rotor blade tips  

NASA Astrophysics Data System (ADS)

This paper presents some experimental and theoretical studies dealing with both acoustics and aerodynamics of helicopter rotor blades in high-speed forward flight. Experimental results in S2Ch acoustically treated wind tunnel concern a comparison between a rectangular blade tip and a parabolic sweptback one, with an anhedral effect, named PF1. They show an increase in aerodynamic performances for the PF1 blades, which is due to a decrease of the transonic flow intensity on the advancing blade side. These results are confirmed by calculation with a transonic small disturbance code. Acoustic measurements show a noise reduction for the PF1 blades. This tendency appears also through calculation. An analytical study evaluates the influence of blade tip shape on the generated thickness noise. Assessment of compressibility effects by quadrupolar noise calculations for several blade tips is presented; the limitations of the use of the Lighthill's acoustic analogy are discussed.

Prieur, J.; Lafon, P.; Caplot, M.; Desopper, A.

265

REFLECTIONS ON MY CONTRIBUTIONS TO PARTICLE PHYSICS AND RECENT EXPERIMENTAL RESULTS FROM RHIC.  

SciTech Connect

My talk today will be composed of two parts. The first part will consist of a summary of some of my experimental contributions over the years. It will not be exhaustive but will highlight the findings that had relevance to the progress of our understanding of particle physics as it has evolved over the years. This section will be divided into three periods: Early, Intermediate and Late, with an in depth discussion of a few of the more significant results. The second part will consist of a discussion of the recently completed Relativistic Heavy Ion Collider (RHIC) machine at Brookhaven National Laboratory (BNL). This will encompass the parameters of the accelerator and some of the interesting and exciting early experimental results emanating from this machine.

SAMIOS,N.P.

2002-01-18

266

Controls-structures interaction guest investigator program: Overview and phase 1 experimental results and future plans  

NASA Technical Reports Server (NTRS)

The NASA Controls-Structures Interaction (CSI) Guest Investigator program is described in terms of its support of the development of CSI technologies. The program is based on the introduction of CSI researchers from industry and academia to available test facilities for experimental validation of technologies and methods. Phase 1 experimental results are reviewed with attention given to their use of the Mini-MAST test facility and the facility for the Advance Control Evaluation of Structures. Experiments were conducted regarding the following topics: collocated/noncollocated controllers, nonlinear math modeling, controller design, passive/active suspension systems design, and system identification and fault isolation. The results demonstrate that significantly enhanced performance from the control techniques can be achieved by integrating knowledge of the structural dynamics under consideration into the approaches.

Smith-Taylor, Rudeen; Tanner, Sharon E.

1993-01-01

267

Rheometry of a dacitic melt: Experimental results and tests of empirical models for viscosity estimation  

SciTech Connect

This paper reports on experimental measurements of the viscosity of a dacitic melt, by means of the technique of of concentric cylinder rheometry. The measurements were done in a temperature range of 1000 to 1150[degrees]C, and at different shear rates. The results were compared with empirical models which are commonly used to estimate the viscosity of single-phase melts of silicates. This data is of great use to the study of magma transport.

Stein, D.J.; Spera, F.J. (Univ. of California, Santa Barbara, CA (United States))

1993-09-15

268

Two Coupled Superconducting Cavities as a Gravitational Wave Detector: First Experimental Results  

E-print Network

First experimental results of a feasibility study of a gravitational wave detector based on two coupled superconducting cavities are presented. Basic physical principles underlying the detector behaviour and sensitivity limits are discussed. The detector layout is described in detail and its rf properties are showed. The limit sensitivity to small harmonic displacements at the detection frequency (around 1 MHz) is showed. The system performance as a potential g.w. detector is discussed and future developments are foreseen.

Ph. Bernard; G. Gemme; R. Parodi; E. Picasso

1999-11-08

269

Electro-Optic Sampling at the TESLA Test Accelerator: Experimental Setup and First Results  

Microsoft Academic Search

Abstract A mode-locked titanium-sapphire laser with 15 fs pulse width is used to determine the temporal profile of the ultrashort electron bunches in the linear TESLA Test accelerator. The experimental setup is described and first results are presented on the synchronization of the Ti:Sa laser with the radio frequency of the superconducting accelerator and on the coincidence measurements between the

M. Brunken; H. Genz; P. Gottlicher; C. Hessler; M. Huning; H. Loos; A. Richter; H. Schlarb; P. Schmuser; S. Simrock; D. Suetterlin; M. Tonutti; D. Turke; Physikalisches Insitut Iiia; Rwth Aachen

270

FIRST EXPERIMENTAL RESULTS FROM DEGAS, THE QUANTUM LIMITED BRIGHTNESS ELECTRON SOURCE  

SciTech Connect

The construction of DEGAS (DEGenerate Advanced Source), a proof of principle for a quantum limited brightness electron source, has been completed at the Lawrence Berkeley National Laboratory. The commissioning and the characterization of this source, designed to generate coherent single electron 'bunches' with brightness approaching the quantum limit at a repetition rate of few MHz, has been started. In this paper the first experimental results are described.

Zolotorev, Max S.; Commins, Eugene D.; Oneill, James; Sannibale, Fernando; Tremsin, Anton; Wan, Weishi

2008-06-23

271

An Experimental Evaluation of Duct-Mounted Relative Humidity Sensors: Part 2 – Accuracy Results  

E-print Network

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. An Experimental Evaluation of Duct-Mounted Relative Humidity Sensors: Part 2-Accuracy Results Joshi, Shailesh N;House, John M;Pate, Michael B...;Klaassen, Curtis J;Nelson, Ron M ASHRAE Transactions; 2005; 111, ProQuest pg. 167 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction...

Joshi, S.N.; Pate, M.B.; Nelson, R.M; House, J.H.; Klaasen, C.J.

272

Helium vapor-cooled brass current leads: experimental and analytical results  

Microsoft Academic Search

This paper presents experimental and analytical results of a pair of helium vapor-cooled brass leads having a rated current, It, of 40 A, operated continuously below, at, and above 40 A. In Regime 1 (0

Haigun Lee; Paul Arakawa; Kenneth R. Efferson; Yukikazu Iwasa

2001-01-01

273

CIGS Solar Cell on Flexible Stainless Steel Substrate Fabricated by Sputtering Method: Simulation and Experimental Results  

E-print Network

-734-615-2843 * E-mail: kanicki@eecs.umich.edu 1 NuvoSun, San Jose, CA95131, U.S.A. We reported on opto and Experimental Results Rui Zhang, Dennis R. Hollars1 and Jerzy Kanicki* Dept. ofElectrical Engineering:ZnO/i-ZnO/CdS/Cu(InGa)Se2 (CIGS)/Mo solar cell using software APSYS. The APSYS simulator is a general

Kanicki, Jerzy

274

Experimental Results from Physical Model of Bidirectional Power Flow Regulator for Power Substations of Electrical Transport  

NASA Astrophysics Data System (ADS)

This article is about model of bidirectional power flow regulator for power substations of electrical transport. The paper presents an experimental model which is made in the laboratory of Power and electrical engineering of Riga Technical University. Also principal block scheme and principal schemes of that model are presented in the form of computer modeling as well as some main results of experiments are presented in the form of diagrams.

Vitols, Aigars; Rankis, Ivars

2009-01-01

275

Columbus meteoroid/debris protection study - Experimental simulation techniques and results  

NASA Astrophysics Data System (ADS)

The methods and measurement techniques used in experimental simulations of micrometeoroid and space debris impacts with the ESA's laboratory module Columbus are described. Experiments were carried out at the two-stage light gas gun acceleration facilities of the Ernst-Mach Institute. Results are presented on simulations of normal impacts on bumper systems, oblique impacts on dual bumper systems, impacts into cooled targets, impacts into pressurized targets, and planar impacts of low-density projectiles.

Schneider, E.; Kitta, K.; Stilp, A.; Lambert, M.; Reimerdes, H. G.

1992-08-01

276

Dielectric properties of crystals with rutile structure. II. Experimental results (neutron-Raman) and model discussion  

Microsoft Academic Search

To carry out a study of the lattice dynamics of a crystal with a rather complex structure (MgF2) a whole set of complementary experimental results and, particularly, absolute measurements of first-order Raman polarisabilities have been obtained. Applying a convenient phenomenological model (shell model) to the case of MgF2 a quite satisfactory description of the strictly dynamical properties (eigenvalues of the

R. Almairac; J. L. Sauvajol; C. Benoit; A. M. Bon

1978-01-01

277

Histopathology of experimental myiasis in mice as a result of infestation and experimental implantation of Dermatobia hominis larvae.  

PubMed

A laboratory model of myiasis as a result of Dermatobia hominis (L.) larvae was developed using mice as hosts. Mice in three groups were each infested with one newly hatched larva and skin biopsies processed for histopathology at 4, 12, and 20 d postinfestation (dpi). Mice in three other groups were each subjected to implantation of one larva collected from an infested (donor) mouse at 4, 12, and 20 dpi. Skin lesions of these receptor mice were then assessed at 10, 14, and 6 d postimplantation (dpimp), respectively. The inflammatory process in infested mice at 4 dpi was discrete, consisting of a thin necrotic layer around the larva, edema, many neutrophils, few eosinophils, mast cells, and proliferation of fibroblasts. At 12 dpi, there was a thicker necrotic layer, edema, many neutrophils and eosinophils, few mast cells, neoformation of capillaries, proliferation of the endothelium and fibroblasts, and early stages of fibrosis. These histopathological characteristics together with fibrosis were observed over a large area of the lesion at 20 dpi. Mice submitted to larval implantations demonstrated similar skin histopathology to that seen in the infested rodents, 10 dpimp corresponding to 12 dpi and 6 or 14 dpimp to 20 dpi. In all mice, the progressive acute inflammatory process followed a sequence linked to factors such as size of larvae and presence of secretory-excretory products. Both infested mice and those implanted experimentally with D. hominis larvae were shown to be suitable models for the study of the parasite-host relationship in this important zoonotic myiasis. PMID:21661330

Leite, A C R; Nascimento, M F A; Leite, L H R; Leite, V H R

2011-05-01

278

Estimating the hyperfine coupling parameters of the avian compass by comprehensively considering the available experimental results  

NASA Astrophysics Data System (ADS)

Migratory birds can utilize the geomagnetic field for orientation and navigation through a widely accepted radical-pair mechanism. Although many theoretical works have been done, the available experimental results have not been fully considered, especially the temporary disorientation induced by the field which is increased by 30% of the geomagnetic field and the disorientation of the very weak resonant field of 15 nT. In this paper, we consider the monotonicity of the singlet yield angular profile as the prerequisite of direction sensitivity, and find that for some optimal values of the hyperfine coupling parameters (that is, the order of 10-7˜10-6 meV) the experimental results available so far can be satisfied. We also investigate the effects of two decoherence environments and demonstrate that, in order to satisfy the available experimental results, the decoherence rate should be lower than the recombination rate. Finally, we investigate the effects of the fluctuating magnetic noises and find that the vertical noise destroys the monotonicity of the profile completely, but the parallel noise preserves the monotonicity perfectly and even can enhance the direction sensitivity.

Xu, Bao-Ming; Zou, Jian; Li, Jun-Gang; Shao, Bin

2013-09-01

279

Estimating the hyperfine coupling parameters of the avian compass by comprehensively considering the available experimental results.  

PubMed

Migratory birds can utilize the geomagnetic field for orientation and navigation through a widely accepted radical-pair mechanism. Although many theoretical works have been done, the available experimental results have not been fully considered, especially the temporary disorientation induced by the field which is increased by 30% of the geomagnetic field and the disorientation of the very weak resonant field of 15 nT. In this paper, we consider the monotonicity of the singlet yield angular profile as the prerequisite of direction sensitivity, and find that for some optimal values of the hyperfine coupling parameters (that is, the order of 10^{-7}?10^{-6} meV) the experimental results available so far can be satisfied. We also investigate the effects of two decoherence environments and demonstrate that, in order to satisfy the available experimental results, the decoherence rate should be lower than the recombination rate. Finally, we investigate the effects of the fluctuating magnetic noises and find that the vertical noise destroys the monotonicity of the profile completely, but the parallel noise preserves the monotonicity perfectly and even can enhance the direction sensitivity. PMID:24125290

Xu, Bao-Ming; Zou, Jian; Li, Jun-Gang; Shao, Bin

2013-09-01

280

First experimentally determined thermodynamic values of francium: hydration energy, energy of partitioning, and thermodynamic radius.  

PubMed

The Gibbs energy of partitioning of Fr(+) ion between water and nitrobenzene has been determined to be 14.5 ± 0.6 kJ/mol at 25 °C, the first ever Gibbs energy of partitioning for francium in particular and the first ever solution thermodynamic quantity for francium in general. This value enabled the ionic radius and standard Gibbs energy of hydration for Fr(+) to be estimated as 173 pm and -251 kJ/mol, respectively, the former value being significantly smaller than previously thought. A new experimental method was established using a cesium dicarbollide as a cation-exchange agent, overcoming problems inherent to the trace-level concentrations of francium. The methodology opens the door to the study of the partitioning behavior of francium to other water-immiscible solvents and the determination of complexation constants for francium binding by receptor molecules. PMID:23848436

Delmau, Lætitia H; Moine, Jérôme; Mirzadeh, Saed; Moyer, Bruce A

2013-08-01

281

Experimental and husbandry procedures as potential modifiers of the results of phenotyping tests  

PubMed Central

To maximize the sensitivity of detecting affects of genetic variants in mice, variables have been minimized through the use of inbred mouse lines, by eliminating infectious organisms and controlling environmental variables. However, the impact of standard animal husbandry and experimental procedures on the validity of experimental data is under appreciated. In this study we monitored the impact of these procedures by using parameters that reflect stress and physiological responses to it. Short-term measures included telemetered heart rate and systolic arterial pressure, core body temperature and blood glucose, while longer-term parameters were assessed such as body weight. Male and female C57BL6/NTac mice were subjected to a range of stressors with different perceived severities ranging from repeated blood glucose and core temperature measurement procedures, intra-peritoneal injection and overnight fasting to cage transport and cage changing. Our studies reveal that common husbandry and experimental procedures significantly influence mouse physiology and behaviour. Systolic arterial pressure, heart rate, locomotor activity, core temperature and blood glucose were elevated in response to a range of experimental procedures. Differences between sexes were evident, female mice displayed more sustained cardiovascular responses and locomotor activity than male mice. These results have important implications for the design and implementation of multiple component experiments where the lasting effects of stress from previous tests may modify the outcomes of subsequent ones. PMID:22713295

Gerdin, Anna-Karin; Igosheva, Natalia; Roberson, Laura-Anne; Ismail, Ozama; Karp, Natasha; Sanderson, Mark; Cambridge, Emma; Shannon, Carl; Sunter, David; Ramirez-Solis, Ramiro; Bussell, James; White, Jacqueline K.

2012-01-01

282

RESEARCH RESULTS FORUM FOR RENEWABLE ENERGY TECHNOLOGY AND RESOURCE ASSESSMENTS  

E-print Network

in 100 kW turbines · New financing options such as PPAs have boosted the market · Utility-scale turbinesRESEARCH RESULTS FORUM FOR RENEWABLE ENERGY TECHNOLOGY AND RESOURCE ASSESSMENTS Public Workshop at the California Energy Commission (CEC) September 3, 2014 California Renewable Energy Center #12;California

California at Davis, University of

283

RESEARCH RESULTS FORUM FOR RENEWABLE ENERGY TECHNOLOGY AND RESOURCE ASSESSMENTS  

E-print Network

Renewable Energy Center Assessment of Geothermal Resources In Under-served Regions #12;California Renewable Energy Center The goal of this task is to develop a methodology for assessing geothermal resourcesRESEARCH RESULTS FORUM FOR RENEWABLE ENERGY TECHNOLOGY AND RESOURCE ASSESSMENTS Public Workshop

California at Davis, University of

284

SMA Numerical Modeling Versus Experimental Results: Parameter Identification and Model Prediction Capabilities  

NASA Astrophysics Data System (ADS)

In this work, we briefly review the one-dimensional version of a well-known phenomenological shape memory alloy (SMA) constitutive model able to represent the main macroscopic SMA macroscopic behaviors (i.e., superelasticity and shape-memory effect). We then show how to identify the needed parameters from experimental results and, in particular, from strain-temperature tests. We finally use the obtained material parameters to test the prediction properties of the model, comparing numerical results with some experiments (different from those used for the identification), and we discuss model capabilities and further required enhancements.

Auricchio, Ferdinando; Coda, Alberto; Reali, Alessandro; Urbano, Marco

2009-08-01

285

The 3D structure of the hadrons: recents results and experimental program at Jefferson Lab  

SciTech Connect

The understanding of Quantum Chromodynamics (QCD) at large distances still remains one of the main outstanding problems of nuclear physics. Studying the internal structure of hadrons provides a way to probe QCD in the non-perturbative domain and can help us unravel the internal structure of the most elementary blocks of matter. Jefferson Lab (JLab) has already delivered results on how elementary quarks and gluons create nucleon structure and properties. The upgrade of JLab to 12 GeV will allow the full exploration of the valence-quark structure of nucleons and the extraction of real threedimensional pictures. I will present recent results and review the future experimental program at JLab.

Munoz Camacho, Carlos [Institut de Physique Nucleaire, Orsay

2014-04-01

286

Measurements of energy distribution in microwave plasmas of N2 and He and comparisons with results for H2  

NASA Technical Reports Server (NTRS)

An electrothermal propulsion concept utilizing a microwave plasma system as the mechanism to convert electromagnetic energy into translational energy of the flowing gas is being investigated. Specifically, this study compares the energy transfer characteristics of three different gases, H2, N2, and He, to gain some insight as to the dominant energy transfer processes present in a microwave plasma. A calorimetric experimental system has been designed and built enclosing the microwave plasma system to accurately determine the net energy transferred to the flowing gas. Results are obtained for N2 and He discharges and compared with previously reported experimental results for H2.

Chapman, R.; Hawley, M. C.

1984-01-01

287

Comparison of numerical and experimental results of the flow in the U9 Kaplan turbine model  

NASA Astrophysics Data System (ADS)

The present work compares simulations made using the OpenFOAM CFD code with experimental measurements of the flow in the U9 Kaplan turbine model. Comparisons of the velocity profiles in the spiral casing and in the draft tube are presented. The U9 Kaplan turbine prototype located in Porjus and its model, located in Älvkarleby, Sweden, have curved inlet pipes that lead the flow to the spiral casing. Nowadays, this curved pipe and its effect on the flow in the turbine is not taken into account when numerical simulations are performed at design stage. To study the impact of the inlet pipe curvature on the flow in the turbine, and to get a better overview of the flow of the whole system, measurements were made on the 1:3.1 model of the U9 turbine. Previously published measurements were taken at the inlet of the spiral casing and just before the guide vanes, using the laser Doppler anemometry (LDA) technique. In the draft tube, a number of velocity profiles were measured using the LDA techniques. The present work extends the experimental investigation with a horizontal section at the inlet of the draft tube. The experimental results are used to specify the inlet boundary condition for the numerical simulations in the draft tube, and to validate the computational results in both the spiral casing and the draft tube. The numerical simulations were realized using the standard k-e model and a block-structured hexahedral wall function mesh.

Petit, O.; Mulu, B.; Nilsson, H.; Cervantes, M.

2010-08-01

288

Position control of a single-link mechanism activated by shape memory alloy springs: experimental results  

NASA Astrophysics Data System (ADS)

This research involves the application of methods to actively control the vibration of a plate-like structure with discontinuous boundary conditions. The research is motivated by the need to control vibrations on rack shelves in use on the International Space Station (ISS). Vibration of the rack shelves can adversely affect experiments being performed on those shelves. In this work, control of a rack shelf similar to those in use on the ISS is examined. Piezoelectric actuators bonded to the shelf structure are proposed as a method for controlling rack shelf vibrations. A two-dimensional asymmetric piezoelectric actuator model is first developed. The Ritz expansion method is then employed to derive the equations of motion for the combined piezoelectric actuators and rack shelf system with discontinuous boundary conditions. Model parameters from the analytical solution are used in conjunction with experimentally obtained parameters to develop a control model for the active structure. The control model is then used, together with a linear quadratic approach, to develop two different control strategies: collocated output feedback control and modal control. Results from an experimental evaluation of the two control approaches are presented. Based on the experimental results, the two control strategies are shown to be effective in controlling the first several modes of the rack shelf system at frequencies below 800 Hz. Portions of this work were presented in 'Active Control of International Space Station Experiment Rack Shelf Simulator Vibrations', Proceedings of 2004 ASME International Mechanical Engineering Congress, Anaheim, California, November 2004 (IMECE2004-60853).

Wang, Jingdou; Shepard, W. Steve, Jr.; Williams, Keith A.; Gattis, Christy B.

2006-02-01

289

Experimental Results of NWCF Run H4 Calcine Dissolution Studies Performed in FY-98 and -99  

SciTech Connect

Dissolution experiments were performed on actual samples of NWCF Run H-4 radioactive calcine in fiscal years 1998 and 1999. Run H-4 is an aluminum/sodium blend calcine. Typical dissolution data indicates that between 90-95 wt% of H-4 calcine can be dissolved using 1gram of calcine per 10 mLs of 5-8M nitric acid at boiling temperature. Two liquid raffinate solutions composed of a WM-188/aluminum nitrate blend and a WM-185/aluminum nitrate blend were converted into calcine at the NWCF. Calcine made from each blend was collected and transferred to RAL for dissolution studies. The WM-188/aluminum nitrate blend calcine was dissolved with resultant solutions used as feed material for separation treatment experimentation. The WM-185/aluminum nitrate blend calcine dissolution testing was performed to determine compositional analyses of the dissolved solution and generate UDS for solid/liquid separation experiments. Analytical fusion techniques were then used to determine compositions of the solid calcine and UDS from dissolution. The results from each of these analyses were used to calculate elemental material balances around the dissolution process, validating the experimental data. This report contains all experimental data from dissolution experiments performed using both calcine blends.

Garn, Troy Gerry; Herbst, Ronald Scott; Batcheller, Thomas Aquinas; Sierra, Tracy Laureena

2001-08-01

290

Wind Code Application to External Forebody Flowfields with Comparisons to Experimental Results  

NASA Technical Reports Server (NTRS)

The WIND Code, a general purpose Navier-Stokes solver, has been utilized to obtain supersonic external flowfield Computational Fluid Dynamics (CFD) solutions over an axisymmetric, parabolic forebody with comparisons made to wind tunnel experimental results. Various cases have been investigated at supersonic freestream conditions ranging from Mach 2.0 to 3.5, at 0 deg and 3 deg angles-of-attack, and with either a sharp-nose or blunt-nose forebody configuration. Both a turbulent (Baldwin-Lomax algebraic turbulence model) and a laminar model have been implemented in the CFD. Obtaining the solutions involved utilizing either the parabolized- or full-Navier-Stokes analyses supplied in WIND. Comparisons have been made with static pressure measurements, with boundary-layer rake and flowfield rake pitot pressure measurements, and with temperature sensitive paint experimental results. Using WIND's parabolized Navier-Stokes capability, grid sequencing, and the Baldwin-Lomax algebraic turbulence model allowed for significant reductions in computational time while still providing good agreement with experiment. Given that CFD and experiment compare well, WIND is found to be a good computational platform for solving this type of forebody problem, and the grids developed in conjunction with it will be used in the future to investigate varying freestream conditions not tested experimentally.

Frate, F. C.; Kim, H. D.

