Geoantineutrino spectrum and slow nuclear burning on the boundary of the liquid and solid phases of the Earth's core

NASA Astrophysics Data System (ADS)

Rusov, V. D.; Pavlovich, V. N.; Vaschenko, V. N.; Tarasov, V. A.; Zelentsova, T. N.; Bolshakov, V. N.; Litvinov, D. A.; Kosenko, S. I.; Byegunova, O. A.

2007-09-01

We give an alternative description of the data produced in the KamLAND experiment. Assuming the existence of a natural nuclear reactor on the boundary of the liquid and solid phases of the Earth's core, a geoantineutrino spectrum is obtained. This assumption is based on the experimental results of V. Anisichkin and his collaborators on the interaction of uranium dioxide and uranium carbide with iron-nickel and silica-alumina melts at high pressure (5-10 GPa) and temperature (1600-2200°C), which led to the proposal of the existence of an actinide shell in the Earth's core. We describe the operating mechanism of this reactor as solitary waves of nuclear burning in 238U and/or 232Th medium, in particular, as neutron fission progressive waves of Feoktistov and/or Teller et al. type. Next, we propose a simplified model for the accumulation and burn-up kinetics in Feoktistov's U-Pu fuel cycle. We also apply this model for numerical simulations of neutron fission wave in a two-phase UO2/Fe medium on the surface of the Earth's solid core. The proposed georeactor model offers a mechanism for the generation of 3He. The 3He/4He distribution in the Earth's interior is calculated, which in turn can be used as a natural quantitative criterion of the georeactor thermal power. Finally, we give a tentative estimation of the geoantineutrino intensity and spectrum on the Earth's surface. For this purpose we use the O'Nions et al. geochemical model of mantle differentiation and crust growth complemented by a nuclear energy source (georeactor with power of 30 TW).

Iron snow in the Martian core?

NASA Astrophysics Data System (ADS)

Davies, Christopher J.; Pommier, Anne

2018-01-01

The decline of Mars' global magnetic field some 3.8-4.1 billion years ago is thought to reflect the demise of the dynamo that operated in its liquid core. The dynamo was probably powered by planetary cooling and so its termination is intimately tied to the thermochemical evolution and present-day physical state of the Martian core. Bottom-up growth of a solid inner core, the crystallization regime for Earth's core, has been found to produce a long-lived dynamo leading to the suggestion that the Martian core remains entirely liquid to this day. Motivated by the experimentally-determined increase in the Fe-S liquidus temperature with decreasing pressure at Martian core conditions, we investigate whether Mars' core could crystallize from the top down. We focus on the "iron snow" regime, where newly-formed solid consists of pure Fe and is therefore heavier than the liquid. We derive global energy and entropy equations that describe the long-timescale thermal and magnetic history of the core from a general theory for two-phase, two-component liquid mixtures, assuming that the snow zone is in phase equilibrium and that all solid falls out of the layer and remelts at each timestep. Formation of snow zones occurs for a wide range of interior and thermal properties and depends critically on the initial sulfur concentration, ξ0. Release of gravitational energy and latent heat during growth of the snow zone do not generate sufficient entropy to restart the dynamo unless the snow zone occupies at least 400 km of the core. Snow zones can be 1.5-2 Gyrs old, though thermal stratification of the uppermost core, not included in our model, likely delays onset. Models that match the available magnetic and geodetic constraints have ξ0 ≈ 10% and snow zones that occupy approximately the top 100 km of the present-day Martian core.

SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOLID OXIDE FUEL CELL

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

Steven Shaffer; Sean Kelly; Subhasish Mukerjee

2004-05-07

The objective of this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with the option of piped-in water (Demonstration System A). Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine.more » This technical progress report covers work performed by Delphi from July 1, 2003 to December 31, 2003, under Department of Energy Cooperative Agreement DE-FC-02NT41246. This report highlights technical results of the work performed under the following tasks: Task 1 System Design and Integration; Task 2 Solid Oxide Fuel Cell Stack Developments; Task 3 Reformer Developments; Task 4 Development of Balance of Plant (BOP) Components; Task 5 Manufacturing Development (Privately Funded); Task 6 System Fabrication; Task 7 System Testing; Task 8 Program Management; Task 9 Stack Testing with Coal-Based Reformate; and Task 10 Technology Transfer from SECA CORE Technology Program. In this reporting period, unless otherwise noted Task 6--System Fabrication and Task 7--System Testing will be reported within Task 1 System Design and Integration. Task 8--Program Management, Task 9--Stack Testing with Coal Based Reformate, and Task 10--Technology Transfer from SECA CORE Technology Program will be reported on in the Executive Summary section of this report.« less

Experimental evidence of body centered cubic iron in Earth's core

NASA Astrophysics Data System (ADS)

Hrubiak, R.; Meng, Y.; Shen, G.

2017-12-01

The Earth's core is mainly composed of iron. While seismic evidence has shown a liquid outer core and a solid inner core, the crystalline nature of the solid iron at the core condition remains debated, largely due to the difficulties in experimental determination of exact polymorphs at corresponding pressure-temperature conditions. We have examined crystal structures of iron up to 220 GPa and 6000 K with x-ray diffraction using a double-sided laser heating system at HPCAT, Advanced Photon Source. The iron sample is confined in a small chamber surrounded by single crystal MgO. The laser power can be modulated together with temperature measurements. The modulated heating of iron in an MgO single crystal matrix allows for microstructure analysis during heating and after the sample is quenched. We present experimental evidence of a body-centered-cubic (BCC) iron from about 100 GPa and 3000 K to at least 220 GPa and 4000 K. The observed BCC phase may be consistent with a theoretically predicted BCC phase that is dynamically stable in similar pressure-temperature conditions [1]. We will discuss the stability region of the BCC phase and the melting curve of iron and their implications in the nature of the Earth's inner core. References: A. B. Belonoshko et al., Nat. Geosci., 1-6 (2017).

Comparative study on neutron data in integral experiments of MYRRHA mockup critical cores in the VENUS-F reactor

NASA Astrophysics Data System (ADS)

Krása, Antonín; Kochetkov, Anatoly; Baeten, Peter; Vittiglio, Guido; Wagemans, Jan; Bécares, Vicente

2017-09-01

VENUS-F is a fast, zero-power reactor with 30% wt. metallic uranium fuel and solid lead as coolant simulator. It serves as a mockup of the MYRRHA reactor core. This paper describes integral experiments performed in two critical VENUS-F core configurations (with and without graphite reflector). Discrepancies between experiments and Monte Carlo calculations (MCNP5) of keff, fission rate spatial distribution and reactivity effects (lead void and fuel Doppler) depending on a nuclear data library used (JENDL-4.0, ENDF-B-VII.1, JEFF-3.1.2, 3.2, 3.3T2) are presented.

The Power of Social Skills in Character Development: Helping Diverse Learners Succeed.

ERIC Educational Resources Information Center

Scully, Jennifer L.

Students must demonstrate not only academic ability but also social competence as they develop to become involved members of society. This guide for teachers, parents, and other professionals addresses the necessity for teaching students social competence as they also learn their core academic material. The program starts with solid lessons in…

A zebrafish embryo behaves both as a "cortical shell-liquid core" structure and a homogeneous solid when experiencing mechanical forces.

PubMed

Liu, Fei; Wu, Dan; Chen, Ken

2014-12-01

Mechanical properties are vital for living cells, and various models have been developed to study the mechanical behavior of cells. However, there is debate regarding whether a cell behaves more similarly to a "cortical shell-liquid core" structure (membrane-like) or a homogeneous solid (cytoskeleton-like) when experiencing stress by mechanical forces. Unlike most experimental methods, which concern the small-strain deformation of a cell, we focused on the mechanical behavior of a cell undergoing small to large strain by conducting microinjection experiments on zebrafish embryo cells. The power law with order of 1.5 between the injection force and the injection distance indicates that the cell behaves as a homogenous solid at small-strain deformation. The linear relation between the rupture force and the microinjector radius suggests that the embryo behaves as membrane-like when subjected to large-strain deformation. We also discuss the possible reasons causing the debate by analyzing the mechanical properties of F-actin filaments.

Ultra-short pulse delivery at high average power with low-loss hollow core fibers coupled to TRUMPF's TruMicro laser platforms for industrial applications

NASA Astrophysics Data System (ADS)

Baumbach, S.; Pricking, S.; Overbuschmann, J.; Nutsch, S.; Kleinbauer, J.; Gebs, R.; Tan, C.; Scelle, R.; Kahmann, M.; Budnicki, A.; Sutter, D. H.; Killi, A.

2017-02-01

Multi-megawatt ultrafast laser systems at micrometer wavelength are commonly used for material processing applications, including ablation, cutting and drilling of various materials or cleaving of display glass with excellent quality. There is a need for flexible and efficient beam guidance, avoiding free space propagation of light between the laser head and the processing unit. Solid core step index fibers are only feasible for delivering laser pulses with peak powers in the kW-regime due to the optical damage threshold in bulk silica. In contrast, hollow core fibers are capable of guiding ultra-short laser pulses with orders of magnitude higher peak powers. This is possible since a micro-structured cladding confines the light within the hollow core and therefore minimizes the spatial overlap between silica and the electro-magnetic field. We report on recent results of single-mode ultra-short pulse delivery over several meters in a lowloss hollow core fiber packaged with industrial connectors. TRUMPF's ultrafast TruMicro laser platforms equipped with advanced temperature control and precisely engineered opto-mechanical components provide excellent position and pointing stability. They are thus perfectly suited for passive coupling of ultra-short laser pulses into hollow core fibers. Neither active beam launching components nor beam trackers are necessary for a reliable beam delivery in a space and cost saving packaging. Long term tests with weeks of stable operation, excellent beam quality and an overall transmission efficiency of above 85 percent even at high average power confirm the reliability for industrial applications.

Electromechanical modeling of a honeycomb core integrated vibration energy converter with increased specific power for energy harvesting applications

NASA Astrophysics Data System (ADS)

Chandrasekharan, Nataraj

Innovation in integrated circuit technology along with improved manufacturing processes has resulted in considerable reduction in power consumption of electromechanical devices. Majority of these devices are currently powered by batteries. However, the issues posed by batteries, including the need for frequent battery recharge/replacement has resulted in a compelling need for alternate energy to achieve self-sufficient device operation or to supplement battery power. Vibration based energy harvesting methods through piezoelectric transduction provides with a promising potential towards replacing or supplementing battery power source. However, current piezoelectric energy harvesters generate low specific power (power-to-weight ratio) when compared to batteries that the harvesters seek to replace or supplement. In this study, the potential of integrating lightweight cellular honeycomb structures with existing piezoelectric device configurations (bimorph) to achieve higher specific power is investigated. It is shown in this study that at low excitation frequency ranges, replacing the solid continuous substrate of a conventional piezoelectric bimorph with honeycomb structures of the same material results in a significant increase in power-to-weight ratio of the piezoelectric harvester. In order to maximize the electrical response of vibration based power harvesters, the natural frequency of these harvesters is designed to match the input driving frequency. The commonly used technique of adding a tip mass is employed to lower the natural frequency (to match driving frequency) of both, solid and honeycomb substrate bimorphs. At higher excitation frequency, the natural frequency of the traditional solid substrate bimorph can only be altered (to match driving frequency) through a change in global geometric design parameters, typically achieved by increasing the thickness of the harvester. As a result, the size of the harvester is increased and can be disadvantageous especially if the application imposes a space/size constraint. Moreover, the bimorph with increased thickness will now require a larger mechanical force to deform the structure which can fall outside the input ambient excitation amplitude range. In contrast, the honeycomb core bimorph offers an advantage in terms of preserving the global geometric dimensions. The natural frequency of the honeycomb core bimorph can be altered by manipulating honeycomb cell design parameters, such as cell angle, cell wall thickness, vertical cell height and inclined cell length. This results in a change in the mass and stiffness properties of the substrate and hence the bimorph, thereby altering the natural frequency of the harvester. Design flexibility of honeycomb core bimorphs is demonstrated by varying honeycomb cell parameters to alter mass and stiffness properties for power harvesting. The influence of honeycomb cell parameters on power generation is examined to evaluate optimum design to attain highest specific power. In addition, the more compliant nature of a honeycomb core bimorph decreases susceptibility towards fatigue and can increase the operating lifetime of the harvester. The second component of this dissertation analyses an uncoupled equivalent circuit model for piezoelectric energy harvesting. Open circuit voltage developed on the piezoelectric materials can be easily computed either through analytical or finite element models. The efficacy of a method to determine power developed across a resistive load, by representing the coupled piezoelectric electromechanical problem with an external load as an open circuit voltage driven equivalent circuit, is evaluated. The lack of backward feedback at finite resistive loads resulting from such an equivalent representation is examined by comparing the equivalent circuit model to the governing equations of a fully coupled circuit model for the electromechanical problem. It is found that the backward feedback is insignificant for weakly coupled systems typically seen in micro electromechanical systems and other energy harvesting device configurations with low coupling. For moderate to high coupling systems, a correction factor based on a calibrated resistance is presented which can be used to evaluate power generation at a specific resistive load.

Has Earth's Plate Tectonics Led to Rapid Core Cooling?

NASA Astrophysics Data System (ADS)

de Montserrat Navarro, A.; Morgan, J. P.; Vannucchi, P.; Connolly, J. A.

2016-12-01

Earth's mantle and core are convecting planetary heat engines. The mantle convects to lose heat from secular cooling, internal radioactivity, and core heatflow across its base. Its convection generates plate tectonics, volcanism, and the loss of 35 TW of mantle heat through Earth's surface. The core convects to lose heat from secular cooling, small amounts of internal radioactivity, and the freezing-induced growth of a compositionally denser inner core. Until recently, the geodynamo was thought to be powered by 4 TW of heatloss across the core-mantle boundary. More recent determinations of the outer core's thermal conductivity (Pozzo et al., 2012; Gomi et al., 2013) would imply that >15 TW of power should conduct down its adiabat. Secular core cooling has been previously thought to be too slow for this, based on estimates for the Clapeyron Slope for high-pressure freezing of an idealized pure-iron core (cf. Nimmo, 2007). The 500-1000 kg m-3 seismically-inferred jump in density between the liquid outer core and solid inner core allows a direct estimate of the Clapeyron Slope for the outer core's actual composition which contains 0.08±0.02 lighter elements (S,Si,O,Al, H,…) mixed into a Fe-Ni alloy. A PREM-like 600 kg m-3 density jump yields a Clapeyron Slope for which there has been 774K of core cooling during the freezing and growth of the inner core, cooling that has been releasing an average of 21 TW of power during the past 3 Ga. If so, core cooling could easily have powered Earth's long-lived geodynamo. Another implication is that the present-day mantle is strongly `bottom-heated', and diapiric mantle plumes should dominate deep mantle upwelling. This mode of core and mantle convection is consistent with slow, 37.5K/Ga secular cooling of Earth's mantle linked to more rapid secular cooling of the core (cf. Morgan, Rüpke, and White, 2016). Efficient plate subduction, hence plate tectonics, is a key ingredient for such rapid secular core cooling.We also show how a more complete thermodynamic version of Birch's accretional energy calculation predicts that accretion with FeNi-sinking-linked differentiation between an Earth-like mantle and core would naturally generate a core that, post-accretion, was both hotter than overlying mantle and 1000K hotter than today.

Nuclear-Rocket Propulsion

NASA Technical Reports Server (NTRS)

Rom, Frank E.

1968-01-01

The three basic types of nuclear power-plants (solid, liquid, and gas core) are compared on the bases of performance potential and the status of current technology. The solid-core systems are expected to have impulses in the range of 850 seconds, any thrust level (as long as it is greater than 10,000 pounds (44,480 newtons)), and thrust-to-engine-weight ratios of 2 to 20 pounds per pound (19.7 to 197 newtons per kilogram). There is negligible or no fuel loss from the solid-core system. The solid-core system, of course, has had the most work done on it. Large-scale tests have been performed on a breadboard engine that has produced specific impulses greater than 700 seconds at thrust levels of about 50,000 pounds (222,000 newtons). The liquid-core reactor would be interesting in the specific impulse range of 1200 to 1500 seconds. Again, any thrust level can be obtained depending on how big or small the reactor is made. The thrust-to-engine weight ratio for these systems would be in the range of 1 to 10. The discouraging feature of the liquid-core system is the high fuel-loss ratio anticipated. Values of 0.01 to 0.1 pound (0.00454 to 0.0454 kilograms) or uranium loss per pound (0.454 kilograms) of hydrogen are expected, if impulses in the range of 1200 to 1500 seconds are desired. The gas-core reactor shows specific impulses in the range of 1500 to 2500 seconds. The thrust levels should be at least as high as the weight so that the thrust-to-weight ratio does not go below 1. Because the engine weight is not expected to be under 100,000 pounds (444,800 newtons), thrust levels higher than 100,000 pounds (448,000 newtons) are of interest. The thrust-to-engine weights, in that case, would run from 1 to 20 pounds per pound (9.8 to 19.7 kilograms). Gas-core reactors tend to be very large, and can have high thrust-to-weight ratios. As in the case of the liquid-core system, the fuel loss that will be attendant with gas cores as envisioned today will be rather high. The loss rates will be 0.01 to 0.1 pound of uranium (0.00454 to 0.0454 kilograms) for each pound (0.454 kilograms) of hydrogen.

Solid core dipoles and switching power supplies: Lower cost light sources?

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

Benesch, Jay; Philip, Sarin

As a result of improvements in power semiconductors, moderate frequency switching supplies can now provide the hundreds of amps typically required by accelerators with zero-to-peak noise in the kHz region ~ 0.06% in current or voltage mode. Modeling was undertaken using a finite electromagnetic program to determine if eddy currents induced in the solid steel of CEBAF magnets and small supplemental additions would bring the error fields down to the 5ppm level needed for beam quality. The expected maximum field of the magnet under consideration is 0.85 T and the DC current required to produce that field is used inmore » the calculations. An additional 0.1% current ripple is added to the DC current at discrete frequencies 360 Hz, 720 Hz or 7200 Hz. Over the region of the pole within 0.5% of the central integrated BdL the resulting AC field changes can be reduced to less than 1% of the 0.1% input ripple for all frequencies, and a sixth of that at 7200 Hz. Doubling the current, providing 1.5 T central field, yielded the same fractional reduction in ripple at the beam for the cases checked. A small dipole was measured at 60, 120, 360 and 720 Hz in two conditions and the results compared to the larger model for the latter two frequencies with surprisingly good agreement. Thus, for light sources with aluminum vacuum vessels and full energy linac injection, the combination of solid core dipoles and switching power supplies may result in significant cost savings.« less

Energy Harvesting from the Stray Electromagnetic Field around the Electrical Power Cable for Smart Grid Applications

PubMed Central

2016-01-01

For wireless sensor node (WSN) applications, this paper presents the harvesting of energy from the stray electromagnetic field around an electrical power line. Inductive and capacitive types of electrodynamic energy harvesters are developed and reported. For the produced energy harvesters, solid core and split-core designs are adopted. The inductive energy harvester comprises a copper wound coil which is produced on a mild steel core. However, the capacitive prototypes comprise parallel, annular discs separated by Teflon spacers. Moreover, for the inductive energy harvesters' wound coil and core, the parametric analysis is also performed. A Teflon housing is incorporated to protect the energy harvester prototypes from the harsh environmental conditions. Among the inductive energy harvesters, prototype-5 has performed better than the other harvesters and produces a maximum rms voltage of 908 mV at the current level of 155 A in the power line. However, at the same current flow, the capacitive energy harvesters produce a maximum rms voltage of 180 mV. The alternating output of the prototype-5 is rectified, and a super capacitor (1 F, 5.5 V) and rechargeable battery (Nickel-Cadmium, 3.8 V) are charged with it. Moreover, with the utilization of a prototype-5, a self-powered wireless temperature sensing and monitoring system for an electrical transformer is also developed and successfully implemented. PMID:27579343

Energy Harvesting from the Stray Electromagnetic Field around the Electrical Power Cable for Smart Grid Applications.

PubMed

Khan, Farid Ullah

For wireless sensor node (WSN) applications, this paper presents the harvesting of energy from the stray electromagnetic field around an electrical power line. Inductive and capacitive types of electrodynamic energy harvesters are developed and reported. For the produced energy harvesters, solid core and split-core designs are adopted. The inductive energy harvester comprises a copper wound coil which is produced on a mild steel core. However, the capacitive prototypes comprise parallel, annular discs separated by Teflon spacers. Moreover, for the inductive energy harvesters' wound coil and core, the parametric analysis is also performed. A Teflon housing is incorporated to protect the energy harvester prototypes from the harsh environmental conditions. Among the inductive energy harvesters, prototype-5 has performed better than the other harvesters and produces a maximum rms voltage of 908 mV at the current level of 155 A in the power line. However, at the same current flow, the capacitive energy harvesters produce a maximum rms voltage of 180 mV. The alternating output of the prototype-5 is rectified, and a super capacitor (1 F, 5.5 V) and rechargeable battery (Nickel-Cadmium, 3.8 V) are charged with it. Moreover, with the utilization of a prototype-5, a self-powered wireless temperature sensing and monitoring system for an electrical transformer is also developed and successfully implemented.

Gas-core reactor power transient analysis

NASA Technical Reports Server (NTRS)

Kascak, A. F.

1972-01-01

The gas core reactor is a proposed device which features high temperatures. It has applications in high specific impulse space missions, and possibly in low thermal pollution MHD power plants. The nuclear fuel is a ball of uranium plasma radiating thermal photons as opposed to gamma rays. This thermal energy is picked up before it reaches the solid cavity liner by an inflowing seeded propellant stream and convected out through a rocket nozzle. A wall-burnout condition will exist if there is not enough flow of propellant to convect the energy back into the cavity. A reactor must therefore operate with a certain amount of excess propellant flow. Due to the thermal inertia of the flowing propellant, the reactor can undergo power transients in excess of the steady-state wall burnout power for short periods of time. The objective of this study was to determine how long the wall burnout power could be exceeded without burning out the cavity liner. The model used in the heat-transfer calculation was one-dimensional, and thermal radiation was assumed to be a diffusion process.

Tethered tertiary amines as solid-state n-type dopants for solution-processable organic semiconductors

DOE PAGES

Russ, Boris; Robb, Maxwell J.; Popere, Bhooshan C.; ...

