Experimental Test Results of Energy Efficient Transport (EET) High-Lift Airfoil in Langley Low-Turbulence Pressure Tunnel

NASA Technical Reports Server (NTRS)

Morgan, Harry L., Jr.

2002-01-01

This report describes the results of an experimental study conducted in the Langley Low-Turbulence Pressure Tunnel to determine the effects of Reynolds number and Mach number on the two-dimensional aerodynamic performance of the Langley Energy Efficient Transport (EET) High-Lift Airfoil. The high-lift airfoil was a supercritical-type airfoil with a thickness-to- chord ratio of 0.12 and was equipped with a leading-edge slat and a double-slotted trailing-edge flap. The leading-edge slat could be deflected -30 deg, -40 deg, -50 deg, and -60 deg, and the trailing-edge flaps could be deflected to 15 deg, 30 deg, 45 deg, and 60 deg. The gaps and overlaps for the slat and flaps were fixed at each deflection resulting in 16 different configurations. All 16 configurations were tested through a Reynolds number range of 2.5 to 18 million at a Mach number of 0.20. Selected configurations were also tested through a Mach number range of 0.10 to 0.35. The plotted and tabulated force, moment, and pressure data are available on the CD-ROM supplement L-18221.

Advanced Supersonic Nozzle Concepts: Experimental Flow Visualization Results Paired With LES

NASA Astrophysics Data System (ADS)

Berry, Matthew; Magstadt, Andrew; Stack, Cory; Gaitonde, Datta; Glauser, Mark; Syracuse University Team; The Ohio State University Team

2015-11-01

Advanced supersonic nozzle concepts are currently under investigation, utilizing multiple bypass streams and airframe integration to bolster performance and efficiency. This work focuses on the parametric study of a supersonic, multi-stream jet with aft deck. The single plane of symmetry, rectangular nozzle, displays very complex and unique flow characteristics. Flow visualization techniques in the form of PIV and schlieren capture flow features at various deck lengths and Mach numbers. LES is compared to the experimental results to both validate the computational model and identify limitations of the simulation. By comparing experimental results to LES, this study will help create a foundation of knowledge for advanced nozzle designs in future aircraft. SBIR Phase II with Spectral Energies, LLC under direction of Barry Kiel.

Experimental investigation of fan-folded piezoelectric energy harvesters for powering pacemakers.

PubMed

Ansari, M H; Karami, M Amin

2017-06-01

This paper studies the fabrication and testing of a magnet free piezoelectric energy harvester (EH) for powering biomedical devices and sensors inside the body. The design for the EH is a fan-folded structure consisting of bimorph piezoelectric beams folding on top of each other. An actual size experimental prototype is fabricated to verify the developed analytical models. The model is verified by matching the analytical results of the tip acceleration frequency response functions (FRF) and voltage FRF with the experimental results. The generated electricity is measured when the EH is excited by the heartbeat. A closed loop shaker system is utilized to reproduce the heartbeat vibrations. Achieving low fundamental natural frequency is a key factor to generate sufficient energy for pacemakers using heartbeat vibrations. It is shown that the natural frequency of the small-scale device is less than 20 Hz due to its unique fan-folded design. The experimental results show that the small-scale EH generates sufficient power for state of the art pacemakers. The 1 cm 3 EH with18.4 gr tip mass generates more than16 μ W of power from a normal heartbeat waveform. The robustness of the device to the heart rate is also studied by measuring the relation between the power output and the heart rate.

Experimental Potential Energy Curve for the 43 Π Electronic State of NaCs

NASA Astrophysics Data System (ADS)

Steely, Andrew; Cooper, Hannah; Zain, Hareem; Whipp, Ciara; Faust, Carl; Kortyna, Andrew; Huennekens, John

2017-04-01

We present results from experimental studies of the 43 Π electronic state of the NaCs molecule. This electronic state is interesting in that its potential energy curve likely exhibits a double minimum. As a result, interference effects are observed in the resolved bound-free fluorescence spectra. The optical-optical double resonance method was used to obtain Doppler-free excitation spectra for the 43 Π state. This dataset of measured level energies was expanded largely by observing fluorescence from levels populated by collisions. To aid in level assignments, simulations of resolved bound-free fluorescence spectra were calculated using the BCONT program (R. J. Le Roy, University of Waterloo). Spectroscopic constants were determined to summarize data belonging to inner well, outer well, and above barrier regions of the electronic state. Current work focuses on using the IPA method to construct an experimental potential energy curve. Work supported by NSF and Susquehanna University.

Experimental and theoretical research in high energy astrophysics

NASA Technical Reports Server (NTRS)

Clark, George W.

1990-01-01

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.

Experimental and theoretical studies on solar energy for energy conversion

NASA Technical Reports Server (NTRS)

Thomas, A. P.; Thekaekara, M. P.

1976-01-01

This paper presents the results of investigations made experimentally and theoretically to evaluate the various parameters that affect the amount of solar energy received on a collector surface. Measurements were made over a long period of time using both pyranometer and pyrheliometer. Computation of spectral and total irradiance at ground level have been made for a large variety of combinations of atmospheric parameters for ozone density, precipitable water vapor, turbidity-coefficients and air mass. A study of the air mass as a function of irradiance measured at GSFC, and comparison of the data with the computed values of total direct solar irradiance for various parameters indicate that turbidity changes with time of the day; atmospheric opacity is less in the afternoon than in the morning.

Experimental demonstration of photon upconversion via cooperative energy pooling

DOE PAGES

Weingarten, Daniel H.; LaCount, Michael D.; van de Lagemaat, Jao; ...

2017-03-15

Photon upconversion is a fundamental interaction of light and matter that has applications in fields ranging from bioimaging to microfabrication. However, all photon upconversion methods demonstrated thus far involve challenging aspects, including requirements of high excitation intensities, degradation in ambient air, requirements of exotic materials or phases, or involvement of inherent energy loss processes. Here we experimentally demonstrate a mechanism of photon upconversion in a thin film, binary mixture of organic chromophores that provides a pathway to overcoming the aforementioned disadvantages. This singlet-based process, called Cooperative Energy Pooling (CEP), utilizes a sensitizer-acceptor design in which multiple photoexcited sensitizers resonantly andmore » simultaneously transfer their energies to a higher-energy state on a single acceptor. Data from this proof-of-concept implementation is fit by a proposed model of the CEP process. As a result, design guidelines are presented to facilitate further research and development of more optimized CEP systems.« less

Energy balance model applied to pasture experimental areas in São Paulo State, Brazil

NASA Astrophysics Data System (ADS)

Bayma-Silva, Gustavo; de Castro Teixeira, Antonio Heriberto; de Castro Victoria, Daniel; Furlan Nogueira, Sandra; Freitas Leivas, Janice; Coaguila, Daniel N.; Rodrigues Herling, Valdo

2016-10-01

The Simple Algorithm for Evapotranspiration Retrieving (SAFER) was used to estimate biophysical parameters and the energy balance components in two different pasture experimental areas, in the São Paulo state, Brazil. The experimental pastures consist in six rotational (RGS) and three continuous grazing systems (CGS) paddocks. Landsat-8 images from 2013 and 2015 dry and rainy seasons were used, as these presented similar hydrological cycle, with 1,600 mm and 1,613 mm of annual precipitation, resulting in 19 cloud-free images. Bands 1 to 7 and thermal bands 10 and 11 were used with weather data from a station located near the experimental area. NDVI, biomass, evapotranspiration and latent heat flux (λE) temporal values statistically differ CGS from RGS areas. Grazing systems influences the energy partition and these results indicate that RGS benefits biomass production, evapotranspiration and the microclimate, due higher LE values. SAFER is a feasible tool to estimate biophysical parameters and energy balance components in pasture and has potential to discriminate continuous and rotation grazing systems in a temporal analysis.

Experimental investigation of fan-folded piezoelectric energy harvesters for powering pacemakers

PubMed Central

Ansari, M H; Karami, M Amin

2018-01-01

This paper studies the fabrication and testing of a magnet free piezoelectric energy harvester (EH) for powering biomedical devices and sensors inside the body. The design for the EH is a fan-folded structure consisting of bimorph piezoelectric beams folding on top of each other. An actual size experimental prototype is fabricated to verify the developed analytical models. The model is verified by matching the analytical results of the tip acceleration frequency response functions (FRF) and voltage FRF with the experimental results. The generated electricity is measured when the EH is excited by the heartbeat. A closed loop shaker system is utilized to reproduce the heartbeat vibrations. Achieving low fundamental natural frequency is a key factor to generate sufficient energy for pacemakers using heartbeat vibrations. It is shown that the natural frequency of the small-scale device is less than 20 Hz due to its unique fan-folded design. The experimental results show that the small-scale EH generates sufficient power for state of the art pacemakers. The 1 cm3 EH with18.4 gr tip mass generates more than16 μW of power from a normal heartbeat waveform. The robustness of the device to the heart rate is also studied by measuring the relation between the power output and the heart rate. PMID:29674807

Experimental conformational energy maps of proteins and peptides.

PubMed

Balaji, Govardhan A; Nagendra, H G; Balaji, Vitukudi N; Rao, Shashidhar N

2017-06-01

We have presented an extensive analysis of the peptide backbone dihedral angles in the PDB structures and computed experimental Ramachandran plots for their distributions seen under a various constraints on X-ray resolution, representativeness at different sequence identity percentages, and hydrogen bonding distances. These experimental distributions have been converted into isoenergy contour plots using the approach employed previously by F. M. Pohl. This has led to the identification of energetically favored minima in the Ramachandran (ϕ, ψ) plots in which global minima are predominantly observed either in the right-handed α-helical or the polyproline II regions. Further, we have identified low energy pathways for transitions between various minima in the (ϕ,ψ) plots. We have compared and presented the experimental plots with published theoretical plots obtained from both molecular mechanics and quantum mechanical approaches. In addition, we have developed and employed a root mean square deviation (RMSD) metric for isoenergy contours in various ranges, as a measure (in kcal.mol -1 ) to compare any two plots and determine the extent of correlation and similarity between their isoenergy contours. In general, we observe a greater degree of compatibility with experimental plots for energy maps obtained from molecular mechanics methods compared to most quantum mechanical methods. The experimental energy plots we have investigated could be helpful in refining protein structures obtained from X-ray, NMR, and electron microscopy and in refining force field parameters to enable simulations of peptide and protein structures that have higher degree of consistency with experiments. Proteins 2017; 85:979-1001. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Inertial confinement fusion for energy: overview of the ongoing experimental, theoretical and numerical studies

NASA Astrophysics Data System (ADS)

Jacquemot, S.

2017-10-01

This paper provides an overview of the results presented at the 26th IAEA Fusion Energy Conference in the field of inertial confinement fusion for energy, covering its various experimental, numerical/theoretical and technological facets, as well as the different paths towards ignition that are currently followed worldwide.

Experimental measurement of energy harvesting with backpack

NASA Astrophysics Data System (ADS)

Pavelkova, Radka; Vala, David; Suranek, Pavel; Mahdal, Miroslav

2017-08-01

This article deals with the energy harvesting systems, especially the energy harvesting backpack, which appears as a convenient means for energy harvesting for mobile sensors power. Before starting the experiment, it was necessary to verify whether this energy will be sufficient to get acquainted with the human kinematics and analyze problematics itself. For this purpose there was used motion capture technology from Xsens. Measured data on the position of a particle moving man and back when walking, these data were then used for experimental realization of energy harvesting backpack and as input data to the simulation in Simulink, which brought us a comparison between theoretical assumptions and practical implementation. When measuring characteristics of energy harvesting system we have a problem with measurements on backpack solved when redoing of the hydraulic cylinder as a source of a suitable movement corresponding to the amplitude and frequency of human walk.

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

NASA Astrophysics Data System (ADS)

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

2014-07-01

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.

Predicting repeat protein folding kinetics from an experimentally determined folding energy landscape

PubMed Central

Street, Timothy O; Barrick, Doug

2009-01-01

The Notch ankyrin domain is a repeat protein whose folding has been characterized through equilibrium and kinetic measurements. In previous work, equilibrium folding free energies of truncated constructs were used to generate an experimentally determined folding energy landscape (Mello and Barrick, Proc Natl Acad Sci USA 2004;101:14102–14107). Here, this folding energy landscape is used to parameterize a kinetic model in which local transition probabilities between partly folded states are based on energy values from the landscape. The landscape-based model correctly predicts highly diverse experimentally determined folding kinetics of the Notch ankyrin domain and sequence variants. These predictions include monophasic folding and biphasic unfolding, curvature in the unfolding limb of the chevron plot, population of a transient unfolding intermediate, relative folding rates of 19 variants spanning three orders of magnitude, and a change in the folding pathway that results from C-terminal stabilization. These findings indicate that the folding pathway(s) of the Notch ankyrin domain are thermodynamically selected: the primary determinants of kinetic behavior can be simply deduced from the local stability of individual repeats. PMID:19177351

Closed Loop Two-Phase Thermosyphon of Small Dimensions: a Review of the Experimental Results

NASA Astrophysics Data System (ADS)

Franco, Alessandro; Filippeschi, Sauro

2012-06-01

A bibliographical review on the heat and mass transfer in gravity assisted Closed Loop Two Phase Thermosyphons (CLTPT) with channels having a hydraulic diameter of the order of some millimetres and input power below 1 kW is proposed. The available experimental works in the literature are critically analysed in order to highlight the main results and the correlation between mass flow rate and heat input in natural circulation loops. A comparison of different experimental apparatuses and results is made. It is observed that the results are very different among them and in many cases the experimental data disagree with the conventional theory developed for an imposed flow rate. The paper analyses the main differences among the experimental devices and try to understand these disagreements. From the present analysis it is evident that further systematic studies are required to generate a meaningful body of knowledge of the heat and mass transport mechanism in these devices for practical applications in cooling devices or energy systems.

Magnetic Guarding: Experimental and Numerical Results

NASA Astrophysics Data System (ADS)

Heinrich, Jonathon; Font, Gabriel; Garrett, Michael; Rose, D.; Genoni, T.; Welch, D.; McGuire, Thomas

2017-10-01

The magnetic field topology of Lockheed Martin's Compact Fusion Reactor (CFR) concept requires internal magnetic field coils. Internal coils for similar devices have leveraged levitating coils or coils with magnetically guarded supports. Magnetic guarding of supports has been investigated for multipole devices (theoretically and experimentally) without conclusive results. One outstanding question regarding magnetic guarding of supports is the magnitude and behavior of secondary plasma drifts resulting from magnetic guard fields (grad-B drifts, etc). We present magnetic-implicit PIC modeling results and preliminary proof of concept experimental results on magnetic guarding of internal-supports and the subsequent reduction in total plasma losses.

Experimental measurement of the 12C+16O fusion cross sections at astrophysical energies

NASA Astrophysics Data System (ADS)

Fang, X.; Tan, W. P.; Beard, M.; deBoer, R. J.; Gilardy, G.; Jung, H.; Liu, Q.; Lyons, S.; Robertson, D.; Setoodehnia, K.; Seymour, C.; Stech, E.; Vande Kolk, B.; Wiescher, M.; de Souza, R.; Hudan, S.; Singh, V.; Tang, X. D.; Uberseder, E.

2018-05-01

The total cross sections of the 12C+16O fusion have been experimentally determined at low energies to investigate the role of this reaction during late stellar evolution burning phases. A high-intensity oxygen beam was produced by the 5MV pelletron accelerator at the University of Notre Dame impinging on a thick ultra-pure graphite target. Protons and γ-rays were measured simultaneously in the center-of-mass energy range from 3.64 to 5.01 MeV, using strip silicon and HPGe detectors. Statistical model calculations were employed to interpret the experimental results. A new broad resonance-like structure is observed for the 12C+16O reaction, and a decreasing trend of its S-factor towards low energies is found.

A ferrofluid based energy harvester: Computational modeling, analysis, and experimental validation

NASA Astrophysics Data System (ADS)

Liu, Qi; Alazemi, Saad F.; Daqaq, Mohammed F.; Li, Gang

2018-03-01

A computational model is described and implemented in this work to analyze the performance of a ferrofluid based electromagnetic energy harvester. The energy harvester converts ambient vibratory energy into an electromotive force through a sloshing motion of a ferrofluid. The computational model solves the coupled Maxwell's equations and Navier-Stokes equations for the dynamic behavior of the magnetic field and fluid motion. The model is validated against experimental results for eight different configurations of the system. The validated model is then employed to study the underlying mechanisms that determine the electromotive force of the energy harvester. Furthermore, computational analysis is performed to test the effect of several modeling aspects, such as three-dimensional effect, surface tension, and type of the ferrofluid-magnetic field coupling on the accuracy of the model prediction.

Beam dynamics studies at DAΦNE: from ideas to experimental results

NASA Astrophysics Data System (ADS)

Zobov, M.; DAΦNE Team

2017-12-01

DAΦNE is the electron-positron collider operating at the energy of Φ-resonance, 1 GeV in the center of mass. The presently achieved luminosity is by about two orders of magnitude higher than that obtained at other colliders ever operated at this energy. Careful beam dynamic studies such as the vacuum chamber design with low beam coupling impedance, suppression of different kinds of beam instabilities, investigation of beam-beam interaction, optimization of the beam nonlinear motion have been the key ingredients that have helped to reach this impressive result. Many novel ideas in accelerator physics have been proposed and/or tested experimentally at DAΦNE for the first time. In this paper we discuss the advanced accelerator physics studies performed at DAΦNE.

Numerical and experimental design of coaxial shallow geothermal energy systems

NASA Astrophysics Data System (ADS)

Raghavan, Niranjan

Geothermal Energy has emerged as one of the front runners in the energy race because of its performance efficiency, abundance and production competitiveness. Today, geothermal energy is used in many regions of the world as a sustainable solution for decreasing dependence on fossil fuels and reducing health hazards. However, projects related to geothermal energy have not received their deserved recognition due to lack of computational tools associated with them and economic misconceptions related to their installation and functioning. This research focuses on numerical and experimental system design analysis of vertical shallow geothermal energy systems. The driving force is the temperature difference between a finite depth beneath the earth and its surface stimulates continuous exchange of thermal energy from sub-surface to the surface (a geothermal gradient is set up). This heat gradient is captured by the circulating refrigerant and thus, tapping the geothermal energy from shallow depths. Traditionally, U-bend systems, which consist of two one-inch pipes with a U-bend connector at the bottom, have been widely used in geothermal applications. Alternative systems include coaxial pipes (pipe-in-pipe) that are the main focus of this research. It has been studied that coaxial pipes have significantly higher thermal performance characteristics than U-bend pipes, with comparative production and installation costs. This makes them a viable design upgrade to the traditional piping systems. Analytical and numerical heat transfer analysis of the coaxial system is carried out with the help of ABAQUS software. It is tested by varying independent parameters such as materials, soil conditions and effect of thermal contact conductance on heat transfer characteristics. With the above information, this research aims at formulating a preliminary theoretical design setup for an experimental study to quantify and compare the heat transfer characteristics of U-bend and coaxial

Designing free energy surfaces that match experimental data with metadynamics.

PubMed

White, Andrew D; Dama, James F; Voth, Gregory A

2015-06-09

Creating models that are consistent with experimental data is essential in molecular modeling. This is often done by iteratively tuning the molecular force field of a simulation to match experimental data. An alternative method is to bias a simulation, leading to a hybrid model composed of the original force field and biasing terms. We previously introduced such a method called experiment directed simulation (EDS). EDS minimally biases simulations to match average values. In this work, we introduce a new method called experiment directed metadynamics (EDM) that creates minimal biases for matching entire free energy surfaces such as radial distribution functions and phi/psi angle free energies. It is also possible with EDM to create a tunable mixture of the experimental data and free energy of the unbiased ensemble with explicit ratios. EDM can be proven to be convergent, and we also present proof, via a maximum entropy argument, that the final bias is minimal and unique. Examples of its use are given in the construction of ensembles that follow a desired free energy. The example systems studied include a Lennard-Jones fluid made to match a radial distribution function, an atomistic model augmented with bioinformatics data, and a three-component electrolyte solution where ab initio simulation data is used to improve a classical empirical model.

The Bigfoot Drive; Experimental Results

NASA Astrophysics Data System (ADS)

Baker, Kevin; Thomas, Cliff; Khan, Shahab; Casey, Daniel; Spears, Brian; Nora, Ryan; Munro, Davis; Eder, David; Milovich, Jose; Berger, Dick; Strozzi, David; Goyon, Clement; Turnbull, David; Ma, Tammy; Izumi, Nobuhiko; Benedetti, Robin; Millot, Marius; Celliers, Peter; Yeamans, Charles; Hatarik, Robert; Landen, Nino; Hurricane, Omar; Callahan, Debbie

2016-10-01

The Bigfoot platform was developed on the National Ignition Facility to investigate low convergence, high adiabat, high rhoR hotspot implosions. This platform was designed to be less susceptible to wall motion, LPI and CBET and to be more robust against capsule hydrodynamic instabilities. To date experimental studies have been carried out at two hohlraum scales, a 5.75 and 5.4 mm diameter hohlraum. We will present experimental results from these tuning campaigns including the shape vs. cone fraction, surrogacy comparisons of self-emission from the capsules vs. radiography of the imploding capsule and doped vs. undoped capsules. Prepared by LLNL under Contract DE-AC52-07NA27344.

Acoustic analysis in Mudejar-Gothic churches: Experimental results

NASA Astrophysics Data System (ADS)

Galindo, Miguel; Zamarreño, Teófilo; Girón, Sara

2005-05-01

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. .

Acoustic analysis in Mudejar-Gothic churches: experimental results.

PubMed

Galindo, Miguel; Zamarreño, Teófilo; Girón, Sara

2005-05-01

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.

Experimental measurement of 12C+16O fusion at stellar energies

NASA Astrophysics Data System (ADS)

Fang, X.; Tan, W. P.; Beard, M.; deBoer, R. J.; Gilardy, G.; Jung, H.; Liu, Q.; Lyons, S.; Robertson, D.; Setoodehnia, K.; Seymour, C.; Stech, E.; Vande Kolk, B.; Wiescher, M.; deSouza, R. T.; Hudan, S.; Singh, V.; Tang, X. D.; Uberseder, E.

2017-10-01

The total cross section of the 12C+16O fusion reaction has been measured at low energies to investigate the role of this reaction during late stellar evolution burning phases. A high-intensity oxygen beam, produced by the 5 MV pelletron accelerator at the University of Notre Dame, impinged on a thick, ultrapure graphite target. Protons and γ rays were simultaneously measured in the center-of-mass energy range from 3.64 to 5.01 MeV for singles and from 3.73 to 4.84 MeV for coincidence events, using silicon and Ge detectors. Statistical model calculations were employed to interpret the experimental results. The emergence of a new resonance-like broad structure and a decreasing trend in the S -factor data towards lower energies (opposite to previous data) are found for the 12C+16O fusion reaction. Based on these results the uncertainty range of the reaction rate within the temperature range of late stellar burning environments is discussed.

Analysis and test results for a molten salt thermal energy storage system

NASA Astrophysics Data System (ADS)

Sterrett, R. H.; Scott, O. L.

A system has been developed to provide low cost thermal energy storage using molten salt. It consists of a hot tank to store the 565 C (1050 F) salt and a cold tank to store the 289 C (550 F) salt. The hot tank uses internal insulation protected by a liner to enable the use of a carbon steel shell for structural support. Due to the lower salt temperature, the cold tank can be a carbon steel shell with external insulation. This paper describes an analytical method used to predict the thermal performance of such systems and presents experimental data from a Subsystem Research Experiment (SRE) conducted by Martin Marietta Aerospace, Solar Energy Systems under contract from Sandia National Laboratories, Livermore, CA. The results from three of the SRE test cases are compared with the STS model results. These are (1) steady state operation, (2) concurrent charging and discharging, and (3) transient cooldown. The temperature differences between the analytical and experimental results were less than 10%. The internally insulated hot tank performed well.

Experimental Results from a Resonant Dielectric Laser Accelerator

NASA Astrophysics Data System (ADS)

Yoder, Rodney; McNeur, Joshua; Sozer, Esin; Travish, Gil; Hazra, Kiran Shankar; Matthews, Brian; England, Joel; Peralta, Edgar; Wu, Ziran

2015-04-01

Laser-powered accelerators have the potential to operate with very large accelerating gradients (~ GV/m) and represent a path toward extremely compact colliders and accelerator technology. Optical-scale laser-powered devices based on field-shaping structures (known as dielectric laser accelerators, or DLAs) have been described and demonstrated recently. Here we report on the first experimental results from the Micro-Accelerator Platform (MAP), a DLA based on a slab-symmetric resonant optical-scale structure. As a resonant (rather than near-field) device, the MAP is distinct from other DLAs. Its cavity resonance enhances its accelerating field relative to the incoming laser fields, which are coupled efficiently through a diffractive optic on the upper face of the device. The MAP demonstrated modest accelerating gradients in recent experiments, in which it was powered by a Ti:Sapphire laser well below its breakdown limit. More detailed results and some implications for future developments will be discussed. Supported in part by the U.S. Defense Threat Reduction Agency (UCLA); U.S. Dept of Energy (SLAC); and DARPA (SLAC).

New results on low energy exclusive hadronic final states from BABAR

NASA Astrophysics Data System (ADS)

Gary, J. William

2018-01-01

The 3.6 standard deviation discrepancy between the standard model (SM) prediction for the muon anomalous magnetic moment gμ - 2 and the corresponding experimental measurement is one of the most persistent and intriguing potential signals in particle physics for physics beyond the SM. The largest uncertainty in the SM prediction for gμ - 2 arises from the uncertainty in the measured low energy inclusive e+e- → hadrons cross section. New results from the BABAR experiment at SLAC for the e+e- → π+ π- π0 π0 and e+e- → KK ππ cross sections are presented that significantly reduce this uncertainty. New BABAR results for other low energy exclusive hadronic processes are also discussed.

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

NASA Astrophysics Data System (ADS)

Manzo, C.; Paparo, D.; Marrucci, L.

2004-11-01

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.

Designing Free Energy Surfaces That Match Experimental Data with Metadynamics

DOE PAGES

White, Andrew D.; Dama, James F.; Voth, Gregory A.

2015-04-30

Creating models that are consistent with experimental data is essential in molecular modeling. This is often done by iteratively tuning the molecular force field of a simulation to match experimental data. An alternative method is to bias a simulation, leading to a hybrid model composed of the original force field and biasing terms. Previously we introduced such a method called experiment directed simulation (EDS). EDS minimally biases simulations to match average values. We also introduce a new method called experiment directed metadynamics (EDM) that creates minimal biases for matching entire free energy surfaces such as radial distribution functions and phi/psimore » angle free energies. It is also possible with EDM to create a tunable mixture of the experimental data and free energy of the unbiased ensemble with explicit ratios. EDM can be proven to be convergent, and we also present proof, via a maximum entropy argument, that the final bias is minimal and unique. Examples of its use are given in the construction of ensembles that follow a desired free energy. Finally, the example systems studied include a Lennard-Jones fluid made to match a radial distribution function, an atomistic model augmented with bioinformatics data, and a three-component electrolyte solution where ab initio simulation data is used to improve a classical empirical model.« less

Experimental energy resolution of a paracentric hemispherical deflector analyzer for different entry positions and bias

NASA Astrophysics Data System (ADS)

Dogan, M.; Ulu, M.; Gennarakis, G. G.; Zouros, T. J. M.

2013-04-01

A specially designed hemispherical deflector analyzer (HDA) with 5-element input lens having a movable entry position R0 suitable for electron energy analysis in atomic collisions was constructed and tested. The energy resolution of the HDA was experimentally determined for three different entry positions R0 = 84, 100, 112 mm as a function of the nominal entry potential V(R0) under pre-retardation conditions. The resolution for the (conventional) entry at the mean radius R0 = 100 mm was found to be a factor of 1.6-2 times worse than the resolution for the two (paracentric) positions R0 = 84 and 112 mm at particular values of V(R0). These results provide the first experimental verification and a proof of principle of the utility of such a paracentric HDA, while demonstrating its advantages over the conventional HDA: greater dispersion with reduced angular aberrations resulting in better energy resolution without the use of any additional fringing field correction electrodes. Supporting simulations of the entire lens plus HDA spectrometer are also provided and mostly found to be within 20%-30% of experimental values. The paracentric HDA is expected to provide a lower cost and/or more compact alternative to the conventional HDA particularly useful in modern applications utilizing a position sensitive detector.

Experimental energy resolution of a paracentric hemispherical deflector analyzer for different entry positions and bias.

PubMed

Dogan, M; Ulu, M; Gennarakis, G G; Zouros, T J M

2013-04-01

A specially designed hemispherical deflector analyzer (HDA) with 5-element input lens having a movable entry position R0 suitable for electron energy analysis in atomic collisions was constructed and tested. The energy resolution of the HDA was experimentally determined for three different entry positions R0 = 84, 100, 112 mm as a function of the nominal entry potential V(R0) under pre-retardation conditions. The resolution for the (conventional) entry at the mean radius R0 = 100 mm was found to be a factor of 1.6-2 times worse than the resolution for the two (paracentric) positions R0 = 84 and 112 mm at particular values of V(R0). These results provide the first experimental verification and a proof of principle of the utility of such a paracentric HDA, while demonstrating its advantages over the conventional HDA: greater dispersion with reduced angular aberrations resulting in better energy resolution without the use of any additional fringing field correction electrodes. Supporting simulations of the entire lens plus HDA spectrometer are also provided and mostly found to be within 20%-30% of experimental values. The paracentric HDA is expected to provide a lower cost and∕or more compact alternative to the conventional HDA particularly useful in modern applications utilizing a position sensitive detector.

The 2.5 bit/detected photon demonstration program: Phase 2 and 3 experimental results

NASA Technical Reports Server (NTRS)

Katz, J.

1982-01-01

The experimental program for laboratory demonstration of and energy efficient optical communication channel operating at a rate of 2.5 bits/detected photon is described. Results of the uncoded PPM channel performance are presented. It is indicated that the throughput efficiency can be achieved not only with a Reed-Solomon code as originally predicted, but with a less complex code as well.

Experimental Characterization and Validation of Simultaneous Gust Alleviation and Energy Harvesting for Multifunctional Wing Spars

DTIC Science & Technology

2012-08-01

U0=15m/s,  Lv  =350m   Cloud Wind and Clear Sky Gust Simulation Using Dryden PSD* Harvested Energy from Normal Vibration (Red) to...energy control law based on limited energy constraints 4) Experimentally validated simultaneous energy harvesting and vibration control Summary...Experimental Characterization and Validation of Simultaneous Gust Alleviation and Energy Harvesting for Multifunctional Wing Spars AFOSR

Experimental and theoretical triple differential cross sections for electron-impact ionization of Ar (3p) for equal energy final state electrons

NASA Astrophysics Data System (ADS)

Amami, Sadek; Ozer, Zehra N.; Dogan, Mevlut; Yavuz, Murat; Varol, Onur; Madison, Don

2016-09-01

There have been several studies of electron-impact ionization of inert gases for asymmetric final state energy sharing and normally one electron has an energy significantly higher than the other. However, there have been relatively few studies examining equal energy final state electrons. Here we report experimental and theoretical triple differential cross sections for electron impact ionization of Ar (3p) for equal energy sharing of the outgoing electrons. Previous experimental results combined with some new measurements are compared with distorted wave born approximation (DWBA) results, DWBA results using the Ward-Macek (WM) approximation for the post collision interaction (PCI), and three-body distorted wave (3DW) which includes PCI without approximation. The results show that it is crucially important to include PCI in the calculation particularly for lower energies and that the WM approximation is valid only for high energies. The 3DW, on the other hand, is in reasonably good agreement with data down to fairly low energies.

Uncertainties and understanding of experimental and theoretical results regarding reactions forming heavy and superheavy nuclei

NASA Astrophysics Data System (ADS)

Giardina, G.; Mandaglio, G.; Nasirov, A. K.; Anastasi, A.; Curciarello, F.; Fazio, G.

2018-02-01

Experimental and theoretical results of the PCN fusion probability of reactants in the entrance channel and the Wsur survival probability against fission at deexcitation of the compound nucleus formed in heavy-ion collisions are discussed. The theoretical results for a set of nuclear reactions leading to formation of compound nuclei (CNs) with the charge number Z = 102- 122 reveal a strong sensitivity of PCN to the characteristics of colliding nuclei in the entrance channel, dynamics of the reaction mechanism, and excitation energy of the system. We discuss the validity of assumptions and procedures for analysis of experimental data, and also the limits of validity of theoretical results obtained by the use of phenomenological models. The comparison of results obtained in many investigated reactions reveals serious limits of validity of the data analysis and calculation procedures.

U.S. Department of Energy Reference Model Program RM1: Experimental Results.

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

Hill, Craig; Neary, Vincent Sinclair; Gunawan, Budi

The Reference Model Project (RMP), sponsored by the U.S. Department of Energy’s (DOE) Wind and Water Power Technologies Program within the Office of Energy Efficiency & Renewable Energy (EERE), aims at expediting industry growth and efficiency by providing nonproprietary Reference Models (RM) of MHK technology designs as study objects for opensource research and development (Neary et al. 2014a,b). As part of this program, MHK turbine models were tested in a large open channel facility at the University of Minnesota’s St. Anthony Falls Laboratory (UMN-SAFL). Reference Model 1 (RM1) is a 1:40 geometric scale dual-rotor axial flow horizontal axis device withmore » counter-rotating rotors, each with a rotor diameter dT = 0.5m. Precise blade angular position and torque measurements were synchronized with three acoustic Doppler velocimeters (ADVs) aligned with each rotor and the midpoint for RM1. Flow conditions for each case were controlled such that depth, h = 1m, and volumetric flow rate, Qw = 2.425m3s-1, resulting in a hub height velocity of approximately Uhub = 1.05ms-1 and blade chord length Reynolds numbers of Rec ≈ 3.0x105. Vertical velocity profiles collected in the wake of each device from 1 to 10 rotor diameters are used to estimate the velocity recovery and turbulent characteristics in the wake, as well as the interaction of the counter-rotating rotor wakes. The development of this high resolution laboratory investigation provides a robust dataset that enables assessing turbulence performance models and their ability to accurately predict device performance metrics, including computational fluid dynamics (CFD) models that can be used to predict turbulent inflow environments, reproduce wake velocity deficit, recovery and higher order turbulent statistics, as well as device performance metrics.« less

Experimental Energy Levels and Partition Function of the 12C2 Molecule

NASA Astrophysics Data System (ADS)

Furtenbacher, Tibor; Szabó, István; Császár, Attila G.; Bernath, Peter F.; Yurchenko, Sergei N.; Tennyson, Jonathan

2016-06-01

The carbon dimer, the 12C2 molecule, is ubiquitous in astronomical environments. Experimental-quality rovibronic energy levels are reported for 12C2, based on rovibronic transitions measured for and among its singlet, triplet, and quintet electronic states, reported in 42 publications. The determination utilizes the Measured Active Rotational-Vibrational Energy Levels (MARVEL) technique. The 23,343 transitions measured experimentally and validated within this study determine 5699 rovibronic energy levels, 1325, 4309, and 65 levels for the singlet, triplet, and quintet states investigated, respectively. The MARVEL analysis provides rovibronic energies for six singlet, six triplet, and two quintet electronic states. For example, the lowest measurable energy level of the {{a}}{}3{{{\\Pi }}}{{u}} state, corresponding to the J = 2 total angular momentum quantum number and the F 1 spin-multiplet component, is 603.817(5) cm-1. This well-determined energy difference should facilitate observations of singlet-triplet intercombination lines, which are thought to occur in the interstellar medium and comets. The large number of highly accurate and clearly labeled transitions that can be derived by combining MARVEL energy levels with computed temperature-dependent intensities should help a number of astrophysical observations as well as corresponding laboratory measurements. The experimental rovibronic energy levels, augmented, where needed, with ab initio variational ones based on empirically adjusted and spin-orbit coupled potential energy curves obtained using the Duo code, are used to obtain a highly accurate partition function, and related thermodynamic data, for 12C2 up to 4000 K.

Characterisation and optimisation of flexible transfer lines for liquid helium. Part I: Experimental results

NASA Astrophysics Data System (ADS)

Dittmar, N.; Haberstroh, Ch.; Hesse, U.; Krzyzowski, M.

2016-04-01

The transfer of liquid helium (LHe) into mobile dewars or transport vessels is a common and unavoidable process at LHe decant stations. During this transfer reasonable amounts of LHe evaporate due to heat leak and pressure drop. Thus generated helium gas needs to be collected and reliquefied which requires a huge amount of electrical energy. Therefore, the design of transfer lines used at LHe decant stations has been optimised to establish a LHe transfer with minor evaporation losses which increases the overall efficiency and capacity of LHe decant stations. This paper presents the experimental results achieved during the thermohydraulic optimisation of a flexible LHe transfer line. An extensive measurement campaign with a set of dedicated transfer lines equipped with pressure and temperature sensors led to unique experimental data of this specific transfer process. The experimental results cover the heat leak, the pressure drop, the transfer rate, the outlet quality, and the cool-down and warm-up behaviour of the examined transfer lines. Based on the obtained results the design of the considered flexible transfer line has been optimised, featuring reduced heat leak and pressure drop.

Experimental simulation of radiation damage of polymers in space applications by cosmic-ray-type high energy heavy ions and the resulting changes in optical properties

NASA Astrophysics Data System (ADS)

Hossain, U. H.; Ensinger, W.

2015-12-01

Devices operating in space, e.g. in satellites, are being hit by cosmic rays. These include so-called HZE-ions, with High mass (Z) and energy (E). These highly energetic heavy ions penetrate deeply into the materials and deposit a large amount of energy, typically several keV per nm range. Serious damage is created. In space vehicles, polymers are used which are degraded under ion bombardment. HZE ion irradiation can experimentally be simulated in large scale accelerators. In the present study, the radiation damage of aliphatic vinyl- and fluoro-polymers by heavy ions with energies in the GeV range is described. The ions cause bond scission and create volatile small molecular species, leading to considerable mass loss of the polymers. Since hydrogen, oxygen and fluorine-containing molecules are created and these elements are depleted, the remaining material is carbon-richer than the original polymers and contains conjugated CC double bonds. This process is investigated by measuring the optical band gap with UV-Vis absorption spectrometry as a function of ion fluence. The results show how the optical band gaps shift from the UV into the Vis region upon ion irradiation for the different polymers.

U.S. Department of Energy Reference Model Program RM2: Experimental Results

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

Hill, Craig; Neary, Vincent Sinclair; Gunawan, Budi

2014-08-01

The Reference Model Project (RMP), sponsored by the U.S. Department of Energy’s (DOE) Wind and Water Power Technologies Program within the Office of Energy Efficiency & Renewable Energy (EERE), aims at expediting industry growth and efficiency by providing non-proprietary Reference Models (RM) of MHK technology designs as study objects for open-source research and development (Neary et al. 2014a,b). As part of this program, MHK turbine models were tested in a large open channel facility at the University of Minnesota’s St. Anthony Falls Laboratory (UMN - SAFL) . Reference Model 2 (RM2) is a 1:15 geometric scale dual - rotor crossmore » flow vertical axis device with counter - rotating rotors, each with a rotor diameter d T = 0.43m and rotor height, h T = 0.323 m. RM2 is a river turbine designed for a site modeled after a reach in the lower Mississippi River near Baton Rouge, Louisiana (Barone et al. 2014) . Precise blade angular position and torque measurements were synchronized with three acoustic Doppler velocimeters (ADV) aligned with each rotor and the midpoint for RM2 . Flow conditions for each case were controlled such that depth, h = 1m, and volumetric flow rate, Q w = 2. 35m 3s -1 , resulting in a hub height velocity of approximately U hub = 1. 2 ms -1 and blade chord length Reynolds numbers of Re c = 6 .1x10 4. Vertical velocity profiles collected in the wake of each device from 1 to 10 rotor diameters are used to estimate the velocity recovery and turbulent characteristics in the wake, as well as the interaction of the counter-rotating rotor wakes. The development of this high resolution laboratory investigation provides a robust dataset that enables assessing computational fluid dynamics (CFD) models and their ability to accurately simulate turbulent inflow environments, device performance metrics, and to reproduce wake velocity deficit, recovery and higher order turbulent statistics.« less

Density functional theory and an experimentally-designed energy functional of electron density.

PubMed

Miranda, David A; Bueno, Paulo R

2016-09-21

We herein demonstrate that capacitance spectroscopy (CS) experimentally allows access to the energy associated with the quantum mechanical ground state of many-electron systems. Priorly, electrochemical capacitance, C [small mu, Greek, macron] [ρ], was previously understood from conceptual and computational density functional theory (DFT) calculations. Thus, we herein propose a quantum mechanical experiment-based variational method for electron charging processes based on an experimentally-designed functional of the ground state electron density. In this methodology, the electron state density, ρ, and an energy functional of the electron density, E [small mu, Greek, macron] [ρ], can be obtained from CS data. CS allows the derivative of the electrochemical potential with respect to the electron density, (δ[small mu, Greek, macron][ρ]/δρ), to be obtained as a unique functional of the energetically minimised system, i.e., β/C [small mu, Greek, macron] [ρ], where β is a constant (associated with the size of the system) and C [small mu, Greek, macron] [ρ] is an experimentally observable quantity. Thus the ground state energy (at a given fixed external potential) can be obtained simply as E [small mu, Greek, macron] [ρ], from the experimental measurement of C [small mu, Greek, macron] [ρ]. An experimental data-set was interpreted to demonstrate the potential of this quantum mechanical experiment-based variational principle.

Blanking and piercing theory, applications and recent experimental results

NASA Astrophysics Data System (ADS)

Zaid, Adnan l. O.

2014-06-01

Blanking and piercing are manufacturing processes by which certain geometrical shapes are sheared off a sheet metal. If the sheared off part is the one required, the processes referred to as blanking and if the remaining part in the sheet is the one required, the process is referred to as piercing. In this paper, the theory and practice of these processes are reviewed and discussed The main parameters affecting these processes are presented and discussed. These include: the radial clearance percentage, punch and die geometrical parameters, for example punch and die profile radii. The abovementioned parameters on the force and energy required to effect blanking together with their effect on the quality of the products are also presented and discussed. Recent experimental results together with photomacrographs and photomicrographs are also included and discussed. Finally, the effect of punch and die wear on the quality of the blanks is alsogiven and discussed.

An Experimental Study of Energy Consumption in Buildings Providing Ancillary Services

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

Lin, Yashen; Afshari, Sina; Wolfe, John

Heating, ventilation, and air conditioning (HVAC) systems in commercial buildings can provide ancillary services (AS) to the power grid, but by providing AS their energy consumption may increase. This inefficiency is evaluated using round-trip efficiency (RTE), which is defined as the ratio between the decrease and the increase in the HVAC system's energy consumption compared to the baseline consumption as a result of providing AS. This paper evaluates the RTE of a 30,000 m2 commercial building providing AS. We propose two methods to estimate the HVAC system's settling time after an AS event based on temperature and the air flowmore » measurements from the building. Experimental data gathered over a 4-month period are used to calculate the RTE for AS signals of various waveforms, magnitudes, durations, and polarities. The results indicate that the settling time estimation algorithm based on the air flow measurements obtains more accurate results compared to the temperature-based algorithm. Further, we study the impact of the AS signal shape parameters on the RTE and discuss the practical implications of our findings.« less

Experimental investigation of a packed bed thermal energy storage system

NASA Astrophysics Data System (ADS)

Cascetta, Mario; Cau, Giorgio; Puddu, Pierpaolo; Serra, Fabio

2015-11-01

In this work experimental investigations on a thermal energy storage system with a solid material as storage media and air as heat transfer fluid will be presented. The experimental test rig, installed at the DIMCM of the University of Cagliari, consists of a carbon steel tank filled with freely poured alumina beads that allows investigations of heat transfer phenomena in packed beds. The aim of this work is to show the influence of the operating conditions and physical parameters on thermocline formation and, in particular, the thermal behaviour of the thermal energy storage for repeated charging and discharging cycles. Better charging efficiency is obtained for lower values of mass flow rate and maximum air temperature and for increasing aspect ratio. A decreasing influence of the metal wall with continuous operation is also highlighted. In conclusion, the analysis focuses on the thermal hysteresis phenomenon, which causes degradation of the thermocline and the reduction of the energy that can be stored by the accumulator as the repeated number of cycles increases.

Quantum memories with zero-energy Majorana modes and experimental constraints

NASA Astrophysics Data System (ADS)

Ippoliti, Matteo; Rizzi, Matteo; Giovannetti, Vittorio; Mazza, Leonardo

2016-06-01

In this work we address the problem of realizing a reliable quantum memory based on zero-energy Majorana modes in the presence of experimental constraints on the operations aimed at recovering the information. In particular, we characterize the best recovery operation acting only on the zero-energy Majorana modes and the memory fidelity that can be therewith achieved. In order to understand the effect of such restriction, we discuss two examples of noise models acting on the topological system and compare the amount of information that can be recovered by accessing either the whole system, or the zero modes only, with particular attention to the scaling with the size of the system and the energy gap. We explicitly discuss the case of a thermal bosonic environment inducing a parity-preserving Markovian dynamics in which the memory fidelity achievable via a read-out of the zero modes decays exponentially in time, independent from system size. We argue, however, that even in the presence of said experimental limitations, the Hamiltonian gap is still beneficial to the storage of information.

Implications of the experimental results on high energy cosmic rays with regard to their origin

NASA Technical Reports Server (NTRS)

Fichtel, C. E.; Linsley, J.

1985-01-01

It was shown in an earlier report that current cosmic ray evidence supports a change in the cosmic ray composition in the region between 10 to the 6th power and 10 to the 8th power GeV total energy in the direction of a smaller average value of A. Compared to normal celestial abundances, the heavy nuclei are much less abundant, and, in fact, the composition measurements above 10 to the 8th power GeV are consistent with there being only protons. Here, these results combined with those of the energy spectrum and anisotropy of the comsic rays and other astrophysical information will be examined to try to determine their implications for the origin of the cosmic rays. In this paper, consideration is given to the implications of one or more than one type of source in the galaxy to see which are consistent with the interpretation of current measurements. The nature of the source types that would be required are discussed.

Experimental and numerical investigation of a packed-bed thermal energy storage device

NASA Astrophysics Data System (ADS)

Yang, Bei; Wang, Yan; Bai, Fengwu; Wang, Zhifeng

2017-06-01

This paper presents a pilot-scale setup built to study a packed bed thermal energy storage device based on ceramic balls randomly poured into a cylindrical tank while using air as heat transfer fluid. Temperature distribution of ceramic balls throughout the packed bed is investigated both experimentally and numerically. Method of characteristic is adopted to improve the numerical computing efficiency, and mesh independence is verified to guarantee the accuracy of numerical solutions and the economy of computing time cost at the same time. Temperature in tests is as high as over 600 °C, and modeling prediction shows good agreements with experimental results under various testing conditions when heat loss is included and thermal properties of air are considered as temperature dependent.

Experimental Studies of Elementary Particle Interactions at High Energies

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

Goulianos, Konstantin

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 itsmore » 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

Performance analysis of hybrid vibrational energy harvesters with experimental verification

NASA Astrophysics Data System (ADS)

Sriramdas, Rammohan; Pratap, Rudra

2018-07-01

In the present work, performance indices for a hybrid energy harvester (HEH) that is composed of piezoelectric and electrodynamic or electromagnetic mechanisms of energy conversion are analyzed. Performance of a HEH is defined in terms of Q-normalized power factor and efficiency of conversion. They are observed to acutely depend on coupling strength or figures of merit in both piezoelectric and electrodynamic domains. The influence of figures of merit on the Q-normalized power factor, and the limits of conversion efficiency are explored. Based on the studies, a suitable range for figures of merit that would maximize both Q-normalized power factor and conversion efficiency in hybrid harvesters is proposed. The proposed idea is verified experimentally for the appropriate values of figures of merit and efficiencies by fabricating and testing four experimental models of the HEHs.

Theoretical modeling, simulation and experimental study of hybrid piezoelectric and electromagnetic energy harvester

NASA Astrophysics Data System (ADS)

Li, Ping; Gao, Shiqiao; Cong, Binglong

2018-03-01

In this paper, performances of vibration energy harvester combined piezoelectric (PE) and electromagnetic (EM) mechanism are studied by theoretical analysis, simulation and experimental test. For the designed harvester, electromechanical coupling modeling is established, and expressions of vibration response, output voltage, current and power are derived. Then, performances of the harvester are simulated and tested; moreover, the power charging rechargeable battery is realized through designed energy storage circuit. By the results, it's found that compared with piezoelectric-only and electromagnetic-only energy harvester, the hybrid energy harvester can enhance the output power and harvesting efficiency; furthermore, at the harmonic excitation, output power of harvester linearly increases with acceleration amplitude increasing; while it enhances with acceleration spectral density increasing at the random excitation. In addition, the bigger coupling strength, the bigger output power is, and there is the optimal load resistance to make the harvester output the maximal power.

Experimental Evaluation of Energy Efficiency for a Soft Wearable Robotic Suit.