2001-01-01

291

Experimental Studies of Energy Trends Development of Artificial Ecosystems and Their Links  

NASA Astrophysics Data System (ADS)

Two types of artificial ecosystems with different trophic links have been used for experimental studies of energy trends development and microevolution procecces 1 Microbial populations in artificial ecosystems AES for water purification are the most active transforming organisms and consumers of organic substances of wastes In our experiments we observed different changes in Active Sludge AS structure and populations composition connected with changes in environmental factors and self-development of AS As a result of biological adaptations unutilized substrate concentration decreased in many cases The exact structure of microbial community also changed the biological diversity decreased But in all experiments we observed certain increase of fluxes of energy utilized by the system 2 In experiments with continuous microbial cultures we used Escherichia coli genetically engineered strains They contain in plasmids the cloned genes of marine photobacteria bioluminescence and genes of green fluorescent protein GFP which expression level can be easily changed and controlled We observed kinetic diversity of evolutionary transfers in systems But general mechanisms characterized the increase of used energy flow by bacterial populations under study According to our experimental data at spontaneous development and microevolution processes heat dissipation characterizing the rate of entropy growth increased rather then decreased or maintained steady as G Nikolis and I Prigogin believed The results require further development

Somova, L. A.; Pechurkin, N. S.; Brilkov, A. V.; Loginov, I. A.; Morozova, E. V.

292

Artificial cochlea and acoustic black hole travelling waves observation: Model and experimental results  

NASA Astrophysics Data System (ADS)

An inhomogeneous fluid structure waveguide reproducing passive behaviour of the inner ear is modelled with the help of the Wentzel-Kramers-Brillouin method. A physical setup is designed and built. Experimental results are compared with a good correlation to theoretical ones. The experimental setup is a varying width plate immersed in fluid and terminated with an acoustic black hole. The varying width plate provides a spatial repartition of the vibration depending on the excitation frequency. The acoustic black hole is made by decreasing the plate's thickness with a quadratic profile and by covering this region with a thin film of viscoelastic material. Such a termination attenuates the flexural wave reflection at the end of the waveguide, turning standing waves into travelling waves.

Foucaud, Simon; Michon, Guilhem; Gourinat, Yves; Pelat, Adrien; Gautier, François

2014-07-01

293

Shuttle Return To Flight Experimental Results: Cavity Effects on Boundary Layer Transition  

NASA Technical Reports Server (NTRS)

The effect of an isolated rectangular cavity on hypersonic boundary layer transition of the windward surface of the Shuttle Orbiter has been experimentally examined in the Langley Aerothermodynamics Laboratory in support of an agency-wide effort to prepare the Shuttle Orbiter for return to flight. This experimental study was initiated to provide a cavity effects database for developing hypersonic transition criteria to support on-orbit decisions to repair a damaged thermal protection system. Boundary layer transition results were obtained using 0.0075-scale Orbiter models with simulated tile damage (rectangular cavities) of varying length, width, and depth. The database contained within this report will be used to formulate cavity-induced transition correlations using predicted boundary layer edge parameters.

Liechty, Derek S.; Horvath, Thomas J.; Berry, Scott A.

2006-01-01

294

Shuttle Return To Flight Experimental Results: Protuberance Effects on Boundary Layer Transition  

NASA Technical Reports Server (NTRS)

The effect of isolated roughness elements on the windward boundary layer of the Shuttle Orbiter has been experimentally examined in the Langley Aerothermodynamic Laboratory in support of an agency-wide effort to prepare the Shuttle Orbiter for return to flight. This experimental effort was initiated to provide a roughness effects database for developing transition criteria to support on-orbit decisions to repair damage to the thermal protection system. Boundary layer transition results were obtained using trips of varying heights and locations along the centerline and attachment lines of 0.0075-scale models. Global heat transfer images using phosphor thermography of the Orbiter windward surface and the corresponding heating distributions were used to infer the state of the boundary layer (laminar, transitional, or turbulent). The database contained within this report will be used to formulate protuberance-induced transition correlations using predicted boundary layer edge parameters.

Liechty, Derek S.; Berry, Scott A.; Horvath, Thomas J.

2006-01-01

295

Supersonic Retropropulsion Experimental Results from the NASA Ames 9- x 7-Foot Supersonic Wind Tunnel  

NASA Technical Reports Server (NTRS)

Supersonic retropropulsion was experimentally examined in the Ames Research Center 9x7-Foot Supersonic Wind Tunnel at Mach 1.8 and 2.4. The experimental model, previously designed for and tested in the Langley Research Center Unitary Plan Wind Tunnel at Mach 2.4, 3.5 and 4.6, was a 5-in diameter 70-deg sphere-cone forebody with a 9.55-in long cylindrical aftbody. The forebody was designed to accommodate up to four 4:1 area ratio nozzles, one on the model centerline and the other three on the half radius spaced 120-deg apart. Surface pressure and flow visualization were the primary measurements, including high-speed data to investigate the dynamics of the interactions between the bow and nozzle shocks. Three blowing configurations were tested with thrust coefficients up to 10 and angles of attack up to 20-deg. Preliminary results and observations from the test are provided

Berry, Scott A.; Rhode, Matthew N.; Edquist, Karl T.

2012-01-01

296

Experimental Studies on Kaonic Atoms at DA{phi}NE: Recent Results and Perspectives  

SciTech Connect

The DEAR (DA{phi}NE Exotic Atom Research) experiment and the successor SIDDHARTA (Silicon Drift Detectors for Hadronic Atom Research by Timing Application) are using precision X-ray spectroscopy of kaonic hydrogen atoms to determine the strong interaction induced shift and width of the ground state. From the kaonic hydrogen and kaonic deuterium shifts and widths the isospin-dependent antikaon-nucleon scattering lengths can be determined, thus contributing to the understanding of chiral symmetry breaking in the strangeness sector.The experimental method of the DEAR experiment and the final results of the kaonic atom studies are presented, i.e. the first measurement of three X-ray transitions of kaonic nitrogen and the most precise measurement of the strong interaction caused shift and width in kaonic hydrogen obtained up to now.An outlook to the next steps of the experimental program will be given.

Marton, Johann [Stefan Meyer Institute, Austrian Academy of Sciences, Boltzmanngasse 3, 1090 Vienna (Austria)

2006-07-11

297

Comparison between maximum radial expansion of ultrasound contrast agents and experimental postexcitation signal results  

PubMed Central

Experimental postexcitation signal data of collapsing Definity microbubbles are compared with the Marmottant theoretical model for large amplitude oscillations of ultrasound contrast agents (UCAs). After taking into account the insonifying pulse characteristics and size distribution of the population of UCAs, a good comparison between simulated results and previously measured experimental data is obtained by determining a threshold maximum radial expansion (Rmax) to indicate the onset of postexcitation. This threshold Rmax is found to range from 3.4 to 8.0 times the initial bubble radius, R0, depending on insonification frequency. These values are well above the typical free bubble inertial cavitation threshold commonly chosen at 2R0. The close agreement between the experiment and models suggests that lipid-shelled UCAs behave as unshelled bubbles during most of a large amplitude cavitation cycle, as proposed in the Marmottant equation. PMID:21302993

King, Daniel A.; O’Brien, William D.

2011-01-01

298

LBE water interaction in sub-critical reactors: First experimental and modelling results  

NASA Astrophysics Data System (ADS)

This paper concerns the study of the phenomena involved in the interaction between LBE and pressurised water which could occur in some hypothetical accidents in accelerator driven system type reactors. The LIFUS 5 facility was designed and built at ENEA-Brasimone to reproduce this kind of interaction in a wide range of conditions. The first test of the experimental program was carried out injecting water at 70 bar and 235 °C in a reaction vessel containing LBE at 1 bar and 350 °C. A pressurisation up to 80 bar was observed in the test section during the considered transient. The SIMMER III code was used to simulate the performed test. The calculated data agree in a satisfactory way with the experimental results giving confidence in the possibility to use this code for safety analyses of heavy liquid metal cooled reactors.

Ciampichetti, A.; Agostini, P.; Benamati, G.; Bandini, G.; Pellini, D.; Forgione, N.; Oriolo, F.; Ambrosini, W.

2008-06-01

299

Use of dynamic theory to describe experimental results from volume holography  

NASA Technical Reports Server (NTRS)

The general applicability of dynamic theory to the description of the recording and readout characteristics of volume (thick) hologram gratings is indicated. In dynamic theory (as opposed to static theory), the volume nature of the thick holographic grating allows the interference of an incident light beam with its own diffracted beam inside the recording medium. This effect causes the continuous recording of another grating that alters the initial one, producing a resultant grating that is not uniform through the thickness of the recording material and a grating whose writing and reading characteristics may vary dramatically, depending on the recording material and the experimental conditions. A large number of diverse types of writing, reading, and angular-selectivity behavior have been reported. The dynamic theory of thick-hologram writing and reading is shown to predict qualitatively all of these various types of experimental behavior.

Magnusson, R.; Gaylord, T. K.

1976-01-01

300

Photoinduced random molecular reorientation by nonradiative energy relaxation: An experimental test  

SciTech Connect

By measuring the time-resolved fluorescence depolarization as a function of light excitation wavelength we address the question of a possible photoinduced orientational randomization of amino-anthraquinone dyes in liquid solutions. We find no significant dependence within the experimental uncertainties of both the initial molecule anisotropy and of the subsequent rotational diffusion dynamics on the photon energy. This indicates that this effect, if present, must be very small. A simple model of photoinduced local heating and corresponding enhanced rotational diffusion is in accordance with this result. This null result rules out some recent proposals that photoinduced local heating may contribute significantly to molecular reorientation effects in different materials. A small but statistically significant effect of photon energy is instead found in the excited-state lifetime of the dye.

Manzo, C.; Paparo, D.; Marrucci, L. [INFM-Coherentia and Universita 'Federico II', Dipartimento di Scienze Fisiche, Complesso di Monte S. Angelo, via Cintia, 80126 Naples (Italy)

2004-11-01

301

Experimental demonstration of high two-photon time-energy entanglement  

SciTech Connect

We report on the experimental demonstration of high energy-time entanglement in two-photon states created in the process of spontaneous parametric down-conversion. We show that the classical variance product, which we violate by three orders of magnitude, actually represents a lower bound estimate of the number of information eigenmodes K. Explicit measurements estimate K to be greater than 100, with theoretical estimates predicting a value of as high as 1x10{sup 6}. These results provide incentive for the practical feasibility of large bandwidth quantum information processing, particularly in cryptography over large distances.

Ali Khan, Irfan; Howell, John C. [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States)

2006-03-15

302

An experimental study of SO3 dissociation as a mechanism for converting and transporting solar energy  

NASA Technical Reports Server (NTRS)

The high temperature catalytic dissocation of SO3 is an important chemical process being considered in the development and application of solar-thermal energy conversion, transport, and storage systems. A facility for evaluating chemical converter-heat exchangers at temperatures to 1000 C with high flow rates of gaseous SO3 feedstock has been assembled and operated on the NMSU campus. Several quartz and metal reactors containing different catalyst configurations have been tested. Descriptions of the test facility and of the reactors are given along with a presentation and discussion of experimental results.

Mccrary, J. H.; Mccrary, G. E.; Chubb, T. A.; Won, Y. S.

1981-01-01

303

OVERVIEW OF RECENT EXPERIMENTAL RESULTS FROM THE DIII-D ADVANCED TOKAMAK PROGRAM  

SciTech Connect

OAK A271 OVERVIEW OF RECENT EXPERIMENTAL RESULTS FROM THE DIII-D ADVANCED TOKAMAK PROGRAM. The DIII-D research program is developing the scientific basis for advanced tokamak (AT) modes of operation in order to enhance the attractiveness of the tokamak as an energy producing system. Since the last International Atomic Energy Agency (IAEA) meeting, they have made significant progress in developing the building blocks needed for AT operation: (1) they have doubled the magnetohydrodynamic (MHD) stable tokamak operating space through rotational stabilization of the resistive wall mode; (2) using this rotational stabilization, they have achieved {beta}{sub N}H{sub 89} {ge} 10 for 4 {tau}{sub E} limited by the neoclassical tearing mode; (3) using real-time feedback of the electron cyclotron current drive (ECCD) location, they have stabilized the (m,n) = (3,2) neoclassical tearing mode and then increased {beta}{sub T} by 60%; (4) they have produced ECCD stabilization of the (2,1) neoclassical tearing mode in initial experiments; (5) they have made the first integrated AT demonstration discharges with current profile control using ECCD; (6) ECCD and electron cyclotron heating (ECH) have been used to control the pressure profile in high performance plasmas; and (7) they have demonstrated stationary tokamak operation for 6.5 s (36 {tau}{sub E}) at the same fusion gain parameter of {beta}{sub N}H{sub 89}/q{sub 95}{sup 2} {approx} 0.4 as ITER but at much higher q{sub 95} = 4.2. The authors have developed general improvements applicable to conventional and advanced tokamak operating modes: (1) they have an existence proof of a mode of tokamak operation, quiescent H-mode, which has no pulsed, ELM heat load to the divertor and which can run for long periods of time (3.8 s or 25 {tau}{sub E}) with constant density and constant radiated power; (2) they have demonstrated real-time disruption detection and mitigation for vertical disruption events using high pressure gas jet injection of noble gases; (3) they have found that the heat and particle fluxes to the inner strike points of balanced, double-null divertors are much smaller than to the outer strike points. They have made detailed investigations of the edge pedestal and SOL: (1) Atomic physics and plasma physics both play significant roles in setting the width of the edge density barrier in H-mode; (2) ELM heat flux conducted to the divertor decreases as density increases; (3) Intermittent, bursty transport contributes to cross field particle transport in the scrape-off layer (SOL) of H-mode and, especially, L-mode plasmas.

BURRELL,HK

2002-11-01

304

Retained gas sampler extractor mixing and mass transfer rate study: Experimental and simulation results  

SciTech Connect

Research staff at Pacific Northwest National Laboratory conducted experimental testing and computer simulations of the impeller-stirred Retained Gas Sampler (RGS) gas extractor system. This work was performed to verify experimentally the effectiveness of the extractor at mixing viscous fluids of both Newtonian and non-Newtonian rheology representative of Hanford single- and double-shell wastes, respectively. Developing the computational models and validating their results by comparing them with experimental results would enable simulations of the mixing process for a range of fluid properties and mixing speeds. Five tests were performed with a full-scale, optically transparent model extractor to provide the data needed to compare mixing times for fluid rheology, mixer rotational direction, and mixing speed variation. The computer model was developed and exercised to simulate the tests. The tests demonstrated that rotational direction of the pitched impeller blades was not as important as fluid rheology in determining mixing time. The Newtonian fluid required at least six hours to mix at the hot cell operating speed of 3 rpm, and the non-Newtonian fluid required at least 46 hours at 3 rpm to become significantly mixed. In the non-Newtonian fluid tests, stagnant regions within the fluid sometimes required days to be fully mixed. Higher-speed (30 rpm) testing showed that the laminar mixing time was correlated to mixing speed. The tests demonstrated that, using the RGS extractor and current procedures, complete mixing of the waste samples in the hot cell should not be expected. The computer simulation of Newtonian fluid mixing gave results comparable to the test while simulation of non-Newtonian fluid mixing would require further development. In light of the laboratory test results, detailed parametric analysis of the mixing process was not performed.

Recknagle, K.P.; Bates, J.M.; Shekarriz, A.

1997-11-01

305

Theoretical and experimental study of the intermediate field dynamics of ocean thermal energy conversion plants  

Microsoft Academic Search

Results are described of a two-year research effort which was conducted with the following objectives: investigate analytically and experimentally the intermediate field spreading in a steady ocean current; investigate analytically and experimentally the transient intermediate field spreading in a stagnant ocean; compare the results with other available data on buoyancy driven currents in stratified surroundings, including the concurrent experimental program

G. H. Jirka; J. M. Jones; F. E. Sargent

1980-01-01

306

Transdermal flux predictions for selected selective oestrogen receptor modulators (SERMs): comparison with experimental results.  

PubMed

The aim of this work was to evaluate the feasibility of delivering transdermally a series of highly lipophilic compounds (log P ~4-7), comprising several selective oestrogen receptor modulators and a modified testosterone (danazol). The maximum fluxes of the drugs were predicted theoretically using the modified Potts & Guy algorithm (to determine the permeability coefficient (kp) from water) and the calculated aqueous solubilities. The correction provided by Cleek & Bunge took into account the contribution of the viable epidermal barrier to the skin permeation of highly lipophilic compounds. Experimental measurements of drug fluxes from saturated hydroalcoholic solutions were determined in vitro through excised pig skin. Overall, the predicted fluxes were in good general agreement (within a factor of 10) with the experimental results. Most of the experimental fluxes were greater than those predicted theoretically suggesting that the 70:30 v/v ethanol-water vehicle employed may have had a modest skin penetration enhancement effect. This investigation shows that the transdermal fluxes of highly lipophilic compounds can be reasonably predicted from first principles provided that the viable epidermis, underlying the stratum corneum, is included as a potentially important contributor to the skin's overall barrier function. Furthermore, the absolute values of the measured fluxes, when considered in parallel with previous clinical studies, indicate that it might be feasible to topically deliver a therapeutically useful amount of some of the compounds considered to treat cancerous breast tissue. PMID:24076520

Güngör, Sevgi; Delgado-Charro, M Begoña; Masini-Etévé, Valérie; Potts, Russell O; Guy, Richard H

2013-12-28

307

Plasma exhaust purification by thermal swing adsorption: Experimental results and modeling  

SciTech Connect

For several years at the Joint Research Centre-Ispra laboratories, cyclic adsorption processes have been developed for the purification of the plasma exhaust stream of a deuterium-tritium fusion reactor. A purification process consisting of two coupled thermal swing adsorption systems seemed to be the most convenient process. In this context, a screening study was carried out to select the most suitable adsorbent materials and appropriate working temperatures. This was mainly done by experimental measurements of adsorption isotherms of the single components of the plasma exhaust stream and by a careful evaluation of the multicomponent adsorption equilibria. Experiments on adsorption dynamics were carried out in a pilot plant to demonstrate the feasibility and to evaluate the performance of the process. The experimental apparatus was designed to treat gas mixture flow rates up to 20 to 30 standard temperature and pressure l/h. A mathematical model was developed and tested against the experimental results to describe the adsorption process and, in particular, to evaluate and to optimize the process cycle time. 27 refs., 4 figs., 9 tabs.

Ricapito, I.; Malara, R.C. [Joint Research Centre-Ispra (Italy)

1996-03-01

308

TRIDENT high-energy-density facility experimental capabilities and diagnostics  

Microsoft Academic Search

The newly upgraded TRIDENT high-energy-density (HED) facility provides high-energy short-pulse laser-matter interactions with powers in excess of 200 TW and energies greater than 120 J. In addition, TRIDENT retains two long-pulse (nanoseconds to microseconds) beams that are available for simultaneous use in either the same experiment or a separate one. The facility's flexibility is enhanced by the presence of two

S. H. Batha; R. Aragonez; F. L. Archuleta; T. N. Archuleta; J. F. Benage; J. A. Cobble; J. S. Cowan; V. E. Fatherley; K. A. Flippo; D. C. Gautier; R. P. Gonzales; S. R. Greenfield; B. M. Hegelich; T. R. Hurry; R. P. Johnson; J. L. Kline; S. A. Letzring; E. N. Loomis; F. E. Lopez; S. N. Luo; D. S. Montgomery; J. A. Oertel; D. L. Paisley; S. M. Reid; P. G. Sanchez; A. Seifter; T. Shimada; J. B. Workman

2008-01-01

309

Shock waves in rapid flows of dense granular materials: theoretical predictions and experimental results.  

PubMed

Strong shocks in rapid dense granular flows are studied theoretically and analyzed in detail to compare with benchmark experimental data. The experimental data includes particle image velocimetry measurements of dry granular flow following its continuous release from a silo. The rapidly moving material down the chute impinges on an obstruction wall erected perpendicular at the end of a long and steep channel. Impact leads to a sudden change in the flow regime from a fast moving supercritical thin layer to a stagnant thick heap with variable thickness. This flow configuration is particularly interesting because it is analogous to some hydraulic and aerodynamic situations. We present results about the depth and the velocity evolution and their comparisons with theoretical predictions associated with frictional granular flow equations incorporating anisotropic pressure conditions. These flow equations are integrated by implementing high-resolution nonoscillatory central differencing total variation diminishing schemes. The dynamical and geometrical effects of the flow will be discussed in detail. These include geometry evolution and depositions at supercritical and subcritical flows, the impact velocity, shock speed, its position and evolution, choice of numerical limiters, and the influence of friction angles on the dynamics and depositions. An excellent agreement between theoretical predictions and experimental observations will be demonstrated. These results can be applied to estimate impact pressures exerted by avalanches on defense structures or infrastructure along the channel and in the run-out zones, and to study the complex flow dynamics around the obstacles and in depositions when the mass comes suddenly to a standstill. Importantly, these results can form a basis for calibration of numerical simulations when strong shocks occur in granular flows. PMID:18999419

Pudasaini, Shiva P; Kröner, Christian

2008-10-01

310

Broadband optical cavities for infrared free electron lasers Analysis and preliminary experimental results  

NASA Astrophysics Data System (ADS)

One advantage of the free electron laser (FEL) is related to its capability for broadband tuning through variation of either the wiggler magnetic field strength or the electronic energy. As in any laser system, broadband optical feedback is needed for the practical attainment of broadband tunability. Cutolo and Madey (1984) have concluded that, in the IR, broadband optical feedback could best be accomplished through the use of metallic mirrors in a stable optical cavity configuration. As a solution to the output coupling problem, it has been proposed to employ an intracavity acoustooptic output coupler. A description has been given of several different possible configurations for the output coupler, and an analysis of thermal effects and effects of finite bandwidth has been conducted. The present investigation has the aim to provide a description of the complete design of the 2-10-micron optical cavity for the Mark III FEL, taking into account the experimental performance of the acoustooptic couplers.

Cutolo, A.; Khuri-Yakub, B. T.; Madey, J. M. J.

1984-09-01

311

Corrosion by liquid lead and lead-bismuth: experimental results review and analysis  

SciTech Connect

Liquid metal technologies for liquid lead and lead-bismuth alloy are under wide investigation and development for advanced nuclear energy systems and waste transmutation systems. Material corrosion is one of the main issues studied a lot recently in the development of the liquid metal technology. This study reviews corrosion by liquid lead and lead bismuth, including the corrosion mechanisms, corrosion inhibitor and the formation of the protective oxide layer. The available experimental data are analyzed by using a corrosion model in which the oxidation and scale removal are coupled. Based on the model, long-term behaviors of steels in liquid lead and lead-bismuth are predictable. This report provides information for the selection of structural materials for typical nuclear reactor coolant systems when selecting liquid lead or lead bismuth as heat transfer media.

Zhang, Jinsuo [Los Alamos National Laboratory

2008-01-01

312

Importance of dose-rate and cell proliferation in the evaluation of biological experimental results  

NASA Technical Reports Server (NTRS)

The nuclei of cells within the bodies of astronauts traveling on extended missions outside the geomagnetosphere will experience single traversals of particles with high Linear Energy Transfer (LET) (e.g., one iron ion per one hundred years, on average) superimposed on a background of tracks with low LET (approximately one proton every two to three days, and one helium ion per month). In addition, some cell populations within the body will be proliferating, thus possibly providing increasing numbers of cells with 'initiated' targets for subsequent radiation hits. These temporal characteristics are not generally reproduced in laboratory experimental protocols. Implications of the differences in the temporal patterns of radiation delivery between conventionally designed radiation biology experiments and the pattern to be experienced in space are examined and the importance of dose-rate and cell proliferation are pointed out in the context of radiation risk assessment on long mission in space.