2015-12-09

A scarcity of stable n-type doping strategies compatible with facile processing has been a major impediment to the advancement of organic electronic devices. Localizing dopants near the cores of conductive molecules can lead to improved efficacy of doping. We and others recently showed the effectiveness of tethering dopants covalently to an electron-deficient aromatic molecule using trimethylammonium functionalization with hydroxide counterions linked to a perylene diimide core by alkyl spacers. In this work, we demonstrate that, contrary to previous hypotheses, the main driver responsible for the highly effective doping observed in thin films is the formation of tethered tertiary amine moietiesmore » during thin film processing. Furthermore, we demonstrate that tethered tertiary amine groups are powerful and general n-doping motifs for the successful generation of free electron carriers in the solid-state, not only when coupled to the perylene diimide molecular core, but also when linked with other small molecule systems including naphthalene diimide, diketopyrrolopyrrole, and fullerene derivatives. Our findings help expand a promising molecular design strategy for future enhancements of n-type organic electronic materials.« less

Tethered tertiary amines as solid-state n-type dopants for solution-processable organic semiconductors

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

Russ, Boris; Robb, Maxwell J.; Popere, Bhooshan C.

A scarcity of stable n-type doping strategies compatible with facile processing has been a major impediment to the advancement of organic electronic devices. Localizing dopants near the cores of conductive molecules can lead to improved efficacy of doping. We and others recently showed the effectiveness of tethering dopants covalently to an electron-deficient aromatic molecule using trimethylammonium functionalization with hydroxide counterions linked to a perylene diimide core by alkyl spacers. In this work, we demonstrate that, contrary to previous hypotheses, the main driver responsible for the highly effective doping observed in thin films is the formation of tethered tertiary amine moietiesmore » during thin film processing. Furthermore, we demonstrate that tethered tertiary amine groups are powerful and general n-doping motifs for the successful generation of free electron carriers in the solid-state, not only when coupled to the perylene diimide molecular core, but also when linked with other small molecule systems including naphthalene diimide, diketopyrrolopyrrole, and fullerene derivatives. Our findings help expand a promising molecular design strategy for future enhancements of n-type organic electronic materials.« less

Solid core dipoles and switching power supplies: lower cost light sources?

NASA Astrophysics Data System (ADS)

Benesch, J.; Philip, S.

2015-05-01

As a result of improvements in power semiconductors, moderate frequency switching supplies can now provide the hundreds of amps typically required by accelerators with zero-to-peak noise in the kHz region ~ 0.06% in current or voltage mode. Modeling was undertaken using a finite electromagnetic program to determine if eddy currents induced in the solid steel of CEBAF magnets and small supplemental additions would bring the error fields down to the 5ppm level needed for beam quality. The expected maximum field of the magnet under consideration is 0.85 T and the DC current required to produce that field is used in the calculations. An additional 0.1% current ripple is added to the DC current at discrete frequencies 360 Hz, 720 Hz or 7200 Hz. Over the region of the pole within 0.5% of the central integrated BdL the resulting AC field changes can be reduced to less than 1% of the 0.1% input ripple for all frequencies, and a sixth of that at 7200 Hz. Doubling the current, providing 1.5 T central field, yielded the same fractional reduction in ripple at the beam for the cases checked. A small dipole was measured at 60, 120, 360 and 720 Hz in two conditions and the results compared to the larger model for the latter two frequencies with surprisingly good agreement. For light sources with aluminum vacuum vessels and full energy linac injection, the combination of solid core dipoles and switching power supplies may result in significant cost savings. The work may also be used to guide retrofit of existing machines to reduce the level of ripple in the particle beam path.

Comparative Analysis of Hexagonal Solid Silica and Nitro-benzene Filled Hollow Core Photonic Crystal Fiber

NASA Astrophysics Data System (ADS)

Shahiruddin; Singh, Dharmendra K.; Hassan, M. A.

2018-02-01

A comparative study of five ring solid core and nitrobenzene filled hollow core liquid filled photonic crystal fiber (PCF) are presented. Considering the same structure, one is used as solid silica and another one is filled with nitrobenzene in the core. Here the paper elaborates the confinement loss, dispersion properties and birefringence of an index-guiding PCF with asymmetric cladding designed and analyzed by the finite-element method. The proposed structure shows the low confinement loss in case of solid silica, negative dispersion in nitrobenzene filled hollow core PCF and high birefringence in both the cases. The calculated values shows flat zero confinement loss in 0.7 µm to 1.54 µm range, flat zero dispersion is achieved in solid core and -2000 ps/km-nm in nitrobenzene filled hollow core PCF and high birefringence in the range of 10-3 in nitrobenzene filled hollow core PCF. Results show the relative analysis at different air fill fraction.

Compact high voltage, high peak power, high frequency transformer for converter type modulator applications.

PubMed

Reghu, T; Mandloi, V; Shrivastava, Purushottam

2016-04-01

The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed.

From Mixed-Metal MOFs to Carbon-Coated Core-Shell Metal Alloy@Metal Oxide Solid Solutions: Transformation of Co/Ni-MOF-74 to CoxNi1-x@CoyNi1-yO@C for the Oxygen Evolution Reaction.

PubMed

Sun, Dengrong; Ye, Lin; Sun, Fangxiang; García, Hermenegildo; Li, Zhaohui

2017-05-01

Calcination of the mixed-metal species Co/Ni-MOF-74 leads to the formation of carbon-coated Co x Ni 1-x @Co y Ni 1-y O with a metal core diameter of ∼3.2 nm and a metal oxide shell thickness of ∼2.4 nm embedded uniformly in the ligand-derived carbon matrix. The close proximity of Co and Ni in the mixed-metal Co/Ni-MOF-74 promotes the metal alloying and the formation of a solid solution of metal oxide during the calcination process. The presence of the tightly coated carbon shell prohibits particle agglomeration and stabilizes the Co x Ni 1-x @Co y Ni 1-y O nanoparticles in small size. The Co x Ni 1-x @Co y Ni 1-y O@C derived from Co/Ni-MOF-74 nanocomposites show superior performance for the oxygen evolution reaction (OER). The use of mixed-metal MOFs as precursors represents a powerful strategy for the fabrication of metal alloy@metal oxide solid solution nanoparticles in small size. This method also holds great promise in the development of multifunctional carbon-coated complex core-shell metal/metal oxides owing to the diversified MOF structures and their flexible chemistry.

Preliminary results of Linear Induction Accelerator LIA-200

NASA Astrophysics Data System (ADS)

Sharma, Archana; Senthil, K.; Praveen Kumar, D. D.; Mitra, S.; Sharma, V.; Patel, A.; Sharma, D. K.; Rehim, R.; Kolge, T. S.; Saroj, P. C.; Acharya, S.; Amitava, Roy; Rakhee, M.; Nagesh, K. V.; Chakravarthy, D. P.

2010-05-01

Repetitive Pulsed Power Technology is being developed keeping in mind the potential applications of this technology in material modifications, disinfections of water, timber, and food pasteurization etc. BARC has indigenously developed a Linear Induction Accelerator (LIA-200) rated for 200 kV, 4 kA, 100 ns, 10 Hz. The satisfactory performance of all the sub-systems including solid state power modulator, amorphous core based pulsed transformers, magnetic switches, water capacitors, water pulse- forming line, induction adder and field-emission diode have been demonstrated. This paper presents some design details and operational results of this pulsed power system. It also highlights the need for further research and development to build reliable and economic high-average power systems for industrial applications.

WWER-1000 core and reflector parameters investigation in the LR-0 reactor

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

Zaritsky, S. M.; Alekseev, N. I.; Bolshagin, S. N.

2006-07-01

Measurements and calculations carried out in the core and reflector of WWER-1000 mock-up are discussed: - the determination of the pin-to-pin power distribution in the core by means of gamma-scanning of fuel pins and pin-to-pin calculations with Monte Carlo code MCU-REA and diffusion codes MOBY-DICK (with WIMS-D4 cell constants preparation) and RADAR - the fast neutron spectra measurements by proton recoil method inside the experimental channel in the core and inside the channel in the baffle, and corresponding calculations in P{sub 3}S{sub 8} approximation of discrete ordinates method with code DORT and BUGLE-96 library - the neutron spectra evaluations (adjustment)more » in the same channels in energy region 0.5 eV-18 MeV based on the activation and solid state track detectors measurements. (authors)« less

Lunar Fluid Core and Solid-Body Tides

NASA Technical Reports Server (NTRS)

Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.

2005-01-01

Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) [2-5] and fluid core moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core [1] plus Love number [1-5]. Detection of CMB flattening has been improving [3,5] and now seems significant. This strengthens the case for a fluid lunar core.

Design and Testing of a Breadboard Electrical Power Control Unit for the Fluid Combustion Facility Experiment

NASA Technical Reports Server (NTRS)

Kimnach, Greg L.; Lebron, Ramon C.

1999-01-01

The Fluid Combustion Facility (FCF) Project and the Power Technology Division at the NASA Glenn Research Center (GRC) at Lewis Field in Cleveland, OH along with the Sundstrand Corporation in Rockford, IL are jointly developing an Electrical Power Converter Unit (EPCU) for the Fluid Combustion Facility to be flown on the International Space Station (ISS). The FCF facility experiment contains three racks: A core rack, a combustion rack, and a fluids rack. The EPCU will be used as the power interface to the ISS 120V(sub dc) power distribution system by each FCF experiment rack which requires 28V(sub dc). The EPCU is a modular design which contains three 120V(sub dc)-to-28V(sub dc) full-bridge, power converters rated at 1 kW(sub e) each bus transferring input relays and solid-state, current-limiting input switches, 48 current-limiting, solid-state, output switches; and control and telemetry hardware. The EPCU has all controls required to autonomously share load demand between the power feeds and--if absolutely necessary--shed loads. The EPCU, which maximizes the usage of allocated ISS power and minimizes loss of power to loads, can be paralleled with other EPCUs. This paper overviews the electrical design and operating characteristics of the EPCU and presents test data from the breadboard design.

Lunar Science from Lunar Laser Ranging

NASA Technical Reports Server (NTRS)

Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.

2013-01-01

Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, tidal Love number k2, and moment of inertia differences. There is weaker sensitivity to flattening of the core/mantle boundary (CMB) and fluid core moment of inertia. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to variations in lunar rotation, orientation and tidal displacements. Past solutions using the LLR data have given results for Love numbers plus dissipation due to solid-body tides and fluid core. Detection of the fluid core polar minus equatorial moment of inertia difference due to CMB flattening is weakly significant. This strengthens the case for a fluid lunar core. Future approaches are considered to detect a solid inner core.

Realization and optimization of a 1 ns pulsewidth multi-stage 250 kW peak power monolithic Yb doped fiber amplifier at 1064 nm

NASA Astrophysics Data System (ADS)

Morasse, Bertrand; Plourde, Estéban

2017-02-01

We present a simple way to achieve and optimize hundreds of kW peak power pulsed output using a monolithic amplifier chain based on solid core double cladding fiber tightly packaged. A fiber pigtailed current driven diode is used to produce nanosecond pulses at 1064 nm. We present how to optimize the use of Fabry-Perot versus DFB type diode along with the proper wavelength locking using a fiber Bragg grating. The optimization of the two pre-amplifiers with respect to the pump wavelength and Yb inversions is presented. We explain how to manage ASE using core and cladding pumping and by using single pass and double pass amplifier. ASE rejection within the Yb fiber itself and with the use of bandpass filter is discussed. Maximizing the amplifier conversion efficiency with regards to the fiber parameters, glass matrix and signal wavelength is described in details. We present how to achieve high peak power at the power amplifier stage using large core/cladding diameter ratio highly doped Yb fibers pumped at 975 nm. The effect of pump bleaching on the effective Yb fiber length is analyzed carefully. We demonstrate that counter-pumping brings little advantage in very short length amplifier. Dealing with the self-pulsation limit of stimulated Brillouin scattering is presented with the adjustment of the seed pulsewidth and linewidth. Future prospects for doubling the output peak power are discussed.

Solar Pumped Solid State Lasers for Space Solar Power: Experimental Path

NASA Technical Reports Server (NTRS)

Fork, Richard L.; Carrington, Connie K.; Walker, Wesley W.; Cole, Spencer T.; Green, Jason J. A.; Laycock, Rustin L.

2003-01-01

We outline an experimentally based strategy designed to lead to solar pumped solid state laser oscillators useful for space solar power. Our method involves solar pumping a novel solid state gain element specifically designed to provide efficient conversion of sunlight in space to coherent laser light. Kilowatt and higher average power is sought from each gain element. Multiple such modular gain elements can be used to accumulate total average power of interest for power beaming in space, e.g., 100 kilowatts and more. Where desirable the high average power can also be produced as a train of pulses having high peak power (e.g., greater than 10(exp 10 watts). The modular nature of the basic gain element supports an experimental strategy in which the core technology can be validated by experiments on a single gain element. We propose to do this experimental validation both in terrestrial locations and also on a smaller scale in space. We describe a terrestrial experiment that includes diagnostics and the option of locating the laser beam path in vacuum environment. We describe a space based experiment designed to be compatible with the Japanese Experimental Module (JEM) on the International Space Station (ISS). We anticipate the gain elements will be based on low temperature (approx. 100 degrees Kelvin) operation of high thermal conductivity (k approx. 100 W/cm-K) diamond and sapphire (k approx. 4 W/cm-K). The basic gain element will be formed by sequences of thin alternating layers of diamond and Ti:sapphire with special attention given to the material interfaces. We anticipate this strategy will lead to a particularly simple, robust, and easily maintained low mass modelocked multi-element laser oscillator useful for space solar power.

Optimizing the noise characteristics of high-power fiber laser systems

NASA Astrophysics Data System (ADS)

Jauregui, Cesar; Müller, Michael; Kienel, Marco; Emaury, Florian; Saraceno, Clara J.; Limpert, Jens; Keller, Ursula; Tünnermann, Andreas

2017-02-01

The noise characteristics of high-power fiber lasers, unlike those of other solid-state lasers such as thin-disks, have not been systematically studied up to now. However, novel applications for high-power fiber laser systems, such as attosecond pulse generation, put stringent limits to the maximum noise level of these sources. Therefore, in order to address these applications, a detailed knowledge and understanding of the characteristics of noise and its behavior in a fiber laser system is required. In this work we have carried out a systematic study of the propagation of the relative intensity noise (RIN) along the amplification chain of a state-of-the-art high-power fiber laser system. The most striking feature of these measurements is that the RIN level is progressively attenuated after each amplification stage. In order to understand this unexpected behavior, we have simulated the transfer function of the RIN in a fiber amplification stage ( 80μm core) as a function of the seed power and the frequency. Our simulation model shows that this damping of the amplitude noise is related to saturation. Additionally, we show, for the first time to the best of our knowledge, that the fiber design (e.g. core size, glass composition, doping geometry) can be modified to optimize the noise characteristics of high-power fiber laser systems.

Development of an Efficient CFD Model for Nuclear Thermal Thrust Chamber Assembly Design

NASA Technical Reports Server (NTRS)

Cheng, Gary; Ito, Yasushi; Ross, Doug; Chen, Yen-Sen; Wang, Ten-See

2007-01-01

The objective of this effort is to develop an efficient and accurate computational methodology to predict both detailed thermo-fluid environments and global characteristics of the internal ballistics for a hypothetical solid-core nuclear thermal thrust chamber assembly (NTTCA). Several numerical and multi-physics thermo-fluid models, such as real fluid, chemically reacting, turbulence, conjugate heat transfer, porosity, and power generation, were incorporated into an unstructured-grid, pressure-based computational fluid dynamics solver as the underlying computational methodology. The numerical simulations of detailed thermo-fluid environment of a single flow element provide a mechanism to estimate the thermal stress and possible occurrence of the mid-section corrosion of the solid core. In addition, the numerical results of the detailed simulation were employed to fine tune the porosity model mimic the pressure drop and thermal load of the coolant flow through a single flow element. The use of the tuned porosity model enables an efficient simulation of the entire NTTCA system, and evaluating its performance during the design cycle.

Constructing, connecting and soldering nanostructures by environmental electron beam deposition

NASA Astrophysics Data System (ADS)

Mølhave, Kristian; Nørgaard Madsen, Dorte; Dohn, Søren; Bøggild, Peter

2004-08-01

Highly conductive nanoscale deposits with solid gold cores can be made by electron beam deposition in an environmental scanning electron microscope (ESEM), suggesting the method to be used for constructing, connecting and soldering nanostructures. This paper presents a feasibility study for such applications. We identify several issues related to contamination and unwanted deposition, relevant for deposition in both vacuum (EBD) and environmental conditions (EEBD). We study relations between scan rate, deposition rate, angle and line width for three-dimensional structures. Furthermore, we measure the conductivity of deposits containing gold cores, and find these structures to be highly conductive, approaching the conductivity of solid gold and capable of carrying high current densities. Finally, we study the use of the technique for soldering nanostructures such as carbon nanotubes. Based on the presented results we are able to estimate limits for the applicability of the method for the various applications, but also demonstrate that it is a versatile and powerful tool for nanotechnology within these limits.

Melting of Fe-Si-O alloys: the Fate of Coexisting Si and O in the Core

NASA Astrophysics Data System (ADS)

Arveson, S. M.; Lee, K. K. M.

2017-12-01

The light element budget of Earth's core plays an integral role in sustaining outer core convection, which powers the geodynamo. Many experiments have been performed on binary iron compounds, but the results do not robustly agree with seismological observations and geochemical constraints. Earth's core is almost certainly made up of multiple light elements, so the future of core composition studies lies in ternary (or higher order) systems in order to examine interactions between light elements. We perform melting experiments on Fe-Si-O alloys in a laser-heated diamond-anvil cell to 80 GPa and 4000 K. Using 2D multi- wavelength imaging radiometry together with textural and chemical analysis of quenched samples, we measure the high-pressure melting curves and determine partitioning of light elements between the melt and the coexisting solid. Quenched samples are analyzed both in map view and in cross section using scanning electron microscopy (SEM) and electron microprobe analysis (EPMA) to examine the 3D melt structure and composition. Partitioning of light elements between molten and solid alloys dictates (1) the density contrast at the ICB, which drives compositional convection in the outer core and (2) the temperature of the CMB, an integral parameter for understanding the deep Earth. Our experiments suggest silicon and oxygen do not simply coexist in the melt and instead show complex solubility based on temperature. Additionally, we do not find evidence of crystallization of SiO2 at low oxygen content as was recently reported.11 Hirose, K., et al., Crystallization of silicon dioxide and compositional evolution of the Earth's core. Nature, 2017. 543(7643): p. 99-102.

Advanced specialty fiber designs for high power fiber lasers

NASA Astrophysics Data System (ADS)

Gu, Guancheng

The output power of fiber lasers has increased rapidly over the last decade. There are two major limiting factors, namely nonlinear effects and transverse mode instability, prohibiting the power scaling capability of fiber lasers. The nonlinear effects, originating from high optical intensity, primarily limit the peak power scaling. The mode instability, on the other hand, arises from quantum-defect driven heating, causing undesired mode coupling once the power exceeds the threshold and degradation of beam quality. The mode instability has now become the bottleneck for average output power scaling of fiber lasers. Mode area scaling is the most effective way to mitigate nonlinear effects. However, the use of large mode area may increase the tendency to support multiple modes in the core, resulting in lower mode instability threshold. Therefore, it is critical to maintain single mode operation in a large mode area fiber. Sufficient higher order mode suppression can lead to effective single-transverse-mode propagation. In this dissertation, we explore the feasibility of using specialty fiber to construct high power fiber lasers with robust single-mode output. The first type of fiber discussed is the resonantly-enhanced leakage channel fiber. Coherent reflection at the fiber outer boundary can lead to additional confinement especially for highly leaky HOM, leading to lower HOM losses than what are predicted by conventional finite element mothod mode solver considering infinite cladding. In this work, we conducted careful measurements of HOM losses in two leakage channel fibers (LCF) with circular and rounded hexagonal boundary shapes respectively. Impact on HOM losses from coiling, fiber boundary shapes and coating indexes were studied in comparison to simulations. This work demonstrates the limit of the simulation method commonly used in the large-mode-area fiber designs and the need for an improved approach. More importantly, this work also demonstrates that a deviation from circular fiber outer shape may be an effective method to mitigate HOM loss reduction from coherent reflection from fiber outer boundary. In an all-solid photonic bandgap fiber, modes are only guided due to anti-resonance of cladding photonic crystal lattice. This provides strongly mode-dependent guidance, leading to very high differential mode losses, which is essential for lasing far from the gain peak and suppression of stimulated Raman scattering. We will show that all-solid photonic bandgap fibers with effective mode area of 920microm2 can be made with excellent higher order mode suppression. We then demonstrate a 50microm-core-diameter Yb-doped all-solid photonic bandgap fiber laser. 75W output power has been generated with a diffraction-limited beam and an efficiency of 70% relative to the launched pump power. We have also experimentally confirmed that a robust single-mode regime exists near the high frequency edge of the bandgap. It is well known that incorporation of additional smaller cores in the cladding can be used to resonantly out-couple higher-order modes from a main core to suppress higher-order-mode propagation in the main core. Using a novel design with multiple coupled smaller cores in the cladding, we further scaled up the mode area and have successfully demonstrated a single-mode photonic bandgap fiber with record effective mode area of 2650microm2. Detailed numeric studies have been conducted for multiple cladding designs. For the optimal designs, the simulated minimum higher-order-mode losses are well over two orders of magnitudes higher than that of fundamental mode when expressed in dBs. We have also experimentally validated one of the designs. M 2<1.08 across the transmission band was demonstrated. Lowering quantum defect heating is another approach to mitigate mode instability. Highly-efficient high-power fiber lasers operating at wavelength below 1020nm are critical for tandem-pumping in >10kW fiber lasers to provide high pump brightness and low thermal loading. Using an ytterbium-doped-phosphosilicate double-clad leakage-channel fiber with 50microm core and 420microm cladding, we have achieved 70% optical-to-optical efficiency at 1018nm. The much larger cladding than those in previous reports demonstrates the much lower required pump brightness, a key for efficient kW operation. The demonstrated 1018nm fiber laser has ASE suppression of 41dB. This is higher than previous reports and further demonstrates the advantages of the fiber used. Limiting factors to efficiency are also systematically studied.