PubMed

Jin, Shanhai; Iwamoto, Noriyasu; Hashimoto, Kazunobu; Yamamoto, Motoji

2016-10-12

This paper presents a new soft wearable robotic suit for energy-efficient walking in daily activities for elderly persons. The presented robotic suit provides a small yet effective assistive force for hip flexion through winding belts that include elastic elements. In addition, it does not restrict the range of movement in the lower limbs. Moreover, its structure is simple and lightweight, and thus wearers can easily take the device on and off by themselves. Experimental results on nine elderly subjects (age = 74.23.7 years) show that the robotic suit worn and powered on (PON) significantly reduced energy expenditure by an average of 5.9 % compared with the condition of worn but powered off (POFF). Furthermore, compared with the POFF condition, there was a significant improvement in gait characteristics in the PON condition for all subjects.

Experimental verification and optimization of a linear electromagnetic energy harvesting device

NASA Astrophysics Data System (ADS)

Mullen, Christopher; Lee, Soobum

2017-04-01

Implementation of energy harvesting technology can provide a sustainable, remote power source for soldiers by reducing the battery weight and allowing them to stay in the field for longer periods of time. Among multiple energy conversion principles, electromagnetic induction can scavenge energy from wasted kinematic and vibration energy found from human motion. Hip displacement during human gait acts as a base excitation for an energy harvesting backpack system. The placement of a permanent magnet in this vibration environment results in relative motion of the magnet to the coil of copper wire, which induces an electric current. This current can be saved to a battery or capacitor bank installed on the backpack to be used to power electronic devices. The purpose of this research is to construct a reliable simulation model for an electromagnetic vibration energy harvester and use it for a multi-variable optimization algorithm to identify an optimal coil and magnet layout for highest power output. Key components of the coupled equations of motion such as the magnetic flux density and coil inductance are obtained using ANSYS multi-physics software or by measuring them. These components are fed into a harvester simulation model (e.g. coupled field equations of motion for the backpack harvester) that generates the electrical power output. The developed simulation model is verified with a case study including an experimental test. Then the optimal design parameters in the simulation model (e.g., magnet layout, coil width, outer coil diameter, external load resistance) are identified for maximum power. Results from this study will pave the way for a more efficient energy harvesting backpack while providing better insight into the efficiency of magnet and coil layout for electromagnetic applications.

Experimental demonstration of photon upconversion via cooperative energy pooling

PubMed Central

Weingarten, Daniel H.; LaCount, Michael D.; van de Lagemaat, Jao; Rumbles, Garry; Lusk, Mark T.; Shaheen, Sean E.

2017-01-01

Photon upconversion is a fundamental interaction of light and matter that has applications in fields ranging from bioimaging to microfabrication. However, all photon upconversion methods demonstrated thus far involve challenging aspects, including requirements of high excitation intensities, degradation in ambient air, requirements of exotic materials or phases, or involvement of inherent energy loss processes. Here we experimentally demonstrate a mechanism of photon upconversion in a thin film, binary mixture of organic chromophores that provides a pathway to overcoming the aforementioned disadvantages. This singlet-based process, called Cooperative Energy Pooling (CEP), utilizes a sensitizer-acceptor design in which multiple photoexcited sensitizers resonantly and simultaneously transfer their energies to a higher-energy state on a single acceptor. Data from this proof-of-concept implementation is fit by a proposed model of the CEP process. Design guidelines are presented to facilitate further research and development of more optimized CEP systems. PMID:28294129

Experimental demonstration of photon upconversion via cooperative energy pooling

NASA Astrophysics Data System (ADS)

Weingarten, Daniel H.; Lacount, Michael D.; van de Lagemaat, Jao; Rumbles, Garry; Lusk, Mark T.; Shaheen, Sean E.

2017-03-01

Photon upconversion is a fundamental interaction of light and matter that has applications in fields ranging from bioimaging to microfabrication. However, all photon upconversion methods demonstrated thus far involve challenging aspects, including requirements of high excitation intensities, degradation in ambient air, requirements of exotic materials or phases, or involvement of inherent energy loss processes. Here we experimentally demonstrate a mechanism of photon upconversion in a thin film, binary mixture of organic chromophores that provides a pathway to overcoming the aforementioned disadvantages. This singlet-based process, called Cooperative Energy Pooling (CEP), utilizes a sensitizer-acceptor design in which multiple photoexcited sensitizers resonantly and simultaneously transfer their energies to a higher-energy state on a single acceptor. Data from this proof-of-concept implementation is fit by a proposed model of the CEP process. Design guidelines are presented to facilitate further research and development of more optimized CEP systems.

Combined experimental and numerical investigation of energy harness utilizing vortex induced vibration over half cylinder using piezoelectric beams

NASA Astrophysics Data System (ADS)

Ahmed, Md. Tusher; Hossain, Md. Tanver; Rahman, Md. Ashiqur

2017-06-01

Energy harvesting technology has the ability to create self-powered electronic systems that do not rely on battery power for their operation. Wind energy can be converted into electricity via a piezoelectric transducer during the air flow over a cylinder. The vortex-induced vibration over the cylinder causes the piezoelectric beam to vibrate. Thus useful electric energy at the range 0.2-0.3V is found which can be useful for self-powering small electronic devices. In the present study, prototypes of micro-energy harvester with a shape of 65 mm × 37 mm × 0.4 mm are developed and tested for airflow over D-shaped bluff body for diameters of 15, 20 and 28mm in an experimental setup consisting of a long wind tunnel of 57cm × 57cm with variable speeds of the motor for different flow velocities and the experimental setup is connected at the downstream where flow velocity is the maximum. Experimental results show that the velocity and induced voltage follows a regular linear pattern. A maximum electrical potential of 140 mV for velocity of 1.1 ms-1 at a bluff body diameter of 15 mm is observed in the energy harvester that can be applied in many practical cases for self-powering electronic devices. The simulation of this energy harvesting phenomena is then simulated using COMSOLE multi-physics. Diameter of the bluff bodies as well as flow velocity and size of cantilever beam are varied and the experimental findings are found to be in good agreement with the simulated ones. The simulations along with the experimental data show the possibility of generating electricity from vortex induced vibration and can be applied in many practical cases for self-powering electronic devices.

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

PubMed

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

2017-01-01

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

Fuel-rich, catalytic reaction experimental results

NASA Technical Reports Server (NTRS)

Rollbuhler, R. James

1991-01-01

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.

A critical review of RHIC experimental results

NASA Astrophysics Data System (ADS)

Trainor, Thomas A.

2014-07-01

The relativistic heavy-ion collider (RHIC) was constructed to achieve an asymptotic state of nuclear matter in heavy-ion collisions, a near-ideal gas of deconfined quarks and gluons denoted quark-gluon plasma or QGP. RHIC collisions are indeed very different from the hadronic processes observed at the Bevalac and AGS, but high-energy elementary-collision mechanisms are also non-hadronic. The two-component model (TCM) combines measured properties of elementary collisions with the Glauber eikonal model to provide an alternative asymptotic limit for A-A collisions. RHIC data have been interpreted to indicate formation of a strongly-coupled QGP (sQGP) or "perfect liquid". In this review, I consider the experimental evidence that seems to support such conclusions and alternative evidence that may conflict with those conclusions and suggest different interpretations.

Experimental results on atomic oxygen corrosion of silver

NASA Technical Reports Server (NTRS)

Fromhold, Albert T.

1988-01-01

The results of an experimental study of the reaction kinetics of silver with atomic oxygen in 10 degree increments over the temperature range of 0 to 70 C is reported. The silver specimens, of the order of 10,000 A in thickness, were prepared by thermal evaporation onto 3 inch diameter polished silicon wafers. There were later sliced into pieces having surface areas of the order of 1/4 to 1/2 square inch. Atomic oxygen was generated by a gas discharge in a commercial plasmod asher operating in the megahertz frequency range. The sample temperature within the chamber was controlled by means of a thermoelectric unit. Exposure of the silver specimens to atomic oxygen was incremental, with oxide film thickness measurements being carried out between exposures by means of an automated ellipsometer. For the early growth phase, the data can be described satisfactorily by a logarithmic growth law: the oxide film thickness increases as the logarithm of the exposure time. Furthermore, the oxidation process is thermally activated, the rate increasing with increasing temperature. However, the empirical activation energy parameter deduced from Arrhenius plots is quite low, being of the order of 0.1 eV.

A theoretical model of the application of RF energy to the airway wall and its experimental validation.

PubMed

Jarrard, Jerry; Wizeman, Bill; Brown, Robert H; Mitzner, Wayne

2010-11-27

Bronchial thermoplasty is a novel technique designed to reduce an airway's ability to contract by reducing the amount of airway smooth muscle through controlled heating of the airway wall. This method has been examined in animal models and as a treatment for asthma in human subjects. At the present time, there has been little research published about how radiofrequency (RF) energy and heat is transferred to the airways of the lung during bronchial thermoplasty procedures. In this manuscript we describe a computational, theoretical model of the delivery of RF energy to the airway wall. An electro-thermal finite-element-analysis model was designed to simulate the delivery of temperature controlled RF energy to airway walls of the in vivo lung. The model includes predictions of heat generation due to RF joule heating and transfer of heat within an airway wall due to thermal conduction. To implement the model, we use known physical characteristics and dimensions of the airway and lung tissues. The model predictions were tested with measurements of temperature, impedance, energy, and power in an experimental canine model. Model predictions of electrode temperature, voltage, and current, along with tissue impedance and delivered energy were compared to experiment measurements and were within ± 5% of experimental averages taken over 157 sample activations.The experimental results show remarkable agreement with the model predictions, and thus validate the use of this model to predict the heat generation and transfer within the airway wall following bronchial thermoplasty. The model also demonstrated the importance of evaporation as a loss term that affected both electrical measurements and heat distribution. The model predictions showed excellent agreement with the empirical results, and thus support using the model to develop the next generation of devices for bronchial thermoplasty. Our results suggest that comparing model results to RF generator electrical measurements

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

ERIC Educational Resources Information Center

Precker, Jurgen W.

2007-01-01

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…

Experimental design to generate strong shear layers in a high-energy-density plasma

NASA Astrophysics Data System (ADS)

Harding, E. C.; Drake, R. P.; Aglitskiy, Y.; Gillespie, R. S.; Grosskopf, M. J.; Weaver, J. L.; Velikovich, A. L.; Visco, A.; Ditmar, J. R.

2010-06-01

The development of a new experimental system for generating a strong shear flow in a high-energy-density plasma is described in detail. The targets were designed with the goal of producing a diagnosable Kelvin-Helmholtz (KH) instability, which plays an important role in the transition turbulence but remains relatively unexplored in the high-energy-density regime. To generate the shear flow the Nike laser was used to drive a flow of Al plasma over a low-density foam surface with an initial perturbation. The interaction of the Al and foam was captured with a spherical crystal imager using 1.86 keV X-rays. The selection of the individual targets components is discussed and results are presented.

Experimental Verification of the Individual Energy Dependencies of the Partial L-Shell Photoionization Cross Sections of Pd and Mo

NASA Astrophysics Data System (ADS)

Hönicke, Philipp; Kolbe, Michael; Müller, Matthias; Mantler, Michael; Krämer, Markus; Beckhoff, Burkhard

2014-10-01

An experimental method for the verification of the individually different energy dependencies of L1-, L2-, and L3- subshell photoionization cross sections is described. The results obtained for Pd and Mo are well in line with theory regarding both energy dependency and absolute values, and confirm the theoretically calculated cross sections by Scofield from the early 1970 s and, partially, more recent data by Trzhaskovskaya, Nefedov, and Yarzhemsky. The data also demonstrate the questionability of quantitative x-ray spectroscopical results based on the widely used fixed jump ratio approximated cross sections with energy independent ratios. The experiments are carried out by employing the radiometrically calibrated instrumentation of the Physikalisch-Technische Bundesanstalt at the electron storage ring BESSY II in Berlin; the obtained fluorescent intensities are thereby calibrated at an absolute level in reference to the International System of Units. Experimentally determined fixed fluorescence line ratios for each subshell are used for a reliable deconvolution of overlapping fluorescence lines. The relevant fundamental parameters of Mo and Pd are also determined experimentally in order to calculate the subshell photoionization cross sections independently of any database.

Experimental Investigations of the Energy and Environmental Indices of Operation of a Low-Capacity Combined Gas Producer and Hot-Water Boiler

NASA Astrophysics Data System (ADS)

Bodnar, L. A.; Stepanov, D. V.; Dovgal‧, A. N.

2015-07-01

It has been shown that the introduction of combined gas producers and boilers on renewable energy sources is a pressing issue. A structural diagram of a low-capacity combined gas producer and boiler on renewable energy sources has been given; a bench and procedures for investigation and processing of results have been developed. Experimental investigations of the energy and environmental indices of a 40-kW combined gas producer and hotwater boiler burning wood have been carried out. Results of the experimental investigations have been analyzed. Distinctive features have been established and a procedure of thermal calculation of the double furnace of a lowcapacity combined gas producer and boiler burning solid fuel has been proposed. The calculated coefficients of heat transfer from the gases in the convection bank have been compared with the obtained experimental results. A calculation dependence for the heat transfer from the gases in convection banks of low-capacity hot-water boilers has been proposed. The quantities of harmful emissions from the combined gas producer and boiler on renewable energy sources have been compared with the existing Ukrainian and foreign standards. It has been established that the environmental efficiency of the boiler under study complies with most of the standard requirements of European countries.

Direct Measurements of Quantum Kinetic Energy Tensor in Stable and Metastable Water near the Triple Point: An Experimental Benchmark.

PubMed

Andreani, Carla; Romanelli, Giovanni; Senesi, Roberto

2016-06-16

This study presents the first direct and quantitative measurement of the nuclear momentum distribution anisotropy and the quantum kinetic energy tensor in stable and metastable (supercooled) water near its triple point, using deep inelastic neutron scattering (DINS). From the experimental spectra, accurate line shapes of the hydrogen momentum distributions are derived using an anisotropic Gaussian and a model-independent framework. The experimental results, benchmarked with those obtained for the solid phase, provide the state of the art directional values of the hydrogen mean kinetic energy in metastable water. The determinations of the direction kinetic energies in the supercooled phase, provide accurate and quantitative measurements of these dynamical observables in metastable and stable phases, that is, key insight in the physical mechanisms of the hydrogen quantum state in both disordered and polycrystalline systems. The remarkable findings of this study establish novel insight into further expand the capacity and accuracy of DINS investigations of the nuclear quantum effects in water and represent reference experimental values for theoretical investigations.

Experimental Cross Sections of Fission Fragments of Thorium-232 Irradiated with Medium-Energy Protons

NASA Astrophysics Data System (ADS)

Libanova, O. N.; Golubeva, E. S.; Ermolaev, S. V.; Matushko, V. L.; Botvina, A. S.

2018-05-01

This paper is focused on fission of Th-232 nuclei induced by protons with energies ranging from 20 to 140 MeV. This energy range is the most informative for studying the competition between asymmetric and symmetric fission modes. Experimental cross sections of production of radionuclides in thorium targets have been determined a year after irradiation. The corresponding theoretical values are calculated using the cascade-evaporation-fission model. The theoretical and experimental cross sections (literature data included) are compared.

Comparison the Results of Numerical Simulation And Experimental Results for Amirkabir Plasma Focus Facility

NASA Astrophysics Data System (ADS)

Goudarzi, Shervin; Amrollahi, R.; Niknam Sharak, M.

2014-06-01

In this paper the results of the numerical simulation for Amirkabir Mather-type Plasma Focus Facility (16 kV, 36μF and 115 nH) in several experiments with Argon as working gas at different working conditions (different discharge voltages and gas pressures) have been presented and compared with the experimental results. Two different models have been used for simulation: five-phase model of Lee and lumped parameter model of Gonzalez. It is seen that the results (optimum pressures and current signals) of the Lee model at different working conditions show better agreement than lumped parameter model with experimental values.

Experimental Summary: Very High Energy Cosmic Rays and their Interactions

NASA Astrophysics Data System (ADS)

Kampert, Karl-Heinz

2013-06-01

The XVII International Symposium on Very High Energy Cosmic Ray Interactions, held in August of 2012 in Berlin, was the first one in the history of the Symposium,where a plethora of high precision LHC data with relevance for cosmic ray physics was presented. This report aims at giving a brief summary of those measurements andit discusses their relevance for observations of high energy cosmic rays. Enormous progress has been made also in air shower observations and in direct measurements of cosmic rays, exhibiting many more structure in the cosmic ray energy spectrum than just a simple power law with a knee and an ankle. At the highest energy, the flux suppression may not be dominated by the GZK-effect but by the limiting energy of a nearby source or source population. New projects and application of new technologies promise further advances also in the near future. We shall discuss the experimental and theoretical progress in the field and its prospects for coming years.

Photoionization microscopy: Hydrogenic theory in semiparabolic coordinates and comparison with experimental results

NASA Astrophysics Data System (ADS)

Kalaitzis, P.; Danakas, S.; Lépine, F.; Bordas, C.; Cohen, S.

2018-05-01

Photoionization microscopy (PM) is an experimental method allowing for high-resolution measurements of the electron current probability density in the case of photoionization of an atom in an external uniform static electric field. PM is based on high-resolution velocity-map imaging and offers the unique opportunity to observe the quantum oscillatory spatial structure of the outgoing electron flux. We present the basic elements of the quantum-mechanical theoretical framework of PM for hydrogenic systems near threshold. Our development is based on the computationally more convenient semiparabolic coordinate system. Theoretical results are first subjected to a quantitative comparison with hydrogenic images corresponding to quasibound states and a qualitative comparison with nonresonant images of multielectron atoms. Subsequently, particular attention is paid on the structure of the electron's momentum distribution transversely to the static field (i.e., of the angularly integrated differential cross-section as a function of electron energy and radius of impact on the detector). Such 2D maps provide at a glance a complete picture of the peculiarities of the differential cross-section over the entire near-threshold energy range. Hydrogenic transverse momentum distributions are computed for the cases of the ground and excited initial states and single- and two-photon ionization schemes. Their characteristics of general nature are identified by comparing the hydrogenic distributions among themselves, as well as with a presently recorded experimental distribution concerning the magnesium atom. Finally, specificities attributed to different target atoms, initial states, and excitation scenarios are also discussed, along with directions of further work.

Preliminary experimental results of tungsten wire-array Z-pinches on primary test stand

NASA Astrophysics Data System (ADS)

Huang, Xian-Bin; Zhou, Shao-Tong; Dan, Jia-Kun; Ren, Xiao-Dong; Wang, Kun-Lun; Zhang, Si-Qun; Li, Jing; Xu, Qiang; Cai, Hong-Chun; Duan, Shu-Chao; Ouyang, Kai; Chen, Guang-Hua; Ji, Ce; Wei, Bing; Feng, Shu-Ping; Wang, Meng; Xie, Wei-Ping; Deng, Jian-Jun; Zhou, Xiu-Wen; Yang, Yi

2015-07-01

The Primary Test Stand (PTS) developed at the China Academy of Engineering Physics is a 20 TW 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. Preliminary 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 13 mm to 30 mm, consisting of 132-300 tungsten wires with 5-10 μm in diameter. Multiple diagnostics were fielded to characterize the x-ray radiation from wire-array Z pinches. The x-ray peak power (˜50 TW) and total radiated energy (˜500 kJ) were obtained from a single 20-mm-diam array with 80-ns stagnation time. The highest x-ray peak power up to 80 TW with 2.4 ns FWHM was achieved by using a nested array with 20-mm outer diameter, and the total x-ray energy from the nested array is comparable to that of single array. Implosion velocity estimated from the time-resolved image measurement exceeds 30 cm/μs. The detailed experimental results and other findings are presented and discussed.

Experimental And Theoretical High Energy Physics Research At UCLA

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

Cousins, Robert D.

2013-07-22

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 describesmore » 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.« less

A Comparison of the ab Initio Calculated and Experimental Conformational Energies of Alkylcyclohexanes

NASA Astrophysics Data System (ADS)

Freeman, Fillmore; Tsegai, Zufan M.; Kasner, Marc L.; Hehre, Warren J.

2000-05-01

Ab initio 6-31G(d) and MP2/6-31G(d)//6-31G(d) methods were used to calculate the energies of the rotamers of the chair conformers of alkylcyclohexanes and trimethylsilylcyclohexane. The MP2/6-31G(d)//6-31G(d) calculated conformational energies ( ? or A values, in kcal/mol) of the alkylcyclohexanes (Me = 1.96; Et = 1.80; Pr = 1.73 iso-Pr = 1.60; t-Bu = 5.45; neo-pent = 1.32) and trimethylsilylcyclohexane (SiMe3 = 2.69) are similar to the experimental values. Plots of the calculated conformational energies for the alkylcyclohexanes and trimethylsilylcyclohexane versus their experimental values are linear (slope = 1.253 and r = .993 for 6-31G(d) and slope = 1.114 and r = .982 for MP2/6-31G(d)//6-31G(d)). The conformational energies are determined primarily by steric effects which include gauche (synclinal) interactions and repulsive nonbonded interactions in both the axial and equatorial conformers.

Influences of Electromagnetic Energy on Bio-Energy Transport through Protein Molecules in Living Systems and Its Experimental Evidence.

PubMed

Pang, Xiaofeng; Chen, Shude; Wang, Xianghui; Zhong, Lisheng

2016-07-25

The influences of electromagnetic fields (EMFs) on bio-energy transport and its mechanism of changes are investigated through analytic and numerical simulation and experimentation. Bio-energy transport along protein molecules is performed by soliton movement caused by the dipole-dipole electric interactions between neighboring amino acid residues. As such, EMFs can affect the structure of protein molecules and change the properties of the bio-energy transported in living systems. This mechanism of biological effect from EMFs involves the amino acid residues in protein molecules. To study and reveal this mechanism, we simulated numerically the features of the movement of solitons along protein molecules with both a single chain and with three channels by using the Runge-Kutta method and Pang's soliton model under the action of EMFs with the strengths of 25,500, 51,000, 76,500, and 102,000 V/m in the single-chain protein, as well as 17,000, 25,500, and 34,000 V/m in the three-chain protein, respectively. Results indicate that electric fields (EFs) depress the binding energy of the soliton, decrease its amplitude, and change its wave form. Also, the soliton disperses at 102,000 V/m in a single-chain protein and at 25,500 and 34,000 V/m in three-chain proteins. These findings signify that the influence of EMFs on the bio-energy transport cannot be neglected; however, these variations depend on both the strength and the direction of the EF in the EMF. This direction influences the biological effects of EMF, which decrease with increases in the angle between the direction of the EF and that of the dipole moment of amino acid residues; however, randomness at the macroscopic level remains. Lastly, we experimentally confirm the existence of a soliton and the validity of our conclusion by using the infrared spectra of absorption of the collagens, which is activated by another type of EF. Thus, we can affirm that both the described mechanism and the corresponding theory are

Influences of Electromagnetic Energy on Bio-Energy Transport through Protein Molecules in Living Systems and Its Experimental Evidence

PubMed Central

Pang, Xiaofeng; Chen, Shude; Wang, Xianghui; Zhong, Lisheng

2016-01-01

The influences of electromagnetic fields (EMFs) on bio-energy transport and its mechanism of changes are investigated through analytic and numerical simulation and experimentation. Bio-energy transport along protein molecules is performed by soliton movement caused by the dipole–dipole electric interactions between neighboring amino acid residues. As such, EMFs can affect the structure of protein molecules and change the properties of the bio-energy transported in living systems. This mechanism of biological effect from EMFs involves the amino acid residues in protein molecules. To study and reveal this mechanism, we simulated numerically the features of the movement of solitons along protein molecules with both a single chain and with three channels by using the Runge–Kutta method and Pang’s soliton model under the action of EMFs with the strengths of 25,500, 51,000, 76,500, and 102,000 V/m in the single-chain protein, as well as 17,000, 25,500, and 34,000 V/m in the three-chain protein, respectively. Results indicate that electric fields (EFs) depress the binding energy of the soliton, decrease its amplitude, and change its wave form. Also, the soliton disperses at 102,000 V/m in a single-chain protein and at 25,500 and 34,000 V/m in three-chain proteins. These findings signify that the influence of EMFs on the bio-energy transport cannot be neglected; however, these variations depend on both the strength and the direction of the EF in the EMF. This direction influences the biological effects of EMF, which decrease with increases in the angle between the direction of the EF and that of the dipole moment of amino acid residues; however, randomness at the macroscopic level remains. Lastly, we experimentally confirm the existence of a soliton and the validity of our conclusion by using the infrared spectra of absorption of the collagens, which is activated by another type of EF. Thus, we can affirm that both the described mechanism and the corresponding theory

Experimental and numerical measurements of adhesion energies between PHEMA and PGLYMA with hydroxyapatite crystal.

PubMed

Youssefian, Sina; Liu, Pingsheng; Askarinejad, Sina; Shalchy, Faezeh; Song, Jie; Rahbar, Nima

2015-07-16

Synthetic orthopaedic materials consisting of a single bioinert polymeric material do not meet the complex biological and physical requirements of scaffold-guided bone tissue repair and regeneration. Of particular interest is the design of biocompatible hydrogel-hydroxyapatite composite bone substitutes with outstanding interfacial adhesion that would warranty the ability for the composite to withstand functional loadings without exhibiting brittle fractures during the dynamic guided tissue regeneration. For this purpose, the hydroxylated side chain of chemically cross-linked poly (2-hydroxyethyl methacrylate) (pHEMA) is substitute with a carboxylated side chain to make poly (glycerol methacrylate) (pGLYMA). Here, we carry out atomistic simulations and atomic force microscopy to predict and experimentally determine the interfacial adhesion energies of pHEMA and pGLYMA with the surface of single-crystalline hydroxyapatite (HA) whiskers. Both experimental and numerical results showed that pGLYMA has stronger adhesion forces with HA and may be used for preparing a high-affinity polymer-HA composite. The high adhesive interactions between pGLYMA and HA were found to be due to strong electrostatic energies.

Theoretical and Experimental Evidence for a Nodal Energy Gap in MgB2

DTIC Science & Technology

2017-02-17

1   Theoretical and Experimental Evidence for a Nodal Energy Gap in MgB2 Y. Dan Agassia and Daniel E. Oatesb aConsultant, Jerusalem, Israel bMIT...surface impedance and intermodulation distortion in high-quality thin films. We briefly review experimental evidence in support of our hypothesis and...demonstrates, this experimental evidence agrees with the l = 6 hypothesis, while inconsistent with s-wave symmetry. To give the l = 6 hypothesis a

Experimental model of a wind energy conversion system

NASA Astrophysics Data System (ADS)

Vasar, C.; Rat, C. L.; Prostean, O.

2018-01-01

The renewable energy domain represents an important issue for the sustainable development of the mankind in the actual context of increasing demand for energy along with the increasing pollution that affect the environment. A significant quota of the clean energy is represented by the wind energy. As a consequence, the developing of wind energy conversion systems (WECS) in order to achieve high energetic performances (efficiency, stability, availability, competitive cost etc) represents a topic of permanent actuality. Testing and developing of an optimized control strategy for a WECS direct implemented on a real energetic site is quite difficult and not cost efficient. Thus a more convenient solution consists in a flexible laboratory setup which requires an experimental model of a WECS. Such approach would allow the simulation of various real conditions very similar with existing energetic sites. This paper presents a grid-connected wind turbine emulator. The wind turbine is implemented through a real-time Hardware-in-the-Loop (HIL) emulator, which will be analyzed extensively in the paper. The HIL system uses software implemented in the LabVIEW programming environment to control an ABB ACS800 electric drive. ACS800 has the task of driving an induction machine coupled to a permanent magnet synchronous generator. The power obtained from the synchronous generator is rectified, filtered and sent to the main grid through a controlled inverter. The control strategy is implemented on a NI CompactRIO (cRIO) platform.

Theoretical and experimental characterization of novel water-equivalent plastics in clinical high-energy carbon-ion beams.

PubMed

Lourenço, A; Wellock, N; Thomas, R; Homer, M; Bouchard, H; Kanai, T; MacDougall, N; Royle, G; Palmans, H

2016-11-07

Water-equivalent plastics are frequently used in dosimetry for experimental simplicity. This work evaluates the water-equivalence of novel water-equivalent plastics specifically designed for light-ion beams, as well as commercially available plastics in a clinical high-energy carbon-ion beam. A plastic- to-water conversion factor [Formula: see text] was established to derive absorbed dose to water in a water phantom from ionization chamber readings performed in a plastic phantom. Three trial plastic materials with varying atomic compositions were produced and experimentally characterized in a high-energy carbon-ion beam. Measurements were performed with a Roos ionization chamber, using a broad un-modulated beam of 11  ×  11 cm 2 , to measure the plastic-to-water conversion factor for the novel materials. The experimental results were compared with Monte Carlo simulations. Commercially available plastics were also simulated for comparison with the plastics tested experimentally, with particular attention to the influence of nuclear interaction cross sections. The measured [Formula: see text] correction increased gradually from 0% at the surface to 0.7% at a depth near the Bragg peak for one of the plastics prepared in this work, while for the other two plastics a maximum correction of 0.8%-1.3% was found. Average differences between experimental and numerical simulations were 0.2%. Monte Carlo results showed that for polyethylene, polystyrene, Rando phantom soft tissue and A-150, the correction increased from 0% to 2.5%-4.0% with depth, while for PMMA it increased to 2%. Water-equivalent plastics such as, Plastic Water, RMI-457, Gammex 457-CTG, WT1 and Virtual Water, gave similar results where maximum corrections were of the order of 2%. Considering the results from Monte Carlo simulations, one of the novel plastics was found to be superior in comparison with the plastic materials currently used in dosimetry, demonstrating that it is feasible to tailor

Theoretical and experimental characterization of novel water-equivalent plastics in clinical high-energy carbon-ion beams

NASA Astrophysics Data System (ADS)

Lourenço, A.; Wellock, N.; Thomas, R.; Homer, M.; Bouchard, H.; Kanai, T.; MacDougall, N.; Royle, G.; Palmans, H.

2016-11-01

Water-equivalent plastics are frequently used in dosimetry for experimental simplicity. This work evaluates the water-equivalence of novel water-equivalent plastics specifically designed for light-ion beams, as well as commercially available plastics in a clinical high-energy carbon-ion beam. A plastic- to-water conversion factor {{H}\\text{pl,w}} was established to derive absorbed dose to water in a water phantom from ionization chamber readings performed in a plastic phantom. Three trial plastic materials with varying atomic compositions were produced and experimentally characterized in a high-energy carbon-ion beam. Measurements were performed with a Roos ionization chamber, using a broad un-modulated beam of 11  ×  11 cm2, to measure the plastic-to-water conversion factor for the novel materials. The experimental results were compared with Monte Carlo simulations. Commercially available plastics were also simulated for comparison with the plastics tested experimentally, with particular attention to the influence of nuclear interaction cross sections. The measured H\\text{pl,w}\\exp correction increased gradually from 0% at the surface to 0.7% at a depth near the Bragg peak for one of the plastics prepared in this work, while for the other two plastics a maximum correction of 0.8%-1.3% was found. Average differences between experimental and numerical simulations were 0.2%. Monte Carlo results showed that for polyethylene, polystyrene, Rando phantom soft tissue and A-150, the correction increased from 0% to 2.5%-4.0% with depth, while for PMMA it increased to 2%. Water-equivalent plastics such as, Plastic Water, RMI-457, Gammex 457-CTG, WT1 and Virtual Water, gave similar results where maximum corrections were of the order of 2%. Considering the results from Monte Carlo simulations, one of the novel plastics was found to be superior in comparison with the plastic materials currently used in dosimetry, demonstrating that it is feasible to tailor plastic

Experimental Demonstration of Frequency Regulation by Commercial Buildings – Part II: Results and Performance Evaluation

DOE PAGES

Vrettos, Evangelos; Kara, Emre Can; MacDonald, Jason; ...

2016-11-15

This paper is the second part of a two-part series presenting the results from an experimental demonstration of frequency regulation in a commercial building test facility. We developed relevant building models and designed a hierarchical controller for reserve scheduling, building climate control and frequency regulation in Part I. In Part II, we introduce the communication architecture and experiment settings, and present extensive experimental results under frequency regulation. More specifically, we compute the day-ahead reserve capacity of the test facility under different assumptions and conditions. Furthermore, we demonstrate the ability of model predictive control to satisfy comfort constraints under frequency regulation,more » and show that fan speed control can track the fast-moving RegD signal of the Pennsylvania, Jersey, and Maryland Power Market (PJM) very accurately. In addition, we discuss potential effects of frequency regulation on building operation (e.g., increase in energy consumption, oscillations in supply air temperature, and effect on chiller cycling), and provide suggestions for real-world implementation projects. Our results show that hierarchical control is appropriate for frequency regulation from commercial buildings.« less

Experimental investigation on the energy deposition and morphology of the electrical explosion of copper wire in vacuum

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

Shi, Zongqian; Shi, Yuanjie; Wang, Kun

2016-03-15

This paper presents the experimental results of the electrical explosion of copper wires in vacuum using negative nanosecond-pulsed current with magnitude of 1–2 kA. The 20 μm-diameter copper wires with different lengths are exploded with three different current rates. A laser probe is applied to construct the shadowgraphy and interferometry diagnostics to investigate the distribution and morphology of the exploding product. The interference phase shift is reconstructed from the interferogram, by which the atomic density distribution is calculated. Experimental results show that there exist two voltage breakdown modes depending on the amount of the specific energy deposition. For the strong-shunting mode, shuntingmore » breakdown occurs, leading to the short-circuit-like current waveform. For the weak-shunting mode with less specific energy deposition, the plasma generated during the voltage breakdown is not enough to form a conductive plasma channel, resulting in overdamped declining current waveform. The influence of the wire length and current rate on the characteristics of the exploding wires is also analyzed.« less

Experimental investigation on the energy deposition and expansion rate under the electrical explosion of aluminum wire in vacuum

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

Shi, Zongqian; Wang, Kun; Shi, Yuanjie

Experimental investigations on the electrical explosion of aluminum wire using negative polarity current in vacuum are presented. Current pulses with rise rates of 40 A/ns, 80 A/ns, and 120 A/ns are generated for investigating the influence of current rise rate on energy deposition. Experimental results show a significant increase of energy deposition into the wire before the voltage breakdown with the increase of current rise rate. The influence of wire dimension on energy deposition is investigated as well. Decreasing the wire length allows more energy to be deposited into the wire. The energy deposition of a 0.5 cm-long wire explosion ismore » ∼2.5 times higher than the energy deposition of a 2 cm-long wire explosion. The dependence of the energy deposition on wire diameter demonstrates a maximum energy deposition of 2.7 eV/atom with a diameter of ∼18 μm. Substantial increase in energy deposition is observed in the electrical explosion of aluminum wire with polyimide coating. A laser probe is applied to construct the shadowgraphy, schlieren, and interferometry diagnostics. The morphology and expansion trajectory of exploding products are analyzed based on the shadowgram. The interference phase shift is reconstructed from the interferogram. Parallel dual wires are exploded to estimate the expansion velocity of the plasma shell.« less

Molecular interactions between photosystem I and ferredoxin: an integrated energy frustration and experimental model

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

Cashman, Derek J.; Zhu, Tuo; Simmerman, Richard F.

2014-08-01

The stromal domain (PsaC, PsaD, and PsaE) of photosystem I (PSI) reduces transiently bound ferredoxin (Fd) or flavodoxin. Experimental structures exist for all of these protein partners individually, but no experimental structure of the PSI/Fd or PSI/flavodoxin complexes is presently available. Molecular models of Fd docked onto the stromal domain of the cyanobacterial PSI site are constructed here utilizing X-ray and NMR structures of PSI and Fd, respectively. Moreover, predictions of potential protein-protein interaction regions are based on experimental site-directed mutagenesis and cross-linking studies to guide rigid body docking calculations of Fd into PSI, complemented by energy landscape theory tomore » bring together regions of high energetic frustration on each of the interacting proteins. Results identify two regions of high localized frustration on the surface of Fd that contain negatively charged Asp and Glu residues. Our study predicts that these regions interact predominantly with regions of high localized frustration on the PsaC, PsaD, and PsaE chains of PSI, which include several residues predicted by previous experimental studies.« less

Modeling and experimental result analysis for high-power VECSELs

NASA Astrophysics Data System (ADS)

Zakharian, Aramais R.; Hader, Joerg; Moloney, Jerome V.; Koch, Stephan W.; Lutgen, Stephan; Brick, Peter; Albrecht, Tony; Grotsch, Stefan; Luft, Johann; Spath, Werner

2003-06-01

We present a comparison of experimental and microscopically based model results for optically pumped vertical external cavity surface emitting semiconductor lasers. The quantum well gain model is based on a quantitative ab-initio approach that allows calculation of a complex material susceptibility dependence on the wavelength, carrier density and lattice temperature. The gain model is coupled to the macroscopic thermal transport, spatially resolved in both the radial and longitudinal directions, with temperature and carrier density dependent pump absorption. The radial distribution of the refractive index and gain due to temperature variation are computed. Thermal managment issues, highlighted by the experimental data, are discussed. Experimental results indicate a critical dependence of the input power, at which thermal roll-over occurs, on the thermal resistance of the device. This requires minimization of the substrate thickness and optimization of the design and placement of the heatsink. Dependence of the model results on the radiative and non-radiative carrier recombination lifetimes and cavity losses are evaluated.

Results of design studies and wind tunnel tests of an advanced high lift system for an Energy Efficient Transport

NASA Technical Reports Server (NTRS)

Oliver, W. R.

1980-01-01

The development of an advanced technology high lift system for an energy efficient transport incorporating a high aspect ratio supercritical wing is described. This development is based on the results of trade studies to select the high lift system, analysis techniques utilized to design the high lift system, and results of a wind tunnel test program. The program included the first experimental low speed, high Reynolds number wind tunnel test for this class of aircraft. The experimental results include the effects on low speed aerodynamic characteristics of various leading and trailing edge devices, nacelles and pylons, aileron, spoilers, and Mach and Reynolds numbers. Results are discussed and compared with the experimental data and the various aerodynamic characteristics are estimated.

Experimental estimation of energy absorption during heel strike in human barefoot walking.

PubMed

Baines, Patricia M; Schwab, A L; van Soest, A J

2018-01-01

Metabolic energy expenditure during human gait is poorly understood. Mechanical energy loss during heel strike contributes to this energy expenditure. Previous work has estimated the energy absorption during heel strike as 0.8 J using an effective foot mass model. The aim of our study is to investigate the possibility of determining the energy absorption by more directly estimating the work done by the ground reaction force, the force-integral method. Concurrently another aim is to compare this method of direct determination of work to the method of an effective foot mass model. Participants of our experimental study were asked to walk barefoot at preferred speed. Ground reaction force and lower leg kinematics were collected at high sampling frequency (3000 Hz; 1295 Hz), with tight synchronization. The work done by the ground reaction force is 3.8 J, estimated by integrating this force over the foot-ankle deformation. The effective mass model is improved by dropping the assumption that foot-ankle deformation is maximal at the instant of the impact force peak. On theoretical grounds it is clear that in the presence of substantial damping that peak force and peak deformation do not occur simultaneously. The energy absorption results, due the vertical force only, corresponding to the force-integral method is similar to the results of the improved application of the effective mass model (2.7 J; 2.5 J). However the total work done by the ground reaction force calculated by the force-integral method is significantly higher than that of the vertical component alone. We conclude that direct estimation of the work done by the ground reaction force is possible and preferable over the use of the effective foot mass model. Assuming that energy absorbed is lost, the mechanical energy loss of heel strike is around 3.8 J for preferred walking speeds (≈ 1.3 m/s), which contributes to about 15-20% of the overall metabolic cost of transport.

Experimental results for correlation-based wavefront sensing

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

Poyneer, L A; Palmer, D W; LaFortune, K N

2005-07-01

Correlation wave-front sensing can improve Adaptive Optics (AO) system performance in two keys areas. For point-source-based AO systems, Correlation is more accurate, more robust to changing conditions and provides lower noise than a centroiding algorithm. Experimental results from the Lick AO system and the SSHCL laser AO system confirm this. For remote imaging, Correlation enables the use of extended objects for wave-front sensing. Results from short horizontal-path experiments will show algorithm properties and requirements.

Cold Climate Foundation Retrofit Experimental Hygrothermal Performance. Cloquet Residential Research Facility Laboratory Results

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

Goldberg, Louise F.; Harmon, Anna C.

2015-04-09

This project was funded jointly by the National Renewable Energy Laboratory (NREL) and Oak Ridge National Laboratory (ORNL). ORNL focused on developing a full basement wall system experimental database to enable others to validate hygrothermal simulation codes. NREL focused on testing the moisture durability of practical basement wall interior insulation retrofit solutions for cold climates. The project has produced a physically credible and reliable long-term hygrothermal performance database for retrofit foundation wall insulation systems in zone 6 and 7 climates that are fully compliant with the performance criteria in the 2009 Minnesota Energy Code. These data currently span the periodmore » from November 10, 2012 through May 31, 2014 and are anticipated to be extended through November 2014. The experimental data were configured into a standard format that can be published online and that is compatible with standard commercially available spreadsheet and database software.« less

Distributions of experimental protein structures on coarse-grained free energy landscapes

PubMed Central

Liu, Jie; Jernigan, Robert L.

2015-01-01

Predicting conformational changes of proteins is needed in order to fully comprehend functional mechanisms. With the large number of available structures in sets of related proteins, it is now possible to directly visualize the clusters of conformations and their conformational transitions through the use of principal component analysis. The most striking observation about the distributions of the structures along the principal components is their highly non-uniform distributions. In this work, we use principal component analysis of experimental structures of 50 diverse proteins to extract the most important directions of their motions, sample structures along these directions, and estimate their free energy landscapes by combining knowledge-based potentials and entropy computed from elastic network models. When these resulting motions are visualized upon their coarse-grained free energy landscapes, the basis for conformational pathways becomes readily apparent. Using three well-studied proteins, T4 lysozyme, serum albumin, and sarco-endoplasmic reticular Ca2+ adenosine triphosphatase (SERCA), as examples, we show that such free energy landscapes of conformational changes provide meaningful insights into the functional dynamics and suggest transition pathways between different conformational states. As a further example, we also show that Monte Carlo simulations on the coarse-grained landscape of HIV-1 protease can directly yield pathways for force-driven conformational changes. PMID:26723638

Experimental evidence of the decrease of kinetic energy of hadrons in passing through atomic nuclei

NASA Technical Reports Server (NTRS)

Strugalski, Z.

1985-01-01

Hadrons with kinetic energies higher than the pion production threshold lose their kinetic energies monotonically in traversing atomic nuclei, due to the strong interactions in nuclear matter. This phenomenon is a crude analogy to the energy loss of charged particles in their passage through materials. Experimental evidence is presented.

Theoretical and experimental evidence for a nodal energy gap in MgB2

NASA Astrophysics Data System (ADS)

Agassi, Y. Dan; Oates, Daniel E.

2017-11-01

We present a phenomenological model that strongly suggests that the smaller of the two energy gaps in MgB2, the so-called π gap, contains nodal lines with a six-fold symmetry (i-wave). The model also indicates that the larger gap, the so-called σ gap, is conventional s-wave. The model is an extension of the BCS gap equation that accounts for the elastic anisotropy in MgB2 and the Coulomb repulsion. It is based on a phononic pairing mechanism and assumes no coupling between the two energy gaps in MgB2 at zero temperature. All of the parameters of the model, such as sound velocities and masses, are independently determined material constants. The results agree with a previous ad-hoc hypothesis that the π energy gap has six nodal lines. That hypothesis was motivated by low-temperature measurements of the surface impedance and intermodulation distortion in high-quality thin films. We briefly review experimental evidence in the literature that is relevant to the energy-gap symmetry. We find that the evidence from the literature for s-wave is inconclusive. Our finding is that the π gap has six nodal lines.

Numerical Simulation and Experimental Verification of Hollow and Foam-Filled Flax-Fabric-Reinforced Epoxy Tubular Energy Absorbers Subjected to Crashing

NASA Astrophysics Data System (ADS)

Sliseris, J.; Yan, L.; Kasal, B.

2017-09-01

Numerical methods for simulating hollow and foam-filled flax-fabric-reinforced epoxy tubular energy absorbers subjected to lateral crashing are presented. The crashing characteristics, such as the progressive failure, load-displacement response, absorbed energy, peak load, and failure modes, of the tubes were simulated and calculated numerically. A 3D nonlinear finite-element model that allows for the plasticity of materials using an isotropic hardening model with strain rate dependence and failure is proposed. An explicit finite-element solver is used to address the lateral crashing of the tubes considering large displacements and strains, plasticity, and damage. The experimental nonlinear crashing load vs. displacement data are successfully described by using the finite-element model proposed. The simulated peak loads and absorbed energy of the tubes are also in good agreement with experimental results.

An experimental-finite element analysis on the kinetic energy absorption capacity of polyvinyl alcohol sponge.

PubMed

Karimi, Alireza; Navidbakhsh, Mahdi; Razaghi, Reza

2014-06-01

Polyvinyl alcohol (PVA) sponge is in widespread use for biomedical and tissue engineering applications owing to its biocompatibility, availability, relative cheapness, and excellent mechanical properties. This study reports a novel concept of design in energy absorbing materials which consist in the use of PVA sponge as an alternative reinforcement material to enhance the energy loss of impact loads. An experimental study is carried out to measure the mechanical properties of the PVA sponge under uniaxial loading. The kinetic energy absorption capacity of the PVA sponge is computed by a hexahedral finite element (FE) model of the steel ball and bullet through the LS-DYNA code under impact load at three different thicknesses (5, 10, 15mm). The results show that a higher sponge thickness invokes a higher energy loss of the steel ball and bullet. The highest energy loss of the steel ball and bullet is observed for the thickest sponge with 160 and 35J, respectively. The most common type of traumatic brain injury in which the head subject to impact load causes the brain to move within the skull and consequently brain hemorrhaging. These results suggest the application of the PVA sponge as a great kinetic energy absorber material compared to commonly used expanded polystyrene foams (EPS) to absorb most of the impact energy and reduces the transmitted load. The results might have implications not only for understanding of the mechanical properties of PVA sponge but also for use as an alternative reinforcement material in helmet and packaging material design. Copyright © 2014 Elsevier B.V. All rights reserved.

Methods of experimentation with models and utilization of results

NASA Technical Reports Server (NTRS)

Robert,

1924-01-01

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.

Multi-Level Experimental and Analytical Evaluation of Two Composite Energy Absorbers

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Littell, Justin D.; Fasanella, Edwin L.; Annett, Martin S.; Seal, Michael D., II

2015-01-01

Two composite energy absorbers were developed and evaluated at NASA Langley Research Center through multi-level testing and simulation performed under the Transport Rotorcraft Airframe Crash Testbed (TRACT) research program. A conical-shaped energy absorber, designated the conusoid, was evaluated that consisted of four layers of hybrid carbon-Kevlar plain weave fabric oriented at [+45 deg/-45 deg/-45 deg/+45 deg] with respect to the vertical, or crush, direction. A sinusoidal-shaped energy absorber, designated the sinusoid, was developed that consisted of hybrid carbon-Kevlar plain weave fabric face sheets, two layers for each face sheet oriented at +/-45deg with respect to the vertical direction and a closed-cell ELFOAM P200 polyisocyanurate (2.0-lb/cu ft) foam core. The design goal for the energy absorbers was to achieve average floor-level accelerations of between 25- and 40-g during the full-scale crash test of a retrofitted CH-46E helicopter airframe, designated TRACT 2. Variations in both designs were assessed through dynamic crush testing of component specimens. Once the designs were finalized, subfloor beams of each configuration were fabricated and retrofitted into a barrel section of a CH-46E helicopter. A vertical drop test of the barrel section was conducted onto concrete to evaluate the performance of the energy absorbers prior to retrofit into TRACT 2. The retrofitted airframe was crash tested under combined forward and vertical velocity conditions onto soil, which is characterized as a sand/clay mixture. Finite element models were developed of all test articles and simulations were performed using LS-DYNA, a commercial nonlinear explicit transient dynamic finite element code. Test-analysis results are presented for each energy absorber as comparisons of time-history responses, as well as predicted and experimental structural deformations and progressive damage under impact loading for each evaluation level.

VX Hydrolysis by Human Serum Paraoxonase 1: A Comparison of Experimental and Computational Results

PubMed Central

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

2011-01-01

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 (VXts) 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-VXts 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 VXts 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

Hydrocarbon-Fueled Rocket Engine Plume Diagnostics: Analytical Developments and Experimental Results

NASA Technical Reports Server (NTRS)

Tejwani, Gopal D.; McVay, Gregory P.; Langford, Lester A.; St. Cyr, William W.

2006-01-01

A viewgraph presentation describing experimental results and analytical developments about plume diagnostics for hydrocarbon-fueled rocket engines is shown. The topics include: 1) SSC Plume Diagnostics Background; 2) Engine Health Monitoring Approach; 3) Rocket Plume Spectroscopy Simulation Code; 4) Spectral Simulation for 10 Atomic Species and for 11 Diatomic Molecular Electronic Bands; 5) "Best" Lines for Plume Diagnostics for Hydrocarbon-Fueled Rocket Engines; 6) Experimental Set Up for the Methane Thruster Test Program and Experimental Results; and 7) Summary and Recommendations.

Investigating energy-based pool structure selection in the structure ensemble modeling with experimental distance constraints: The example from a multidomain protein Pub1.