Curtis, S. B.

1994-01-01

313

Comparison of experimental data with results of some drying models for regularly shaped products  

NASA Astrophysics Data System (ADS)

This paper presents an experimental and theoretical investigation of drying of moist slab, cylinder and spherical products to study dimensionless moisture content distributions and their comparisons. Experimental study includes the measurement of the moisture content distributions of slab and cylindrical carrot, slab and cylindrical pumpkin and spherical blueberry during drying at various temperatures (e.g., 30, 40, 50 and 60°C) at specific constant velocity ( U = 1 m/s) and the relative humidity ? = 30%. In theoretical analysis, two moisture transfer models are used to determine drying process parameters (e.g., drying coefficient and lag factor) and moisture transfer parameters (e.g., moisture diffusivity and moisture transfer coefficient), and to calculate the dimensionless moisture content distributions. The calculated results are then compared with the experimental moisture data. A considerably high agreement is obtained between the calculations and experimental measurements for the cases considered. The effective diffusivity values were evaluated between 0.741 × 10-5 and 5.981 × 10-5 m2/h for slab products, 0.818 × 10-5 and 6.287 × 10-5 m2/h for cylindrical products and 1.213 × 10-7 and 7.589 × 10-7 m2/h spherical products using the Model-I and 0.316 × 10-5-5.072 × 10-5 m2/h for slab products, 0.580 × 10-5-9.587 × 10-5 m2/h for cylindrical products and 1.408 × 10-7-13.913 × 10-7 m2/h spherical products using the Model-II.

Kaya, Ahmet; Ayd?n, Orhan; Dincer, Ibrahim

2010-05-01

314

Theoretical versus experimental results for the rotordynamic coefficients of eccentric, smooth, gas annular seal annular gas seals  

NASA Technical Reports Server (NTRS)

This viewgraph presentation presents the following results: (1) The analytical results overpredict the experimental results for the direct stiffness values and incorrectly predict increasing stiffness with decreasing pressure ratios. (2) Theory correctly predicts increasing cross-coupled stiffness, K(sub YX), with increasing eccentricity and inlet preswirl. (3) Direct damping, C(sub XX), underpredicts the experimental results, but the analytical results do correctly show that damping increases with increasing eccentricity. (4) The whirl frequency values predicted by theory are insensitive to changes in the static eccentricity ratio. Although these values match perfectly with the experimental results at 16,000 rpm, the results at the lower speed do not correspond. (5) Theoretical and experimental mass flow rates match at 5000 rpm, but at 16,000 rpm the theoretical results overpredict the experimental mass flow rates. (6) Theory correctly shows the linear pressure profiles and the associated entrance losses with the specified rotor positions.

Childs, Dara W.; Alexander, Chis

1994-01-01

315

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

NASA Astrophysics Data System (ADS)

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.

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

2010-06-01

316

Investigation of sonar transponders for offshore wind farms: modeling approach, experimental setup, and results.  

PubMed

The installation of offshore wind farms in the German Exclusive Economic Zone requires the deployment of sonar transponders to prevent collisions with submarines. The general requirements for these systems have been previously worked out by the Research Department for Underwater Acoustics and Marine Geophysics of the Bundeswehr. In this article, the major results of the research project "Investigation of Sonar Transponders for Offshore Wind Farms" are presented. For theoretical investigations a hybrid approach was implemented using the boundary element method to calculate the source directivity and a three-dimensional ray-tracing algorithm to estimate the transmission loss. The angle-dependence of the sound field as well as the weather-dependence of the transmission loss are compared to experimental results gathered at the offshore wind farm alpha ventus, located 45?km north of the island Borkum. While theoretical and experimental results are in general agreement, the implemented model slightly underestimates scattering at the rough sea surface. It is found that the source level of 200?dB re 1??Pa at 1?m is adequate to satisfy the detectability of the warning sequence at distances up to 2 NM (?3.7?km) within a horizontal sector of ±60° if realistic assumptions about signal-processing and noise are made. An arrangement to enlarge the angular coverage is discussed. PMID:24180764

Fricke, Moritz B; Rolfes, Raimund

2013-11-01

317

Experimental characterization of statistically independent defects in gate dielectrics-part II: experimental results on flash memory arrays  

Microsoft Academic Search

In this paper we applied the statistical model for independent defects described in Part I, to experimental data measured on Flash memory arrays. The model, developed to describe the stress-induced leakage current (SILC) statistics, allowed us to study the oxide trap generation during program\\/erase (P\\/E) stress and to extract the discrete probability distribution (DPD) of the gate current increase due

Francesco Driussi; Frans Widdershoven; David Esseni; Luca Selmi; Michiel J. van Duuren

2005-01-01

318

Experimental and Theoretical Results in Output-Trajectory Redesign for Flexible Structures  

NASA Technical Reports Server (NTRS)

In this paper we study the optimal redesign of output trajectory for linear invertible systems. This is particularly important for tracking control of flexible structures because the input-state trajectories that achieve the required output may cause excessive vibrations in the structure. A trade-off is then required between tracking and vibrations reduction. We pose and solve this problem as the minimization of a quadratic cost function. The theory is developed and applied to the output tracking of a flexible structure and experimental results are presented.

Dewey, J. S.; Devasia, Santosh

1996-01-01

319

Experimental and computational flow-field results for an all-body hypersonic aircraft  

NASA Technical Reports Server (NTRS)

A comprehensive test program is defined which is being implemented in the NASA/Ames 3.5 foot Hypersonic Wind Tunnel for obtaining data on a generic all-body hypersonic vehicle for computational fluid dynamics (CFD) code validation. Computational methods (approximate inviscid methods and an upwind parabolized Navier-Stokes code) currently being applied to the all-body model are outlined. Experimental and computational results on surface pressure distributions and Pitot-pressure surveys for the basic sharp-nose model (without control surfaces) at a free-stream Mach number of 7 are presented.

Cleary, Joseph W.

1989-01-01

320

Metallic nitrides for corrosion protection in marine environments: Theory compared to experimental results  

SciTech Connect

A theoretical and experimental study was conducted to predict and test the corrosion behavior of metallic nitride films on stainless steel. Theoretical prediction of corrosion resistance properties was conducted by the construction and interpretation of Pourbaix Diagrams for metallic nitrides. Electrochemical Impedance Spectroscopy (EIS) was then employed to determine whether the predicted corrosion protection in a marine environment was obtained. This study found that in most cases, the use of Pourbaix Diagrams to predict corrosion resistance on 304 stainless steel gave accurate results and is a useful technique for material selection of nitride/substrate combinations for corrosion resistance.

Giaimo, A.; Alias, M.N.; Brown, R. [Univ. of Rhode Island, Kingston, RI (United States)

1997-12-01

321

Towards intra-operative OCT guidance for automatic head surgery: first experimental results.  

PubMed

In recent years, optical coherence tomography (OCT) has gained increasing attention not only as an imaging device, but also as a guidance system for surgical interventions. In this contribution, we propose OCT as an external high-accuracy guidance system, and present an experimental setup of an OCT combined with a cutting laser. This setup enables not only in situ monitoring, but also automatic, high-accuracy, three-dimensional navigation and processing. Its applicability is evaluated simulating a robotic assisted surgical intervention, including planning, navigation, and processing. First results demonstrate that OCT is suitable as a guidance system, fulfilling accuracy demands of interventions such as the cochlear implant surgery. PMID:24505780

Díaz, Jesús Díaz; Kundrat, Dennis; Goh, Kim-Fat; Majdani, Omid; Ortmaier, Tobias

2013-01-01

322

Response analysis and experimental results of holography-based modal Zernike wavefront sensor  

NASA Astrophysics Data System (ADS)

The crosstalk problem inherent in holography based modal wavefront sensing (HMWS) becomes more severe with increasing aberrations of the incident beam. In this paper, the cause of crosstalk is theoretically revealed and then demonstrated using simulations. For extending the use of HMWS in correcting atmospheric turbulence introduced aberration, the sensor response is statistically analyzed with random aberrations created in accordance with the atmosphere turbulence model. The system parameters are optimized considering the turbulence strength and calibrated response curves are further used to improve the sensor performance. The simulation and first preliminary experimental results are shown for validating the method.

Dong, Shihao; Haist, Tobias; Osten, Wolfgang; Ruppel, Thomas; Sawodny, Oliver

2011-09-01

323

Simple Experimental Verification of the Relation between the Band-Gap Energy and the Energy of Photons Emitted by LEDs  

ERIC Educational Resources Information Center

The wavelength of the light emitted by a light-emitting diode (LED) is intimately related to the band-gap energy of the semiconductor from which the LED is made. We experimentally estimate the band-gap energies of several types of LEDs, and compare them with the energies of the emitted light, which ranges from infrared to white. In spite of…

Precker, Jurgen W.

2007-01-01

324

Investigations in Experimental and Theoretical High Energy Physics  

SciTech Connect

We report on the work done under DOE grant DE-FG02-01ER41155. The experimental tasks have ongoing efforts at CERN (ATLAS), the Whipple observatory (VERITAS) and R&D work on dual readout calorimetry and neutrino-less double beta decay. The theoretical task emphasizes the weak interaction and in particular CP violation and neutrino physics. The detailed descriptions of the final report on each project are given under the appropriate task section of this report.

Krennrich, Frank [Iowa State University

2013-07-29

325

Influence of a stationary magnetic field on water relations in lettuce seeds. Part II: experimental results.  

PubMed

An experimental study on water absorption by lettuce seeds previously treated in a stationary magnetic field of 0-10 mT is presented. A significant increase in the rate with which the seeds absorb water is observed in the interval 0-10 mT of magnetic treatment. An increment in the total mass of absorbed water in this interval is also observed. These results are consistent with the reports on the increase of germination rate of the seeds, and the theoretical calculation of the variations induced by magnetic fields in the ionic currents across the cellular membrane. The fields originate in changes in the ionic concentration and thus in the osmotic pressure which regulates the entrance of water to the seeds. The good correlation between the theoretical approach and experimental results provides strong evidence that the magnetic field alters the water relations in seeds, and this effect may be the explanation of the reported alterations in germination rate of seeds by the magnetic field. PMID:11748678

Reina, F G; Pascual, L A; Fundora, I A

2001-12-01

326

Fuel-rich, catalytic reaction experimental results. [fuel development for high-speed civil transport aircraft  

NASA Technical Reports Server (NTRS)

Future aeropropulsion gas turbine combustion requirements call for operating at very high inlet temperatures, pressures, and large temperature rises. At the same time, the combustion process is to have minimum pollution effects on the environment. Aircraft gas turbine engines utilize liquid hydrocarbon fuels which are difficult to uniformly atomize and mix with combustion air. An approach for minimizing fuel related problems is to transform the liquid fuel into gaseous form prior to the completion of the combustion process. Experimentally obtained results are presented for vaporizing and partially oxidizing a liquid hydrocarbon fuel into burnable gaseous components. The presented experimental data show that 1200 to 1300 K reaction product gas, rich in hydrogen, carbon monoxide, and light-end hydrocarbons, is formed when flowing 0.3 to 0.6 fuel to air mixes through a catalyst reactor. The reaction temperatures are kept low enough that nitrogen oxides and carbon particles (soot) do not form. Results are reported for tests using different catalyst types and configurations, mass flowrates, input temperatures, and fuel to air ratios.

Rollbuhler, Jim

1991-01-01

327

Comparison of experimental and analytical results for free vibration of laminated composite plates  

SciTech Connect

Fibrous composite materials are being increasingly employed in high performance structures, including pressured vessel and piping applications. These materials are usually used in the form of laminated flat or curved plates, and the understanding of natural frequencies and the corresponding mode shapes is essential to a reliable structural design. Although many references have been published on analytical study of laminated composite plates, a limited number of experimental studies have appeared for dealing with vibration characteristics of the plates. This paper presents both experimental and analytical results for the problems. In the experiment, the holographic interferometry is used to measure the resonant frequencies and corresponding mode shapes of six-layered CFRP (carbon fiber reinforced plastic) composite plates. The material constants of a lamina are calculated from fiber and matrix material constants by using some different composite rules. With the calculated constants, the natural frequencies of the laminated CFRP plates are theoretically determined by the Ritz method. From the comparison of two sets of the results, the effect of choosing different composite rules is discussed in the vibration study of laminated composite plates.

Maryuama, Koichi; Narita, Yoshihiro; Ichinomiya, Osamu [Hokkaido Inst. of Tech., Sapporo (Japan). Dept. of Mechanical Engineering

1995-11-01

328

Epistemology and expectations survey about experimental physics: Development and initial results  

NASA Astrophysics Data System (ADS)

In response to national calls to better align physics laboratory courses with the way physicists engage in research, we have developed an epistemology and expectations survey to assess how students perceive the nature of physics experiments in the contexts of laboratory courses and the professional research laboratory. The Colorado Learning Attitudes about Science Survey for Experimental Physics (E-CLASS) evaluates students' epistemology at the beginning and end of a semester. Students respond to paired questions about how they personally perceive doing experiments in laboratory courses and how they perceive an experimental physicist might respond regarding their research. Also, at the end of the semester, the E-CLASS assesses a third dimension of laboratory instruction, students' reflections on their course's expectations for earning a good grade. By basing survey statements on widely embraced learning goals and common critiques of teaching labs, the E-CLASS serves as an assessment tool for lab courses across the undergraduate curriculum and as a tool for physics education research. We present the development, evidence of validation, and initial formative assessment results from a sample that includes 45 classes at 20 institutions. We also discuss feedback from instructors and reflect on the challenges of large-scale online administration and distribution of results.

Zwickl, Benjamin M.; Hirokawa, Takako; Finkelstein, Noah; Lewandowski, H. J.

2014-06-01

329

Experimental results of a new system using microwaves for vision correction  

NASA Astrophysics Data System (ADS)

Technology is in development to correct vision without the use of lasers or cutting of the eye. Many current technologies used to reshape the cornea are invasive, in that either RF needles are placed into the cornea or a flap is cut and then a laser used to ablate the cornea in the optical zone. Keraflex, a therapeutic microwave treatment, is a noninvasive, non-incisional refractive surgery procedure capable of treating myopia (nearsightedness). The goal is to create a predictable refractive change in the optical zone, while preserving the epithelium and deeper structures of the eye. A further goal is to avoid incisions and damage to the epithelium which both require a post-treatment healing period. Experimental work with fresh porcine eyes examined the following variables: duration of the RF pulse, RF power level, coolant amount and timing, electrode spacing, applanation force against the eye, initial eye temperature, and age of eye. We measured curvature changes of the eye with topography, Scheimpflug, Wavefront aberrometry or other means to characterize diopter change as an important endpoint. Other assessment includes evaluation of a fine white ring seen in the cornea following treatment. Dose studies have been done to correlate the treated region with energy delivered. The timing and dosing of energy and cooling were investigated to achieve the target diopter change in vision.

Ryan, Thomas P.; Pertaub, Radha; Meyers, Steven R.; Dresher, Russell P.; Scharf, Ronald

2009-02-01

330

Negative Refraction and Energy Funneling by Hyperbolic Materials: An Experimental Demonstration in Acoustics  

NASA Astrophysics Data System (ADS)

This Letter reports the design, fabrication, and experimental characterization of hyperbolic materials showing negative refraction and energy funneling of airborne sound. Negative refraction is demonstrated using a stack of five holey Plexiglas plates where their thicknesses, layer separation, hole diameters, and lattice periodicity have been determined to show hyperbolic dispersion around 40 kHz. The resulting hyperbolic material shows a flat band profile in the equifrequency contour allowing the gathering of acoustic energy in a broad range of incident angles and its funneling through the material. Our demonstrations foresee interesting developments based on both phenomena. Acoustic imaging with subwavelength resolution and spot-size converters that harvest and squeeze sound waves irradiating from many directions into a collimated beam are just two possible applications among many.

García-Chocano, Victor M.; Christensen, Johan; Sánchez-Dehesa, José

2014-04-01

331

Proposal for New Experimental Tests of the Bose-Einstein Condensation Mechanism for Low Energy Nuclear Reaction and Transmutation Processes in Deuterium Loaded Micro and Nano Scale Cavities  

Microsoft Academic Search

Most of experimental results of low energy nuclear reaction (LENR) reported so far cannot be reproduced on demand. There have been persistent experimental results indicating that the LENR and transmutation processes in condensed matters (LENRTPCM) are surface phenomena rather than bulk phenomena. Recently proposed Bose-Einstein condensation (BEC) mechanism may provide a suitable theoretical description of the surface phenomena. New experiments

Yeong E. Kim; David S. Koltick; Ronald G. Reifenberger; Alexander L. Zubarev

332

Experimental results on the design for the APS PID global orbit control system.  

SciTech Connect

The Advanced Photon Source third generation synchrotrons light source needs a stabilized particle beam position to produce high brightness and low emittance radiation. Global orbit correction control is introduced and is utilized to satisfy the demanding needs of the accelerator. This paper presents the experimental results for determining an effective and optimal controller to meet the global orbit correction requirements. These requirements include frequency/time domain demands consisting of vibrational noise attenuation, limiting of controller gains for stability and improving the system time response. Experiments were conducted with a digital signal processor implementing various PID sets to make comparisons between simulations and experiments. Measurements at these PID sets supported the results of software simulation.

Chung, Y.; Kirchman, J. A.

1997-12-05

333

Experimental results of exothermic reaction with concentration gradient catalyst in a solar chemical heat pump  

SciTech Connect

Solar chemical heat pump can upgrade the low temperature solar heat about 80 C to about 150--200 C by the reversible chemical reactions of 2-propanol/acetone/hydrogen, which are composed of endothermic and exothermic reactions. In the exothermic process of above reaction, a temperature peak occurs near the inlet of reaction zone in the case of arranging catalyst uniformly. Such a temperature distribution is not suitable for heat exchange. Therefore, the authors arrange the concentration of catalyst gradationally so as not to occur the temperature peak. In this paper, experimental results of exothermic reaction with concentration gradient catalyst in a double tubular exothermic reactor are presented. These results show that the arrangement of concentration gradient catalyst has the possibility about the temperature control in the catalytic reactor.

Takashima, Takumi; Doi, Takuya; Ando, Yuji; Tanaka, Tadayoshi [Electrotechnical Lab., Tsukuba, Ibaraki (Japan); Miyahara, Ryosuke; Kamoshida, Junji [Shibaura Inst. of Tech., Omiya, Saitama (Japan)

1997-12-31

334

Quantitative measurements of ambient radiation, emissivity, and truth temperature of a greybody - Methods and experimental results  

NASA Astrophysics Data System (ADS)

By regarding the total ambient radiation falling on a gray body as an equivalent radiation of a black body at temperature T(B) and by using two standard reference plates, it is possible to measure accurately the ambient radiation. In addition to the ambient radiation, there are two factors still affecting the self-radiation of a gray body, i.e., the emissivity and the true temperature T. It is shown theoretically that the emissivity could be determined by changing the ambient radiation. Two simple methods are proposed for measuring the emissivity, and good results are obtained for a variety of gray bodies. These methods are not only practical in the laboratory but also in the field. The experimental results agree well with the data published by other investigators. Once T(B) and emissivity have been measured, T can be obtained. Based on the theory presented here, a new IR thermometer giving T directly was designed and built.

Zhang, You-Wen; Zhang, Cai-Gen; Klemas, Victor

1986-10-01

335

Experimental Analysis of a Piezoelectric Energy Harvesting System for Harmonic, Random, and Sine on Random Vibration  

SciTech Connect

Formal journal article Experimental analysis of a piezoelectric energy harvesting system for harmonic, random, and sine on random vibration Abstract: Harvesting power with a piezoelectric vibration powered generator using a full-wave rectifier conditioning circuit is experimentally compared for varying sinusoidal, random and sine on random (SOR) input vibration scenarios. Additionally, the implications of source vibration characteristics on harvester design are discussed. Studies in vibration harvesting have yielded numerous alternatives for harvesting electrical energy from vibrations but piezoceramics arose as the most compact, energy dense means of energy transduction. The rise in popularity of harvesting energy from ambient vibrations has made piezoelectric generators commercially available. Much of the available literature focuses on maximizing harvested power through nonlinear processing circuits that require accurate knowledge of generator internal mechanical and electrical characteristics and idealization of the input vibration source, which cannot be assumed in general application. In this manuscript, variations in source vibration and load resistance are explored for a commercially available piezoelectric generator. We characterize the source vibration by its acceleration response for repeatability and transcription to general application. The results agree with numerical and theoretical predictions for in previous literature that load optimal resistance varies with transducer natural frequency and source type, and the findings demonstrate that significant gains are seen with lower tuned transducer natural frequencies for similar source amplitudes. Going beyond idealized steady state sinusoidal and simplified random vibration input, SOR testing allows for more accurate representation of real world ambient vibration. It is shown that characteristic interactions from more complex vibrational sources significantly alter power generation and power processing requirements by increasing harvested power, shifting optimal conditioning impedance, inducing significant voltage supply fluctuations and ultimately rendering idealized sinusoidal and random analyses insufficient.

Cryns, Jackson W.; Hatchell, Brian K.; Santiago-Rojas, Emiliano; Silvers, Kurt L.

2013-07-01

336

Experimental Analysis of Task-based Energy Consumption in Cloud Computing Systems  

E-print Network

Experimental Analysis of Task-based Energy Consumption in Cloud Computing Systems Feifei Chen, John is that large cloud data centres consume large amounts of energy and produce significant carbon footprints that minimise energy consumption while guaranteeing Service Level Agreements (SLAs). In order to achieve

Schneider, Jean-Guy

337

Contribution from the experimental apparatus to the low energy background in Rutherford backscattering experiments  

Microsoft Academic Search

Low energy background was observed while bombarding a thin gold foil with protons. Measurements performed in different experimental arrangements and scattering calculations indicate that a large part of this background must arise from the pure energy definition of the bombarding beam. Particles of unknown origin and of lower energy than the nominal bombarding one were observed by which a separate

L. Varga

1986-01-01

338

Collisions induced by halo and weakly bound nuclei around the Coulomb barrier: experimental results at INFN-LNS  

NASA Astrophysics Data System (ADS)

The study of nuclear collisions involving halo or weakly bound nuclei, at energies around the Coulomb barrier, had a considerable interest in the last decade since the peculiar structure of such nuclei can deeply affect the reaction dynamics. In this paper will summarize some of the experimental results obtained by our group at INFN-LNS over the last years in collisions induced by the halo nuclei 6He and nBe and the stable weakly bound nuclei 6Li and 7Li. Very strong entrance channel effects have been observed in elastic scattering, fusion and direct processes comparing collision induced by the 6He and nBe halo nuclei with the ones induced on the same target by their cores 4He and 10Be. Collisions induced by the stable weakly bound nuclei 6Li, 7Li shows some peculiarities in comparison to the ones induced by well bound nuclei, such as absence of usual threshold anomaly in the optical potential and strong competition of complete fusion with incomplete fusion and transfer in the heavy residue production cross sections. Our experimental results are compared with the ones of other authors, in order to give an overview of our present understanding of the discussed topic.

Figuera, P.

2014-05-01

339

Energy Results of ISO 50001 Deployment by Program Administrators  

E-print Network

results, and since its release in 2011 numerous companies around the world have deployed it. At the same time, program administrators from leading utilities and resource acquisition organizations have implemented energy efficiency programs that target...

Brown, K.; Gilless, C.; Milward, R.