Structure of a mushy layer under hypergravity with implications for Earth's inner core

NASA Astrophysics Data System (ADS)

Huguet, Ludovic; Alboussière, Thierry; Bergman, Michael I.; Deguen, Renaud; Labrosse, Stéphane; Lesœur, Germain

2016-03-01

Crystallization experiments in the dendritic regime have been carried out in hypergravity conditions (from 1 to 1300 g) from an ammonium chloride solution (NH4Cl and H2O). A commercial centrifuge was equipped with a slip ring so that electric power (needed for a Peltier device and a heating element), temperature and ultrasonic signals could be transmitted between the experimental setup and the laboratory. Ultrasound measurements (2-6 MHz) were used to detect the position of the front of the mushy zone and to determine attenuation in the mush. Temperature measurements were used to control a Peltier element extracting heat from the bottom of the setup and to monitor the evolution of crystallization in the mush and in the liquid. A significant increase of solid fraction and attenuation in the mush is observed as gravity is increased. Kinetic undercooling is significant in our experiments and has been included in a macroscopic mush model. The other ingredients of the model are conservation of energy and chemical species, along with heat/species transfer between the mush and the liquid phase: boundary-layer exchanges at the top of the mush and bulk convection within the mush (formation of chimneys). The outputs of the model compare well with our experiments. We have then run the model in a range of parameters suitable for the Earth's inner core. This has shown the role of bulk mush convection for the inner core and the reason why a solid fraction very close to unity should be expected. We have also run melting experiments: after crystallization of a mush, the liquid has been heated from above until the mush started to melt, while the bottom cold temperature was maintained. These melting experiments were motivated by the possible local melting at the inner core boundary that has been invoked to explain the formation of the anomalously slow F-layer at the bottom of the outer core or inner core hemispherical asymmetry. Oddly, the consequences of melting are an increase in solid fraction and a decrease in attenuation. It is hence possible that surface seismic velocity and attenuation of the inner core are strongly affected by melting.

Structure of a mushy layer at the inner core boundary

NASA Astrophysics Data System (ADS)

Deguen, R.; Huguet, L.; Bergman, M. I.; Labrosse, S.; Alboussiere, T.

2015-12-01

We present experimental results on the solidification of ammonium chloride from an aqueous solution, yielding a mushy zone, under hyper-gravity. A commercial centrifuge has been equipped with a slip-ring so that electric power, temperature and ultrasonic signals could be transmitted between the experimental setup and the laboratory. A Peltier element provides cooling at the bottom of the cell. Probes monitor the temperature along the height of the cell. Ultrasound measurements (2 to 6 MHz) is used to detect the position of the front of the mushy zone and to determine attenuation in the mush. A significant increase of solid fraction (or decrease of mushy layer thickness) and attenuation in the mush is observed as gravity is increased. Kinetic undercooling is significant in our experiments and has been included in a macroscopic mush model. The other ingredients of the model are conservation of energy and chemical species, along with heat/species transfer between the mush and the liquid phase: boundary-layer exchanges at the top of the mush and bulk convection within the mush (formation of chimneys). The outputs of the model compare well with our experiments. We have then run the model in a range of parameters suitable for the Earth's inner core, which has shown the role of bulk mush convection for the inner core and the reason why a solid fraction very close to unity should be expected. We have also run melting experiments: after crystallization of a mush, the liquid has been heated from above until the mush started to melt, while the bottom cold temperature was maintained. These melting experiments were motivated by the possible local melting at the inner core boundary that has been invoked to explain the formation of the anomalously slow F-layer at the bottom of the outer core or inner core hemispherical asymmetry. Oddly, the consequences of melting are an increase in solid fraction and a decrease in attenuation. It is hence possible that surface seismic velocity and attenuation of the inner core are strongly affected by melting.

Solid-Core Photonic Bandgap Fibers for Cladding-Pumped Raman Amplification

DTIC Science & Technology

2011-06-03

L. Leick, J. Broeng, and S. Selleri, “Single-mode analysis of Yb- doped double-cladding distributed spectral filtering photonic crystal fibers ,” Opt... fiber amplifiers are analyzed theoretically as possible candidates for power scaling. An example fiber design with a mode field diameter of 46 µm and... doped fiber laser with true single-mode output using W-type structure,” in Conference on Lasers and Electro-Optics, (Optical Society of America, 2006

Liquid-Solid Interaction in Al-Si/Al-Mn-Cu-Mg Brazing Sheets and Its Effects on Mechanical Properties

NASA Astrophysics Data System (ADS)

Jin, H.; Kozdras, M. S.; Amirkhiz, B. Shalchi; Winkler, S. L.

2018-05-01

The liquid-solid interaction during brazing at 592 °C to 605 °C and its effects on mechanical properties were investigated in a series of Al-Si/Al-Mn-Cu-Mg brazing sheets with different Mg contents. Depending on the Mg level in core alloy and the brazing temperature, critical changes of local chemistry and microstructure related to the liquid-solid interaction occur, including solid-state diffusion, uniform clad-core interface migration, and grain boundary penetration (GBP). When the Mg in core alloy is below 1 wt pct, the interaction is limited and the formation of a dense precipitation band due to solid-state diffusion of Si from the clad to the core is dominant. As the Mg exceeds 1 wt pct, very extensive interaction occurs resulting in clad-core interface migration and GBP of Si into the core, both involving local melting and re-solidification of the core alloy. Whenever Si from the clad encounters Mg in the core due to the interaction, Mg2Si precipitates are formed leading to significant improvement of strength. However, the interface migration and GBP drastically reduce the ductility, due to the segregation of coarse secondary phase particles along the newly formed grain boundaries.

Liquid-Solid Interaction in Al-Si/Al-Mn-Cu-Mg Brazing Sheets and Its Effects on Mechanical Properties

NASA Astrophysics Data System (ADS)

Jin, H.; Kozdras, M. S.; Amirkhiz, B. Shalchi; Winkler, S. L.

2018-07-01

The liquid-solid interaction during brazing at 592 °C to 605 °C and its effects on mechanical properties were investigated in a series of Al-Si/Al-Mn-Cu-Mg brazing sheets with different Mg contents. Depending on the Mg level in core alloy and the brazing temperature, critical changes of local chemistry and microstructure related to the liquid-solid interaction occur, including solid-state diffusion, uniform clad-core interface migration, and grain boundary penetration (GBP). When the Mg in core alloy is below 1 wt pct, the interaction is limited and the formation of a dense precipitation band due to solid-state diffusion of Si from the clad to the core is dominant. As the Mg exceeds 1 wt pct, very extensive interaction occurs resulting in clad-core interface migration and GBP of Si into the core, both involving local melting and re-solidification of the core alloy. Whenever Si from the clad encounters Mg in the core due to the interaction, Mg2Si precipitates are formed leading to significant improvement of strength. However, the interface migration and GBP drastically reduce the ductility, due to the segregation of coarse secondary phase particles along the newly formed grain boundaries.

Advanced Materials and Solids Analysis Research Core (AMSARC)

EPA Science Inventory

The Advanced Materials and Solids Analysis Research Core (AMSARC), centered at the U.S. Environmental Protection Agency's (EPA) Andrew W. Breidenbach Environmental Research Center in Cincinnati, Ohio, is the foundation for the Agency's solids and surfaces analysis capabilities. ...

Recent advancements in transparent ceramics and crystal fibers for high power lasers

NASA Astrophysics Data System (ADS)

Kim, W.; Baker, C.; Villalobos, G.; Florea, C.; Gibson, D.; Shaw, L. B.; Bowman, S.; Bayya, S.; Sadowski, B.; Hunt, M.; Askins, C.; Peele, J.; Aggarwal, I. D.; Sanghera, J. S.

2013-05-01

In this paper, we present our recent progress in the development of rare-earth (Yb3+ or Ho3+) doped Lu2O3 and Y2O3 sesquioxides for high power solid state lasers. We have fabricated high quality transparent ceramics using nano-powders synthesized by a co-precipitation method. This was accomplished by developments in high purity powder synthesis and low temperature scalable sintering technology developed at NRL. The optical, spectral and morphological properties as well as the lasing performance from our highly transparent ceramics are presented. In the second part of the paper, we discuss our recent research effort in developing cladded-single crystal fibers for high power single frequency fiber lasers has the potential to significantly exceed the capabilities of existing silica fiber based lasers. Single crystal fiber cores with diameters as small as 35μm have been drawn using high purity rare earth doped ceramic or single crystal feed rods by the Laser Heated Pedestal Growth (LHPG) process. Our recent results on the development of suitable claddings on the crystal fiber core are discussed.

Square lattice honeycomb reactor for space power and propulsion

NASA Astrophysics Data System (ADS)

Gouw, Reza; Anghaie, Samim

2000-01-01

The most recent nuclear design study at the Innovative Nuclear Space Power and Propulsion Institute (INSPI) is the Moderated Square-Lattice Honeycomb (M-SLHC) reactor design utilizing the solid solution of ternary carbide fuels. The reactor is fueled with solid solution of 93% enriched (U,Zr,Nb)C. The square-lattice honeycomb design provides high strength and is amenable to the processing complexities of these ultrahigh temperature fuels. The optimum core configuration requires a balance between high specific impulse and thrust level performance, and maintaining the temperature and strength limits of the fuel. The M-SLHC design is based on a cylindrical core that has critical radius and length of 37 cm and 50 cm, respectively. This design utilized zirconium hydrate to act as moderator. The fuel sub-assemblies are designed as cylindrical tubes with 12 cm in diameter and 10 cm in length. Five fuel subassemblies are stacked up axially to form one complete fuel assembly. These fuel assemblies are then arranged in the circular arrangement to form two fuel regions. The first fuel region consists of six fuel assemblies, and 18 fuel assemblies for the second fuel region. A 10-cm radial beryllium reflector in addition to 10-cm top axial beryllium reflector is used to reduce neutron leakage from the system. To perform nuclear design analysis of the M-SLHC design, a series of neutron transport and diffusion codes are used. To optimize the system design, five axial regions are specified. In each axial region, temperature and fuel density are varied. The axial and radial power distributions for the system are calculated, as well as the axial and radial flux distributions. Temperature coefficients of the system are also calculated. A water submersion accident scenario is also analyzed for these systems. Results of the nuclear design analysis indicate that a compact core can be designed based on ternary uranium carbide square-lattice honeycomb fuel, which provides a relatively high thrust to weight ratio. .

Single mode low-NA step index Yb-doped fiber design for output powers beyond 4kW (Conference Presentation)

NASA Astrophysics Data System (ADS)

Beier, Franz; Proske, Fritz; Hupel, Christian; Kuhn, Stefan; Hein, Sigrun; Sattler, Bettina; Nold, Johannes; Haarlammert, Nicoletta; Schreiber, Thomas; Eberhardt, Ramona; Tünnermann, Andreas

2017-03-01

Fiber amplifiers are representing one of the most promising solid state laser concepts, due to the compact setup size, a simple thermal management and furthermore excellent beam quality. In this contribution, we report on the latest results from a low-NA, large mode area single mode fiber with a single mode output power beyond 4 kW without any indication of mode instabilities or nonlinear effects and high slope efficiency. Furthermore, we quantify the influence of the bending diameter of our manufactured low NA fiber on the average core loss by an OFDR measurement and determine the optimal bending diameter in comparison to a second fiber with a slightly changed NA. The fibers used in the experiments were fabricated by MCVD technology combined with the solution doping technique. The investigation indicates the limitation of the step index fiber design and its influence on the use in high power fiber amplifiers. We demonstrate, that even a slightly change in the core NA crucially influences the minimum bending diameter of the fiber and has to be taken into account in applications. The measured output power represents to the best of our knowledge the highest single mode output power of an amplifier fiber ever reported on.

Mechanical and photoelastic analysis of conventional screws and cannulated screws for sagittal split osteotomy fixation: a comparative study.

PubMed

Lima, Cristina Jardelino de; Falci, Saulo Gabriel Moreira; Rodrigues, Danillo Costa; Marchiori, Érica Cristina; Moreira, Roger Willian Fernandes

2015-12-01

The aim of the present study was to use mechanical and photoelastic tests to compare the performance of cannulated screws with solid-core screws in sagittal split osteotomy fixation. Ten polyurethane mandibles, with a prefabricated sagittal split ramus osteotomy, were fixed with an L inverted technique and allocated to each group as follows: cannulated screw group (CSG), fixed with three 2.3-cannulated screws; and solid-core screw group (SCSG), fixed with three 2.3-solid-core screws. Vertical linear loading tests were performed. The differences between mean values were analyzed through T test for independent samples. The photoelastic test was carried out using a polariscope. The results revealed differences between the two groups only at 1 mm of displacement, in which the cannulated-screw revealed more resistance. Photoelastic test showed higher stress concentration close to mandibular branch in the solid-core group. Cannulated screws performed better than solid-core ones in a mechanical test at 1-mm displacement and photoelastic tests.

Elastic guided wave propagation in electrical cables.

PubMed

Mateo, Carlos; Talavera, Juan A; Muñoz, Antonio

2007-07-01

This article analyzes the propagation modes of ultrasound waves inside an electrical cable in order to assess its behavior as an acoustic transmission channel. A theoretical model for propagation of elastic waves in electric power cables is presented. The power cables are represented as viscoelastic-layered cylindrical structures with a copper core and a dielectric cover. The model equations then have been applied and numerically resolved for this and other known structures such as solid and hollow cylinders. The results are compared with available data from other models. Several experimental measures were carried out and were compared with results from the numerical simulations. Experimental and simulated results showed a significant difference between elastic wave attenuation inside standard versus bare, low-voltage power cables.

Packaging of a large capacity magnetic bubble domain spacecraft recorder

NASA Technical Reports Server (NTRS)

Becker, F. J.; Stermer, R. L.

1977-01-01

A Solid State Spacecraft Data Recorder (SSDR), based on bubble domain technology, having a storage capacity of 10 to the 8th power bits, was designed and is being tested. The recorder consists of two memory modules each having 32 cells, each cell containing sixteen 100 kilobit serial bubble memory chips. The memory modules are interconnected to a Drive and Control Unit (DCU) module containing four microprocessors, 500 integrated circuits, a RAM core memory and two PROM's. The two memory modules and DCU are housed in individual machined aluminum frames, are stacked in brick fashion and through bolted to a base plate assembly which also houses the power supply.

Ares V and RS-68B

NASA Technical Reports Server (NTRS)

Creech, Steve; Taylor, Jim; Bellamy, Scott; Kuck, Fritz

2008-01-01

Ares V is the heavy lift vehicle NASA is designing for lunar and other space missions. It has significantly more lift capability than the Saturn V vehicle used for the Apollo missions to the moon. Ares V is powered by two recoverable 5.5 segment solid rocket boosters and six RS-68B engines on the core stage. The upper stage, designated as the Earth Departure Stage, is powered by a single J-2X engine. This paper provides an overview of the Ares V vehicle and the RS-68B engine, an upgrade to the Pratt & Whitney Rocketdyne RS-68 engine developed for the Delta IV vehicle.

Stimulated Raman scattering in AsSe2-As2S5 microstructured optical fiber

NASA Astrophysics Data System (ADS)

Gao, Weiqing; Ni, Chenquan; Xu, Qiang; Li, Xue; Chen, Xiangcai; Chen, Li; Wen, Zhenqiang; Cheng, Tonglei; Xue, Xiaojie; Suzuki, Takenobu; Ohishi, Yasutake

2017-02-01

We demonstrate the effects of stimulated Raman scattering (SRS) in the all-solid-core chalcogenide microstructured optical fibers (MOFs) with AsSe2 core and As2S5 cladding, which are fabricated by the rod-in-tube drawing technique. The core diameters of the MOFs are 6.3 (Fiber I), 3.0 (Fiber II), 2.6 (Fiber III) and 2.2 (Fiber IV) μm, respectively. The chromatic dispersion of the fundamental mode in Fibers I-IV is simulated by the full-vectorial mode solver technique. The first-order Stokes wave is investigated in the fibers with different core diameters pumped by the picosecond pulses at 1958 nm. In Fiber I, no obvious Raman peak is observed with the pump power increasing, because the effective nonlinearity is not high. In Fiber II, a Raman Stokes peak at 2065 nm begins to emerge at the pump power of 110 mW. The conversion efficiency is as weak as -36.6 dB at 150 mW pumping. In Fiber III, the first-order Raman peak at 2060 nm begins to emerge at 40 mW pumping. The conversion efficiency is -15.0 dB, which is 21.6 dB higher than that in Fiber II. In Fiber IV, the Stokes peak at 2070 nm begins to appear at 56 mW pumping. The maximum conversion efficiency of the first-order Stokes wave is obtained in the MOF with the core diameter of 2.6 μm. The evolution of the first-order Stokes wave with pump power and fiber length is investigated. This is the first demonstration of Raman effects in the AsSe2-As2S5 MOF, to the best of our knowledge.

A ``NEW'' Solid-Core Reactor Fuel Form that Maximizes the Performance of Nuclear Thermal and Electric Rockets

NASA Astrophysics Data System (ADS)

Rom, Frank E.; Finnegan, Patrick M.

1994-07-01

The ``NEW'' solid-core fuel form is the old Vapor Transport (VT) fuel pin investigated at NASA about 30 years ago. It is simply a tube sealed at both ends partially filled with UO2. During operation the UO2 forms an annular layer on the inside of the tube by vaporization and condensation. This form is an ideal structure for overall strength and retention of fission products. All of the structural material lies between the fuel (including fission products) and the reactor coolant. The isothermal inside fuel surface temperature that results from the vaporization and condensation of fuel during operation eliminates hotspots, significantly increasing the design fuel pin surface temperature. For NTP, W-UO2 fuel pins yield higher operating temperatures than for other fuel forms, because W has about a ten-fold lower vaporization rate compared to any other known material. The use of perigee propulsion using W-UO2 fuel pins can result in a more than ten-fold reduction in reactor power. Lower reactor power, together with zero fission product release potential, and the simplicity of fabrication of VT fuel pins should greatly simplify and reduce the cost of development of NTP. For NEP, VT fuel pins can increase fast neutron spectrum reactor life with no fission product release. Thermal spectrum NEP reactors using W184 or Mo VT fuel pins, with only small amounts of high neutron absorbing additives, offer benefits because of much lower fissionable fuel requirements. The VT fuel pin has application to commercial power reactors with similar benefits.

Liquid molded hollow cell core composite articles

NASA Technical Reports Server (NTRS)

Bernetich, Karl R. (Inventor)

2005-01-01

A hollow core composite assembly 10 is provided, including a hollow core base 12 having at least one open core surface 14, a bondable solid film 22 applied to the open core surface 14, at least one dry face ply 30 laid up dry and placed on top of the solid film 22, and a liquid resin 32 applied to the at least one dry face ply 30 and then cured.

Partial Melting in the Inner Core

NASA Astrophysics Data System (ADS)

Hernlund, J. W.

2014-12-01

The inner core boundary (ICB) is often considered to be permeable to flow, because solid iron could melt as it upwells across the ICB. Such a mechanism has been proposed to accompany inner core convective processes (including translation from a freezing to melting hemisphere), and has also been invoked to explain the formation of a dense Fe-rich liquid F-layer above the ICB. However, the conceptions of ICB melting invoked thus far are extremely simplistic, and neglect the many lessons learned from melting in other geological contexts. Owing to some degree of solid solution in relatively incompatible light alloys in solid iron, the onset of melting in the inner core will likely occur as a partial melt, with the liquid being enriched in these light alloys relative to the co-existing solid. Such a partial melt is then subject to upward migration/percolation out of the solid matrix owing to the buoyancy of melt relative to solid. Removal of melt and viscous compaction of the pore space results in an iron-enriched dense solid, whose negative buoyancy will oppose whatever buoyancy forces initially gave rise to upwelling. Either the negative buoyancy will balance these other forces and cause upwelling to cease, or else the solid will become so depleted in light alloys that it is unable to undergo further melting. Thus a proper accounting of partial melting results in a very different melting regime in the inner core, and suppression of upwelling across the ICB. Any fluid that is able to escape into the outer core from inner core partial melting will likely be buoyant because in order to be a melt it should be enriched in incompatiable alloys relative to whatever is freezing at the ICB. Therefore inner core melting is unlikely to contribute to the formation of an F-layer, but instead will tend to de-stabilize it. I will present models that illustrate these processes, and propose that the F-layer is a relic of incomplete mixing of the core during Earth's final stages of formation. Such models imply that the inner core may be somewhat older than models in which it crystallizes from a homogeneous outer core, although without any significant benefits for driving the geodynamo.

Simulation study of core heating properties for recent FIREX-I experiments

NASA Astrophysics Data System (ADS)

Johzaki, Tomoyuki; Kai, Yusuke; Endo, Takuma; Nagatomo, Hideo; Sunahara, Atsushi; Sentoku, Yasuhiko; Taguchi, Toshihiro; Fujioka, Shinsuke; Shiraga, Hiroyuki; Azechi, Hiroshi; Firex Project Team

2016-10-01

The demonstration of efficient core heating is the main purpose of FIREX-I project, where Au cone-attached solid ball CD target is used. For the guiding of fast electron beam generated by relativistic laser plasma interactions, the kilo-Tesla-class longitudinal magnetic field is applied by a capacitor-coil target and kJ-class ns-durration high power laser. In addition, to reduce the collisional effect (energy loss and scattering of fast electrons) during propagation in the Au cone tip, we introduced opened-tip cone (tipless cone). To evaluate the core heating properties, we carried out the integrated simulations, which shows the enhancement of core heating efficiency due to the magnetic guiding and opened-tip cone by a factor of three. These simulation results will be shown and be compared with the experimental results. JSPS KAKENHI (26400532, 15H03758, 16H02245, 15K21767), NIFS Collaboration Research program (NIFS12KUGK05, NIFS14KNSS054), and FIREX project.

Nuclear design of a vapor core reactor for space nuclear propulsion

NASA Astrophysics Data System (ADS)

Dugan, Edward T.; Watanabe, Yoichi; Kuras, Stephen A.; Maya, Isaac; Diaz, Nils J.

1993-01-01

Neutronic analysis methodology and results are presented for the nuclear design of a vapor core reactor for space nuclear propulsion. The Nuclear Vapor Thermal Reactor (NVTR) Rocket Engine uses modified NERVA geometry and systems which the solid fuel replaced by uranium tetrafluoride vapor. The NVTR is an intermediate term gas core thermal rocket engine with specific impulse in the range of 1000-1200 seconds; a thrust of 75,000 lbs for a hydrogen flow rate of 30 kg/s; average core exit temperatures of 3100 K to 3400 K; and reactor thermal powers of 1400 to 1800 MW. Initial calculations were performed on epithermal NVTRs using ZrC fuel elements. Studies are now directed at thermal NVTRs that use fuel elements made of C-C composite. The large ZrC-moderated reactors resulted in thrust-to-weight ratios of only 1 to 2; the compact C-C composite systems yield thrust-to-weight ratios of 3 to 5.