PubMed

Zhu, Guanhua; Liu, Wei; Bao, Chenglong; Tong, Dudu; Ji, Hui; Shen, Zuowei; Yang, Daiwen; Lu, Lanyuan

2018-05-01

The structural variations of multidomain proteins with flexible parts mediate many biological processes, and a structure ensemble can be determined by selecting a weighted combination of representative structures from a simulated structure pool, producing the best fit to experimental constraints such as interatomic distance. In this study, a hybrid structure-based and physics-based atomistic force field with an efficient sampling strategy is adopted to simulate a model di-domain protein against experimental paramagnetic relaxation enhancement (PRE) data that correspond to distance constraints. The molecular dynamics simulations produce a wide range of conformations depicted on a protein energy landscape. Subsequently, a conformational ensemble recovered with low-energy structures and the minimum-size restraint is identified in good agreement with experimental PRE rates, and the result is also supported by chemical shift perturbations and small-angle X-ray scattering data. It is illustrated that the regularizations of energy and ensemble-size prevent an arbitrary interpretation of protein conformations. Moreover, energy is found to serve as a critical control to refine the structure pool and prevent data overfitting, because the absence of energy regularization exposes ensemble construction to the noise from high-energy structures and causes a more ambiguous representation of protein conformations. Finally, we perform structure-ensemble optimizations with a topology-based structure pool, to enhance the understanding on the ensemble results from different sources of pool candidates. © 2018 Wiley Periodicals, Inc.

An experimental study of OH(A2Σ+) + H2: Electronic quenching, rotational energy transfer, and collisional depolarization

NASA Astrophysics Data System (ADS)

Brouard, M.; Lawlor, J.; McCrudden, G.; Perkins, T.; Seamons, S. A.; Stevenson, P.; Chadwick, H.; Aoiz, F. J.

2017-06-01

Zeeman quantum beat spectroscopy has been used to determine the thermal (300 K) rate constants for electronic quenching, rotational energy transfer, and collisional depolarization of OH(A2Σ+) by H2. Cross sections for both the collisional disorientation and collisional disalignment of the angular momentum in the OH(A2Σ+) radical are reported. The experimental results for OH(A2Σ+) + H2 are compared to previous work on the OH(A2Σ+) + He and Ar systems. Further comparisons are also made to the OH(A2Σ+) + Kr system, which has been shown to display significant non-adiabatic dynamics. The OH(A2Σ+) + H2 experimental data reveal that collisions that survive the electronic quenching process are highly depolarizing, reflecting the deep potential energy wells that exist on the excited electronic state surface.

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

PubMed

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

2011-01-01

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.

AN EXPERIMENTAL STUDY OF THE DIRECT PRODUCTION OF PI MESONS BY HIGH-ENERGY ELECTRONS

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

Hand, L.N.

1962-04-01

The direct production of pi mesons by high-energy electrons was studied experimentally as an indirect measurement of the charge and magnetic structure of the neutron. The reactions of interest are: e/sup -/ + p/sup +/ yields e/sup -/ + p/sup ~+/ + i/sup 0/ and e/sup -/ + p/sup +/ yields e/sup -/ + n/sup 0/ + pi /sup +/. Only the final electro n is observed. Physically the experiment consists of passing a beam of electrons through a liquid hydrogen target. Electrons scattered at a given angle and having momenta within a certain range about a selected value aremore » analyzed with a magnetic spectrometer and counted by virtue of their Cerenkov light in a counter filled with paraffin oil. This counter has been designed to minimize the background. Counting rates for positive and negative particles are recorded for each momentum setting. The initial and final energies may be programmed to vary either the pionnucleon dynamics or the invariant four-momentum transfer (q/sup 2/) independently. The behavior of the cross section as a function of the latter variable is in part determined by charge and magnetic moment distributions of the proton and neutron and by the charge distribution of the pion. It is unfortunate that the sensitivity of the present experiment to the pion size is rather low, as no published information exists on this quantity. One important difference between electroproduction and the more usual gamma-ray excitation of mesons is the possibility of inducing the above reactions with the electric field possessed by the electron along its direction of motion. A simple proof was found of a theorem which permits a purely experimental determination of the amount of this longitudinal interaction relative to the transverse interaction occurring in both the electron and gamma-ray production of pions. This theorem is applicable to a wide class of electron scattering experiments. The results indicate the absence of any longitudinal pion production in the energy

Experimental observation of electron bounce resonance through electron energy distribution measurement in a finite size inductively coupled plasma

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

Gu, Seuli; Kang, Hyun-Ju; Kim, Yu-Sin

2016-06-15

The electron bounce resonance was experimentally investigated in a low pressure planar inductively coupled plasma. The electron energy probability functions (EEPFs) were measured at different chamber heights and the energy diffusion coefficients were calculated by the kinetic model. It is found that the EEPFs begin to flatten at the first electron bounce resonance condition, and the plateau shifts to a higher electron energy as the chamber height increases. The plateau which indicates strong electron heating corresponds not only to the electron bounce resonance condition but also to the peaks of the first component of the energy diffusion coefficients. As amore » result, the plateau formation in the EEPFs is mainly due to the electron bounce resonance in a finite inductive discharge.« less

Experimental analysis of energy absorption behaviour of Al-tube filled with pumice lightweight concrete under axial loading condition

NASA Astrophysics Data System (ADS)

Rajak, D. K.; Deshpande, P. G.; Kumaraswamidhas, L. A.

2017-08-01

This Paper aimed at experimental investigation of compressive behaviour of square tube filled with pumice lightweight concrete (PLC). Square section of 20×20×30 mm is investigated, which is the backbone structure. The compression deformation result shows the better folding mechanism, displacement value, and energy absorption. PLC concrete filled with aluminium thin-wall tubes has been revealed superior energy absorption capacity (EAC) under low strain rate at room temperature. Superior EAC resulted as a result of mutual deformation benefit between aluminium section and PLC is also analysed. PLC was characterised by Fourier Transform Infrared (FTIR) and Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive X-ray Spectrometry (EDX) analysis for better understanding of material behaviour. Individual and comparative load bearing graphs is logged for better prospective of analysing. Novel approach aimed at validation of porous lightweight concrete for better lightweight EA filler material.

DoSSiER: Database of scientific simulation and experimental results

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

Wenzel, Hans; Yarba, Julia; Genser, Krzystof

The Geant4, GeantV and GENIE collaborations regularly perform validation and regression tests for simulation results. DoSSiER (Database of Scientific Simulation and Experimental Results) is being developed as a central repository to store the simulation results as well as the experimental data used for validation. DoSSiER can be easily accessed via a web application. In addition, a web service allows for programmatic access to the repository to extract records in json or xml exchange formats. In this paper, we describe the functionality and the current status of various components of DoSSiER as well as the technology choices we made.

DoSSiER: Database of scientific simulation and experimental results

DOE PAGES

Wenzel, Hans; Yarba, Julia; Genser, Krzystof; ...

2016-08-01

The Geant4, GeantV and GENIE collaborations regularly perform validation and regression tests for simulation results. DoSSiER (Database of Scientific Simulation and Experimental Results) is being developed as a central repository to store the simulation results as well as the experimental data used for validation. DoSSiER can be easily accessed via a web application. In addition, a web service allows for programmatic access to the repository to extract records in json or xml exchange formats. In this paper, we describe the functionality and the current status of various components of DoSSiER as well as the technology choices we made.

Experimental studies of 7-cell dual axis asymmetric cavity for energy recovery linac

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

Konoplev, Ivan V.; Metodiev, K.; Lancaster, A. J.

High average current, transportable energy recovery linacs (ERLs) can be very attractive tools for a number of applications including next generation high-luminosity, compact light sources. Conventional ERLs are based on an electron beam circulating through the same set of rf cavity cells. This leads to an accumulation of high-order modes inside the cavity cells, resulting in the development of a beam breakup (BBU) instability, unless the beam current is kept below the BBU start current. This limits the maximum current which can be transported through the ERL and hence the intensity of the photon beam generated. It has recently beenmore » proposed that splitting the accelerating and decelerating stages, tuning them separately and coupling them via a resonance coupler can increase the BBU start current. The paper presents the first experimental rf studies of a dual axis 7-cell asymmetric cavity and confirms the properties predicted by the theoretical model. The field structures of the symmetric and asymmetric modes are measured and good agreement with the numerical predictions is demonstrated. The operating mode field flatness was also measured and discussed. A novel approach based on the coupled mode (Fano-like) model has been developed for the description of the cavity eigenmode spectrum and good agreement between analytical theory, numerical predictions and experimental data is shown. Finally, numerical and experimental results observed are analyzed, discussed and a good agreement between theory and experiment is demonstrated.« less

Experimental studies of 7-cell dual axis asymmetric cavity for energy recovery linac

DOE PAGES

Konoplev, Ivan V.; Metodiev, K.; Lancaster, A. J.; ...

2017-10-10

High average current, transportable energy recovery linacs (ERLs) can be very attractive tools for a number of applications including next generation high-luminosity, compact light sources. Conventional ERLs are based on an electron beam circulating through the same set of rf cavity cells. This leads to an accumulation of high-order modes inside the cavity cells, resulting in the development of a beam breakup (BBU) instability, unless the beam current is kept below the BBU start current. This limits the maximum current which can be transported through the ERL and hence the intensity of the photon beam generated. It has recently beenmore » proposed that splitting the accelerating and decelerating stages, tuning them separately and coupling them via a resonance coupler can increase the BBU start current. The paper presents the first experimental rf studies of a dual axis 7-cell asymmetric cavity and confirms the properties predicted by the theoretical model. The field structures of the symmetric and asymmetric modes are measured and good agreement with the numerical predictions is demonstrated. The operating mode field flatness was also measured and discussed. A novel approach based on the coupled mode (Fano-like) model has been developed for the description of the cavity eigenmode spectrum and good agreement between analytical theory, numerical predictions and experimental data is shown. Finally, numerical and experimental results observed are analyzed, discussed and a good agreement between theory and experiment is demonstrated.« less

An experimental study of energy dependence of saturation thickness of multiply scattered gamma rays in binary alloys

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

Singh, Gurvinderjit; Singh, Bhajan, E-mail: bhajan2k1@yahoo.co.in; Sandhu, B. S.

2015-08-28

The present measurements are carried out to investigate the multiple scattering of 662 keV gamma photons emerging from targets of binary alloys (brass and soldering material). The scattered photons are detected by 51 mm × 51 mm NaI(Tl) scintillation detector whose response unscrambling converting the observed pulse–height distribution to a true photon energy spectrum, is obtained with the help of 10 × 10 inverse response matrix. The numbers of multiply scattered events, having same energy as in the singly scattered distribution, first increases with target thickness and then saturate. The application of response function of scintillation detector does not result in anymore » change of measured saturation thickness. Monte Carlo calculation supports the present experimental results.« less

Error-based Extraction of States and Energy Landscapes from Experimental Single-Molecule Time-Series

NASA Astrophysics Data System (ADS)

Taylor, J. Nicholas; Li, Chun-Biu; Cooper, David R.; Landes, Christy F.; Komatsuzaki, Tamiki

2015-03-01

Characterization of states, the essential components of the underlying energy landscapes, is one of the most intriguing subjects in single-molecule (SM) experiments due to the existence of noise inherent to the measurements. Here we present a method to extract the underlying state sequences from experimental SM time-series. Taking into account empirical error and the finite sampling of the time-series, the method extracts a steady-state network which provides an approximation of the underlying effective free energy landscape. The core of the method is the application of rate-distortion theory from information theory, allowing the individual data points to be assigned to multiple states simultaneously. We demonstrate the method's proficiency in its application to simulated trajectories as well as to experimental SM fluorescence resonance energy transfer (FRET) trajectories obtained from isolated agonist binding domains of the AMPA receptor, an ionotropic glutamate receptor that is prevalent in the central nervous system.

Contact angle and surface free energy of experimental resin-based dental restorative materials after chewing simulation.

PubMed

Rüttermann, Stefan; Beikler, Thomas; Janda, Ralf

2014-06-01

To investigate contact angle and surface free energy of experimental dental resin composites containing novel delivery systems of polymeric hollow beads and low-surface tension agents after chewing simulation test. A delivery system of novel polymeric hollow beads differently loaded with two low-surface tension agents was used in different amounts to modify commonly formulated experimental dental resin composites. The non-modified resin was used as standard. Surface roughness Ra, contact angle Θ, total surface free energy γS, its apolar γS(LW), polar γS(AB), Lewis acid γS(+) and base γS(-) terms were determined and the results prior to and after chewing simulation test were compared. Significance was p<0.05. After chewing simulation Ra increased, Θ decreased, Ra increased for two test materials and γS decreased or remained constant for the standard or the test materials after chewing simulation. Ra of one test material was higher than of the standard, Θ and γS of the test materials remained lower than of the standard and, indicating their highly hydrophobic character (Θ≈60-75°, γS≈30mJm(-2)). γS(LW), and γS(-) of the test materials were lower than of the standard. Some of the test materials had lower γS(AB) and γS(+) than of the standard. Delivery systems based on novel polymeric hollow beads highly loaded with low-surface tension agents were found to significantly increase contact angle and thus to reduce surface free energy of experimental dental resin composites prior to and after chewing simulation test. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Experimental investigations of recent anomalous results in superconductivity

NASA Astrophysics Data System (ADS)

Souw, Victor K.

2000-12-01

This thesis examines three recent anomalous results associated with irreversibility in type-II superconductivity: (1) The magnetic properties of the predicted superconductors LiBeH3 and Li2BeH 4, (2) the paramagnetic transition near T = Tc in Nb, and (3) a noise transition in a YBa2Cu3O7-delta thin film near the vortex-solid transition. The investigation of Li 2BeH4 and LiBeH3 was prompted by theoretical predictions of room-temperature superconductivity for Li2BeH4 and LiBeH3 and a recent report that Li2BeH4 showed magnetic irreversibilities similar to those of type-II superconductors. A modified experimental method is introduced in order to avoid artifacts due to background signals. The resulting data is suggestive of a superparamagnetic impurity from one of the reagents used in the synthesis and after subtracting this contribution, the temperature-dependent susceptibilities of Li2 BeH4 and LiBeH3 are estimated. However, no magnetic irreversibility suggestive of superconductivity is observed. The anomalous paramagnetic transition in Nb is intriguing because Nb does not share the d-wave order parameter symmetry often invoked to explain the phenomenon in other superconductors. A modified experimental method was developed in order to avoid instrumental artifacts known to produce a similar apparently paramagnetic response, but the results of this method indicate that the paramagnetic response is a physical property of the sample. Finally, a very sharp noise transition in a YBa2Cu3O7-delta thin film was found to be distinct from previously reported features in the voltage noise commonly associated with vortex fluctuations near the irreversibility line. In each of these three cases the examination of experimental techniques is an integral part of the investigation of novel vortex behavior near the onset of irreversibility.

The Changing Energy Sources of Soil Respiration Seasonally and with Experimental Warming

NASA Astrophysics Data System (ADS)

Hicks Pries, C.; Angert, A.; Castanha, C.; Hilman, B.; Torn, M. S.

2017-12-01

Due to its importance in the global carbon cycle, soil respiration has been intensively measured. However, measurements are almost exclusively of CO2, which has limited our understanding of soil respiration's sources and its responses to climate change. Here, we show how dual CO2 and O2 measurements within the soil profile of a temperate forest can indicate how the energy sources driving soil respiration can change seasonally and with experimental warming. We calculated the apparent respiration quotient (ARQ), defined as CO2 produced/O2 consumed, calculated from gas soil concentrations and adjusted for differences in diffusion rates. The ARQ changes depending on the stoichiometry of the organic compounds utilized for energy by microbes and roots. Oxidation of carbohydrates and organic acids results in respiration quotients ≥1 while oxidation of lipids results in respiration quotients ≈0.7 with oxidation of proteins falling in between. We observed clear seasonal patterns in ARQ, with values ≈0.9 during the late spring and summer decreasing to 0.6-0.7 during the winter. These changes in ARQ imply carbohydrates are a more important energy source during the summer when trees are photosynthesizing and providing fresh substrate to both roots and microbes. During the winter, lipids, likely recycled within microbial biomass, are a more important energy source. Furthermore, winter ARQ was higher in heated plots (+4° relative to control) than in control plots, but only at 30 cm, possibly due to increased root activity with heating. These interpretations are supported by δ13CO2 values, which were relatively depleted in the winter and more enriched in the summer—lipids are more depleted in δ13C than are sugars. Consistent with the heating effect, there were strong correlations between temperature and ARQ and temperature and δ13C. Given the large differences in ARQ in this forest soil, we are looking into using ARQ to partition soil respiration fluxes based on

Search for the critical point of the nuclear matter phase diagram. first results from the beam energy SCAN program at RHIC

DOE PAGES

Odyniec, Grazyna

2012-01-01

In 2010, the Relativistic Heavy Ion Collider (RHIC) launched a multi-step experimental program to investigate the QCD Phase Diagram in general, and to search for the QCD Critical Point (CP) and/or 1st order phase transition in particular. The BES (Beam Energy Scan) program involves an “energy scan” of Au+Au collisions from the top RHIC energy (√s = 200 GeV) down to energies as low as 5 GeV in NN center of mass. During the first BES run (2010), data were collected at 7.7, 11.5 and 39 GeV. It was complemented in 2011 by two other data sets at 27 andmore » 19.6 GeV. The preparations for the remaining data taking at √s = 5 GeV are in progress. The overview of the BES program and the first experimental results are presented and discussed.« less

Search for the critical point of the nuclear matter phase diagram. first results from the beam energy SCAN program at RHIC

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

Odyniec, Grazyna

In 2010, the Relativistic Heavy Ion Collider (RHIC) launched a multi-step experimental program to investigate the QCD Phase Diagram in general, and to search for the QCD Critical Point (CP) and/or 1st order phase transition in particular. The BES (Beam Energy Scan) program involves an “energy scan” of Au+Au collisions from the top RHIC energy (√s = 200 GeV) down to energies as low as 5 GeV in NN center of mass. During the first BES run (2010), data were collected at 7.7, 11.5 and 39 GeV. It was complemented in 2011 by two other data sets at 27 andmore » 19.6 GeV. The preparations for the remaining data taking at √s = 5 GeV are in progress. The overview of the BES program and the first experimental results are presented and discussed.« less

Extension of the energy range of experimental activation cross-sections data of deuteron induced nuclear reactions on indium up to 50MeV.

PubMed

Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Ignatyuk, A V

2015-11-01

The energy range of our earlier measured activation cross-sections data of longer-lived products of deuteron induced nuclear reactions on indium were extended from 40MeV up to 50MeV. The traditional stacked foil irradiation technique and non-destructive gamma spectrometry were used. No experimental data were found in literature for this higher energy range. Experimental cross-sections for the formation of the radionuclides (113,110)Sn, (116m,115m,114m,113m,111,110g,109)In and (115)Cd are reported in the 37-50MeV energy range, for production of (110)Sn and (110g,109)In these are the first measurements ever. The experimental data were compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS 1.6 nuclear model code as listed in the on-line library TENDL-2014. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cold Climate Foundation Retrofit Experimental Hygrothermal Performance: Cloquet Residential Research Facility Laboratory Results

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

Goldberg, Louise F.; Harmon, Anna C.

2015-04-01

Thermal and moisture problems in existing basements create a unique challenge because the exterior face of the wall is not easily or inexpensively accessible. This approach addresses thermal and moisture management from the interior face of the wall without disturbing the exterior soil and landscaping. the interior and exterior environments. This approach has the potential for improving durability, comfort, and indoor air quality. This project was funded jointly by the National Renewable Energy Laboratory (NREL) and Oak Ridge National Laboratory (ORNL). ORNL focused on developing a full basement wall system experimental database to enable others to validate hygrothermal simulation codes.more » NREL focused on testing the moisture durability of practical basement wall interior insulation retrofit solutions for cold climates. The project has produced a physically credible and reliable long-term hygrothermal performance database for retrofit foundation wall insulation systems in zone 6 and 7 climates that are fully compliant with the performance criteria in the 2009 Minnesota Energy Code. The experimental data were configured into a standard format that can be published online and that is compatible with standard commercially available spreadsheet and database software.« less

Free Energy Landscape of Protein-Protein Encounter Resulting from Brownian Dynamics Simulations of Barnase:Barstar.

PubMed

Spaar, Alexander; Helms, Volkhard

2005-07-01

Over the past years Brownian dynamics (BD) simulations have been proven to be a suitable tool for the analysis of protein-protein association. The computed rates and relative trends for protein mutants and different ionic strength are generally in good agreement with experimental results, e.g. see ref 1. By design, BD simulations correspond to an intensive sampling over energetically favorable states, rather than to a systematic sampling over all possible states which is feasible only at rather low resolution. On the example of barnase and barstar, a well characterized model system of electrostatically steered diffusional encounter, we report here the computation of the 6-dimensional free energy landscape for the encounter process of two proteins by a novel, careful analysis of the trajectories from BD simulations. The aim of these studies was the clarification of the encounter state. Along the trajectories, the individual positions and orientations of one protein (relative to the other) are recorded and stored in so-called occupancy maps. Since the number of simulated trajectories is sufficiently high, these occupancy maps can be interpreted as a probability distribution which allows the calculation of the entropy landscape by the use of a locally defined entropy function. Additionally, the configuration dependent electrostatic and desolvation energies are recorded in separate maps. The free energy landscape of protein-protein encounter is finally obtained by summing the energy and entropy contributions. In the free energy profile along the reaction path, which is defined as the path along the minima in the free energy landscape, a minimum shows up suggesting this to be used as the definition of the encounter state. This minimum describes a state of reduced diffusion velocity where the electrostatic attraction is compensated by the repulsion due to the unfavorable desolvation of the charged residues and the entropy loss due to the increasing restriction of the

Clinical and experimental study of TMJ distraction: preliminary results.

PubMed

Festa, F; Galluccio, G

1998-01-01

A physiotherapeutic approach, with manual maneuvers and/or distraction appliances, is indicated in the treatment of temporomandibular joint disorders (TMDs) to prevent the progressive fibrosis of the muscle fibers. In this article, the authors report preliminary results of experimental and clinical studies conducted to assess the real effect of distraction in temporomandibular joint disorders. The experimental invivo studies confirmed the structural alteration due to compression and distraction on the capsular and condylar tissues. Clinical cases are reported to show the increase of the intraarticular vertical dimension, with a forward and downward movement of the condyles in a more physiologic condition.

Experimental results for a hypersonic nozzle/afterbody flow field

NASA Technical Reports Server (NTRS)

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

1995-01-01

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.

An Experimental Project on Energy Education for Rural Women, Primary School Children and Teachers Report.

ERIC Educational Resources Information Center

Pathak, Yogini; Mankodi, Hina

One of the University of Baroda's (India) Rural/Tribal Block Placement Program's major aims during the year 1988-89 was to develop energy consciousness in women, primary school children and teachers. An experimental project was designed for a rural Indian village. The objectives were to obtain information on rural energy resources; assess the role…

The National Ignition Facility Status and Plans for Laser Fusion and High Energy Density Experimental Studies

NASA Astrophysics Data System (ADS)

Wuest, Craig R.

2001-03-01

The National Ignition Facility (NIF) currently under construction at the University of California Lawrence Livermore National Laboratory is 192-beam, 1.8 Megajoule, 500 Terawatt, 351 nm laser for inertial confinement fusion and high energy density experimental studies. NIF is being built by the Department of Energy and the National Nuclear Security Agency to provide an experimental test bed for the US Stockpile Stewardship Program to ensure the country’s nuclear deterrent without underground nuclear testing. The experimental program for NIF will encompass a wide range of physical phenomena from fusion energy production to materials science. Of the roughly 700 shots available per year, about 10% of the shots will be dedicated to basic science research. Additionally, most of the shots on NIF will be conducted in unclassified configurations that will allow participation from the greater scientific community in planned applied physics experiments. This presentation will provide a look at the status of the construction project as well as a description of the scientific uses of NIF. NIF is currently scheduled to provide first light in 2004 and will be completed in 2008. This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

Mechanical properties of triaxially braided composites: Experimental and analytical results

NASA Technical Reports Server (NTRS)

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

1992-01-01

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.

Mechanical properties of triaxially braided composites: Experimental and analytical results

NASA Technical Reports Server (NTRS)

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

1992-01-01

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.

Experimental estimates of the energy budget of hydrothermal eruptions; application to 2012 Upper Te Maari eruption, New Zealand

NASA Astrophysics Data System (ADS)

Montanaro, Cristian; Scheu, Bettina; Cronin, Shane J.; Breard, Eric C. P.; Lube, Gert; Dingwell, Donald B.

2016-10-01

Sudden hydrothermal eruptions occur in many volcanic settings and may include high-energy explosive phases. Ballistics launched by such events, together with ash plumes and pyroclastic density currents, generate deadly proximal hazards. The violence of hydrothermal eruptions (or explosive power) depends on the energy available within the driving-fluids (gas or liquid), which also influences the explosive mechanisms, volumes, durations, and products of these eruptions. Experimental studies in addition to analytical modeling were used here to elucidate the fragmentation mechanism and aspects of energy balance within hydrothermal eruptions. We present results from a detailed study of recent event that occurred on the 6th of August 2012 at Upper Te Maari within the Tongariro volcanic complex (New Zealand). The eruption was triggered by a landslide from this area, which set off a rapid stepwise decompression of the hydrothermal system. Explosive blasts were directed both westward and eastward of the collapsed area, with a vertical ash plume sourced from an adjacent existing crater. All explosions ejected blocks on ballistic trajectories, hundreds of which impacted New Zealand's most popular hiking trail and a mountain lodge, 1.4 km from the explosion locus. We have employed rocks representative of the eruption source area to perform rapid decompression experiments under controlled laboratory conditions that mimic hydrothermal explosions under controlled laboratory conditions. An experimental apparatus for 34 by 70 mm cylindrical samples was built to reduce the influence of large lithic enclaves (up to 30 mm in diameter) within the rock. The experiments were conducted in a temperature range of 250 °C-300 °C and applied pressure between 4 MPa and 6.5 MPa, which span the range of expected conditions below the Te Maari crater. Within this range we tested rapid decompression of pre-saturated samples from both liquid-dominated conditions and the vapor-dominated field

Experimental and Computational Investigations of Phase Change Thermal Energy Storage Canisters

NASA Technical Reports Server (NTRS)

Ibrahim, Mounir; Kerslake, Thomas; Sokolov, Pavel; Tolbert, Carol

1996-01-01

Two sets of experimental data are examined in this paper, ground and space experiments, for cylindrical canisters with thermal energy storage applications. A 2-D computational model was developed for unsteady heat transfer (conduction and radiation) with phase-change. The radiation heat transfer employed a finite volume method. The following was found in this study: (1) Ground Experiments: the convection heat transfer is equally important to that of the radiation heat transfer; radiation heat transfer in the liquid is found to be more significant than that in the void; including the radiation heat transfer in the liquid resulted in lower temperatures (about 15 K) and increased the melting time (about 10 min.); generally, most of the heat flow takes place in the radial direction. (2) Space Experiments: radiation heat transfer in the void is found to be more significant than that in the liquid (exactly the opposite to the Ground Experiments); accordingly, the location and size of the void affects the performance considerably; including the radiation heat transfer in the void resulted in lower temperatures (about 40 K).

Composite Failures: A Comparison of Experimental Test Results and Computational Analysis Using XFEM

DTIC Science & Technology

2016-09-30

NUWC-NPT Technical Report 12,218 30 September 2016 Composite Failures: A Comparison of Experimental Test Results and Computational Analysis...A Comparison of Experimental Test Results and Computational Analysis Using XFEM 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...availability of measurement techniques, experimental testing of composite materials has largely outpaced the computational modeling ability, forcing

Save Energy Now Assessments Results 2008 Summary Report

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

Wright, Anthony L; Martin, Michaela A; Nimbalkar, Sachin U

assessment process at the company's other facilities. Another important element of the Save Energy Now assessment process is the follow-up process used to identify how many of the recommended savings opportunities from individual assessments have been implemented in the industrial plants. Plant personnel involved with the Save Energy Now assessments are contacted 6 months, 12 months, and 24 months after individual assessments are completed to determine implementation results. A total of 260 Save Energy Now assessments were successfully completed in calendar year 2008. This means that a total of 718 assessments were completed in 2006, 2007, and 2008. As of July 2009, we have received a total of 239 summary reports from the ESAs that were conducted in year 2008. Hence, at the time that this report was prepared, 680 final assessment reports were completed (200 from year 2006, 241 from year 2007, and 239 from year 2008). The total identified potential cost savings from these 680 assessments ismore » $$1.1 billion per year, including natural gas savings of about 98 TBtu per year. These results, if fully implemented, could reduce CO{sub 2} emissions by about 8.9 million metric tons annually. When this report was prepared, data on implementation of recommended energy and cost savings measures from 488 Save Energy Now assessments were available. For these 488 plants, measures saving a total of $$147 million per year have been implemented, measures that will save $169 million per year are in the process of being implemented, and plants are planning implementation of measures that will save another $239 million per year. The implemented recommendations are already achieving total CO{sub 2} reductions of about 1.8 million metric tons per year. This report provides a summary of the key results for the Save Energy Now assessments completed in 2008; details of the 6-month, 12-month, and 24-month implementation results obtained to date; and an evaluation of these implementation results

Save Energy Now Assessments Results 2008 Detailed Report

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

Wright, Anthony L; Martin, Michaela A; Nimbalkar, Sachin U

assessment process at the company's other facilities. Another important element of the Save Energy Now assessment process is the follow-up process used to identify how many of the recommended savings opportunities from individual assessments have been implemented in the industrial plants. Plant personnel involved with the Save Energy Now assessments are contacted 6 months, 12 months, and 24 months after individual assessments are completed to determine implementation results. A total of 260 Save Energy Now assessments were successfully completed in calendar year 2008. This means that a total of 718 assessments were completed in 2006, 2007, and 2008. As of July 2009, we have received a total of 239 summary reports from the ESAs that were conducted in year 2008. Hence, at the time that this report was prepared, 680 final assessment reports were completed (200 from year 2006, 241 from year 2007, and 239 from year 2008). The total identified potential cost savings from these 680 assessments ismore » $$1.1 billion per year, including natural gas savings of about 98 TBtu per year. These results, if fully implemented, could reduce CO{sub 2} emissions by about 8.9 million metric tons annually. When this report was prepared, data on implementation of recommended energy and cost savings measures from 488 Save Energy Now assessments were available. For these 488 plants, measures saving a total of $$147 million per year have been implemented, measures that will save $169 million per year are in the process of being implemented, and plants are planning implementation of measures that will save another $239 million per year. The implemented recommendations are already achieving total CO{sub 2} reductions of about 1.8 million metric tons per year. This report provides a summary of the key results for the Save Energy Now assessments completed in 2008; details of the 6-month, 12-month, and 24-month implementation results obtained to date; and an evaluation of these implementation results

Experimental and numerical investigations of the impingement of an oblique liquid jet onto a superhydrophobic surface: energy transformation

NASA Astrophysics Data System (ADS)

Kibar, Ali

2016-02-01

This study presents the theory of impinging an oblique liquid jet onto a vertical superhydrophobic surface based on both experimental and numerical results. A Brassica oleracea leaf with a 160° apparent contact angle was used for the superhydrophobic surface. Distilled water was sent onto the vertical superhydrophobic surface in the range of 1750-3050 Reynolds number, with an inclination angle of 20°-40°, using a circular glass tube with a 1.75 mm inner diameter. The impinging liquid jet spread onto the surface governed by the inertia of the liquid and then reflected off the superhydrophobic surface due to the surface energy of the spreading liquid. Two different energy approaches, which have time-scale and per-unit length, were performed to determine transformation of the energy. The kinetic energy of the impinging liquid jet was transformed into the surface energy with an increasing interfacial surface area between the liquid and air during spreading. Afterwards, this surface energy of the spreading liquid was transformed into the reflection kinetic energy.

Modeling and experimental parametric study of a tri-leg compliant orthoplanar spring based multi-mode piezoelectric energy harvester

NASA Astrophysics Data System (ADS)

Dhote, Sharvari; Yang, Zhengbao; Zu, Jean

2018-01-01

This paper presents the modeling and experimental parametric study of a nonlinear multi-frequency broad bandwidth piezoelectric vibration-based energy harvester. The proposed harvester consists of a tri-leg compliant orthoplanar spring (COPS) and multiple masses with piezoelectric plates attached at three different locations. The vibration modes, resonant frequencies, and strain distributions are studied using the finite element analysis. The prototype is manufactured and experimentally investigated to study the effect of single as well as multiple light-weight masses on the bandwidth. The dynamic behavior of the harvester with a mass at the center is modeled numerically and characterized experimentally. The simulation and experimental results are in good agreement. A wide bandwidth with three close nonlinear vibration modes is observed during the experiments when four masses are added to the proposed harvester. The current generator with four masses shows a significant performance improvement with multiple nonlinear peaks under both forward and reverse frequency sweeps.

Results on the energy dependence of cosmic ray charge composition

NASA Technical Reports Server (NTRS)

Balasubrahmanyan, V. K.; Ormes, J. F.

1973-01-01

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.

Experimental results from a laboratory-scale molten salt thermocline storage

NASA Astrophysics Data System (ADS)

Seubert, Bernhard; Müller, Ralf; Willert, Daniel; Fluri, Thomas

2017-06-01

Single-tank storage presents a valid option for cost reduction in thermal energy storage systems. For low-temperature systems with water as storage medium this concept is widely implemented and tested. For high-temperature systems very limited experimental data are publicly available. To improve this situation a molten salt loop for experimental testing of a single-tank storage prototype was designed and built at Fraunhofer ISE. The storage tank has a volume of 0.4 m3 or a maximum capacity of 72 kWhth. The maximum charging and discharging power is 60 kW, however, a bypass flow control system enables to operate the system also at a very low power. The prototype was designed to withstand temperatures up to 550 °C. A cascaded insulation with embedded heating cables can be used to reduce the effect of heat loss on the storage which is susceptible to edge effects due to its small size. During the first tests the operating temperatures were adapted to the conditions in systems with thermal oil as heat transfer fluid and a smaller temperature difference. A good separation between cold and hot fluid was achieved with temperature gradients of 95 K within 16 cm.

Experimental Investigation of A Heat Pipe-Assisted Latent Heat Thermal Energy Storage System

NASA Astrophysics Data System (ADS)

Tiari, Saeed; Mahdavi, Mahboobe; Qiu, Songgang

2016-11-01

In the present work, different operation modes of a latent heat thermal energy storage system assisted by a heat pipe network were studied experimentally. Rubitherm RT55 enclosed by a vertical cylindrical container was used as the Phase Change Material (PCM). The embedded heat pipe network consisting of a primary heat pipe and an array of four secondary heat pipes were employed to transfer heat to the PCM. The primary heat pipe transports heat from the heat source to the heat sink. The secondary heat pipes transfer the extra heat from the heat source to PCM during charging process or retrieve thermal energy from PCM during discharging process. The effects of heat transfer fluid (HTF) flow rate and temperature on the thermal performance of the system were investigated for both charging and discharging processes. It was found that the HTF flow rate has a significant effect on the total charging time of the system. Increasing the HTF flow rate results in a remarkable increase in the system input thermal power. The results also showed that the discharging process is hardly affected by the HTF flow rate but HTF temperature plays an important role in both charging and discharging processes. The authors would like to acknowledge the financial supports by Temple University for the project.

Experimental results of superimposing 9.9 GHz extraordinary mode microwaves on 2.45 GHz ECRIS plasma

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

Nishiokada, Takuya, E-mail: nishiokada@nf.eie.eng.osaka-u.ac.jp; Nagaya, Tomoki; Hagino, Shogo

2016-02-15

Efficient production of multicharged ions has been investigated on the tandem-type ECRIS in Osaka University. According to the consideration of the accessibility conditions of microwaves to resonance and cutoff regions, it was suggested that the upper hybrid resonance (UHR) heating contributed to enhancement of ion beam intensity. In order to enhance multicharged ion beams efficiently, injecting higher frequency microwave with extraordinary (X-mode) toward UHR region has been tried. In this study, 2.45 GHz frequency microwaves are used for conventional ECR discharge, and 9.9 GHz frequency microwaves with X-mode are superimposed for UHR heating. The effects of additive microwave injection aremore » investigated experimentally in terms of plasma parameters and electron energy distribution function (EEDF) measured by Langmuir probe and ion beam current. As the results show, it is confirmed that the electrons in the high energy region are affected by 9.9 GHz X-mode microwave injection from the detailed analysis of EEDF.« less

Experimental results of superimposing 9.9 GHz extraordinary mode microwaves on 2.45 GHz ECRIS plasma.

PubMed

Nishiokada, Takuya; Nagaya, Tomoki; Hagino, Shogo; Otsuka, Takuro; Muramatsu, Masayuki; Sato, Fuminobu; Kitagawa, Atsushi; Kato, Yushi

2016-02-01

Efficient production of multicharged ions has been investigated on the tandem-type ECRIS in Osaka University. According to the consideration of the accessibility conditions of microwaves to resonance and cutoff regions, it was suggested that the upper hybrid resonance (UHR) heating contributed to enhancement of ion beam intensity. In order to enhance multicharged ion beams efficiently, injecting higher frequency microwave with extraordinary (X-mode) toward UHR region has been tried. In this study, 2.45 GHz frequency microwaves are used for conventional ECR discharge, and 9.9 GHz frequency microwaves with X-mode are superimposed for UHR heating. The effects of additive microwave injection are investigated experimentally in terms of plasma parameters and electron energy distribution function (EEDF) measured by Langmuir probe and ion beam current. As the results show, it is confirmed that the electrons in the high energy region are affected by 9.9 GHz X-mode microwave injection from the detailed analysis of EEDF.

On the Dielectric Constant for Acetanilide: Experimental Measurements and Effect on Energy Transport

NASA Astrophysics Data System (ADS)

Careri, G.; Compatangelo, E.; Christiansen, P. L.; Halding, J.; Skovgaard, O.

1987-01-01

Experimental measurements of the dielectric constant for crystalline acetanilide powder for temperatures ranging from - 140°C to 20°C and for different hydration levels are presented. A Davydov-soliton computer model predicts dramatic changes in the energy transport and storage for typically increased values of the dielectric constant.

Experimental investigation of low aspect ratio, large amplitude, aeroelastic energy harvesting systems

NASA Astrophysics Data System (ADS)

Kirschmeier, Benjamin; Summerour, Jacob; Bryant, Matthew

2017-04-01

Interest in clean, stable, and renewable energy harvesting devices has increased dramatically with the volatility of petroleum markets. Specifically, research in aero/hydro kinetic devices has created numerous new horizontal and vertical axis wind turbines, and oscillating wing turbines. Oscillating wing turbines (OWTs) differ from their wind turbine cousins by having a rectangular swept area compared to a circular swept area. The OWT systems also possess a lower tip speed that reduces the overall noise produced by the system. OWTs have undergone significant computational analysis to uncover the underlying flow physics that can drive the system to high efficiencies for single wing oscillations. When two of these devices are placed in tandem configuration, i.e. one placed downstream of the other, they either can constructively or destructively interact. When constructive interactions occurred, they enhance the system efficiency to greater than that of two devices on their own. A new experimental design investigates the dependency of interaction modes on the pitch stiffness of the downstream wing. The experimental results demonstrated that interaction modes are functions of convective time scale and downstream wing pitch stiffness. Heterogeneous combinations of pitch stiffness exhibited constructive and destructive lock-in phenomena whereas the homogeneous combination exhibited only destructive interactions.

Experimental and modeling results of creep fatigue life of Inconel 617 and Haynes 230 at 850 C

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

Chen, Xiang; Sokolov, Mikhail A; Sham, Sam

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 formore » 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.« less

[Interactions of DNA bases with individual water molecules. Molecular mechanics and quantum mechanics computation results vs. experimental data].

PubMed

Gonzalez, E; Lino, J; Deriabina, A; Herrera, J N F; Poltev, V I

2013-01-01

To elucidate details of the DNA-water interactions we performed the calculations and systemaitic search for minima of interaction energy of the systems consisting of one of DNA bases and one or two water molecules. The results of calculations using two force fields of molecular mechanics (MM) and correlated ab initio method MP2/6-31G(d, p) of quantum mechanics (QM) have been compared with one another and with experimental data. The calculations demonstrated a qualitative agreement between geometry characteristics of the most of local energy minima obtained via different methods. The deepest minima revealed by MM and QM methods correspond to water molecule position between two neighbor hydrophilic centers of the base and to the formation by water molecule of hydrogen bonds with them. Nevertheless, the relative depth of some minima and peculiarities of mutual water-base positions in' these minima depend on the method used. The analysis revealed insignificance of some differences in the results of calculations performed via different methods and the importance of other ones for the description of DNA hydration. The calculations via MM methods enable us to reproduce quantitatively all the experimental data on the enthalpies of complex formation of single water molecule with the set of mono-, di-, and trimethylated bases, as well as on water molecule locations near base hydrophilic atoms in the crystals of DNA duplex fragments, while some of these data cannot be rationalized by QM calculations.

Experimental Investigation of Irregular Wave Cancellation Using a Cycloidal Wave Energy Converter

DTIC Science & Technology

2012-07-01

83388 EXPERIMENTAL INVESTIGATION OF IRREGULAR WAVE CANCELLATION USING A CYCLOIDAL WAVE ENERGY CONVERTER Stefan G. Siegel∗ Department of Aeronautics...United States Air Force Academy Air Force Academy, Colorado, 80840 USA Email: stefan @siegels.us Casey Fagley Department of Aeronautics United States Air...would like to acknowledge fruitful discussion with Dr. Jürgen Seidel and Dr. Tiger Jeans. This material is based upon activities supported by the

Photoinduced Electronic Energy Transfer: Theoretical and Experimental Issues for Light Harvesting Applications

DTIC Science & Technology

2013-10-21

PHOTOINDUCED ELECTRONIC ENERGY TRANSFER - THEORETICAL AND EXPERIMENTAL ISSUES FOR LIGHT HARVESTING APPLICATIONS PAUL BRUMER UNIV OF TORONTO 10/21... Applications 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-10-1-0260 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...Harvesting Applications Grant Number: FA9550-10-1-0260 Program Manager: Dr. Tatjana Curcic, AFOSR Stated aims of the project

An environmental friendly animal waste disposal process with ammonia recovery and energy production: Experimental study and economic analysis.

PubMed

Shen, Ye; Tan, Michelle Ting Ting; Chong, Clive; Xiao, Wende; Wang, Chi-Hwa

2017-10-01

Animal manure waste is considered as an environmental challenge especially in farming areas mainly because of gaseous emission and water pollution. Among all the pollutants emitted from manure waste, ammonia is of greatest concern as it could contribute to formation of aerosols in the air and could hardly be controlled by traditional disposal methods like landfill or composting. On the other hand, manure waste is also a renewable source for energy production. In this work, an environmental friendly animal waste disposal process with combined ammonia recovery and energy production was proposed and investigated both experimentally and economically. Lab-scale feasibility study results showed that 70% of ammonia in the manure waste could be converted to struvite as fertilizer, while solid manure waste was successfully gasified in a 10kW downdraft fixed-bed gasifier producing syngas with the higher heating value of 4.9MJ/(Nm 3 ). Based on experimental results, economic study for the system was carried out using a cost-benefit analysis to investigate the financial feasibility based on a Singapore case study. In addition, for comparison, schemes of gasification without ammonia removal and incineration were also studied for manure waste disposal. The results showed that the proposed gasification-based manure waste treatment process integrated with ammonia recovery was most financially viable. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental and analytical parametric study of single-crystal unimorph beams for vibration energy harvesting.

PubMed

Karami, M Amin; Bilgen, Onur; Inman, Daniel J; Friswell, Michael I

2011-07-01

This research presents an experimental and theoretical energy harvesting characterization of beam-like, uniform cross-section, unimorph structures employing single-crystal piezoelectrics. Different piezoelectric materials, substrates, and configurations are examined to identify the best design configuration for lightweight energy harvesting devices for low-power applications. Three types of piezoelectrics (singlecrystal PMN-PZT, polycrystalline PZT-5A, and PZT-5H-type monolithic ceramics) are evaluated in a unimorph cantilevered beam configuration. The devices have been excited by harmonic base acceleration. All of the experimental characteristics have been used to validate an exact electromechanical model of the harvester. The study shows the optimum choice of substrate material for single-crystal piezoelectric energy harvesting. Comparison of energy scavengers with stainless steel substrates reveals that single-crystal harvesters produce superior power compared with polycrystalline devices. To further optimize the power harvesting, we study the relation between the thickness of the substrate and the power output for different substrate materials. The relation between power and substrate thickness profoundly varies among different substrate materials. The variation is understood by examining the change of mechanical transmissibility and the variations of the coupling figure of merit of the harvesters with thickness ratio. The investigation identifies the optimal thickness of the substrate for different substrate materials. The study also shows that the densities of the substrates and their mechanical damping coefficients have significant effects on the power output.

Using experimental data to test an n -body dynamical model coupled with an energy-based clusterization algorithm at low incident energies

NASA Astrophysics Data System (ADS)

Kumar, Rohit; Puri, Rajeev K.

2018-03-01

Employing the quantum molecular dynamics (QMD) approach for nucleus-nucleus collisions, we test the predictive power of the energy-based clusterization algorithm, i.e., the simulating annealing clusterization algorithm (SACA), to describe the experimental data of charge distribution and various event-by-event correlations among fragments. The calculations are constrained into the Fermi-energy domain and/or mildly excited nuclear matter. Our detailed study spans over different system masses, and system-mass asymmetries of colliding partners show the importance of the energy-based clusterization algorithm for understanding multifragmentation. The present calculations are also compared with the other available calculations, which use one-body models, statistical models, and/or hybrid models.

Experimental Results for Temporally Overlapping Pulses from Quantel EverGreen 200 Laser

NASA Technical Reports Server (NTRS)

Watkins, A. Neal

2013-01-01

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.

Correlation of analytical and experimental hot structure vibration results

NASA Technical Reports Server (NTRS)

Kehoe, Michael W.; Deaton, Vivian C.

1993-01-01

High surface temperatures and temperature gradients can affect the vibratory characteristics and stability of aircraft structures. Aircraft designers are relying more on finite-element model analysis methods to ensure sufficient vehicle structural dynamic stability throughout the desired flight envelope. Analysis codes that predict these thermal effects must be correlated and verified with experimental data. Experimental modal data for aluminum, titanium, and fiberglass plates heated at uniform, nonuniform, and transient heating conditions are presented. The data show the effect of heat on each plate's modal characteristics, a comparison of predicted and measured plate vibration frequencies, the measured modal damping, and the effect of modeling material property changes and thermal stresses on the accuracy of the analytical results at nonuniform and transient heating conditions.

Experimental Results for Titan Aerobot Thermo-Mechanical Subsystem Development

NASA Technical Reports Server (NTRS)

Pauken, Michael T.; Hall, Jeffery L.

2006-01-01

This paper presents experimental results on a set of 4 thermo-mechanical research tasks aimed at Titan and Venus aerobots: 1. A cryogenic balloon materials development program culminating in the fabrication and testing of a 4.6 m long blimp prototype at 93K. 2. A combined computational and experimental thermal analysis of the effect of radioisotope power system (RPS) waste heat on the behavior of a helium filled blimp hull. 3. Aerial deployment and inflation testing using a blimp 4. A proof of concept experiment with an aerobot-mounted steerable high gain antenna These tasks were supported with JPL internal R&D funds and executed by JPL engineers with substantial industry collaboration for Task #1, the cryogenic balloon materials

Experimental verification of an energy consumption signal tool for operational decision support in an office building

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

Pavlak, Gregory S.; Henze, Gregor P.; Hirsch, Adam I.

This paper demonstrates an energy signal tool to assess the system-level and whole-building energy use of an office building in downtown Denver, Colorado. The energy signal tool uses a traffic light visualization to alert a building operator to energy use which is substantially different from expected. The tool selects which light to display for a given energy end-use by comparing measured energy use to expected energy use, accounting for uncertainty. A red light is only displayed when a fault is likely enough, and abnormal operation costly enough, that taking action will yield the lowest cost result. While the theoretical advancesmore » and tool development were reported previously, it has only been tested using a basic building model and has not, until now, been experimentally verified. Expected energy use for the field demonstration is provided by a compact reduced-order representation of the Alliance Center, generated from a detailed DOE-2.2 energy model. Actual building energy consumption data is taken from the summer of 2014 for the office building immediately after a significant renovation project. The purpose of this paper is to demonstrate a first look at the building following its major renovation compared to the design intent. The tool indicated strong under-consumption in lighting and plug loads and strong over-consumption in HVAC energy consumption, which prompted several focused actions for follow-up investigation. In addition, this paper illustrates the application of Bayesian inference to the estimation of posterior parameter probability distributions to measured data. Practical discussion of the application is provided, along with additional findings from further investigating the significant difference between expected and actual energy consumption.« less

Numerical and Experimental Investigation on a Thermo-Photovoltaic Module for Higher Efficiency Energy Generation

NASA Astrophysics Data System (ADS)

Karami-Lakeh, Hossein; Hosseini-Abardeh, Reza; Kaatuzian, Hassan

2017-05-01

One major problem of solar cells is the decrease in efficiency due to an increase in temperature when operating under constant irradiation of solar energy. The combination of solar cell and a thermoelectric generator is one of the methods proposed to solve this problem. In this paper, the performance of thermo-photovoltaic system is studied experimentally as well as through numerical simulation. In the experimental part, design, manufacture and test of a novel thermo-photovoltaic system assembly are presented. Results of the assembled system showed that with reduction of one degree (Centigrade) in the temperature of solar cell under investigation, and about 0.2 % increase in the efficiency will be obtained in comparison with given efficiency at that specified temperature. The solar cell in a hybrid-assembled system under two cooling conditions (air cooling and water cooling) obtained an efficiency of 8 % and 9.5 %, respectively, while the efficiency of a single cell under the same radiation condition was 6 %. In numerical simulation part, photo-thermoelectric performance of system was analyzed. Two methods for evaluation of thermoelectric performance were used: average properties and finite element method. Results of simulation also demonstrate an increase in solar cell efficiency in the combined system in comparison with that of the single cell configuration.