2013-01-01

340

Recovery of yttrium from cathode ray tubes and lamps’ fluorescent powders: experimental results and economic simulation  

SciTech Connect

Highlights: • Fluorescent powder of lamps. • Fluorescent powder of cathode ray rubes. • Recovery of yttrium from fluorescent powders. • Economic simulation for the processes to recover yttrium from WEEE. - Abstract: In this paper, yttrium recovery from fluorescent powder of lamps and cathode ray tubes (CRTs) is described. The process for treating these materials includes the following: (a) acid leaching, (b) purification of the leach liquors using sodium hydroxide and sodium sulfide, (c) precipitation of yttrium using oxalic acid, and (d) calcinations of oxalates for production of yttrium oxides. Experimental results have shown that process conditions necessary to purify the solutions and recover yttrium strongly depend on composition of the leach liquor, in other words, whether the powder comes from treatment of CRTs or lamp. In the optimal experimental conditions, the recoveries of yttrium oxide are about 95%, 55%, and 65% for CRT, lamps, and CRT/lamp mixture (called MIX) powders, respectively. The lower yields obtained during treatments of MIX and lamp powders are probably due to the co-precipitation of yttrium together with other metals contained in the lamps powder only. Yttrium loss can be reduced to minimum changing the experimental conditions with respect to the case of the CRT process. In any case, the purity of final products from CRT, lamps, and MIX is greater than 95%. Moreover, the possibility to treat simultaneously both CRT and lamp powders is very important and interesting from an industrial point of view since it could be possible to run a single plant treating fluorescent powder coming from two different electronic wastes.

Innocenzi, V., E-mail: valentina.innocenzi1@univaq.it; De Michelis, I.; Ferella, F.; Vegliò, F.

2013-11-15

341

Experimental and calculational results from the Spent Fuel Test-Climax  

SciTech Connect

The Spent Fuel Test-Climax (SFT-C) is being conducted under the technical direction of the Lawrence Livermore National Laboratory for the US Department of Energy. The SFT-C is located 420 m below surface in the Climax placed in test storage in April and May 1980. At the same time, 6 electrical elevated-temperature phase of the test. Data related to heat transfer, thermomechanical response, radiation dose, and radiation damage have been collected and are presented here, as appropriate, with calculational results. In general, measured and calculated results compare well.

Patrick, W.C.; Ramspott, L.D.; Ballou, L.B.

1982-10-14

342

Drying in porous media with gravity-stabilized fronts: Experimental results  

NASA Astrophysics Data System (ADS)

In a recent paper [Yiotis , Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.85.046308 85, 046308 (2012)] we developed a model for the drying of porous media in the presence of gravity. It incorporated effects of corner film flow, internal and external mass transfer, and the effect of gravity. Analytical results were derived when gravity opposes drying and hence leads to a stable percolation drying front. In this paper, we test the theory using laboratory experiments. A series of isothermal drying experiments in glass bead packings saturated with volatile hydrocarbons is conducted. The transparent glass cells containing the packing allow for the visual monitoring of the phase distribution patterns below the surface, including the formation of liquid films, as the gaseous phase invades the pore space, and for the control of the thickness of the diffusive mass boundary layer over the packing. The experimental results agree very well with theory, provided that the latter is generalized to account for the effects of corner roundness in the film region (which was neglected in the theoretical part). We demonstrate the existence of an early constant rate period (CRP), which lasts as long as the films saturate the surface of the packing, and of a subsequent falling rate period (FRP), which begins practically after the detachment of the film tips from the external surface. During the CRP, the process is controlled by diffusion within the stagnant gaseous phase in the upper part of the cells, yielding a Stefan tube problem solution. During the FRP, the process is controlled by diffusion within the packing, with a drying rate inversely proportional to the observed position of the film tips in the cell. Theoretical and experimental results compare favorably for a specific value of the roundness of the films, which is found to be constant and equal to 0.2 for various conditions, and verify the theoretical dependence on the capillary Caf, Bond Bo, and Sherwood Sh numbers.

Yiotis, A. G.; Salin, D.; Tajer, E. S.; Yortsos, Y. C.

2012-08-01

343

Preliminary results of the LLNL airborne experimental test-bed SAR system  

SciTech Connect

The Imaging and Detection Program (IDP) within Laser Programs at Lawrence Livermore National Laboratory (LLNL) in cooperation with the Hughes Aircraft Company has developed a versatile, high performance, airborne experimental test-bed (AETB) capability. The test-bed has been developed for a wide range of research and development experimental applications including radar and radiometry plus, with additional aircraft modifications, optical systems. The airborne test-bed capability has been developed within a Douglas EA-3B Skywarrior jet aircraft provided and flown by Hughes Aircraft Company. The current test-bed payload consists of an X-band radar system, a high-speed data acquisition, and a real-time processing capability. The medium power radar system is configured to operate in a high resolution, synthetic aperture radar (SAR) mode and is highly configurable in terms of waveforrns, PRF, bandwidth, etc. Antennas are mounted on a 2-axis gimbal in the belly radome of the aircraft which provides pointing and stabilization. Aircraft position and antenna attitude are derived from a dedicated navigational system and provided to the real-time SAR image processor for instant image reconstruction and analysis. This paper presents a further description of the test-bed and payload subsystems plus preliminary results of SAR imagery.

Miller, M.G.; Mullenhoff, C.J.; Kiefer, R.D.; Brase, J.M.; Wieting, M.G.; Berry, G.L.; Jones, H.E.

1996-01-16

344

[Therapy of Amanita phalloides poisoning. Results of clinical and experimental studies].  

PubMed

On the basis of experimental and clinical results evidence accumulates that supportive therapy is still the milestone in the therapy of death cap poisoning. Today the letality is 20%. The main cause of the intoxication are the amatoxines which inhibit DNA dependent RNA Polymerase II or B. Parts of the supportive therapy are: diuresis with 150--200 ml urin/hour, careful corrections of disturbances in electrolyte and acid-base-metabolism, oral administration of charcoal and oral gut sterilization. In spite of a multitude of experimental and clinical reports on the effectivity of Penicillin G, thiocticacid and steroids there are no controlled studies to demonstrate the advantage of one regimen over the other. The time course of resorption and excretion of amatoxines clearly shows that hemoperfusion and/or hemodialysis are only of value if applied within the first 24 hours after poisoning. At this time neither anamnestic nor biochemical data give any clues to the probable course of the disease. Heterologous baboon liver perfusion may be lifesaving in coma hepaticum grade IV, but the small amount of cases so far does not yet allow any comments on its effectivity. PMID:389769

von Clarmann, M; Mathes, G; Weber, T; Erhardt, W; Kircher, G; Fischer, M

1979-11-15

345

Distribution of fasciolosis in Kansas, with results of experimental snail susceptibility studies.  

PubMed

A total of 278 veterinarians throughout Kansas were sent mail-in survey forms asking specific questions relating to their experience with fasciolosis in their practice area. Replies were received from 178 (64%) veterinarians representing six practice types; one-third reported having seen cases of fasciolosis in their practice. The results of our survey indicate that the majority of the cattle diagnosed with liver fluke disease in Kansas are imported from other areas of the USA. However, in both central and southeastern regions of Kansas, some cattle that had never been out of the state were infected with Fasciola hepatica. Thus, these areas of Kansas should be considered endemic for liver fluke disease. Methods of diagnosis, types of operations, and improvements seen after treatment were also discussed. In order to ascertain the existence of one or more possible snail intermediate hosts within Kansas, five species of lymnaeid snails were collected from central and southeastern parts of the state and tested for their susceptibility to infection by Fasciola hepatica. The snails collected included Pseudosuccinea columella, Fossaria obrussa, Fossaria bulimoides, Fossaria parva and Fossaria dalli. Of these, Pseudosuccinea columella and Fossaria bulimoides proved susceptible to experimental infection by Fasciola hepatica. Metacercariae obtained from experimentally infected snails were used to infect both a weanling calf thereby completing the life cycle of the parasite. This report is the first to identify the existence of suitable snail intermediate hosts for Fasciola hepatica in Kansas. PMID:7754605

McKown, R D; Ridley, R K

1995-02-01

346

Experimental results of flooding experiments in an inclined tube with liquid nitrogen and its vapor  

NASA Astrophysics Data System (ADS)

Counter-current two-phase flow behaviors of saturated liquid nitrogen and its vapor at the onset of flooding are experimentally investigated. The experiments are carried out in a vacuum-insulated 20 mm i.d. transparent tube with the inclination angles of 30°, 45° and 60° corresponding to the horizontal. The common slug flow phenomenon happened with water-air is not observed with liquid nitrogen-vapor, instead, the big interfacial wave is found to be crushed to tiny droplets. The phenomenal difference is primarily attributed to the larger viscosity of water than liquid nitrogen. Correspondingly, the sharp rise of pressure drop with water-air is largely due to the blockage of gas flow by the formed slug, while it is primarily due to the tiny droplet entrainment for the liquid nitrogen-vapor pairs. The effects of inclination angles on the incipient flooding velocity are specially emphasized and investigated. A new correlation base on Ohnesorge number and modified Froude number are presented, and the results coincide with the experimental data of both room-temperature and cryogenic fluids with the uncertainty of 20%.

Chen, Jianye; Xu, Lu; Xiong, Wei; Qiu, Limin; Zhang, Xiaobin

2014-07-01

347

Preliminary experimental investigation of in vivo magnetic manipulation: results and potential application in hyperthermia.  

PubMed

The first in vivo experiments in support of a new technique for delivering stereotaxic hyperthermia have been conducted at the Experimental Surgery Facility of the University of Virginia's Medical Center. We call this technique the "Video Tumor Fighter." In each of twelve trials a single, small permanent magnet or train of small permanent magnets was implanted on the brain surface of adult canine models. In three of the trials, this "seed" (typically 6-mm diameter X 6-mm long) was moved by magnetic manipulation to different locations within the brain. In two other trials, the seed moved along the interface between the brain and the inner vault of the skull. The noncontact magnetic manipulation was accomplished by coupling the permanently magnetized seed to the large dc magnetic field gradient created by a water-cooled coil surrounding the animal's head. The seed's motions were monitored with x-ray fluoroscopy; its rate of movement was found to be approximately 0.8 mm s-1. The forces required to produce these motions were on the order of 0.07 N. We document here the instrumentation used in these trials, describe the experimental procedures employed, and discuss the technical aspects of the results. PMID:2654597

Grady, M S; Howard, M A; Molloy, J A; Ritter, R C; Quate, E G; Gillies, G T

1989-01-01

348

Thermodiffusion in concentrated ferrofluids: Experimental and numerical results on magnetic thermodiffusion  

SciTech Connect

Ferrofluids consist of magnetic nanoparticles dispersed in a carrier liquid. Their strong thermodiffusive behaviour, characterised by the Soret coefficient, coupled with the dependency of the fluid's parameters on magnetic fields is dealt with in this work. It is known from former experimental investigations on the one hand that the Soret coefficient itself is magnetic field dependent and on the other hand that the accuracy of the coefficient's experimental determination highly depends on the volume concentration of the fluid. The thermally driven separation of particles and carrier liquid is carried out with a concentrated ferrofluid (? = 0.087) in a horizontal thermodiffusion cell and is compared to equally detected former measurement data. The temperature gradient (1 K/mm) is applied perpendicular to the separation layer. The magnetic field is either applied parallel or perpendicular to the temperature difference. For three different magnetic field strengths (40 kA/m, 100 kA/m, 320 kA/m) the diffusive separation is detected. It reveals a sign change of the Soret coefficient with rising field strength for both field directions which stands for a change in the direction of motion of the particles. This behaviour contradicts former experimental results with a dilute magnetic fluid, in which a change in the coefficient's sign could only be detected for the parallel setup. An anisotropic behaviour in the current data is measured referring to the intensity of the separation being more intense in the perpendicular position of the magnetic field: S{sub T?} = ?0.152 K{sup ?1} and S{sub T?} = ?0.257 K{sup ?1} at H = 320 kA/m. The ferrofluiddynamics-theory (FFD-theory) describes the thermodiffusive processes thermodynamically and a numerical simulation of the fluid's separation depending on the two transport parameters ?{sub ?} and ?{sub ?} used within the FFD-theory can be implemented. In the case of a parallel aligned magnetic field, the parameter can be determined to ?{sub ?} = (2.8;?9.1;?11.2)?×?10{sup ?11}?·?D{sub ?} kg/(A{sup 2}m) for the different field strengths and in dependence on the magnetic diffusion coefficient D{sub ?}. An adequate fit in the perpendicular case is not possible, by ?{sub ?} = 1?×?10{sup ?17} kg/(Am{sup 2}) a rather good agreement between numerical and experimental data can be found for a field strength of 40 kA/m, a change in the coefficient's sign in the perpendicular setup is not numerically determinable via this theory. The FFD-theory is only partly applicable to calculate the concentration profile in concentrated magnetic fluids established due to a temperature gradient and magnetic field applied.

Sprenger, Lisa, E-mail: Lisa.Sprenger@tu-dresden.de; Lange, Adrian; Odenbach, Stefan [Institute of Fluid Mechanics, Chair of Magnetofluiddynamics, Measuring and Automation Technology, TU Dresden, 01062 Dresden (Germany)] [Institute of Fluid Mechanics, Chair of Magnetofluiddynamics, Measuring and Automation Technology, TU Dresden, 01062 Dresden (Germany)

2014-02-15

349

Thermodiffusion in concentrated ferrofluids: Experimental and numerical results on magnetic thermodiffusion  

NASA Astrophysics Data System (ADS)

Ferrofluids consist of magnetic nanoparticles dispersed in a carrier liquid. Their strong thermodiffusive behaviour, characterised by the Soret coefficient, coupled with the dependency of the fluid's parameters on magnetic fields is dealt with in this work. It is known from former experimental investigations on the one hand that the Soret coefficient itself is magnetic field dependent and on the other hand that the accuracy of the coefficient's experimental determination highly depends on the volume concentration of the fluid. The thermally driven separation of particles and carrier liquid is carried out with a concentrated ferrofluid (? = 0.087) in a horizontal thermodiffusion cell and is compared to equally detected former measurement data. The temperature gradient (1 K/mm) is applied perpendicular to the separation layer. The magnetic field is either applied parallel or perpendicular to the temperature difference. For three different magnetic field strengths (40 kA/m, 100 kA/m, 320 kA/m) the diffusive separation is detected. It reveals a sign change of the Soret coefficient with rising field strength for both field directions which stands for a change in the direction of motion of the particles. This behaviour contradicts former experimental results with a dilute magnetic fluid, in which a change in the coefficient's sign could only be detected for the parallel setup. An anisotropic behaviour in the current data is measured referring to the intensity of the separation being more intense in the perpendicular position of the magnetic field: ST? = -0.152 K-1 and ST? = -0.257 K-1 at H = 320 kA/m. The ferrofluiddynamics-theory (FFD-theory) describes the thermodiffusive processes thermodynamically and a numerical simulation of the fluid's separation depending on the two transport parameters ?? and ?? used within the FFD-theory can be implemented. In the case of a parallel aligned magnetic field, the parameter can be determined to ?? = {2.8; 9.1; 11.2} × 10-11 . D? kg/(A2m) for the different field strengths and in dependence on the magnetic diffusion coefficient D?. An adequate fit in the perpendicular case is not possible, by ?? = 1 × 10-17 kg/(Am2) a rather good agreement between numerical and experimental data can be found for a field strength of 40 kA/m, a change in the coefficient's sign in the perpendicular setup is not numerically determinable via this theory. The FFD-theory is only partly applicable to calculate the concentration profile in concentrated magnetic fluids established due to a temperature gradient and magnetic field applied.

Sprenger, Lisa; Lange, Adrian; Odenbach, Stefan

2014-02-01

350

Implementation and experimental results of 4D tumor tracking using robotic couch  

PubMed Central

Purpose: This study presents the implementation and experimental results of a novel technique for 4D tumor tracking using a commercially available and commonly used treatment couch and evaluates the tumor tracking accuracy in clinical settings. Methods: Commercially available couch is capable of positioning the patient accurately; however, currently there is no provision for compensating physiological movement using the treatment couch in real-time. In this paper, a real-time couch tracking control technique is presented together with experimental results in tumor motion compensation in four dimensions (superior-inferior, lateral, anterior-posterior, and time). To implement real-time couch motion for tracking, a novel control system for the treatment couch was developed. The primary functional requirements for this novel technique were: (a) the treatment couch should maintain all previous/normal features for patient setup and positioning, (b) the new control system should be used as a parallel system when tumor tracking would be deployed, and (c) tracking could be performed in a single direction and/or concurrently in all three directions of the couch motion (longitudinal, lateral, and vertical). To the authors’ best knowledge, the implementation of such technique to a regular treatment couch for tumor tracking has not been reported so far. To evaluate the performance of the tracking couch, we investigated the mechanical characteristics of the system such as system positioning resolution, repeatability, accuracy, and tracking performance. Performance of the tracking system was evaluated using dosimetric test as an endpoint. To investigate the accuracy of real-time tracking in the clinical setting, the existing clinical treatment couch was replaced with our experimental couch and the linear accelerator was used to deliver 3D conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) treatment plans with and without tracking. The results of radiation dose distribution from these two sets of experiments were compared and presented here. Results: The mechanical accuracies were 0.12, 0.14, and 0.18 mm in X, Y, and Z directions. The repeatability of the desired motion was within ±0.2 mm. The differences of central axis dose between the 3D-CRT stationary plan and two tracking plans with different motion trajectories were 0.21% and 1.19%. The absolute dose differences of both 3D tracking plans comparing to the stationary plan were 1.09% and 1.20%. Comparing the stationary IMRT plan with the tracking IMRT plan, it was observed that the central axis dose difference was ?0.87% and the absolute difference of both IMRT plans was 0.55%. Conclusions: The experimental results revealed that the treatment couch could be successfully used for real-time tumor tracking with a high level of accuracy. It was demonstrated that 4D tumor tracking was feasible using existing couch with implementation of appropriate tracking methodology and with modifications in the control system. PMID:23127089

Buzurovic, I.; Yu, Y.; Werner-Wasik, M.; Biswas, T.; Anne, P. R.; Dicker, A. P.; Podder, T. K.

2012-01-01

351

Implementation and experimental results of 4D tumor tracking using robotic couch  

SciTech Connect

Purpose: This study presents the implementation and experimental results of a novel technique for 4D tumor tracking using a commercially available and commonly used treatment couch and evaluates the tumor tracking accuracy in clinical settings. Methods: Commercially available couch is capable of positioning the patient accurately; however, currently there is no provision for compensating physiological movement using the treatment couch in real-time. In this paper, a real-time couch tracking control technique is presented together with experimental results in tumor motion compensation in four dimensions (superior-inferior, lateral, anterior-posterior, and time). To implement real-time couch motion for tracking, a novel control system for the treatment couch was developed. The primary functional requirements for this novel technique were: (a) the treatment couch should maintain all previous/normal features for patient setup and positioning, (b) the new control system should be used as a parallel system when tumor tracking would be deployed, and (c) tracking could be performed in a single direction and/or concurrently in all three directions of the couch motion (longitudinal, lateral, and vertical). To the authors' best knowledge, the implementation of such technique to a regular treatment couch for tumor tracking has not been reported so far. To evaluate the performance of the tracking couch, we investigated the mechanical characteristics of the system such as system positioning resolution, repeatability, accuracy, and tracking performance. Performance of the tracking system was evaluated using dosimetric test as an endpoint. To investigate the accuracy of real-time tracking in the clinical setting, the existing clinical treatment couch was replaced with our experimental couch and the linear accelerator was used to deliver 3D conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) treatment plans with and without tracking. The results of radiation dose distribution from these two sets of experiments were compared and presented here. Results: The mechanical accuracies were 0.12, 0.14, and 0.18 mm in X, Y, and Z directions. The repeatability of the desired motion was within {+-}0.2 mm. The differences of central axis dose between the 3D-CRT stationary plan and two tracking plans with different motion trajectories were 0.21% and 1.19%. The absolute dose differences of both 3D tracking plans comparing to the stationary plan were 1.09% and 1.20%. Comparing the stationary IMRT plan with the tracking IMRT plan, it was observed that the central axis dose difference was -0.87% and the absolute difference of both IMRT plans was 0.55%. Conclusions: The experimental results revealed that the treatment couch could be successfully used for real-time tumor tracking with a high level of accuracy. It was demonstrated that 4D tumor tracking was feasible using existing couch with implementation of appropriate tracking methodology and with modifications in the control system.

Buzurovic, I.; Yu, Y.; Werner-Wasik, M.; Biswas, T.; Anne, P. R.; Dicker, A. P.; Podder, T. K. [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Department of Radiation Oncology, University Hospitals Case Medical Center, Cleveland, Ohio 44106 (United States); Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107 (United States); Department of Radiation Oncology, University Hospitals Case Medical Center, Cleveland, Ohio 44106 (United States)

2012-11-15

352

EASE (Experimental Assembly of Structures in EVA) overview of selected results  

NASA Technical Reports Server (NTRS)

Experimental Assembly of Structures in EVA (EASE) objectives, experimental protocol, neutral buoyancy simulation, task time distribution, assembly task performance, metabolic rate/biomedical readouts are summarized. This presentation is shown in charts, figures, and graphs.

Akin, David L.

1987-01-01

353

Small Buoys for Energy Harvesting : Experimental and Numerical Modeling Studies  

E-print Network

resilient systems, to provide a renewable wave power source of ( kW for distributed marine surveillance of Ocean Engineering, University of Rhode Island, Narragansett, RI, USA 2. Electro Standards Laboratories for wave energy harvesting (free-floating or slackly moored), to produce about 1 KW per unit at full scale

Grilli, Stéphan T.

354

Experimental demonstrations for teaching electromagnetic fields and energy  

Microsoft Academic Search

The MIT course `electromagnetic fields and energy' is the first of a two-course sequence which typically includes electrical engineering juniors who have seen Maxwell's equations in integral and differential form in freshman physics, with some exposure to integral theorems and differential operators in freshman calculus. The course simplifies Maxwell's equations into their electroquasistatic (EQS) and magnetoquasistatic (MQS) forms and takes

M. Zahn; J. R. Melcher; H. A. Haus

1990-01-01

355

Preliminary experimental results on studying possibility of variable mass liner (VML) formation  

SciTech Connect

The main objective of the present experiment was to study the formation process and initial stage of acceleration of a variable-mass plasma liner (VML). The method is based on magnetic acceleration of a liner with the mass reduced during such acceleration. The experiment was carried out on February 16 at VNIIEF. This report describes the results of measurements obtained in the experiment and preliminary analysis of the results characterizing operation of the test facility main units: helical EMG; 5-module disk EMG 400 mm in diameter (DEMG); ponderomotive unit (PU) with a cylindric condensed liner and a special tooth-cutoff. The first part of the report presents measurement results obtained on the VNIIEF`s diagnostic equipment that are compared with those obtained by American specialists on their diagnostic equipment. Information submitted by American specialists is included in part 2 of this report. The second part of the report presents preliminary computational-theoretic analysis of the main measured results describing operation of DEMG TL system in the experiment; experimental data are compared with theoretical ones obtained before and after the experiment. But more emphasis is placed on the data preliminary analysis indicating that in the experiment a variable mass liner is formed (VML or plasma bubble).

NONE

1995-12-31

356

Experimental analysis of an energy self sufficient ocean buoy utilizing a bi-directional turbine  

E-print Network

An experimental analysis of a Venturi shrouded hydro turbine for wave energy conversion. The turbine is designed to meet the specific power requirements of a, Woods Hole Oceanographic Institute offshore monitoring buoy ...