Inherently Safe and Long-Life Fission Power System for Lunar Outposts

NASA Astrophysics Data System (ADS)

Schriener, T. M.; El-Genk, Mohamed S.

Power requirements for future lunar outposts, of 10's to 100's kWe, can be fulfilled using nuclear reactor power systems. In addition to the long life and operation reliability, safety is paramount in all phases, including fabrication and assembly, launch, emplacement below grade on the lunar surface, operation, post-operation decay heat removal and long-term storage and eventual retrieval. This paper introduces the Solid Core-Sectored Compact Reactor (SC-SCoRe) and power system with static components and no single point failures. They ensure reliable continuous operation for ~21 years and fulfill the safety requirements. The SC-SCoRe nominally generates 1.0 MWth at liquid NaK-56 coolant inlet and exit temperatures of 850 K and 900 K and the power system provides 38 kWe at high DC voltage using SiGe thermoelectric (TE) conversion assemblies. In case of a loss of coolant or cooling in a reactor core sector, the power system continues to operate; generating ~4 kWe to the outpost for emergency life support needs. The post-operation storage of the reactor below grade on the lunar surface is a safe and practical choice. The total radioactivity in the reactor drops from ~1 million Ci, immediately at shutdown, to below 164 Ci after 300 years of storage. At such time, the reactor is retrieved safely with no contamination or environmental concerns.

A Small Fission Power System for NASA Planetary Science Missions

NASA Technical Reports Server (NTRS)

Mason, Lee; Casani, John; Elliott, John; Fleurial, Jean-Pierre; MacPherson, Duncan; Nesmith, William; Houts, Michael; Bechtel, Ryan; Werner, James; Kapernick, Rick;

Liquid uranium alloy-helium fission reactor

DOEpatents

Minkov, Vladimir

1986-01-01

This invention teaches a nuclear fission reactor having a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200.degree.-1800.degree. C. range, and even higher to 2500.degree. C., limited only by the thermal effectiveness of the structural materials, increasing the efficiency of power generation from the normal 30-35% with 300.degree.-500.degree. C. upper limit temperature to 50-65%. Irradiation of the circulating liquid fuel, as contrasted to only localized irradiation of a solid fuel, provides improved fuel utilization.

Emergency deployable core catcher

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

Rosewell, M.P.

An emergency melt down core catcher apparatus for a nuclear reactor having a retrofitable eutectic solute holding vessel connected to a core containment vessel with particle transferring fluid and particles or granules of solid eutectic solute materials contained therein and transferable by automatically operated valve means to transport and position the solid eutectic solute material in a position below the core to catch and react with any partial or complete melt down of the fuel core.

Shallow Carbon Sequestration Demonstration Project

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

Pendergrass, Gary; Fraley, David; Alter, William

The potential for carbon sequestration at relatively shallow depths was investigated at four power plant sites in Missouri. Exploratory boreholes were cored through the Davis Shale confining layer into the St. Francois aquifer (Lamotte Sandstone and Bonneterre Formation). Precambrian basement contact ranged from 654.4 meters at the John Twitty Energy Center in Southwest Missouri to over 1100 meters near the Sioux Power Plant in St. Charles County. Investigations at the John Twitty Energy Center included 3D seismic reflection surveys, downhole geophysical logging and pressure testing, and laboratory analysis of rock core and water samples. Plans to perform injectivity tests atmore » the John Twitty Energy Center, using food grade CO{sub 2}, had to be abandoned when the isolated aquifer was found to have very low dissolved solids content. Investigations at the Sioux Plant and Thomas Hill Energy Center in Randolph County found suitably saline conditions in the St. Francois. A fourth borehole in Platte County was discontinued before reaching the aquifer. Laboratory analyses of rock core and water samples indicate that the St. Charles and Randolph County sites could have storage potentials worthy of further study. The report suggests additional Missouri areas for further investigation as well.« less

Core-melt source reduction system

DOEpatents

Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

1995-04-25

A core-melt source reduction system for ending the progression of a molten core during a core-melt accident and resulting in a stable solid cool matrix. The system includes alternating layers of a core debris absorbing material and a barrier material. The core debris absorbing material serves to react with and absorb the molten core such that containment overpressurization and/or failure does not occur. The barrier material slows the progression of the molten core debris through the system such that the molten core has sufficient time to react with the core absorbing material. The system includes a provision for cooling the glass/molten core mass after the reaction such that a stable solid cool matrix results. 4 figs.

Core-melt source reduction system

DOEpatents

Forsberg, Charles W.; Beahm, Edward C.; Parker, George W.

1995-01-01

A core-melt source reduction system for ending the progression of a molten core during a core-melt accident and resulting in a stable solid cool matrix. The system includes alternating layers of a core debris absorbing material and a barrier material. The core debris absorbing material serves to react with and absorb the molten core such that containment overpressurization and/or failure does not occur. The barrier material slows the progression of the molten core debris through the system such that the molten core has sufficient time to react with the core absorbing material. The system includes a provision for cooling the glass/molten core mass after the reaction such that a stable solid cool matrix results.

Self-consistent modeling of CFETR baseline scenarios for steady-state operation

NASA Astrophysics Data System (ADS)

Chen, Jiale; Jian, Xiang; Chan, Vincent S.; Li, Zeyu; Deng, Zhao; Li, Guoqiang; Guo, Wenfeng; Shi, Nan; Chen, Xi; CFETR Physics Team

2017-07-01

Integrated modeling for core plasma is performed to increase confidence in the proposed baseline scenario in the 0D analysis for the China Fusion Engineering Test Reactor (CFETR). The steady-state scenarios are obtained through the consistent iterative calculation of equilibrium, transport, auxiliary heating and current drives (H&CD). Three combinations of H&CD schemes (NB + EC, NB + EC + LH, and EC + LH) are used to sustain the scenarios with q min > 2 and fusion power of ˜70-150 MW. The predicted power is within the target range for CFETR Phase I, although the confinement based on physics models is lower than that assumed in 0D analysis. Ideal MHD stability analysis shows that the scenarios are stable against n = 1-10 ideal modes, where n is the toroidal mode number. Optimization of RF current drive for the RF-only scenario is also presented. The simulation workflow for core plasma in this work provides a solid basis for a more extensive research and development effort for the physics design of CFETR.

Vortex-Core Reversal Dynamics: Towards Vortex Random Access Memory

NASA Astrophysics Data System (ADS)

Kim, Sang-Koog

2011-03-01

An energy-efficient, ultrahigh-density, ultrafast, and nonvolatile solid-state universal memory is a long-held dream in the field of information-storage technology. The magnetic random access memory (MRAM) along with a spin-transfer-torque switching mechanism is a strong candidate-means of realizing that dream, given its nonvolatility, infinite endurance, and fast random access. Magnetic vortices in patterned soft magnetic dots promise ground-breaking applications in information-storage devices, owing to the very stable twofold ground states of either their upward or downward core magnetization orientation and plausible core switching by in-plane alternating magnetic fields or spin-polarized currents. However, two technologically most important but very challenging issues --- low-power recording and reliable selection of each memory cell with already existing cross-point architectures --- have not yet been resolved for the basic operations in information storage, that is, writing (recording) and readout. Here, we experimentally demonstrate a magnetic vortex random access memory (VRAM) in the basic cross-point architecture. This unique VRAM offers reliable cell selection and low-power-consumption control of switching of out-of-plane core magnetizations using specially designed rotating magnetic fields generated by two orthogonal and unipolar Gaussian-pulse currents along with optimized pulse width and time delay. Our achievement of a new device based on a new material, that is, a medium composed of patterned vortex-state disks, together with the new physics on ultrafast vortex-core switching dynamics, can stimulate further fruitful research on MRAMs that are based on vortex-state dot arrays.

Armor systems including coated core materials

DOEpatents

Chu, Henry S [Idaho Falls, ID; Lillo, Thomas M [Idaho Falls, ID; McHugh, Kevin M [Idaho Falls, ID

2012-07-31

An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

Armor systems including coated core materials

DOEpatents

Chu, Henry S; Lillo, Thomas M; McHugh, Kevin M

2013-10-08

An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

MEANS FOR CONTROLLING A NUCLEAR REACTOR

DOEpatents

Wilson, V.C.; Overbeck, W.P.; Slotin, L.; Froman, D.K.

1957-12-17

This patent relates to nuclear reactors of the type using a solid neutron absorbing material as a means for controlling the reproduction ratio of the system and thereby the power output. Elongated rods of neutron absorbing material, such as boron steel for example, are adapted to be inserted and removed from the core of tae reactor by electronic motors and suitable drive means. The motors and drive means are controlled by means responsive to the neutron density, such as ionization chambers. The control system is designed to be responsive also to the rate of change in neutron density to automatically maintain the total power output at a substantially constant predetermined value. A safety rod means responsive to neutron density is also provided for keeping the power output below a predetermined maximum value at all times.

Proceedings of the AFOSR Special Conference on Prime-Power for High Energy Space Systems, Norfolk, Virginia, 22-25 February 1982. Volume I.

DTIC Science & Technology

1982-02-25

source both liquid and solid fuel combustion devices have been successfully demonstrated during various development programs . Nuclear reactor heat...U02 fuel in the core . Improving the heat pipe model to correlate more closely with the experimental data is a major concern in the development of...ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT. TASK Research & Development Associates (RDA) AREA &WKNT AE (X Rosslyn, VA 22209 61102F 2301

A hybrid rocket engine design for simple low cost sounding rocket use

NASA Astrophysics Data System (ADS)

Grubelich, Mark; Rowland, John; Reese, Larry

1993-06-01

Preliminary test results on a nitrous oxide/HTPB hybrid rocket engine suitable for powering a small sounding rocket to altitudes of 50-100 K/ft are presented. It is concluded that the advantage of the N2O hybrid engine over conventional solid propellant rocket motors is the ability to obtain long burn times with core burning geometries due to the low regression rate of the fuel. Long burn times make it possible to reduce terminal velocity to minimize air drag losses.

Lunar Core and Tides

NASA Technical Reports Server (NTRS)

Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.

2004-01-01

Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) [2,3,4] and fluid core moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core [1] plus Love number [1-5]. Detection of CMB flattening, which in the past has been marginal but improving [3,4,5], now seems significant. Direct detection of the core moment has not yet been achieved.

Non-invasive, transient determination of the core temperature of a heat-generating solid body

PubMed Central

Anthony, Dean; Sarkar, Daipayan; Jain, Ankur

2016-01-01

While temperature on the surface of a heat-generating solid body can be easily measured using a variety of methods, very few techniques exist for non-invasively measuring the temperature inside the solid body as a function of time. Measurement of internal temperature is very desirable since measurement of just the surface temperature gives no indication of temperature inside the body, and system performance and safety is governed primarily by the highest temperature, encountered usually at the core of the body. This paper presents a technique to non-invasively determine the internal temperature based on the theoretical relationship between the core temperature and surface temperature distribution on the outside of a heat-generating solid body as functions of time. Experiments using infrared thermography of the outside surface of a thermal test cell in a variety of heating and cooling conditions demonstrate good agreement of the predicted core temperature as a function of time with actual core temperature measurement using an embedded thermocouple. This paper demonstrates a capability to thermally probe inside solid bodies in a non-invasive fashion. This directly benefits the accurate performance prediction and control of a variety of engineering systems where the time-varying core temperature plays a key role. PMID:27804981

Non-invasive, transient determination of the core temperature of a heat-generating solid body

NASA Astrophysics Data System (ADS)

Anthony, Dean; Sarkar, Daipayan; Jain, Ankur

2016-11-01

While temperature on the surface of a heat-generating solid body can be easily measured using a variety of methods, very few techniques exist for non-invasively measuring the temperature inside the solid body as a function of time. Measurement of internal temperature is very desirable since measurement of just the surface temperature gives no indication of temperature inside the body, and system performance and safety is governed primarily by the highest temperature, encountered usually at the core of the body. This paper presents a technique to non-invasively determine the internal temperature based on the theoretical relationship between the core temperature and surface temperature distribution on the outside of a heat-generating solid body as functions of time. Experiments using infrared thermography of the outside surface of a thermal test cell in a variety of heating and cooling conditions demonstrate good agreement of the predicted core temperature as a function of time with actual core temperature measurement using an embedded thermocouple. This paper demonstrates a capability to thermally probe inside solid bodies in a non-invasive fashion. This directly benefits the accurate performance prediction and control of a variety of engineering systems where the time-varying core temperature plays a key role.

A model for osmium isotopic evolution of metallic solids at the core-mantle boundary

NASA Astrophysics Data System (ADS)

Humayun, Munir

2011-03-01

Some plumes are thought to originate at the core-mantle boundary, but geochemical evidence of core-mantle interaction is limited to Os isotopes in samples from Hawaii, Gorgona (89 Ma), and Kostomuksha (2.7 Ga). The Os isotopes have been explained by physical entrainment of Earth's liquid outer core into mantle plumes. This model has come into conflict with geophysical estimates of the timing of core formation, high-pressure experimental determinations of the solid metal-liquid metal partition coefficients (D), and the absence of expected 182W anomalies. A new model is proposed where metallic liquid from the outer core is partially trapped in a compacting cumulate pile of Fe-rich nonmetallic precipitates (FeO, FeS, Fe3Si, etc.) at the top of the core and undergoes fractional crystallization precipitating solid metal grains, followed by expulsion of the residual metallic liquid back to the outer core. The Os isotopic composition of the solids and liquids in the cumulate pile is modeled as a function of the residual liquid remaining and the emplacement age using 1 bar D values, with variable amounts of oxygen (0-10 wt %) as the light element. The precipitated solids evolve Os isotope compositions that match the trends for Hawaii (at an emplacement age of 3.5-4.5 Ga; 5%-10% oxygen) and Gorgona (emplacement age < 1.5 Ga; 0%-5% oxygen). The Fe-rich matrix of the cumulate pile dilutes the precipitated solid metal decoupling the Fe/Mn ratio from Os and W isotopes. The advantages to using precipitated solid metal as the Os host include a lower platinum group element and Ni content to the mantle source region relative to excess iron, miniscule anomalies in 182W (<0.1 ɛ), and no effects for Pb isotopes, etc. A gradual thermomechanical erosion of the cumulate pile results in incorporation of this material into the base of the mantle, where mantle plumes subsequently entrain it. Fractional crystallization of metallic liquids within the CMB provides a consistent explanation of both Os isotope correlations, Os-W isotope systematics, and Fe/Mn evidence for core-mantle interaction over the entire Hawaiian source.

High power solid state laser modulator

DOEpatents

Birx, Daniel L.; Ball, Don G.; Cook, Edward G.

2004-04-27

A multi-stage magnetic modulator provides a pulse train of .+-.40 kV electrical pulses at a 5-7 kHz repetition rate to a metal vapor laser. A fractional turn transformer steps up the voltage by a factor of 80 to 1 and magnetic pulse compression is used to reduce the pulse width of the pulse train. The transformer is fabricated utilizing a rod and plate stack type of construction to achieve a high packing factor. The pulses are controlled by an SCR stack where a plurality of SCRs are electrically connected in parallel, each SCR electrically connected to a saturable inductor, all saturable inductors being wound on the same core of magnetic material for enhanced power handling characteristics.

Thermal Hydraulics Design and Analysis Methodology for a Solid-Core Nuclear Thermal Rocket Engine Thrust Chamber

NASA Technical Reports Server (NTRS)

Wang, Ten-See; Canabal, Francisco; Chen, Yen-Sen; Cheng, Gary; Ito, Yasushi

2013-01-01

Nuclear thermal propulsion is a leading candidate for in-space propulsion for human Mars missions. This chapter describes a thermal hydraulics design and analysis methodology developed at the NASA Marshall Space Flight Center, in support of the nuclear thermal propulsion development effort. The objective of this campaign is to bridge the design methods in the Rover/NERVA era, with a modern computational fluid dynamics and heat transfer methodology, to predict thermal, fluid, and hydrogen environments of a hypothetical solid-core, nuclear thermal engine the Small Engine, designed in the 1960s. The computational methodology is based on an unstructured-grid, pressure-based, all speeds, chemically reacting, computational fluid dynamics and heat transfer platform, while formulations of flow and heat transfer through porous and solid media were implemented to describe those of hydrogen flow channels inside the solid24 core. Design analyses of a single flow element and the entire solid-core thrust chamber of the Small Engine were performed and the results are presented herein

A Small Fission Power System with Stirling Power Conversion for NASA Science Missions

NASA Technical Reports Server (NTRS)

Mason, Lee; Carmichael, Chad

2011-01-01

In early 2010, a joint National Aeronautics and Space Administration (NASA) and Department of Energy (DOE) study team developed a concept for a 1 kWe Fission Power System with a 15-year design life that could be available for a 2020 launch to support future NASA science missions. The baseline concept included a solid block uranium-molybdenum reactor core with embedded heat pipes and distributed thermoelectric converters directly coupled to aluminum radiator fins. A short follow-on study was conducted at NASA Glenn Research Center (GRC) to evaluate an alternative power conversion approach. The GRC study considered the use of free-piston Stirling power conversion as a substitution to the thermoelectric converters. The resulting concept enables a power increase to 3 kWe with the same reactor design and scalability to 10 kW without changing the reactor technology. This paper presents the configuration layout, system performance, mass summary, and heat transfer analysis resulting from the study.

Thermal Evolution of Earht's Core during Accretion: a Preliminary Solid Inner Core at the End of Accrfetion.

NASA Astrophysics Data System (ADS)

Arkani-Hamed, J.

2015-12-01

Growth of an inner core has conventionally been related to core cooling blow the liquidus of iron. It is however possible that the core of the proto-Earth solidifies upon pressure increase during accretion. The lithostatic pressure in the proto-Earth increases immediately after merging each impactor, and the pressure-dependent liquidus of iron may supersede the temperature near the center resulting in a solid inner core. Assuming that Earth is formed by accreting a few dozen Moon to Mars size planetary embryos, the thermal evolution of the proto-Earth's core is investigated during accretion. The collision of an embryo heats the Earth differentially and the rotating low-viscosity, differentially heated core stratifies, creating a spherically symmetric stable and radially increasing temperature distribution. Convection occurs in the outer core while heat transfers by conduction in deeper parts. It is assumed that the iron core of an embryo pools at the bottom of partially molten mantle and thermally equilibrates with surroundings. It then descends as an iron diapir in the solid silicate mantle, while releasing its gravitational energy. Depending on its temperature when arrives at the core mantle boundary, it may spread on the core creating a hot layer or plunge into the core and descend to a neutrally buoyant level while further releasing its gravitational energy. A few dozen thermal evolution models of the core are investigates to examine effects of major parameters such as: total number of impacting embryos; partitioning of the gravitational energy released during the descent of the diaper in the mantle (between the silicate mantle and the iron diaper), and in the core (between the proto-Earth's core and that of the embryo); and gravitational energy and latent heat released due to the core solidification. All of the models predict a large solid inner core, about 1500 to 2000 km in radius, at the end of accretion.

Isostructural solid-solid phase transition in monolayers of soft core-shell particles at fluid interfaces: structure and mechanics.

PubMed

Rey, Marcel; Fernández-Rodríguez, Miguel Ángel; Steinacher, Mathias; Scheidegger, Laura; Geisel, Karen; Richtering, Walter; Squires, Todd M; Isa, Lucio

2016-04-21

We have studied the complete two-dimensional phase diagram of a core-shell microgel-laden fluid interface by synchronizing its compression with the deposition of the interfacial monolayer. Applying a new protocol, different positions on the substrate correspond to different values of the monolayer surface pressure and specific area. Analyzing the microstructure of the deposited monolayers, we discovered an isostructural solid-solid phase transition between two crystalline phases with the same hexagonal symmetry, but with two different lattice constants. The two phases corresponded to shell-shell and core-core inter-particle contacts, respectively; with increasing surface pressure the former mechanically failed enabling the particle cores to come into contact. In the phase-transition region, clusters of particles in core-core contacts nucleate, melting the surrounding shell-shell crystal, until the whole monolayer moves into the second phase. We furthermore measured the interfacial rheology of the monolayers as a function of the surface pressure using an interfacial microdisk rheometer. The interfaces always showed a strong elastic response, with a dip in the shear elastic modulus in correspondence with the melting of the shell-shell phase, followed by a steep increase upon the formation of a percolating network of the core-core contacts. These results demonstrate that the core-shell nature of the particles leads to a rich mechanical and structural behavior that can be externally tuned by compressing the interface, indicating new routes for applications, e.g. in surface patterning or emulsion stabilization.

Core Formation Process and Light Elements in the Planetary Core

NASA Astrophysics Data System (ADS)

Ohtani, E.; Sakairi, T.; Watanabe, K.; Kamada, S.; Sakamaki, T.; Hirao, N.

2015-12-01

Si, O, and S are major candidates for light elements in the planetary core. In the early stage of the planetary formation, the core formation started by percolation of the metallic liquid though silicate matrix because Fe-S-O and Fe-S-Si eutectic temperatures are significantly lower than the solidus of the silicates. Therefore, in the early stage of accretion of the planets, the eutectic liquid with S enrichment was formed and separated into the core by percolation. The major light element in the core at this stage will be sulfur. The internal pressure and temperature increased with the growth of the planets, and the metal component depleted in S was molten. The metallic melt contained both Si and O at high pressure in the deep magma ocean in the later stage. Thus, the core contains S, Si, and O in this stage of core formation. Partitioning experiments between solid and liquid metals indicate that S is partitioned into the liquid metal, whereas O is weakly into the liquid. Partitioning of Si changes with the metallic iron phases, i.e., fcc iron-alloy coexisting with the metallic liquid below 30 GPa is depleted in Si. Whereas hcp-Fe alloy above 30 GPa coexisting with the liquid favors Si. This contrast of Si partitioning provides remarkable difference in compositions of the solid inner core and liquid outer core among different terrestrial planets. Our melting experiments of the Fe-S-Si and Fe-O-S systems at high pressure indicate the core-adiabats in small planets, Mercury and Mars, are greater than the slope of the solidus and liquidus curves of these systems. Thus, in these planets, the core crystallized at the top of the liquid core and 'snowing core' formation occurred during crystallization. The solid inner core is depleted in both Si and S whereas the liquid outer core is relatively enriched in Si and S in these planets. On the other hand, the core adiabats in large planets, Earth and Venus, are smaller than the solidus and liquidus curves of the systems. The inner core of these planets crystallized at the center of the core and it has the relatively Si rich inner core and the S enriched outer core. Based on melting and solid-liquid partitioning, the equation of state, and sound velocity of iron-light element alloys, we examined the plausible distribution of light elements in the liquid outer and solid inner cores of the terrestrial planets.