Experimental Determination of in Situ Utilization of Lunar Regolith for Thermal Energy Storage

NASA Technical Reports Server (NTRS)

Richter, Scott W.

1993-01-01

A Lunar Thermal Energy from Regolith (LUTHER) experiment has been designed and fabricated at the NASA Lewis Research Center to determine the feasibility of using lunar soil as thermal energy storage media. The experimental apparatus includes an alumina ceramic canister (25.4 cm diameter by 45.7 cm length) which contains simulated lunar regolith, a heater (either radiative or conductive), 9 heat shields, a heat transfer cold jacket, and 19 type B platinum rhodium thermocouples. The simulated lunar regolith is a basalt, mined and processed by the University of Minnesota, that closely resembles the lunar basalt returned to earth by the Apollo missions. The experiment will test the effects of vacuum, particle size, and density on the thermophysical properties of the regolith. The properties include melt temperature (range), specific heat, thermal conductivity, and latent heat of storage. Two separate tests, using two different heaters, will be performed to study the effect of heating the system using radiative and conductive heat transfer. The physical characteristics of the melt pattern, material compatibility of the molten regolith, and the volatile gas emission will be investigated by heating a portion of the lunar regolith to its melting temperature (1435 K) in a 10(exp -4) pascal vacuum chamber, equipped with a gas spectrum analyzer. A finite differencing SINDA model was developed at NASA Lewis Research Center to predict the performance of the LUTHER experiment. The analytical results of the code will be compared with the experimental data generated by the LUTHER experiment. The code will predict the effects of vacuum, particle size, and density has on the heat transfer to the simulated regolith.

FreeSolv: A database of experimental and calculated hydration free energies, with input files

PubMed Central

Mobley, David L.; Guthrie, J. Peter

2014-01-01

This work provides a curated database of experimental and calculated hydration free energies for small neutral molecules in water, along with molecular structures, input files, references, and annotations. We call this the Free Solvation Database, or FreeSolv. Experimental values were taken from prior literature and will continue to be curated, with updated experimental references and data added as they become available. Calculated values are based on alchemical free energy calculations using molecular dynamics simulations. These used the GAFF small molecule force field in TIP3P water with AM1-BCC charges. Values were calculated with the GROMACS simulation package, with full details given in references cited within the database itself. This database builds in part on a previous, 504-molecule database containing similar information. However, additional curation of both experimental data and calculated values has been done here, and the total number of molecules is now up to 643. Additional information is now included in the database, such as SMILES strings, PubChem compound IDs, accurate reference DOIs, and others. One version of the database is provided in the Supporting Information of this article, but as ongoing updates are envisioned, the database is now versioned and hosted online. In addition to providing the database, this work describes its construction process. The database is available free-of-charge via http://www.escholarship.org/uc/item/6sd403pz. PMID:24928188

Experimental and computational results from a large low-speed centrifugal impeller

NASA Technical Reports Server (NTRS)

Hathaway, M. D.; Chriss, R. M.; Wood, J. R.; Strazisar, A. J.

1993-01-01

An experimental and computational investigation of the NASA Low-Speed Centrifugal Compressor (LSCC) flow field has been conducted using laser anemometry and Dawes' 3D viscous code. The experimental configuration consists of a backswept impeller followed by a vaneless diffuser. Measurements of the three-dimensional velocity field were acquired at several measurement planes through the compressor. The measurements describe both the throughflow and secondary velocity field along each measurement plane and in several cases provide details of the flow within the blade boundary layers. The experimental and computational results provide a clear understanding of the development of the throughflow momentum wake which is characteristic of centrifugal compressors.

Experimental Analysis of Voltage Drop Compensation in a DC Electrified Railway by Introducing an Energy Storage System Incorporating EDLCs

NASA Astrophysics Data System (ADS)

Konishi, Takeshi; Hase, Shin-Ichi; Nakamichi, Yoshinobu; Nara, Hidetaka; Uemura, Tadashi

Interest has been shown in the concept of an energy storage system aimed at leveling load and improving energy efficiency by charging during vehicle regeneration and discharging during running. Such a system represents an efficient countermeasure against pantograph point voltage drop, power load fluctuation and regenerative power loss. We selected an EDLC model as an energy storage medium and a step-up/step-down chopper as a power converter to exchange power between the storage medium and overhead lines. Basic verification was conducted using a mini-model for DC 400V, demonstrating characteristics suitable for its use as an energy storage system. Based on these results, an energy storage system was built for DC 600V and a verification test conducted in conjunction with the Enoshima Electric Railway Co. Ltd. This paper gives its experimental analysis of voltage drop compensation in a DC electrified railway and some discussions based on the test.

An Experimental Study on the Shear Hysteresis and Energy Dissipation of the Steel Frame with a Trapezoidal-Corrugated Steel Plate.

PubMed

Shon, Sudeok; Yoo, Mina; Lee, Seungjae

2017-03-06

The steel frame reinforced with steel shear wall is a lateral load resisting system and has higher strength and shear performance than the concrete shear wall system. Especially, using corrugated steel plates in these shear wall systems improves out-of-plane stiffness and flexibility in the deformation along the corrugation. In this paper, a cyclic loading test of this steel frame reinforced with trapezoidal-corrugated steel plate was performed to evaluate the structural performance. The hysteresis behavior and the energy dissipation capacity of the steel frame were also compared according to the corrugated direction of the plate. For the test, one simple frame model without the wall and two frame models reinforced with the plate are considered and designed. The test results showed that the model reinforced with the corrugated steel plate had a greater accumulated energy dissipation capacity than the experimental result of the non-reinforced model. Furthermore, the energy dissipation curves of two reinforced frame models, which have different corrugated directions, produced similar results.

Experimental energy consumption of Frame Slotted ALOHA and Distributed Queuing for data collection scenarios.

PubMed

Tuset-Peiro, Pere; Vazquez-Gallego, Francisco; Alonso-Zarate, Jesus; Alonso, Luis; Vilajosana, Xavier

2014-07-24

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.

Snap-through twinkling energy generation through frequency up-conversion

NASA Astrophysics Data System (ADS)

Panigrahi, Smruti R.; Bernard, Brian P.; Feeny, Brian F.; Mann, Brian P.; Diaz, Alejandro R.

2017-07-01

A novel experimental energy harvester is investigated for its energy harvesting capability by frequency up-conversion using snap-through structures. In particular, a single-degree-of-freedom (SDOF) experimental energy harvester model is built using a snap-through nonlinear element. The snap-through dynamics is facilitated by the experimental setup of a twinkling energy generator (TEG) consisting of linear springs and attracting cylindrical bar magnets. A cylindrical coil of enamel-coated magnet wire is used as the energy generator. The governing equations are formulated mathematically and solved numerically for a direct comparison with the experimental results. The experimental TEG and the numerical simulation results show 25-fold frequency up-conversion and the power harvesting capacity of the SDOF TEG.

Observing Quantum Monodromy: AN Energy-Momentum Map Built from Experimentally-Determined Level Energies Obtained from the νb{7} Far-Infrared Band System of Ncncs

NASA Astrophysics Data System (ADS)

Tokaryk, Dennis W.; Ross, Stephen Cary; Winnewisser, Brenda P.; Winnewisser, Manfred; De Lucia, Frank C.; Billinghurst, Brant E.

2016-06-01

The concept of Quantum Monodromy (QM) provides a fresh insight into the structure of rovibrational levels in those flexible molecules for which a bending mode can carry the molecule through the linear configuration. To confirm the existence of QM in a molecule required the fruits of several strands of development: the formulation of the abstract mathematical concept of monodromy, including the exploration of its relevance to systems described by classical mechanics and its manifestation in quantum molecular applications; the development of the required spectroscopic technology and computer-aided assignment; and the development of a theoretical model to apply in fitting to the observed data. We present a timeline for each of these strands, converging in our initial confirmation of QM in NCNCS from pure rotational data alone. In that work a Generalised SemiRigid Bender (GSRB) Hamiltonian was fitted to the experimental rotational structure. Rovibrational energies calculated from the fitted GSRB parameters allowed us to construct an ``Energy-Momentum" map and confirm the presence of QM in NCNCS. In further experimental work at the Canadian Light Source Synchrotron we have identified a network of transitions directly connecting the relevant energy levels and thereby have produced a refined Energy Momentum map for NCNCS from experimental measurements alone. This map extends from the ground vibrational level to well above the potential energy barrier, beautifully illustrating the characteristic signature of QM in a system uncomplicated by interaction with other vibrational modes. B. P. Winnewisser et al., Phys. Rev. Lett. 95, 243002 (2005)

Ion velocity distribution functions in argon and helium discharges: detailed comparison of numerical simulation results and experimental data

NASA Astrophysics Data System (ADS)

Wang, Huihui; Sukhomlinov, Vladimir S.; Kaganovich, Igor D.; Mustafaev, Alexander S.

2017-02-01

Using the Monte Carlo collision method, we have performed simulations of ion velocity distribution functions (IVDF) taking into account both elastic collisions and charge exchange collisions of ions with atoms in uniform electric fields for argon and helium background gases. The simulation results are verified by comparison with the experiment data of the ion mobilities and the ion transverse diffusion coefficients in argon and helium. The recently published experimental data for the first seven coefficients of the Legendre polynomial expansion of the ion energy and angular distribution functions are used to validate simulation results for IVDF. Good agreement between measured and simulated IVDFs shows that the developed simulation model can be used for accurate calculations of IVDFs.

Unfolding linac photon spectra and incident electron energies from experimental transmission data, with direct independent validation

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

Ali, E. S. M.; McEwen, M. R.; Rogers, D. W. O.

2012-11-15

Purpose: In a recent computational study, an improved physics-based approach was proposed for unfolding linac photon spectra and incident electron energies from transmission data. In this approach, energy differentiation is improved by simultaneously using transmission data for multiple attenuators and detectors, and the unfolding robustness is improved by using a four-parameter functional form to describe the photon spectrum. The purpose of the current study is to validate this approach experimentally, and to demonstrate its application on a typical clinical linac. Methods: The validation makes use of the recent transmission measurements performed on the Vickers research linac of National Research Councilmore » Canada. For this linac, the photon spectra were previously measured using a NaI detector, and the incident electron parameters are independently known. The transmission data are for eight beams in the range 10-30 MV using thick Be, Al and Pb bremsstrahlung targets. To demonstrate the approach on a typical clinical linac, new measurements are performed on an Elekta Precise linac for 6, 10 and 25 MV beams. The different experimental setups are modeled using EGSnrc, with the newly added photonuclear attenuation included. Results: For the validation on the research linac, the 95% confidence bounds of the unfolded spectra fall within the noise of the NaI data. The unfolded spectra agree with the EGSnrc spectra (calculated using independently known electron parameters) with RMS energy fluence deviations of 4.5%. The accuracy of unfolding the incident electron energy is shown to be {approx}3%. A transmission cutoff of only 10% is suitable for accurate unfolding, provided that the other components of the proposed approach are implemented. For the demonstration on a clinical linac, the unfolded incident electron energies and their 68% confidence bounds for the 6, 10 and 25 MV beams are 6.1 {+-} 0.1, 9.3 {+-} 0.1, and 19.3 {+-} 0.2 MeV, respectively. The unfolded

Experimental and numerical study of two dimensional heat and mass transfer in unsaturated soil with and application to soil thermal energy storage (SBTES) systems

NASA Astrophysics Data System (ADS)

Moradi, A.; Smits, K. M.

2014-12-01

A promising energy storage option to compensate for daily and seasonal energy offsets is to inject and store heat generated from renewable energy sources (e.g. solar energy) in the ground, oftentimes referred to as soil borehole thermal energy storage (SBTES). Nonetheless in SBTES modeling efforts, it is widely recognized that the movement of water vapor is closely coupled to thermal processes. However, their mutual interactions are rarely considered in most soil water modeling efforts or in practical applications. The validation of numerical models that are designed to capture these processes is difficult due to the scarcity of experimental data, limiting the testing and refinement of heat and water transfer theories. A common assumption in most SBTES modeling approaches is to consider the soil as a purely conductive medium with constant hydraulic and thermal properties. However, this simplified approach can be improved upon by better understanding the coupled processes at play. Consequently, developing new modeling techniques along with suitable experimental tools to add more complexity in coupled processes has critical importance in obtaining necessary knowledge in efficient design and implementation of SBTES systems. The goal of this work is to better understand heat and mass transfer processes for SBTES. In this study, we implemented a fully coupled numerical model that solves for heat, liquid water and water vapor flux and allows for non-equilibrium liquid/gas phase change. This model was then used to investigate the influence of different hydraulic and thermal parameterizations on SBTES system efficiency. A two dimensional tank apparatus was used with a series of soil moisture, temperature and soil thermal properties sensors. Four experiments were performed with different test soils. Experimental results provide evidences of thermally induced moisture flow that was also confirmed by numerical results. Numerical results showed that for the test conditions

Experimental and modeling results of creep-fatigue life of Inconel 617 and Haynes 230 at 850 °C

NASA Astrophysics Data System (ADS)

Chen, Xiang; Sokolov, Mikhail A.; Sham, Sam; Erdman, Donald L., III; Busby, Jeremy T.; Mo, Kun; Stubbins, James F.

2013-01-01

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.

Experimental results on current-driven turbulence in plasmas - a survey

NASA Astrophysics Data System (ADS)

de Kluiver, H.; Perepelkin, N. F.; Hirose, A.

1991-01-01

The experimental consequences of plasma turbulence driven by a current parallel to a magnetic field and concurrent anomalous plasma heating are reviewed, with an attempt to deduce universalities in key parameters such as the anomalous electrical conductivities observed in diverse devices. It has been found that the nature of plasma turbulence and turbulent heating depends on several parameters including the electric field, current and magnetic fields. A classification of turbulence regimes based on these parameters has been made. Experimental observations of the anomalous electrical conductivity, plasma heating, skin effect, runaway electron braking and turbulent fluctuations are surveyed, and current theoretical understanding is briefly reviewed. Experimental results recently obtained in stellarators (SIRIUS, URAGAN at Kharkov), and in tokamaks (TORTUR at Nieuwegein, STOR-1M at Saskatoon) are presented in some detail in the light of investigating the feasibility of using turbulent heating as a means of injecting a large power into toroidal devices.

TH-CD-201-07: Experimentally Investigating Proton Energy Deposition On the Microscopic Scale Using Fluorescence Nuclear Track Detectors

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

Underwood, T; University College London, London; McFadden, C

Purpose: In order to further understand the interplay between proton physics and radiobiology it is necessary to consider proton energy deposition on the microscopic scale. In this work we used Fluorescent Nuclear Track Detectors (FNTDs) to experimentally investigate proton energy deposition, track-by-track. Methods: We irradiated 8×4×0.5mm{sup 3} FNTD chips (Landauer Inc) at seven water depths along a pristine proton Bragg peak with range=12cm. After irradiation, the FNTDs were scanned using a confocal microscope (FV1200, Olympus) with a high-power red laser and an oil-immersion objective lens (UPLSAPO60XO, NA=1.35). 10 slice image stacks were acquired with a slice-thickness of 2µm at multiplemore » positions across each FNTD. Image-based analyses of track radius and track “mass” (integrated signal intensity) were performed using trackpy. For comparison, Monte Carlo simulated data were obtained using TOPAS and TOPAS-nBio. Results: Excellent correlation was observed between median track mass and TOPAS dose-averaged linear energy transfer. The resolution of the imaging system was determined insufficient to detect a relationship between track radius and exposure depth. Histograms of track mass (i) displayed strong repeatability across positions within an FNTD and (ii) varied in peak position and shape as a function of depth. TOPAS-nBio simulations implemented on the nanometer scale using physics lists from GEANT4-DNA yielded energy deposition distributions for individual protons and electrons scored within a virtual FNTD. Good agreement was found between these simulated datasets and the FNTD track mass distributions. Conclusion: Robust experimental measurements of the integral energy deposited by individual proton tracks can be performed using FNTDs. Monte Carlo simulations offer an exceedingly powerful approach to the quantification of proton energy deposition on the microscopic scale, but whilst they have been well validated at the macroscopic level, their

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

NASA Technical Reports Server (NTRS)

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

1990-01-01

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.

Conservation of Mechanical and Electric Energy: Simple Experimental Verification

ERIC Educational Resources Information Center

Ponikvar, D.; Planinsic, G.

2009-01-01

Two similar experiments on conservation of energy and transformation of mechanical into electrical energy are presented. Both can be used in classes, as they offer numerous possibilities for discussion with students and are simple to perform. Results are presented and are precise within 20% for the version of the experiment where measured values…

Experimental evaluation of thermal and energy performance of temperate green roofs: a case study in Beijing

NASA Astrophysics Data System (ADS)

Sun, T.; Institute of Hydrology; Water Resources

2011-12-01

An experimental evaluation of thermal and energy performance of temperate green roofs was carried out by thermal and meteorological observation and energy budget modeling using a setup of green roof in Beijing urban area. From both the yearly and daily temperature trends, the green roof could effectively damp down the undulation of roof surface temperature comparing with the conventional one. As an insulating screen, the green roof abated the amplitude of temperature by 9.0 in winter and 9.1 °C in summer, respectively. Under different cloud conditions, the green roof in summer time resulted in decreases in sensible heat and heat flux by 125.3W m-2 and 32.0 W m-2, respectively, on daily average comparing with the conventional one. Based on the energy budget analyses, under an assumptive scenario of 50% roof-greening in Beijing, a total of 34.1 PJ of sensible heat and 8.7 PJ of heat flux would be decreased for a summer period of 90 days. This study demonstrated that green roof, serving as an insulating screen to building top in comparison with the conventional roof, proved thermal improving effect in building scale and high energy saving potential for urban development.

Design and experimental verification of an improved magnetostrictive energy harvester

NASA Astrophysics Data System (ADS)

Germer, M.; Marschner, U.; Flatau, A. B.

2017-04-01

This paper summarizes and extends the modeling state of the art of magnetostrictive energy harvesters with a focus on the pick-up coil design. The harvester is a one-sided clamped galfenol unimorph loaded with two brass pieces each containing a permanent magnet to create a biased magnetic field. Measurements on different pick-up coils were conducted and compared with results from an analytic model. Resistance, mass and inductance were formulated and proved by measurements. Both the length for a constant number of turns and the number of turns for a constant coil length were also modeled and varied. The results confirm that the output voltage depends on the coil length for a constant number of turns and is higher for smaller coils. In contrast to a uniform magnetic field, the maximal output voltage is gained if the coil is placed not directly at but near the fixation. Two effects explain this behavior: Due to the permanent magnet next to the fixation, the magnetic force is higher and orientates the magnetic domains stronger. The clamping locally increases the stress and forces the magnetic domains to orientate, too. For that reason the material is stiffer and therefore the strain smaller. The tradeoff between a higher induced voltage in the coil and an increasing inductance and resistance for every additional turn are presented together with an experimental validation of the models. Based on the results guidelines are given to design an optimal coil which maximizes the output power for a given unimorph.

Experimental determination of ice sublimation energies

NASA Astrophysics Data System (ADS)

Luna, R.; Canto, J.; Satorre, M. A.; Domingo, M.

2011-11-01

In Astrophysics, the study of ices is important due to the wide range of scenarios in which they are present. Their physical and chemical characteristics play an important role in the study of the interstellar medium (ISM). The assessment of the energy of sublimation allows us to improve our understanding of physical and/or chemical processes that take place where ices are present. The energy of sublimation E_sub is defined as the change of energy between solid and gas phase of certain molecule. This value is important to determinate other thermodynamical parameters such as the reticular energy of ionic compounds, the energy of formation in gas phase from the energy of formation in condensed phase, or to estimate the sublimation rate, which is very important in determining the evolution of surfaces of astrophysical objects.

A Review of Out-of-School Time Program Quasi-Experimental and Experimental Evaluation Results. Out-of-School Time Evaluation Snapshot.

ERIC Educational Resources Information Center

Little, Priscilla M. D.; Harris, Erin

As the amount of resources allocated to out-of-school (OST) programming and policymakers' demands for research-based results increase, there is increasing interest in rigorous research designs to examine OST program outcomes. This issue of "Out-of-School Time Evaluation Snapshots" reviews 27 quasi-experimental and experimental OST…

Focusing effect of bent GaAs crystals for γ-ray Laue lenses: Monte Carlo and experimental results

NASA Astrophysics Data System (ADS)

Virgilli, E.; Frontera, F.; Rosati, P.; Bonnini, E.; Buffagni, E.; Ferrari, C.; Stephen, J. B.; Caroli, E.; Auricchio, N.; Basili, A.; Silvestri, S.

2016-02-01

We report on results of observation of the focusing effect from the planes (220) of Gallium Arsenide (GaAs) crystals. We have compared the experimental results with the Monte Carlo simulations of the focusing capability of GaAs tiles performed with a dedicated ray-tracer. The GaAs tiles were bent using a lapping process developed at the cnr/imem - Parma (Italy) in the framework of the laue project, funded by ASI, dedicated to build a broad band Laue lens prototype for astrophysical applications in the hard X-/soft γ-ray energy range (80-600 keV). We present and discuss the results obtained from their characterization, mainly in terms of focusing capability. Bent crystals will significantly increase the signal to noise ratio of a telescope based on a Laue lens, consequently leading to an unprecedented enhancement of sensitivity with respect to the present non focusing instrumentation.

Electrical and thermal behavior of unsaturated soils: experimental results

NASA Astrophysics Data System (ADS)

Nouveau, Marie; Grandjean, Gilles; Leroy, Philippe; Philippe, Mickael; Hedri, Estelle; Boukcim, Hassan

2016-05-01

When soil is affected by a heat source, some of its properties are modified, and in particular, the electrical resistivity due to changes in water content. As a result, these changes affect the thermal properties of soil, i.e., its thermal conductivity and diffusivity. We experimentally examine the changes in electrical resistivity and thermal conductivity for four soils with different grain size distributions and clay content over a wide range of temperatures, from 20 to 100 °C. This temperature range corresponds to the thermal conditions in the vicinity of a buried high voltage cable or a geothermal system. Experiments were conducted at the field scale, at a geothermal test facility, and in the laboratory using geophysical devices and probing systems. The results show that the electrical resistivity decreases and the thermal conductivity increases with temperature up to a critical temperature depending on soil types. At this critical temperature, the air volume in the pore space increases with temperature, and the resulting electrical resistivity also increases. For higher temperatures , the thermal conductivity increases sharply with temperature up to a second temperature limit. Beyond it, the thermal conductivity drops drastically. This limit corresponds to the temperature at which most of the water evaporates from the soil pore space. Once the evaporation is completed, the thermal conductivity stabilizes. To explain these experimental results, we modeled the electrical resistivity variations with temperature and water content in the temperature range 20 - 100°C, showing that two critical temperatures influence the main processes occurring during heating at temperatures below 100 °C.

Entropic and Electrostatic Effects on the Folding Free Energy of a Surface-Attached Biomolecule: An Experimental and Theoretical Study

PubMed Central

Watkins, Herschel M.; Vallée-Bélisle, Alexis; Ricci, Francesco; Makarov, Dmitrii E.; Plaxco, Kevin W.

2012-01-01

Surface-tethered biomolecules play key roles in many biological processes and biotechnologies. However, while the physical consequences of such surface attachment have seen significant theoretical study, to date this issue has seen relatively little experimental investigation. In response we present here a quantitative experimental and theoretical study of the extent to which attachment to a charged –but otherwise apparently inert– surface alters the folding free energy of a simple biomolecule. Specifically, we have measured the folding free energy of a DNA stem loop both in solution and when site-specifically attached to a negatively charged, hydroxyl-alkane-coated gold surface. We find that, whereas surface attachment is destabilizing at low ionic strength it becomes stabilizing at ionic strengths above ~130 mM. This behavior presumably reflects two competing mechanisms: excluded volume effects, which stabilize the folded conformation by reducing the entropy of the unfolded state, and electrostatics, which, at lower ionic strengths, destabilizes the more compact folded state via repulsion from the negatively charged surface. To test this hypothesis we have employed existing theories of the electrostatics of surface-bound polyelectrolytes and the entropy of surface-bound polymers to model both effects. Despite lacking any fitted parameters, these theoretical models quantitatively fit our experimental results, suggesting that, for this system, current knowledge of both surface electrostatics and excluded volume effects is reasonably complete and accurate. PMID:22239220

An Experimental Study on the Shear Hysteresis and Energy Dissipation of the Steel Frame with a Trapezoidal-Corrugated Steel Plate

PubMed Central

Shon, Sudeok; Yoo, Mina; Lee, Seungjae

2017-01-01

The steel frame reinforced with steel shear wall is a lateral load resisting system and has higher strength and shear performance than the concrete shear wall system. Especially, using corrugated steel plates in these shear wall systems improves out-of-plane stiffness and flexibility in the deformation along the corrugation. In this paper, a cyclic loading test of this steel frame reinforced with trapezoidal-corrugated steel plate was performed to evaluate the structural performance. The hysteresis behavior and the energy dissipation capacity of the steel frame were also compared according to the corrugated direction of the plate. For the test, one simple frame model without the wall and two frame models reinforced with the plate are considered and designed. The test results showed that the model reinforced with the corrugated steel plate had a greater accumulated energy dissipation capacity than the experimental result of the non-reinforced model. Furthermore, the energy dissipation curves of two reinforced frame models, which have different corrugated directions, produced similar results. PMID:28772624

Experimental results in evolutionary fault-recovery for field programmable analog devices

NASA Technical Reports Server (NTRS)

Zebulum, Ricardo S.; Keymeulen, Didier; Duong, Vu; Guo, Xin; Ferguson, M. I.; Stoica, Adrian

2003-01-01

This paper presents experimental results of fast intrinsic evolutionary design and evolutionary fault recovery of a 4-bit Digital to Analog Converter (DAC) using the JPL stand-alone board-level evolvable system (SABLES).

Experimental results on the enhanced backscatter phenomenon and its dynamics

NASA Astrophysics Data System (ADS)

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

2014-10-01

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.

Overview of the Manitou Experimental Forest Observatory: Site description and selected science results from 2008 to 2013

Treesearch

J. Ortega; A. Turnipseed; A. B. Guenther; T. G. Karl; D. A. Day; D. Gochis; J. A. Huffman; A. J. Prenni; E. J. T. Levin; S. M. Kreidenweis; P. J. DeMott; Y. Tobo; E. G. Patton; A. Hodzic; Y. Y. Cui; P. C. Harley; R. S. Hornbrook; E. C. Apel; R. K. Monson; A. S. D. Eller; J. P. Greenberg; M. C. Barth; P. Campuzano-Jost; B. B. Palm; J. L. Jimenez; A. C. Aiken; M. K. Dubey; C. Geron; J. Offenberg; M. G. Ryan; P. J. Fornwalt; S. C. Pryor; F. N. Keutsch; J. P. DiGangi; A. W. H. Chan; A. H. Goldstein; G. M. Wolfe; S. Kim; L. Kaser; R. Schnitzhofer; A. Hansel; C. A. Cantrell; R. L. Mauldin; J. N. Smith

2014-01-01

The Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen (BEACHON) project seeks to understand the feedbacks and interrelationships between hydrology, biogenic emissions, carbon assimilation, aerosol properties, clouds and associated feedbacks within water-limited ecosystems. The Manitou Experimental Forest Observatory (MEFO) was...

Energy spectrum of medium energy gamma-rays from the galactic center region. [experimental design

NASA Technical Reports Server (NTRS)

Palmeira, R. A. R.; Ramanujarao, K.; Dutra, S. L. G.; Bertsch, D. L.; Kniffen, D. A.; Morris, D. J.

1978-01-01

A balloon-borne magnetic core digitized spark chamber with two assemblies of spark-chambers above and below the scintillation counters was used to measure the medium energy gamma ray flux from the galactic center region. Gamma ray calculations are based on the multiple scattering of the pair electrons in 15 aluminum plates interleaved in the spark chamber modules. Counting rates determined during ascent and at ceiling indicate the presence of diffuse component in this energy range. Preliminary results give an integral flux between 15 and 70 MeV compared to the differential points in other results.

A novel experimental animal model of arterial stenosis based on endovascular radiofrequency energy application.

PubMed

Lazoura, Olga; Zacharoulis, Dimitris; Kanavou, Theodora; Rountas, Christos; Katsimboulas, Michael; Tzovaras, George; Habib, Nagy

2011-01-01

To develop a new rabbit model of arterial stenosis using endovascular radiofrequency (RF) energy. Ten rabbits were used for multiple endovascular RF applications to the aorta and left common carotid artery through the Habib™ VesCoag™ catheter. Angiography and color Doppler ultrasound were used to assess vessel patency immediately following the procedure and six weeks later. One rabbit was sacrificed following the procedure for histopathologic analysis of the vessel wall. Two rabbits died of aortic and carotid rupture, respectively, immediately after the procedure. The remaining seven rabbits were sacrificed after six-week follow-up for histopathological analysis. Optimal RF generator settings to induce significant arterial stenosis (>50%) without complications were standardized at 24-26 watts (W) for 1.5 min for the aorta and 6 W for 1 min for the common carotid artery. The six-week follow-up showed permanent results in all surviving rabbits. Histopathology revealed intima and medial smooth muscle layer necrosis. We have developed a novel rabbit model of arterial stenosis using endovascular RF energy. Our model is fast, safe, inexpensive, and reproducible. It would be useful for experimental investigations and new therapeutic devices.

High accuracy experimental determination of copper and zinc mass attenuation coefficients in the 100 eV to 30 keV photon energy range

NASA Astrophysics Data System (ADS)

Ménesguen, Y.; Gerlach, M.; Pollakowski, B.; Unterumsberger, R.; Haschke, M.; Beckhoff, B.; Lépy, M.-C.

2016-02-01

The knowledge of atomic fundamental parameters such as mass attenuation coefficients with low uncertainties, is of decisive importance in elemental quantification using x-ray fluorescence analysis techniques. Several databases are accessible and frequently used within a large community of users. These compilations are most often in good agreement for photon energies in the hard x-ray ranges. However, they significantly differ for low photon energies and around the absorption edges of any element. In a joint cooperation of the metrology institutes of France and Germany, mass attenuation coefficients of copper and zinc were determined experimentally in the photon energy range from 100 eV to 30 keV by independent approaches using monochromatized synchrotron radiation at SOLEIL (France) and BESSY II (Germany), respectively. The application of high-accuracy experimental techniques resulted in mass attenuation coefficient datasets determined with low uncertainties that are directly compared to existing databases. The novel datasets are expected to enhance the reliability of mass attenuation coefficients.

Energy coding in biological neural networks

PubMed Central

Zhang, Zhikang

2007-01-01

According to the experimental result of signal transmission and neuronal energetic demands being tightly coupled to information coding in the cerebral cortex, we present a brand new scientific theory that offers an unique mechanism for brain information processing. We demonstrate that the neural coding produced by the activity of the brain is well described by our theory of energy coding. Due to the energy coding model’s ability to reveal mechanisms of brain information processing based upon known biophysical properties, we can not only reproduce various experimental results of neuro-electrophysiology, but also quantitatively explain the recent experimental results from neuroscientists at Yale University by means of the principle of energy coding. Due to the theory of energy coding to bridge the gap between functional connections within a biological neural network and energetic consumption, we estimate that the theory has very important consequences for quantitative research of cognitive function. PMID:19003513

Constraints on Coulomb energy, neutron skin thickness in 208Pb, and symmetry energy

NASA Astrophysics Data System (ADS)

Dong, J. M.; Wang, L. J.; Zuo, W.; Gu, J. Z.

2018-03-01

The charge-symmetry-breaking (CSB) effect in a nuclear medium that gives rise to the first-order symmetry energy in finite nuclei is discussed in detail in the present paper. For heavy and superheavy nuclei with large neutron excesses, it should be nonnegligible in high-precision mass predictions, and importantly it affects the stability of these nuclei. Combined with this CSB effect, the Coulomb energy is constrained by using the experimental Coulomb displacement energy of mirror nuclei, and then the mass-dependent symmetry energy coefficients of heavy nuclei are reextracted with the experimental β--decay energies of heavy odd-A nuclei and with the experimental mass differences. Based on these results, we probe the neutron skin thickness Δ Rn p of 208Pb and the density-dependent symmetry energy coefficient of nuclear matter. Δ Rn p in 208Pb is found to be 0.158 ±0.014 fm , and the slopes L of the symmetry energy coefficient at densities of ρ =0.16 and ρ =0.11 fm-3 are estimated to be 42 ±8 and 42 ±3 MeV , respectively. These results would be meaningful to discriminate between the models and the predictions that are relevant for the investigations on properties of nuclei and of neutron stars.

FIBER AND INTEGRATED OPTICS: Experimental investigation of energy transfer between modes in a graded-index fiber waveguide with periodic microbending of the axis

NASA Astrophysics Data System (ADS)

Garichev, V. P.; Krivoshlykov, S. G.; Jahn, I.-U.

1990-08-01

An experimental investigation was made of energy transfer between the lowest axially symmetric modes in a multimode graded-index fiber waveguide as a function of the amplitude of periodic bending of its axis. Selective excitation and detection of given modes in a waveguide was induced with the aid of synthesized holograms. The experimental curves were in satisfactory agreement with the results of a theoretical calculation and confirmed that the sensitivity of a mode to bending of the axis of a graded-index waveguide increased on increase in the mode number.

Analytical, Numerical, and Experimental Results on Turbulent Boundary Layers

DTIC Science & Technology

1976-07-01

a pitot pressure rake where the spacing between probe centers was 0.5 in. near the wall and 1.0 in. away from the wall. Recently, measurements have...Pressure Gradient, Part II. Analysis- of the Experimental Data." BRL R 1543, June 1971. 51. Allen, J. M. " Pitot -Probe Displacement in a Supersonic Turbulent...numbers; (4) a description of the data reduction of pitot pressure measurements utilizing these analytical results in order to obtain velocity

Design and experimental study of a velocity amplified electromagnetic vibration energy harvester

NASA Astrophysics Data System (ADS)

Klein, Jackson A.; Zuo, Lei

2017-04-01

Dedicated sensors are widely used throughout many industries to monitor everyday operations, maintain safety and report performance characteristics. In order to adopt a more sustainable solution, intensive research is being conducted for self-powered sensing. To enable sensors to power themselves, harvesting energy from environmental vibration has been widely studied, however, its overall effectiveness remains questionable due to small vibration amplitudes and thus limited harvestable energy density. This paper addresses the issue by proposing a novel vibration energy harvester in which a metal compliant mechanism frame is used to house both a linear electromagnetic generator and proof mass. Due to the compliant mechanism, the proposed energy harvester is capable of amplifying machine vibration velocity for a dedicated electromagnetic generator, largely increasing the energy density. The harvester prototype is also fabricated and experimentally characterized to verify its effectiveness. When operating at its natural frequency in a low base amplitude, 0.001 in (25.4μm) at 19.4 Hz, during lab tests, the harvester has been shown to produce up to 0.91 V AC open voltage, and a maximum power of 2 mW, amplifying the relative proof mass velocity by approximately 5.4 times. In addition, a mathematical model is created based on the pseudo-rigid-body dynamics and the analysis matches closely with experiments. The proposed harvester was designed using vibration data from nuclear power plants. Further steps for improving such a design are given for broader applications.

An experimental/computational study of sharp fin induced shock wave/turbulent boundary layer interactions at Mach 5 - Experimental results

NASA Technical Reports Server (NTRS)

Rodi, Patrick E.; Dolling, David S.

1992-01-01

A combined experimental/computational study has been performed of sharp fin induced shock wave/turbulent boundary layer interactions at Mach 5. The current paper focuses on the experiments and analysis of the results. The experimental data include mean surface heat transfer, mean surface pressure distributions and surface flow visualization for fin angles of attack of 6, 8, 10, 12, 14 and 16-degrees at Mach 5 under a moderately cooled wall condition. Comparisons between the results and correlations developed earlier show that Scuderi's correlation for the upstream influence angle (recast in a conical form) is superior to other such correlations in predicting the current results, that normal Mach number based correlations for peak pressure heat transfer are adequate and that the initial heat transfer peak can be predicted using pressure-interaction theory.

Modeling a photovoltaic energy storage system based on super capacitor, simulation and evaluation of experimental performance

NASA Astrophysics Data System (ADS)

Ben Fathallah, Mohamed Ali; Ben Othman, Afef; Besbes, Mongi

2018-02-01

Photovoltaic energy is very important to meet the consumption needs of electrical energy in remote areas and for other applications. Energy storage systems are essential to avoid the intermittent production of photovoltaic energy and to cover peaks in energy demand. The super capacitor, also known as electrochemical double layer capacitor, is a storage device which has a very high power density compared to conventional battery and is capable of storing a large amount of electrical energy in short time periods, which reflects its interest to be used for the storage of photovoltaic energy. From this principle, this paper represents a three-branch RC model of super capacitor to describe its different dynamics of operation during the charging, discharging and rest phases. After having validated the good functioning of this model with the experimental study of Zubieta, The super capacitor performance has been demonstrated and compared with a conventional battery in a photovoltaic converter chain to power AC machine.

On the complex relationship between energy expenditure and longevity: Reconciling the contradictory empirical results with a simple theoretical model.

PubMed

Hou, Chen; Amunugama, Kaushalya

2015-07-01

The relationship between energy expenditure and longevity has been a central theme in aging studies. Empirical studies have yielded controversial results, which cannot be reconciled by existing theories. In this paper, we present a simple theoretical model based on first principles of energy conservation and allometric scaling laws. The model takes into considerations the energy tradeoffs between life history traits and the efficiency of the energy utilization, and offers quantitative and qualitative explanations for a set of seemingly contradictory empirical results. We show that oxidative metabolism can affect cellular damage and longevity in different ways in animals with different life histories and under different experimental conditions. Qualitative data and the linearity between energy expenditure, cellular damage, and lifespan assumed in previous studies are not sufficient to understand the complexity of the relationships. Our model provides a theoretical framework for quantitative analyses and predictions. The model is supported by a variety of empirical studies, including studies on the cellular damage profile during ontogeny; the intra- and inter-specific correlations between body mass, metabolic rate, and lifespan; and the effects on lifespan of (1) diet restriction and genetic modification of growth hormone, (2) the cold and exercise stresses, and (3) manipulations of antioxidant. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Experimental test of a dynamically tuned wave energy converter based on inflatable dielectric elastomer generators (Conference Presentation)

NASA Astrophysics Data System (ADS)

Moretti, Giacomo; Vertechy, Rocco; Fontana, Marco

2017-04-01

Dielectric Elastomer Generators (DEGs) are very promising systems that are able to directly convert oscillating mechanical energy into direct electricity. Their nature and main attributes make them particularly interesting for harvesting energy form ocean waves. In this context, several efforts have been made in the last years to develop effective Wave Energy Converters based on DEG [1-4]. In this contribution, we present a novel Wave Energy Converter (WEC) based on the Oscillating Water Column principle. The device features an inflatable DEG as Power Take Off (PTO) system and collector - i.e. the part of the device that is directly interacting with waves - that possesses a coaxial-ducted shape as described in [5]. Models of the coupled behavior that consider the electro-hyperelastic response of the DEG and the hydrodynamics are presented. It is shown that the dynamic response and the effectiveness of the system can be largely improved through an appropriate dimensioning of the geometry of the device. Specifically, the dynamic response of the system can be designed to match the corresponding harmonic content of water waves achieving an effective conversion of the incoming mechanical energy. A small/intermediate scale prototype of the system is built and tested in a wave tank facility - i.e. a basin in which artificially controlled waves can be generated - available at Flowave (UK). Mathematical models are validated against experimental results for monochromatic and panchromatic tests. During the experiments, we obtained peak of estimated power output in the range of 1 W to 4 W with an energy density for the dielectric material of approximately 80-120W/kg. The achieved results represent a milestone in the study of WEC based on DEG, paving the path toward scaling up of this technology.

Experimental results of a new system using microwaves for vision correction

NASA Astrophysics Data System (ADS)

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

2009-02-01

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.

Select Results from the Energy Assessor Experiment in the 2012 Commercial Buildings Energy Consumption Survey

EIA Publications

2015-01-01

As part of an effort to make EIA’s energy consumption surveys as accurate and efficient as possible, EIA invited the National Research Council (NRC) to review the Commercial Buildings Energy Consumption Survey (CBECS) data-gathering process and make recommendations for improvements. The NRC suggested sending professional energy assessors to some sites and comparing the data obtained from the survey to the data collected by the assessors. Results from the energy assessment data collection have largely confirmed the quality of data gathered by CBECS interviewers.

Net energy content of canola meal fed to growing pigs and effect of experimental methodology on energy values.

PubMed

Kim, J W; Koo, B; Nyachoti, C M

2018-04-14

An experiment was conducted to determine the digestible energy (DE), metabolizable energy (ME), and net energy (NE) contents of canola meal (CM) and to investigate the effects of basal diet [corn diet vs. corn-soybean meal (SBM) diet] and methodology (difference method vs. regression method) on energy values of CM. Thirty-six growing barrows (20.8 ± 1.0 kg initial body weight [BW]) were individually housed in metabolism crates and randomly allotted to one of six dietary treatments to give six replicates per treatment. The six experimental diets included a corn diet, a corn-SBM diet, a corn diet with 15 or 30% of CM, and a corn-SBM diet with 15 or 30% of CM. The DE, ME, and NE of CM were determined using the corn diet or the corn-SBM diet as a basal diet. In each basal diet, two additional diets containing 15 or 30% of CM were formulated to compare the determined energy values by the difference method and estimated energy values from the regression method. Feeding level was set at 550 kcal ME/kg BW0.6 per day. Pigs were fed experimental diets for 16 d including 10 d for adaptation and 6 d for total collection of feces and urine. Pigs were then moved into indirect calorimetry chambers to determine 24 h heat production (HP) and 12 h fasting HP. The DE, ME, and NE of CM determined by the difference method were within the 95% confidence intervals estimated for the DE, ME, and NE of CM by the regression method regardless of the basal diets used, which indicates that the difference and regression methods give equivalent DE, ME, and NE of CM. However, when the goodness of fit for the linear model was compared, the r2 of the regression analysis from the corn-SBM diet (0.78) was relatively greater than that from corn diet (0.40). The estimated NE of CM by the prediction equations generated by either the corn diet or corn-SBM diets were 2,096 kcal/kg and 1,960 kcal/kg (as-fed basis), respectively, whereas those values determined by the difference method were 2,233 kcal

Experimental aspects of the thermochemical conversion of solar energy - Decarbonation of CaCO3

NASA Astrophysics Data System (ADS)

Flamant, G.; Hernandez, D.; Bonet, C.; Traverse, J.-P.

1980-01-01

The feasibility of thermochemical conversion of concentrated solar energy is investigated. Consideration is given to heterogeneous systems in the range 500-1500 C. A reaction volume is on a laboratory scale about 30 cu cm. An experimental set-up selected is a fluid bed and a rotary kiln. An endothermal reaction, namely, decarbonation of CaCO3, is selected as a possible application for solar power plants.

V&V of MCNP 6.1.1 Beta Against Intermediate and High-Energy Experimental Data

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

Mashnik, Stepan G

This report presents a set of validation and verification (V&V) MCNP 6.1.1 beta results calculated in parallel, with MPI, obtained using its event generators at intermediate and high-energies compared against various experimental data. It also contains several examples of results using the models at energies below 150 MeV, down to 10 MeV, where data libraries are normally used. This report can be considered as the forth part of a set of MCNP6 Testing Primers, after its first, LA-UR-11-05129, and second, LA-UR-11-05627, and third, LA-UR-26944, publications, but is devoted to V&V with the latest, 1.1 beta version of MCNP6. The MCNP6more » test-problems discussed here are presented in the /VALIDATION_CEM/and/VALIDATION_LAQGSM/subdirectories in the MCNP6/Testing/directory. README files that contain short descriptions of every input file, the experiment, the quantity of interest that the experiment measures and its description in the MCNP6 output files, and the publication reference of that experiment are presented for every test problem. Templates for plotting the corresponding results with xmgrace as well as pdf files with figures representing the final results of our V&V efforts are presented. Several technical “bugs” in MCNP 6.1.1 beta were discovered during our current V&V of MCNP6 while running it in parallel with MPI using its event generators. These “bugs” are to be fixed in the following version of MCNP6. Our results show that MCNP 6.1.1 beta using its CEM03.03, LAQGSM03.03, Bertini, and INCL+ABLA, event generators describes, as a rule, reasonably well different intermediate- and high-energy measured data. This primer isn’t meant to be read from cover to cover. Readers may skip some sections and go directly to any test problem in which they are interested.« less

Shaping thin film growth and microstructure pathways via plasma and deposition energy: a detailed theoretical, computational and experimental analysis.

PubMed

Sahu, Bibhuti Bhusan; Han, Jeon Geon; Kersten, Holger

2017-02-15

Understanding the science and engineering of thin films using plasma assisted deposition methods with controlled growth and microstructure is a key issue in modern nanotechnology, impacting both fundamental research and technological applications. Different plasma parameters like electrons, ions, radical species and neutrals play a critical role in nucleation and growth and the corresponding film microstructure as well as plasma-induced surface chemistry. The film microstructure is also closely associated with deposition energy which is controlled by electrons, ions, radical species and activated neutrals. The integrated studies on the fundamental physical properties that govern the plasmas seek to determine their structure and modification capabilities under specific experimental conditions. There is a requirement for identification, determination, and quantification of the surface activity of the species in the plasma. Here, we report a detailed study of hydrogenated amorphous and crystalline silicon (c-Si:H) processes to investigate the evolution of plasma parameters using a theoretical model. The deposition processes undertaken using a plasma enhanced chemical vapor deposition method are characterized by a reactive mixture of hydrogen and silane. Later, various contributions of energy fluxes on the substrate are considered and modeled to investigate their role in the growth of the microstructure of the deposited film. Numerous plasma diagnostic tools are used to compare the experimental data with the theoretical results. The film growth and microstructure are evaluated in light of deposition energy flux under different operating conditions.

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

NASA Technical Reports Server (NTRS)

Childs, Dara W.; Alexander, Chis

1994-01-01

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.

Thermomagnetic convective flows in a vertical layer of ferrocolloid: perturbation energy analysis and experimental study.

PubMed

Suslov, Sergey A; Bozhko, Alexandra A; Sidorov, Alexander S; Putin, Gennady F

2012-07-01

Flow patterns arising in a vertical differentially heated layer of nonconducting ferromagnetic fluid placed in an external uniform transverse magnetic field are studied experimentally and discussed from the point of view of the perturbation energy balance. A quantitative criterion for detecting the parametric point where the dominant role in generating a flow instability is transferred between the thermogravitational and thermomagnetic mechanisms is suggested, based on the disturbance energy balance analysis. A comprehensive experimental study of various flow patterns is undertaken, and the existence is demonstrated of oblique thermomagnetic waves theoretically predicted by Suslov [Phys. Fluids 20, 084101 (2008)] and superposed onto the stationary magnetoconvective pattern known previously. It is found that the wave number of the detected convection patterns depends sensitively on the temperature difference across the layer and on the applied magnetic field. In unsteady regimes its value varies periodically by a factor of almost 2, indicating the appearance of two different competing wave modes. The wave numbers and spatial orientation of the observed dominant flow patterns are found to be in good agreement with theoretical predictions.

An experimentally validated model for geometrically nonlinear plucking-based frequency up-conversion in energy harvesting

NASA Astrophysics Data System (ADS)

Kathpalia, B.; Tan, D.; Stern, I.; Erturk, A.

2018-01-01

It is well known that plucking-based frequency up-conversion can enhance the power output in piezoelectric energy harvesting by enabling cyclic free vibration at the fundamental bending mode of the harvester even for very low excitation frequencies. In this work, we present a geometrically nonlinear plucking-based framework for frequency up-conversion in piezoelectric energy harvesting under quasistatic excitations associated with low-frequency stimuli such as walking and similar rigid body motions. Axial shortening of the plectrum is essential to enable plucking excitation, which requires a nonlinear framework relating the plectrum parameters (e.g. overlap length between the plectrum and harvester) to the overall electrical power output. Von Kármán-type geometrically nonlinear deformation of the flexible plectrum cantilever is employed to relate the overlap length between the flexible (nonlinear) plectrum and the stiff (linear) harvester to the transverse quasistatic tip displacement of the plectrum, and thereby the tip load on the linear harvester in each plucking cycle. By combining the nonlinear plectrum mechanics and linear harvester dynamics with two-way electromechanical coupling, the electrical power output is obtained directly in terms of the overlap length. Experimental case studies and validations are presented for various overlap lengths and a set of electrical load resistance values. Further analysis results are reported regarding the combined effects of plectrum thickness and overlap length on the plucking force and harvested power output. The experimentally validated nonlinear plectrum-linear harvester framework proposed herein can be employed to design and optimize frequency up-conversion by properly choosing the plectrum parameters (geometry, material, overlap length, etc) as well as the harvester parameters.