Gruber, Timothy J. (Timothy James)

2012-01-01

357

Experimental Evidence of Threshold Effects in the Energy Loss of Protons in Carbon and Aluminum due to Inner Shell Ionization  

NASA Astrophysics Data System (ADS)

We explore the contributions of inner shell ionization to the energy loss of 7 to 270 keV protons in C and Al foils under experimental conditions such that the product of the observation angle and the projectile energy is kept constant. By normalizing these energy loss measurements to the energy loss in the forward direction we observe a pronounced rising behavior with increasing energy. This effect appears in the same range of energies where the respective K- and L-shell ionization cross sections of these elements show a similar threshold behavior. Based also on various theoretical considerations we interpret these results as clear evidence of the inner shell ionization contribution to the energy loss.

Famá, M.; Eckardt, J. C.; Lantschner, G. H.; Arista, N. R.

2000-11-01

358

Inlet Flow Test Calibration for a Small Axial Compressor Facility. Part 1: Design and Experimental Results  

NASA Technical Reports Server (NTRS)

An axial compressor test rig has been designed for the operation of small turbomachines. The inlet region consisted of a long flowpath region with two series of support struts and a flapped inlet guide vane. A flow test was run to calibrate and determine the source and magnitudes of the loss mechanisms in the inlet for a highly loaded two-stage axial compressor test. Several flow conditions and IGV angle settings were established in which detailed surveys were completed. Boundary layer bleed was also provided along the casing of the inlet behind the support struts and ahead of the IGV. A detailed discussion of the flowpath design along with a summary of the experimental results are provided in Part 1.

Miller, D. P.; Prahst, P. S.

1994-01-01

359

An aerodynamic analysis of the autogiro rotor with a comparison between calculated and experimental results  

NASA Technical Reports Server (NTRS)

This report presents an extension of the autogiro theory of Glauert and Lock in which the influence of a pitch varying with the blade radius is evaluated and methods of approximating the effect of blade tip losses and the influence of reversed velocities on the retreating blades are developed. A comparison of calculated and experimental results showed that most of the rotor characteristics could be calculated with reasonable accuracy, and that the type of induced flow assumed has a secondary effect upon the net rotor forces, although the flapping motion is influenced appreciably. An approximate evaluation of the effect of parasite drag on the rotor blades established the importance of including this factor in the analysis.

Wheatley, John B

1935-01-01

360

Experimental Results from Droop Compensation for the High Voltage Converter Modulators  

SciTech Connect

The High Voltage Convertor Modulators are used to power the RF klystrons used throughout the linear accelerator at the Spallation Neutron Source. The output voltage of the modulator has significant voltage droop and ripple which, combined with low level RF system limitations, affect performance and stability of the accelerator cavities. In conjunction with the progress in the development of the new controller, different modulation techniques were implemented and studied on the test modulator. This paper discusses experimental results from implementation of different modulation schemes has on the modulator output voltage pulse. Thermal measurements were carried out to determine the effect of these modulations schemes on long term reliability of the modulator. Future plans are also discussed.

Patel, Gunjan P [ORNL; Anderson, David E [ORNL; Peplov, Vladimir V [ORNL; Saethre, Robert B [ORNL; Solley, Dennis J [ORNL; Wezensky, Mark W [ORNL

2013-01-01

361

Simulation and experimental results of optical and thermal modeling of gold nanoshells.  

PubMed

This paper proposes a generalized method for optical and thermal modeling of synthesized magneto-optical nanoshells (MNSs) for biomedical applications. Superparamagnetic magnetite nanoparticles with diameter of 9.5 ± 1.4 nm are fabricated using co-precipitation method and subsequently covered by a thin layer of gold to obtain 15.8 ± 3.5 nm MNSs. In this paper, simulations and detailed analysis are carried out for different nanoshell geometry to achieve a maximum heat power. Structural, magnetic and optical properties of MNSs are assessed using vibrating sample magnetometer (VSM), X-ray diffraction (XRD), UV-VIS spectrophotometer, dynamic light scattering (DLS), and transmission electron microscope (TEM). Magnetic saturation of synthesized magnetite nanoparticles are reduced from 46.94 to 11.98 emu/g after coating with gold. The performance of the proposed optical-thermal modeling technique is verified by simulation and experimental results. PMID:25063109

Ghazanfari, Lida; Khosroshahi, Mohammad E

2014-09-01

362

Prestress effects on the eigenfrequencies of the soundboards: experimental results on a simplified string instrument.  

PubMed

This paper presents an experimental study of the effects of prestresses on the vibration behavior of string instruments. These prestresses are created by gluing ribs (crowning) and tensioning string (downbearing). The effects of these prestresses were previously studied numerically for a piano soundboard by Mamou-Mani et al. [J. Acoust. Soc. Am. 123, 2401-2406 (2008)] and analytically for simplified models by Mamou-Mani et al. [Acta Acust. Unit. Acust. 95, 915-926 (2009)]. In the present study, a specified test bench is designed, including a simplified soundboard (a rectangular plate), a bridge, and a single string. The plate is subjected to in-plane and transverse loads. Vibrational eigenmodes are identified using nearfield acoustical holography (NAH) measurement. The evolution of eigenfrequencies with these specific prestresses is studied. The results show the effectiveness of NAH for this purpose and a very good qualitative concordance with previous numerical and analytical calculus. PMID:22280709

Mamou-Mani, Adrien; Le Moyne, Sylvie; Ollivier, François; Besnainou, Charles; Frelat, Joël

2012-01-01

363

Physical model and experimental results of cathode erosion related to power supply ripple  

NASA Technical Reports Server (NTRS)

This paper discusses the physical effects of power supply ripple on cathode erosion and cathode arc attachment in a water-cooled, 30 kW nitrogen arcjet. Experimental results are presented for 2 percent thoriated tungsten, which show that the long-term cathode erosion rate is a decreasing function of current ripple over the range 1-13 percent. Above this range, the cathode discharge becomes unstable, and the erosion rate rapidly increases. A qualitative model of this effect is given in terms of a magnetically induced radial motion of the arc column, and an overall increase in the cathode spot radius due to the higher peak current associated with higher ripple. The most important effect of power supply ripple is therefore shown to be its ability to collectively drive the cathode attachment away from the cathode center. This leads to an increase in the cathode attachment area, and a subsequent decrease in the cathode erosion rate.

Harris, W. J.; O'Hair, E. A.; Hatfield, L. L.; Kristiansen, M.

1992-01-01

364

Noise characteristics of upper surface blown configurations. Experimental program and results  

NASA Technical Reports Server (NTRS)

An experimental data base was developed from the model upper surface blowing (USB) propulsive lift system hardware. While the emphasis was on far field noise data, a considerable amount of relevant flow field data were also obtained. The data were derived from experiments in four different facilities resulting in: (1) small scale static flow field data; (2) small scale static noise data; (3) small scale simulated forward speed noise and load data; and (4) limited larger-scale static noise flow field and load data. All of the small scale tests used the same USB flap parts. Operational and geometrical variables covered in the test program included jet velocity, nozzle shape, nozzle area, nozzle impingement angle, nozzle vertical and horizontal location, flap length, flap deflection angle, and flap radius of curvature.

Brown, W. H.; Searle, N.; Blakney, D. F.; Pennock, A. P.; Gibson, J. S.

1977-01-01

365

Modelling Viscoelastic Behaviour of Polymer by A Mixed Velocity, Displacement Formulation - Numerical and Experimental Results  

SciTech Connect

The objective of this work is to model the viscoelastic behaviour of polymer from the solid state to the liquid state. With this objective, we perform experimental tensile tests and compare with simulation results. The chosen polymer is a PMMA whose behaviour depends on its temperature. The computation simulation is based on Navier-Stokes equations where we propose a mixed finite element method with an interpolation P1+/P1 using displacement (or velocity) and pressure as principal variables. The implemented technique uses a mesh composed of triangles (2D) or tetrahedra (3D). The goal of this approach is to model the viscoelastic behaviour of polymers through a fluid-structure coupling technique with a multiphase approach.

Pham, VT.; Silva, L.; Digonnet, H.; Combeaud, C.; Billon, N.; Coupez, T. [Centre for Material Forming (CEMEF), MINES ParisTech, Rue Claude Daunesse, Sophia Antipolis cedex (France)

2011-05-04

366

Polymer Injection Forming (PIF) Of Thin-Walled Sheet Metal Parts — Preliminary Experimental Results  

NASA Astrophysics Data System (ADS)

Polymer Injection Forming (PIF) is a new technology to manufacture sheet metal/polymer macro-composite components in a one-operation production process. During the process, a metal blank is shaped inside an injection mould by using the injection pressure of the molten polymer. In the same step the polymer is permanently bonded to the metal sheet creating a fully finished product in only one production step. Thus, the PIF technology is a combination of the injection moulding and sheet metal forming processes. In this paper, the influence of the main injection moulding process parameters on the sheet metal formability has been experimentally investigated. The results show that melt temperature and clamp force have a great effect on the sheet deformation since they affect respectively the ductility of the sheet metal and the degree of pure drawing. In order to maximize sheet metal formability avoiding the flash formation, the main process parameters have been optimized.

Lucchetta, Giovanni; Baesso, Ruggero

2007-04-01

367

Downstream evolution of turbulence from heated screens: Experimental and analytical results  

SciTech Connect

This report discusses recent efforts to characterize the flow and density nonuniformities downstream of heated screens placed in a uniform flow. The Heated Screen Test Facility (HSTF) at Sandia National Laboratories and the Lockheed Palo Alto Flow Channel (LPAFC) were used to perform experiments over wide ranges of upstream velocities and heating rates. Screens of various mesh configurations were examined, including multiple screens sequentially positioned in the flow direction. Diagnostics in these experiments included pressure manometry, hot-wire anemometry, interferometry, Hartmann wavefront slope sensing, and photorefractive schlieren photography. A model was developed to describe the downstream evolution of the flow and density nonuniformities. Equations for the spatial variation of the mean flow quantities and the fluctuation magnitudes were derived by incorporating empirical correlations into the equations of motion. Numerical solutions of these equations are in fair agreement with previous and current experimental results.

O'Hern, T.J.; Shagam, R.N.; Neal, D.R.; Suo-Anttila, A.J.; Torczynski, J.R.

1993-02-01

368

An experimental investigation of the energy-attenuation capabilities of various-shaped compliable metal structures  

E-print Network

AN EXPERIMENTAL INVESTIGATION OF THE ENERGY ? ATTENUATION CAPABILITIES OF VARIOUS-SHAPED COMPLIABLE METAL STRUCTURES A Thesis By LYNN BLACKMORE HARDING Submitted to the Graduate College of the Texas A6M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE May 1964 Major Subject: Aerospace Engineering AN EXPERIMENTAL INVESTIGATION OF THE ENERGY ? ATTENUATION CAPABILITIES OF VARIOUS-SHAPED COMPLIABLE METAL STRUCTURES A Thesis By LYNN BLACKMORE HARDING...

Harding, Lynn Blackmore

1964-01-01

369

Ultrafast solvation dynamics in water: Isotope effects and comparison with experimental results  

NASA Astrophysics Data System (ADS)

A detailed theoretical study of solvation dynamics in water is presented. The motivation of the present study comes from the recent experimental observation that the dynamics of solvation of an ion in water is ultrafast and the solvation time correlation function decays with a time constant of about 55 fs. The slower decay in the long time can be described by a sum of two exponentials with time constants equal to 126 and 880 fs. The molecular theory (developed earlier) predicts a time constant equal to 52 fs for the initial Gaussian decay and time constants equal to 134 and 886 fs for the two exponential components at the long time. This nearly perfect agreement is obtained by using the most detailed dynamical information available in the literature. The present study emphasizes the importance of the intermolecular vibrational band originating from the O...O stretching mode of the O-H...O units in the initial dynamics and raises several interesting questions regarding the nature of the decay of this mode. We have also studied the effects of isotope substitution on solvation dynamics. It is predicted that a significant isotope effect may be observed in the long time. The experimental results have also been compared with the prediction of the dynamic mean spherical approximation (DMSA); the agreement is not satisfactory at the long time. It is further found that the molecular theory and the DMSA lead to virtually identical results if the translational modes of the solvent molecules are neglected in the former. DMSA has also been used to investigate the dynamics of solvation of a dipolar solute in water. It is found that the dynamics of dipolar solvation exhibit features rather different from those of ion solvation.

Nandi, Nilashis; Roy, Srabani; Bagchi, Biman

1995-01-01

370

Using leg muscles as shock absorbers: theoretical predictions and experimental results of drop landing performance.  

PubMed

The use of muscles as power dissipators is investigated in this study, both from the modellistic and the experimental points of view. Theoretical predictions of the drop landing manoeuvre for a range of initial conditions have been obtained by accounting for the mechanical characteristics of knee extensor muscles, the limb geometry and assuming maximum neural activation. Resulting dynamics have been represented in the phase plane (vertical displacement versus speed) to better classify the damping performance. Predictions of safe landing in sedentary subjects were associated to dropping from a maximum (feet) height of 1.6-2.0 m (about 11 m on the moon). Athletes can extend up to 2.6-3.0 m, while for obese males (m = 100 kg, standard stature) the limit should reduce to 0.9-1.3 m. These results have been calculated by including in the model the estimated stiffness of the 'global elastic elements' acting below the squat position. Experimental landings from a height of 0.4, 0.7, 1.1 m (sedentary males (SM) and male (AM) and female (AF) athletes from the alpine ski national team) showed dynamics similar to the model predictions. While the peak power (for a drop height of about 0.7 m) was similar in SM and AF (AM shows a +40% increase, about 33 W/kg), AF stopped the downward movement after a time interval (0.219 +/- 0.030 s) from touch-down 20% significantly shorter than SM. Landing strategy and the effect of anatomical constraints are discussed in the paper. PMID:9857837

Minetti, A E; Ardigò, L P; Susta, D; Cotelli, F

1998-12-01

371

Experimental Electron Energy Distributions for Townsend Discharges in Argon Gas  

Microsoft Academic Search

In this work the electron energy distribution functions and the anisotropic drift term of the velocity distribution functions in non-self-sustaining (Townsend) discharges in argon were determined by direct measurement for a range of EN (electric field strength per gas-atom concentration) from 70 to 407 townsends (Td) (1 Td=10-17 V cm2). Some structure in the form of the distribution functions is

Jon R. Losee; David S. Burch

1972-01-01

372

Experimental and modeling results of creep fatigue life of Inconel 617 and Haynes 230 at 850 C  

SciTech Connect

Creep fatigue testing of Ni-based superalloy Inconel 617 and Haynes 230 were conducted in the air at 850 C. Tests were performed with fully reversed axial strain control at a total strain range of 0.5%, 1.0% or 1.5% and hold time at maximum tensile strain for 3, 10 or 30 min. In addition, two creep fatigue life prediction methods, i.e. linear damage summation and frequency-modified tensile hysteresis energy modeling, were evaluated and compared with experimental results. Under all creep fatigue tests, Haynes 230 performed better than Inconel 617. Compared to the low cycle fatigue life, the cycles to failure for both materials decreased under creep fatigue test conditions. Longer hold time at maximum tensile strain would cause a further reduction in both material creep fatigue life. The linear damage summation could predict the creep fatigue life of Inconel 617 for limited test conditions, but considerably underestimated the creep fatigue life of Haynes 230. In contrast, frequency-modified tensile hysteresis energy modeling showed promising creep fatigue life prediction results for both materials.

Chen, Xiang [ORNL] [ORNL; Sokolov, Mikhail A [ORNL] [ORNL; Sham, Sam [ORNL] [ORNL; ERDMAN III, DONALD L [ORNL] [ORNL; Busby, Jeremy T [ORNL] [ORNL; Mo, Kun [ORNL] [ORNL; Stubbins, James [ORNL] [ORNL

2013-01-01

373

Comparison of experimental and theoretical results to define centrality of heavy ion collisions  

E-print Network

Using the simulation data coming from the cascade model, we have studied the behavior of event number as a function of impact parameter-b and a number of all charged particles- Nch for light and heavy nuclei at different energies. We have seen that for light nuclei, a number of all charged particles-Nch could be used to fix the centrality. But for heavy nuclei we have got strong initial energy and mass dependences and the results for impact parameter factor dependences and ones for a number of all charged particles differ. So for heavy nuclei, a number of charged particles-Nch could not be use to fix the centrality. Key words: cascade model; centrality, light nuclei, heavy nuclei

Wazir, Z; Khan, E U; Haseeb, Mahnaz Q; Ajaz, M; Khan, K H

2009-01-01

374

Comparison of experimental and theoretical results to define centrality of heavy ion collisions  

E-print Network

Using the simulation data coming from the cascade model, we have studied the behavior of event number as a function of impact parameter-b and a number of all charged particles- Nch for light and heavy nuclei at different energies. We have seen that for light nuclei, a number of all charged particles-Nch could be used to fix the centrality. But for heavy nuclei we have got strong initial energy and mass dependences and the results for impact parameter factor dependences and ones for a number of all charged particles differ. So for heavy nuclei, a number of charged particles-Nch could not be use to fix the centrality. Key words: cascade model; centrality, light nuclei, heavy nuclei

Z. Wazir; M. K. Suleymanov; E. U. Khan; Mahnaz Q. Haseeb; M. Ajaz; K. H. Khan

2009-04-15

375

Experimental Study of Airfoil Trailing Edge Noise: Instrumentation, Methodology and Initial Results. M.S. Thesis  

NASA Technical Reports Server (NTRS)

The mechanisms of aerodynamic noise generation at the trailing edge of an airfoil is investigated. Instrumentation was designed, a miniature semiconductor strain-gauge pressure transducer and associated electronic amplifier circuitry were designed and tested and digital signal analysis techniques applied to gain insight into the relationship between the dynamic pressure close to the trailing edge and the sound in the acoustic far-field. Attempts are made to verify some trailing-edge noise generation characteristics as theoretically predicted by several contemporary acousticians. It is found that the noise detected in the far-field is comprised of the sum of many uncorrelated emissions radiating from the vicinity of the trailing edge. These emissions appear to be the result of acoustic energy radiation which has been converted by the trailing-edge noise mechanism from the dynamic fluid energy of independent streamwise 'strips' of the turbulent boundary layer flow.

Manley, M. B.

1980-01-01

376

Initial development of the two-dimensional ejector shear layer - Experimental results  

NASA Technical Reports Server (NTRS)

An experimental investigation designed to study the development of shear layers in a two-dimensional single-nozzle ejector has been completed. In this study, combinations of air/air, argon/air, helium/air, and air/helium were used as the supersonic primary and subsonic secondary, respectively. Mixing of the gases occurred in a constant-area tube 39.1 mm high by 25.4 mm wide, where the inlet static pressure was maintained at 35 kPa. The cases studied resulted in convective Mach numbers between 0.058 and 1.64, density ratios between 0.102 and 3.49, and velocity ratios between 0.065 and 0.811. The resulting data shows the differences in the shear-layer development for the various combinations of independent variables utilized in the investigation. The normalized growth-rates in the near-field were found to be similar to two-dimensional mixing layers. These results have enhanced the ability to analyze and design ejector systems as well as providing a better understanding of the physics.

Benjamin, M. A.; Dufflocq, M.; Roan, V. P.

1993-01-01

377

Comparison Between Numerical and Experimental Results on Mechanical Stirrer and Bubbling in a Cylindrical Tank - 13047  

SciTech Connect

The process of vitrification in a cold crucible heated by direct induction is used in the fusion of oxides. Its feature is the production of high-purity materials. The high-level of purity of the molten is achieved because this melting technique excludes the contamination of the charge by the crucible. The aim of the present paper is to analyze the hydrodynamic of the vitrification process by direct induction, with the focus in the effects associated with the interaction between the mechanical stirrer and bubbling. Considering the complexity of the analyzed system and the goal of the present work, we simplified the system by not taking into account the thermal and electromagnetic phenomena. Based in the concept of hydraulic similitude, we performed an experimental study and a numerical modeling of the simplified model. The results of these two studies were compared and showed a good agreement. The results presented in this paper in conjunction with the previous work contribute to a better understanding of the hydrodynamics effects resulting from the interaction between the mechanical stirrer and air bubbling in the cold crucible heated by direct induction. Further works will take into account thermal and electromagnetic phenomena in the presence of mechanical stirrer and air bubbling. (authors)

Lima da Silva, M.; Sauvage, E.; Brun, P. [CEA-Marcoule, BP 17171, 30207 Bagnols sur Ceze (France)] [CEA-Marcoule, BP 17171, 30207 Bagnols sur Ceze (France); Gagnoud, A.; Fautrelle, Y. [SIMaP, Grenoble INP, UJF, CNRS, BP 75, 38402 Saint Martin D'Heres (France)] [SIMaP, Grenoble INP, UJF, CNRS, BP 75, 38402 Saint Martin D'Heres (France); Riva, R. [CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble (France)] [CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble (France)

2013-07-01

378

Optimal placement of piezoelectric plates for active vibration control of gas turbine blades: experimental results  

NASA Astrophysics Data System (ADS)

It is well known that the gas turbine blade vibrations can give rise to catastrophic failures and a reduction of the blades life because of fatigue related phenomena[1]-[3] . In last two decades, the adoption of piezoelectric elements, has received considerable attention by many researcher for its potential applicability to different areas of mechanical, aerospace, aeronautical and civil engineering. Recently, a number of studies of blades vibration control via piezoelectric plates and patches have been reported[4]-[6] . It was reported that the use of piezoelectric elements can be very effective in actively controlling vibrations. In one of their previous contributions[7] , the authors of the present manuscript studied a model to control the blade vibrations by piezoelectric elements and validated their results using a multi-physics finite elements package (COMSOL) and results from the literature. An optimal placement method of piezoelectric plate has been developed and applied to different loading scenarios for realistic configurations encountered in gas turbine blades. It has been demonstrated that the optimal placement depends on the spectrum of the load, so that segmented piezoelectric patches have been considered and, for different loads, an optimal combination of sequential and/or parallel actuation and control of the segments has been studied. In this paper, an experimental investigation carried out by the authors using a simplified beam configuration is reported and discussed. The test results obtained by the investigators are then compared with the numerical predictions [7] .

Botta, F.; Marx, N.; Gentili, S.; Schwingshackl, C. W.; Di Mare, L.; Cerri, G.; Dini, D.

2012-04-01

379

Experimental ocean acidification alters the allocation of metabolic energy.  