Earth's Core-Mantle equilibrium and a heat sink at the Core Mantle Boundary

NASA Astrophysics Data System (ADS)

Alfe, D.; Pozzo, M.; Davies, C. J.; Gubbins, D.

2016-12-01

Chemical equilibrium between the two sides of the core mantle boundary (CMB) has longbeen debated. If the core is well mixed and in equilibrium with the inner coredisequilibrium at the CMB seems inevitable. Indeed, a number of experiments pointto a possible non-equilibrium configuration in which the core liquid iron mixture wouldbe undersaturated in oxygen. As discussed by several authors, this chemical imbalancecould result in the formation of an oxygen rich layer at the top of the core, and astratification, which could explain a seismic anomaly claimed by some authors.Here we have revisited the core-mantle equilibrium by calculating the chemical potentialof FeO in both liquid iron mixtures and solid Periclase at CMB conditions, usingfirst principles methods based on quantum mechanics and standard statistical mechanics.We find that FeO is favoured in the liquid mixture, with an equilibrium O concentrationthat is much larger than that of the bulk core. In addition, we find that the heat ofreaction of the FeO dissolution form the mantle to the core is positive, making thereaction endothermic, and therefore providing a heat sink at the top of the core.The power lost in the heat sink depends on the rate of FeO dissolution, and we discussa scenario which could result in a heat sink of several TW. This sink would absorbsome of the heat conducted along the core adiabat and reduce the CMB heat flux.

Top-down freezing in a Fe-FeS core and Ganymede's present-day magnetic field

NASA Astrophysics Data System (ADS)

Rückriemen, Tina; Breuer, Doris; Spohn, Tilman

2018-06-01

Ganymede's core most likely possesses an active dynamo today, which produces a magnetic field at the surface of ∼ 719 nT. Thermochemical convection triggered by cooling of the core is a feasible power source for the dynamo. Experiments of different research groups indicate low pressure gradients of the melting temperatures for Fe-FeS core alloys at pressures prevailing in Ganymede's core ( < 10 GPa). This may entail that the core crystallizes from the top instead of from the bottom as is expected for Earth's core. Depending on the core sulfur concentration being more iron- or more sulfur-rich than the eutectic concentration either snowing iron crystals or a solid FeS layer can form at the top of the core. We investigate whether these two core crystallization scenarios are capable of explaining Ganymede's present magnetic activity. To do so, we set up a parametrized one-dimensional thermal evolution model. We explore a wide range of parameters by running a large set of Monte Carlo simulations. Both freezing scenarios can explain Ganymede's present-day magnetic field. Dynamos of iron snow models are rather young ( < 1 Gyr), whereas dynamos below the FeS layer can be both young and much older ( ∼ 3.8 Gyr). Successful models preferably contain less radiogenic heat sources in the mantle than the chondritic abundance and show a correlation between the reference viscosity in the mantle and the initial core sulfur concentration.

Elastic and plastic buckling of simply supported solid-core sandwich plates in compression

NASA Technical Reports Server (NTRS)

Seide, Paul; Stowell, Elbridge Z

1950-01-01

A solution is presented for the problem of the compressive buckling of simply supported, flat, rectangular, solid-core sandwich plates stressed either in the elastic range or in the plastic range. Charts for the analysis of long sandwich plates are presented for plates having face materials of 24s-t3 aluminum alloy, 76s-t6 alclad aluminum alloy, and stainless steel. A comparison of computed and experimental buckling stresses of square solid-core sandwich plates indicates fair agreement between theory and experiment.

Modeling of Thermal Phase Noise in a Solid Core Photonic Crystal Fiber-Optic Gyroscope.

PubMed

Song, Ningfang; Ma, Kun; Jin, Jing; Teng, Fei; Cai, Wei

2017-10-26

A theoretical model of the thermal phase noise in a square-wave modulated solid core photonic crystal fiber-optic gyroscope has been established, and then verified by measurements. The results demonstrate a good agreement between theory and experiment. The contribution of the thermal phase noise to the random walk coefficient of the gyroscope is derived. A fiber coil with 2.8 km length is used in the experimental solid core photonic crystal fiber-optic gyroscope, showing a random walk coefficient of 9.25 × 10 -5 deg/√h.

Feasibility study of a small, thorium-based fission power system for space and terrestrial applications

NASA Astrophysics Data System (ADS)

Worrall, Michael Jason

One of the current challenges facing space exploration is the creation of a power source capable of providing useful energy for the entire duration of a mission. Historically, radioisotope batteries have been used to provide load power, but this conventional system may not be capable of sustaining continuous power for longer duration missions. To remedy this, many forays into nuclear powered spacecraft have been investigated, but no robust system for long-term power generation has been found. In this study, a novel spin on the traditional fission power system that represents a potential optimum solution is presented. By utilizing mature High Temperature Gas Reactor (HTGR) technology in conjunction with the capabilities of the thorium fuel cycle, we have created a light-weight, long-term power source capable of a continuous electric power output of up to 70kW for over 15 years. This system relies upon a combination of fissile, highly-enriched uranium dioxide and fertile thorium carbide Tri-Structural Isotropic (TRISO) fuel particles embedded in a hexagonal beryllium oxide matrix. As the primary fissile material is consumed, the fertile material breeds new fissile material leading to more steady fuel loading over the lifetime of the core. Reactor control is achieved through an innovative approach to the conventional boron carbide neutron absorber by utilizing sections of borated aluminum placed in rotating control drums within the reflector. Borated aluminum allows for much smaller boron concentrations, thus eliminating the potential for 10B(n,alpha)6Li heating issues that are common in boron carbide systems. A wide range of other reactivity control systems are also investigated, such as a radially-split rotating reflector. Lastly, an extension of the design to a terrestrial based system is investigated. In this system, uranium enrichment is dropped to 20 percent in order to meet current regulations, a solid uranium-zirconium hydride fissile driver replaces the uranium dioxide TRISO particles, and the moderating material is changed from beryllium oxide to graphite. These changes result in an increased core size, but the same long-term power generation potential is achieved. Additionally, small amounts of erbium are added to the hydride matrix to further extend core lifetime.

Solid0Core Heat-Pipe Nuclear Batterly Type Reactor

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

Ehud Greenspan

This project was devoted to a preliminary assessment of the feasibility of designing an Encapsulated Nuclear Heat Source (ENHS) reactor to have a solid core from which heat is removed by liquid-metal heat pipes (HP).

Chemical and thermal stability of core-shelled magnetite nanoparticles and solid silica

NASA Astrophysics Data System (ADS)

Cendrowski, Krzysztof; Sikora, Pawel; Zielinska, Beata; Horszczaruk, Elzbieta; Mijowska, Ewa

2017-06-01

Pristine nanoparticles of magnetite were coated by solid silica shell forming core/shell structure. 20 nm thick silica coating significantly enhanced the chemical and thermal stability of the iron oxide. Chemical and thermal stability of this structure has been compared to the magnetite coated by mesoporous shell and pristine magnetite nanoparticles. It is assumed that six-membered silica rings in a solid silica shell limit the rate of oxygen diffusion during thermal treatment in air and prevent the access of HCl molecules to the core during chemical etching. Therefore, the core/shell structure with a solid shell requires a longer time to induce the oxidation of iron oxide to a higher oxidation state and, basically, even strong concentrated acid such as HCl is not able to dissolve it totally in one month. This leads to the desired performance of the material in potential applications such as catalysis and environmental protection.

Lunar Rotation and the Lunar Interior

NASA Technical Reports Server (NTRS)

Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.; Dickey, J. O.

2003-01-01

Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/ solid-mantle boundary, and tidal Love number k2. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) and fluid core moment of inertia. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core plus Love number. Past detection of CMB flattening has been marginal but is improving, while direct detection of the core moment has not yet been achieved. Three decades of Lunar Laser Ranging (LLR) data are analyzed using a weighted least-squares approach. The lunar solution parameters include dissipation at the fluid-core/solid-mantle boundary, tidal dissipation, dissipation-related coefficients for rotation and orientation terms, potential Love number k2, a correction to the constant term in the tilt of the equator to the ecliptic which is meant to approximate the influence of core-mantle boundary flattening, and displacement Love numbers h2 and l2. Several solutions, with different combinations of solution parameters and constraints, are considered.

Supercontinuum generation covering the entire 0.4-5 µm transmission window in a tapered ultra-high numerical aperture all-solid fluorotellurite fiber

NASA Astrophysics Data System (ADS)

Jia, Z. X.; Yao, C. F.; Jia, S. J.; Wang, F.; Wang, S. B.; Zhao, Z. P.; Liao, M. S.; Qin, G. S.; Hu, L. L.; Ohishi, Y.; Qin, W. P.

2018-02-01

Enormous efforts have been made to realize supercontinuum (SC) generation covering the entire transmission window of fiber materials for their wide applications in many fields. Here we demonstrate ultra-broadband SC generation from 400 to 5140 nm in a tapered ultra-high numerical aperture (NA) all-solid fluorotellurite fiber pumped by a 1560 nm mode-locked fiber laser. The fluorotellurite fibers are fabricated using a rod-in-tube method. The core and cladding materials are TeO2-BaF2-Y2O3- and TeO2-modified fluoroaluminate glasses, respectively, which have large refractive index contrast and similar thermal expansion coefficients and softening temperatures. The NA at 3200 nm of the fluorotellurite fiber is about 1.11. Furthermore, tapered fluorotellurite fibers are prepared using an elongation machine. SC generation covering the entire 0.4-5 µm transmission window is achieved in a tapered fluorotellurite fiber for a pumping peak power of ~10.5 kW through synergetic control of dispersion, nonlinearity, confinement loss and other unexpected effects (e.g. the attachment of dust or water to the surface of the fiber core) of the fiber. Our results show that tapered ultra-high NA all-solid soft glass fibers have a potential for generating SC light covering their entire transmission window.

Titanium dioxide@polypyrrole core-shell nanowires for all solid-state flexible supercapacitors.

PubMed

Yu, Minghao; Zeng, Yinxiang; Zhang, Chong; Lu, Xihong; Zeng, Chenghui; Yao, Chenzhong; Yang, Yangyi; Tong, Yexiang

2013-11-21

Herein, we developed a facile two-step process to synthesize TiO2@PPy core-shell nanowires (NWs) on carbon cloth and reported their improved electrochemical performance for flexible supercapacitors (SCs). The fabricated solid-state SC device based on TiO2@PPy core-shell NWs not only has excellent flexibility, but also exhibits remarkable electrochemical performance.

Apparatus and Method for Increasing the Diameter of Metal Alloy Wires Within a Molten Metal Pool

DOEpatents

Hartman, Alan D.; Argetsinger, Edward R.; Hansen, Jeffrey S.; Paige, Jack I.; King, Paul E.; Turner, Paul C.

2002-01-29

In a dip forming process the core material to be coated is introduced directly into a source block of coating material eliminating the need for a bushing entrance component. The process containment vessel or crucible is heated so that only a portion of the coating material becomes molten, leaving a solid portion of material as the entrance port of, and seal around, the core material. The crucible can contain molten and solid metals and is especially useful when coating core material with reactive metals. The source block of coating material has been machined to include a close tolerance hole of a size and shape to closely fit the core material. The core material moves first through the solid portion of the source block of coating material where the close tolerance hole has been machined, then through a solid/molten interface, and finally through the molten phase where the diameter of the core material is increased. The crucible may or may not require water-cooling depending upon the type of material used in crucible construction. The system may operate under vacuum, partial vacuum, atmospheric pressure, or positive pressure depending upon the type of source material being used.

Apparatus and method for increasing the diameter of metal alloy wires within a molten metal pool

DOEpatents

Hartman, Alan D.; Argetsinger, Edward R.; Hansen, Jeffrey S.; Paige, Jack I.; King, Paul E.; Turner, Paul C.

2002-01-29

In a dip forming process the core material to be coated is introduced directly into a source block of coating material eliminating the need for a bushing entrance component. The process containment vessel or crucible is heated so that only a portion of the coating material becomes molten, leaving a solid portion of material as the entrance port of, and seal around, the core material. The crucible can contain molten and solid metals and is especially useful when coating core material with reactive metals. The source block of coating material has been machined to include a close tolerance hole of a size and shape to closely fit the core material. The core material moves first through the solid portion of the source block of coating material where the close tolerance hole has been machined, then through a solid/molten interface, and finally through the molten phase where the diameter of the core material is increased. The crucible may or may not require water-cooling depending upon the type of material used in crucible construction. The system may operate under vacuum, partial vacuum, atmospheric pressure, or positive pressure depending upon the type of source material being used.

A Boiling-Potassium Fluoride Reactor for an Artificial-Gravity NEP Vehicle

NASA Technical Reports Server (NTRS)

Sorensen, Kirk; Juhasz, Albert

2007-01-01

Several years ago a rotating manned spacecraft employing nuclear-electric propulsion was examined for Mars exploration. The reactor and its power conversion system essentially served as the counter-mass to an inflatable manned module. A solid-core boiling potassium reactor based on the MPRE concept of the 1960s was baselined in that study. This paper proposes the use of a liquid-fluoride reactor, employing direct boiling of potassium in the core, as a means to overcome some of the residual issues with the MPRE reactor concept. Several other improvements to the rotating Mars vehicle are proposed as well, such as Canfield joints to enable the electric engines to track the inertial thrust vector during rotation, and innovative "cold-ion" engine technologies to improve engine performance.

Modeling an in-register, parallel "iowa" aβ fibril structure using solid-state NMR data from labeled samples with rosetta.

PubMed

Sgourakis, Nikolaos G; Yau, Wai-Ming; Qiang, Wei

2015-01-06

Determining the structures of amyloid fibrils is an important first step toward understanding the molecular basis of neurodegenerative diseases. For β-amyloid (Aβ) fibrils, conventional solid-state NMR structure determination using uniform labeling is limited by extensive peak overlap. We describe the characterization of a distinct structural polymorph of Aβ using solid-state NMR, transmission electron microscopy (TEM), and Rosetta model building. First, the overall fibril arrangement is established using mass-per-length measurements from TEM. Then, the fibril backbone arrangement, stacking registry, and "steric zipper" core interactions are determined using a number of solid-state NMR techniques on sparsely (13)C-labeled samples. Finally, we perform Rosetta structure calculations with an explicitly symmetric representation of the system. We demonstrate the power of the hybrid Rosetta/NMR approach by modeling the in-register, parallel "Iowa" mutant (D23N) at high resolution (1.2Å backbone rmsd). The final models are validated using an independent set of NMR experiments that confirm key features. Copyright © 2015 Elsevier Ltd. All rights reserved.

Suspended core subwavelength fibers: towards practical designs for low-loss terahertz guidance.

PubMed

Rozé, Mathieu; Ung, Bora; Mazhorova, Anna; Walther, Markus; Skorobogatiy, Maksim

2011-05-09

In this work we report two designs of subwavelength fibers packaged for practical terahertz wave guiding. We describe fabrication, modeling and characterization of microstructured polymer fibers featuring a subwavelength-size core suspended in the middle of a large porous outer cladding. This design allows convenient handling of the subwavelength fibers without distorting their modal profile. Additionally, the air-tight porous cladding serves as a natural enclosure for the fiber core, thus avoiding the need for a bulky external enclosure for humidity-purged atmosphere. Fibers of 5 mm and 3 mm in outer diameters with a 150 µm suspended solid core and a 900 µm suspended porous core respectively, were obtained by utilizing a combination of drilling and stacking techniques. Characterization of the fiber optical properties and the subwavelength imaging of the guided modes were performed using a terahertz near-field microscopy setup. Near-field imaging of the modal profiles at the fiber output confirmed the effectively single-mode behavior of such waveguides. The suspended core fibers exhibit transmission from 0.10 THz to 0.27 THz (larger core), and from 0.25 THz to 0.51 THz (smaller core). Due to the large fraction of power that is guided in the holey cladding, fiber propagation losses as low as 0.02 cm(-1) are demonstrated specifically for the small core fiber. Low-loss guidance combined with the core isolated from environmental perturbations make these all-dielectric fibers suitable for practical terahertz imaging and sensing applications. © 2011 Optical Society of America

An integral nuclear power and propulsion system concept

NASA Astrophysics Data System (ADS)

Choong, Phillip T.; Teofilo, Vincent L.; Begg, Lester L.; Dunn, Charles; Otting, William

An integral space power concept provides both the electrical power and propulsion from a common heat source and offers superior performance capabilities over conventional orbital insertion using chemical propulsion systems. This paper describes a hybrid (bimodal) system concept based on a proven, inherently safe solid fuel form for the high temperature reactor core operation and rugged planar thermionic energy converter for long-life steady state electric power production combined with NERVA-based rocket technology for propulsion. The integral system is capable of long-life power operation and multiple propulsion operations. At an optimal thrust level, the integral system can maintain the minimal delta-V requirement while minimizing the orbital transfer time. A trade study comparing the overall benefits in placing large payloads to GEO with the nuclear electric propulsion option shows superiority of nuclear thermal propulsion. The resulting savings in orbital transfer time and the substantial reduction of overall lift requirement enables the use of low-cost launchers for several near-term military satellite missions.

Preliminary Results on Lunar Interior Properties from the GRAIL Mission

NASA Technical Reports Server (NTRS)

Williams, James G.; Konopliv, Alexander S.; Asmar, Sami W.; Lemoine, H. Jay; Melosh, H. Jay; Neumann, Gregory A.; Phillips, Roger J.; Smith, David E.; Solomon, Sean C.; Watkins, Michael M.;

Coated armor system and process for making the same

DOEpatents

Chu, Henry S.; Lillo, Thomas M.; McHugh, Kevin M.

2010-11-23

An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

Modeling of Thermal Phase Noise in a Solid Core Photonic Crystal Fiber-Optic Gyroscope

PubMed Central

Song, Ningfang; Ma, Kun; Jin, Jing; Teng, Fei; Cai, Wei

2017-01-01

A theoretical model of the thermal phase noise in a square-wave modulated solid core photonic crystal fiber-optic gyroscope has been established, and then verified by measurements. The results demonstrate a good agreement between theory and experiment. The contribution of the thermal phase noise to the random walk coefficient of the gyroscope is derived. A fiber coil with 2.8 km length is used in the experimental solid core photonic crystal fiber-optic gyroscope, showing a random walk coefficient of 9.25 × 10−5 deg/h. PMID:29072605

KSC-2011-4960

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- Workers deliver NASA's Juno spacecraft to Astrotech's Hazardous Processing Facility in Titusville, Fla., for fueling. The spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4959

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- Workers deliver NASA's Juno spacecraft to Astrotech's Hazardous Processing Facility in Titusville, Fla., for fueling. The spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-6318

NASA Image and Video Library

2011-08-05

CAPE CANAVERAL, Fla. -- Reflected in water surrounding Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida, fire lights up a crystal-clear blue sky as a United Launch Alliance Atlas V rocket lofts NASA's Juno planetary probe into space. Liftoff was at 12:25 p.m. EDT Aug. 5. The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information, visit www.nasa.gov/juno. Photo credit: Courtesy Scott Andrews

KSC-2011-6313

NASA Image and Video Library

2011-08-05

CAPE CANAVERAL, Fla. -- Fire lights up a crystal-clear blue sky on Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida as a United Launch Alliance Atlas V rocket lofts NASA's Juno planetary probe into space. Liftoff was at 12:25 p.m. EDT Aug. 5. The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information, visit www.nasa.gov/juno. Photo credit: NASA/Tony Gray and Don Kight

KSC-2011-6311

NASA Image and Video Library

2011-08-05

CAPE CANAVERAL, Fla. -- Fire lights up a crystal-clear blue sky on Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida as a United Launch Alliance Atlas V rocket lofts NASA's Juno planetary probe into space. Liftoff was at 12:25 p.m. EDT Aug. 5. The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information, visit www.nasa.gov/juno. Photo credit: NASA/Tony Gray and Don Kight

KSC-2011-6317

NASA Image and Video Library

2011-08-05

CAPE CANAVERAL, Fla. -- Fire lights up a crystal-clear blue sky on Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida as a United Launch Alliance Atlas V rocket lofts NASA's Juno planetary probe into space. Liftoff was at 12:25 p.m. EDT Aug. 5. The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information, visit www.nasa.gov/juno. Photo credit: Courtesy Scott Andrews

KSC-2011-6312

NASA Image and Video Library

2011-08-05

CAPE CANAVERAL, Fla. -- Fire lights up a crystal-clear blue sky on Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida as a United Launch Alliance Atlas V rocket lofts NASA's Juno planetary probe into space. Liftoff was at 12:25 p.m. EDT Aug. 5. The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information, visit www.nasa.gov/juno. Photo credit: NASA/Tony Gray and Don Kight

Tier-2 Optimisation for Computational Density/Diversity and Big Data

NASA Astrophysics Data System (ADS)

Fay, R. B.; Bland, J.

2014-06-01

As the number of cores on chip continues to trend upwards and new CPU architectures emerge, increasing CPU density and diversity presents multiple challenges to site administrators. These include scheduling for massively multi-core systems (potentially including Graphical Processing Units (GPU), integrated and dedicated) and Many Integrated Core (MIC)) to ensure a balanced throughput of jobs while preserving overall cluster throughput, as well as the increasing complexity of developing for these heterogeneous platforms, and the challenge in managing this more complex mix of resources. In addition, meeting data demands as both dataset sizes increase and as the rate of demand scales with increased computational power requires additional performance from the associated storage elements. In this report, we evaluate one emerging technology, Solid State Drive (SSD) caching for RAID controllers, with consideration to its potential to assist in meeting evolving demand. We also briefly consider the broader developing trends outlined above in order to identify issues that may develop and assess what actions should be taken in the immediate term to address those.