Beta decay and the origin of biologial chirality - New experimental results

NASA Technical Reports Server (NTRS)

Van House, J.; Rich, A.; Zitzewitz, P. W.

1984-01-01

The hypothetical connection developed by Vester and Ulbricht (1959), between the handedness of beta particles in radioactive decay and the (L) sign of biologial chirality is investigated in a radiolysis experiment. The experiment measured the predicted asymmetry in the formation triplet or 'ortho-' positronium (oPs) in amino acid enantiomers by low energy positrons under conditions of helicity reversal. The positrons were focused on amino acid powder samples. By measuring the time between positron arrival and emission of gamma rays, long-lived oPs were separated from other species. It is found that the asymmetry in leucine (0.8 x 10 to the -4th) is consistent with the theoretical prediction of 10 to the -6th. Neither the experimental limits nor the theoretical estimates are found to rule out a mechanism like that described by Vester and Ulbricht as the cause of the sign of the observed chiral polarization.

Experimental Results From Stitched Composite Multi-Bay Fuselage Panels Tested Under Uni-Axial Compression

NASA Technical Reports Server (NTRS)

Baker, Donald J.

2004-01-01

The experimental results from two stitched VARTM composite panels tested under uni-axial compression loading are presented. The curved panels are divided by frames and stringers into five or six bays with a column of three bays along the compressive loading direction. The frames are supported at the ends to resist out-of-plane translation. Back-to-back strain gages are used to record the strain and displacement transducers were used to record the out-of-plane displacements. In addition a full-field measurement technique that utilizes a camera-based-stero-vision system was used to record displacements. The panels were loaded in increments to determine the first bay to buckle. Loading was discontinued at limit load and the panels were removed from the test machine for impact testing. After impacting at 20 ft-lbs to 25 ft-lbs of energy with a spherical indenter, the panels were loaded in compression until failure. Impact testing reduced the axial stiffness 4 percent and less than 1 percent. Postbuckled axial panel stiffness was 52 percent and 70 percent of the pre-buckled stiffness.

Results on the energy dependence of cosmic-ray charge composition

NASA Technical Reports Server (NTRS)

Balasubrahmanyan, V. K.; Ormes, J. F.

1973-01-01

Results of measurements by a balloon-borne ionization spectrometer of the energy dependence of high-energy cosmic-ray charge composition. The results presented are greatly improved over those obtained earlier by Ormes et al. (1971) by the use of a multidimensional charge analysis with more efficient background rejection, and a more accurate energy determination. Complex couplings between the charge, energy, and trajectory information were taken into account and are discussed. The spectra of individual elements up to oxygen and of groups of nuclei up through iron were measured up to almost 100 GeV per nucleon. The energy spectrum of the secondary nuclei, B + N, is found to be steeper than that of the primary nuclei, C + O, in agreement with Smith et al. (1973). 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 plus or minus 0.14 of a power.

Mechanism on brain information processing: Energy coding

NASA Astrophysics Data System (ADS)

Wang, Rubin; Zhang, Zhikang; Jiao, Xianfa

2006-09-01

According to the experimental result of signal transmission and neuronal energetic demands being tightly coupled to information coding in the cerebral cortex, the authors present a brand new scientific theory that offers a unique mechanism for brain information processing. They demonstrate that the neural coding produced by the activity of the brain is well described by the theory of energy coding. Due to the energy coding model's ability to reveal mechanisms of brain information processing based upon known biophysical properties, they cannot only reproduce various experimental results of neuroelectrophysiology but also quantitatively explain the recent experimental results from neuroscientists at Yale University by means of the principle of energy coding. Due to the theory of energy coding to bridge the gap between functional connections within a biological neural network and energetic consumption, they estimate that the theory has very important consequences for quantitative research of cognitive function.

Experimental Verification of a Dynamic Voltage Restorer Capable of Significantly Reducing an Energy-Storage Element

NASA Astrophysics Data System (ADS)

Jimichi, Takushi; Fujita, Hideaki; Akagi, Hirofumi

This paper deals with a dynamic voltage restorer (DVR) characterized by installing the shunt converter at the load side. The DVR can compensate for the load voltage when a voltage sag appears in the supply voltage. An existing DVR requires a large capacitor bank or other energy-storage elements such as double-layer capacitors or batteries. The DVR presented in this paper requires only a small dc capacitor intended for smoothing the dc-link voltage. Moreover, three control methods for the series converter are compared and discussed to reduce the series-converter rating, paying attention to the zero-sequence voltages included in the supply voltage and the compensating voltage. Experimental results obtained from a 200-V, 5-kW laboratory system are shown to verify the viability of the system configuration and the control methods.

At Odds: Reconciling Experimental and Theoretical Results in High School Physics

ERIC Educational Resources Information Center

Gates, Joshua

2009-01-01

For this experiment, students are divided into 2 groups and presented with a static equilibrium force-balance problem to solve. One group works entirely experimentally and the other group theoretically, using Newton's laws. The groups present their seemingly dissimilar results and must reconcile them through discussion. (Contains 3 figures.)

Resonance energy transfer: Dye to metal nanoparticles

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

Wari, M. N.; Pujar, G. H.; Inamdar, S. R., E-mail: him-lax3@yahoo.com

2015-06-24

In the present study, surface energy transfer (SET) from Coumarin 540A (C540 A) to Gold nanoparticle (Au) is demonstrated. The observed results show pronounced effect on the photoluminescence intensity and shortening of the lifetime of Coumarin 540A upon interaction with the spherical gold nanoparticle, also there are measured effects on radiative rate of the dye. Experimental results are analyzed with fluorescence resonance energy transfer (FRET) and SET theories. The results obtained from distance-dependent quenching provide experimental evidence that the efficiency curve slope and distance of quenching is best modeled by surface energy transfer process.

Phase transition kinetics in DIET of vanadium pentoxide. I. Experimental results

NASA Astrophysics Data System (ADS)

Ai, R.; Fan, H.-J.; Marks, L. D.

1993-01-01

Experimental results of the kinetics of phase transformation in vanadium pentoxide during surface loss of oxygen from electron irradiation are described. Phase transformations under three different regimes were examined: (a) low flux; (b) intermediate flux and (c) high flux. Different phase transformation routes were observed under different fluxes. In a companion paper, numerical calculations are presented demonstrating that these results are due to a mixed interface/diffusion controlled phase transition pumped by surface oxygen loss.

Modeling and experimental verification of a fan-folded vibration energy harvester for leadless pacemakers

NASA Astrophysics Data System (ADS)

Ansari, M. H.; Karami, M. Amin

2016-03-01

This paper studies energy harvesting from heartbeat vibrations for powering leadless pacemakers. Unlike traditional pacemakers, leadless pacemakers are implanted inside the heart and the pacemaker is in direct contact with the myocardium. A leadless pacemaker is in the shape of a cylinder. Thus, in order to utilize the available 3-dimensional space for the energy harvester, we choose a fan-folded 3D energy harvester. The proposed device consists of several piezoelectric beams stacked on top of each other. The volume of the energy harvester is 1 cm3 and its dimensions are 2 cm × 0.5 cm × 1 cm. Although high natural frequency is generally a major concern with micro-scale energy harvesters, by utilizing the fan-folded geometry and adding tip mass and link mass to the configuration, we reduced the natural frequency to the desired range. This fan-folded design makes it possible to generate more than 10 μ W of power per cubic centimeter. The proposed device is compatible with Magnetic Resonance Imaging. Although the proposed device is a linear energy harvester, it is relatively insensitive to the heart rate. The natural frequencies and the mode shapes of the device are calculated analytically. The accuracy of the analytical model is verified by experimental investigations. We use a closed loop shaker system to precisely replicate heartbeat vibrations in vitro.

Design and experimental results of the 1-T Bitter Electromagnet Testing Apparatus (BETA)

NASA Astrophysics Data System (ADS)

Bates, E. M.; Birmingham, W. J.; Romero-Talamás, C. A.

2018-05-01

The Bitter Electromagnet Testing Apparatus (BETA) is a 1-Tesla (T) technical prototype of the 10 T Adjustable Long Pulsed High-Field Apparatus. BETA's final design specifications are highlighted in this paper which include electromagnetic, thermal, and stress analyses. We discuss here the design and fabrication of BETA's core, vessel, cooling, and electrical subsystems. The electrical system of BETA is composed of a scalable solid-state DC breaker circuit. Experimental results display the stable operation of BETA at 1 T. These results are compared to both analytical design and finite element calculations. Experimental results validate analytical magnet designing methods developed at the Dusty Plasma Laboratory. The theoretical steady state maxima and the limits of BETA's design are explored in this paper.

Design and experimental results of the 1-T Bitter Electromagnet Testing Apparatus (BETA).

PubMed

Bates, E M; Birmingham, W J; Romero-Talamás, C A

2018-05-01

The Bitter Electromagnet Testing Apparatus (BETA) is a 1-Tesla (T) technical prototype of the 10 T Adjustable Long Pulsed High-Field Apparatus. BETA's final design specifications are highlighted in this paper which include electromagnetic, thermal, and stress analyses. We discuss here the design and fabrication of BETA's core, vessel, cooling, and electrical subsystems. The electrical system of BETA is composed of a scalable solid-state DC breaker circuit. Experimental results display the stable operation of BETA at 1 T. These results are compared to both analytical design and finite element calculations. Experimental results validate analytical magnet designing methods developed at the Dusty Plasma Laboratory. The theoretical steady state maxima and the limits of BETA's design are explored in this paper.

Photovoltaic Grid-Connected Modeling and Characterization Based on Experimental Results.

PubMed

Humada, Ali M; Hojabri, Mojgan; Sulaiman, Mohd Herwan Bin; Hamada, Hussein M; Ahmed, Mushtaq N

2016-01-01

A grid-connected photovoltaic (PV) system operates under fluctuated weather condition has been modeled and characterized based on specific test bed. A mathematical model of a small-scale PV system has been developed mainly for residential usage, and the potential results have been simulated. The proposed PV model based on three PV parameters, which are the photocurrent, IL, the reverse diode saturation current, Io, the ideality factor of diode, n. Accuracy of the proposed model and its parameters evaluated based on different benchmarks. The results showed that the proposed model fitting the experimental results with high accuracy compare to the other models, as well as the I-V characteristic curve. The results of this study can be considered valuable in terms of the installation of a grid-connected PV system in fluctuated climatic conditions.

Experimental High Energy Physics Research

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

Hohlmann, Marcus

This final report summarizes activities of the Florida Tech High Energy Physics group supported by DOE under grant #DE-SC0008024 during the period June 2012 – March 2015. We focused on one of the main HEP research thrusts at the Energy Frontier by participating in the CMS experiment. We were exploiting the tremendous physics opportunities at the Large Hadron Collider (LHC) and prepared for physics at its planned extension, the High-Luminosity LHC. The effort comprised a physics component with analysis of data from the first LHC run and contributions to the CMS Phase-2 upgrades in the muon endcap system (EMU) formore » the High-Luminosity LHC. The emphasis of our hardware work was the development of large-area Gas Electron Multipliers (GEMs) for the CMS forward muon upgrade. We built a production and testing site for such detectors at Florida Tech to complement future chamber production at CERN. The first full-scale CMS GE1/1 chamber prototype ever built outside of CERN was constructed at Florida Tech in summer 2013. We conducted two beam tests with GEM prototype chambers at CERN in 2012 and at FNAL in 2013 and reported the results at conferences and in publications. Principal Investigator Hohlmann served as chair of the collaboration board of the CMS GEM collaboration and as co-coordinator of the GEM detector working group. He edited and authored sections of the detector chapter of the Technical Design Report (TDR) for the GEM muon upgrade, which was approved by the LHCC and the CERN Research Board in 2015. During the course of the TDR approval process, the GEM project was also established as an official subsystem of the muon system by the CMS muon institution board. On the physics side, graduate student Kalakhety performed a Z' search in the dimuon channel with the 2011 and 2012 CMS datasets that utilized 20.6 fb⁻¹ of p-p collisions at √s = 8 TeV. For the dimuon channel alone, the 95% CL lower limits obtained on the mass of a Z' resonance are 2770 GeV for

From Deuterium to Free Neutrons - Recent Experimental Results

NASA Astrophysics Data System (ADS)

Kuhn, Sebastian

2009-05-01

Lepton scattering has long been used to gather data on the internal structure of both protons and neutrons. Assuming isospin symmetry, these data can be used to pin down the contributions of both u and d quarks to the spatial and momentum-spin structure of the nucleon and its excitations. In this context, information on the neutron is crucial and is typically obtained from experiments on few-body nuclear targets (predominantly ^3He and deuterium). However, the need to account for binding effects complicates the interpretation of these experiments. On the other hand, detailed studies of the reaction mechanism can yield important new information on the structure of few-body nuclei and the interplay of nuclear and quark degrees of freedom. Recent theoretical and experimental advances have allowed us to make significant progress on both fronts -- a cleaner extraction of neutron properties from nuclear data and a better understanding of nuclear modifications of the bound neutron structure. I will concentrate on recent results on the deuteron. I will present a new extraction of neutron spin structure functions in the resonance and large-x region (from the EG1 experiment with CLAS at Jefferson Lab). The same data can also be used for a detailed comparison with modern calculations of quasi-elastic spin-dependent scattering on the deuteron. A second experimental program with CLAS uses the technique of ``spectator tagging'' to extract the unpolarized structure functions of the neutron with minimal uncertainties from nuclear effects. By mapping out the dependence of the cross section on the ``spectator'' momentum, we can learn about final state interactions between the struck nucleon and the spectator, as well as modifications of the neutron structure due to nuclear binding. I will present preliminary results from the ``BoNuS'' experiment which pushed the detection limit of the spectator proton down to momenta of 70 MeV/c, where nuclear corrections should become small.

A combined theoretical and experimental approach of a new ternary metal oxide in molybdate composite for hybrid energy storage capacitors

NASA Astrophysics Data System (ADS)

Minakshi, M.; Watcharatharapong, T.; Chakraborty, S.; Ahuja, R.

2018-04-01

Sustainable energy sources require an efficient energy storage system possessing excellent electrochemical properties. The better understanding of possible crystal configurations and the development of a new ternary metal oxide in molybdate composite as an electrode for hybrid capacitors can lead to an efficient energy storage system. Here, we reported a new ternary metal oxide in molybdate composite [(Mn1/3Co1/3Ni1/3)MoO4] prepared by simple combustion synthesis with an extended voltage window (1.8 V vs. Carbon) resulting in excellent specific capacity 35 C g-1 (58 F g-1) and energy density (50 Wh kg-1 at 500 W kg-1) for a two electrode system in an aqueous NaOH electrolyte. The binding energies measured for Mn, Co, and Ni 2p are consistent with the literature, and with the metal ions being present as M(II), implying that the oxidation states of the transition metals are unchanged. The experimental findings are correlated well through density functional theory based electronic structure calculations. Our reported work on the ternary metal oxide studies (Mn1/3Co1/3Ni1/3)MoO4 suggests that will be an added value to the materials for energy storage.

Flexible energy harvesting from hard piezoelectric beams

NASA Astrophysics Data System (ADS)

Delnavaz, Aidin; Voix, Jérémie

2016-11-01

This paper presents design, multiphysics finite element modeling and experimental validation of a new miniaturized PZT generator that integrates a bulk piezoelectric ceramic onto a flexible platform for energy harvesting from the human body pressing force. In spite of its flexibility, the mechanical structure of the proposed device is simple to fabricate and efficient for the energy conversion. The finite element model involves both mechanical and piezoelectric parts of the device coupled with the electrical circuit model. The energy harvester prototype was fabricated and tested under the low frequency periodic pressing force during 10 seconds. The experimental results show that several nano joules of electrical energy is stored in a capacitor that is quite significant given the size of the device. The finite element model is validated by observing a good agreement between experimental and simulation results. the validated model could be used for optimizing the device for energy harvesting from earcanal deformations.

Physical mechanism of comet outbursts - An experimental result

NASA Technical Reports Server (NTRS)

Hartmann, William K.

1993-01-01

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.

SIDDHARTA results and implications of the results on antikaon-nucleon interaction

NASA Astrophysics Data System (ADS)

Marton, J.; Bazzi, M.; Beer, G.; Berucci, C.; Bellotti, G.; Bosnar, D.; Bragadireanu, A. M.; Cargnelli, M.; Clozza, A.; Curceanu, C.; Butt, A. Dawood; Fiorini, C.; Ghio, F.; Guaraldo, C.; Hayano, R.; Iliescu, M.; Iwasaki, M.; Sandri, P. Levi; Okada, S.; Pietreanu, D.; Piscicchia, K.; Vidal, A. Romero; Scordo, A.; Shi, H.; Sirghi, D. L.; Sirghi, F.; Tatsuno, H.; Doce, O. Vazquez; Widmann, E.; Zmeskal, J.

2016-05-01

The interaction of antikaons (K-) with nucleons and nuclei in the low-energy regime represents an active research field in hadron physics. There are important open questions like the existence of antikaon nuclear bound states like the prototype system being K- pp. Unique and rather direct experimental access to the antikaon-nucleon scattering lengths is provided by precision X-ray spectroscopy of transitions in low-lying states in light kaonic atoms like kaonic hydrogen and helium isotopes. In the SIDDHARTA experiment at the electron-positron collider DAΦNE of LNF-INFN we measured the most precise values of the strong interaction observables, i.e. the strong interaction on the 1s ground state of the electromagnetically bound K-p atom leading to energy shift and broadening of the 1s state. The SIDDHARTA result triggered new theoretical work, which achieved major progress in the understanding of the low-energy strong interaction with strangeness reflected by the antikaon-nucleon scattering lengths calculated with the K--proton amplitudes constrained by the SIDDHARTA data. The most important open question is the experimental determination of the hadronic energy shift and width of kaonic deuterium which is planned by the SIDDHARTA-2 Collaboration.

Modeling and experimental validation of a Hybridized Energy Storage System for automotive applications

NASA Astrophysics Data System (ADS)

Fiorenti, Simone; Guanetti, Jacopo; Guezennec, Yann; Onori, Simona

2013-11-01

This paper presents the development and experimental validation of a dynamic model of a Hybridized Energy Storage System (HESS) consisting of a parallel connection of a lead acid (PbA) battery and double layer capacitors (DLCs), for automotive applications. The dynamic modeling of both the PbA battery and the DLC has been tackled via the equivalent electric circuit based approach. Experimental tests are designed for identification purposes. Parameters of the PbA battery model are identified as a function of state of charge and current direction, whereas parameters of the DLC model are identified for different temperatures. A physical HESS has been assembled at the Center for Automotive Research The Ohio State University and used as a test-bench to validate the model against a typical current profile generated for Start&Stop applications. The HESS model is then integrated into a vehicle simulator to assess the effects of the battery hybridization on the vehicle fuel economy and mitigation of the battery stress.

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

NASA Technical Reports Server (NTRS)

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

2001-01-01

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.

The MIRTE Experimental Program: An Opportunity to Test Structural Materials in Various Configurations in Thermal Energy Spectrum

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

Leclaire, Nicolas; Le Dauphin, Francois-Xavier; Duhamel, Isabelle

2014-11-04

The MIRTE (Materials in Interacting and Reflecting configurations, all Thicknesses) program was established to answer the needs of criticality safety practitioners in terms of experimental validation of structural materials and to possibly contribute to nuclear data improvement, which ultimately supports reactor safety analysis as well. MIRTE took the shape of a collaboration between the AREVA and ANDRA French industrialists and a noncommercial international funding partner such as the U.S. Department of Energy. The aim of this paper is to present the configurations of the MIRTE 1 and MIRTE 2 programs and to highlight the results of the titanium experiments recentlymore » published in the International Handbook of Evaluated Criticality Safety Benchmark Experiments.« less

Analyzing Sustainable Energy Opportunities for a Small Scale Off-Grid Facility: A Case Study at Experimental Lakes Area (ELA), Ontario

NASA Astrophysics Data System (ADS)

Duggirala, Bhanu

This thesis explored the opportunities to reduce energy demand and renewable energy feasibility at an off-grid science "community" called the Experimental Lakes Area (ELA) in Ontario. Being off-grid, ELA is completely dependent on diesel and propane fuel supply for all its electrical and heating needs, which makes ELA vulnerable to fluctuating fuel prices. As a result ELA emits a large amount of greenhouse gases (GHG) for its size. Energy efficiency and renewable energy technologies can reduce energy consumption and consequently energy cost, as well as GHG. Energy efficiency was very important to ELA due to the elevated fuel costs at this remote location. Minor upgrades to lighting, equipment and building envelope were able to reduce energy costs and reduce load. Efficient energy saving measures were recommended that save on operating and maintenance costs, namely, changing to LED lights, replacing old equipment like refrigerators and downsizing of ice makers. This resulted in a 4.8% load reduction and subsequently reduced the initial capital cost for biomass by 27,000, by 49,500 for wind power and by 136,500 for solar power. Many alternative energies show promise as potential energy sources to reduce the diesel and propane consumption at ELA including wind energy, solar heating and biomass. A biomass based CHP system using the existing diesel generators as back-up has the shortest pay back period of the technologies modeled. The biomass based CHP system has a pay back period of 4.1 years at 0.80 per liter of diesel, as diesel price approaches $2.00 per liter the pay back period reduces to 0.9 years, 50% the generation cost compared to present generation costs. Biomass has been successfully tried and tested in many off-grid communities particularly in a small-scale off-grid setting in North America and internationally. Also, the site specific solar and wind data show that ELA has potential to harvest renewable resources and produce heat and power at competitive

Design and construction of a spectrometer facility and experiment for intermediate energy proton scattering on helium. [Wave functions, preliminary experimental techniques

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

Rolfe, R.M.

1976-12-01

The goal of the research was to investigate proton scattering on nuclei at intermediate energies and in particular to investigate proton scattering on helium. A theoretical investigation of the helium nucleus and the nature of the intermediate energy interaction, design and optimization of an energy-loss spectrometer facility for proton-nucleus scattering, and the unique superfluid helium target and experimental design are discussed.

Comparison of simulation results with sea-level experimental data on 10(14) - 10(16) air shower cores

NASA Technical Reports Server (NTRS)

Ash, A. G.

1985-01-01

Simulation predictions for the Leeds 35 sq m horizontal discharge chamber array for proton primaries with a approx. E sup 2.7 spectrum extrapolated from balloon data to 10 to the 16th power eV give power law rho (r)-spectra with constant slope approx. -2 consistent with the experimental data up to the point at which they steepen but overshooting them at higher densities, and at high shower sizes predicted cores which are significantly steeper than those observed. Further comparisons with results for heavy nuclei primaries (up to A = 56) point to the inadequacy of changes in primary composition to account for the observed density spectra and core flattening, and the shower size spectrum together, and point, therefore, to the failure of the scaling interaction model at approx. 10 to the 15th power eV primary energy.

Photovoltaic Grid-Connected Modeling and Characterization Based on Experimental Results

PubMed Central

Humada, Ali M.; Hojabri, Mojgan; Sulaiman, Mohd Herwan Bin; Hamada, Hussein M.; Ahmed, Mushtaq N.

2016-01-01

A grid-connected photovoltaic (PV) system operates under fluctuated weather condition has been modeled and characterized based on specific test bed. A mathematical model of a small-scale PV system has been developed mainly for residential usage, and the potential results have been simulated. The proposed PV model based on three PV parameters, which are the photocurrent, IL, the reverse diode saturation current, Io, the ideality factor of diode, n. Accuracy of the proposed model and its parameters evaluated based on different benchmarks. The results showed that the proposed model fitting the experimental results with high accuracy compare to the other models, as well as the I-V characteristic curve. The results of this study can be considered valuable in terms of the installation of a grid-connected PV system in fluctuated climatic conditions. PMID:27035575

An energy-dependent electron backscattering coefficient

NASA Astrophysics Data System (ADS)

Williamson, W., Jr.; Antolak, A. J.; Meredith, R. J.

1987-05-01

An energy-dependent electron backscattering coefficient is derived based on the continuous slowing down approximation and the Bethe stopping power. Backscattering coefficients are given for 10-50-keV electrons incident on bulk and thin-film aluminum, silver, and gold targets. The results are compared with the Everhart theory and empirical fits to experimental data. The energy-dependent theory agrees better with experimental work.

Experimental investigation of interfacial energy transport in an evaporating sessile droplet for evaporative cooling applications

NASA Astrophysics Data System (ADS)

Mahmud, Md. Almostasim; MacDonald, Brendan D.

2017-01-01

In this paper we experimentally examine evaporation flux distributions and modes of interfacial energy transport for continuously fed evaporating spherical sessile water droplets in a regime that is relevant for applications, particularly for evaporative cooling systems. The contribution of the thermal conduction through the vapor phase was found to be insignificant compared to the thermal conduction through the liquid phase for the conditions we investigated. The local evaporation flux distributions associated with thermal conduction were found to vary along the surface of the droplet. Thermal conduction provided a majority of the energy required for evaporation but did not account for all of the energy transport, contributing 64 ±3 % , 77 ±3 % , and 77 ±4 % of the energy required for the three cases we examined. Based on the temperature profiles measured along the interface we found that thermocapillary flow was predicted to occur in our experiments, and two convection cells were consistent with the temperature distributions for higher substrate temperatures while a single convection cell was consistent with the temperature distributions for a lower substrate temperature.

An experimental investigation of energy absorption in TRIP steel under impact three-point bending deformation

NASA Astrophysics Data System (ADS)

Pham, Hang; Iwamoto, Takeshi

2015-09-01

TRIP (Transformation-induced Plasticity) steel is nowadays in widespread use in the automobile industry because of their favorable mechanical properties such as high strength, excellent formability and toughness because of strain-induced martensitic transformation. Moreover, when TRIP steel is applied to the components of the vehicles, it is expected that huge amount of kinetic energy will be absorbed into both plastic deformation and martensitic transformation during the collision. Basically, bending deformation due to buckling is one of the major crash deformation modes of automobile structures. Thus, an investigation of energy absorption during bending deformation at high impact velocity for TRIP steel is indispensable. Although TRIP steel have particularly attracted the recent interest of the scientific community, just few studies can be found on the energy absorption characteristic of TRIP steel, especially at impact loading condition. In present study, experimental investigations of bending deformation behaviors of TRIP steel are conducted in the three-point bending tests for both smooth and pre-cracked specimen. Then, energy absorption characteristic during plastic deformation and fracture process at high impact velocity in TRIP steel will be discussed.

Energy Conversion Loop: A Testbed for Nuclear Hybrid Energy Systems Use in Biomass Pyrolysis

NASA Astrophysics Data System (ADS)

Verner, Kelley M.

Nuclear hybrid energy systems are a possible solution for contemporary energy challenges. Nuclear energy produces electricity without greenhouse gas emissions. However, nuclear power production is not as flexible as electrical grids demand and renewables create highly variable electricity. Nuclear hybrid energy systems are able to address both of these problems. Wasted heat can be used in processes such as desalination, hydrogen production, or biofuel production. This research explores the possible uses of nuclear process heat in bio-oil production via biomass pyrolysis. The energy conversion loop is a testbed designed and built to mimic the heat from a nuclear reactor. Small scale biomass pyrolysis experiments were performed and compared to results from the energy conversion loop tests to determine future pyrolysis experimentation with the energy conversion loop. Further improvements must be made to the energy conversion loop before more complex experiments may be performed. The current conditions produced by the energy conversion loop are not conducive for current biomass pyrolysis experimentation.tion.

Experimental results for characterization of a tapered plastic optical fiber sensor based on SPR

NASA Astrophysics Data System (ADS)

Cennamo, N.; Galatus, R.; Zeni, L.

2015-05-01

The experimental results obtained with two different Plastic Optical Fiber (POF) geometries, tapered and not-tapered, for a sensor based on Surface Plasmon Resonance (SPR) are presented. SPR is used for determining the refractive index variations at the interface between a gold layer and a dielectric medium (aqueous medium). In this work SPR sensors in POF configurations, useful for bio-sensing applications, have been realized for the optimization of the sensitivity and experimentally tested. The results show as the sensitivity increases with the tapered POF configuration, when the refractive index of aqueous medium increases.

Dynamic modeling, experimental evaluation, optimal design and control of integrated fuel cell system and hybrid energy systems for building demands

NASA Astrophysics Data System (ADS)

Nguyen, Gia Luong Huu

Fuel cells can produce electricity with high efficiency, low pollutants, and low noise. With the advent of fuel cell technologies, fuel cell systems have since been demonstrated as reliable power generators with power outputs from a few watts to a few megawatts. With proper equipment, fuel cell systems can produce heating and cooling, thus increased its overall efficiency. To increase the acceptance from electrical utilities and building owners, fuel cell systems must operate more dynamically and integrate well with renewable energy resources. This research studies the dynamic performance of fuel cells and the integration of fuel cells with other equipment in three levels: (i) the fuel cell stack operating on hydrogen and reformate gases, (ii) the fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit, and (iii) the hybrid energy system consisting of photovoltaic panels, fuel cell system, and energy storage. In the first part, this research studied the steady-state and dynamic performance of a high temperature PEM fuel cell stack. Collaborators at Aalborg University (Aalborg, Denmark) conducted experiments on a high temperature PEM fuel cell short stack at steady-state and transients. Along with the experimental activities, this research developed a first-principles dynamic model of a fuel cell stack. The dynamic model developed in this research was compared to the experimental results when operating on different reformate concentrations. Finally, the dynamic performance of the fuel cell stack for a rapid increase and rapid decrease in power was evaluated. The dynamic model well predicted the performance of the well-performing cells in the experimental fuel cell stack. The second part of the research studied the dynamic response of a high temperature PEM fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit with high thermal integration. After verifying the model performance with the

Experimental and Monte Carlo studies of fluence corrections for graphite calorimetry in low- and high-energy clinical proton beams.

PubMed

Lourenço, Ana; Thomas, Russell; Bouchard, Hugo; Kacperek, Andrzej; Vondracek, Vladimir; Royle, Gary; Palmans, Hugo

2016-07-01

The aim of this study was to determine fluence corrections necessary to convert absorbed dose to graphite, measured by graphite calorimetry, to absorbed dose to water. Fluence corrections were obtained from experiments and Monte Carlo simulations in low- and high-energy proton beams. Fluence corrections were calculated to account for the difference in fluence between water and graphite at equivalent depths. Measurements were performed with narrow proton beams. Plane-parallel-plate ionization chambers with a large collecting area compared to the beam diameter were used to intercept the whole beam. High- and low-energy proton beams were provided by a scanning and double scattering delivery system, respectively. A mathematical formalism was established to relate fluence corrections derived from Monte Carlo simulations, using the fluka code [A. Ferrari et al., "fluka: A multi-particle transport code," in CERN 2005-10, INFN/TC 05/11, SLAC-R-773 (2005) and T. T. Böhlen et al., "The fluka Code: Developments and challenges for high energy and medical applications," Nucl. Data Sheets 120, 211-214 (2014)], to partial fluence corrections measured experimentally. A good agreement was found between the partial fluence corrections derived by Monte Carlo simulations and those determined experimentally. For a high-energy beam of 180 MeV, the fluence corrections from Monte Carlo simulations were found to increase from 0.99 to 1.04 with depth. In the case of a low-energy beam of 60 MeV, the magnitude of fluence corrections was approximately 0.99 at all depths when calculated in the sensitive area of the chamber used in the experiments. Fluence correction calculations were also performed for a larger area and found to increase from 0.99 at the surface to 1.01 at greater depths. Fluence corrections obtained experimentally are partial fluence corrections because they account for differences in the primary and part of the secondary particle fluence. A correction factor, F(d), has been

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

NASA Technical Reports Server (NTRS)

Goldhirsh, Julius; Vogel, Wolfhard J.

1992-01-01

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.

Experimental and computational results on exciton/free-carrier ratio, hot/thermalized carrier diffusion, and linear/nonlinear rate constants affecting scintillator proportionality

NASA Astrophysics Data System (ADS)

Williams, R. T.; Grim, Joel Q.; Li, Qi; Ucer, K. B.; Bizarri, G. A.; Kerisit, S.; Gao, Fei; Bhattacharya, P.; Tupitsyn, E.; Rowe, E.; Buliga, V. M.; Burger, A.

2013-09-01

Models of nonproportional response in scintillators have highlighted the importance of parameters such as branching ratios, carrier thermalization times, diffusion, kinetic order of quenching, associated rate constants, and radius of the electron track. For example, the fraction ηeh of excitations that are free carriers versus excitons was shown by Payne and coworkers to have strong correlation with the shape of electron energy response curves from Compton-coincidence studies. Rate constants for nonlinear quenching are implicit in almost all models of nonproportionality, and some assumption about track radius must invariably be made if one is to relate linear energy deposition dE/dx to volume-based excitation density n (eh/cm3) in terms of which the rates are defined. Diffusion, affecting time-dependent track radius and thus density of excitations, has been implicated as an important factor in nonlinear light yield. Several groups have recently highlighted diffusion of hot electrons in addition to thermalized carriers and excitons in scintillators. However, experimental determination of many of these parameters in the insulating crystals used as scintillators has seemed difficult. Subpicosecond laser techniques including interband z scan light yield, fluence-dependent decay time, and transient optical absorption are now yielding experimental values for some of the missing rates and ratios needed for modeling scintillator response. First principles calculations and Monte Carlo simulations can fill in additional parameters still unavailable from experiment. As a result, quantitative modeling of scintillator electron energy response from independently determined material parameters is becoming possible on an increasingly firmer data base. This paper describes recent laser experiments, calculations, and numerical modeling of scintillator response.

Experimental and computational results on exciton/free-carrier ratio, hot/thermalized carrier diffusion, and linear/nonlinear rate constants affecting scintillator proportionality

DOE PAGES

Williams, R. T.; Grim, Joel Q.; Li, Qi; ...

2013-09-26

Models of nonproportional response in scintillators have highlighted the importance of parameters such as branching ratios, carrier thermalization times, diffusion, kinetic order of quenching, associated rate constants, and radius of the electron track. For example, the fraction ηeh of excitations that are free carriers versus excitons was shown by Payne and coworkers to have strong correlation with the shape of electron energy response curves from Compton-coincidence studies. Rate constants for nonlinear quenching are implicit in almost all models of nonproportionality, and some assumption about track radius must invariably be made if one is to relate linear energy deposition dE/dx tomore » volume-based excitation density n (eh/cm 3) in terms of which the rates are defined. Diffusion, affecting time-dependent track radius and thus density of excitations, has been implicated as an important factor in nonlinear light yield. Several groups have recently highlighted diffusion of hot electrons in addition to thermalized carriers and excitons in scintillators. However, experimental determination of many of these parameters in the insulating crystals used as scintillators has seemed difficult. Subpicosecond laser techniques including interband z scan light yield, fluence-dependent decay time, and transient optical absorption are now yielding experimental values for some of the missing rates and ratios needed for modeling scintillator response. First principles calculations and Monte Carlo simulations can fill in additional parameters still unavailable from experiment. As a result, quantitative modeling of scintillator electron energy response from independently determined material parameters is becoming possible on an increasingly firmer data base. This study describes recent laser experiments, calculations, and numerical modeling of scintillator response.« less

Ball milling: An experimental support to the energy transfer evaluated by the collision model

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

Magini, M.; Iasonna, A.; Padella, F.

1996-01-01

In recent years several attempts have been made in order to understand the fundamentals of the ball milling process. The aim of these approaches is to establish predictive capabilities for this process, i.e. the possibility of obtaining a given product by suitable choosing the proper milling conditions. Maurice and Courtney have modeled ball milling in a planetary and in a vibratory mill including parameters like impact times, areas of the colliding surfaces (derived from hertzian collision theory), powder strain rates and pressure peak during collision. Burgio et al derived the kinematic equations of a ball moving on a planetary millmore » and the consequent ball-to-powder energy transfer occurring in a single collision event. The fraction of input energy transferred to the powder was subsequently estimated by an analysis of the collision event. Finally an energy map was constructed which was the basis for a model with predictive capabilities. The aim of the present article is to show that the arguments used to construct the model of the milling process has substantial experimental support.« less

Experimental Results for Titan Aerobot Thermo-Mechanical Subsystem Development

NASA Technical Reports Server (NTRS)

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

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.

Experimental measurement of binding energy, selectivity, and allostery using fluctuation theorems.

PubMed

Camunas-Soler, Joan; Alemany, Anna; Ritort, Felix

2017-01-27

Thermodynamic bulk measurements of binding reactions rely on the validity of the law of mass action and the assumption of a dilute solution. Yet, important biological systems such as allosteric ligand-receptor binding, macromolecular crowding, or misfolded molecules may not follow these assumptions and may require a particular reaction model. Here we introduce a fluctuation theorem for ligand binding and an experimental approach using single-molecule force spectroscopy to determine binding energies, selectivity, and allostery of nucleic acids and peptides in a model-independent fashion. A similar approach could be used for proteins. This work extends the use of fluctuation theorems beyond unimolecular folding reactions, bridging the thermodynamics of small systems and the basic laws of chemical equilibrium. Copyright © 2017, American Association for the Advancement of Science.

Assessing Internet energy intensity: A review of methods and results

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

Coroama, Vlad C., E-mail: vcoroama@gmail.com; Hilty, Lorenz M.; Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstr. 5, 9014 St. Gallen

Assessing the average energy intensity of Internet transmissions is a complex task that has been a controversial subject of discussion. Estimates published over the last decade diverge by up to four orders of magnitude — from 0.0064 kilowatt-hours per gigabyte (kWh/GB) to 136 kWh/GB. This article presents a review of the methodological approaches used so far in such assessments: i) top–down analyses based on estimates of the overall Internet energy consumption and the overall Internet traffic, whereby average energy intensity is calculated by dividing energy by traffic for a given period of time, ii) model-based approaches that model all componentsmore » needed to sustain an amount of Internet traffic, and iii) bottom–up approaches based on case studies and generalization of the results. Our analysis of the existing studies shows that the large spread of results is mainly caused by two factors: a) the year of reference of the analysis, which has significant influence due to efficiency gains in electronic equipment, and b) whether end devices such as personal computers or servers are included within the system boundary or not. For an overall assessment of the energy needed to perform a specific task involving the Internet, it is necessary to account for the types of end devices needed for the task, while the energy needed for data transmission can be added based on a generic estimate of Internet energy intensity for a given year. Separating the Internet as a data transmission system from the end devices leads to more accurate models and to results that are more informative for decision makers, because end devices and the networking equipment of the Internet usually belong to different spheres of control. -- Highlights: • Assessments of the energy intensity of the Internet differ by a factor of 20,000. • We review top–down, model-based, and bottom–up estimates from literature. • Main divergence factors are the year studied and the inclusion of end

The impact of experimentally elevated energy expenditure on oxidative stress and lifespan in the short-tailed field vole Microtus agrestis

PubMed Central

Selman, Colin; McLaren, Jane S; Collins, Andrew R; Duthie, Garry G; Speakman, John R

2008-01-01

Life-history theory assumes that animal life histories are a consequence of trade-offs between current activities and future reproductive performance or survival, because resource supply is limited. Empirical evidence for such trade-offs in the wild are common, yet investigations of the underlying mechanisms are rare. Life-history trade-offs may have both physiological and ecological mediated costs. One hypothesized physiological mechanism is that elevated energy metabolism may increase reactive oxygen species production, leading to somatic damage and thus compromising future survival. We investigated the impact of experimentally elevated energy expenditure on oxidative damage, protection and lifespan in short-tailed field voles (Microtus agrestis) maintained in captivity to remove any confounding ecological factor effects. Energy expenditure was elevated via lifelong cold exposure (7±2°C), relative to siblings in the warm (22±2°C). No treatment effect on cumulative mortality risk was observed, with negligible effects on oxidative stress and antioxidant protection. These data suggest that in captive animals physiologically mediated costs on life history do not result from increased energy expenditure and consequent elevations in oxidative stress and reduced survival. PMID:18467297

Short-term overeating results in incomplete energy intake compensation regardless of energy density or macronutrient composition

PubMed Central

Apolzan, John W.; Bray, George A.; Hamilton, Marc T.; Zderic, Theodore W.; Han, Hongmei; Champagne, Catherine M.; Shepard, Desti; Martin, Corby K.

2013-01-01

Objective To evaluate the effects of overeating (140% of energy requirements) a high-fat low-energy density diet (HF/LED, 1.05kcal/g), high-fat high-energy density diet (HF/HED, 1.60kcal/g), and high-carbohydrate (HC) LED (1.05kcal/g) for 2-days on subsequent 4-day energy intake (EI), activity levels, appetite, and mood. Design and Methods Using a randomized cross-over design, energy expenditure and EI were standardized during overeating. Results In 20 adults with a mean±SD BMI of 30.7±4.6kg/m2, EI was not suppressed until the second day after overeating and accounted for ~30% of the excess EI. Reductions in EI did not differ among the 3 diets or across days. Overeating had no effect on subsequent energy expenditure but steps/day decreased after the HC/LED and HF/HED. Sleep time was increased after the HF/HED compared to both LEDs. After overeating a HF/HED vs. HF/LED, carbohydrate cravings, hunger, prospective food consumption, and sadness increased and satisfaction, relaxation, and tranquility decreased. Conclusions Diet type, time, or their interaction had no impact on compensation over 4 days. No adaptive thermogenesis was observed. The HF/HED vs. HF/LED had detrimental effects on food cravings, appetite, and mood. These results suggest short-term overeating is associated with incomplete compensation. PMID:23913807

Electron emission from surfaces resulting from low energy positron bombardment

NASA Astrophysics Data System (ADS)

Mukherjee, Saurabh

Measurements of the secondary electron energy spectra resulting from very low energy positron bombardment of a polycrystalline Au and Cu (100) surfaces are presented that provide evidence for a single step transition from an unbound scattering state to an image potential bound state. The primary positron energy threshold for secondary electron emission and energy cutoff of the positron induced secondary electron energy peak are consistent with an Auger like process in which an incident positron make a transition from a scattering state to a surface-image potential bound while transferring all of the energy difference to an outgoing secondary electron. We term this process: the Auger mediated quantum sticking effect (AQSE). The intensities of the positron induced secondary electron peak are used to estimate the probability of this process as a function of incident positron energy. Positron annihilation induced Auger spectra (PAES) of Cu and Au are presented that are free of all primary beam induced secondary electron background. This background was eliminated by setting the positron beam energy below AQSE threshold. The background free PAES spectra obtained include the first measurements of the low energy tail of CVV Auger transitions all the way down to zero kinetic energy. The integrated intensity of this tail is several times larger than Auger peak itself which provides strong evidence for multi-electron Auger processes.

Influence of photon beam energy on the dose enhancement factor caused by gold and silver nanoparticles: An experimental approach

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

Guidelli, Eder José, E-mail: ederguidelli@pg.ffclrp.usp.br; Baffa, Oswaldo

Purpose: Noble metal nanoparticles have found several medical applications in the areas of radiation detection; x-ray contrast agents and cancer radiation therapy. Based on computational methods, many papers have reported the nanoparticle effect on the dose deposition in the surrounding medium. Here the authors report experimental results on how silver and gold nanoparticles affect the dose deposition in alanine dosimeters containing several concentrations of silver and gold nanoparticles, for five different beam energies, using electron spin resonance spectroscopy (ESR). Methods: The authors produced alanine dosimeters containing several mass percentage of silver and gold nanoparticles. Nanoparticle sizes were measured by dynamicmore » light scattering and by transmission electron microscopy. The authors determined the dose enhancement factor (DEF) theoretically, using a widely accepted method, and experimentally, using ESR spectroscopy. Results: The DEF is governed by nanoparticle concentration, size, and position in the alanine matrix. Samples containing gold nanoparticles afford a DEF higher than 1.0, because gold nanoparticle size is homogeneous for all gold concentrations utilized. For samples containing silver particles, the silver mass percentage governs the nanoparticles size, which, in turns, modifies nanoparticle position in the alanine dosimeters. In this sense, DEF decreases for dosimeters containing large and segregated particles. The influence of nanoparticle size-position is more noticeable for dosimeters irradiated with higher beam energies, and dosimeters containing large and segregated particles become less sensitive than pure alanine (DEF < 1). Conclusions: ESR dosimetry gives the DEF in a medium containing metal nanoparticles, although particle concentration, size, and position are closely related in the system. Because this is also the case as in many real systems of materials containing inorganic nanoparticles, ESR is a valuable tool for

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

NASA Astrophysics Data System (ADS)

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

2005-05-01

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.

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

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

Menapace, E.; Birattari, C.; Bonardi, M.L.

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 inmore » 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.« less

Properties of Energy Spectra of Molecular Crystals Investigated by Nonlinear Theory

NASA Astrophysics Data System (ADS)

Pang, Xiao-Feng; Zhang, Huai-Wu

We calculate the quantum energy spectra of molecular crystals, such as acetanilide, by using discrete nonlinear Schrodinger equation, containing various interactions, appropriate to the systems. The energy spectra consist of many energy bands, in each energy band there are a lot of energy levels including some higher excited states. The result of energy spectrum is basically consistent with experimental values obtained by infrared absorption and Raman scattering in acetanilide and can also explain some experimental results obtained by Careri et al. Finally, we further discuss the influences of variously characteristic parameters on the energy spectra of the systems.

Experimental Results of Integrated Refrigeration and Storage System Testing

NASA Technical Reports Server (NTRS)

Notardonato, W. U.; Johnson, W. L.; Jumper, K.

2009-01-01

Launch operations engineers at the Kennedy Space Center have identified an Integrated Refrigeration and Storage system as a promising technology to reduce launch costs and enable advanced cryogenic operations. This system uses a close cycle Brayton refrigerator to remove energy from the stored cryogenic propellant. This allows for the potential of a zero loss storage and transfer system, as well and control of the state of the propellant through densification or re-liquefaction. However, the behavior of the fluid in this type of system is different than typical cryogenic behavior, and there will be a learning curve associated with its use. A 400 liter research cryostat has been designed, fabricated and delivered to KSC to test the thermo fluid behavior of liquid oxygen as energy is removed from the cryogen by a simulated DC cycle cryocooler. Results of the initial testing phase focusing on heat exchanger characterization and zero loss storage operations using liquid oxygen are presented in this paper. Future plans for testing of oxygen densification tests and oxygen liquefaction tests will also be discussed. KEYWORDS: Liquid Oxygen, Refrigeration, Storage

Results of an Experimental Exploration of Advanced Automated Geospatial Tools: Agility in Complex Planning

DTIC Science & Technology

2009-06-01

AUTOMATED GEOSPATIAL TOOLS : AGILITY IN COMPLEX PLANNING Primary Topic: Track 5 – Experimentation and Analysis Walter A. Powell [STUDENT] - GMU...TITLE AND SUBTITLE Results of an Experimental Exploration of Advanced Automated Geospatial Tools : Agility in Complex Planning 5a. CONTRACT NUMBER...Std Z39-18 Abstract Typically, the development of tools and systems for the military is requirement driven; systems are developed to meet

Medical waste to energy: experimental study.

PubMed

Arcuri, C; Luciani, F; Piva, P; Bartuli, F N; Ottria, L; Mecheri, B; Licoccia, S

2013-04-01

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. 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. 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. 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.

An approach to an analysis of the energy response of LiF-TLD to high energy electrons.

PubMed

Shiragai, A

1977-05-01

Responses of LiF-TLD to high energy electrons relative to 60Co gamma-rays were investigated experimentally and theoretically. The Burlin et al. theory, its modified version by Almond and McCray and the Holt et al. semi-empirical theory were examined in comparison with each experiment. An approximate approach to theoretical analysis of energy response of LiF-TLD was attempted and compared with some experimental results.

Synthesis of radiolabelled aryl azides from diazonium salts: experimental and computational results permit the identification of the preferred mechanism.

PubMed

Joshi, Sameer M; de Cózar, Abel; Gómez-Vallejo, Vanessa; Koziorowski, Jacek; Llop, Jordi; Cossío, Fernando P

2015-05-28

Experimental and computational studies on the formation of aryl azides from the corresponding diazonium salts support a stepwise mechanism via acyclic zwitterionic intermediates. The low energy barriers associated with both transition structures are compatible with very fast and efficient processes, thus making this method suitable for the chemical synthesis of radiolabelled aryl azides.

Energy saving by using natural energy from the shallow ground depths - many years operating results

NASA Astrophysics Data System (ADS)

Besler, Maciej; Skrzycki, Maciej; Cepiński, Wojciech

2017-11-01

We pay back more and more larger attention on solutions which saving energy produced from conventional fuels. This is possible to obtainment in significant quantities in fields in which use up the large quantities of energy. The formation the microclimate of interiors is an example of such situation. Especially in the case air conditioning, heating and mechanical ventilation. There is, however, a possibility of energy saving as well as considerable reducing the pollution coming from combustion of raw materials by utilising the natural renewable energy from the shallow ground. In the paper the results gained during several year of continuous measurement on the exchanger were presented. In summer periods an air cooling occurs 10-12 K, e. g. from +30 °C to +20 °C. In winter on the other hand, a preparatory preheating of the air is possible, e.g. from-18°C to about ± 0°C. It is then possible to obtain for the air conditioning system the total energy needed for cooling purposes at the summer periods, or up to 50% of the ventilation heat energy in winter picks.

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

NASA Technical Reports Server (NTRS)

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

2006-01-01

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.

Investigation of superelastic electron scattering by laser-excited Ba - Experimental procedures and results

NASA Technical Reports Server (NTRS)

Register, D. F.; Trajmar, S.; Fineman, M. A.; Poe, R. T.; Csanak, G.; Jensen, S. W.