PubMed

Energy is required to maintain physiological homeostasis in response to environmental change. Although responses to environmental stressors frequently are assumed to involve high metabolic costs, the biochemical bases of actual energy demands are rarely quantified. We studied the impact of a near-future scenario of ocean acidification [800 µatm partial pressure of CO2 (pCO2)] during the development and growth of an important model organism in developmental and environmental biology, the sea urchin Strongylocentrotus purpuratus. Size, metabolic rate, biochemical content, and gene expression were not different in larvae growing under control and seawater acidification treatments. Measurements limited to those levels of biological analysis did not reveal the biochemical mechanisms of response to ocean acidification that occurred at the cellular level. In vivo rates of protein synthesis and ion transport increased ?50% under acidification. Importantly, the in vivo physiological increases in ion transport were not predicted from total enzyme activity or gene expression. Under acidification, the increased rates of protein synthesis and ion transport that were sustained in growing larvae collectively accounted for the majority of available ATP (84%). In contrast, embryos and prefeeding and unfed larvae in control treatments allocated on average only 40% of ATP to these same two processes. Understanding the biochemical strategies for accommodating increases in metabolic energy demand and their biological limitations can serve as a quantitative basis for assessing sublethal effects of global change. Variation in the ability to allocate ATP differentially among essential functions may be a key basis of resilience to ocean acidification and other compounding environmental stressors. PMID:25825763

Pan, T-C Francis; Applebaum, Scott L; Manahan, Donal T

2015-04-14

380

Experimental ocean acidification alters the allocation of metabolic energy  

PubMed Central

Energy is required to maintain physiological homeostasis in response to environmental change. Although responses to environmental stressors frequently are assumed to involve high metabolic costs, the biochemical bases of actual energy demands are rarely quantified. We studied the impact of a near-future scenario of ocean acidification [800 µatm partial pressure of CO2 (pCO2)] during the development and growth of an important model organism in developmental and environmental biology, the sea urchin Strongylocentrotus purpuratus. Size, metabolic rate, biochemical content, and gene expression were not different in larvae growing under control and seawater acidification treatments. Measurements limited to those levels of biological analysis did not reveal the biochemical mechanisms of response to ocean acidification that occurred at the cellular level. In vivo rates of protein synthesis and ion transport increased ?50% under acidification. Importantly, the in vivo physiological increases in ion transport were not predicted from total enzyme activity or gene expression. Under acidification, the increased rates of protein synthesis and ion transport that were sustained in growing larvae collectively accounted for the majority of available ATP (84%). In contrast, embryos and prefeeding and unfed larvae in control treatments allocated on average only 40% of ATP to these same two processes. Understanding the biochemical strategies for accommodating increases in metabolic energy demand and their biological limitations can serve as a quantitative basis for assessing sublethal effects of global change. Variation in the ability to allocate ATP differentially among essential functions may be a key basis of resilience to ocean acidification and other compounding environmental stressors. PMID:25825763

Pan, T.-C. Francis; Applebaum, Scott L.; Manahan, Donal T.

2015-01-01

381

Experimental Results and Predictive Calculations for Pinhole Collimators Used in Small Animal Nuclear Imaging*  

NASA Astrophysics Data System (ADS)

Biological ligands tagged with ^125 I have been used in studies including comparisons between normal and diabetic mice in vivo. In order to enhance the image of the mouse pancreas we have tested a number of pinhole collimators coupled to two types of position sensitive photomultiplier tube. Various shapes of pinhole have been tested. Results will be described and discussed. *Supported in part by The Department of Energy, The National Science Foundation, The American Diabetes Association, The Howard Hughes Foundation, The Virginia Commonwealth Health Research Board and the Thomas F. and Kate Miller Jeffress Memorial Trust.

Ng, Luke; Welsh, Robert E.; Bradley, Eric L.; Saha, Margaret S.; Kross, Brian; Majewski, Stan; Popov, Vladimir; Smith, Mark F.; Weisenberger, Andrew G.; Wojcik, Randolph

2001-04-01

382

Responses of Tundra Ecosystems to Environmental Change: Observational and Experimental Results  

NASA Astrophysics Data System (ADS)

Evidence of environmental changes due to human-enhanced climate warming continues to accumulate from polar regions. Responses in tundra and taiga ecosystems to climate changes have been variable because of the wide range in process response rates, from metabolic processes to adjustments in ecosystem carbon balance, and the variability in environmental settings across local to regional scales. For example, strong increases in rates of plant growth and changes in species composition and abundance have been observed in parts of the Low Arctic, but very little change has been measured in high arctic tundra. A dramatic increase in the cover of deciduous shrubs in areas of the western North American Arctic is predicted to result in positive feedbacks to soil temperature, through increased surface roughness and snow depth, and to atmospheric heating by reducing albedo. Increased shrub cover has also been found in long-term experimental warming studies conducted throughout the tundra biome as part of the International Tundra Experiment (ITEX). Warming is also affecting the carbon balance of tundra and taiga, which hold 25% of the soil carbon of global terrestrial ecosystems. However, trajectories of these changes are largely unknown for most northern systems, and differ because of initial conditions of the carbon and nutrient economy. Over the longer-term, the positive increases in plant growth may be constrained by negative feedbacks to nutrient cycling, as increases in C:N ratios of plant litter slow the release of nitrogen to soils. However, nitrogen availability has been shown to increase in response to short-term warming. In this presentation, I will review the responses of tundra ecosystems to climate variability and change, both through observational and experimental studies.

Henry, G. H.

2004-05-01

383

Soft material adhesion characterization for in vivo locomotion of robotic capsule endoscopes: Experimental and modeling results.  

PubMed

The objective of this work is to validate an experimental method and nondimensional model for characterizing the normal adhesive response between a polyvinyl chloride based synthetic biological tissue substrate and a flat, cylindrical probe with a smooth polydimethylsiloxane (PDMS) surface. The adhesion response is a critical mobility design parameter of a Robotic Capsule Endoscope (RCE) using PDMS treads to provide mobility to travel through the gastrointestinal tract for diagnostic purposes. Three RCE design characteristics were chosen as input parameters for the normal adhesion testing: pre-load, dwell time and separation rate. These parameters relate to the RCE?s cross sectional dimension, tread length, and tread speed, respectively. An inscribed central composite design (CCD) prescribed 34 different parameter configurations to be tested. The experimental adhesion response curves were nondimensionalized by the maximum stress and total displacement values for each test configuration and a mean nondimensional curve was defined with a maximum relative error of 5.6%. A mathematical model describing the adhesion behavior as a function of the maximum stress and total displacement was developed and verified. A nonlinear regression analysis was done on the maximum stress and total displacement parameters and equations were defined as a function of the RCE design parameters. The nondimensional adhesion model is able to predict the adhesion curve response of any test configuration with a mean R(2) value of 0.995. Eight additional CCD studies were performed to obtain a qualitative understanding of the impact of tread contact area and synthetic material substrate stiffness on the adhesion response. These results suggest that the nondimensionalization technique for analyzing the adhesion data is sufficient for all values of probe radius and substrate stiffness within the bounds tested. This method can now be used for RCE tread design optimization given a set of environmental conditions for device operation. PMID:25151447

Kern, Madalyn D; Ortega Alcaide, Joan; Rentschler, Mark E

2014-11-01

384

Electrostatic binding of proteins to membranes. Theoretical predictions and experimental results with charybdotoxin and phospholipid vesicles.  

PubMed Central

We previously applied the Poisson-Boltzmann equation to atomic models of phospholipid bilayers and basic peptides to calculate their electrostatic interactions from first principles (Ben-Tal, N., B. Honig, R. M. Peitzsch, G. Denisov, and S. McLaughlan. 1996. Binding of small basic peptides to membranes containing acidic lipids. Theoretical models and experimental results. Biophys. J. 71:561-575). Specifically, we calculated the molar partition coefficient, K (the reciprocal of the lipid concentration at which 1/2 the peptide is bound), of simple basic peptides (e.g., pentalysine) with phospholipid vesicles. The theoretical predictions agreed well with experimental measurements of the binding, but the agreement could have been fortuitous because the structure(s) of these flexible peptides is not known. Here we use the same theoretical approach to calculate the membrane binding of two small proteins of known structure: charybdotoxin (CTx) and iberiotoxin (IbTx); we also measure the binding of these proteins to phospholipid vesicles. The theoretical model describes accurately the dependence of K on the ionic strength and mol % acidic lipid in the membrane for both CTx (net charge +4) and IbTx (net charge +2). For example, the theory correctly predicts that the value of K for the binding of CTx to a membrane containing 33% acidic lipid should decrease by a factor of 10(5) when the salt concentration increases from 10 to 200 mM. We discuss the limitations of the theoretical approach and also consider a simple extension of the theory that incorporates nonpolar interactions. Images FIGURE 1 FIGURE 4 PMID:9336168

Ben-Tal, N; Honig, B; Miller, C; McLaughlin, S

1997-01-01

385

Beryllium metal I. experimental results on acute oral toxicity, local skin and eye effects, and genotoxicity.  

PubMed

The toxicity of soluble metal compounds is often different from that of the parent metal. Since no reliable data on acute toxicity, local effects, and mutagenicity of beryllium metal have ever been generated, beryllium metal powder was tested according to the respective Organisation for Economical Co-Operation and Development (OECD) guidelines. Acute oral toxicity of beryllium metal was investigated in rats and local effects on skin and eye in rabbits. Skin-sensitizing properties were investigated in guinea pigs (maximization method). Basic knowledge about systemic bioavailability is important for the design of genotoxicity tests on poorly soluble substances. Therefore, it was necessary to experimentally compare the capacities of beryllium chloride and beryllium metal to form ions under simulated human lung conditions. Solubility of beryllium metal in artificial lung fluid was low, while solubility in artificial lysosomal fluid was moderate. Beryllium chloride dissolution kinetics were largely different, and thus, metal extracts were used in the in vitro genotoxicity tests. Genotoxicity was investigated in vitro in a bacterial reverse mutagenicity assay, a mammalian cell gene mutation assay, a mammalian cell chromosome aberration assay, and an unscheduled DNA synthesis (UDS) assay. In addition, cell transformation was tested in a Syrian hamster embryo cell assay, and potential inhibition of DNA repair was tested by modification of the UDS assay. Beryllium metal was found not to be mutagenic or clastogenic based on the experimental in vitro results. Furthermore, treatment with beryllium metal extracts did not induce DNA repair synthesis, indicative of no DNA-damaging potential of beryllium metal. A cell-transforming potential and a tendency to inhibit DNA repair when the cell is severely damaged by an external stimulus were observed. Beryllium metal was also found not to be a skin or eye irritant, not to be a skin sensitizer, and not to have relevant acute oral toxic properties. PMID:21196457

Strupp, Christian

2011-01-01

386

Computational modeling of stationary gastungsten-arc weld pools and comparison to stainless steel 304 experimental results  

Microsoft Academic Search

A systematic study was carried out to verify the predictions of a transient multidimensional computational model by comparing\\u000a the numerical results with the results of an experimental study. The welding parameters were chosen such that the predictions\\u000a of the model could be correlated with the results of an earlier experimental investigation of the weld pool surface temperatures\\u000a during spot gas-tungsten-arc

T. Zacharia; S. A. David; J. M. Vitek; H. G. Kraus

1991-01-01

387

Results on the energy dependence of cosmic ray charge composition  

NASA Technical Reports Server (NTRS)

Measurements using a balloon-borne ionization spectrometer on the differential energy spectra of the heavy nuclei of the galactic cosmic radiation are reported. The spectra of individual elements up to oxygen and groups of nuclei up through iron were measured up to almost 100 GeV/nucleon. The energy spectrum of the secondary nuclei, B+N, is steeper than that of the primary nuclei, C+O, by gamma = 0.21 + or - .09 in agreement with other authors. The spectral shapes found are reasonably well represented by single power laws between 2 and 60 GeV/nucleon. Data are consistent with the decrease in the secondary to primary ratio found by others above 20 GeV/nucleon, but it shows no evidence for any sudden change in this ratio within counting statistics. The most dramatic finding is that the spectrum of the iron nuclei is flatter than that of the carbon and oxygen nuclei by 0.57 + or - 0.14 of a power. The experimental techniques for charge and energy determination are presented and corrections due to nuclear disintegration and losses of energy out the bottom of the spectrometer are discussed.

Balasubrahmanyan, V. K.; Ormes, J. F.

1973-01-01

388

Experimental Free Energy Surface Reconstruction From Single-Molecule Force Spectroscopy Using Jarzynski's Equality  

E-print Network

We used the atomic force microscope to manipulate and unfold individual molecules of the titin I27 domain and reconstructed its free energy surface using Jarzynski's equality. The free energy surface for both stretching and unfolding was reconstructed using an exact formula that relates the nonequilibrium work fluctuations to the molecular free energy. In addition, the unfolding free energy barrier, i.e. the activation energy, was directly obtained from experimental data for the first time. This work demonstrates that Jarzynski's equality can be used to analyze nonequilibrium single-molecule experiments, and to obtain the free energy surfaces for molecular systems, including interactions for which only nonequilibrium work can be measured.

Nolan C. Harris; Yang Song; Ching-Hwa Kiang

2007-07-03

389

COMPARISON OF EXPERIMENTAL RESULTS TO CFD MODELS FOR BLENDING IN A TANK USING DUAL OPPOSING JETS  

SciTech Connect

Research has been completed in a pilot scale, eight foot diameter tank to investigate blending, using a pump with dual opposing jets. The jets re-circulate fluids in the tank to promote blending when fluids are added to the tank. Different jet diameters and different horizontal and vertical orientations of the jets were investigated. In all, eighty five tests were performed both in a tank without internal obstructions and a tank with vertical obstructions similar to a tube bank in a heat exchanger. These obstructions provided scale models of several miles of two inch diameter, serpentine, vertical cooling coils below the liquid surface for a full scale, 1.3 million gallon, liquid radioactive waste storage tank. Two types of tests were performed. One type of test used a tracer fluid, which was homogeneously blended into solution. Data were statistically evaluated to determine blending times for solutions of different density and viscosity, and the blending times were successfully compared to computational fluid dynamics (CFD) models. The other type of test blended solutions of different viscosity. For example, in one test a half tank of water was added to a half tank of a more viscous, concentrated salt solution. In this case, the fluid mechanics of the blending process was noted to significantly change due to stratification of fluids. CFD models for stratification were not investigated. This paper is the fourth in a series of papers resulting from this research (Leishear, et.al. [1- 4]), and this paper documents final test results, statistical analysis of the data, a comparison of experimental results to CFD models, and scale-up of the results to a full scale tank.

Leishear, R.

2011-08-07

390

A comparison of the theoretical and experimental results for keV electron scattering from argon  

NASA Astrophysics Data System (ADS)

Experiments studying the scattering of keV electrons from noble gas atoms have been performed in the past, as the first Born approximation (FBA) was thought to be valid under these conditions, and hence it was expected that these experiments could be modelled relatively straightforwardly by theory. Somewhat surprisingly these experiments have so far attracted only very limited theoretical interest and the ability of modern scattering theory to describe them has not been firmly established. In our earlier study of the cross section for the resonant transitions, we established that the FBA was sufficient to describe the results for small scattering angles, but it did not account for the observed intensity at larger angles. Here we extend this comparison for the case of argon to monopole, quadrupole and octopole transitions below the continuum. The experimental results show differential cross sections spanning many orders of magnitude for these transitions. The relativistic distorted wave theory developed here describes these experiments for many transitions and a large range of scattering angles reasonably well.

Vos, M.; McEachran, R. P.; Zhu, Lin-Fan

2014-03-01

391

Thermal Conductivity of Amorphous Geomaterials at Magmatic Temperatures: Review, Theory, and New Experimental Results.  

NASA Astrophysics Data System (ADS)

Of all the transport properties of silicate melts and glasses, thermal conductivity remains the most poorly known despite its significance regarding both the transport of heat between magma and its surroundings and the petrologic evolution of open magmatic systems. The dearth of experimental conductivity data arises from the intrinsic difficulty of the experiments due to the confounding effects of convective heat transport and radiative transport, the latter which becomes important at high temperature (T). Although the volumetric absorption of radiation can be treated using the extinction coefficient, ?ex, defined as the inverse of the photon mean-free path, lph, the simultaneous treatment of the absorption, emission and scattering of radiation in a nonisothermal experiment may be complex. Additional complexity arises due to the dependence of lph on wavelength, ? . For example, for low-FeO silicate glass, lph = 0.2 m (?ex \\approx 5 m-1) at \\lambda = 0.4 ?m, whereas for \\lambda = 8 ?m, lph = 0.002 m (?ex \\approx 500 m-1). In natural systems, the optical thickness, ?OT \\equiv ?exL is large and the `thick-medium' approximation is justified since ?OT >> 1. Under this assumption the radiant conductivity (kR = 16/3\\sigmaSBn2T3lph) may be defined where the radiant heat flux is proportional to the temperature gradient as is the case for phonon conduction. We have undertaken a critical compilation of experimental results in order to separate the effects of the radiant (kR) and phonon (kP) conductivity in amorphous (molten and glassy) silicates and to understand the role of structural disorder on phonon conductivity. Because the radiative conductivity (kR) is ~ T3, experimental values of the `apparent' or `total' thermal conductivity (kT = kR + kP) plotted against T3 enable one to separate approximately the effects of radiation from phonon conduction in some instances. This approach enables one to estimate wavelength integrated extinction coefficients since the radiative heat flux is inversely proportional to the mean (wave-length integrated) extinction coefficient. In contrast, the phonon conductivity (kP) derives from two sources: phonon interaction and scattering due to structural disorder. Above the Debye temperature, Cp of a melt is constant; kp is ~ to the mean free path between atomic collisions (? ) which in turn varies inversely to the number of excited phonons (~ T). Hence, kP ~ 1/T. Near the Debye temperature, Cp decreases as T decreases and kP is less than expected from 1/T dependence. At very low temperature, even though few phonons are excited ? does not increase without limit because of structural disorder. Additionally, Cp ~ T3 and so kP is an increasing function of T. Finally, we present new experimental measurements of the thermal conductivity for supercooled amorphous geomaterials using a transient method and minimize radiant conductive effects using large volume (5x10-5 m3) samples (L ~0.04 m). The radiant contribution to the thermal conductivity is small in this apparatus for liquids characterized by mean (wave-length integrated) extinction coefficients > ~200 m-1.

Zayac, J. M.; Spera, F. J.

2002-12-01

392

Experimental Study on the Energy Consumption in IaaS Cloud Environments  

E-print Network

Experimental Study on the Energy Consumption in IaaS Cloud Environments Alexandra Carpen in Infrastructure-as-a-Service (IaaS) environments. Our main contribution is twofold. First, we provide an evaluation of two well known IaaS cloud platforms with respect to energy consumption. Second, we study

Paris-Sud XI, Université de

393

Experimental Testing and Model Validation for Ocean Wave Energy Harvesting Buoys  

E-print Network

Experimental Testing and Model Validation for Ocean Wave Energy Harvesting Buoys Douglas A. Gemme1 are presented for numerical simulations and field experiments using point absorption ocean wave energy for large scale grid power applications, but rather for relatively low-power ocean sensor and communications

Grilli, Stéphan T.

394

Experimental investigation of manned vehicle utilizing CDE (concentration difference energy) engine  

SciTech Connect

In this paper, the recent development of thermal energy storage and heat transfer equipment with the strong water lithium salts solution is presented. About 40% of the theoretical energy storage capacity is liberated from this experimental apparatus. The characteristic of heat transfer in absorbing steam generators obtain very high absorbing heat transfer coefficiens, and, therefore, high efficiency of travelling performance is obtained. 4 refs.

Kamoshida, J.; Isshiki, N.

1981-01-01

395

An Experimental Study of Shape Transitions and Energy Scaling in Thin Non-Euclidean Plates  

E-print Network

dimensional (2D) geometry of the mid surface of these sheets is non-Euclidean. The laterally nonAn Experimental Study of Shape Transitions and Energy Scaling in Thin Non- Euclidean Plates Yael study of shape and energy scaling in non-Euclidean plates. Using environmentally responsive gel discs

Venkataramani, Shankar C.

396

Drying of porous media in the presence of gravity: Experimental Results and Pore Network Modeling  

NASA Astrophysics Data System (ADS)

We study the drying of glass bead packings saturated with liquid hexane in predominantly 2D glass cells under environmental conditions to offer insight in the dynamics of the drying process. Our experimental setup allows for the monitoring of the bulk liquid and gas phase distribution patterns, as well as the liquid films that form at the pore walls after the invasion of the bulk gas phase. We are thus able to classify the drying pore space into 3 distinct regions; a far-field completely-wet region, where the pore space is saturated by the bulk liquid hexane; a completely dry region, close to side of the medium open to the ambient environment, that contains only hexane vapors; and finally an intermediate region, located between the first two, that is partially saturated by liquid hexane in the form of liquid films at the walls of the pores and by hexane vapors in the central part of the pore space. Our experiments reveal two distinct drying periods; an early constant drying rate period (CRP), that lasts as long as the film region is contact with the external surface of the medium; and a later falling rate period (FRP) that is related with the development of the completely dry region below the surface. The critical residual hexane saturation that marks the transition between these two regimes is found to be a function of the average bead size in our packings and the incline of the cells with respect to the flat surface, with larger beads and angles closer to the vertical position leading to earlier film detachment times and higher critical saturations. Based on our experimental results we propose a pore network model that accounts for the major transport mechanisms within the porous medium coupled with mass transfer by diffusion through a mass boundary layer over the external surface of the medium. We show that in the limit of a gravity-stabilized percolation front (interface between the completely-wet and film regions) the medium can be treated as a 1D continuum where analytical solutions to the governing equations are derived. We are thus able to obtain results for the drying rates, the critical saturation and the extent of the film region with respect to the various dimensionless numbers that describe the process; the Bond number, a film-based Capillary number and the dimensionless extent of the mass boundary layer.

Yiotis, A. G.; Salin, D.; Tajer, E.; Yortsos, Y.

2011-12-01

397

Experimental Energy Levels of HD18O and D_218O  

NASA Astrophysics Data System (ADS)

Extended sets of experimental energy levels of HD18O and D_218O have been obtained as the result of the analysis of recent high-resolution spectra and previously reported data. Spectra of the enriched by deuterium and oxygen-18 water samples were recorded with a Bruker IFS 120HR spectrometer at room temperature in the 1000 - 9200 cm-1 range a,b for this purpose. The RITZ code h was used for analysis of the rotation-vibration transitions and the energy levels determination. New energy levels as well as comparison with previous experimental and theoretical studies will be presented. This work was supported by Grant nos. 06-03-39014 and 10-05-91176 of RFBR (Russia) and by Grant nos. 20903085 and 10574124 of NSFC (China). Work of SNM and SAT was also partly supported by CRDF (USA) Grant RUG1-2954-TO-09 and by RFBR. Grant 09-05-92508. A.-W. Liu et al., J. Mol. Spectrosc. 237, 149-162 (2006). H.-Y. Ni et al., Mol. Phys. 106, 1793-1801 (2008). J. Bellet et al., J. Mol. Spectrosc. 47, 388-402 (1973). J.W.C. Johns, J. Opt. Soc. Am. B2, 1340-1354 (1985). R.A. Toth, J. Mol. Spectrosc. 162, 41-54 (1993). W.F. Wang et al., J. Mol. Spectrosc. 176, 226-228 (1996). R.A. Toth, J. Mol. Structure, 742, 49-68 (2005). S.N. Mikhailenko et al., JQSRT, 110, 597-608 (2009). A. Liu et al., JQSRT, 110, 1781-1800 (2009). O.V. Naumenko et al., JQSRT, 111, 36-44 (2010).

Mikhailenko, S. N.; Naumenko, O. V.; Tashkun, S. A.; Liu, A.-W.; Hu, S.-M.

2010-06-01

398

Modal characterization of the ASCIE segmented optics testbed: New algorithms and experimental results  

NASA Technical Reports Server (NTRS)

New frequency response measurement procedures, on-line modal tuning techniques, and off-line modal identification algorithms are developed and applied to the modal identification of the Advanced Structures/Controls Integrated Experiment (ASCIE), a generic segmented optics telescope test-bed representative of future complex space structures. The frequency response measurement procedure uses all the actuators simultaneously to excite the structure and all the sensors to measure the structural response so that all the transfer functions are measured simultaneously. Structural responses to sinusoidal excitations are measured and analyzed to calculate spectral responses. The spectral responses in turn are analyzed as the spectral data become available and, which is new, the results are used to maintain high quality measurements. Data acquisition, processing, and checking procedures are fully automated. As the acquisition of the frequency response progresses, an on-line algorithm keeps track of the actuator force distribution that maximizes the structural response to automatically tune to a structural mode when approaching a resonant frequency. This tuning is insensitive to delays, ill-conditioning, and nonproportional damping. Experimental results show that is useful for modal surveys even in high modal density regions. For thorough modeling, a constructive procedure is proposed to identify the dynamics of a complex system from its frequency response with the minimization of a least-squares cost function as a desirable objective. This procedure relies on off-line modal separation algorithms to extract modal information and on least-squares parameter subset optimization to combine the modal results and globally fit the modal parameters to the measured data. The modal separation algorithms resolved modal density of 5 modes/Hz in the ASCIE experiment. They promise to be useful in many challenging applications.