Titanium dioxide@polypyrrole core-shell nanowires for all solid-state flexible supercapacitors

NASA Astrophysics Data System (ADS)

Yu, Minghao; Zeng, Yinxiang; Zhang, Chong; Lu, Xihong; Zeng, Chenghui; Yao, Chenzhong; Yang, Yangyi; Tong, Yexiang

2013-10-01

Herein, we developed a facile two-step process to synthesize TiO2@PPy core-shell nanowires (NWs) on carbon cloth and reported their improved electrochemical performance for flexible supercapacitors (SCs). The fabricated solid-state SC device based on TiO2@PPy core-shell NWs not only has excellent flexibility, but also exhibits remarkable electrochemical performance.Herein, we developed a facile two-step process to synthesize TiO2@PPy core-shell nanowires (NWs) on carbon cloth and reported their improved electrochemical performance for flexible supercapacitors (SCs). The fabricated solid-state SC device based on TiO2@PPy core-shell NWs not only has excellent flexibility, but also exhibits remarkable electrochemical performance. Electronic supplementary information (ESI) available: Experimental details, XRD pattern, FT-IR absorption spectrum and CV curves of TiO2@PPy NWs, and SEM images of the PPy. See DOI: 10.1039/c3nr03578f

A Large Solid Inner Core at Mercury

NASA Astrophysics Data System (ADS)

Genova, A.; Goossens, S.; Mazarico, E.; Lemoine, F. G.; Neumann, G. A.; Kuang, W.; Sabaka, T. J.; Smith, D. E.; Zuber, M. T.

2018-05-01

New measurements of the polar moments of inertia of the whole planet and of the outer layers (crust+mantle), and simulations of Mercury’s magnetic field dynamo suggest the presence of a solid inner core with a Ric 0.3-0.5 Roc.

Multiple Experimental Efforts to Understand the Structure and Dynamics of Earth's Core

NASA Astrophysics Data System (ADS)

Fei, Y.; Han, L.; Bennett, N.; Hou, M.; Kuwayama, Y.; Huang, H.

2014-12-01

It requires integration of data from different types of high-pressure experiments to understand the structure and dynamics of Earth's core. In particular, measurements of physical properties and element partitioning in systems relevant to the core provide complementary data to narrow down the range of possible core compositions. We have performed both static and dynamic compression experiments and combined results from these with literature data to establish a reliable thermal equation of state of iron. This allows us to precisely determine the density deficit in the solid inner core. The combination of density and sound velocity measurements for both solid and liquid iron and its alloys provide tight constraints on the density deficit in the liquid outer core and the amount of sulphur required to match the geophysical observations. We then conducted element-partitioning experiments between solid and liquid iron in both multi-anvil apparatus and the laser-heated diamond-anvil cell to determine the sulphur, silicon, and oxygen partitioning between the liquid outer core and solid inner core. We present newly developed high-pressure experimental and nano-scale analytical techniques that allow us to simulate the conditions of the inner core boundary (ICB) and analyze the chemical compositions of coexisting phases in the recovered samples. We have established protocols to obtain high-quality partitioning data in the laser-heating diamond-anvil cell combined with FIB/SEM crossbeam technology. The partitioning data obtained up to at least 200 GPa provide additional criteria to explain the observed density and velocity jumps at the ICB.

Distributed gas detection system and method

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

Challener, William Albert; Palit, Sabarni; Karp, Jason Harris

A distributed gas detection system includes one or more hollow core fibers disposed in different locations, one or more solid core fibers optically coupled with the one or more hollow core fibers and configured to receive light of one or more wavelengths from a light source, and an interrogator device configured to receive at least some of the light propagating through the one or more solid core fibers and the one or more hollow core fibers. The interrogator device is configured to identify a location of a presence of a gas-of-interest by examining absorption of at least one of themore » wavelengths of the light at least one of the hollow core fibers.« less

Properties of the Lunar Interior: Preliminary Results from the GRAIL Mission

NASA Technical Reports Server (NTRS)

Williams, James G.; Konopliv, Alexander S.; Asmar, Sami W.; Lemoine, Frank G.; Melosh, H. Jay; Neumann, Gregory A.; Phillips, Roger J.; Smith, David E.; Solomon, Sean C.; Watkins, Michael M.;

Methods of producing armor systems, and armor systems produced using such methods

DOEpatents

Chu, Henry S; Lillo, Thomas M; McHugh, Kevin M

2013-02-19

An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

New interpretation of data of the Earth's solid core

NASA Astrophysics Data System (ADS)

Guliyev, H. H.

2017-06-01

The commonly accepted scientific opinions on the inner core as the deformable solid globe are based on the solution of the problem on the distribution of elastic parameters in the inner structures of the Earth. The given solution is obtained within the necessary integral conditions on its self-weight, moment of inertia concerning the axes of rotation and periods of free oscillations of the Earth. It is shown that this solution does not satisfy the mechanics of the deformable solid body with sufficient local conditions following from basic principles concerning the strength, stability and actuality of velocities of propagation of elastic waves. The violation of local conditions shows that the inner core cannot exist in the form of the deformable solid body within the commonly accepted elastic parameters.

Nuclear propulsion - A vital technology for the exploration of Mars and the planets beyond

NASA Technical Reports Server (NTRS)

Borowski, Stanley K.

1989-01-01

The physics and technology issues and performance potential of various direct thrust fission and fusion propulsion concepts are examined. Next to chemical propulsion the solid core fission thermal rocket (SCR) is the only other concept to be experimentally tested at the power (approx 1.5 to 5.0 GW) and thrust levels (approx 0.33 to 1.11 MN) required for manned Mars missions. With a specific impulse of approx 850 s, the SCR can perform various near-earth, cislunar and interplanetary missions with lower mass and cost requirements than its chemical counterpart. The gas core fission thermal rocket, with a specific power and impulse of approx 50 kW/kg and 5000 s offers the potential for quick courier trips to Mars (of about 80 days) or longer duration exploration cargo missions (lasting about 280 days) with starting masses of about 1000 m tons. Convenient transportation to the outer Solar System will require the development of magnetic and inertial fusion rockets (IFRs). Possessing specific powers and impulses of approx 100 kW/kg and 200-300 kilosecs, IFRs will usher in the era of the true Solar System class spaceship. Even Pluto will be accessible with roundtrip times of less than 2 years and starting masses of about 1500 m tons.

Nuclear propulsion: a vital technology for the exploration of Mars and the planets beyond

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

Borowski, S.K.

1988-01-01

The physics and technology issues and performance potential of various direct thrust fission and fusion propulsion concepts are examined. Next to chemical propulsion the solid core fission thermal rocket (SCR) is the olny other concept to be experimentally tested at the power (approx 1.5 to 5.0 GW) and thrust levels (approx 0.33 to 1.11 MN) required for manned Mars missions. With a specific impulse of approx 850 s, the SCR can perform various near-Earth, cislunar and interplanetary missions with lower mass and cost requirements than its chemical counterpart. The gas core fission thermal rocket, with a specific power and impulsemore » of approx 50 kW/kg and 5000 s offers the potential for quick courier trips to Mars (of about 80 days) or longer duration exploration cargo missions (lasting about 280 days) with starting masses of about 1000 m tons. Convenient transportation to the outer Solar System will require the development of magnetic and inertial fusion rockets (IFRs). Possessing specific powers and impulses of approx 100 kW/kg and 200-300 kilosecs, IFRs will usher in the era of the true Solar System class speceship. Even Pluto will be accessible with roundtrip times of less than 2 years and starting masses of about 1500 m tons.« less

Nuclear propulsion: A vital technology for the exploration of Mars and the planets beyond

NASA Technical Reports Server (NTRS)

Borowski, Stanley K.

1988-01-01

The physics and technology issues and performance potential of various direct thrust fission and fusion propulsion concepts are examined. Next to chemical propulsion the solid core fission thermal rocket (SCR) is the olny other concept to be experimentally tested at the power (approx 1.5 to 5.0 GW) and thrust levels (approx 0.33 to 1.11 MN) required for manned Mars missions. With a specific impulse of approx 850 s, the SCR can perform various near-Earth, cislunar and interplanetary missions with lower mass and cost requirements than its chemical counterpart. The gas core fission thermal rocket, with a specific power and impulse of approx 50 kW/kg and 5000 s offers the potential for quick courier trips to Mars (of about 80 days) or longer duration exploration cargo missions (lasting about 280 days) with starting masses of about 1000 m tons. Convenient transportation to the outer Solar System will require the development of magnetic and inertial fusion rockets (IFRs). Possessing specific powers and impulses of approx 100 kW/kg and 200-300 kilosecs, IFRs will usher in the era of the true Solar System class speceship. Even Pluto will be accessible with roundtrip times of less than 2 years and starting masses of about 1500 m tons.

Atmospheric Mining in the Outer Solar System: Resource Capturing, Storage, and Utilization

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2014-01-01

Atmospheric mining in the outer solar system has been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as helium 3 and hydrogen can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and hydrogen (deuterium, etc.) were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses were undertaken to investigate resource capturing aspects of atmospheric mining in the outer solar system. This included the gas capturing rate for hydrogen helium 4 and helium 3, storage options, and different methods of direct use of the captured gases. Additional supporting analyses were conducted to illuminate vehicle sizing and orbital transportation issues.

Properties of iron alloys under the Earth's core conditions

NASA Astrophysics Data System (ADS)

Morard, Guillaume; Andrault, Denis; Antonangeli, Daniele; Bouchet, Johann

2014-05-01

The Earth's core is constituted of iron and nickel alloyed with lighter elements. In view of their affinity with the metallic phase, their relative high abundance in the solar system and their moderate volatility, a list of potential light elements have been established, including sulfur, silicon and oxygen. We will review the effects of these elements on different aspects of Fe-X high pressure phase diagrams under Earth's core conditions, such as melting temperature depression, solid-liquid partitioning during crystallization, and crystalline structure of the solid phases. Once extrapolated to the inner-outer core boundary, these petrological properties can be used to constrain the Earth's core properties.

Calculations of stopping powers of 100 eV-30 keV electrons in 31 elemental solids

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

Tanuma, S.; Powell, C. J.; Penn, D. R.

We present calculated electron stopping powers (SPs) for 31 elemental solids (Li, Be, glassy C, graphite, diamond, Na, Mg, K, Sc, Ti, V, Fe, Y, Zr, Nb, Mo, Ru, Rh, In, Sn, Cs, Gd, Tb, Dy, Hf, Ta, W, Re, Os, Ir, and Bi). These SPs were determined with an algorithm previously used for the calculation of electron inelastic mean free paths and from energy-loss functions (ELFs) derived from experimental optical data. The SP calculations were made for electron energies between 100 eV and 30 keV and supplement our earlier SP calculations for ten additional solids (Al, Si, Cr, Ni,more » Cu, Ge, Pd, Ag, Pt, and Au). Plots of SP versus atomic number for the group of 41 solids show clear trends. Multiple peaks and shoulders are seen that result from the contributions of valence-electron and various inner-shell excitations. Satisfactory agreement was found between the calculated SPs and values from the relativistic Bethe SP equation with recommended values of the mean excitation energy (MEE) for energies above 10 keV. We determined effective MEEs versus maximum excitation energy from the ELFs for each solid. Plots of effective MEE versus atomic number showed the relative contributions of valence-electron and different core-electron excitations to the MEE. For a maximum excitation energy of 30 keV, our effective MEEs agreed well for Be, graphite, Na, Al, and Si with recommended MEEs; a difference for Li was attributed to sample oxidation in the SP measurements for the recommended MEE. Substantially different effective MEEs were found for the three carbon allotropes (graphite, diamond, and glassy C)« less

Unidirectional photonic wire laser

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

Khalatpour, Ali; Reno, John L.; Kherani, Nazir P.

Photonic wire lasers are a new genre of lasers that have a transverse dimension much smaller than the wavelength. Unidirectional emission is highly desirable as most of the laser power will be in the desired direction. Owing to their small lateral dimension relative to the wavelength, however, the mode mostly propagates outside the solid core. Consequently, conventional approaches to attach a highly reflective element to the rear facet, whether a thin film or a distributed Bragg reflector, are not applicable. In this paper, we propose a simple and effective technique to achieve unidirectionality. Terahertz quantum-cascade lasers with distributed feedback (DFB)more » were chosen as the platform of the photonic wire lasers. Unidirectionality is achieved with a power ratio of the forward/backward of about eight, and the power of the forward-emitting laser is increased by a factor of 1.8 compared with a reference bidirectional DFB laser. Finally and furthermore, we achieved a wall plug power efficiency of ~1%.« less

Unidirectional photonic wire laser

DOE PAGES

Khalatpour, Ali; Reno, John L.; Kherani, Nazir P.; ...

2017-08-07

Photonic wire lasers are a new genre of lasers that have a transverse dimension much smaller than the wavelength. Unidirectional emission is highly desirable as most of the laser power will be in the desired direction. Owing to their small lateral dimension relative to the wavelength, however, the mode mostly propagates outside the solid core. Consequently, conventional approaches to attach a highly reflective element to the rear facet, whether a thin film or a distributed Bragg reflector, are not applicable. In this paper, we propose a simple and effective technique to achieve unidirectionality. Terahertz quantum-cascade lasers with distributed feedback (DFB)more » were chosen as the platform of the photonic wire lasers. Unidirectionality is achieved with a power ratio of the forward/backward of about eight, and the power of the forward-emitting laser is increased by a factor of 1.8 compared with a reference bidirectional DFB laser. Finally and furthermore, we achieved a wall plug power efficiency of ~1%.« less

Core-Shell Fe1- xS@Na2.9PS3.95Se0.05 Nanorods for Room Temperature All-Solid-State Sodium Batteries with High Energy Density.

PubMed

Wan, Hongli; Mwizerwa, Jean Pierre; Qi, Xingguo; Liu, Xin; Xu, Xiaoxiong; Li, Hong; Hu, Yong-Sheng; Yao, Xiayin

2018-03-27

High ionic conductivity electrolyte and intimate interfacial contact are crucial factors to realize high-performance all-solid-state sodium batteries. Na 2.9 PS 3.95 Se 0.05 electrolyte with reduced particle size of 500 nm is first synthesized by a simple liquid-phase method and exhibits a high ionic conductivity of 1.21 × 10 -4 S cm -1 , which is comparable with that synthesized with a solid-state reaction. Meanwhile, a general interfacial architecture, that is, Na 2.9 PS 3.95 Se 0.05 electrolyte uniformly anchored on Fe 1- x S nanorods, is designed and successfully prepared by an in situ liquid-phase coating approach, forming core-shell structured Fe 1- x S@Na 2.9 PS 3.95 Se 0.05 nanorods and thus realizing an intimate contact interface. The Fe 1- x S@Na 2.9 PS 3.95 Se 0.05 /Na 2.9 PS 3.95 Se 0.05 /Na all-solid-state sodium battery demonstrates high specific capacity and excellent rate capability at room temperature, showing reversible discharge capacities of 899.2, 795.5, 655.1, 437.9, and 300.4 mAh g -1 at current densities of 20, 50, 100, 150, and 200 mA g -1 , respectively. The obtained all-solid-state sodium batteries show very high energy and power densities up to 910.6 Wh kg -1 and 201.6 W kg -1 based on the mass of Fe 1- x S at current densities of 20 and 200 mA g -1 , respectively. Moreover, the reaction mechanism of Fe 1- x S is confirmed by means of ex situ X-ray diffraction techniques, showing that partially reversible reaction occurs in the Fe 1- x S electrode after the second cycle, which gives the obtained all-solid-state sodium battery an exceptional cycling stability, exhibiting a high capacity of 494.3 mAh g -1 after cycling at 100 mA g -1 for 100 cycles. This contribution provides a strategy for designing high-performance room temperature all-solid-state sodium battery.

Direct measurement of thermal conductivity in solid iron at planetary core conditions.

PubMed

Konôpková, Zuzana; McWilliams, R Stewart; Gómez-Pérez, Natalia; Goncharov, Alexander F

2016-06-02

The conduction of heat through minerals and melts at extreme pressures and temperatures is of central importance to the evolution and dynamics of planets. In the cooling Earth's core, the thermal conductivity of iron alloys defines the adiabatic heat flux and therefore the thermal and compositional energy available to support the production of Earth's magnetic field via dynamo action. Attempts to describe thermal transport in Earth's core have been problematic, with predictions of high thermal conductivity at odds with traditional geophysical models and direct evidence for a primordial magnetic field in the rock record. Measurements of core heat transport are needed to resolve this difference. Here we present direct measurements of the thermal conductivity of solid iron at pressure and temperature conditions relevant to the cores of Mercury-sized to Earth-sized planets, using a dynamically laser-heated diamond-anvil cell. Our measurements place the thermal conductivity of Earth's core near the low end of previous estimates, at 18-44 watts per metre per kelvin. The result is in agreement with palaeomagnetic measurements indicating that Earth's geodynamo has persisted since the beginning of Earth's history, and allows for a solid inner core as old as the dynamo.

Space Launch System Resource Reel 2017

NASA Image and Video Library

2017-12-01

NASA's new heavy-lift rocket, the Space Launch System, will be the most powerful rocket every built, launching astronauts in NASA's Orion spacecraft on missions into deep space. Two solid rocket boosters and four RS-25 engines will power the massive rocket, providing 8 million pounds of thrust during launch. Production and testing are underway for much of the rocket's critical hardware. With major welding complete on core stage hardware for the first integrated flight of SLS and Orion, the liquid hydrogen tank, intertank and liquid oxygen tank are ready for further outfitting. NASA's barge Pegasus has transported test hardware the first SLS hardware, the engine section to NASA's Marshall Space Flight Center in Huntsville, Alabama, for testing. In preparation for testing and handling operations, engineers have built the core stage pathfinder, to practice transport without the risk of damaging flight hardware. Integrated structural testing is complete on the top part of the rocket, including the Orion stage adapter, launch vehicle stage adapter and interim cryogenic propulsion stage. The Orion Stage Adapter for SLS's first flight, which will carry 13 CubeSats as secondary payloads, is ready to be outfitted with wiring and brackets. Once structural testing and flight hardware production are complete, the core stage will undergo "green run" testing in the B-2 test stand at NASA's Stennis Space Center in Bay St. Louis, Mississippi. For more information about SLS, visit nasa.gov/sls.

State of the metal core in nanosecond exploding wires and related phenomena

NASA Astrophysics Data System (ADS)

Sarkisov, G. S.; Sasorov, P. V.; Struve, K. W.; McDaniel, D. H.

2004-08-01

Experiments show that an expanding metal wire core that results from a nanosecond electrical explosion in vacuum consists primarily of three different states: solid, microdrop, and gas-plasma. The state of the wire core depends both on the amount of energy deposited before the voltage breakdown and on the heating conditions. For small amounts of deposited energy (on the order of solid-stage enthalpy), the wire core remains in a solid state or is partially disintegrated. For a high level of deposited energy (more than vaporization energy) the wire core is in a gas-plasma state. For an intermediate level of deposited energy (more than melting but less than vaporization), the wire disintegrates into hot liquid microdrops or clusters of submicron size. For a wire core in the cluster state, interferometry demonstrates weak (or even absent) phaseshift. Light emission shows a "firework effect"—the long late-time radiation related to the emission by the expanding cylinder of hot microparticles. For the wire core in a gas-plasma state, interferometry demonstrates a large phaseshift and a fast reduction in light emission due to adiabatic cooling of the expanding wire core. The simulation of this firework effect agrees well with experimental data, assuming submicron size and a temperature approaching boiling for the expanded microparticles cylinder.

Solid or hollow: which core cultivation method is the most effective at reducing nutrient loss with runoff from turf?

USDA-ARS?s Scientific Manuscript database

Excess nutrients in surfaces waters can result in undesirable consequences. Experiments were designed to quantify phosphorus and nitrogen transport with runoff from plots maintained as a golf course fairway to identify which cultural practice, solid tine or hollow tine core cultivation, will maximiz...

KSC-2011-4983

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians guide NASA's Juno spacecraft onto a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4974

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians prepare an overhead crane to move NASA's Juno spacecraft to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4972

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians will prepare NASA's Juno spacecraft for its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4958

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla., -- Workers transport NASA's Juno spacecraft from Astrotech's Payload Processing Facility in Titusville, Fla., to the Hazardous Processing Facility for fueling. The spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4985

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians secure NASA's Juno spacecraft to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4986

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., NASA's Juno spacecraft is secured to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4973

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians prepare an overhead crane to move NASA's Juno spacecraft to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4956

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla., -- Workers transport NASA's Juno spacecraft from Astrotech's Payload Processing Facility in Titusville, Fla., to the Hazardous Processing Facility for fueling. The spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4961

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians prepare NASA's Juno spacecraft for its move to a fueling stand. The spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4984

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians secure NASA's Juno spacecraft to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4954

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- Workers prepare to transport NASA's Juno spacecraft from Astrotech's Payload Processing Facility in Titusville, Fla., to the Hazardous Processing Facility for fueling. The spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4957

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla., -- Workers transport NASA's Juno spacecraft from Astrotech's Payload Processing Facility in Titusville, Fla., to the Hazardous Processing Facility for fueling. The spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4962

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians prepare the fueling stand for NASA's Juno spacecraft where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4955

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla., -- Workers transport NASA's Juno spacecraft from Astrotech's Payload Processing Facility in Titusville, Fla., to the Hazardous Processing Facility for fueling. The spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4981

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians using an overhead crane lower NASA's Juno spacecraft to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4982

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians using an overhead crane lower NASA's Juno spacecraft to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4979

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians using an overhead crane move NASA's Juno spacecraft to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4980

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians using an overhead crane lower NASA's Juno spacecraft to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

Some Aspects of an Air-Core Single-Coil Magnetic Suspension System

NASA Technical Reports Server (NTRS)

Hamlet, Irvin L.; Kilgore, Robert A.

1966-01-01

This paper presents some of the technical aspects in the development at the Langley Research Center of an air-cove, dual-wound, single-coil, magnetic-suspension system with one-dimensional control. Overall electrical system design features and techniques are discussed in addition to the problems of control and stability. Special treatment is given to the operation of a dual-wound, high-current support coil which provides the bias fields and superimposed modulated field. Other designs features include a six-phase, solid-state power stage for modulation of the relatively large magnitude control current, and an associated six-phase trigger circuit.

Implications for the melting phase relations in the MgO-FeO system at Core-Mantle Boundary conditions

NASA Astrophysics Data System (ADS)

Deng, J.; Lee, K. K. M.

2017-12-01

At nearly 2900 km depth, the core-mantle boundary (CMB) represents the largest density increase within the Earth going from a rocky mantle into an iron-alloy core. This compositional change sets up steep temperature gradients, which in turn influences mantle flow, structure and seismic velocities. Here we compute the melting phase relations of (Mg,Fe)O ferropericlase, the second most abundant mineral in the Earth's mantle, at CMB conditions and find that ultralow-velocity zones (ULVZs) could be explained by solid ferropericlase with 35 < Mg# = 100×(Mg/(Mg+Fe) by mol%) < 65. For compositions outside of this range, a solid ferropericlase cannot explain ULVZs. Additionally, solid ferropericlase can also provide a matrix for iron infiltration at the CMB by morphological instability, providing a mechanism for a high electrical conductivity layer of appropriate length scale inferred from core nutations.