1983-01-01

Differential (in angle) electron scattering experiments on laser-excited Ba-138 1P were carried out at 30- and 100-eV impact energies. The laser light was linearly polarized and located in the scattering plane. The superelastic scattering signal was measured as a function of polarization direction of the laser light with respect to the scattering plane. It was found at low electron scattering angles that the superelastic scattering signal was asymmetric to reflection of the polarization vector with respect to the scattering plane. This is in contradiction with theoretical predictions. An attempt was made to pinpoint the reason for this observation, and a detailed investigation of the influence of experimental conditions on the superelastic scattering was undertaken. No explanation for the asymmetry has as yet been found.

Theoretical modeling and experimental validation of a torsional piezoelectric vibration energy harvesting system

NASA Astrophysics Data System (ADS)

Qian, Feng; Zhou, Wanlu; Kaluvan, Suresh; Zhang, Haifeng; Zuo, Lei

2018-04-01

Vibration energy harvesting has been extensively studied in recent years to explore a continuous power source for sensor networks and low-power electronics. Torsional vibration widely exists in mechanical engineering; however, it has not yet been well exploited for energy harvesting. This paper presents a theoretical model and an experimental validation of a torsional vibration energy harvesting system comprised of a shaft and a shear mode piezoelectric transducer. The piezoelectric transducer position on the surface of the shaft is parameterized by two variables that are optimized to obtain the maximum power output. The piezoelectric transducer can work in d 15 mode (pure shear mode), coupled mode of d 31 and d 33, and coupled mode of d 33, d 31 and d 15, respectively, when attached at different angles. Approximate expressions of voltage and power are derived from the theoretical model, which gave predictions in good agreement with analytical solutions. Physical interpretations on the implicit relationship between the power output and the position parameters of the piezoelectric transducer is given based on the derived approximate expression. The optimal position and angle of the piezoelectric transducer is determined, in which case, the transducer works in the coupled mode of d 15, d 31 and d 33.

Experimental Plan for EDF Energy Creep Rabbit Graphite Irradiations- Rev. 2 (replaces Rev. 0 ORNL/TM/2013/49).

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

Burchell, Timothy D

2014-07-01

The experimental results obtained here will assist in the development and validation of future models of irradiation induced creep of graphite by providing the following data: Inert creep stain data from low to lifetime AGR fluence Inert creep-property data (especially CTE) from low to lifetime AGR fluence Effect of oxidation on creep modulus (by indirect comparison with experiment 1 and direct comparison with experiment 3 NB. Experiment 1 and 3 are not covered here) Data to develop a mechanistic understanding, including oAppropriate creep modulus (including pinning and high dose effects on structure) oInvestigation of CTE-creep strain behavior under inert conditionsmore » oInformation on the effect of applied stress/creep strain on crystallite orientation (requires XRD) oEffect of creep strain on micro-porosity (requires tomography & microscopy) This document describes the experimental work planned to meet the requirements of project technical specification [1] and EDF Energy requests for additional Pre-IE work. The PIE work is described in detail in this revision (Section 8 and 9).« less

Experimental measure of retinal impact force resulting from intraocular foreign body dropped onto retina through media of differing viscosity.

PubMed

Ernst, Benjamin J; Velez-Montoya, Raul; Kujundzic, Damir; Kujundzic, Elmira; Olson, Jeffrey L

2013-07-01

To evaluate and compare the perfluorocarbon liquid, silicone oil, and viscoelastic against standard saline, in their ability to dampen the impact force of a foreign body, dropped within the eye. In an experimental surgical model in where cohesive and adhesive forces of the substances are not enough to float heavy-than-water foreign bodies. A model of ophthalmic surgery was constructed. A BB pellet was dropped from 24 mm onto a force transducer through four different fluids: balanced salt solution, perfluoro-n-octane, viscoelastic, and silicone oil. The impact energy (force) for each case was measured and recorded by the force transducer. The mean force of impact for each fluid was compared using the Student t-test. Silicone oil resulted in the lowest force of impact. Both silicone oil and viscoelastic dampened the impact an order of magnitude more than perfluoro-n-octane and balanced salt solution. Silicone oil and viscoelastic cushioned the force from a dropped BB. They may be useful adjuncts to prevent iatrogenic retinal injury during vitrectomy for intraocular foreign body removal. © 2012 The Authors. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.

Biomechanical pulping of aspen chips; Energy savings resulting from different fungal treatments

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

Leatham, G.F.; Myers, G.C.; Wegner, T.H.

1990-05-01

Besides increasing paper strength, fungal treatments can also reduce the electrical energy needed for fiberizing chips during mechanical pulping. Fungal species, chip movement, and treatment duration affected the extent of energy savings. This paper reports that four-week-long treatment with white-rot fungi, including Phlebia species or Pholiota mutabilis, in a stationary wire tray bioreactor resulted in at least 35% energy savings for pulping chips to 100 mL CSF in a 300-mm-diameter disc refiner. With Phanerochaete chrysosporium in a rotating-drum bioreactor, the optimal treatment duration was four weeks. Treatment with a brown-rot fungus also resulted in energy savings. Over the range ofmore » fungi and conditions tested, neither chip weight loss nor lignin loss correlated with energy savings. Some treatments giving the least chip weight loss ({lt}5%) saved the most energy. Wood modifications responsible for energy savings differed from those that increased strength. Treatments that saved the most energy did not necessarily give the highest strength properties.« less

Internal wave emission from baroclinic jets: experimental results

NASA Astrophysics Data System (ADS)

Borcia, Ion D.; Rodda, Costanza; Harlander, Uwe

2016-04-01

Large-scale balanced flows can spontaneously radiate meso-scale inertia-gravity waves (IGWs) and are thus in fact unbalanced. While flow-dependent parameterizations for the radiation of IGWs from orographic and convective sources do exist, the situation is less developed for spontaneously emitted IGWs. Observations identify increased IGW activity in the vicinity of jet exit regions. A direct interpretation of those based on geostrophic adjustment might be tempting. However, directly applying this concept to the parameterization of spontaneous imbalance is difficult since the dynamics itself is continuously re-establishing an unbalanced flow which then sheds imbalances by GW radiation. Examining spontaneous IGW emission in the atmosphere and validating parameterization schemes confronts the scientist with particular challenges. Due to its extreme complexity, GW emission will always be embedded in the interaction of a multitude of interdependent processes, many of which are hardly detectable from analysis or campaign data. The benefits of repeated and more detailed measurements, while representing the only source of information about the real atmosphere, are limited by the non-repeatability of an atmospheric situation. The same event never occurs twice. This argues for complementary laboratory experiments, which can provide a more focused dialogue between experiment and theory. Indeed, life cycles are also examined in rotating-annulus laboratory experiments. Thus, these experiments might form a useful empirical benchmark for theoretical and modeling work that is also independent of any sort of subgrid model. In addition, the more direct correspondence between experimental and model data and the data reproducibility makes lab experiments a powerful testbed for parameterizations. Here we show first results from a small rotating annulus experiments and we will further present our new experimental facility to study wave emission from jets and fronts.

Electromagnetic Vortex-Based Radar Imaging Using a Single Receiving Antenna: Theory and Experimental Results

PubMed Central

Yuan, Tiezhu; Wang, Hongqiang; Cheng, Yongqiang; Qin, Yuliang

2017-01-01

Radar imaging based on electromagnetic vortex can achieve azimuth resolution without relative motion. The present paper investigates this imaging technique with the use of a single receiving antenna through theoretical analysis and experimental results. Compared with the use of multiple receiving antennas, the echoes from a single receiver cannot be used directly for image reconstruction using Fourier method. The reason is revealed by using the point spread function. An additional phase is compensated for each mode before imaging process based on the array parameters and the elevation of the targets. A proof-of-concept imaging system based on a circular phased array is created, and imaging experiments of corner-reflector targets are performed in an anechoic chamber. The azimuthal image is reconstructed by the use of Fourier transform and spectral estimation methods. The azimuth resolution of the two methods is analyzed and compared through experimental data. The experimental results verify the principle of azimuth resolution and the proposed phase compensation method. PMID:28335487

Integrating experimental and numerical methods for a scenario-based quantitative assessment of subsurface energy storage options

NASA Astrophysics Data System (ADS)

Kabuth, Alina; Dahmke, Andreas; Hagrey, Said Attia al; Berta, Márton; Dörr, Cordula; Koproch, Nicolas; Köber, Ralf; Köhn, Daniel; Nolde, Michael; Tilmann Pfeiffer, Wolf; Popp, Steffi; Schwanebeck, Malte; Bauer, Sebastian

2016-04-01

Within the framework of the transition to renewable energy sources ("Energiewende"), the German government defined the target of producing 60 % of the final energy consumption from renewable energy sources by the year 2050. However, renewable energies are subject to natural fluctuations. Energy storage can help to buffer the resulting time shifts between production and demand. Subsurface geological structures provide large potential capacities for energy stored in the form of heat or gas on daily to seasonal time scales. In order to explore this potential sustainably, the possible induced effects of energy storage operations have to be quantified for both specified normal operation and events of failure. The ANGUS+ project therefore integrates experimental laboratory studies with numerical approaches to assess subsurface energy storage scenarios and monitoring methods. Subsurface storage options for gas, i.e. hydrogen, synthetic methane and compressed air in salt caverns or porous structures, as well as subsurface heat storage are investigated with respect to site prerequisites, storage dimensions, induced effects, monitoring methods and integration into spatial planning schemes. The conceptual interdisciplinary approach of the ANGUS+ project towards the integration of subsurface energy storage into a sustainable subsurface planning scheme is presented here, and this approach is then demonstrated using the examples of two selected energy storage options: Firstly, the option of seasonal heat storage in a shallow aquifer is presented. Coupled thermal and hydraulic processes induced by periodic heat injection and extraction were simulated in the open-source numerical modelling package OpenGeoSys. Situations of specified normal operation as well as cases of failure in operational storage with leaking heat transfer fluid are considered. Bench-scale experiments provided parameterisations of temperature dependent changes in shallow groundwater hydrogeochemistry. As a

An Overview of NSTX Research Facility and Recent Experimental Results

NASA Astrophysics Data System (ADS)

Ono, Masayuki

2006-10-01

The 2006 NSTX experimental campaign yielded significant new experimental results in many areas. Improved plasma control achieved the highest elongation of 2.9 and plasma shape factor q95Ip/aBT = 42 MA/m.T. Active feedback correction of error fields sustained the plasma rotation and increased the pulse length of high beta discharges. Active feedback stabilization of the resistive wall mode in high-beta, low-rotation plasmas was demonstrated for ˜100 resistive wall times. Operation at higher toroidal field showed favorable plasma confinement and HHFW heating efficiency trends with the field. A broader current profile, measured by the 12-channel MSE diagnostic in high beta discharges revealed an outward anomalous diffusivity of energetic ions due to the n=1 MHD modes. A tangential microwave scattering diagnostic measured localized electron gyro-scale fluctuations in L-mode, H-mode and reversed-shear plasmas. Evaporation of lithium onto plasma facing surfaces yielded lower density, higher temperature and improved confinement. A strong dependence of the divertor heat load and ELM behavior on the plasma triangularity was observed. Coaxial helicity injection produced a start-up current of 160 kA on closed flux surfaces.

Experimental and thermodynamic study of Co-Fe and Mn-Fe based mixed metal oxides for thermochemical energy storage application

NASA Astrophysics Data System (ADS)

André, Laurie; Abanades, Stéphane; Cassayre, Laurent

2017-06-01

Metal oxides are potential materials for thermochemical heat storage, and among them, cobalt oxide and manganese oxide are attracting attention. Furthermore, studies on mixed oxides are ongoing, as the synthesis of mixed oxides could be a way to answer the drawbacks of pure metal oxides, such as slow reaction kinetics, loss-in-capacity over cycles or sintering, selected for thermochemical heat storage application. The addition of iron oxide is under investigation and the obtained results are presented. This work proposes a comparison of thermodynamic modelling with experimental data in order to identify the impact of iron oxide addition to cobalt oxide and manganese oxide. Fe addition decreased the redox activity and energy storage capacity of Co3O4, whereas the cycling stability of Mn2O3 was significantly improved with added Fe amounts above 20 mol% while the energy storage capacity was unchanged. The thermodynamic modelling method to predict the behavior of the Mn-Fe-O and Co-Fe-O systems was validated, and the possibility to identify other mixed oxides becomes conceivable, by enabling the selection of transition metals additives for metal oxides destined for thermochemical energy storage applications.

Anchoring the Gas-Phase Acidity Scale from Hydrogen Sulfide to Pyrrole. Experimental Bond Dissociation Energies of Nitromethane, Ethanethiol, and Cyclopentadiene.

PubMed

Ervin, Kent M; Nickel, Alex A; Lanorio, Jerry G; Ghale, Surja B

2015-07-16

A meta-analysis of experimental information from a variety of sources is combined with statistical thermodynamics calculations to refine the gas-phase acidity scale from hydrogen sulfide to pyrrole. The absolute acidities of hydrogen sulfide, methanethiol, and pyrrole are evaluated from literature R-H bond energies and radical electron affinities to anchor the scale. Relative acidities from proton-transfer equilibrium experiments are used in a local thermochemical network optimized by least-squares analysis to obtain absolute acidities of 14 additional acids in the region. Thermal enthalpy and entropy corrections are applied using molecular parameters from density functional theory, with explicit calculation of hindered rotor energy levels for torsional modes. The analysis reduces the uncertainties of the absolute acidities of the 14 acids to within ±1.2 to ±3.3 kJ/mol, expressed as estimates of the 95% confidence level. The experimental gas-phase acidities are compared with calculations, with generally good agreement. For nitromethane, ethanethiol, and cyclopentadiene, the refined acidities can be combined with electron affinities of the corresponding radicals from photoelectron spectroscopy to obtain improved values of the C-H or S-H bond dissociation energies, yielding D298(H-CH2NO2) = 423.5 ± 2.2 kJ mol(-1), D298(C2H5S-H) = 364.7 ± 2.2 kJ mol(-1), and D298(C5H5-H) = 347.4 ± 2.2 kJ mol(-1). These values represent the best-available experimental bond dissociation energies for these species.

Experimental results on Zc(3900)

NASA Astrophysics Data System (ADS)

Shen, C. P.

2015-10-01

This report reviewed the recently discovered Zc(3900) at around 3.9 GeV/c2 in the π±J/ψ mass spectrum by the Belle and BESIII collaborations simultaneously. Belle collaboration observed it in the process e+e- → π+π- J/ψ within the Y (4260) signal region with a 967 fb-1 data sample using initial-stateradiation technology. BESIII collaboration discovered it in the same process at a fixed center-of-mass energy of 4.260 GeV using a 525 pb-1 data sample. The measured resonance masses and widths from Belle and BESIII measurements are consistent with each other within the errors. The Zc(3900) can be interpreted as a new charged charmonium-like state.

Myocardial Scar Imaging by Standard Single-Energy and Dual-Energy Late Enhancement Computed Tomography: Comparison to Pathology and Electroanatomical Map in an Experimental Chronic Infarct Porcine Model

PubMed Central

Truong, Quynh A.; Thai, Wai-ee; Wai, Bryan; Cordaro, Kevin; Cheng, Teresa; Beaudoin, Jonathan; Xiong, Guanglei; Cheung, Jim W.; Altman, Robert; Min, James K.; Singh, Jagmeet P.; Barrett, Conor D.; Danik, Stephan

2015-01-01

Background Myocardial scar is a substrate for ventricular tachycardia and sudden cardiac death. Late enhancement computed tomography (CT) imaging can detect scar, but it remains unclear whether newer late enhancement dual-energy (LE-DECT) acquisition has benefit over standard single-energy late enhancement (LE-CT). Objective We aim to compare late enhancement CT using newer LE-DECT acquisition and single-energy LE-CT acquisitions to pathology and electroanatomical map (EAM) in an experimental chronic myocardial infarction (MI) porcine study. Methods In 8 chronic MI pigs (59±5 kg), we performed dual-source CT, EAM, and pathology. For CT imaging, we performed 3 acquisitions at 10 minutes post-contrast: LE-CT 80 kV, LE-CT 100 kV, and LE-DECT with two post-processing software settings. Results Of the sequences, LE-CT 100 kV provided the best contrast-to-noise ratio (all p≤0.03) and correlation to pathology for scar (ρ=0.88). While LE-DECT overestimated scar (both p=0.02), LE-CT images did not (both p=0.08). On a segment basis (n=136), all CT sequences had high specificity (87–93%) and modest sensitivity (50–67%), with LE-CT 100 kV having the highest specificity of 93% for scar detection compared to pathology and agreement with EAM (κ 0.69). Conclusions Standard single-energy LE-CT, particularly 100kV, matched better to pathology and EAM than dual-energy LE-DECT for scar detection. Larger human trials as well as more technical-based studies that optimize varying different energies with newer hardware and software are warranted. PMID:25977115

Experimental determination of the effective point of measurement of cylindrical ionization chambers for high-energy photon and electron beams.

PubMed

Huang, Yanxiao; Willomitzer, Christian; Zakaria, Golam Abu; Hartmann, Guenther H

2010-01-01

Measurements of depth-dose curves in water phantom using a cylindrical ionization chamber require that its effective point of measurement is located at the measuring depth. Recommendations for the position of the effective point of measurement with respect to the central axis valid for high-energy electron and photon beams are given in dosimetry protocols. According to these protocols, the use of a constant shift P(eff) is currently recommended. However, this is still based on a very limited set of experimental results. It is therefore expected that an improved knowledge of the exact position of the effective point of measurement will further improve the accuracy of dosimetry. Recent publications have revealed that the position of the effective point of measurement is indeed varying with beam energy, field size and also with chamber geometry. The aim of this study is to investigate whether the shift of P(eff) can be taken to be constant and independent from the beam energy. An experimental determination of the effective point of measurement is presented based on a comparison between cylindrical chambers and a plane-parallel chamber using conventional dosimetry equipment. For electron beams, the determination is based on the comparison of halfvalue depth R(50) between the cylindrical chamber of interest and a well guarded plane-parallel Roos chamber. For photon beams, the depth of dose maximum, d(max), the depth of 80% dose, d(80), and the dose parameter PDD(10) were used. It was again found that the effective point of measurement for both, electron and photon beams Dosimetry, depends on the beam energy. The deviation from a constant value remains very small for photons, whereas significant deviations were found for electrons. It is therefore concluded that use of a single upstream shift value from the centre of the cylindrical chamber as recommended in current dosimetry protocols is adequate for photons, however inadequate for accurate electron beam dosimetry.

Experimental Investigation of Latent Heat Thermal Energy Storage for Bi-Modal Solar Thermal Propulsion (Briefing Charts)

DTIC Science & Technology

2014-07-01

applications • Mentioned as a potential buffer / storage material for TPVs • Brief mentions in the solar thermal literature...Charts 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Experimental Investigation of Latent Heat Thermal Energy Storage for 5a. CONTRACT...NUMBER In-House Bi-Modal Solar Thermal Propulsion 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Matthew R. Gilpin, David B. Scharfe

Application of an Unstructured Grid Navier-Stokes Solver to a Generic Helicopter Boby: Comparison of Unstructured Grid Results with Structured Grid Results and Experimental Results

NASA Technical Reports Server (NTRS)

Mineck, Raymond E.

1999-01-01

An unstructured-grid Navier-Stokes solver was used to predict the surface pressure distribution, the off-body flow field, the surface flow pattern, and integrated lift and drag coefficients on the ROBIN configuration (a generic helicopter) without a rotor at four angles of attack. The results are compared to those predicted by two structured- grid Navier-Stokes solvers and to experimental surface pressure distributions. The surface pressure distributions from the unstructured-grid Navier-Stokes solver are in good agreement with the results from the structured-grid Navier-Stokes solvers. Agreement with the experimental pressure coefficients is good over the forward portion of the body. However, agreement is poor on the lower portion of the mid-section of the body. Comparison of the predicted surface flow patterns showed similar regions of separated flow. Predicted lift and drag coefficients were in fair agreement with each other.

Robotic follower experimentation results: ready for FCS increment I

NASA Astrophysics Data System (ADS)

Jaczkowski, Jeffrey J.

2003-09-01

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.

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

NASA Astrophysics Data System (ADS)

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

2014-06-01

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.

Tilted wheel satellite attitude control with air-bearing table experimental results

NASA Astrophysics Data System (ADS)

Inumoh, Lawrence O.; Forshaw, Jason L.; Horri, Nadjim M.

2015-12-01

Gyroscopic actuators for satellite control have attracted significant research interest over the years, but their viability for the control of small satellites has only recently started to become clear. Research on variable speed gyroscopic actuators has long been focused on single gimbal actuators; double gimbal actuators typically operate at constant wheel spin rate and allow tilt angle ranges far larger than the ranges needed to operate most satellite missions. This research examines a tilted wheel, a newly proposed type of inertial actuator that can generate torques in all three principal axes of a rigid satellite using a spinning wheel and a double tilt mechanism. The tilt mechanism tilts the angular momentum vector about two axes providing two degree of freedom control, while variation of the wheel speed provides the third. The equations of motion of the system lead to a singularity-free system during nominal operation avoiding the need for complex steering logic. This paper describes the hardware design of the tilted wheel and the experimental setup behind both standalone and spherical air-bearing tables used to test it. Experimental results from the air bearing table are provided with the results depicting the high performance capabilities of the proposed actuator in torque generation.

Low-cost phase change material as an energy storage medium in building envelopes: Experimental and numerical analyses

DOE PAGES

Biswas, Kaushik; Abhari, Ramin

2014-10-03

A promising approach to increasing the energy efficiency of buildings is the implementation of a phase change material (PCM) in the building envelope. Numerous studies over the last two decades have reported the energy saving potential of PCMs in building envelopes, but their wide application has been inhibited, in part, by their high cost. This article describes a novel PCM made of naturally occurring fatty acids/glycerides trapped into high density polyethylene (HDPE) pellets and its performance in a building envelope application. The PCM-HDPE pellets were mixed with cellulose insulation and then added to an exterior wall of a test buildingmore » in a hot and humid climate, and tested over a period of several months, To demonstrate the efficacy of the PCM-enhanced cellulose insulation in reducing the building envelope heat gains and losses, side-by-side comparison was performed with another wall section filled with cellulose-only insulation. Further, numerical modeling of the test wall was performed to determine the actual impact of the PCM-HDPE pellets on wall-generated heating and cooling loads and the associated electricity consumption. The model was first validated using experimental data and then used for annual simulations using typical meteorological year (TMY3) weather data. Furthermore, this article presents the experimental data and numerical analyses showing the energy-saving potential of the new PCM.« less

Circular Samples as Objects for Magnetic Resonance Imaging - Mathematical Simulation, Experimental Results

NASA Astrophysics Data System (ADS)

Frollo, Ivan; Krafčík, Andrej; Andris, Peter; Přibil, Jiří; Dermek, Tomáš

2015-12-01

Circular samples are the frequent objects of "in-vitro" investigation using imaging method based on magnetic resonance principles. The goal of our investigation is imaging of thin planar layers without using the slide selection procedure, thus only 2D imaging or imaging of selected layers of samples in circular vessels, eppendorf tubes,.. compulsorily using procedure "slide selection". In spite of that the standard imaging methods was used, some specificity arise when mathematical modeling of these procedure is introduced. In the paper several mathematical models were presented that were compared with real experimental results. Circular magnetic samples were placed into the homogenous magnetic field of a low field imager based on nuclear magnetic resonance. For experimental verification an MRI 0.178 Tesla ESAOTE Opera imager was used.

Experimental evaluation of exhaust mixers for an Energy Efficient Engine

NASA Technical Reports Server (NTRS)

Kozlowski, H.; Kraft, G.

1980-01-01

Static scale model tests were conducted to evaluate exhaust system mixers for a high bypass ratio engine as part of the NASA sponsored Energy Efficient program. Gross thrust coefficients were measured for a series of mixer configurations which included variations in the number of mixer lobes, tailpipe length, mixer penetration, and length. All of these parameters have a significant impact on exhaust system performance. In addition, flow visualization pictures and pressure/temperature traverses were obtained for selected configurations. Parametric performance trends are discussed and the results considered relative to the Energy Efficient Engine program goals.

Summary of experimental heat-transfer results from the turbine hot section facility

NASA Technical Reports Server (NTRS)

Gladden, Herbert J.; Yeh, Fredrick C.

1993-01-01

Experimental data from the turbine Hot Section Facility are presented and discussed. These data include full-coverage film-cooled airfoil results as well as special instrumentation results obtained at simulated real engine conditions. Local measurements of airfoil wall temperature, airfoil gas-path static-pressure distribution, and local heat-transfer coefficient distributions are presented and discussed. In addition, measured gas and coolant temperatures and pressures are presented. These data are also compared with analyses from Euler and boundary-layer codes.

Stimulating Contributions to Public Goods through Information Feedback: Some Experimental Results

PubMed Central

Janssen, Marco A.; Lee, Allen; Sundaram, Hari

2016-01-01

In traditional public good experiments participants receive an endowment from the experimenter that can be invested in a public good or kept in a private account. In this paper we present an experimental environment where participants can invest time during five days to contribute to a public good. Participants can make contributions to a linear public good by logging into a web application and performing virtual actions. We compared four treatments, with different group sizes and information of (relative) performance of other groups. We find that information feedback about performance of other groups has a small positive effect if we control for various attributes of the groups. Moreover, we find a significant effect of the contributions of others in the group in the previous day on the number of points earned in the current day. Our results confirm that people participate more when participants in their group participate more, and are influenced by information about the relative performance of other groups. PMID:27459070

Experimental Study of Thermal Energy Storage Characteristics using Heat Pipe with Nano-Enhanced Phase Change Materials

NASA Astrophysics Data System (ADS)

Krishna, Jogi; Kishore, P. S.; Brusly Solomon, A.

2017-08-01

The paper presents experimental investigations to evaluate thermal performance of heat pipe using Nano Enhanced Phase Change Material (NEPCM) as an energy storage material (ESM) for electronic cooling applications. Water, Tricosane and nano enhanced Tricosane are used as energy storage materials, operating at different heating powers (13W, 18W and 23W) and fan speeds (3.4V and 5V) in the PCM cooling module. Three different volume percentages (0.5%, 1% and 2%) of Nano particles (Al2O3) are mixed with Tricosane which is the primary PCM. This experiment is conducted to study the temperature distributions of evaporator, condenser and PCM during the heating as well as cooling. The cooling module with heat pipe and nano enhanced Tricosane as energy storage material found to save higher fan power consumption compared to the cooling module that utilities only a heat pipe.

Experimental optimization of directed field ionization

NASA Astrophysics Data System (ADS)

Liu, Zhimin Cheryl; Gregoric, Vincent C.; Carroll, Thomas J.; Noel, Michael W.

2017-04-01

The state distribution of an ensemble of Rydberg atoms is commonly measured using selective field ionization. The resulting time resolved ionization signal from a single energy eigenstate tends to spread out due to the multiple avoided Stark level crossings atoms must traverse on the way to ionization. The shape of the ionization signal can be modified by adding a perturbation field to the main field ramp. Here, we present experimental results of the manipulation of the ionization signal using a genetic algorithm. We address how both the genetic algorithm and the experimental parameters were adjusted to achieve an optimized result. This work was supported by the National Science Foundation under Grants No. 1607335 and No. 1607377.

Design and Experimental Results for the S406 Airfoil

DTIC Science & Technology

2010-08-01

Concluded.45 46 (a) R = 0.50 × 106. Figure 14.- Comparison of theoretical and experimental section ch with transition free.aracteristics 47 (b) R...106. Figure 15.- Comparison of theoretical and experimental section ch with transition fixed.aracteristics 51 (b) R = 0.70 × 106. Figure 15...04986 4.088 .7022 .013251 −.04644 5.104 . 7845 .014147 −.04381 6.119 .8571 .015149 −.04019 7.135 .9294 .016691 −.03508 8.149 .9947 .017447 −.03106 9.162

Experimental and numerical study of the failure process and energy mechanisms of rock-like materials containing cross un-persistent joints under uniaxial compression.

PubMed

Cao, Rihong; Cao, Ping; Lin, Hang; Fan, Xiang

2017-01-01

Joints and fissures in natural rocks have a significant influence on the stability of the rock mass, and it is often necessary to evaluate strength failure and crack evolution behavior. In this paper, based on experimental tests and numerical simulation (PFC2D), the macro-mechanical behavior and energy mechanism of jointed rock-like specimens with cross non-persistent joints under uniaxial loading were investigated. The focus was to study the effect of joint dip angle α and intersection angle γ on the characteristic stress, the coalescence modes and the energy release of jointed rock-like specimens. For specimens with γ = 30° and 45°, the UCS (uniaxial compression strength), CIS (crack initiation stress) and CDiS (critical dilatancy stress) increase as α increases from 0° to 75°. When γ = 60° and 75°, the UCS, CIS and CDiS increase as α increases from 0° to 60° and decrease when α is over 60°. Both the inclination angle α and intersection angle γ have great influence on the failure pattern of pre-cracked specimens. With different α and γ, specimens exhibit 4 kinds of failure patterns. Both the experimental and numerical results show that the energy of a specimen has similar trends with characteristic stress as α increases.

Experimental determination of in situ utilization of lunar regolith for thermal energy storage

NASA Technical Reports Server (NTRS)

Richter, Scott W.

1992-01-01

A Lunar Thermal Energy from Regolith (LUTHER) experiment has been designed and fabricated at the NASA Lewis Research Center to determine the feasibility of using lunar soil as thermal energy storage media. The experimental apparatus includes an alumina ceramic canister which contains simulated lunar regolith, a heater, nine heat shields, a heat transfer cold jacket, and 19 type-B platinum rhodium thermocouples. The simulated lunar regolith is a basalt that closely resembles the lunar basalt returned to earth by the Apollo missions. The experiment will test the effects of vacuum, particle size, and density on the thermophysical properties of the regolith, which include melt temperature, specific heat thermal conductivity, and latent heat of storage. Two separate tests, using two different heaters, will be performed to study the effect of heating the system using radiative and conductive heat transfer. A finite differencing SINDA model was developed at NASA Lewis Research Center to predict the performance of the LUTHER experiment. The code will predict the effects of vacuum, particle size, and density has on the heat transfer to the simulated regolith.

Experimental demonstration of plasmon enhanced energy transfer rate in NaYF4:Yb3+,Er3+ upconversion nanoparticles

PubMed Central

Lu, Dawei; Mao, Chenchen; Cho, Suehyun K.; Ahn, Sungmo; Park, Wounjhang

2016-01-01

Energy transfer upconversion (ETU) is known to be the most efficient frequency upconversion mechanism. Surface plasmon can further enhance the upconversion process, opening doors to many applications. However, ETU is a complex process involving competing transitions between multiple energy levels and it has been difficult to precisely determine the enhancement mechanisms. In this paper, we report a systematic study on the dynamics of the ETU process in NaYF4:Yb3+,Er3+ nanoparticles deposited on plasmonic nanograting structure. From the transient near-infrared photoluminescence under various excitation power densities, we observed faster energy transfer rates under stronger excitation conditions until it reached saturation where the highest internal upconversion efficiency was achieved. The experimental data were analyzed using the complete set of rate equations. The internal upconversion efficiency was found to be 56% and 36%, respectively, with and without the plasmonic nanograting. We also analyzed the transient green emission and found that it is determined by the infrared transition rate. To our knowledge, this is the first report of experimentally measured internal upconversion efficiency in plasmon enhanced upconversion material. Our work decouples the internal upconversion efficiency from the overall upconverted luminescence efficiency, allowing more targeted engineering for efficiency improvement. PMID:26739230

Numerical and experimental results on the spectral wave transfer in finite depth

NASA Astrophysics Data System (ADS)

Benassai, Guido

2016-04-01

Determination of the form of the one-dimensional surface gravity wave spectrum in water of finite depth is important for many scientific and engineering applications. Spectral parameters of deep water and intermediate depth waves serve as input data for the design of all coastal structures and for the description of many coastal processes. Moreover, the wave spectra are given as an input for the response and seakeeping calculations of high speed vessels in extreme sea conditions and for reliable calculations of the amount of energy to be extracted by wave energy converters (WEC). Available data on finite depth spectral form is generally extrapolated from parametric forms applicable in deep water (e.g., JONSWAP) [Hasselmann et al., 1973; Mitsuyasu et al., 1980; Kahma, 1981; Donelan et al., 1992; Zakharov, 2005). The present paper gives a contribution in this field through the validation of the offshore energy spectra transfer from given spectral forms through the measurement of inshore wave heights and spectra. The wave spectra on deep water were recorded offshore Ponza by the Wave Measurement Network (Piscopia et al.,2002). The field regressions between the spectral parameters, fp and the nondimensional energy with the fetch length were evaluated for fetch-limited sea conditions. These regressions gave the values of the spectral parameters for the site of interest. The offshore wave spectra were transfered from the measurement station offshore Ponza to a site located offshore the Gulf of Salerno. The offshore local wave spectra so obtained were transfered on the coastline with the TMA model (Bouws et al., 1985). Finally the numerical results, in terms of significant wave heights, were compared with the wave data recorded by a meteo-oceanographic station owned by Naples Hydrographic Office on the coastline of Salerno in 9m depth. Some considerations about the wave energy to be potentially extracted by Wave Energy Converters were done and the results were discussed.

Supersonic Retropropulsion Experimental Results from the NASA Langley Unitary Plan Wind Tunnel

NASA Technical Reports Server (NTRS)

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

2011-01-01

A new supersonic retropropulsion experimental effort, intended to provide code validation data, was recently completed in the Langley Research Center Unitary Plan Wind Tunnel Test Section 2 over the Mach number range from 2.4 to 4.6. The experimental model was designed using insights gained from pre-test computations, which were instrumental for sizing and refining the model to minimize tunnel wall interference and internal flow separation concerns. A 5-in diameter 70-deg sphere-cone forebody with a roughly 10-in long cylindrical aftbody was the baseline configuration selected for this study. The forebody was designed to accommodate up to four 4:1 area ratio supersonic nozzles. Primary measurements for this model were a large number of surface pressures on the forebody and aftbody. Supplemental data included high-speed Schlieren video and internal pressures and temperatures. The run matrix was developed to allow for the quantification of various sources of experimental uncertainty, such as random errors due to run-to-run variations and bias errors due to flow field or model misalignments. Preliminary results and observations from the test are presented, while detailed data and uncertainty analyses are ongoing.

Sharing success: State energy program special projects results

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

NONE

2000-03-15

The State Energy Program was created in 1996 by an act of Congress through the consolidation of the State Energy Conservation Program (SECP) and the Institutional Conservation Program (ICP). Formerly, SECP provided funding for a variety of energy efficiency and renewable energy projects, and ICP assisted schools and hospitals with technical analysis and installation of energy conservation measures. Through these programs, more than 8,000 specific State conservation projects have been implemented since 1983 and more than 69,000 buildings have been made more energy efficient since 1979. The Department of Energy's Office of Energy Efficiency and Renewable Energy recognized the valuemore » of delivering programs through the States and created Special Projects in 1996. This report is an overview of State Energy Program operations, strategic focus, activities and accomplishments.« less

Experimental study of the energy dependence of the total cross section for the 6He + natSi and 9Li + natSi reactions

NASA Astrophysics Data System (ADS)

Sobolev, Yu. G.; Penionzhkevich, Yu. E.; Aznabaev, D.; Zemlyanaya, E. V.; Ivanov, M. P.; Kabdrakhimova, G. D.; Kabyshev, A. M.; Knyazev, A. G.; Kugler, A.; Lashmanov, N. A.; Lukyanov, K. V.; Maj, A.; Maslov, V. A.; Mendibayev, K.; Skobelev, N. K.; Slepnev, R. S.; Smirnov, V. V.; Testov, D.

2017-11-01

New experimental measurements of the total reaction cross sections for the 6He + natSi and 9Li + natSi processes in the energy range of 5 to 40 A MeV are presented. A modified transmission method based on high-efficiency detection of prompt n-γ radiation has been used in the experiment. A bump is observed for the first time in the energy dependence σR( E) at E ˜ 10-30 A MeV for the 9Li + natSi reaction, and existence of the bump in σR( E) at E ˜ 10-20 A MeV first observed in the standard transmission experiments is experimentally confirmed for the 6He + natSi reaction. Theoretical analysis of the measured 6He + natSi and 9Li + natSi reaction cross sections is performed within the microscopic double folding model. Disagreement is observed between the experimental and theoretical cross sections in the region of the bump at the energies of 10 to 20 A MeV, which requires further study.

Experimental and analytical study of high velocity impact on Kevlar/Epoxy composite plates

NASA Astrophysics Data System (ADS)

Sikarwar, Rahul S.; Velmurugan, Raman; Madhu, Velmuri

2012-12-01

In the present study, impact behavior of Kevlar/Epoxy composite plates has been carried out experimentally by considering different thicknesses and lay-up sequences and compared with analytical results. The effect of thickness, lay-up sequence on energy absorbing capacity has been studied for high velocity impact. Four lay-up sequences and four thickness values have been considered. Initial velocities and residual velocities are measured experimentally to calculate the energy absorbing capacity of laminates. Residual velocity of projectile and energy absorbed by laminates are calculated analytically. The results obtained from analytical study are found to be in good agreement with experimental results. It is observed from the study that 0/90 lay-up sequence is most effective for impact resistance. Delamination area is maximum on the back side of the plate for all thickness values and lay-up sequences. The delamination area on the back is maximum for 0/90/45/-45 laminates compared to other lay-up sequences.

Energy spectrum and transport in narrow HgTe quantum wells

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

Germanenko, A. V., E-mail: Alexander.Germanenko@urfu.ru; Minkov, G. M.; Rut, O. E.

The results of an experimental study of the transport phenomena and the hole energy spectrum of two-dimensional systems in the quantum well of HgTe zero-gap semiconductor with normal arrangement of quantum-confinement subbands are presented. An analysis of the experimental data allows us to reconstruct the carrier energy spectrum near the hole subband extrema. The results are interpreted using the standard kP model.

Results of a higgs boson searches in the ATLAS and CMS experiments at the large hadron collider at energies 7 and 8 TeV

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

Artamonov, A. A.; Epshteyn, V. S.; Gavrilov, V. B.

2016-05-15

Recent achievements of the ATLAS and CMS experiments at the Large Hadron Collider searching for a Higgs boson are summarized. A new particle with the mass of 125 GeV and properties expected for the Standard Model Higgs boson was discovered three years ago in these experiments in proton-proton collisions when analyzing part of the data taken at the centre-of-mass energies 7 TeV and 8 TeV in 2011 and 2012 year exposures. Today all the data are processed and fully analyzed. Experimental results of studies of individual Higgs boson decay channels as well as their combination to extract such properties asmore » mass, signal strength, coupling constants, spin and parity are reviewed. All experimental results are found to be compatible with the Standard Model predictions.« less

Band structure effects in the energy loss of low-energy protons and deuterons in thin films of Pt

NASA Astrophysics Data System (ADS)

Celedón, C. E.; Sánchez, E. A.; Salazar Alarcón, L.; Guimpel, J.; Cortés, A.; Vargas, P.; Arista, N. R.

2015-10-01

We have investigated experimentally and by computer simulations the energy-loss and angular distribution of low energy (E < 10 keV) protons and deuterons transmitted through thin polycrystalline platinum films. The experimental results show significant deviations from the expected velocity dependence of the stopping power in the range of very low energies with respect to the predictions of the Density Functional Theory for a jellium model. This behavior is similar to those observed in other transition metals such as Cu, Ag and Au, but different from the linear dependence recently observed in another transition metal, Pd, which belongs to the same Group of Pt in the Periodic Table. These differences are analyzed in term of the properties of the electronic bands corresponding to Pt and Pd, represented in terms of the corresponding density of states. The present experiments include also a detailed study of the angular dependence of the energy loss and the angular distributions of transmitted protons and deuterons. The results are compared with computer simulations based on the Monte Carlo method and with a theoretical model that evaluates the contributions of elastic collisions, path length effects in the inelastic energy losses, and the effects of the foil roughness. The results of the analysis obtained from these various approaches provide a consistent and comprehensive description of the experimental findings.

November 2013 Analysis of High Energy Electrons on the Japan Experimental Module (JEM: Kibo)

NASA Technical Reports Server (NTRS)

Badavi, Francis F.; Matsumoto, Haruhisa; Koga, Kiyokazu; Mertens, Christopher J.; Slaba, Tony C.; Norbury, John W.

2015-01-01

Albedo (precipitating/splash) electrons, created by galactic cosmic rays (GCR) interaction with the upper atmosphere move upwards away from the surface of the earth. In the past validation work these particles were often considered to have negligible contribution to astronaut radiation exposure on the International Space Station (ISS). Estimates of astronaut exposure based on the available Computer Aided Design (CAD) models of ISS consistently underestimated measurements onboard ISS when the contribution of albedo particles to exposure were neglected. Recent measurements of high energy electrons outside ISS Japan Experimental Module (JEM) using Exposed Facility (EF), Space Environment Data Acquisition Equipment - Attached Payload (SEDA-AP) and Standard DOse Monitor (SDOM), indicates the presence of high energy electrons at ISS altitude. In this presentation the status of these energetic electrons is reviewed and mechanism for the creation of these particles inside/outside South Atlantic Anomaly (SAA) region explained. In addition, limited dosimetric evaluation of these electrons at 600 MeV and 10 GeV is presented.

Estimation of Supercapacitor Energy Storage Based on Fractional Differential Equations.

PubMed

Kopka, Ryszard

2017-12-22

In this paper, new results on using only voltage measurements on supercapacitor terminals for estimation of accumulated energy are presented. For this purpose, a study based on application of fractional-order models of supercapacitor charging/discharging circuits is undertaken. Parameter estimates of the models are then used to assess the amount of the energy accumulated in supercapacitor. The obtained results are compared with energy determined experimentally by measuring voltage and current on supercapacitor terminals. All the tests are repeated for various input signal shapes and parameters. Very high consistency between estimated and experimental results fully confirm suitability of the proposed approach and thus applicability of the fractional calculus to modelling of supercapacitor energy storage.

Energy characteristics of Darrieus rotor ( review)

NASA Astrophysics Data System (ADS)

Gorelov, D. N.

2010-09-01

Presented below is the review of the results of experimental studies of energy characteristics of Darrieus rotor with vertical rotation axis. Influence of main geometry parameters of the rotor on its energy characteristics has been analyzed. It is shown that Darrieus rotor may have the higher level of energy characteristics than the best propeller wind turbines.

Roles for gut vagal sensory signals in determining energy availability and energy expenditure.

PubMed

Schwartz, Gary J

2018-08-15

The gut sensory vagus transmits a wide range of meal-related mechanical, chemical and gut peptide signals from gastrointestinal and hepatic tissues to the central nervous system at the level of the caudal brainstem. Results from studies using neurophysiological, behavioral physiological and metabolic approaches that challenge the integrity of this gut-brain axis support an important role for these gut signals in the negative feedback control of energy availability by limiting food intake during a meal. These experimental approaches have now been applied to identify important and unanticipated contributions of the vagal sensory gut-brain axis to the control of two additional effectors of overall energy balance: the feedback control of endogenous energy availability through hepatic glucose production and metabolism, and the control of energy expenditure through brown adipose tissue thermogenesis. Taken together, these studies reveal the pleiotropic influences of gut vagal meal-related signals on energy balance, and encourage experimental efforts aimed at understanding how the brainstem represents, organizes and coordinates gut vagal sensory signals with these three determinants of energy homeostasis. Copyright © 2018 Elsevier B.V. All rights reserved.

Experimental and Theoretical Results in Output Trajectory Redesign for Flexible Structures

NASA Technical Reports Server (NTRS)

Dewey, J. S.; Leang, K.; Devasia, S.

1998-01-01

In this paper we study the optimal redesign of output trajectories for linear invertible systems. This is particularly important for tracking control of flexible structures because the input-state trajectores, that achieve tracking of the required output may cause excessive vibrations in the structure. We pose and solve this problem, in the context of linear systems, 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.

Vibration Based Crack Detection in a Rotating Disk. Part 2; Experimental Results

NASA Technical Reports Server (NTRS)

Gyekenyesi, Andrew L.; Sawicki, Jerzy T.; Martin, Richard E.; Haase, Wayne C.; Baaklini, George

2005-01-01

This paper describes the experimental results concerning the detection of a crack in a rotating disk. The goal was to utilize blade tip clearance and shaft vibration measurements to monitor changes in the system's center of mass and/or blade deformation behaviors. The concept of the approach is based on the fact that the development of a disk crack results in a distorted strain field within the component. As a result, a minute deformation in the disk's geometry as well as a change in the system's center of mass occurs. Here, a notch was used to simulate an actual crack. The vibration based experimental results failed to identify the existence of a notch when utilizing the approach described above, even with a rather large, circumferential notch (l.2 in.) located approximately mid-span on the disk (disk radius = 4.63 in. with notch at r = 2.12 in.). This was somewhat expected, since the finite element based results in Part 1 of this study predicted changes in blade tip clearance as well as center of mass shifts due to a notch to be less than 0.001 in. Therefore, the small changes incurred by the notch could not be differentiated from the mechanical and electrical noise of the rotor system. Although the crack detection technique of interest failed to identify the existence ofthe notch, the vibration data produced and captured here will be utilized in upcoming studies that will focus on different data mining techniques concerning damage detection in a disk.

Self-replenishing ability of cross-linked low surface energy polymer films investigated by a complementary experimental-simulation approach

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

Esteves, A. C. C., E-mail: a.c.c.esteves@tue.nl, E-mail: g.dewith@tue.nl; Lyakhova, K.; Riel, J. M. van

2014-03-28

Nowadays, many self-healing strategies are available for recovering mechanical damage of bulk polymeric materials. The recovery of surface-dependent functionalities on polymer films is, however, equally important and has been less investigated. In this work we study the ability of low surface energy cross-linked poly(ester urethane) networks containing perfluorinated dangling chains to self-replenish their surface, after being submitted to repeated surface damage. For this purpose we used a combined experimental-simulation approach. Experimentally, the cross-linked films were intentionally damaged by cryo-microtoming to remove top layers and create new surfaces which were characterized by water Contact Angle measurements and X-Ray Photoelectron Spectroscopy. Themore » same systems were simultaneously represented by a Dissipative Particles Dynamics simulation method, where the damage was modeled by removing the top film layers in the simulation box and replacing it by new “air” beads. The influence of different experimental parameters, such as the concentration of the low surface energy component and the molecular mobility span of the dangling chains, on the surface recovery is discussed. The combined approach reveals important details of the self-replenishing ability of damaged polymer films such as the occurrence of multiple-healing events, the self-replenishing efficiency, and the minimum “healing agent” concentration for a maximum recovery.« less

A far-field radio-frequency experimental exposure system with unrestrained mice.

PubMed

Hansen, Jared W; Asif, Sajid; Singelmann, Lauren; Khan, Muhammad Saeed; Ghosh, Sumit; Gustad, Tom; Doetkott, Curt; Braaten, Benjamin D; Ewert, Daniel L

2015-01-01

Many studies have been performed on exploring the effects of radio-frequency (RF) energy on biological function in vivo. In particular, gene expression results have been inconclusive due, in part, to a lack of a standardized experimental procedure. This research describes a new far field RF exposure system for unrestrained murine models that reduces experimental error. The experimental procedure includes the materials used, the creation of a patch antenna, the uncertainty analysis of the equipment, characterization of the test room, experimental equipment used and setup, power density and specific absorption rate experiment, and discussion. The result of this research is an experimental exposure system to be applied to future biological studies.

State Energy Program Results: More Projects That Work

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

Not Available

1998-12-01

A Summary of Success stories of the State Energy Programs. The goal of the State Energy Program is to strengthen the capabilities of States to promote energy efficiency and to adopt renewable energy technologies, thereby helping the nation save energy and realize a stronger economy, cleaner environment, and a more secure future.

Free energy of solvated salt bridges: a simulation and experimental study.

PubMed

White, Andrew D; Keefe, Andrew J; Ella-Menye, Jean-Rene; Nowinski, Ann K; Shao, Qing; Pfaendtner, Jim; Jiang, Shaoyi

2013-06-20

Charged amino acids are the most common on surfaces of proteins and understanding the interactions between these charged amino acids, salt bridging, is crucial for understanding protein-protein interactions. Previous simulations have been limited to implicit solvent or fixed binding geometry due to the sampling required for converged free energies. Using well-tempered metadynamics, we have calculated salt bridge free energy surfaces in water and confirmed the results with NMR experiments. The simulations give binding free energies, quantitative ranking of salt bridging strength, and insights into the hydration of the salt bridges. The arginine-aspartate salt bridge was found to be the weakest and arginine-glutamate the strongest, showing that arginine can discriminate between aspartate and glutamate, whereas the salt bridges with lysine are indistinguishable in their free energy. The salt bridging hydration is found to be complementary to salt bridge orientation with arginine having specific orientations.

Experimental analysis of the dynamical response of energy harvesting devices based on bistable laminated plates.

PubMed

Syta, A; Bowen, C R; Kim, H A; Rysak, A; Litak, G

The use of bistable laminates is a potential approach to realize broadband piezoelectric based energy harvesting systems. In this paper the dynamic response of a piezoelectric material attached to a bistable laminate plate is examined based on the experimental generated voltage time series. The system was subjected to harmonic excitations and exhibited single-well and snap-through vibrations of both periodic and chaotic character. To identify the dynamics of the system response we examined the frequency spectrum, bifurcation diagrams, phase portraits, and the 0-1 test.