Carrier, Alain C.; Aubrun, Jean-Noel

1993-01-01

399

Experimental and theoretical study of the energy loss of Be and B ions in Zn  

NASA Astrophysics Data System (ADS)

Energy-loss measurements and theoretical calculations for Be and B ions in Zn are presented. The experimental ion energies range from 40 keV/u to 1 MeV/u, which includes the energy-loss maximum and covers a lack of experimental data for these systems from intermediate to high energies. The measurements were performed using the Rutherford backscattering technique. The ab initio calculations are based on the extended Friedel sum rule-transport cross-section method for the valence electrons and the Shellwise local plasma approximation for the bound electrons. A comparison of these calculations to the present experimental data for Be and B and previous values for H, He, and Li ions on the same target is included. This confirms the applicability of the employed theoretical framework also for ions of intermediate atomic number.

Cantero, E. D.; Fadanelli, R. C.; Montanari, C. C.; Behar, M.; Eckardt, J. C.; Lantschner, G. H.; Miraglia, J. E.; Arista, N. R.

2009-04-01

400

Kentucky's Experimental Elementary Counselor Program: Results and Recommendations for Marketing Exemplary Practices To Meet KERA Goals.  

ERIC Educational Resources Information Center

This report examines Kentucky's experimental elementary guidance programs, which were funded in 1988 and evaluated in the second year of the 2-year experimental program. In the second year, data were gathered from counselors, teachers, students, and parents; the data are presented in this document. The first section, "Effective Elementary Guidance…

Holcomb, Thomas F.; Latto, Lowell D.

401

Exchange bias in core\\/shell magnetic nanoparticles: experimental results and numerical simulations  

Microsoft Academic Search

In this talk, we will review some of the main experimental observations related to the occurrence of exchange bias in magnetic systems, focusing the attention on the phenomenology appearing in nanoparticles with core\\/shell structure as compared to thin film bilayers [1]. The main open questions posed by the experimental observations will be discussed and contrasted to existing theories and models

Xavier Batlle

2009-01-01

402

A design and experimental verification methodology for an energy harvester skin structure  

NASA Astrophysics Data System (ADS)

This paper presents a design and experimental verification methodology for energy harvesting (EH) skin, which opens up a practical and compact piezoelectric energy harvesting concept. In the past, EH research has primarily focused on the design improvement of a cantilever-type EH device. However, such EH devices require additional space for proof mass and fixture and sometimes result in significant energy loss as the clamping condition becomes loose. Unlike the cantilever-type device, the proposed design is simply implemented by laminating a thin piezoelectric patch onto a vibrating structure. The design methodology proposed, which determines a highly efficient piezoelectric material distribution, is composed of two tasks: (i) topology optimization and (ii) shape optimization of the EH material. An outdoor condensing unit is chosen as a case study among many engineered systems with harmonic vibrating configuration. The proposed design methodology determined an optimal PZT material configuration on the outdoor unit skin structure. The designed EH skin was carefully prototyped to demonstrate that it can generate power up to 3.7 mW, which is sustainable for operating wireless sensor units for structural health monitoring and/or building automation.

Lee, Soobum; Youn, Byeng D.

2011-05-01

403

New experimental study of low-energy (p,gamma) resonances in magnesium isotopes  

E-print Network

Proton captures on Mg isotopes play an important role in the Mg-Al cycle active in stellar H shell burning. In particular, the strengths of low-energy resonances with E < 200 keV in 25Mg(p,gamma)26Al determine the production of 26Al and a precise knowledge of these nuclear data is highly desirable. Absolute measurements at such low-energies are often very difficult and hampered by gamma-ray background as well as changing target stoichiometry during the measurements. The latter problem can be partly avoided using higher energy resonances of the same reaction as a normalization reference. Hence the parameters of suitable resonances have to be studied with adequate precision. In the present work we report on new measurements of the resonance strengths omega_gamma of the E = 214, 304, and 326 keV resonances in the reactions 24Mg(p,gamma)25Al, 25Mg(p,gamma)26Al, and 26Mg(p,gamma)27Al, respectively. These studies were performed at the LUNA facility in the Gran Sasso underground laboratory using multiple experimental techniques and provided results with a higher accuracy than previously achieved.

B. Limata; F. Strieder; A. Formicola; G. Imbriani; M. Junker; H. W. Becker; D. Bemmerer; A. Best; R. Bonetti; C. Broggini; A. Caciolli; P. Corvisiero; H. Costantini; A. DiLeva; Z. Elekes; Zs. Fülöp; G. Gervino; A. Guglielmetti; C. Gustavino; Gy. Gyürky; A. Lemut; M. Marta; C. Mazzocchi; R. Menegazzo; P. Prati; V. Roca; C. Rolfs; C. Rossi Alvarez; C. Salvo; E. Somorjai; O. Straniero; F. Terrasi; H. -P. Trautvetter

2010-06-28

404

Experimental Performance Analysis of Supercritical CO2 Thermodynamic Cycle Powered by Solar Energy  

NASA Astrophysics Data System (ADS)

The interests in using carbon dioxide as working fluid increase since the Montreal and Kyoto Protocols were made. In this paper, a complete effort was made to study the performance of CO2 Rankine cycle powered by solar energy experimentally. The system utilizes evacuated solar collectors to convert CO2 into high-temperature supercritical state, used to produce electrical energy and thermal energy, which could be used for air conditioning and hot water supply and so on. The system performances were tested not only in summer, but also in winter; not only in sunny day, but also in cloudy day. The interest of the paper is the solar collector efficiency, because the absorbed heat quantity in the collector can be utilized for power generation and heat supply and other useful outputs. The results show that annually-averaged solar collector efficiency was measured at about 60.4%. The study shows the potential of the application of the solar powered CO2 cycle as a distributed power/heat generation system.

Zhang, X. R.; Yamaguchi, H.; Fujima, K.; Enomoto, M.; Sawada, N.

2006-05-01

405

Experimental and analytical results of a liquid-gas separator in microgravity  

NASA Astrophysics Data System (ADS)

The microgravity phase separator designed and fabricated at Texas A&M University relies on centripetally driven buoyancy forces to form a gas-liquid vortex within a fixed, right-circular cylinder. Two phase flow is injected tangentially along the inner wall of this cylinder. Centripetal acceleration is produced from the intrinsic momentum of the resulting rotating flow and drives the buoyancy process. Gas travels under density gradients through the rotating liquid, eventually forming a gaseous core along the centerline of the cylinder. Gas core stability, the presence of liquid in the air line, and the presence of air in the liquid line determine whether a successful core results. To predict separation failure, these three factors were examined both analytically and empirically with the goal of determining what operating circumstances would generate them. The centripetal acceleration profile was determined from angular velocity measurements taken using a paddle wheel assembly. To aid in understanding the nature of the rotating flow, these results were compared to analytical results provided by solving simplified Navier-Stokes equations. The theoretical velocity profile indicated a linear dependence on radius, which with the experimental data agreed, although two distinctly different slopes were observed. As injection nozzle width increased, the difference between the slopes lessened. For all three nozzles tested, the discontinuity between the linear sections occurred at a radius of approximately 3.8 cm. The maximum centripetal acceleration generated by the flow was greatest for the 0.0635 cm wide, 0.516 cm tall injection nozzle and least for the 0.102 cm wide, 1.02 cm tall injection nozzle. The circumstances leading to carry-under are dictated by the relationship between axial and radial bubble transit times. To determine the radial and axial transit times, the radial velocity profile was solved analytically by relating the buoyancy and drag forces for a 0.0635 cm radius bubble. This velocity profile was then used to produce a numerical solution for the radial transit time. Volumetric flowrate analysis provided the axial velocity and bubble transit time. 33.4, 50.1, 66.8, and 83.5 cm3/s flowrates were tested and only the 33.4 cm3/s flowrate resulted in conditions which would lead to carry under.

Best, Frederick; Ellis, Michael

1999-01-01

406

Patient-cooperative strategies for robot-aided treadmill training: first experimental results.  

PubMed

Task-oriented repetitive movements can improve motor performance in patients with neurological or orthopaedic lesions. The application of robotics and automation technology can serve to assist, enhance, evaluate, and document neurological and orthopedic rehabilitation. This paper deals with the application of "patient-cooperative" techniques to robot-aided gait rehabilitation of neurological disorders. We define patient-cooperative to mean that, during movement, the technical system takes into account the patient's intention and voluntary efforts rather than imposing any predefined movements or inflexible strategies. It is hypothesized that such cooperative robotic approaches can improve the therapeutic outcome compared to classical rehabilitation strategies. New cooperative strategies are presented that detect the patient's voluntary efforts. First, this enables the patient increased freedom of movement by a certain amount of robot compliance. Second, the robot behavior adapts to the existing voluntary motor abilities. And third, the robotic system displays and improves the patient contribution by visual biofeedback. Initial experimental results are presented to evaluate the basic principle and technical function of proposed approaches. Further improvements of the technical design and additional clinical testing is required to prove whether the therapeutic outcome can be enhanced by such cooperative strategies. PMID:16200761

Riener, Robert; Lünenburger, Lars; Jezernik, Saso; Anderschitz, Martin; Colombo, Gery; Dietz, Volker

2005-09-01

407

First Experimental Results with a New Type of Stent: The Double-Coil Device  

SciTech Connect

Purpose: To introduce a new stent design and evaluate its technical properties. Methods: This stent consists of two nitinol wires partially connected to each other.After delivery through a catheter a tube-like helical stent forms within the artery. After experimental tests in flow models regarding mechanical properties, introduction and delivery technique, 15 stents were implanted into iliac, femoral, and carotid arteries of seven dogs.After 3-12 weeks angiographic follow-up stents were explanted for microscopic examination. Results: Stents with expanded diameters of 5-10 mm can be introduced through a 5 Fr catheter with 0.038 inch luminal diameter. Thrombotic vessel occlusion was observed in one iliac artery after incorrect stent placement with diameter mismatch. Fourteen of 15 stents remained patent and revealed minor intimal hyperplasia in the areas of the stent strut connection points as well as some reduction in medial thickness. Conclusion: This new stent design has a small introduction diameter which is independent of the expanded diameter. The stent's principal characteristics may serve as a basis for further special developments.

Strecker, Ernst-Peter [Diakonissenkrankenhaus Karlsruhe, Diakonissenstrasse 28, D-76199 Karlsruhe, Department of Diagnostic Imaging, Interventional Radiology and Nuclear Medicine (Germany)], E-mail: radiologie@diak-ka.de; Song, Ho-Young; Kang, Sung-Gwon [Asan Medical Center, University of Ulsan College of Medicine, Seoul, Department of Diagnostic Radiology (Korea, Republic of); Hou Dongming [Diakonissenkrankenhaus Karlsruhe, Diakonissenstrasse 28, D-76199 Karlsruhe, Department of Diagnostic Imaging, Interventional Radiology and Nuclear Medicine (Germany); Schumacher, M. [University Clinics Freiburg, Freiburg, Institute of Neuroradiology (Germany)

2003-06-15

408

Experimental Results on the Diffractive Production of Light Vector Mesons at HERA  

E-print Network

We discuss results on the diffractive production of the vector mesons rho, phi and omega reported by the H1 and ZEUS collaborations at HERA. Unique to such studies is the experimental accessibility to the polarization of the vector mesons and hence to the spin-density matrix elements arising in vacuum-exchange processes. We emphasize the relation between the observed dependence on momentum transfer and the polarization state of the vector meson. The diffractive nature of the production mechanism is investigated via extraction of the Pomeron trajectory at high Q^2. Flavor symmetry is observed in the phi/rho ratios in the same region of momentum transfer where the power-law scaling becomes similar. The multivariable helicity analyses impose stringent constraints on models for the vacuum-exchange production mechanism. Semi-exclusive photoproduction of transverse rho and phi mesons at momentum transfers far exceeding their mass scale exhibit a hard scaling behavior which appears to violate the QCD helicity selection rules in a two-gluon exchange model.

J. A. Crittenden; H1 Collaboration; ZEUS Collaboration

2001-10-18

409

[Central pain processing and Parkinson's disease. Epidemiology, physiology, and experimental results issuing pain processing].  

PubMed

Parkinson's disease (PD) is caused by degeneration of the dopaminergic neurons in the substantia nigra (SN) and a resulting dysfunction of the nigrostriatal pathways including the basal ganglia. Beside motor symptoms, different types of pain (e.g., dystonic musculoskeletal pain or central pain) occur in a considerable number of patients. In addition, abnormalities in pain processing have been observed in PD patients, which may present as increased pain sensitivity. The pathophysiological mechanisms involved in disturbed pain processing of PD, however, are still poorly understood. The present article gives an overview of the relevant experimental studies, investigating the abnormalities of pain processing in PD by means of electrophysiological [electroencephalography (EEG), sympathetic skin response (SSR)] and psychophysical methods [quantitative sensory testing (QST), RIII reflex threshold]. Based on a review of the literature, it is postulated that dysfunction in endogenous pain inhibition caused by dopaminergic deficiency in the basal ganglia, especially in the striatum, but also in mesolimbic areas is a main pathophysiological mechanism involved in nociceptive abnormalities in PD. PMID:23052966

Priebe, J A; Rieckmann, P; Lautenbacher, S

2012-12-01

410

Analytical model for a pulse tube cryocooler bellows phase shifter and experimental results  

NASA Astrophysics Data System (ADS)

Losses within a pulse tube cryocooler (PTC) are dominated by regenerator losses that scale directly with the magnitude of the mass flow rate within the regenerator. Therefore, in order to maximize PTC performance it is necessary to minimize the ratio of the mass flow rate in the regenerator to the acoustic power. This is accomplished by controlling the phase between the mass flow and the pressure with a phase shifting device installed at the warm end of the pulse tube. The most common device, the inertance tube, has significant disadvantages including limited achievable phase angles and large mass and volume. Also, once installed the inertance tube is not tunable. It has been proposed that the inertance tube be replaced with a hybrid mechanical/electrical phase shifting system. The damping for this system is provided by an eddy current damper and can be controlled via an applied external magnetic field that provides active real-time phase control. This paper presents an analytical model of a bellows phase shifting mechanism for a PTC. The model is used to determine properties of the phase shifting mechanism (volume, mass, spring constant, damping force, etc.) based on typical PTC operating conditions. Initial experimental results are also presented.

Cheadle, Michael; Nellis, Gregory; Klein, Sanford

2012-06-01

411

A new mechanical device for circular compression anastomosis. Preliminary results of animal and clinical experimentation.  

PubMed Central

The authors report the preliminary results obtained in animal and clinical experimentation of a new mechanical device for circular anastomosis which they have developed. It is a gun that places an apparatus consisting of three polypropylene rings that, through the compression among them of the severed edges of the bowel, realize a sutureless anastomosis and are spontaneously evacuated. Fifty-eight colonic anastomoses were performed in dogs with this device; 23 stapled colonic anastomoses were also executed concurrently. Forty-four animals underwent a relaparotomy to remove the colonic specimen containing the anastomoses. Bursting pressure and the histologic features of the anastomoses were evaluated at different time intervals after operation. A good healing of all compression anastomoses was observed, thereby allowing them to initiate the experience in humans. Thirteen anastomoses (6 colorectal extraperitoneal, 1 colorectal intraperitoneal, 5 colocolonic, 1 ileorectal) were performed at the 1st Surgical Department, Milan University. One subclinical leakage (7.7%) spontaneously healed in a few days. No stenoses were observed. Images Fig. 1. Fig. 2., Fig. 4., Fig. 6. Fig. 3., Fig. 5., Fig. 7. Fig. 8. Fig. 9. PMID:3345111

Rosati, R; Rebuffat, C; Pezzuoli, G

1988-01-01

412

Experimental Results From a 2kW Brayton Power Conversion Unit  

NASA Technical Reports Server (NTRS)

This paper presents experimental test results from operation of a 2 kWe Brayton power conversion unit. The Brayton converter was developed for a solar dynamic power system flight experiment planned for the Mir Space Station in 1997. The flight experiment was cancelled, but the converter was tested at Glenn Research Center as part of the Solar Dynamic Ground Test Demonstration system which included a solar concentrator, heat receiver, and space radiator. In preparation for the current testing, the heat receiver was removed and replaced with an electrical resistance heater, simulating the thermal input of a steady-state nuclear source. The converter was operated over a full range of thermal input power levels and rotor speeds to generate an overall performance map. The converter unit will serve as the centerpiece of a Nuclear Electric Propulsion Testbed at Glenn. Future potential uses for the Testbed include high voltage electrical controller development, integrated electric thruster testing and advanced radiator demonstration testing to help guide high power Brayton technology development for Nuclear Electric Propulsion (NEP).

Hervol, David; Mason, Lee; Birchenough, Arthur

2003-01-01

413

Experimental results from a preclinical X-ray phase-contrast CT scanner  

PubMed Central

To explore the future clinical potential of improved soft-tissue visibility with grating-based X-ray phase contrast (PC), we have developed a first preclinical computed tomography (CT) scanner featuring a rotating gantry. The main challenge in the transition from previous bench-top systems to a preclinical scanner are phase artifacts that are caused by minimal changes in the grating alignment during gantry rotation. In this paper, we present the first experimental results from the system together with an adaptive phase recovery method that corrects for these phase artifacts. Using this method, we show that the scanner can recover quantitatively accurate Hounsfield units in attenuation and phase. Moreover, we present a first tomography scan of biological tissue with complementary information in attenuation and phase contrast. The present study hence demonstrates the feasibility of grating-based phase contrast with a rotating gantry for the first time and paves the way for future in vivo studies on small animal disease models (in the mid-term future) and human diagnostics applications (in the long-term future). PMID:23019354

Tapfer, Arne; Bech, Martin; Velroyen, Astrid; Meiser, Jan; Mohr, Jürgen; Walter, Marco; Schulz, Joachim; Pauwels, Bart; Bruyndonckx, Peter; Liu, Xuan; Sasov, Alexander; Pfeiffer, Franz

2012-01-01

414

MHD activity in the ISX-B tokamak: experimental results and theoretical interpretation  

SciTech Connect

The observed spectrum of MHD fluctuations in the ISX-B tokamak is clearly dominated by the n=1 mode when the q=1 surface is in the plasma. This fact agrees well with theoretical predictions based on 3-D resistive MHD calculations. They show that the (m=1; n=1) mode is then the dominant instability. It drives other n=1 modes through toroidal coupling and n>1 modes through nonlinear couplings. These theoretically predicted mode structures have been compared in detail with the experimentally measured wave forms (using arrays of soft x-ray detectors). The agreement is excellent. More detailed comparisons between theory and experiment have required careful reconstructions of the ISX-B equilibria. The equilibria so constructed have permitted a precise evaluation of the ideal MHD stability properties of ISX-B. The present results indicate that the high ..beta.. ISX-B equilibria are marginally stable to finite eta ideal MHD modes. The resistive MHD calculations also show that at finite ..beta.. there are unstable resistive pressure driven modes.

Carreras, B.A.; Dunlap, J.L.; Bell, J.D.; Charlton, L.A.; Cooper, W.A.; Dory, R.A.; Hender, T.C.; Hicks, H.R.; Holmes, J.A.; Lynch, V.E.

1982-01-01

415

Comparison between simulation models and experimental results for a planar He-Xe microdischarge  

NASA Astrophysics Data System (ADS)

A one-dimensional self-consistent simulation of a dc planar He-Xe microdischarge is used to investigate the effect of gas mixture composition and pressure on the breakdown and current-voltage characteristics, and on the vacuum ultraviolet efficiency of the discharge. The time dependent continuity equations for electrons and ions and Poisson's equation are solved successively until steady state is reached. The electric model is coupled to a model of the excited species kinetics and VUV emission. The efficiency of resonant emission of xenon atoms at 147 nm and of xenon dimers at 150 nm, defined as the ratio of the volume density of VUV emission intensity versus dissipated electrical power, is maximized at a specific pressure for mixtures with specific xenon concentration. The results of the 1D model are compared with other experimental and theoretical studies of He-Xe microdischarges. A similar 1D model of an ac plasma display panel cell is used to investigate similar pressure dependent maxima for ac PDPs.

Veronis, Georgios; Inan, Umran; Pasko, Victor

2000-10-01

416

Bioimaging and biospectra analysis by means of independent component analysis: experimental results  

NASA Astrophysics Data System (ADS)

Analysis of bioimaging and biospectra data has received increasingly attention in recent years. Here we will present two experimental results based on independent component analysis (ICA): differentiation of superparamagnetic iron oxide (SPIO) nanoparticles used as contrast agents in magnetic resonance imaging (MRI), and differentiation of mixed chemical analytes by surface-enhanced Raman scattering (SERS). The SPIO nanoparticles have been applied extensively as contrast agent in MRI for tracking of stem cells, targeted detection of cancer, due to its biocompatible and biodegradable features. For differentiation of SPIO from the background signal (e.g. interface between air and tissues), the signal voids from multiple sources makes the task very difficult. To solve this problem, we assume that the number of sensors corresponds to the number of acquisitions with different combinations of MR parameters, i.e., longitudinal and transverse relaxation times. For detection of chemical and biological analytes, the SERS approach has drawn more interest because of its high sensitivity. SERS spectra of mixed analytes were acquired at different locations of a silver nanorod array substrate. Due to the nonuniform diffusion and adsorption of the analytes, these spectra have been successfully used to identify the characteristic SERS spectrum of individual analytes. In both the MRI and SERS data, signal source separation (SPIO or mixed chemical analytes from background signal) was performed on a pixel by pixel basis. The ICA was performed by a spatial analysis using the fast ICA method.

Zhao, Qun; Langley, Jason; Lee, Joonsang; Abell, Justin; Zhao, Yiping

2011-06-01

417

Experimental Results from a 2 kW Brayton Power Conversion Unit  

NASA Astrophysics Data System (ADS)

This paper presents experimental test results from operation of a 2 kWe Brayton power conversion unit. The Brayton converter was developed for a solar dynamic power system flight experiment planned for the Mir Space Station in 1997. The flight experiment was cancelled, but the converter was tested at Glenn Research Center as part of the Solar Dynamic Ground Test Demonstration system which included a solar concentrator, heat receiver, and space radiator. In preparation for the current testing, the heat receiver was removed and replaced with an electrical resistance heater, simulating the thermal input of a steady-state nuclear source. The converter was operated over a full range of thermal input power levels and rotor speeds to generate an overall performance map. The converter unit will serve as the centerpiece of a Nuclear Electric Propulsion Testbed at Glenn. Future potential uses for the Testbed include high voltage electrical controller development, integrated electric thruster testing and advanced radiator demonstration testing to help guide high power Brayton technology development for NEP.

Hervol, David; Mason, Lee; Birchenough, Arthur

2003-01-01

418

Non-Shock Initiation Model for Plastic Bonded Explosive PBXN-5 and Cast Explosive: Experimental Results  

NASA Astrophysics Data System (ADS)

A damage initiated reaction (DMGIR) computational model is being developed for the CTH shock physics code to predict the response of an explosive to non-shock mechanical insults. The distinguishing feature of this model is the introduction of a damage variable, which relates the evolution of damage to the initiation of reaction in the explosive, and its growth to detonation. The DMGIR model is a complement to the History Variable Reactive Burn (HVRB) model embedded in the current CTH code. Specifically designed experiments are supporting the development, implementation, and validation of the DMGIR numerical approach. PBXN-5 was the initial explosive material used experimentally to develop the DMGIR model. This explosive represents a family of plastically bonded explosives with good mechanical strength and rigid body properties. The model has been extended to cast explosives represented by Composition B. Furthermore, the DMGIR model will extended to predict results of non-shock mechanical insults for moldable plastic explosives such as C4 and PrimaSheet.