A metallicity recipe for rocky planets

NASA Astrophysics Data System (ADS)

Dawson, Rebekah I.; Chiang, Eugene; Lee, Eve J.

2015-10-01

Planets with sizes between those of Earth and Neptune divide into two populations: purely rocky bodies whose atmospheres contribute negligibly to their sizes, and larger gas-enveloped planets possessing voluminous and optically thick atmospheres. We show that whether a planet forms rocky or gas-enveloped depends on the solid surface density of its parent disc. Assembly times for rocky cores are sensitive to disc solid surface density. Lower surface densities spawn smaller planetary embryos; to assemble a core of given mass, smaller embryos require more mergers between bodies farther apart and therefore exponentially longer formation times. Gas accretion simulations yield a rule of thumb that a rocky core must be at least 2M⊕ before it can acquire a volumetrically significant atmosphere from its parent nebula. In discs of low solid surface density, cores of such mass appear only after the gas disc has dissipated, and so remain purely rocky. Higher surface density discs breed massive cores more quickly, within the gas disc lifetime, and so produce gas-enveloped planets. We test model predictions against observations, using planet radius as an observational proxy for gas-to-rock content and host star metallicity as a proxy for disc solid surface density. Theory can explain the observation that metal-rich stars host predominantly gas-enveloped planets.

Adaptive control method for core power control in TRIGA Mark II reactor

NASA Astrophysics Data System (ADS)

Sabri Minhat, Mohd; Selamat, Hazlina; Subha, Nurul Adilla Mohd

2018-01-01

The 1MWth Reactor TRIGA PUSPATI (RTP) Mark II type has undergone more than 35 years of operation. The existing core power control uses feedback control algorithm (FCA). It is challenging to keep the core power stable at the desired value within acceptable error bands to meet the safety demand of RTP due to the sensitivity of nuclear research reactor operation. Currently, the system is not satisfied with power tracking performance and can be improved. Therefore, a new design core power control is very important to improve the current performance in tracking and regulate reactor power by control the movement of control rods. In this paper, the adaptive controller and focus on Model Reference Adaptive Control (MRAC) and Self-Tuning Control (STC) were applied to the control of the core power. The model for core power control was based on mathematical models of the reactor core, adaptive controller model, and control rods selection programming. The mathematical models of the reactor core were based on point kinetics model, thermal hydraulic models, and reactivity models. The adaptive control model was presented using Lyapunov method to ensure stable close loop system and STC Generalised Minimum Variance (GMV) Controller was not necessary to know the exact plant transfer function in designing the core power control. The performance between proposed adaptive control and FCA will be compared via computer simulation and analysed the simulation results manifest the effectiveness and the good performance of the proposed control method for core power control.

Atmospheric Mining in the Outer Solar System: Resource Capturing, Storage, and Utilization

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2012-01-01

Atmospheric mining in the outer solar system has been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as Helium 3 (3He) and hydrogen can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and hydrogen (deuterium, etc.) were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses were undertaken to investigate resource capturing aspects of atmospheric mining in the outer solar system. This included the gas capturing rate for hydrogen helium 4 and helium 3, storage options, and different methods of direct use of the captured gases. Additional supporting analyses were conducted to illuminate vehicle sizing and orbital transportation issues.

Photonic crystal fiber technology for high-performance all-fiber monolithic ultrafast fiber amplifiers

NASA Astrophysics Data System (ADS)

Papior, Sidsel R.; Weirich, Johannes; Johansen, Mette M.; Jakobsen, Christian; Michieletto, Mattia; Triches, Marco; Kristensen, Torben; Olesen, Anders S.; Petersen, Christian; Andersen, Thomas V.; Maack, Martin D.; Alkeskjold, Thomas T.

2018-02-01

Photonic crystal fiber (PCF) technology for ultrafast fiber amplifiers traditionally uses air holes as key elements for large mode area (LMA) fiber designs. These air holes are crucial for the performance of high-end LMA PCFs, but makes splicing and interfacing more complex. To reduce this complexity in mid-range amplifiers, we present single-mode polarization-maintaining Yb-doped LMA PCFs without air holes for easier splicing into monolithic all-fiber amplifier designs. A 30 μm core all-solid spliceable PCF is presented, and amplification of 1064 nm light above 50 W with an optical to optical efficiency of 80 % is demonstrated. Furthermore, to demonstrate the excellent reliability of PCF based monolithic amplifiers, we demonstrate ultra-longterm performance data of > 35 khrs on a 14 μm core step-index type PCF amplifier with low long-term power degradation slope of < 1.5 % / 10,000 h.

Building Aerodynamic Databases for the SLS Design Process

NASA Technical Reports Server (NTRS)

Rogers, Stuart; Dalle, Derek J.; Lee, Henry; Meeroff, Jamie; Onufer, Jeffrey; Chan, William; Pulliam, Thomas

2017-01-01

NASA's new Space Launch System (SLS) will be the first rocket since the Saturn V (1967-1973) to carry astronauts beyond low earth orbit-and will carry 10% more payload than Saturn V and three times the payload of the space shuttle. The SLS configuration consists of a center core and two solid rocket boosters that separate from the core as their fuel is exhausted two minutes after lift-off. During these first two minutes of flight, the vehicle powers its way through strong shock waves as it accelerates past the speed of sound, then pushes beyond strong aerodynamic loads at the maximum dynamic pressure, and is ultimately enveloped by gaseous plumes from the booster-separation motors. The SLS program relies on computational fluid dynamic (CFD) simulations to provide much of the data needed to build aerodynamic databases describing the structural load distribution, surface pressures, and aerodynamic forces on the vehicle.

On-chip supercapacitors with ultrahigh volumetric performance based on electrochemically co-deposited CuO/polypyrrole nanosheet arrays

NASA Astrophysics Data System (ADS)

Qian, Tao; Zhou, Jinqiu; Xu, Na; Yang, Tingzhou; Shen, Xiaowei; Liu, Xuejun; Wu, Shishan; Yan, Chenglin

2015-10-01

We introduce a new method for fabricating unique on-chip supercapacitors based on CuO/polypyrrole core/shell nanosheet arrays by means of direct electrochemical co-deposition on interdigital-like electrodes. The prepared all-solid-state device demonstrates exceptionally high specific capacitance of 1275.5 F cm-3 (˜40 times larger than that of CuO-only supercapacitors) and high-energy-density of 28.35 mWh cm-3, which are both significantly greater than other solid-state supercapacitors. More importantly, the device maintains approximately 100% capacity retention at 2.5 A cm-3 after 3000 cycles. The in situ co-deposition of CuO/polypyrrole nanosheets on interdigital substrate enables effective charge transport, electrode fabrication integrity, and device integration. Because of their high energy, power density, and stable cycling stability, these newly developed on-chip supercapacitors permit fast, reliable applications in portable and miniaturized electronic devices.

Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma

NASA Astrophysics Data System (ADS)

McCarthy, K. J.; Tamura, N.; Combs, S. K.; Panadero, N.; Ascabíbar, E.; Estrada, T.; García, R.; Hernández Sánchez, J.; López Fraguas, A.; Navarro, M.; Pastor, I.; Soleto, A.; TJ-II Team

2017-10-01

A cryogenic pellet injector (PI) and tracer encapsulated solid pellet (TESPEL) injector system has been operated in combination on the stellarator TJ-II. This unique arrangement has been created by piggy-backing a TESPEL injector onto the backend of a pipe-gun-type PI. The combined injector provides a powerful new tool for comparing ablation and penetration of polystyrene TESPEL pellets and solid hydrogen pellets, as well as for contrasting subsequent pellet particle deposition and plasma perturbation under analogous plasma conditions. For instance, a significantly larger increase in plasma line-averaged electron density, and electron content, is observed after a TESPEL pellet injection compared with an equivalent cryogenic pellet injection. Moreover, for these injections from the low-magnetic-field side of the plasma cross-section, TESPEL pellets deposit electrons deeper into the plasma core than cryogenic pellets. Finally, the physics behind these observations and possible implications for pellet injection studies are discussed.

Subdiffusive exciton transport in quantum dot solids.

PubMed

Akselrod, Gleb M; Prins, Ferry; Poulikakos, Lisa V; Lee, Elizabeth M Y; Weidman, Mark C; Mork, A Jolene; Willard, Adam P; Bulović, Vladimir; Tisdale, William A

2014-06-11

Colloidal quantum dots (QDs) are promising materials for use in solar cells, light-emitting diodes, lasers, and photodetectors, but the mechanism and length of exciton transport in QD materials is not well understood. We use time-resolved optical microscopy to spatially visualize exciton transport in CdSe/ZnCdS core/shell QD assemblies. We find that the exciton diffusion length, which exceeds 30 nm in some cases, can be tuned by adjusting the inorganic shell thickness and organic ligand length, offering a powerful strategy for controlling exciton movement. Moreover, we show experimentally and through kinetic Monte Carlo simulations that exciton diffusion in QD solids does not occur by a random-walk process; instead, energetic disorder within the inhomogeneously broadened ensemble causes the exciton diffusivity to decrease over time. These findings reveal new insights into exciton dynamics in disordered systems and demonstrate the flexibility of QD materials for photonic and optoelectronic applications.

On-chip supercapacitors with ultrahigh volumetric performance based on electrochemically co-deposited CuO/polypyrrole nanosheet arrays.

PubMed

Qian, Tao; Zhou, Jinqiu; Xu, Na; Yang, Tingzhou; Shen, Xiaowei; Liu, Xuejun; Wu, Shishan; Yan, Chenglin

2015-10-23

We introduce a new method for fabricating unique on-chip supercapacitors based on CuO/polypyrrole core/shell nanosheet arrays by means of direct electrochemical co-deposition on interdigital-like electrodes. The prepared all-solid-state device demonstrates exceptionally high specific capacitance of 1275.5 F cm(-3) (∼40 times larger than that of CuO-only supercapacitors) and high-energy-density of 28.35 mWh cm(-3), which are both significantly greater than other solid-state supercapacitors. More importantly, the device maintains approximately 100% capacity retention at 2.5 A cm(-3) after 3000 cycles. The in situ co-deposition of CuO/polypyrrole nanosheets on interdigital substrate enables effective charge transport, electrode fabrication integrity, and device integration. Because of their high energy, power density, and stable cycling stability, these newly developed on-chip supercapacitors permit fast, reliable applications in portable and miniaturized electronic devices.

The effects of the solid inner core and nonhydrostatic structure on the earth's forced nutations and earth tides

NASA Technical Reports Server (NTRS)

De Vries, Dan; Wahr, John M.

1991-01-01

This paper computes the effects of the solid inner core (IC) on the forced nutations and earth tides, and on certain of the earth's rotational normal modes. The theoretical results are extended to include the effects of a solid IC and of nonhydrostatic structure. The presence of the IC is responsible for a new, almost diurnal, prograde normal mode which involves a relative rotation between the IC and fluid outer core about an equatorial axis. It is shown that the small size of the IC's effects on both nutations and tides is a consequence of the fact that the IC's moments of inertia are less than 1/1000 of the entire earth's.

Stopping power beyond the adiabatic approximation

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

Caro, M.; Correa, A. A.; Artacho, E.

2017-06-01

Energetic ions traveling in solids deposit energy in a variety of ways, being nuclear and electronic stopping the two avenues in which dissipation is usually treated. This separation between electrons and ions relies on the adiabatic approximation in which ions interact via forces derived from the instantaneous electronic ground state. In a more detailed view, in which non-adiabatic effects are explicitly considered, electronic excitations alter the atomic bonding, which translates into changes in the interatomic forces. In this work, we use time dependent density functional theory and forces derived from the equations of Ehrenfest dynamics that depend instantaneously on themore » time-dependent electronic density. With them we analyze how the inter-ionic forces are affected by electronic excitations in a model of a Ni projectile interacting with a Ni target, a metallic system with strong electronic stopping and shallow core level states. We find that the electronic excitations induce substantial modifications to the inter-ionic forces, which translate into nuclear stopping power well above the adiabatic prediction. Particularly, we observe that most of the alteration of the adiabatic potential in early times comes from the ionization of the core levels of the target ions, not readily screened by the valence electrons.« less

Progress in high duty cycle, highly efficient fiber coupled 940-nm pump modules for high-energy class solid-state lasers

NASA Astrophysics Data System (ADS)

Platz, R.; Frevert, C.; Eppich, B.; Rieprich, J.; Ginolas, A.; Kreutzmann, S.; Knigge, S.; Erbert, G.; Crump, P.

2018-03-01

Diode lasers pump sources for future high-energy-class laser systems based on Yb-doped solid state amplifiers must deliver high optical intensities, high conversion efficiency (ηE = > 50%) at high repetition rates (f = 100 Hz) and long pulse widths (τ = 0.5…2 ms). Over the last decade, a series of pump modules has been developed at the Ferdinand-BraunInstitut to address these needs. The latest modules use novel wide-aperture single emitter diode lasers in passively side cooled stacks, operate at τ = 1 ms, f = 100…200 Hz and deliver 5…6 kW optical output power from a fiber with 1.9 mm core diameter and NA of 0.22, for spatial brightness BΩ > 1 MW/cm2 sr. The performance to date and latest developments in these high brightness modules are summarized here with recent work focusing on extending operation to other pumping conditions, as needed for alternative solid state laser designs. Specifically, the electro-optic, spectral and beam propagation characteristics of the module and its components are studied as a function of τ for a fixed duty cycle DC = 10% for τ = 1...100 ms, and first data is shown for continuous wave operation. Clear potential is seen to fulfill more demanding specifications without design changes. For example, high power long-pulse operation is demonstrated, with a power of > 5 kW at τ = 100 ms. Higher brightness operation is also confirmed at DC = 10% and τ = 1 ms, with > 5 kW delivered in a beam with BΩ > 4 MW/cm2 sr.

Printable Solid-State Lithium-Ion Batteries: A New Route toward Shape-Conformable Power Sources with Aesthetic Versatility for Flexible Electronics.

PubMed

Kim, Se-Hee; Choi, Keun-Ho; Cho, Sung-Ju; Choi, Sinho; Park, Soojin; Lee, Sang-Young

2015-08-12

Forthcoming flexible/wearable electronic devices with shape diversity and mobile usability garner a great deal of attention as an innovative technology to bring unprecedented changes in our daily lives. From the power source point of view, conventional rechargeable batteries (one representative example is a lithium-ion battery) with fixed shapes and sizes have intrinsic limitations in fulfilling design/performance requirements for the flexible/wearable electronics. Here, as a facile and efficient strategy to address this formidable challenge, we demonstrate a new class of printable solid-state batteries (referred to as "PRISS batteries"). Through simple stencil printing process (followed by ultraviolet (UV) cross-linking), solid-state composite electrolyte (SCE) layer and SCE matrix-embedded electrodes are consecutively printed on arbitrary objects of complex geometries, eventually leading to fully integrated, multilayer-structured PRISS batteries with various form factors far beyond those achievable by conventional battery technologies. Tuning rheological properties of SCE paste and electrode slurry toward thixotropic fluid characteristics, along with well-tailored core elements including UV-cured triacrylate polymer and high boiling point electrolyte, is a key-enabling technology for the realization of PRISS batteries. This process/material uniqueness allows us to remove extra processing steps (related to solvent drying and liquid-electrolyte injection) and also conventional microporous separator membranes, thereupon enabling the seamless integration of shape-conformable PRISS batteries (including letters-shaped ones) into complex-shaped objects. Electrochemical behavior of PRISS batteries is elucidated via an in-depth analysis of cell impedance, which provides a theoretical basis to enable sustainable improvement of cell performance. We envision that PRISS batteries hold great promise as a reliable and scalable platform technology to open a new concept of cell architecture and fabrication route toward flexible power sources with exceptional shape conformability and aesthetic versatility.

Assembly of flexible CoMoO4@NiMoO4·xH2O and Fe2O3 electrodes for solid-state asymmetric supercapacitors

PubMed Central

Wang, Jing; Zhang, Leipeng; Liu, Xusong; Zhang, Xiang; Tian, Yanlong; Liu, Xiaoxu; Zhao, Jiupeng; Li, Yao

2017-01-01

In this work, CoMoO4@NiMoO4·xH2O core-shell heterostructure electrode is directly grown on carbon fabric (CF) via a feasible hydrothermal procedure with CoMoO4 nanowires (NWs) as the core and NiMoO4 nanosheets (NSs) as the shell. This core-shell heterostructure could provide fast ion and electron transfer, a large number of active sites, and good strain accommodation. As a result, the CoMoO4@NiMoO4·xH2O electrode yields high-capacitance performance with a high specific capacitance of 1582 F g−1, good cycling stability with the capacitance retention of 97.1% after 3000 cycles and good rate capability. The electrode also shows excellent mechanical flexibility. Also, a flexible Fe2O3 nanorods/CF electrode with enhanced electrochemical performance was prepared. A solid-state asymmetric supercapacitor device is successfully fabricated by using flexible CoMoO4@NiMoO4·xH2O as the positive electrode and Fe2O3 as the negative electrode. The asymmetric supercapacitor with a maximum voltage of 1.6 V demonstrates high specific energy (41.8 Wh kg−1 at 700 W kg−1), high power density (12000 W kg−1 at 26.7 Wh kg−1), and excellent cycle ability with the capacitance retention of 89.3% after 5000 cycles (at the current density of 3A g−1). PMID:28106170

Three-Dimensional Hierarchical Structure ZnO@C@NiO on Carbon Cloth for Asymmetric Supercapacitor with Enhanced Cycle Stability.

PubMed

Ouyang, Yu; Xia, Xifeng; Ye, Haitao; Wang, Liang; Jiao, Xinyan; Lei, Wu; Hao, Qingli

2018-01-31

In this work, we synthesized the hierarchical ZnO@C@NiO core-shell nanorods arrays (CSNAs) grown on a carbon cloth (CC) conductive substrate by a three-step method involving hydrothermal and chemical bath methods. The morphology and chemical structure of the hybrid nanoarrays were characterized in detail. The combination and formation mechanism was proposed. The conducting carbon layer between ZnO and NiO layers can efficiently enhance the electric conductivity of the integrated electrodes, and also protect the corrosion of ZnO in an alkaline solution. Compared with ZnO@NiO nanorods arrays (NAs), the NiO in CC/ZnO@C@NiO electrodes, which possess a unique multilevel core-shell nanostructure exhibits a higher specific capacity (677 C/g at 1.43 A/g) and an enhanced cycling stability (capacity remain 71% after 5000 cycles), on account of the protection of carbon layer derived from glucose. Additionally, a flexible all-solid-state supercapacitor is readily constructed by coating the PVA/KOH gel electrolyte between the ZnO@C@NiO CSNAs and commercial graphene. The energy density of this all-solid-state device decreases from 35.7 to 16.0 Wh/kg as the power density increases from 380.9 to 2704.2 W/kg with an excellent cycling stability (87.5% of the initial capacitance after 10000 cycles). Thereby, the CC/ ZnO@C@NiO CSNAs of three-dimensional hierarchical structure is promising electrode materials for flexible all-solid-state supercapacitors.

The nuclear battery

NASA Astrophysics Data System (ADS)

Kozier, K. S.; Rosinger, H. E.

The evolution and present status of an Atomic Energy of Canada Limited program to develop a small, solid-state, passively cooled reactor power supply known as the Nuclear Battery is reviewed. Key technical features of the Nuclear Battery reactor core include a heat-pipe primary heat transport system, graphite neutron moderator, low-enriched uranium TRISO coated-particle fuel and the use of burnable poisons for long-term reactivity control. An external secondary heat transport system extracts useful heat energy, which may be converted into electricity in an organic Rankine cycle engine or used to produce high-pressure steam. The present reference design is capable of producing about 2400 kW(t) (about 600 kW(e) net) for 15 full-power years. Technical and safety features are described along with recent progress in component hardware development programs and market assessment work.

Validation of Core Temperature Estimation Algorithm

DTIC Science & Technology

2016-01-29

plot of observed versus estimated core temperature with the line of identity (dashed) and the least squares regression line (solid) and line equation...estimated PSI with the line of identity (dashed) and the least squares regression line (solid) and line equation in the top left corner. (b) Bland...for comparison. The root mean squared error (RMSE) was also computed, as given by Equation 2.

Reaction growth of MF2/a-C (M = Ca, Mg) core/shell nanowires at the interface of vapor and solid reactants.

PubMed

Huang, Chih-Hao; Chang, Yu-Hsu; Lee, Chi-Young; Chiu, Hsin-Tien

2006-01-03

C(6)F(6) vapor is employed to react with CaC(2) and Mg(3)N(2) to grow CaF(2)/a-C and Mg(2)F(2)/a-C core/shell nanowires (tens of micrometers in length, tens to hundreds of nanometers in wire diameter, and tens of nanometers in core diameter), respectively, in high yields. The growth mechanism is proposed to proceed via a reaction at the interface of the vapor and solid reactants.

Modified Reference SPS with Solid State Transmitting Antenna

NASA Technical Reports Server (NTRS)

Woodcock, G. R.; Sperber, B. R.

1980-01-01

The development of solid state microwave power amplifiers for a solar power satellite transmitting antenna is discussed. State-of-the-art power-added efficiency, gain, and single device power of various microwave solid state devices are compared. The GaAs field effect transistors and the Si-bipolar transistors appear potentially feasible for solar power satellite use. The integration of solid state devices into antenna array elements is examined and issues concerning antenna integration and consequent satellite configurations are examined.

Constraints on Mercury's Core-Mantle Boundary Region

NASA Astrophysics Data System (ADS)

Hauck, S. A., II; Chabot, N. L.; Sun, P.; Jing, Z.; Johnson, C. L.; Margot, J. L.; Padovan, S.; Peale, S. J.; Phillips, R. J.; Solomon, S. C.