Low-energy neutrinos

NASA Astrophysics Data System (ADS)

Ludhova, Livia

2016-05-01

There exist several kinds of sources emitting neutrinos in the MeV energy range. These low-energy neutrinos from different sources can be often detected by the same multipurpose detectors. The status-of-art of the field of solar neutrinos, geoneutrinos, and the search for sterile neutrino with artificial neutrino sources is provided here; other neutrino sources, as for example reactor or high-energy neutrinos, are described elsewhere. For each of these three fields, the present-day motivation and open questions, as well as the latest experimental results and future perspectives are discussed.

Experimental and raytrace results for throat-to-throat compound parabolic concentrators

NASA Technical Reports Server (NTRS)

Leviton, D. B.; Leitch, J. W.

1986-01-01

Compound parabolic concentrators are nonimaging cone-shaped optics with useful angular transmission characteristics. Two cones used throat-to-throat accept radiant flux within one well-defined acceptance angle and redistribute it into another. If the entrance cone is fed with Lambertian flux, the exit cone produces a beam whose half-angle is the exit cone's acceptance angle and whose cross section shows uniform irradiance from near the exit mouth to infinity. (The pair is a beam angle transformer). The design of one pair of cones is discussed, also an experiment to map the irradiance of the emergent beam, and a raytracing program which models the cones fed by Lambertian flux. Experimental results compare favorably with raytrace results.

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

NASA Astrophysics Data System (ADS)

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

2008-06-01

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.

Drying in porous media with gravity-stabilized fronts: experimental results.

PubMed

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

2012-08-01

In a recent paper [Yiotis et al., Phys. Rev. E 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 Ca(f), Bond Bo, and Sherwood Sh numbers.

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)

Morgan, Harry L., Jr.

2002-01-01

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.

Experimental Research of a New Wave Energy Conversion Device

NASA Astrophysics Data System (ADS)

Lu, Zhongyue; Shang, Jianzhong; Luo, Zirong; Sun, Chongfei; Chen, Gewei

2018-01-01

With the increasing tension of contemporary social energy, the development and utilization of renewable energy has become an important development direction. As an important part of renewable energy, wave energy has the characteristics of green environmental protection and abundant reserves, attracting more investment and research. For small marine equipment energy supply problem, this paper puts forward a micro wave energy conversion device as the basic of heaving motion of waves in the ocean. This paper designed a new type of power output device can solve the micro wave energy conversion problem.

Surface energy of talc and chlorite: Comparison between electronegativity calculation and immersion results.

PubMed

Douillard, Jean-Marc; Salles, Fabrice; Henry, Marc; Malandrini, Harold; Clauss, Frédéric

2007-01-15

The surface energies of talc and chlorite is computed using a simple model, which uses the calculation of the electrostatic energy of the crystal. It is necessary to calculate the atomic charges. We have chosen to follow Henry's model of determination of partial charges using scales of electronegativity and hardness. The results are in correct agreement with a determination of the surface energy obtained from an analysis of the heat of immersion data. Both results indicate that the surface energy of talc is lower than the surface energy of chlorite, in agreement with observed behavior of wettability. The influence of Al and Fe on this phenomenon is discussed. Surface energy of this type of solids seems to depend more strongly on the geometry of the crystal than on the type of atoms pointing out of the surface; i.e., the surface energy depends more on the physics of the system than on its chemistry.

Experimental investigation of internal tides generated by finite-height topography

NASA Astrophysics Data System (ADS)

Wang, Shuya; Chen, Xu; Wang, Jinhu; Meng, Jing

2018-06-01

Internal tides generated by finite-height topography are investigated in the laboratory, and the particle image velocimetry (PIV) technique is applied to measure the velocity fields. The energy, energy flux, and vertical mode structure of the internal tides are calculated and analyzed. The experimental results indicate that the strength of the wave field is mainly affected by the normalized topography height. The rays radiated from the taller topography are wider than those radiated from the lower topography. Both the experimental and theoretical results indicate that the normalized energy and energy flux of the internal tides are mainly determined by the normalized topography height, and the increase of the two quantities follows a quadratic function, and they almost remain unchanged with different normalized frequencies except for higher frequency. The percentage of energy for mode-1 and mode-2 internal tides is determined not only by frequency but also by topography height. In addition, an "inherent normalized frequency" is observed in the experiment, at which the percentage of energy for mode 1 and mode 2 does not vary with topography height. The decay rate of internal tide energy in the near field and far field is also estimated, with average values of 36.5 and 7.5%, respectively.

High energy gamma ray results from the second small astronomy satellite

NASA Technical Reports Server (NTRS)

Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Thompson, D. J.; Bignami, G. F.; Oegelman, H.; Oezel, M. F.; Tuemer, T.

1974-01-01

A high energy (35 MeV) gamma ray telescope employing a thirty-two level magnetic core spark chamber system was flown on SAS 2. The high energy galactic gamma radiation is observed to dominate over the general diffuse radiation along the entire galactic plane, and when examined in detail, the longitudinal and latitudinal distribution seem generally correlated with galactic structural features, particularly with arm segments. The general high energy gamma radiation from the galactic plane, explained on the basis of its angular distribution and magnitude, probably results primarily from cosmic ray interactions with interstellar matter.

Out-of-plane buckling of pantographic fabrics in displacement-controlled shear tests: experimental results and model validation

NASA Astrophysics Data System (ADS)

Barchiesi, Emilio; Ganzosch, Gregor; Liebold, Christian; Placidi, Luca; Grygoruk, Roman; Müller, Wolfgang H.

2018-01-01

Due to the latest advancements in 3D printing technology and rapid prototyping techniques, the production of materials with complex geometries has become more affordable than ever. Pantographic structures, because of their attractive features, both in dynamics and statics and both in elastic and inelastic deformation regimes, deserve to be thoroughly investigated with experimental and theoretical tools. Herein, experimental results relative to displacement-controlled large deformation shear loading tests of pantographic structures are reported. In particular, five differently sized samples are analyzed up to first rupture. Results show that the deformation behavior is strongly nonlinear, and the structures are capable of undergoing large elastic deformations without reaching complete failure. Finally, a cutting edge model is validated by means of these experimental results.

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

NASA Technical Reports Server (NTRS)

Dewey, J. S.; Devasia, Santosh

1996-01-01

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.

Study on Properties of Energy Spectra of the Molecular Crystals

NASA Astrophysics Data System (ADS)

Pang, Xiao-Feng; Chen, Xiang-Rong

The energy-spectra of nonlinear vibration of molecular crystals such as acetanilide have been calculated by using discrete nonlinear Schrödinger equation appropriate to the systems, containing various interactions. The energy levels including higher excited states are basically consistent with experimental values obtained by infrared absorption and Raman scattering in acetanilide. We further give the features of distribution of the energy-spectra for the acetanilide. Using the energy spectra we also explained well experimental results obtained by Careri et al..

Supersonic flow with feeding of energy

NASA Technical Reports Server (NTRS)

Zaremba, W.

1985-01-01

The present work discusses the results of some experimental studies on the possibility of attenuating shock waves in a supersonic flow. The shock waves were formed by an external source of electrical energy. An electromechanical method is described that permits partial recovery of the expended energy.

Multiscale modeling and experimental interpretation of perovskite oxide materials in thermochemical energy storage and conversion for application in concentrating solar power

NASA Astrophysics Data System (ADS)

Albrecht, Kevin J.

storage in CSP plants are presented. Comparisons of sweep gas and vacuum pumping reduction as well as hot storage conditions indicate that solar-to-electric efficiencies are higher for sweep gas reduction system at equivalent values of energy storage if the energy parasitics of commercially available devices are considered. However, if vacuum pump efficiency between 15% and 30% can be achieved, the reduction methods will be approximately equal. Reducing condition oxygen partial pressures below 10-3 bar for sweep gas reduction and 10-2 bar for vacuum pumping reduction result in large electrical parasitics, which significantly reduce solar-to-electric efficiency. A model based interpretation of experimental measurements made for perovskite redox cycling using sweep gas in a packed bed is presented. The model indicates that long reduction times for equilibrating perovskites with low oxygen partial pressure sweep gas, compared to reoxidation, are primarily due to the oxygen carrying capacity of high purity sweep gas and not surface kinetic limitations. Therefore, achieving rapid reduction in the limited receiver residence time will be controlled by the quantity of sweep gas introduced. Effective kinetic parameters considering surface reaction and radial particle diffusion are fit to the experimental data. Variable order rate expressions without significant particle radial diffusion limitations are shown to be capable of representing the reduction and oxidation data. Modeling of a particle reduction receiver using continuous flow of perovskite solid and sweep gas in counter-flow configuration has identified issues with managing the oxygen evolved by the solid as well as sweep gas flow rates. Introducing sweep gas quantities necessary for equilibrating the solid with oxygen partial pressures below 10-2 are shown to result in gas phase velocities above the entrainment velocity of 500 um particles. Receiver designs with considerations for gas management are investigated and the

An energy-consistent fracture model for ferroelectrics

NASA Astrophysics Data System (ADS)

Miao, Hongchen; Li, Faxin

2017-02-01

The fracture behavior of ferroelectrics has been intensively studied in recent decades, though currently a widely accepted fracture mechanism is still lacking. In this work, enlightened by previous experimental observations that crack propagation in ferroelectrics is always accompanied by domain switching, we propose a micromechanical model in which both crack propagation and domain switching are controlled by energy-based criteria. Both electric energy and mechanical energy can induce domain switching, while only mechanical energy can drive crack propagation. Furthermore, constrained domain switching is considered in this model, leading to the gradient domain switching zone near the crack tip. Analysis results show that stress-induced ferroelastic switching always has a toughening effect as the mechanical energy release rate serves as the driving force for both fracture and domain switching. In comparison, the electric-field-induced switching may have either a toughening or detoughening effect. The proposed model can qualitatively agree with the existing experimental results.

Analytical and Experimental Investigations of Sodium Heat Pipes and Thermal Energy Storage Systems.

DTIC Science & Technology

1982-01-01

continued) Figure Page 5.1 Cylindrical container for eutectic salt (LiF-NgF -KF) . . . . . . 91 5.2 TESC sample . . . . . . ... . . 0...of fluorides of Mg, Li and K. Experimental results have been used to verify the melting point, and latent heat of fusion of the eutectic salt , in...a melting or solidification curve will provide experimental verification for the latent heat value and melting point of a given eutectic salt . In the

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

NASA Astrophysics Data System (ADS)

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

2010-06-01

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

Experimental study on secondary electron emission characteristics of Cu

NASA Astrophysics Data System (ADS)

Liu, Shenghua; Liu, Yudong; Wang, Pengcheng; Liu, Weibin; Pei, Guoxi; Zeng, Lei; Sun, Xiaoyang

2018-02-01

Secondary electron emission (SEE) of a surface is the origin of the multipacting effect which could seriously deteriorate beam quality and even perturb the normal operation of particle accelerators. Experimental measurements on secondary electron yield (SEY) for different materials and coatings have been developed in many accelerator laboratories. In fact, the SEY is just one parameter of secondary electron emission characteristics which include spatial and energy distribution of emitted electrons. A novel experimental apparatus was set up in China Spallation Neutron Source, and an innovative method was applied to obtain the whole characteristics of SEE. Taking Cu as the sample, secondary electron yield, its dependence on beam injection angle, and the spatial and energy distribution of secondary electrons were achieved with this measurement device. The method for spatial distribution measurement was first proposed and verified experimentally. This contribution also tries to give all the experimental results a reasonable theoretical analysis and explanation.

Experimental analysis of Hybridised Energy Storage Systems for automotive applications

NASA Astrophysics Data System (ADS)

Sarwar, Wasim; Engstrom, Timothy; Marinescu, Monica; Green, Nick; Taylor, Nigel; Offer, Gregory J.

2016-08-01

The requirements of the Energy Storage System (ESS) for an electrified vehicle portfolio consisting of a range of vehicles from micro Hybrid Electric Vehicle (mHEV) to a Battery Electric Vehicle (BEV) vary considerably. To reduce development cost of an electrified powertrain portfolio, a modular system would ideally be scaled across each vehicle; however, the conflicting requirements of a mHEV and BEV prevent this. This study investigates whether it is possible to combine supercapacitors suitable for an mHEV with high-energy batteries suitable for use in a BEV to create a Hybridised Energy Storage System (HESS) suitable for use in a HEV. A passive HESS is found to be capable of meeting the electrical demands of a HEV drive cycle; the operating principles of HESSs are discussed and factors limiting system performance are explored. The performance of the HESS is found to be significantly less temperature dependent than battery-only systems, however the heat generated suggests a requirement for thermal management. As the HESS degrades (at a similar rate to a specialised high-power-battery), battery resistance rises faster than supercapacitor resistance; as a result, the supercapacitor provides a greater current contribution, therefore the energy throughput, temperature rise and degradation of the batteries is reduced.

Laser-induced damage of fused silica optics at 355 nm due to backward stimulated Brillouin scattering: experimental and theoretical results.

PubMed

Lamaignère, Laurent; Gaudfrin, Kévin; Donval, Thierry; Natoli, Jeanyves; Sajer, Jean-Michel; Penninckx, Denis; Courchinoux, Roger; Diaz, Romain

2018-04-30

Forward pump pulses with nanosecond duration are able to generate an acoustic wave via electrostriction through a few centimeters of bulk silica. Part of the incident energy is then scattered back on this sound wave, creating a backward Stokes pulse. This phenomenon known as stimulated Brillouin scattering (SBS) might induce first energy-loss, variable change of the temporal waveform depending on the location in the spatial profile making accurate metrology impossible, and moreover it might also initiate front surface damage making the optics unusable. Experiments performed on thick fused silica optics at 355 nm with single longitudinal mode pulses allowed us to detect, observe and quantify these backward pulses. Experimental results are first compared to theoretical calculations in order to strengthen our confidence in metrology. On this basis a phase-modulator has been implemented on the continuous-wave seeders of the lasers leading to pulses with a wide spectrum that suppress SBS and do not exhibit temporal overshoots that also reduce Kerr effects. The developed set-ups are used to check the reduction of the backward stimulated Brillouin scattering and they allow measuring with accuracy the rear surface damage of thick fused silica optics.

Preliminary Test Results of Heshe Hydrogeological Experimental Well Station in Taiwan

NASA Astrophysics Data System (ADS)

Chuang, P.; Liu, C.; Lin, M.; Chan, W.; Lee, T.; Chia, Y.; Teng, M.; Liu, C.

2013-12-01

Safe disposal of radioactive waste is a critical issue for the development of nuclear energy. The design of final disposal system is based on the concept of multiple barriers which integrate the natural barriers and engineering barriers for long-term isolation of radioactive wastes. As groundwater is the major medium that can transport radionuclides to our living environment, it is essential to characterize groundwater flow at the disposal site. Taiwan is located at the boundary between the Eurasian plate and the Philippine Sea plate. Geologic formations are often fractured due to tectonic compression and extension. In this study, a well station for the research and development of hydrogeological techniques was established at the Experimental Forest of the National Taiwan University in central Taiwan. There are 10 testing wells, ranging in depth from 25 m to 100 m, at the station. The bedrock beneath the regolith is highly fractured mudstone. As fracture is the preferential pathway of the groundwater flow, the focus of in-situ tests is to investigate the location of permeable fractures and the connection of permeable fractures. Several field tests have been conducted, including geophysical logging, heat-pulse flowmeter, hydraulic test, tracer test and double packer test, for the development of advanced technologies to detect the preferential groundwater flow in fractured rocks.

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

NASA Technical Reports Server (NTRS)

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

2006-01-01

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.

Experimental BCAS Performance Results

DOT National Transportation Integrated Search

1978-07-01

The results of the (Litchford) Beacon-based Collision Avoidance System concept feasibility evaluation are reported. Included are a description of the concept, analysis and flight test results. The system concept is based on the range and bearing meas...

Experimental and simulational result multipactors in 112 MHz QWR injector

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

Xin, T.; Ben-Zvi, I.; Belomestnykh, S.

2015-05-03

The first RF commissioning of 112 MHz QWR superconducting electron gun was done in late 2014. The coaxial Fundamental Power Coupler (FPC) and Cathode Stalk (stalk) were installed and tested for the first time. During this experiment, we observed several multipacting barriers at different gun voltage levels. The simulation work was done within the same range. The comparison between the experimental observation and the simulation results are presented in this paper. The observations during the test are consisted with the simulation predictions. We were able to overcome most of the multipacting barriers and reach 1.8 MV gun voltage under pulsedmore » mode after several round of conditioning processes.« less

Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures.

PubMed

Addai, Emmanuel Kwasi; Gabel, Dieter; Krause, Ulrich

2016-04-15

The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. Copyright © 2016 Elsevier B.V. All rights reserved.

Relationships between lattice energies of inorganic ionic solids

NASA Astrophysics Data System (ADS)

Kaya, Savaş

2018-06-01

Lattice energy, which is a measure of the stabilities of inorganic ionic solids, is the energy required to decompose a solid into its constituent independent gaseous ions. In the present work, the relationships between lattice energies of many diatomic and triatomic inorganic ionic solids are revealed and a simple rule that can be used for the prediction of the lattice energies of inorganic ionic solids is introduced. According to this rule, the lattice energy of an AB molecule can be predicted with the help of the lattice energies of AX, BY and XY molecules in agreement with the experimental data. This rule is valid for not only diatomic molecules but also triatomic molecules. The lattice energy equations proposed in this rule provides compatible results with previously published lattice energy equations by Jenkins, Kaya, Born-Lande, Born-Mayer, Kapustinskii and Reddy. For a large set of tested molecules, calculated percent standard deviation values considering experimental data and the results of the equations proposed in this work are in general between %1-2%.

Recent experimental results of KSTAR RF heating and current drive

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

Wang, S. J., E-mail: sjwang@nfri.re.kr; Kim, J.; Jeong, J. H.

2015-12-10

The overview of KSTAR activities on ICRH, LHCD and ECH/CD including the last experimental results and future plan aiming for long-pulse high-beta plasma will be presented. Recently we achieved reasonable coupling of ICRF power to H-mode plasma through several efforts to increase system reliability. Power balance will be discussed on this experiment. LHCD is still struggling in the low power regime. Review of antenna spectrum for the higher coupling in H-mode plasma will be tried. ECH/CD provides 41 sec, 0.8 MW of heating power to support high-performance long-pulse discharge. Also, 170 GHz ECH system is integrated with the Plasma Control Systemmore » (PCS) for the feedback controlling of NTM. Status and plan of ECH/CD will be discussed. Finally, helicon current drive is being prepared for the next stage of KSTAR operation. The hardware preparation and the calculation results of helicon current drive in KSTAR plasma will be discussed.« less

Recent experimental results of KSTAR RF heating and current drive

NASA Astrophysics Data System (ADS)

Wang, S. J.; Kim, J.; Jeong, J. H.; Kim, H. J.; Joung, M.; Bae, Y. S.; Kwak, J. G.

2015-12-01

The overview of KSTAR activities on ICRH, LHCD and ECH/CD including the last experimental results and future plan aiming for long-pulse high-beta plasma will be presented. Recently we achieved reasonable coupling of ICRF power to H-mode plasma through several efforts to increase system reliability. Power balance will be discussed on this experiment. LHCD is still struggling in the low power regime. Review of antenna spectrum for the higher coupling in H-mode plasma will be tried. ECH/CD provides 41 sec, 0.8 MW of heating power to support high-performance long-pulse discharge. Also, 170 GHz ECH system is integrated with the Plasma Control System (PCS) for the feedback controlling of NTM. Status and plan of ECH/CD will be discussed. Finally, helicon current drive is being prepared for the next stage of KSTAR operation. The hardware preparation and the calculation results of helicon current drive in KSTAR plasma will be discussed.

Shuttle Upper Atmosphere Mass Spectrometer Experimental Flight Results

NASA Technical Reports Server (NTRS)

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

1994-01-01

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.

Computer usage and national energy consumption: Results from a field-metering study

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

Desroches, Louis-Benoit; Fuchs, Heidi; Greenblatt, Jeffery

The electricity consumption of miscellaneous electronic loads (MELs) in the home has grown in recent years, and is expected to continue rising. Consumer electronics, in particular, are characterized by swift technological innovation, with varying impacts on energy use. Desktop and laptop computers make up a significant share of MELs electricity consumption, but their national energy use is difficult to estimate, given uncertainties around shifting user behavior. This report analyzes usage data from 64 computers (45 desktop, 11 laptop, and 8 unknown) collected in 2012 as part of a larger field monitoring effort of 880 households in the San Francisco Baymore » Area, and compares our results to recent values from the literature. We find that desktop computers are used for an average of 7.3 hours per day (median = 4.2 h/d), while laptops are used for a mean 4.8 hours per day (median = 2.1 h/d). The results for laptops are likely underestimated since they can be charged in other, unmetered outlets. Average unit annual energy consumption (AEC) for desktops is estimated to be 194 kWh/yr (median = 125 kWh/yr), and for laptops 75 kWh/yr (median = 31 kWh/yr). We estimate national annual energy consumption for desktop computers to be 20 TWh. National annual energy use for laptops is estimated to be 11 TWh, markedly higher than previous estimates, likely reflective of laptops drawing more power in On mode in addition to greater market penetration. This result for laptops, however, carries relatively higher uncertainty compared to desktops. Different study methodologies and definitions, changing usage patterns, and uncertainty about how consumers use computers must be considered when interpreting our results with respect to existing analyses. Finally, as energy consumption in On mode is predominant, we outline several energy savings opportunities: improved power management (defaulting to low-power modes after periods of inactivity as well as power scaling), matching the rated

The energy balance study: the design and baseline results for a longitudinal study of energy balance.

PubMed

Hand, Gregory A; Shook, Robin P; Paluch, Amanda E; Baruth, Meghan; Crowley, E Patrick; Jaggers, Jason R; Prasad, Vivek K; Hurley, Thomas G; Hebert, James R; O'Connor, Daniel P; Archer, Edward; Burgess, Stephanie; Blair, Steven N

2013-09-01

The Energy Balance Study (EBS) was a comprehensive study designed to determine over a period of 12 months the associations of caloric intake and energy expenditure on changes in body weight and composition in a population of healthy men and women. EBS recruited men and women aged 21 to 35 years with a body mass index between 20 and 35 kg/m2. Measurements of energy intake and multiple objective measures of energy expenditure, as well as other physiological, anthropomorphic and psychosocial measurements, were made quarterly. Resting metabolic rate and blood chemistry were measured at baseline, 6 and 12 months. Four hundred and thirty (218 women and 212 men) completed all baseline measurements. There were statistically significant differences by sex uncovered for most anthropomorphic, physiological and behavioral variables. Only percent of kcals from fat and alcohol intake, as well as energy expenditure in light activity and very vigorous activity were not different. Self-reported weight change (mean +/- SD) over the previous year were 0.92 +/- 5.24 kg for women and--1.32 +/- 6.1 kg for men. Resting metabolic rate averages by sex were 2.88 +/- 0.35 ml/kg/min for women and 3.05 +/- 0.33 ml/kg/min for men. Results from EBS will inform our understanding of the impact of energy balance components as they relate to changes in body weight and composition. Initial findings suggest a satisfactory distribution of weight change to allow for robust statistical analyses. Resting metabolic rates well below the standard estimate suggest that the evaluation of the components of total energy expenditure will be impactful for our understanding of the roles of energy intake and expenditure on changes in energy utilization and storage.

Improvements in magnetic bearing performance for flywheel energy storage

NASA Technical Reports Server (NTRS)

Plant, David P.; Anand, Davinder K.; Kirk, James A.; Calomeris, Anthony J.; Romero, Robert L.

1988-01-01

The paper considers the development of a 500-Watt-hour magnetically suspended flywheel stack energy storage system. The work includes hardware testing results from a stack flywheel energy storage system, improvements in the area of noncontacting displacement transducers, and performance enhancements of magnetic bearings. Experimental results show that a stack flywheel energy storage system is feasible technology.

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

NASA Astrophysics Data System (ADS)

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

2014-07-01

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.

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

NASA Technical Reports Server (NTRS)

Akin, David L.

1987-01-01

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.

Experimental validation of a multi-energy x-ray adapted scatter separation method

NASA Astrophysics Data System (ADS)

Sossin, A.; Rebuffel, V.; Tabary, J.; Létang, J. M.; Freud, N.; Verger, L.

2016-12-01

Both in radiography and computed tomography (CT), recently emerged energy-resolved x-ray photon counting detectors enable the identification and quantification of individual materials comprising the inspected object. However, the approaches used for these operations require highly accurate x-ray images. The accuracy of the images is severely compromised by the presence of scattered radiation, which leads to a loss of spatial contrast and, more importantly, a bias in radiographic material imaging and artefacts in CT. The aim of the present study was to experimentally evaluate a recently introduced partial attenuation spectral scatter separation approach (PASSSA) adapted for multi-energy imaging. For this purpose, a prototype x-ray system was used. Several radiographic acquisitions of an anthropomorphic thorax phantom were performed. Reference primary images were obtained via the beam-stop (BS) approach. The attenuation images acquired from PASSSA-corrected data showed a substantial increase in local contrast and internal structure contour visibility when compared to uncorrected images. A substantial reduction of scatter induced bias was also achieved. Quantitatively, the developed method proved to be in relatively good agreement with the BS data. The application of the proposed scatter correction technique lowered the initial normalized root-mean-square error (NRMSE) of 45% between the uncorrected total and the reference primary spectral images by a factor of 9, thus reducing it to around 5%.

Experimental Studies of Light-Ion Nuclear Reactions Using Low-Energy RI Beams

NASA Astrophysics Data System (ADS)

Yamaguchi, H.; Kahl, D.; Hayakawa, S.; Sakaguchi, Y.; Abe, K.; Shimuzu, H.; Wakabayashi, Y.; Hashimoto, T.; Cherubini, S.; Gulino, M.; Spitaleri, C.; Rapisarda, G. G.; La Cognata, M.; Lamia, L.; Romano, S.; Kubono, S.; Iwasa, N.; Teranishi, T.; Kawabata, T.; Kwon, Y. K.; Binh, D. N.; Khiem, L. H.; Duy, N. N.; Kato, S.; Komatsubara, T.; Coc, A.; de Sereville, N.; Hammache, F.; Kiss, G.; Bishop, S.

CRIB (CNS Radio-Isotope Beam separator) is a low-energy RI beam separator of Center for Nuclear Study (CNS), the University of Tokyo. Studies on nuclear astrophysics, nuclear structure, and other interests have been performed using the RI beams at CRIB, forming international collaborations. A striking method to study astrophyiscal reactions involving radioactive nuclei is the thick-target method in inverse kinematics. Several astrophysical alpha-induced reactions have been be studied with that method at CRIB. A recent example is on the α resonant scattering with a radioactive 7Be beam. This study is related to the astrophysical 7Be(α , γ ) reactions, important at hot p-p chain and ν p-process in supernovae. There have been measurements based on several indirect methods, such as the asymptotic normalization coefficient (ANC) and Trojan horse method (THM). The first THM measurement using an RI beam has been performed at CRIB, to study the 18F(p, α )15O reaction at astrophysical energies via the three body reaction 2H(18F, α 15O)n. The 18F(p, α )15O reaction rate is crucial to understand the 511-keV γ -ray production in nova explosion phenomena, and we successfully evaluated the reaction cross section at novae temperature and below experimentally for the first time.

Short-term overeating results in incomplete energy intake compensation regardless of energy density or macronutrient composition.

PubMed

Apolzan, John W; Bray, George A; Hamilton, Marc T; Zderic, Theodore W; Han, Hongmei; Champagne, Catherine M; Shepard, Desti; Martin, Corby K

2014-01-01

To evaluate the effects of overeating (140% of energy requirements) a high-fat low-energy density diet (HF/LED, 1.05 kcal/g), high-fat high-energy density diet (HF/HED, 1.60 kcal/g), and high-carbohydrate (HC) LED (1.05 kcal/g) for 2-days on subsequent 4-day energy intake (EI), activity levels, appetite, and mood. Using a randomized cross-over design, energy expenditure and EI were standardized during overeating. In 20 adults with a mean ± SD BMI of 30.7 ± 4.6 kg/m(2) , EI was not suppressed until the second day after overeating and accounted for ∼30% of the excess EI. Reductions in EI did not differ among the three diets or across days. Overeating had no effect on subsequent energy expenditure but steps/day decreased after the HC/LED and HF/HED. Sleep time was increased after the HF/HED compared to both LEDs. After overeating a HF/HED vs. HF/LED, carbohydrate cravings, hunger, prospective food consumption, and sadness increased and satisfaction, relaxation, and tranquility decreased. Diet type, time, or their interaction had no impact on compensation over 4 days. No adaptive thermogenesis was observed. The HF/HED vs. HF/LED had detrimental effects on food cravings, appetite, and mood. These results suggest short-term overeating is associated with incomplete compensation. Copyright © 2013 The Obesity Society.

An Experimental Study in Determining Energy Expenditure from Treadmill Walking using Hip-Worn Inertial Sensors

PubMed Central

Vathsangam, Harshvardhan; Emken, Adar; Schroeder, E. Todd; Spruijt-Metz, Donna; Sukhatme, Gaurav S.

2011-01-01

This paper describes an experimental study in estimating energy expenditure from treadmill walking using a single hip-mounted triaxial inertial sensor comprised of a triaxial accelerometer and a triaxial gyroscope. Typical physical activity characterization using accelerometer generated counts suffers from two drawbacks - imprecison (due to proprietary counts) and incompleteness (due to incomplete movement description). We address these problems in the context of steady state walking by directly estimating energy expenditure with data from a hip-mounted inertial sensor. We represent the cyclic nature of walking with a Fourier transform of sensor streams and show how one can map this representation to energy expenditure (as measured by V O2 consumption, mL/min) using three regression techniques - Least Squares Regression (LSR), Bayesian Linear Regression (BLR) and Gaussian Process Regression (GPR). We perform a comparative analysis of the accuracy of sensor streams in predicting energy expenditure (measured by RMS prediction accuracy). Triaxial information is more accurate than uniaxial information. LSR based approaches are prone to outlier sensitivity and overfitting. Gyroscopic information showed equivalent if not better prediction accuracy as compared to accelerometers. Combining accelerometer and gyroscopic information provided better accuracy than using either sensor alone. We also analyze the best algorithmic approach among linear and nonlinear methods as measured by RMS prediction accuracy and run time. Nonlinear regression methods showed better prediction accuracy but required an order of magnitude of run time. This paper emphasizes the role of probabilistic techniques in conjunction with joint modeling of triaxial accelerations and rotational rates to improve energy expenditure prediction for steady-state treadmill walking. PMID:21690001

Comment on ``Experimental Free Energy Reconstruction From Single-Molecule Force Spectroscopy Using Jarzynski's Equality''

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

Friddle, R W

2008-01-14

Harris, Song and Kiang [1] (HSK) describe their results on reconstructing the free energy profiles for both the stretch of the titin polymer, and the unfolding of an individual I27 domain. The new finding reported in [1] is the measurement of the free energy barrier (or activation energy) to unfolding the I27 domain. Due to a misinterpretation of the mechanics involved, the free energy surface (and thus the energy barrier) to unfolding the I27 domain was not measured.

Experimental Investigation for 100-Joule-class TEA CO2 Laser and Gas Interaction

NASA Astrophysics Data System (ADS)

Dou, Zhiguo; Yao, Honglin; Wang, Jun; Wen, Ming; Wang, Peng; Yang, Jan; Li, Chong

2006-05-01

Impulse coupling coefficient Cm is one of the most important performance parameters in laser propulsion. Cm is the impulse increment of lightcraft that per joule laser beam energy acts on. The TEA CO2 laser, whose single pulse energy is 100-Joule-class and wavelength is 10.6μm, is adopted by experimental research. In experimental environment cabin, the parabolic lightcraft is fixed on impact pendulum. Using Air, N2, He, CO2, N2-He and N2-CO2, different Cm is obtained. Experimental results indicate that Cm of the mixed gas is improved through changing gas component ratio.

Experimental analysis of mechanical joints strength by means of energy dissipation

NASA Astrophysics Data System (ADS)

Wolf, Alexander; Lafarge, Remi; Kühn, Tino; Brosius, Alexander

2018-05-01

Designing complex structures with the demand for weight reduction leads directly to a multi-material concept. This mixture has to be joined securely and welding, mechanical joining and the usage of adhesives are commonly used for that purpose. Sometimes also a mix of at least two materials is useful to combine the individual advantages. The challenge is the non-destructive testing of these connections because destructive testing requires a lot of preparation and expensive testing equipment. The authors show a testing method by measuring and analysing the energy dissipation in mechanical joints. Known methods are radiography, thermography and ultrasound testing. Unfortunately, the usage of these methods is difficult and often not usable in fibre-reinforced-plastics. The presented approach measures the propagation of the elastic strain wave through the joint. A defined impact strain is detected with by strain-gauges whereby the transmitter is located on one side of the joint and the receiver on the other, respectively. Because of different mechanisms, energy dissipates by passing the joint areas. Main reasons are damping caused by friction and material specific damping. Insufficient performed joints lead to an effect especially in the friction damping. By the measurement of the different strains and the resulting energy loss a statement to the connection quality is given. The possible defect during the execution of the joint can be identified by the energy loss and strain vs. time curve. After the description of the method, the authors present the results of energy dissipation measurements at a bolted assembly with different locking torques. By the adjustable tightening torques for the screw connections easily a variation of the contact pressure can be applied and analysed afterwards. The outlook will give a statement for the usability for other mechanical joints and fibre-reinforced-plastics.

Energy Efficiency Feasibility Study and Resulting Plan for the Bay Mills Indian Community

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

Kushman, Chris

In 2011 the Inter-Tribal Council of Michigan, Inc. was awarded an Energy Efficiency Development and Deployment in Indian Country grant from the U.S. Department of Energy’s Tribal Energy Program. This grant aimed to study select Bay Mills Indian Community community/government buildings to determine what is required to reduce each building’s energy consumption by 30%. The Bay Mills Indian Community (BMIC) buildings with the largest expected energy use were selected for this study and included the Bay Mills Ellen Marshall Health Center building, Bay Mills Indian Community Administration Building, Bay Mills Community College main campus, Bay Mills Charter School and themore » Waishkey Community Center buildings. These five sites are the largest energy consuming Community buildings and comprised the study area of this project titled “Energy Efficiency Feasibility Study and Resulting Plan for the Bay Mills Indian Community”. The end objective of this study, plan and the Tribe is to reduce the energy consumption at the Community’s most energy intensive buildings that will, in turn, reduce emissions at the source of energy production, reduce energy expenditures, create long lasting energy conscious practices and positively affect the quality of the natural environment. This project’s feasibility study and resulting plan is intended to act as a guide to the Community’s first step towards planned energy management within its buildings/facilities. It aims to reduce energy consumption by 30% or greater within the subject facilities with an emphasis on energy conservation and efficiency. The energy audits and related power consumption analyses conducted for this study revealed numerous significant energy conservation and efficiency opportunities for all of the subject sites/buildings. In addition, many of the energy conservation measures require no cost and serve to help balance other measures requiring capital investment. Reoccurring deficiencies relating to

Primary experimental results of wire-array Z-pinches on PTS

NASA Astrophysics Data System (ADS)

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

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 μm 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.

Energy Monitoring in Gins - 2012 Preliminary Results

USDA-ARS?s Scientific Manuscript database

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...

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

NASA Technical Reports Server (NTRS)

Somers, D. M.

1981-01-01

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.

Design and Experimental Results for the S825 Airfoil; Period of Performance: 1998-1999

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

Somers, D. M.

2005-01-01

A 17%-thick, natural-laminar-flow airfoil, the S825, for the 75% blade radial station of 20- to 40-meter, variable-speed and variable-pitch (toward feather), horizontal-axis wind turbines has been designed and analyzed theoretically and verified experimentally in the NASA Langley Low-Turbulence Pressure Tunnel. The two primary objectives of high maximum lift, relatively insensitive to roughness and low-profile drag have been achieved. The airfoil exhibits a rapid, trailing-edge stall, which does not meet the design goal of a docile stall. The constraints on the pitching moment and the airfoil thickness have been satisfied. Comparisons of the theoretical and experimental results generally show good agreement.

First experimental results on the kinetic processes in a surface-wave-sustained argon discharge at atmospheric pressure

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

Calzada, M.D.; Gamero, A.; Sola, A.

1995-12-31

This communication presents an advance of the results of an experimental study of the kinetic processes in a surface-wave-sustained argon discharge at atmospheric pressure. We utilize the study developed by Fujimoto on the population and depopulation processes of the excited levels of atoms and ions. This theory has been applied by S. Daviaud and A. Hirabayashi to explain the kinetic processes in helium plasma at low pressure. Fujimoto has studied the ionization and recombination mechanisms of the plasma under various conditions and its relation to the population density distributions. This study establishes, for an hydrogenic ion with a core chargemore » z, different zones in the atomic system (level map). Each zone is characterized by the dominant mechanisms of the population and depopulation of their excited levels, A level is characterized for the effective principal quantum number p, where p = z (E{sub H}/{vert_bar}E{sub p}{vert_bar}){sup 1/2}, E{sub H} is the hydrogen ionization energy and {vert_bar}E{sub p}{vert_bar} is the energy required to ionize the atom from the level considered. The population of each level p can be expressed in terms of the parameter b(p) defined as n(p)/n{sup SB}(p), n(p) and n{sup SB}(p) being the actual population and the Saha-Boltzmann equilibrium population of the level, respectively. Figure I shows the population and depopulation processes of a level p, which are both collisional and radiative that are characterized by their respective coefficients.« less

Sustaining high-energy orbits of bi-stable energy harvesters by attractor selection

NASA Astrophysics Data System (ADS)

Udani, Janav P.; Arrieta, Andres F.

2017-11-01

Nonlinear energy harvesters have the potential to efficiently convert energy over a wide frequency range; however, difficulties in attaining and sustaining high-energy oscillations restrict their applicability in practical scenarios. In this letter, we propose an actuation methodology to switch the state of bi-stable harvesters from the low-energy intra-well configuration to the coexisting high-energy inter-well configuration by controlled phase shift perturbations. The strategy is designed to introduce a change in the system state without creating distinct metastable attractors by exploiting the basins of attraction of the coexisting stable attractors. Experimental results indicate that the proposed switching strategy yields a significant improvement in energy transduction capabilities, is highly economical, enabling the rapid recovery of energy spent in the disturbance, and can be practically implemented with widely used low-strain piezoelectric transducers.

Experimental and theoretical investigation of relative optical band gaps in graphene generations

NASA Astrophysics Data System (ADS)

Bhatnagar, Deepika; Singh, Sukhbir; Yadav, Sriniwas; Kumar, Ashok; Kaur, Inderpreet

2017-01-01

Size and chemical functionalization dependant optical band gaps in graphene family nanomaterials were investigated by experimental and theoretical study using Tauc plot and density functional theory (DFT). We have synthesized graphene oxide through a modified Hummer’s method using graphene nanoplatelets and sequentially graphene quantum dots through hydrothermal reduction. The experimental results indicate that the optical band gap in graphene generations was altered by reducing the size of graphene sheets and attachment of chemical functionalities like epoxy, hydroxyl and carboxyl groups plays a crucial role in varying optical band gaps. It is further confirmed by DFT calculations that the π orbitals were more dominatingly participating in transitions shown by projected density of states and the molecular energy spectrum represented the effect of attached functional groups along with discreteness in energy levels. Theoretical results were found to be in good agreement with experimental results. All of the above different variants of graphene can be used in native or modified form for sensor design and optoelectronic applications.

A Galloping Energy Harvester with Attached Flow

NASA Astrophysics Data System (ADS)

Denissenko, Petr; Khovanov, Igor; Tucker-Harvey, Sam

2017-11-01

Aeroelastic energy harvesters are a promising technology for the operation of wireless sensors and microelectromechanical systems, as well as providing the possibility of harvesting wind energy in applications were conventional wind turbines are ineffective, such as in highly turbulent flows, or unreliable, such as in harsh environmental conditions. The development of aeroelastic energy harvesters to date has focused on the flutter of airfoils, the galloping of prismatic structures, and the vortex induced vibrations. We present a novel type of galloping energy harvester with the flow becoming attached when the oscillation amplitude is high enough. With the flow attached, the harvester blade acts closer to an aerofoil than a bluff body, which results in a higher efficiency. The dynamics of a prototype device has been characterised experimentally with the use of a motion tracking system. The flow structure in the vicinity of the device has been studied using smoke visualisation and PIV measurements. A lumped parameter mathematical model has been developed and related to the experimental results.

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

NASA Technical Reports Server (NTRS)

Smith-Taylor, Rudeen; Tanner, Sharon E.

1993-01-01

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.

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

NASA Technical Reports Server (NTRS)

Curtis, S. B.

1994-01-01

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.

Surface symmetry energy of nuclear energy density functionals

NASA Astrophysics Data System (ADS)

Nikolov, N.; Schunck, N.; Nazarewicz, W.; Bender, M.; Pei, J.

2011-03-01

We study the bulk deformation properties of the Skyrme nuclear energy density functionals (EDFs). Following simple arguments based on the leptodermous expansion and liquid drop model, we apply the nuclear density functional theory to assess the role of the surface symmetry energy in nuclei. To this end, we validate the commonly used functional parametrizations against the data on excitation energies of superdeformed band heads in Hg and Pb isotopes and fission isomers in actinide nuclei. After subtracting shell effects, the results of our self-consistent calculations are consistent with macroscopic arguments and indicate that experimental data on strongly deformed configurations in neutron-rich nuclei are essential for optimizing future nuclear EDFs. The resulting survey provides a useful benchmark for further theoretical improvements. Unlike in nuclei close to the stability valley, whose macroscopic deformability hangs on the balance of surface and Coulomb terms, the deformability of neutron-rich nuclei strongly depends on the surface symmetry energy; hence, its proper determination is crucial for the stability of deformed phases of the neutron-rich matter and description of fission rates for r-process nucleosynthesis.

Experimental Clocking of Nanomagnets with Strain for Ultralow Power Boolean Logic.

PubMed

D'Souza, Noel; Salehi Fashami, Mohammad; Bandyopadhyay, Supriyo; Atulasimha, Jayasimha

2016-02-10

Nanomagnetic implementations of Boolean logic have attracted attention because of their nonvolatility and the potential for unprecedented overall energy-efficiency. Unfortunately, the large dissipative losses that occur when nanomagnets are switched with a magnetic field or spin-transfer-torque severely compromise the energy-efficiency. Recently, there have been experimental reports of utilizing the Spin Hall effect for switching magnets, and theoretical proposals for strain induced switching of single-domain magnetostrictive nanomagnets, that might reduce the dissipative losses significantly. Here, we experimentally demonstrate, for the first time that strain-induced switching of single-domain magnetostrictive nanomagnets of lateral dimensions ∼200 nm fabricated on a piezoelectric substrate can implement a nanomagnetic Boolean NOT gate and steer bit information unidirectionally in dipole-coupled nanomagnet chains. On the basis of the experimental results with bulk PMN-PT substrates, we estimate that the energy dissipation for logic operations in a reasonably scaled system using thin films will be a mere ∼1 aJ/bit.

Energy: Machines, Science (Experimental): 5311.03.

ERIC Educational Resources Information Center

Castaldi, June P.

This unit of instruction was designed as an introductory course in energy involving six simple machines, electricity, magnetism, and motion. The booklet lists the relevant state-adopted texts and states the performance objectives for the unit. It provides an outline of the course content and suggests experiments, demonstrations, field trips, and…

Experimental measurement of radiological penumbra associated with intermediate energy x-rays (1 MV) and small radiosurgery field sizes

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

Keller, Brian M.; Beachey, David J.; Pignol, Jean-Philippe

2007-10-15

Stereotactic radiosurgery is used to treat intracranial lesions with a high degree of accuracy. At the present time, x-ray energies at or above Co-60 gamma rays are used. Previous Monte Carlo simulations have demonstrated that intermediate energy x-ray photons or IEPs (defined to be photons in the energy range of 0.2-1.2 MeV), combined with small field sizes, produce a reduced radiological penumbra leading to a sharper dose gradient, improved dose homogeneity and sparing of critical anatomy adjacent to the target volume. This hypothesis is based on the fact that, for small x-ray fields, a dose outside the treatment volume ismore » dictated mainly by the range of electrons set into motion by x-ray photons. The purpose of this work is: (1) to produce intermediate energy x rays using a detuned medical linear accelerator (2) to characterize the energy of this beam (3) to measure the radiological penumbra for IEPs and small fields to compare with that produced by 6 MV x rays or Co-60, and (4) to compare these experimental measurements with Monte Carlo computer simulations. The maximum photon energy of our IEP x-ray spectrum was measured to be 1.2 MeV. Gafchromic EBT films (ISP Technologies, Wayne, NJ) were irradiated and read using a novel digital microscopy imaging system with high spatial resolution. Under identical irradiation conditions the measured radiological penumbra widths (80%-20% distance), for field sizes ranging from 0.3x0.3 to 4.0x4.0 cm{sup 2}, varied from 0.3-0.77 mm (1.2 MV) and from 1.1-2.1 mm (6 MV). Even more dramatic were the differences found when comparing the 90%-10% or the 95%-5% widths, which are in fact more significant in radiotherapy. Monte Carlo simulations agreed well with the experimental findings. The reduction in radiological penumbra could be substantial for specific clinical situations such as in the treatment of an ocular melanoma abutting the macula or for the treatment of functional disorders such as trigeminal neuralgia (a

Automated detection of discourse segment and experimental types from the text of cancer pathway results sections.

PubMed

Burns, Gully A P C; Dasigi, Pradeep; de Waard, Anita; Hovy, Eduard H

2016-01-01

Automated machine-reading biocuration systems typically use sentence-by-sentence information extraction to construct meaning representations for use by curators. This does not directly reflect the typical discourse structure used by scientists to construct an argument from the experimental data available within a article, and is therefore less likely to correspond to representations typically used in biomedical informatics systems (let alone to the mental models that scientists have). In this study, we develop Natural Language Processing methods to locate, extract, and classify the individual passages of text from articles' Results sections that refer to experimental data. In our domain of interest (molecular biology studies of cancer signal transduction pathways), individual articles may contain as many as 30 small-scale individual experiments describing a variety of findings, upon which authors base their overall research conclusions. Our system automatically classifies discourse segments in these texts into seven categories (fact, hypothesis, problem, goal, method, result, implication) with an F-score of 0.68. These segments describe the essential building blocks of scientific discourse to (i) provide context for each experiment, (ii) report experimental details and (iii) explain the data's meaning in context. We evaluate our system on text passages from articles that were curated in molecular biology databases (the Pathway Logic Datum repository, the Molecular Interaction MINT and INTACT databases) linking individual experiments in articles to the type of assay used (coprecipitation, phosphorylation, translocation etc.). We use supervised machine learning techniques on text passages containing unambiguous references to experiments to obtain baseline F1 scores of 0.59 for MINT, 0.71 for INTACT and 0.63 for Pathway Logic. Although preliminary, these results support the notion that targeting information extraction methods to experimental results could provide

Beta decay and the origins of biological chirality - Experimental results

NASA Technical Reports Server (NTRS)

Gidley, D. W.; Rich, A.; Van House, J.; Zitzewitz, P. W.

1982-01-01

Preliminary experimental results are presented of an investigation of the possible role of preferential radiolysis by electrons emitted in the beta decay of radionuclides, a parity-nonconserving process, in the universal causation of the optical activity of biological compounds. Experiments were designed to measure the asymmetry in the production of triplet positronium upon the bombardment of an amino acid powder target by a collimated beam of positrons as positron helicity or target chirality is reversed. No asymmetry down to a level of 0.0007 is found in experiments on the D and L forms of cystine and tryptophan, indicating an asymmetry in positronium formation cross section of less than 0.01, while an asymmetry of 0.0031 is found for leucine, corresponding to a formation cross section asymmetry of about 0.04

Solving and Learning Soft Temporal Constraints: Experimental Setting and Results

NASA Technical Reports Server (NTRS)

Rossi, F.; Sperduti, A.; Venable, K. B.; Khatib, L.; Morris, P.; Morris, R.; Clancy, Daniel (Technical Monitor)

2002-01-01

Soft temporal constraints problems allow to describe in a natural way scenarios where events happen over time and preferences are associated to event distances and durations. However, sometimes such local preferences are difficult to set, and it may be easier instead to associate preferences to some complete solutions of the problem. Machine learning techniques can be useful in this respect. In this paper we describe two solvers (one more general and the other one more efficient) for tractable subclasses of soft temporal problems, and we show some experimental results. The random generator used to build the problems on which tests are performed is also described. We also compare the two solvers highlighting the tradeoff between performance and representational power. Finally, we present a learning module and we show its behavior on randomly-generated examples.

Thermodynamically consistent relations involving plasticity, internal energy and thermal effects.