Anderson, Mark; Todd, Steven; Caipen, Terry; Jensen, Charlie; Hughs, Chance

2009-06-01

419

Vibrational reduction in integral-damped composite fan blades: experimental results  

NASA Astrophysics Data System (ADS)

The experimental behavior of spinning laminated composite pretwisted plates (turbo-fan blade-like) with small (less than 10% by volume) integral viscoelastic damping patches is investigated. Two different plate sets were examined. The first set investigated tailoring patch locations and definitions to damp specific modes on spinning flat graphite/epoxy plates as a function of rotational speed. The second set investigated damping patch size and location on specific modes of pretwisted (30 degrees) graphite/epoxy plates. The results reveal that: (1) significant amount of damping can be added using a small amount of damping material, (2) the damped plates experienced no failures up to the tested 28,000 g's and 750,000 cycles, (3) centrifugal loads caused an increase in bending frequencies and corresponding reductions in bending damping levels that are proportional to the bending stiffness increase, and (4) the centrifugal loads caused a decrease in torsion natural frequency and increase in damping levels of pretwisted composite plates.

Kosmatka, John B.; Mehmed, Oral

1998-06-01

420

Regional Assesssment and Monitoring of Teh Carbon Balance Within Europe (recab): Experimental Strategy and Mesoscale Modeling Preliminary Results  

NASA Astrophysics Data System (ADS)

The aim of RECAB project (EU project EVK2-CT-1999-00034) is to quantify the contribution of fossil fuel and biospheric sources and sinks of CO2 in Europe to the atmospheric concentration at the regional scale by using a generic coupled bio- sphere atmosphere modelling and experimental approach. To achieve this, a coupled mesoscale-land surface model incorporating the biosphere is being developed; a flux aircraft for low flying purposes was set up and is being used for the regional flux mea- surements (Sky Arrow 650 TCN version ERA); and a system for collecting flask sam- ples to determine gas concentrations (CH4, CO2 and N2O) and isotope ratios (ä13C and ä18O in CO2) is operative on small aircrafts is also set up. The ERA represents the first attempt in Europe to measure surface mass and energy fluxes using airborne eddy covariance. The ERA uses the Best Aircraft Turbulence Probe (BAT) probe that is being developed by NOAA and Airborne Research Australia (ARA). The BAT in- corporates a pressure sphere housing with a synthesis of differential GPS (DGPS), solid-state sensors, and electronic and aerodynamic technology to allow high fidelity turbulence measurements from any aeroplane. CO2 and water vapour concentrations are measured using a fast response open-path infrared gas analyser (LiCor7500) which is mounted on the aircraft nose. For the flask sampling air probes are taken as twin pairs at different flight levels. During the flights the track is recorded by GPS and meteorological parameters as also the CO2 concentration (LiCor6251) are measured online to employ a CBL-Budget-Method as another approach. Additional air probes are taken with a similar sampling unit at ground level within sites of characteristic land use for gas concentration analyses and isotope ratio determination. Three summer (Valencia, Spain; Hainich, Germany; Norunda, Sweden) and three winter (Valencia; 1 Hainich; Loobos, Netherlands) experimental campaigns were successfully executed. Experimental deployments and preliminary experimental an modelling results show- ing different synoptic weather conditions are available, including CO2 vertical profiles (isotopes and concentration), horizontal flux transects and other relevant parameters. Also measurements from eddy flux towers in the measurement areas. are available, and in addition various ABL probes (RASS, SODAR, tethered balloons). 2

Dolman, H.; de Martino, B.; Gioli, B.; Hutjes, R. W. A.; Lindroth, A.; Miglietta, F.; Millan, M. M.; Sanz, M. J.; Schumacher, M.

421

The influence of quark energy loss on extracting nuclear sea quark distribution from nuclear Drell-Yan experimental data  

E-print Network

By means of two typical kinds of quark energy loss parametrization and the nuclear parton distributions determined only with lepton-nuclear deep inelastic scattering experimental data, a leading order analysis are performed on the proton-induced Drell-Yan differential cross section ratios of tungsten versus deuterium as a function of the quark momentum fraction in the beam proton and target nuclei. It is found that the theoretical results with quark energy loss are in good agreement with the experimental data. The quark energy loss effect produce approximately 3% to 11% suppression on the Drell-Yan differential cross section ratios $R_{W/D}$ in the range $0.05\\leq x_2\\leq0.3$. The application of nuclear Drell-Yan data with heavy targets is remarkably subject to difficulty in the constraints of the nuclear sea-quark distribution.

Duan Chun-Gui; Liu Na

2008-09-28

422

Experimental energy consumption of Frame Slotted ALOHA and Distributed Queuing for data collection scenarios.  

PubMed

Data collection is a key scenario for the Internet of Things because it enables gathering sensor data from distributed nodes that use low-power and long-range wireless technologies to communicate in a single-hop approach. In this kind of scenario, the network is composed of one coordinator that covers a particular area and a large number of nodes, typically hundreds or thousands, that transmit data to the coordinator upon request. Considering this scenario, in this paper we experimentally validate the energy consumption of two Medium Access Control (MAC) protocols, Frame Slotted ALOHA (FSA) and Distributed Queuing (DQ). We model both protocols as a state machine and conduct experiments to measure the average energy consumption in each state and the average number of times that a node has to be in each state in order to transmit a data packet to the coordinator. The results show that FSA is more energy efficient than DQ if the number of nodes is known a priori because the number of slots per frame can be adjusted accordingly. However, in such scenarios the number of nodes cannot be easily anticipated, leading to additional packet collisions and a higher energy consumption due to retransmissions. Contrarily, DQ does not require to know the number of nodes in advance because it is able to efficiently construct an ad hoc network schedule for each collection round. This kind of a schedule ensures that there are no packet collisions during data transmission, thus leading to an energy consumption reduction above 10% compared to FSA. PMID:25061839

Tuset-Peiro, Pere; Vazquez-Gallego, Francisco; Alonso-Zarate, Jesus; Alonso, Luis; Vilajosana, Xavier

2014-01-01

423

Experimental Energy Consumption of Frame Slotted ALOHA and Distributed Queuing for Data Collection Scenarios  

PubMed Central

Data collection is a key scenario for the Internet of Things because it enables gathering sensor data from distributed nodes that use low-power and long-range wireless technologies to communicate in a single-hop approach. In this kind of scenario, the network is composed of one coordinator that covers a particular area and a large number of nodes, typically hundreds or thousands, that transmit data to the coordinator upon request. Considering this scenario, in this paper we experimentally validate the energy consumption of two Medium Access Control (MAC) protocols, Frame Slotted ALOHA (FSA) and Distributed Queuing (DQ). We model both protocols as a state machine and conduct experiments to measure the average energy consumption in each state and the average number of times that a node has to be in each state in order to transmit a data packet to the coordinator. The results show that FSA is more energy efficient than DQ if the number of nodes is known a priori because the number of slots per frame can be adjusted accordingly. However, in such scenarios the number of nodes cannot be easily anticipated, leading to additional packet collisions and a higher energy consumption due to retransmissions. Contrarily, DQ does not require to know the number of nodes in advance because it is able to efficiently construct an ad hoc network schedule for each collection round. This kind of a schedule ensures that there are no packet collisions during data transmission, thus leading to an energy consumption reduction above 10% compared to FSA. PMID:25061839

Tuset-Peiro, Pere; Vazquez-Gallego, Francisco; Alonso-Zarate, Jesus; Alonso, Luis; Vilajosana, Xavier

2014-01-01

424

Introduction Random Walks Random Walks with Tabu Lists In Messages In Nodes Experimental Results Conclusion Routing Algorithms using Random Walks  

E-print Network

Wireless Sensor Network (WSN) a b a b c d e f PP A node has : low memory, low computation power finite Experimental Results Conclusion Routing a b c d e f P a #12;Introduction Random Walks Random Walks with Tabu Lists In Messages In Nodes Experimental Results Conclusion Routing a b c d e f P a d f e P 3 / 34 #12

Devismes, Stéphane

425

Validation of computer-generated results with experimental data obtained for torsional vibration of synchronous motor-driven turbomachinery  

E-print Network

VALIDATION OF COMPUTER-GENERATED RESULTS WITH EXPERIMENTAL DATA OBTAINED FOR TORSIONAL VIBRATION OF SYNCHRONOUS MOTOR-DRIVEN TURBOMACHINERY A Thesis by NIRMAL KIRTIKUMAR GANATRA Submitted to the Office of Graduate Studies of Texas A&M University... in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 2003 Major Subject: Mechanical Engineering VALIDATION OF COMPUTER-GENERATED RESULTS WITH EXPERIMENTAL DATA OBTAINED FOR TORSIONAL VIBRATION OF SYNCHRONOUS MOTOR...

Ganatra, Nirmal Kirtikumar

2004-09-30

426

Infrared, Raman and VCD spectra of ( S)-(+)-Carvone-comparison of experimental and ab initio theoretical results  

NASA Astrophysics Data System (ADS)

The infrared, Raman and vibrational circular dichroism spectra of the rotational isomers of ( S)-(+)-carvone have been calculated and compared to the experimental spectra. From the comparison, the conformeric composition of carvone could be deduced. It corresponded to the composition calculated from the energy differences of the two conformers with lowest energy for room temperature. A complete assignment of the vibrational bands to normal modes has been proposed.

Hoffmann, Günter Georg

2003-12-01

427

Primary experimental results of wire-array Z-pinches on PTS  

NASA Astrophysics Data System (ADS)

The Primary Test Stand (PTS) developed at the China Academy of Engineering Physics is a multiterawatt pulsed power driver, which can deliver a ˜10 MA, 70 ns rise-time (10%-90%) current to a short circuit load and has important applications in Z-pinch driven inertial confinement fusion and high energy density physics. In this paper, primary results of tungsten wire-array Z-pinch experiments on PTS are presented. The load geometries investigated include 15-mm-tall cylindrical single and nested arrays with diameter ranging from 14.4-26.4 mm, and consisting of 132˜276 tungsten wires with 5˜10 ?m in diameter. Multiple diagnostics were fielded to determine the characteristics of x-ray radiations and to obtain self-emitting images of imploding plasmas. X-ray power up to 80 TW with ˜3 ns FWMH is achieved by using nested wire arrays. The total x-ray energy exceeds 500 kJ and the peak radiation temperature is about 150 eV. Typical velocity of imploding plasmas goes around 3˜5×107 cm/s and the radial convergence ratio is between 10 and 20.

Huang, X. B.; Zhou, S. T.; Ren, X. D.; Dan, J. K.; Wang, K. L.; Zhang, S. Q.; Li, J.; Xu, Q.; Cai, H. C.; Duan, S. C.; Ouyang, K.; Chen, G. H.; Ji, C.; Wang, M.; Feng, S. P.; Yang, L. B.; Xie, W. P.; Deng, J. J.

2014-12-01

428

Experimental results on trapping a gun plasma in a toroidal magnetic cusp experiment  

NASA Astrophysics Data System (ADS)

A start-up method for producing a plasma in the bi-cusp field configuration of a toroidal magnetic cusp (TORMAC) is described. The method uses the radial injection and trapping of a toroidal gun plasma. Measurements of an injected plasma with a velocity of 17 ?sec–1 and 4·5 × 1018 particles is presented. The plasma was observed to be stopped and trapped in an equilibrium position. A well-defined outer boundary remained stationary for 20 ?sec. Particle flux distribution emanating from the cusp field lines defined a sheath having a width of 1–1·5 ion gyroradii in the poloidial field. This translates to a narrow outer boundary and a broad inner boundary based on the gradient of the poloidial field at the two radial positions. Measurements of Thomson scattering and interferometry give a Te of 15eV, a 15?sec density decay time, and a 5?sec energy decay time. These results show that this injection and trapping method is successful, and thus a higher gun plasma energy combined with a flux conserving barrier may lead to higher temperatures for testing containment in TORMAC.

Pincosy, P. A.; Myers, B. R.; Levine, M. A.; Feinberg, B.; Niland, R. A.; Soroka, L.

1984-12-01

429

Preliminary Experimental Results of Integrated Gasification Fuel Cell Operation Using Hardware Simulation  

SciTech Connect

A newly developed integrated gasification fuel cell (IGFC) hybrid system concept has been tested using the Hybrid Performance (Hyper) project hardware-based simulation facility at the U.S. Department of Energy, National Energy Technology Laboratory. The cathode-loop hardware facility, previously connected to the real-time fuel cell model, was integrated with a real-time model of a gasifier of solid (biomass and fossil) fuel. The fuel cells are operated at the compressor delivery pressure, and they are fueled by an updraft atmospheric gasifier, through the syngas conditioning train for tar removal and syngas compression. The system was brought to steady state; then several perturbations in open loop (variable speed) and closed loop (constant speed) were performed in order to characterize the IGFC behavior. Coupled experiments and computations have shown the feasibility of relatively fast control of the plant as well as a possible mitigation strategy to reduce the thermal stress on the fuel cells as a consequence of load variation and change in gasifier operating conditions. Results also provided an insight into the different features of variable versus constant speed operation of the gas turbine section.

Traverso, Alberto; Tucker, David; Haynes, Comas L.

2012-07-01

430

RESEARCH RESULTS FORUM FOR RENEWABLE ENERGY TECHNOLOGY AND RESOURCE ASSESSMENTS  

E-print Network

RESEARCH RESULTS FORUM FOR RENEWABLE ENERGY TECHNOLOGY AND RESOURCE ASSESSMENTS Public Workshop Research Recommendations by Technology 1. DOE SunShot set the goal of $0.06 per kWh for 2020 2. CSP-Tower and enhanced thermal storage 3. Development and production of both Silicon-based and nanostructured solar cells

California at Davis, University of

431

Changes in quantitative SPECT thallium-201 results associated with the use of energy-weighted acquisition  

SciTech Connect

The effect of utilizing energy-weighted acquisition on quantitative analysis of SPECT thallium-201 images was evaluated by simultaneously acquiring energy-weighted and windowed projection images in ten patients. The paired image sets were processed identically and evaluated by probability analysis of defect magnitude as indicated by a commercially available software analysis package. It was predicted that defect magnitude would increase as a result of improved image contrast. This was confirmed experimentally. One should be cautious in relying on strict quantitative criteria in cardiac studies with thallium-201, especially when major changes in the imaging system or technique are introduced.

Floyd, J.L.; Mann, R.B.; Shaw, A. (Mercy Medical Center, Cedar Rapids, IA (USA))

1991-05-01

432

A comparison of experimental and theoretical results for rotordynamic coefficients of four annular gas seals  

NASA Technical Reports Server (NTRS)

The test facility and initial test program developed to experimentally measure the fluid forces induced by annular gas seals is described. A comparison of theoretically predicted and experimentally obtained data for smooth and honeycomb seals is provided. And a comparison of experimental data from the tests of three smooth-rotor/smooth-stator seals is provided. The leakage of the working fluid through the seal, the pressure gradient along the seal length, entrance pressure-loss data, and rotordynamic coefficients provide a basis for comparison. A short discussion on seal theory is included, and various rotordynamic coefficient identification schemes are described.

Childs, D. W.; Nelson, C. C.; Elrod, D.; Nicks, C.

1985-01-01

433

Storage-and-release flux rope eruptions in the laboratory: initial results and experimental plans  

NASA Astrophysics Data System (ADS)

Solar eruptive events such as coronal mass ejections (CMEs) are thought to be driven by a sudden release of magnetic energy stored in the corona. In many cases, the pre-eruptive configuration is a non-potential magnetic structure that can be modeled as a line-tied magnetic flux rope. In spite of ever-improving observational capabilities, directly studying the evolution of coronal flux ropes remains a significant challenge. Thus, in order to further explore the mechanisms that drive solar eruptions, we must find novel ways to simulate the relevant physical system. To this end, we have constructed a new laboratory experiment to study storage-and-release flux rope eruptions. This experiment contains a carefully designed set of ``sub-photospheric" coils that produces an active-region-like potential field configuration that remains static throughout the discharge. An arched magnetic flux rope plasma is formed within this potential field configuration by driving electric current through two line-tied footpoints (copper electrodes). Over the course of the discharge, the plasma current is quasi-statically increased (to tens of kiloamperes over many Alfvén times) in order to slowly build up magnetic energy in the system. As the flux rope gains energy, it will expand away from the electrodes to a point where it is expected to undergo a dynamic eruption due to the onset of a loss-of-equilibrium [Forbes & Isenberg, Astrophys. J. 373, 294 (1991)] or the torus instability [Kliem & Török, Phys. Rev. Lett. 96, 255002 (2006)]. In these experiments, the structure of the background potential field configuration (i.e., the field decay index) can be varied to study its effect on the observed flux rope eruptions. Initial results from these experiment are presented, including images from a fast visible light camera and direct measurements from internal magnetic diagnostics. This research is supported by DoE Contract Number DE-AC02-09CH11466 and by the Center for Magnetic Self-Organization (CMSO).; Specially designed magnetic field coils (orange and blue) are used to produce an active-region-like potential field configuration within the vacuum vessel (gray). An arched magnetic flux rope plasma is formed by driving electric current along low-lying potential field lines (blue/green). As magnetic energy builds up in the flux rope, it will expand outward and possibly undergo a storage-and-release eruption.

Myers, C. E.; Yamada, M.; Ji, H.; Yoo, J.; Jara-Almonte, J.; Lawrence, E. E.

2012-12-01

434

Experimental investigations in particle physics at intermediate energies  

SciTech Connect

The major elements of this project continues to be on fundamental symmetries and parameters of the Standard Model. The projects in the current period have been BNL E791 (a search for the decay K{sub L}{sup 0} {yields} {mu}e, which would violate the rule of separate lepton number conservation), test of an upgrade proposal (E871), and LSND, a neutrino experiment at LAMPF. For E791, data taking was completed in June 1990, and preliminary results are now available for the decays K{sub L}{sup 0} {yields} {mu}e and K{sub L}{sup 0} {yields} {mu}{mu}from the entire data set. The data for decay K{sub L}{sup 0} {yields} ee are still being analysed. These are an upper limit for the branching fraction for K{sub L}{sup 0} {yields} {mu}e of 3.5 {times} 10{sup {minus}11} (90% C.L.). From the 1990 data alone, we have a new (preliminary) value of the branching fraction for K{sub L}{sup 0} {yields} {mu}{mu} of (6.96{plus minus}0. 4{plus minus}0.22) {times} 10{sup {minus}9}, with a sample of 349 events. Combining this with earlier data gives (6.96{plus minus}0.34) {times} 10{sup 9}, by far the most precise value. The limit on the decay K{sub L}{sup 0} {yields} {mu}e places a lower limit on the mass of a new particle mediating such decays of 85 TeV. The LSND (Large Scintillator Neutrino Detector), a search for neutrino oscillations at LAMPF, has been approved, and is now underway. Other neutrino work at Los Alamos, E764, has resulted in a final publication. This includes the best, measurement of {nu}-nuclear scattering, in {nu}{sub mu} {sup 12}C inclusive cross sections. The measurement of the cross section for the exclusive reaction {nu}{sup mu}{sup 12}C {yields} {mu}{sup {minus}12} N is unique. In a new development, Dr. Martoff has established a facility for fabrication of superconducting detectors of nuclear radiation; the equipment has been funded and is partly installed. Planned uses include scattering for Dark Matter.' In summary, the objectives for this year have been met.

Auerbach, L.B.; Highland, V.L.; Martoff, C.J.; McFarlane, K.W.; Guss, C.; Kettell, S.

1991-09-30

435

The Pierre Auger Observatory: results on the highest energy particles  

E-print Network

The Pierre Auger Observatory has been designed to investigate the most energetic particles known, the ultra high energy cosmic rays. The observatory, covering an area of 3000 km^2, combines two different detection techniques to study the huge particle showers created by the interaction of primary cosmic rays with the atmosphere. The analysis of the showers allows one to extract information on the nature of the primary cosmic rays, as well as their origin. Moreover, the study of the interaction of these particles with the atmosphere offers a unique window to study particle physics at an energy more than one order of magnitude above the current highest energy human-made accelerator. In this contribution selected results are presented, with a focus on the primary mass composition, the determination of the number of muons, which is sensitive to the shower hadronic interactions, and the measurement of the proton-air cross-section at sqrt(s) = 57 TeV. For the last topic, a link with the proton-proton cross-section measurements using accelerators will be made. Results on the cosmic ray energy spectrum and on searches for ultra high energy photons and neutrinos, will also be discussed.

Ruben Conceição; for the Pierre Auger Collaboration

2013-07-15

436

Cabauw Experimental Results from the Project for Intercomparison of Land-Surface Parameterization Schemes  

NASA Technical Reports Server (NTRS)

In the Project for Intercomparison of Land-Surface Parameterization Schemes phase 2a experiment, meteorological data for the year 1987 from Cabauw, the Netherlands, were used as inputs to 23 land-surface flux schemes designed for use in climate and weather models. Schemes were evaluated by comparing their outputs with long-term measurements of surface sensible heat fluxes into the atmosphere and the ground, and of upward longwave radiation and total net radiative fluxes, and also comparing them with latent heat fluxes derived from a surface energy balance. Tuning of schemes by use of the observed flux data was not permitted. On an annual basis, the predicted surface radiative temperature exhibits a range of 2 K across schemes, consistent with the range of about 10 W/m in predicted surface net radiation. Most modeled values of monthly net radiation differ from the observations by less than the estimated maximum monthly observational error (+/- 10 W/sq m). However, modeled radiative surface temperature appears to have a systematic positive bias in most schemes; this might be explained by an error in assumed emissivity and by models' neglect of canopy thermal heterogeneity. Annual means of sensible and latent heat fluxes, into which net radiation is partitioned, have ranges across schemes of 30 W/sq m and 25 W/sq m, respectively. Annual totals of evapotranspiration and runoff, into which the precipitation is partitioned, both have ranges of 315 mm. These ranges in annual heat and water fluxes were approximately halved upon exclusion of the three schemes that have no stomatal resistance under non-water-stressed conditions. Many schemes tend to underestimate latent heat flux and overestimate sensible heat flux in summer, with a reverse tendency in winter. For six schemes, root-mean-square deviations of predictions from monthly observations are less than the estimated upper bounds on observation errors (5 W/m for sensible beat flux and 10 W/m for latent heat flux). Actual runoff at the site is believed to be dominated by vertical drainage to ground water, but several schemes produced significant amounts of runoff as overland flow or interflow. There is a range across schemes of 184 mm (40% of total pore volume) in the simulated annual mean root-zone soil moisture. Unfortunately, no measurements of soil moisture were available for model evaluation. A theoretical analysis suggested that differences in boundary conditions used in various schemes are not sufficient to explain the large variance in soil moisture. However, many of the extreme values of soil moisture could be explained in terms of the particulars of experimental setup or excessive evapotranspiration.

Chen, Tian Hong; Henderson-Sellers, A.; Milly, P. C. D.; Pitman, A. J.; Beljaars, A. C. M.; Polcher, J.; Abramopoulos, F.; Boone, A.; Chang, S.; Chen, F.; Dai, Y.; Desborough, C. E.; Dickinson, R. E.; Duemenil, L.; Ek, M.; Garratt, J. R.; Gedney, N.; Gusev, Y. M.; Kim, J.; Koster, R.

1997-01-01

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