PubMed

Schreyer, H L; Maudlin, P J

2005-11-15

Experimental data associated with plastic deformations indicate that the temperature is less than that predicted from dissipation based on plastic work. To obtain reasonable correlation between theoretical and experimental results, the plastic work is often multiplied by a constant beta. This paper provides an alternative thermodynamic framework in which it is proposed that there is an additional internal energy associated with dislocation pile-up or increase in dislocation density. The form of this internal energy follows from experimental data that relates flow stress to dislocation density and to equivalent plastic strain. The result is that beta is not a constant but a derived function. Representative results for beta and temperature as functions of effective plastic strain are provided for both an uncoupled and a coupled thermoplastic theory. In addition to providing features that are believed to be representative of many metals, the formulation can be used as a basis for more advanced theories such as those needed for large deformations and general forms of internal energy.

Transient Lift-Off Test Results for an Experimental Hybrid Bearing in Air

DTIC Science & Technology

2009-12-01

High-Speed Hydrostatic Bearings,” ASME Journal of Tribology, Vol. 116, n2, 1994, pp. 337-344. [2] Scharrer, J.K., Tellier , J. and Hibbs, R., “A...J.K., Tellier , J. and Hibbs, R., “A Study of the Transient Performance of Hydrostatic Journal Bearings: Part II-Experimental Results,” STLE Paper 91...TC- 3B-2, 1991. [4] Sharrer, J., Tellier , J. and Hibbs, R., “Start Transient Testing of an Annular Hydrostatic Bearing in Liquid Oxygen,” AIAA

Design and experimental results for a flapped natural-laminar-flow airfoil for general aviation applications

NASA Technical Reports Server (NTRS)

Somers, D. M.

1981-01-01

A flapped natural laminar flow airfoil for general aviation applications, the NLF(1)-0215F, has been 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 has been achieved. The safety requirement that the maximum lift coefficient not be significantly affected with transition fixed near the leading edge has also been met. Comparisons of the theoretical and experimental results show generally good agreement.

First results of a novel Silicon Drift Detector array designed for low energy X-ray fluorescence spectroscopy

NASA Astrophysics Data System (ADS)

Rachevski, Alexandre; Ahangarianabhari, Mahdi; Bellutti, Pierluigi; Bertuccio, Giuseppe; Brigo, Elena; Bufon, Jernej; Carrato, Sergio; Castoldi, Andrea; Cautero, Giuseppe; Fabiani, Sergio; Giacomini, Gabriele; Gianoncelli, Alessandra; Giuressi, Dario; Guazzoni, Chiara; Kourousias, George; Liu, Chang; Menk, Ralf Hendrik; Montemurro, Giuseppe Vito; Picciotto, Antonino; Piemonte, Claudio; Rashevskaya, Irina; Shi, Yongbiao; Stolfa, Andrea; Vacchi, Andrea; Zampa, Gianluigi; Zampa, Nicola; Zorzi, Nicola

2016-07-01

We developed a trapezoidal shaped matrix with 8 cells of Silicon Drift Detectors (SDD) featuring a very low leakage current (below 180 pA/cm2 at 20 °C) and a shallow uniformly implanted p+ entrance window that enables sensitivity down to few hundreds of eV. The matrix consists of a completely depleted volume of silicon wafer subdivided into 4 square cells and 4 half-size triangular cells. The energy resolution of a single square cell, readout by the ultra-low noise SIRIO charge sensitive preamplifier, is 158 eV FWHM at 5.9 keV and 0 °C. The total sensitive area of the matrix is 231 mm2 and the wafer thickness is 450 μm. The detector was developed in the frame of the INFN R&D project ReDSoX in collaboration with FBK, Trento. Its trapezoidal shape was chosen in order to optimize the detection geometry for the experimental requirements of low energy X-ray fluorescence (LEXRF) spectroscopy, aiming at achieving a large detection angle. We plan to exploit the complete detector at the TwinMic spectromicroscopy beamline at the Elettra Synchrotron (Trieste, Italy). The complete system, composed of 4 matrices, increases the solid angle coverage of the isotropic photoemission hemisphere about 4 times over the present detector configuration. We report on the layout of the SDD matrix and of the experimental set-up, as well as the spectroscopic performance measured both in the laboratory and at the experimental beamline.

Energy harvesting from torsions of patterned piezoelectrics

NASA Astrophysics Data System (ADS)

Cha, Youngsu; You, Hangil

2018-03-01

In this paper, we investigate the feasibility of energy harvesting from the torsions using a piezoelectric beam. The piezoelectric beam is partially patterned and is tested in an experimental setup to force pure torsional deformation. In particular, the beam consists of two identical piezoelectric parts attached on one side of a supporting substrate. We propose a model for the energy harvesting system through the equations for a slender composite beam with the physical properties and the electromechanical coupling equations of the piezoelectric material. The theoretical predictions are validated by the comparison with the experimental results.

Energy & Man's Environment Impact Study. Summary of Results.

ERIC Educational Resources Information Center

Horsfall, J. Stuart

An evaluation was conducted on the effectiveness of Energy and Man's Environment (EME), a nonprofit energy organization which conducts energy programs in 15 states around the United States. Three research questions were addressed: (1) Who is the consumer of EME workshops and the user of EME materials? (2) How do participants view EME workshops.…

Statistical Energy Analysis (SEA) and Energy Finite Element Analysis (EFEA) Predictions for a Floor-Equipped Composite Cylinder

NASA Technical Reports Server (NTRS)

Grosveld, Ferdinand W.; Schiller, Noah H.; Cabell, Randolph H.

2011-01-01

Comet Enflow is a commercially available, high frequency vibroacoustic analysis software founded on Energy Finite Element Analysis (EFEA) and Energy Boundary Element Analysis (EBEA). Energy Finite Element Analysis (EFEA) was validated on a floor-equipped composite cylinder by comparing EFEA vibroacoustic response predictions with Statistical Energy Analysis (SEA) and experimental results. Statistical Energy Analysis (SEA) predictions were made using the commercial software program VA One 2009 from ESI Group. The frequency region of interest for this study covers the one-third octave bands with center frequencies from 100 Hz to 4000 Hz.

Experimental and numerical study of latent heat thermal energy storage systems assisted by heat pipes for concentrated solar power application

NASA Astrophysics Data System (ADS)

Tiari, Saeed

A desirable feature of concentrated solar power (CSP) with integrated thermal energy storage (TES) unit is to provide electricity in a dispatchable manner during cloud transient and non-daylight hours. Latent heat thermal energy storage (LHTES) offers many advantages such as higher energy storage density, wider range of operating temperature and nearly isothermal heat transfer relative to sensible heat thermal energy storage (SHTES), which is the current standard for trough and tower CSP systems. Despite the advantages mentioned above, LHTES systems performance is often limited by low thermal conductivity of commonly used, low cost phase change materials (PCMs). Research and development of passive heat transfer devices, such as heat pipes (HPs) to enhance the heat transfer in the PCM has received considerable attention. Due to its high effective thermal conductivity, heat pipe can transport large amounts of heat with relatively small temperature difference. The objective of this research is to study the charging and discharging processes of heat pipe-assisted LHTES systems using computational fluid dynamics (CFD) and experimental testing to develop a method for more efficient energy storage system design. The results revealed that the heat pipe network configurations and the quantities of heat pipes integrated in a thermal energy storage system have a profound effect on the thermal response of the system. The optimal placement of heat pipes in the system can significantly enhance the thermal performance. It was also found that the inclusion of natural convection heat transfer in the CFD simulation of the system is necessary to have a realistic prediction of a latent heat thermal storage system performance. In addition, the effects of geometrical features and quantity of fins attached to the HPs have been studied.

Sci—Fri PM: Dosimetry—05: Megavoltage electron backscatter: EGSnrc results versus 21 experiments

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

Ali, E. S. M.; The Ottawa Hospital Cancer Centre, Ottawa; Buchenberg, W.

2014-08-15

The accuracy of electron backscatter calculations at megavoltage energies is important for many medical physics applications. In this study, EGSnrc calculations of megavoltage electron backscatter (1–22 MeV) are performed and compared to the data from 21 experiments published between 1954 and 1993 for 25 single elements with atomic numbers from 3 to 92. Typical experimental uncertainties are 15%. For EGSnrc simulations, an ideal detector is assumed, and the most accurate electron physics options are employed, for a combined statistical and systematic uncertainty of 3%. The quantities compared are the backscatter coefficient and the energy spectra (in the backward hemisphere andmore » at specific detector locations). For the backscatter coefficient, the overall agreement is within ±2% in the absolute value of the backscatter coefficient (in per cent), and within 11% of the individual backscatter values. EGSnrc results are systematically on the higher end of the spread of the experimental data, which could be partially from systematic experimental errors discussed in the literature. For the energy spectra, reasonable agreement between simulations and experiments is observed, although there are significant variations in the experimental data. At the lower end of the spectra, simulations are higher than some experimental data, which could be due to reduced experimental sensitivity to lower energy electrons and/or over-estimation by EGSnrc for backscattered secondary electrons. In conclusion, overall good agreement is observed between EGSnrc backscatter calculations and experimental measurements for megavoltage electrons. There is a need for high quality experimental data for the energy spectra of backscattered electrons.« less

Direct Numerical Simulation of Liquid Nozzle Spray with Comparison to Shadowgraphy and X-Ray Computed Tomography Experimental Results

NASA Astrophysics Data System (ADS)

van Poppel, Bret; Owkes, Mark; Nelson, Thomas; Lee, Zachary; Sowell, Tyler; Benson, Michael; Vasquez Guzman, Pablo; Fahrig, Rebecca; Eaton, John; Kurman, Matthew; Kweon, Chol-Bum; Bravo, Luis

2014-11-01

In this work, we present high-fidelity Computational Fluid Dynamics (CFD) results of liquid fuel injection from a pressure-swirl atomizer and compare the simulations to experimental results obtained using both shadowgraphy and phase-averaged X-ray computed tomography (CT) scans. The CFD and experimental results focus on the dense near-nozzle region to identify the dominant mechanisms of breakup during primary atomization. Simulations are performed using the NGA code of Desjardins et al (JCP 227 (2008)) and employ the volume of fluid (VOF) method proposed by Owkes and Desjardins (JCP 270 (2013)), a second order accurate, un-split, conservative, three-dimensional VOF scheme providing second order density fluxes and capable of robust and accurate high density ratio simulations. Qualitative features and quantitative statistics are assessed and compared for the simulation and experimental results, including the onset of atomization, spray cone angle, and drop size and distribution.

Low-energy electron-impact ionization of helium

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

Schow, E.; Hazlett, K.; Childers, J. G.

2005-12-15

Normalized doubly differential cross sections for the electron-impact ionization of helium at low energies are presented. The data are taken at the incident electron energies of 26.3, 28.3, 30.3, 32.5, 34.3, 36.5, and 40.7 eV and for scattering angles of 10 deg. -130 deg. The measurements involve the use of the moveable target method developed at California State University Fullerton to accurately determine the continuum background in the energy-loss spectra. Normalization of experimental data is made on a relative scale to well-established experimental differential cross sections for excitation of the n=2 manifold of helium and then on an absolute scalemore » to the well-established total ionization cross sections of Shah et al. [J. Phys. B 21, 2751 (1988)]. Comparisons are made with available experimental data and the results of the convergent close-coupling theory.« less

Numerical Modeling of Fluorescence Emission Energy Dispersion in Luminescent Solar Concentrator

NASA Astrophysics Data System (ADS)

Li, Lanfang; Sheng, Xing; Rogers, John; Nuzzo, Ralph

2013-03-01

We present a numerical modeling method and the corresponding experimental results, to address fluorescence emission dispersion for applications such as luminescent solar concentrator and light emitting diode color correction. Previously established modeling methods utilized a statistic-thermodynamic theory (Kenard-Stepnov etc.) that required a thorough understanding of the free energy landscape of the fluorophores. Some more recent work used an empirical approximation of the measured emission energy dispersion profile without considering anti-Stokes shifting during absorption and emission. In this work we present a technique for modeling fluorescence absorption and emission that utilizes the experimentally measured spectrum and approximates the observable Frank-Condon vibronic states as a continuum and takes into account thermodynamic energy relaxation by allowing thermal fluctuations. This new approximation method relaxes the requirement for knowledge of the fluorophore system and reduces demand on computing resources while still capturing the essence of physical process. We present simulation results of the energy distribution of emitted photons and compare them with experimental results with good agreement in terms of peak red-shift and intensity attenuation in a luminescent solar concentrator. This work is supported by the DOE `Light-Material Interactions in Energy Conversion' Energy Frontier Research Center under grant DE-SC0001293.

Experimental Overview of Direct Photon Results in Heavy Ion Collisions

NASA Astrophysics Data System (ADS)

Novitzky, Norbert

2016-07-01

Direct photons are color blind probes and thus they provide unique opportunities to study the colored medium created in heavy ion collisions. There are many different sources of direct photons each probing different physics processes as the system evolves. In basic 2 → 2 processes the prompt photons from primary hard scatterings offer the most precise measurements of the outgoing parton energy in the opposite direction. In heavy ion collisions the created medium emits photons as thermal radiation, whose rate and anisotropies provide a unique prospective on the properties and evolution of the system. Recent results on direct photons from the LHC and RHIC experiments are briefly summarized in this paper.

Experimental, Theoretical and Computational Studies of Plasma-Based Concepts for Future High Energy Accelerators

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

Joshi, Chan; Mori, W.

2013-10-21

This is the final report on the DOE grant number DE-FG02-92ER40727 titled, “Experimental, Theoretical and Computational Studies of Plasma-Based Concepts for Future High Energy Accelerators.” During this grant period the UCLA program on Advanced Plasma Based Accelerators, headed by Professor C. Joshi has made many key scientific advances and trained a generation of students, many of whom have stayed in this research field and even started research programs of their own. In this final report however, we will focus on the last three years of the grant and report on the scientific progress made in each of the four tasksmore » listed under this grant. Four tasks are focused on: Plasma Wakefield Accelerator Research at FACET, SLAC National Accelerator Laboratory, In House Research at UCLA’s Neptune and 20 TW Laser Laboratories, Laser-Wakefield Acceleration (LWFA) in Self Guided Regime: Experiments at the Callisto Laser at LLNL, and Theory and Simulations. Major scientific results have been obtained in each of the four tasks described in this report. These have led to publications in the prestigious scientific journals, graduation and continued training of high quality Ph.D. level students and have kept the U.S. at the forefront of plasma-based accelerators research field.« less

NUCLEAR HEATING IN LIF DOSEMETERS IN A FUSION NEUTRON FIELD, TRIAL OF DIRECT COMPARISON OF EXPERIMENTAL AND SIMULATED RESULTS.

PubMed

Pohorecki, Wladyslaw; Obryk, Barbara

2017-09-29

The results of nuclear heating measured by means of thermoluminescent dosemeters (TLD-LiF) in a Cu block irradiated by 14 MeV neutrons are presented. The integral Cu experiment relevant for verification of copper nuclear data at neutron energies characteristic for fusion facilities was performed in the ENEA FNG Laboratory at Frascati. Five types of TLDs were used: highly photon sensitive LiF:Mg,Cu,P (MCP-N), 7LiF:Mg,Cu,P (MCP-7) and standard, lower sensitivity LiF:Mg,Ti (MTS-N), 7LiF:Mg,Ti (MTS-7) and 6LiF:Mg,Ti (MTS-6). Calibration of the detectors was performed with gamma rays in terms of air-kerma (10 mGy of 137Cs air-kerma). Nuclear heating in the Cu block was also calculated with the use of MCNP transport code Nuclear heating in Cu and air in TLD's positions was calculated as well. The nuclear heating contribution from all simulated by MCNP6 code particles including protons, deuterons, alphas tritons and heavier ions produced by the neutron interactions were calculated. A trial of the direct comparison between experimental results and results of simulation was performed. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Numerical simulation of granular flows : comparison with experimental results

NASA Astrophysics Data System (ADS)

Pirulli, M.; Mangeney-Castelnau, A.; Lajeunesse, E.; Vilotte, J.-P.; Bouchut, F.; Bristeau, M. O.; Perthame, B.

2003-04-01

Granular avalanches such as rock or debris flows regularly cause large amounts of human and material damages. Numerical simulation of granular avalanches should provide a useful tool for investigating, within realistic geological contexts, the dynamics of these flows and of their arrest phase and for improving the risk assessment of such natural hazards. Validation of debris avalanche numerical model on granular experiments over inclined plane is performed here. The comparison is performed by simulating granular flow of glass beads from a reservoir through a gate down an inclined plane. This unsteady situation evolves toward the steady state observed in the laboratory. Furthermore simulation exactly reproduces the arrest phase obtained by suddenly closing the gate of the reservoir once a thick flow has developped. The spreading of a granular mass released from rest at the top of a rough inclined plane is also investigated. The evolution of the avalanche shape, the velocity and the characteristics of the arrest phase are compared with experimental results and analysis of the involved forces are studied for various flow laws.

Characterisation of acoustic energy content in an experimental combustion chamber with and without external forcing

NASA Astrophysics Data System (ADS)

Webster, S.; Hardi, J.; Oschwald, M.

2015-03-01

The influence of injection conditions on rocket engine combustion stability is investigated for a sub-scale combustion chamber with shear coaxial injection elements and the propellant combination hydrogen-oxygen. The experimental results presented are from a series of tests conducted at subcritical and supercritical pressures for oxygen and for both ambient and cryogenic temperature hydrogen. The stability of the system is characterised by the root mean squared amplitude of dynamic combustion chamber pressure in the upper part of the acoustic spectrum relevant for high frequency combustion instabilities. Results are presented for both unforced and externally forced combustion chamber configurations. It was found that, for both the unforced and externally forced configurations, the injection velocity had the strongest influence on combustion chamber stability. Through the use of multivariate linear regression the influence of hydrogen injection temperature and hydrogen injection mass flow rate were best able to explain the variance in stability for dependence on injection velocity ratio. For unforced tests turbulent jet noise from injection was found to dominate the energy content of the signal. For the externally forced configuration a non-linear regression model was better able to predict the variance, suggesting the influence of non-linear behaviour. The response of the system to variation of injection conditions was found to be small; suggesting that the combustion chamber investigated in the experiment is highly stable.

Sociodemographic Correlates of Energy Drink Consumption With and Without Alcohol: Results of a Community Survey

PubMed Central

Berger, Lisa K.; Fendrich, Michael; Chen, Han-Yang; Arria, Amelia M.; Cisler, Ron A.

2010-01-01

Objective We examined the sociodemographic correlates of energy drink use and the differences between those who use them with and without alcohol in a representative community sample. Methods A random-digit-dial landline telephone survey of adults in the Milwaukee, Wisconsin area responded to questions about energy drink and alcohol plus energy drink use. Results Almost one-third of respondents consumed at least one energy drink in their lifetime, while slightly over 25% used energy drinks in the past year and 6% were past-year alcohol plus energy drink users. There were important racial/ethnic differences in consumption patterns. Compared to non-users, past-year energy drink users were more likely to be non-Black minorities; and past-year alcohol plus energy drink users when compared to energy drink users only were more likely to be White and younger. Alcohol plus energy drink users also were more likely to be hazardous drinkers. Conclusions Our results which are among the first from a community sample suggest a bifurcated pattern of energy drink use highlighting important population consumption differences between users of energy drinks only and those who use alcohol and energy drinks together. PMID:21276661

Cyclic Inelastic Deformation and Fatigue Resistance of a Rail Steel : Experimental Results and Mathematical Models

DOT National Transportation Integrated Search

1981-10-01

Experimental results developed from tests of uniaxial, smooth specimens obtained from the head of an unused section of rail have been reported. Testing encompassed a broad range of conditions - monotonic tension, monotonic compression, and fully reve...

Resolving Key Uncertainties in Subsurface Energy Recovery: One Role of In Situ Experimentation and URLs (Invited)

NASA Astrophysics Data System (ADS)

Elsworth, D.

2013-12-01

Significant uncertainties remain and influence the recovery of energy from the subsurface. These uncertainties include the fate and transport of long-lived radioactive wastes that result from the generation of nuclear power and have been the focus of an active network of international underground research laboratories dating back at least 35 years. However, other nascent carbon-free energy technologies including conventional and EGS geothermal methods, carbon-neutral methods such as carbon capture and sequestration and the utilization of reduced-carbon resources such as unconventional gas reservoirs offer significant challenges in their effective deployment. We illustrate the important role that in situ experiments may play in resolving behaviors at extended length- and time-scales for issues related to chemical-mechanical interactions. Significantly, these include the evolution of transport and mechanical characteristics of stress-sensitive fractured media and their influence of the long-term behavior of the system. Importantly, these interests typically relate to either creating reservoirs (hydroshearing in EGS reservoirs, artificial fractures in shales and coals) or maintaining seals at depth where the permeating fluids may include mixed brines, CO2, methane and other hydrocarbons. Critical questions relate to the interaction of these various fluid mixtures and compositions with the fractured substrate. Important needs are in understanding the roles of key processes (transmission, dissolution, precipitation, sorption and dynamic stressing) on the modification of effective stresses and their influence on the evolution of permeability, strength and induced seismicity on the resulting development of either wanted or unwanted fluid pathways. In situ experimentation has already contributed to addressing some crucial issues of these complex interactions at field scale. Important contributions are noted in understanding the fate and transport of long-lived wastes

Extension of the energy range of the experimental activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium up to 65MeV.

PubMed

Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Ignatyuk, A V

2015-04-01

Activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium were extended up to 65MeV by using stacked foil irradiation and gamma spectrometry experimental methods. Experimental cross-sections data for the formation of the radionuclides (159)Dy, (157)Dy, (155)Dy, (161)Tb, (160)Tb, (156)Tb, (155)Tb, (154m2)Tb, (154m1)Tb, (154g)Tb, (153)Tb, (152)Tb and (151)Tb are reported in the 36-65MeV energy range, and compared with an old dataset from 1964. The experimental data were also compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS nuclear reaction model code as listed in the latest on-line libraries TENDL 2013. Copyright © 2015. Published by Elsevier Ltd.

Initial development of the two-dimensional ejector shear layer - Experimental results

NASA Technical Reports Server (NTRS)

Benjamin, M. A.; Dufflocq, M.; Roan, V. P.

1993-01-01

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.

Object impedance control for cooperative manipulation - Theory and experimental results

NASA Technical Reports Server (NTRS)

Schneider, Stanley A.; Cannon, Robert H., Jr.

1992-01-01

This paper presents the dynamic control module of the Dynamic and Strategic Control of Cooperating Manipulators (DASCCOM) project at Stanford University's Aerospace Robotics Laboratory. First, the cooperative manipulation problem is analyzed from a systems perspective, and the desirable features of a control system for cooperative manipulation are discussed. Next, a control policy is developed that enforces a controlled impedance not of the individual arm endpoints, but of the manipulated object itself. A parallel implementation for a multiprocessor system is presented. The controller fully compensates for the system dynamics and directly controls the object internal forces. Most importantly, it presents a simple, powerful, intuitive interface to higher level strategic control modules. Experimental results from a dual two-link-arm robotic system are used to compare the object impedance controller with other strategies, both for free-motion slews and environmental contact.

Obturator Artery Injury Resulting in Massive Hemorrhage From a Low-Energy Pubic Ramus Fracture.

PubMed

Solarz, Mark K; Kistler, Justin M; Rehman, Saqib

2017-05-01

Pelvic ring fractures are common in the elderly population and are usually a result of low-energy trauma, such as falls from standing. In most cases, low-energy pelvic ring injuries can be treated with appropriate analgesia and early mobilization. Arterial injury resulting in hemodynamic instability from a low-energy pelvic ring injury is rare but, given the poor compliance of vessels in the elderly population, possible. These patients must be carefully monitored after the initial injury. The purpose of this report is to describe an elderly patient who sustained a superior pubic ramus fracture and arterial injury following a low-energy fall from standing that required angiographic intervention. Elderly patients who sustain low-energy or pelvic insufficiency fractures are unlike the younger population with high-energy pelvic fractures and hemodynamic collapse. Elderly patients can have a delayed presentation of arterial injury and require careful physical examination and close monitoring. Additionally, the authors provide a review of the literature for low-energy pelvic fractures. [Orthopedics. 2017; 40(3):e546-e548.]. Copyright 2017, SLACK Incorporated.

Laser long-range remote-sensing program experimental results

NASA Astrophysics Data System (ADS)

Highland, Ronald G.; Shilko, Michael L.; Fox, Marsha J.; Gonglewski, John D.; Czyzak, Stanley R.; Dowling, James A.; Kelly, Brian; Pierrottet, Diego F.; Ruffatto, Donald; Loando, Sharon; Matsuura, Chris; Senft, Daniel C.; Finkner, Lyle; Rae, Joe; Gallegos, Joe

1995-12-01

A laser long range remote sensing (LRS) program is being conducted by the United States Air Force Phillips Laboratory (AF/PL). As part of this program, AF/PL is testing the feasibility of developing a long path CO(subscript 2) laser-based DIAL system for remote sensing. In support of this program, the AF/PL has recently completed an experimental series using a 21 km slant- range path (3.05 km ASL transceiver height to 0.067 km ASL target height) at its Phillips Laboratory Air Force Maui Optical Station (AMOS) facility located on Maui, Hawaii. The dial system uses a 3-joule, (superscript 13)C isotope laser coupled into a 0.6 m diameter telescope. The atmospheric optical characterization incorporates information from an infrared scintillometer co-aligned to the laser path, atmospheric profiles from weather balloons launched from the target site, and meteorological data from ground stations at AMOS and the target site. In this paper, we report a description of the experiment configuration, a summary of the results, a summary of the atmospheric conditions and their implications to the LRS program. The capability of such a system for long-range, low-angle, slant-path remote sensing is discussed. System performance issues relating to both coherent and incoherent detection methods, atmospheric limitations, as well as, the development of advanced models to predict performance of long range scenarios are presented.

Results of Experimental Study on Flexitime and Family Life.

ERIC Educational Resources Information Center

Winett, Richard A.; Neale, Michael S.

1980-01-01

According to two small experimental studies of flexible working hours, federal workers with young children choose to arrive at and depart from work earlier, allowing them to increase the time spent with their families and to engage in recreational, educational, and household activities. (Author/SK)

Design and operating experience on the U.S. Department of Energy Experimental Mod-O 100 kW Wind Turbine

NASA Technical Reports Server (NTRS)

Glasgow, J. C.; Birchenough, A. G.

1978-01-01

The Mod-O 100 kW Experimental Wind Turbine was designed and fabricated by NASA, as part of the Federal Wind Energy Program, to assess technology requirements and engineering problems of large wind turbines. The machine became operational in October 1975 and has demonstrated successful operation in all of its design modes. During the course of its operations the machine has generated a wealth of experimental data and has served as a prototype developmental test bed for the Mod-OA operational wind turbines which are currently used on utility networks. This paper describes the mechanical and control systems as they evolved in operational tests and describes some of the experience with various systems in the downwind rotor configuration.

Refined Dummy Atom Model of Mg(2+) by Simple Parameter Screening Strategy with Revised Experimental Solvation Free Energy.

PubMed

Jiang, Yang; Zhang, Haiyang; Feng, Wei; Tan, Tianwei

2015-12-28

Metal ions play an important role in the catalysis of metalloenzymes. To investigate metalloenzymes via molecular modeling, a set of accurate force field parameters for metal ions is highly imperative. To extend its application range and improve the performance, the dummy atom model of metal ions was refined through a simple parameter screening strategy using the Mg(2+) ion as an example. Using the AMBER ff03 force field with the TIP3P model, the refined model accurately reproduced the experimental geometric and thermodynamic properties of Mg(2+). Compared with point charge models and previous dummy atom models, the refined dummy atom model yields an enhanced performance for producing reliable ATP/GTP-Mg(2+)-protein conformations in three metalloenzyme systems with single or double metal centers. Similar to other unbounded models, the refined model failed to reproduce the Mg-Mg distance and favored a monodentate binding of carboxylate groups, and these drawbacks needed to be considered with care. The outperformance of the refined model is mainly attributed to the use of a revised (more accurate) experimental solvation free energy and a suitable free energy correction protocol. This work provides a parameter screening strategy that can be readily applied to refine the dummy atom models for metal ions.

Measurements of energy distribution and thrust for microwave plasma coupling of electrical energy to hydrogen for propulsion

NASA Technical Reports Server (NTRS)

Morin, T.; Chapman, R.; Filpus, J.; Hawley, M.; Kerber, R.; Asmussen, J.; Nakanishi, S.

1982-01-01

A microwave plasma system for transfer of electrical energy to hydrogen flowing through the system has potential application for coupling energy to a flowing gas in the electrothermal propulsion concept. Experimental systems have been designed and built for determination of the energy inputs and outputs and thrust for the microwave coupling of energy to hydrogen. Results for experiments with pressure in the range 100 microns-6 torr, hydrogen flow rate up to 1000 micronmoles/s, and total absorbed power to 700 w are presented.

High energy nucleus-nucleus collisions

NASA Technical Reports Server (NTRS)

Wosiek, B.

1986-01-01

Experimental results on high energy nucleus-nucleus interactions are presented. The data are discussed within the framework of standard super-position models and from the point-of-view of the possible formation of new states of matter in heavy ion collisions.

[Navigated drilling for femoral head necrosis. Experimental and clinical results].

PubMed

Beckmann, J; Tingart, M; Perlick, L; Lüring, C; Grifka, J; Anders, S

2007-05-01

In the early stages of osteonecrosis of the femoral head, core decompression by exact drilling into the ischemic areas can reduce pain and achieve reperfusion. Using computer aided surgery, the precision of the drilling can be improved while simultaneously lowering radiation exposure time for both staff and patients. We describe the experimental and clinical results of drilling under the guidance of the fluoroscopically-based VectorVision navigation system (BrainLAB, Munich, Germany). A total of 70 sawbones were prepared mimicking an osteonecrosis of the femoral head. In two experimental models, bone only and obesity, as well as in a clinical setting involving ten patients with osteonecrosis of the femoral head, the precision and the duration of radiation exposure were compared between the VectorVision system and conventional drilling. No target was missed. For both models, there was a statistically significant difference in terms of the precision, the number of drilling corrections as well as the radiation exposure time. The average distance to the desired midpoint of the lesion of both models was 0.48 mm for navigated drilling and 1.06 mm for conventional drilling, the average drilling corrections were 0.175 and 2.1, and the radiation exposure time less than 1 s and 3.6 s, respectively. In the clinical setting, the reduction of radiation exposure (below 1 s for navigation compared to 56 s for the conventional technique) as well as of drilling corrections (0.2 compared to 3.4) was also significant. Computer guided drilling using the fluoroscopically based VectorVision navigation system shows a clearly improved precision with a enormous simultaneous reduction in radiation exposure. It is therefore recommended for clinical routine.

Reflectivity of 1D photonic crystals: A comparison of computational schemes with experimental results

NASA Astrophysics Data System (ADS)

Pérez-Huerta, J. S.; Ariza-Flores, D.; Castro-García, R.; Mochán, W. L.; Ortiz, G. P.; Agarwal, V.

2018-04-01

We report the reflectivity of one-dimensional finite and semi-infinite photonic crystals, computed through the coupling to Bloch modes (BM) and through a transfer matrix method (TMM), and their comparison to the experimental spectral line shapes of porous silicon (PS) multilayer structures. Both methods reproduce a forbidden photonic bandgap (PBG), but slowly-converging oscillations are observed in the TMM as the number of layers increases to infinity, while a smooth converged behavior is presented with BM. The experimental reflectivity spectra is in good agreement with the TMM results for multilayer structures with a small number of periods. However, for structures with large amount of periods, the measured spectral line shapes exhibit better agreement with the smooth behavior predicted by BM.

Overview of the Manitou Experimental Forest Observatory: site description and selected science results from 2008 to 2013

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

Ortega, John; Turnipseed, A.; Guenther, Alex B.

2014-01-01

The Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen (BEACHON) project seeks to understand the feedbacks and interrelationships between hydrology, biogenic emissions, carbon assimilation, aerosol properties, clouds and associated feedbacks within water-limited ecosystems. The Manitou Experimental Forest Observatory (MEFO) was established in 2008 by the National Center for Atmospheric Research to address many of the BEACHON research objectives, and it now provides a fixed field site with significant infrastructure. MEFO is a mountainous, semi-arid ponderosa pine-dominated forest site that is normally dominated by clean continental air but is periodically influenced by anthropogenic sources from Colorado Front Range cities.more » This article summarizes the past and ongoing research activities at the site, and highlights some of the significant findings that have resulted from these measurements. These activities include – soil property measurements; – hydrological studies; – measurements of high-frequency turbulence parameters; – eddy covariance flux measurements of water, energy, aerosols and carbon dioxide through the canopy; – determination of biogenic and anthropogenic volatile organic compound emissions and their influence on regional atmospheric chemistry; – aerosol number and mass distributions; – chemical speciation of aerosol particles; – characterization of ice and cloud condensation nuclei; – trace gas measurements; and – model simulations using coupled chemistry and meteorology. In addition to various long-term continuous measurements, three focused measurement campaigns with state-of-the-art instrumentation have taken place since the site was established, and two of these studies are the subjects of this special issue: BEACHON-ROCS (Rocky Mountain Organic Carbon Study, 2010) and BEACHON-RoMBAS (Rocky Mountain Biogenic Aerosol Study, 2011).« less

Experimental study of mini SCADA renewable energy management system on microgrid using Raspberry Pi

NASA Astrophysics Data System (ADS)

Tridianto, E.; Permatasari, P. D.; Ali, I. R.

2018-03-01

Renewable Energy Management System (REMS) is a device that can be able to monitor power through a microgrid. The purpose of this system is to optimize power usage that produced from renewable energy with the result that reduces power demand from the grid. To reach the goal this device manage the load power needs fully supplied by renewable energy when the power produced from renewable energy is higher than load demand, besides power surplus will be stored in battery in this way energy stored in battery can be used when it needed. When the power produced from renewable energy can not satisfy the power demand, power will supply by renewable energy and grid. This device uses power meters for record any power flow through microgrid. In order to manage power flow in microgrid this system use relay module. The user can find out energy consumption (consumed by the load) and production (produced by renewable energy) in a period of time so that the user can switch on the load in right time.

Long term effects of neonatal exposure to fluoxetine on energy balance: A systematic review of experimental studies.

PubMed

da L D Barros, Manuella; Manhães-de-Castro, Raul; Alves, Daniele T; Quevedo, Omar Guzmán; Toscano, Ana Elisa; Bonnin, Alexandre; Galindo, Ligia

2018-06-08

Serotonin exerts a modulating function on the development of the central nervous system, including hypothalamic circuits controlling feeding behavior and energy expenditure. Based on the developmental plasticity theory, early disturbances of synaptic availability of serotonin may promote phenotypic adaptations and late disorders of energy balance regulation leading to obesity and associated diseases. The aim of this systematic review is to determine the effects of pharmacological neonatal inhibition of serotonin reuptake by fluoxetine, on parameters related to feeding behavior and energy balance. Literature searches were performed in Medline/PubMed and Lilacs databases, out of which 9726 studies were found. Using predefined protocol and registered on CAMARADES website, 23 studies were included for qualitative synthesis. The internal validity was assessed using the SYRCLE's risk of bias toll. Kappa index was also measured for analyzing the concordance between the reviewers. In addition, the PRISMA statement was used for reporting this systematic review. Most of the included studies demonstrated that neonatal serotonin reuptake inhibition is associated with long term reduced body weight, lower fat mass and higher thermogenic capacity and mitochondrial oxygen consumption in key metabolic tissues. Therefore, experimental fluoxetine exposure during neonatal development may promote long-term changes related to energy balance associated with a lean phenotype. Copyright © 2018 Elsevier B.V. All rights reserved.

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

NASA Technical Reports Server (NTRS)

Cleary, Joseph W.

1989-01-01

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.

Experimental light scattering by small particles: first results with a novel Mueller matrix scatterometer

NASA Astrophysics Data System (ADS)

Penttilä, Antti; Maconi, Göran; Kassamakov, Ivan; Gritsevich, Maria; Helander, Petteri; Puranen, Tuomas; Hæggström, Edward; Muinonen, Karri

2017-06-01

We describe a setup for measuring the full angular Mueller matrix profile of a single mm- to μm-sized sample, and verify the experimental results against a theoretical model. The scatterometer has a fixed or levitating sample, illuminated with a laser beam whose full polarization state is controlled. The scattered light is detected with a combination of wave retarder, linear polarizer, and photomultiplier tube that is attached to a rotational stage. The first results are reported.

Experimental results on multi-nucleonic K- absorptions in light nuclei

NASA Astrophysics Data System (ADS)

Vázquez Doce, O.; Cargnelli, M.; Curceanu, C.; Del Grande, R.; Fabbietti, L.; Marton, J.; Piscicchia, K.; Scordo, A.; Sirghi, D.; Tucakovic, I.; Wycech, S.; Zmeskal, J.; Anastasi, A.; Curciarello, F.; Czerwinski, E.; Krzemien, W.; Mandaglio, G.; Martini, M.; Moskal, P.; Patera, V.; Perez del Rio, E.; Silarski, M.

2017-03-01

The AMADEUS collaboration studied the K- absorptions at low momentum in light nuclei leading to Σ0p final state. Those events were recorded by the KLOE detector, used as an active target, installed in the the DAΦNE collider. The results show that it is possible to isolate the process where the K- is absorbed by two nucleons and the decay products are emitted without any further final state interactions among other contributions involving more than two nucleons. Further, the possible contribution of a ppK- bound state was investigated. The best fit gives space to a yield of ppK-/Kstop- = (0.044 ± 0.009 stat-0.005+0.004) × 10-2 corresponding to a binding energy and a width of 45 and 30 MeV/c2, respectively. A statistical analysis of this result shows although that its significance is only at the level of 1σ.

Experimental and Numerical Modeling of Fluid Flow Processes in Continuous Casting: Results from the LIMMCAST-Project

NASA Astrophysics Data System (ADS)

Timmel, K.; Kratzsch, C.; Asad, A.; Schurmann, D.; Schwarze, R.; Eckert, S.

2017-07-01

The present paper reports about numerical simulations and model experiments concerned with the fluid flow in the continuous casting process of steel. This work was carried out in the LIMMCAST project in the framework of the Helmholtz alliance LIMTECH. A brief description of the LIMMCAST facilities used for the experimental modeling at HZDR is given here. Ultrasonic and inductive techniques and the X-ray radioscopy were employed for flow measurements or visualizations of two-phase flow regimes occurring in the submerged entry nozzle and the mold. Corresponding numerical simulations were performed at TUBAF taking into account the dimensions and properties of the model experiments. Numerical models were successfully validated using the experimental data base. The reasonable and in many cases excellent agreement of numerical with experimental data allows to extrapolate the models to real casting configurations. Exemplary results will be presented here showing the effect of electromagnetic brakes or electromagnetic stirrers on the flow in the mold or illustrating the properties of two-phase flows resulting from an Ar injection through the stopper rod.

RFI in hybrid loops - Simulation and experimental results.

NASA Technical Reports Server (NTRS)

Ziemer, R. E.; Nelson, D. R.; Raghavan, H. R.

1972-01-01

A digital simulation of an imperfect second-order hybrid phase-locked loop (HPLL) operating in radio frequency interference (RFI) is described. Its performance is characterized in terms of phase error variance and phase error probability density function (PDF). Monte-Carlo simulation is used to show that the HPLL can be superior to the conventional phase-locked loops in RFI backgrounds when minimum phase error variance is the goodness criterion. Similar experimentally obtained data are given in support of the simulation data.

Boston Community Information System 1986 Experimental Test Results.

DTIC Science & Technology

1987-08-01

self -selected participants have a strong technical orientation and high educational achievement. In addition, five visually impaired people use the...group. The experimental test of the system was performed on a self -selected population of computer literate volunteers. In order to simplify the test...for fat respose .’ - 1041 OI haven’t used it yet.’ - 1046 ’No modem yet. New version installed 11/2/86.0 - 1047 ’Not yet tried. Wil do so moon.’ - 1061

A multiscale-based approach for composite materials with embedded PZT filaments for energy harvesting

NASA Astrophysics Data System (ADS)

El-Etriby, Ahmed E.; Abdel-Meguid, Mohamed E.; Hatem, Tarek M.; Bahei-El-Din, Yehia A.

2014-03-01

Ambient vibrations are major source of wasted energy, exploiting properly such vibration can be converted to valuable energy and harvested to power up devices, i.e. electronic devices. Accordingly, energy harvesting using smart structures with active piezoelectric ceramics has gained wide interest over the past few years as a method for converting such wasted energy. This paper provides numerical and experimental analysis of piezoelectric fiber based composites for energy harvesting applications proposing a multi-scale modeling approach coupled with experimental verification. The multi-scale approach suggested to predict the behavior of piezoelectric fiber-based composites use micromechanical model based on Transformation Field Analysis (TFA) to calculate the overall material properties of electrically active composite structure. Capitalizing on the calculated properties, single-phase analysis of a homogeneous structure is conducted using finite element method. The experimental work approach involves running dynamic tests on piezoelectric fiber-based composites to simulate mechanical vibrations experienced by a subway train floor tiles. Experimental results agree well with the numerical results both for static and dynamic tests.

SU-F-19A-06: Experimental Investigation of the Energy Dependence of TLD Sensitivity in Low-Energy Photon Beams

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

Chen, Z; Nath, R

Purpose: To measure the energy dependence of TLD sensitivity in lowenergy photon beams with equivalent mono-energetic energy matching those of 103Pd, 125I and 131Cs brachytherapy sources. Methods: A Pantek DXT 300 x-ray unit (Precision X-ray, Branford, CT), with stable digital voltage control down to 20 kV, was used to establish three lowenergy photon beams with narrow energy spread and equivalent monoenergetic energies matching those of 103Pd, 125I and 131Cs brachytherapy sources. The low-energy x-ray beams and a reference 6 MV photon beam were calibrated according to the AAPM TG-61 and TG-51 protocols, respectively, using a parallel-plate low-energy chamber and amore » Farmer cylindrical chamber with NIST traceable calibration factors. The dose response of model TLD-100 micro-cubes (1×1×1 mm{sup 3}) in each beam was measured for five different batches of TLDs (each contained approximately 100 TLDs) that have different histories of irradiation and usage. Relative absorbed dose sensitivity was determined as the quotient of the slope of dose response for a beam-of-interest to that of the reference beam. Results: Equivalent mono-energetic photon energies of the low-energy beams established for 103Pd, 125I and 131Cs sources were 20.5, 27.5, and 30.1 keV, respectively. Each beam exhibited narrow spectral spread with energyhomogeneity index close to 90%. The relative absorbed-dose sensitivity was found to vary between different batches of TLD with maximum differences of up to 8%. The mean and standard deviation determined from the five TLD batches was 1.453 ± 0.026, 1.541 ± 0.035 and 1.529 ± 0.051 for the simulated 103P, 125I and 131Cs beams, respectively. Conclusion: Our measured relative absorbed-dose sensitivities are greater than the historically measured value of 1.41. We find that the relative absorbed-dose sensitivity of TLD in the 103P beam is approximately 5% lower than that of 125I and 131Cs beams. Comparison of our results with other studies will be

Insulator-based dielectrophoresis of microorganisms: theoretical and experimental results.

PubMed

Moncada-Hernandez, Hector; Baylon-Cardiel, Javier L; Pérez-González, Victor H; Lapizco-Encinas, Blanca H

2011-09-01

Dielectrophoresis (DEP) is the motion of particles due to polarization effects in nonuniform electric fields. DEP has great potential for handling cells and is a non-destructive phenomenon. It has been utilized for different cell analysis, from viability assessments to concentration enrichment and separation. Insulator-based DEP (iDEP) provides an attractive alternative to conventional electrode-based systems; in iDEP, insulating structures are used to generate nonuniform electric fields, resulting in simpler and more robust devices. Despite the rapid development of iDEP microdevices for applications with cells, the fundamentals behind the dielectrophoretic behavior of cells has not been fully elucidated. Understanding the theory behind iDEP is necessary to continue the progress in this field. This work presents the manipulation and separation of bacterial and yeast cells with iDEP. A computational model in COMSOL Multiphysics was employed to predict the effect of direct current-iDEP on cells suspended in a microchannel containing an array of insulating structures. The model allowed predicting particle behavior, pathlines and the regions where dielectrophoretic immobilization should occur. Experimental work was performed at the same operating conditions employed with the model and results were compared, obtaining good agreement. This is the first report on the mathematical modeling of the dielectrophoretic response of yeast and bacterial cells in a DC-iDEP microdevice. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Static properties of ferromagnetic quantum chains: Numerical results and experimental data on two S=1/2 systems (invited)

NASA Astrophysics Data System (ADS)

Kopinga, K.; Delica, T.; Leschke, H.

1990-05-01

New results of a variant of the numerically exact quantum transfer matrix method have been compared with experimental data on the static properties of [C6H11NH3]CuBr3(CHAB), a ferromagnetic system with about 5% easy-plane anisotropy. Above T=3.5 K, the available data on the zero-field heat capacity, the excess heat capacity ΔC=C(B)-C(B=0), and the magnetization are described with an accuracy comparable to the experimental error. Calculations of the spin-spin correlation functions reveal that the good description of the experimental correlation length in CHAB by a classical spin model is largely accidental. The zero-field susceptibility, which can be deduced from these correlation functions, is in fair agreement with the reported experimental data between 4 and 100 K. The method also seems to yield accurate results for the chlorine isomorph, CHAC, a system with about 2% uniaxial anisotropy.

Experimental Evaluation of a High Speed Flywheel for an Energy Cache System

NASA Astrophysics Data System (ADS)

Haruna, J.; Murai, K.; Itoh, J.; Yamada, N.; Hirano, Y.; Fujimori, T.; Homma, T.

2011-03-01

A flywheel energy cache system (FECS) is a mechanical battery that can charge/discharge electricity by converting it into the kinetic energy of a rotating flywheel, and vice versa. Compared to a chemical battery, a FECS has great advantages in durability and lifetime, especially in hot or cold environments. Design simulations of the FECS were carried out to clarify the effects of the composition and dimensions of the flywheel rotor on the charge/discharge performance. The rotation speed of a flywheel is limited by the strength of the materials from which it is constructed. Three materials, carbon fiber-reinforced polymer (CFRP), Cr-Mo steel, and a Mg alloy were examined with respect to the required weight and rotation speed for a 3 MJ (0.8 kWh) charging/discharging energy, which is suitable for an FECS operating with a 3-5 kW photovoltaic device in an ordinary home connected to a smart grid. The results demonstrate that, for a stationary 3 MJ FECS, Cr-Mo steel was the most cost-effective, but also the heaviest, Mg-alloy had a good balance of rotation speed and weight, which should result in reduced mechanical loss and enhanced durability and lifetime of the system, and CFRP should be used for applications requiring compactness and a higher energy density. Finally, a high-speed prototype FW was analyzed to evaluate its fundamental characteristics both under acceleration and in the steady state.

Experimental signature of collective enhancement in nuclear level density

NASA Astrophysics Data System (ADS)

Pandit, Deepak; Bhattacharya, Srijit; Mondal, Debasish; Roy, Pratap; Banerjee, K.; Mukhopadhyay, S.; Pal, Surajit; De, A.; Dey, Balaram; Banerjee, S. R.

2018-04-01

We present a probable experimental signature of collective enhancement in the nuclear level density (NLD) by measuring the neutron and the giant dipole resonance (GDR) γ rays emitted from the rare-earth 169Tm compound nucleus populated at 26.1 MeV excitation energy. An enhanced yield is observed in both neutron and γ -ray spectra corresponding to the same excitation energy in the daughter nuclei. The enhancement could only be reproduced by including a collective enhancement factor in the Fermi gas model of NLD to explain the neutron and GDR spectra simultaneously. The experimental results show that the relative enhancement factor is of the order of 10 and the fadeout occurs at ˜14 MeV excitation energy, much before the commonly accepted transition from deformed to spherical shape. We also explain how the collective enhancement contribution changes the inverse level density parameter k from 8 to 9.5 MeV observed recently in several deformed nuclei.

Adaptive algorithms of position and energy reconstruction in Anger-camera type detectors: experimental data processing in ANTS

NASA Astrophysics Data System (ADS)

Morozov, A.; Defendi, I.; Engels, R.; Fraga, F. A. F.; Fraga, M. M. F. R.; Gongadze, A.; Guerard, B.; Jurkovic, M.; Kemmerling, G.; Manzin, G.; Margato, L. M. S.; Niko, H.; Pereira, L.; Petrillo, C.; Peyaud, A.; Piscitelli, F.; Raspino, D.; Rhodes, N. J.; Sacchetti, F.; Schooneveld, E. M.; Solovov, V.; Van Esch, P.; Zeitelhack, K.

2013-05-01

The software package ANTS (Anger-camera type Neutron detector: Toolkit for Simulations), developed for simulation of Anger-type gaseous detectors for thermal neutron imaging was extended to include a module for experimental data processing. Data recorded with a sensor array containing up to 100 photomultiplier tubes (PMT) or silicon photomultipliers (SiPM) in a custom configuration can be loaded and the positions and energies of the events can be reconstructed using the Center-of-Gravity, Maximum Likelihood or Least Squares algorithm. A particular strength of the new module is the ability to reconstruct the light response functions and relative gains of the photomultipliers from flood field illumination data using adaptive algorithms. The performance of the module is demonstrated with simulated data generated in ANTS and experimental data recorded with a 19 PMT neutron detector. The package executables are publicly available at http://coimbra.lip.pt/~andrei/

Homestake result, sterile neutrinos, and low energy solar neutrino experiments

NASA Astrophysics Data System (ADS)

de Holanda, P. C.; Smirnov, A. Yu.

2004-06-01