2014-12-01

Understanding the boundary between a planet's metallic core and silicate mantle is important for constraining processes that dominate on either side of this boundary. Geophysical measurements of the planet Mercury by the MESSENGER spacecraft have provided evidence of a core larger than earlier, less-constrained estimates. Further, these results, taken in concert with measurements of the elemental composition of the surface by MESSENGER, have led to the suggestion that the uppermost layer of the outer core may be highly enriched in sulfur, and the top of the core may consist of a solid sulfide layer. The low iron and relatively large sulfur contents of the surface indicate highly reducing conditions during planet formation, placing constraints on the potential composition of Mercury's core. Recent metal-silicate partitioning experiments have developed new limits on the amount of sulfur and silicon that may partition into the core as a function of sulfur abundance at the surface. Models for the planet's internal structure constrained by the current best estimates of the bulk density, normalized polar moment of inertia, and fraction of the polar moment of inertia of the solid layer that extends from the surface to the top of the liquid outer core provide an important view of the layering and bulk composition of Mercury. By combining the results of these internal structure models with the experimental relationship between core and mantle composition we place new limits on core composition and structure. Further, imposing measured compositional constraints on the miscibility of iron-sulfur-silicon alloys yields important limits on the presence or absence of an immiscible sulfur-rich liquid layer or a solid sulfide layer at the top of the core.

Structure modeling and manufacturing PCFs for the range of 2-25 μm

NASA Astrophysics Data System (ADS)

Lvov, Alexandr; Salimgareev, Dmitrii; Korsakov, Michail; Korsakov, Alexandr; Zhukova, Liya

2017-11-01

Photostable and flexible materials transparent at the wide spectral range are necessary for the development of optical fiber units. Solid solutions of silver and monadic thallium halides are the most suitable crystal media for this purpose. The goal of our research was the search of optimum structure for the fibers with a single mode operation and a rather large core diameter. We modelled fiber structures (solid-core, hollow-core, active-core PCF) with various ratio of inserts diameters and increments between the inserts, basing on two crystal systems: AgCl-AgBr and AgBr-TlI. Then we chose the single mode fiber structure and manufactured it by means of extrusion.

Room temperature photoluminescence in the visible range from silicon nanowires grown by a solid-state reaction

NASA Astrophysics Data System (ADS)

Anguita, J. V.; Sharma, P.; Henley, S. J.; Silva, S. R. P.

2009-11-01

The solid-liquid-solid method (also known as the solid-state method) is used to produce silicon nanowires at the core of silica nanowires with a support catalyst layer structure of nickel and titanium layers sputtered on oxide-coated silicon wafers. This silane-free process is low cost and large-area compatible. Using electron microscopy and Raman spectroscopy we deduce that the wires have crystalline silicon cores. The nanowires show photoluminescence in the visible range (orange), and we investigate the origin of this band. We further show that the nanowires form a random mesh that acts as an efficient optical trap, giving rise to an optically absorbing medium.

Fuel inspection and reconstitution experience at Surry Power Station

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

Brookmire, T.A.

Surry Power Station, located on the James River near Williamsburg, Virginia, has two Westinghouse pressurized water reactors. Unit 2 consistently sets a high standard of fuel performance (no indication of fuel failures in recent cycles), while unit 1, since cycle 6, has been plagued with numerous fuel failures. Both Surry units operate with Westinghouse standard 15 x 15 fuel. Virginia Power management set goals to reduce the coolant activity, thus reducing person-rem exposure and the associated costs of high coolant activity. To achieve this goal, extensive fuel examination campaigns were undertaken that included high-magnification video inspectionsa, debris cleaning, wet andmore » vacuum fuel sipping, fuel rod ultrasonic testing, and eddy current examination. In the summer of 1985, during cycle 8 operation, Kraftwerk Union reconstituted (repaired) the damage, once-burned assemblies from cycles 6 and 7 by replacing failed fuel rods with solid Zircaloy-4 rods. Currently, cycle 9 has operated for 5 months without any indication of fuel failure (the cycle 9 core has two reconstituted assemblies).« less

Broad area quantum cascade lasers operating in pulsed mode above 100 °C λ ∼4.7 μm

NASA Astrophysics Data System (ADS)

Zhao, Yue; Yan, Fangliang; Zhang, Jinchuan; Liu, Fengqi; Zhuo, Ning; Liu, Junqi; Wang, Lijun; Wang, Zhanguo

2017-07-01

We demonstrate a broad area (400 μm) high power quantum cascade laser (QCL). A total peak power of 62 W operating at room temperature is achieved at λ ∼4.7 μm. The temperature dependence of the peak power characteristic is given in the experiment, and also the temperature of the active zone is simulated by a finite-element-method (FEM). We find that the interface roughness of the active core has a great effect on the temperature of the active zone and can be enormously improved using the solid source molecular beam epitaxy (MBE) growth system. Project supported by the National Basic Research Program of China (No. 2013CB632801), the National Key Research and Development Program (No. 2016YFB0402303), the National Natural Science Foundation of China (Nos. 61435014, 61627822, 61574136, 61306058, 61404131), the Key Projects of Chinese Academy of Sciences (No. ZDRW-XH-20164), and the Beijing Natural Science Foundation (No. 4162060).

A Solid-State Fibriform Supercapacitor Boosted by Host-Guest Hybridization between the Carbon Nanotube Scaffold and MXene Nanosheets.

PubMed

Yu, Chenyang; Gong, Yujiao; Chen, Ruyi; Zhang, Mingyi; Zhou, Jinyuan; An, Jianing; Lv, Fan; Guo, Shaojun; Sun, Gengzhi

2018-06-25

Fiber-shaped supercapacitors with improved specific capacitance and high rate capability are a promising candidate as power supply for smart textiles. However, the synergistic interaction between conductive filaments and active nanomaterials remains a crucial challenge, especially when hydrothermal or electrochemical deposition is used to produce a core (fiber)-shell (active materials) fibrous structure. On the other hand, although 2D pseudocapacitive materials, e.g., Ti 3 C 2 T x (MXene), have demonstrated high volumetric capacitance, high electrical conductivity, and hydrophilic characteristics, MXene-based electrodes normally suffer from poor rate capability owing to the sheet restacking especially when the loading level is high and solid-state gel is used as electrolyte. Herein, by hosting MXene nanosheets (Ti 3 C 2 T x ) in the corridor of a scrolled carbon nanotube (CNT) scaffold, a MXene/CNT fiber with helical structure is successfully fabricated. These features offer open spaces for rapid ion diffusion and guarantee fast electron transport. The solid-state supercapacitor based on such hybrid fibers with gel electrolyte coating exhibits a volumetric capacitance of 22.7 F cm -3 at 0.1 A cm -3 with capacitance retention of 84% at current density of 1.0 A cm -3 (19.1 F cm -3 ), improved volumetric energy density of 2.55 mWh cm -3 at the power density of 45.9 mW cm -3 , and excellent mechanical robustness. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analysis of Stainless Steel Sandwich Panels with a Metal Foam Core for Lightweight Fan Blade Design

NASA Technical Reports Server (NTRS)

Min, James B.; Ghosn, Louis J.; Lerch, Bradley A.; Raj, Sai V.; Holland, Frederic A., Jr.; Hebsur, Mohan G.

2004-01-01

The quest for cheap, low density and high performance materials in the design of aircraft and rotorcraft engine fan and propeller blades poses immense challenges to the materials and structural design engineers. The present study investigates the use of a sandwich foam fan blade mae up of solid face sheets and a metal foam core. The face sheets and the metal foam core material were an aerospace grade precipitation hardened 17-4 PH stainless steel with high strength and high toughness. The resulting structures possesses a high stiffness while being lighter than a similar solid construction. The material properties of 17-4 PH metal foam are reviewed briefly to describe the characteristics of sandwich structure for a fan blade application. A vibration analysis for natural frequencies and a detailed stress analysis on the 17-4 PH sandwich foam blade design for different combinations of kin thickness and core volume are presented with a comparison to a solid titanium blade.

Alfven seismic vibrations of crustal solid-state plasma in quaking paramagnetic neutron star

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

Bastrukov, S.; Xu, R.-X.; Molodtsova, I.

2010-11-15

Magneto-solid-mechanical model of two-component, core-crust, paramagnetic neutron star responding to quake-induced perturbation by differentially rotational, torsional, oscillations of crustal electron-nuclear solid-state plasma about axis of magnetic field frozen in the immobile paramagnetic core is developed. Particular attention is given to the node-free torsional crust-against-core vibrations under combined action of Lorentz magnetic and Hooke's elastic forces; the damping is attributed to Newtonian force of shear viscose stresses in crustal solid-state plasma. The spectral formulas for the frequency and lifetime of this toroidal mode are derived in analytic form and discussed in the context of quasiperiodic oscillations of the x-ray outburst fluxmore » from quaking magnetars. The application of obtained theoretical spectra to modal analysis of available data on frequencies of oscillating outburst emission suggests that detected variability is the manifestation of crustal Alfven's seismic vibrations restored by Lorentz force of magnetic field stresses.« less

Composite Cores

NASA Technical Reports Server (NTRS)

1990-01-01

Spang & Company's new configuration of converter transformer cores is a composite of gapped and ungapped cores assembled together in concentric relationship. The net effect of the composite design is to combine the protection from saturation offered by the gapped core with the lower magnetizing requirement of the ungapped core. The uncut core functions under normal operating conditions and the cut core takes over during abnormal operation to prevent power surges and their potentially destructive effect on transistors. Principal customers are aerospace and defense manufacturers. Cores also have applicability in commercial products where precise power regulation is required, as in the power supplies for large mainframe computers.

Scalable waveguide design for three-level operation in Neodymium doped fiber laser

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

Pax, Paul H.; Khitrov, Victor V.; Drachenberg, Derrek R.

We have constructed a double clad neodymium doped fiber laser operating on the three-level 4F 3/2 → 4I 9/2 transition. The laser has produced 11.5 W at 925 nm with 55% slope efficiency when pumped at 808 nm, comparable to the best previous results for a double-clad fiber configuration on this transition. Higher power pumping with both 808 nm and 880 nm sources resulted in an output of 27 W, albeit at lower slope efficiency. In both cases, output power was limited by available pump, indicating the potential for further power scaling. To suppress the stronger four-level 4F 3/2 →more » 4I 11/2 transition we developed a waveguide that provides spectral filtering distributed along the length of the fiber, based on an all-solid micro-structured optical fiber design, with resonant inclusions creating a leakage path to the cladding. Furthermore, the waveguide supports large mode areas and provides strong suppression at selectable wavelength bands, thus easing the restrictions on core and cladding sizes that limited power scaling of previous approaches.« less

Scalable waveguide design for three-level operation in Neodymium doped fiber laser

DOE PAGES

Pax, Paul H.; Khitrov, Victor V.; Drachenberg, Derrek R.; ...

2016-12-12

We have constructed a double clad neodymium doped fiber laser operating on the three-level 4F 3/2 → 4I 9/2 transition. The laser has produced 11.5 W at 925 nm with 55% slope efficiency when pumped at 808 nm, comparable to the best previous results for a double-clad fiber configuration on this transition. Higher power pumping with both 808 nm and 880 nm sources resulted in an output of 27 W, albeit at lower slope efficiency. In both cases, output power was limited by available pump, indicating the potential for further power scaling. To suppress the stronger four-level 4F 3/2 →more » 4I 11/2 transition we developed a waveguide that provides spectral filtering distributed along the length of the fiber, based on an all-solid micro-structured optical fiber design, with resonant inclusions creating a leakage path to the cladding. Furthermore, the waveguide supports large mode areas and provides strong suppression at selectable wavelength bands, thus easing the restrictions on core and cladding sizes that limited power scaling of previous approaches.« less

Mercury's core evolution

NASA Astrophysics Data System (ADS)

Deproost, Marie-Hélène; Rivoldini, Attilio; Van Hoolst, Tim

2016-10-01

Remote sensing data of Mercury's surface by MESSENGER indicate that Mercury formed under reducing conditions. As a consequence, silicon is likely the main light element in the core together with a possible small fraction of sulfur. Compared to sulfur, which does almost not partition into solid iron at Mercury's core conditions and strongly decreases the melting temperature, silicon partitions almost equally well between solid and liquid iron and is not very effective at reducing the melting temperature of iron. Silicon as the major light element constituent instead of sulfur therefore implies a significantly higher core liquidus temperature and a decrease in the vigor of compositional convection generated by the release of light elements upon inner core formation.Due to the immiscibility in liquid Fe-Si-S at low pressure (below 15 GPa), the core might also not be homogeneous and consist of an inner S-poor Fe-Si core below a thinner Si-poor Fe-S layer. Here, we study the consequences of a silicon-rich core and the effect of the blanketing Fe-S layer on the thermal evolution of Mercury's core and on the generation of a magnetic field.

Construction of Core-Shell NiMoO4@Ni-Co-S Nanorods as Advanced Electrodes for High-Performance Asymmetric Supercapacitors.

PubMed

Chen, Chao; Yan, Dan; Luo, Xin; Gao, Wenjia; Huang, Guanjie; Han, Ziwu; Zeng, Yan; Zhu, Zhihong

2018-02-07

In this work, hierarchical core-shell NiMoO 4 @Ni-Co-S nanorods were first successfully grown on nickel foam by a facile two-step method to fabricate a bind-free electrode. The well-aligned electrode wrapped by Ni-Co-S nanosheets displays excellent nanostructural properties and outstanding electrochemical performance, owing to the synergistic effects of both nickel molybdenum oxides and nickel cobalt sulfides. The prepared core-shell nanorods in a three-electrode cell yielded a high specific capacitance of 2.27 F cm -2 (1892 F g -1 ) at a current density of 5 mA cm -2 and retained 91.7% of the specific capacitance even after 6000 cycles. Their electrochemical performance was further investigated for their use as positive electrode for asymmetric supercapacitors. Notably, the energy density of the asymmetric supercapacitor device reached 2.45 mWh cm -3 at a power density of 0.131 W cm -3 , and still retained a remarkable 80.3% of the specific capacitance after 3500 cycles. There is great potential for the electrode composed of the core-shell NiMoO 4 @Ni-Co-S nanorods for use in an all-solid-state asymmetric supercapacitor device.

KSC-2011-4964

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians prepare an overhead crane to lift the cover from NASA's Juno spacecraft before its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4952

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla., -- At the Astrotech Payload Processing Facility in Titusville, Fla., technicians stretch a protective cover over NASA's Juno spacecraft. Juno is being prepared for its move to the Hazardous Processing Facility for fueling. The spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4978

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians disconnect NASA's Juno spacecraft from its transport prior to its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4976

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians attach an overhead crane to NASA's Juno spacecraft for its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4963

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians prepare cable for an overhead crane to lift the cover from NASA's Juno spacecraft before its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4977

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians disconnect NASA's Juno spacecraft from its transport prior to its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4975

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians attach an overhead crane to NASA's Juno spacecraft for its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4953

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At the Astrotech Payload Processing Facility in Titusville, Fla., , technicians secure a protective cover over NASA's Juno spacecraft. Juno is being prepared for its move to the Hazardous Processing Facility for fueling. The spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4966

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians use an overhead crane to lift the cover from NASA's Juno spacecraft before its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4971

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians use an overhead crane to lift the cover from NASA's Juno spacecraft before its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4969

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians use an overhead crane to lift the cover from NASA's Juno spacecraft before its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4965

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians use an overhead crane to lift the cover from NASA's Juno spacecraft before its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4970

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians use an overhead crane to lift the cover from NASA's Juno spacecraft before its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4968

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians use an overhead crane to lift the cover from NASA's Juno spacecraft before its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

KSC-2011-4967

NASA Image and Video Library

2011-06-27

CAPE CANAVERAL, Fla. -- At Astrotech's Hazardous Processing Facility in Titusville, Fla., technicians use an overhead crane to lift the cover from NASA's Juno spacecraft before its move to a fueling stand where the spacecraft will be loaded with the propellant necessary for orbit maneuvers and the attitude control system. Juno is scheduled to launch aboard a United Launch Alliance Atlas V rocket from Cape Canaveral, Fla., Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Troy Cryder

DANSSino: a pilot version of the DANSS neutrino detector

NASA Astrophysics Data System (ADS)

Alekseev, I.; Belov, V.; Brudanin, V.; Danilov, M.; Egorov, V.; Filosofov, D.; Fomina, M.; Hons, Z.; Kobyakin, A.; Medvedev, D.; Mizuk, R.; Novikov, E.; Olshevsky, A.; Rozov, S.; Rumyantseva, N.; Rusinov, V.; Salamatin, A.; Shevchik, Ye.; Shirchenko, M.; Shitov, Yu.; Starostin, A.; Svirida, D.; Tarkovsky, E.; Tikhomirov, I.; Yakushev, E.; Zhitnikov, I.; Zinatulina, D.

2014-07-01

DANSSino is a reduced pilot version of a solid-state detector of reactor antineutrinos (to be created within the DANSS project and installed under the industrial 3 GWth reactor of the Kalinin Nuclear Power Plant—KNPP). Numerous tests performed at a distance of 11 m from the reactor core demonstrate operability of the chosen design and reveal the main sources of the background. In spite of its small size (20 × 20 × 100 cm3), the pilot detector turned out to be quite sensitive to reactor antineutrinos, detecting about 70 IBD events per day with the signal-to-background ratio about unity.

Multimode Brillouin spectrum in a long tapered birefringent photonic crystal fiber.

PubMed

Tchahame, Joël Cabrel; Beugnot, Jean-Charles; Kudlinski, Alexandre; Sylvestre, Thibaut

2015-09-15

We investigate the stimulated Brillouin scattering (SBS) in a long tapered birefringent solid-core photonic crystal fiber (PCF) and compare our results with a similar but untapered PCF. It is shown that the taper generates a broadband and multipeaked Brillouin spectrum, while significantly increasing the threshold power. Furthermore, we observe that the strong fiber birefringence gives rise to a frequency shift of the Brillouin spectrum which increases along the fiber. Numerical simulations are also presented to account for the taper effect and the birefringence. Our findings open a new means to control or inhibit the SBS by tapering photonic crystal fibers.

Experimental study and thermodynamic modeling of the phase relation in the Fe-S-Si system with implications for the distribution of S and Si in a partially solidified core

NASA Astrophysics Data System (ADS)

Tao, R.; Fei, Y.

2017-12-01

Planetary cooling leads to solidification of any initially molten metallic core. Some terrestrial cores (e.g. Mercury) are formed and differentiated under relatively reduced conditions, and they are thought to be composed of Fe-S-Si. However, there are limited understanding of the phase relations in the Fe-S-Si system at high pressure and temperature. In this study, we conducted high-pressure experiments to investigate the phase relations in the Fe-S-Si system up to 25 GPa. Experimental results show that the liquidus and solidus in this study are slightly lower than those in the Fe-S binary system for the same S concentration in liquid at same pressure. The Fe3S, which is supposed to be the stable sub-solidus S-bearing phase in the Fe-S binary system above 17 GPa, is not observed in the Fe-S-Si system at 21 GPa. Almost all S prefers to partition into liquid, while the distribution of Si between solid and liquid depends on experimental P and T conditions. We obtained the partition coefficient log(KDSi) by fitting the experimental data as a function of P, T and S concentration in liquid. At a constant pressure, the log(KDSi) linearly decreases with 1/T(K). With increase of pressure, the slopes of linear correlation between log(KDSi) and 1/T(K) decreases, indicating that more Si partitions into solid at higher pressure. In order to interpolate and extrapolate the phase relations over a wide pressure and temperature range, we established a comprehensive thermodynamic model in the Fe-S-Si system. The results will be used to constrain the distribution of S and Si between solid inner core and liquid outer core for a range of planet sizes. A Si-rich solid inner core and a S-rich liquid outer core are suggested for an iron-rich core.

Investigation of mechanical properties and deformation behavior of single-crystal Al-Cu core-shell nanowire generated using non-equilibrium molecular dynamics simulation

NASA Astrophysics Data System (ADS)

Sarkar, Jit

2018-06-01

Molecular dynamics (MD) simulation studies were carried out to generate a cylindrical single-crystal Al-Cu core-shell nanowire and its mechanical properties like yield strength and Young's modulus were evaluated in comparison to a solid aluminum nanowire and hollow copper nanowire which combines to constitute the core-shell structure respectively. The deformation behavior due to changes in the number of Wigner-Seitz defects and dislocations during the entire tensile deformation process was thoroughly studied for the Al-Cu core-shell nanowire. The single-crystal Al-Cu core-shell nanowire shows much higher yield strength and Young's modulus in comparison to the solid aluminum core and hollow copper shell nanowire due to tangling of dislocations caused by lattice mismatch between aluminum and copper. Thus, the Al-Cu core-shell nanowire can be reinforced in different bulk matrix to develop new type of light-weight nanocomposite materials with greatly enhanced material properties.

Atmospheric Mining in the Outer Solar System: Outer Planet Orbital Transfer and Lander Analyses

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2016-01-01

Atmospheric mining in the outer solar system has been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as Helium 3 (3He) and deuterium can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and deuterium were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses were undertaken to investigate resource capturing aspects of atmospheric mining in the outer solar system. This included the gas capturing rate, storage options, and different methods of direct use of the captured gases. While capturing 3He, large amounts of hydrogen and 4He are produced. Analyses of orbital transfer vehicles (OTVs), landers, and the issues with in-situ resource utilization (ISRU) mining factories are included. Preliminary observations are presented on near-optimal selections of moon base orbital locations, OTV power levels, and OTV and lander rendezvous points. For analyses of round trip OTV flights from Uranus to Miranda or Titania, a 10-Megawatt electric (MWe) OTV power level and a 200-metric ton (MT) lander payload were selected based on a relative short OTV trip time and minimization of the number of lander flights. A similar optimum power level is suggested for OTVs flying from low orbit around Neptune to Thalassa or Triton. Several moon base sites at Uranus and Neptune and the OTV requirements to support them are also addressed.

Atmospheric Mining in the Outer Solar System: Outer Planet Orbital Transfer and Lander Analyses

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2016-01-01

Atmospheric mining in the outer solar system has been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as Helium 3 (3He) and deuterium can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and deuterium were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses were undertaken to investigate resource capturing aspects of atmospheric mining in the outer solar system. This included the gas capturing rate, storage options, and different methods of direct use of the captured gases. While capturing 3He, large amounts of hydrogen and 4He are produced. Analyses of orbital transfer vehicles (OTVs), landers, and the issues with in-situ resource utilization (ISRU) mining factories are included. Preliminary observations are presented on near-optimal selections of moon base orbital locations, OTV power levels, and OTV and lander rendezvous points. For analyses of round trip OTV flights from Uranus to Miranda or Titania, a 10- Megawatt electric (MWe) OTV power level and a 200 metricton (MT) lander payload were selected based on a relative short OTV trip time and minimization of the number of lander flights. A similar optimum power level is suggested for OTVs flying from low orbit around Neptune to Thalassa or Triton. Several moon base sites at Uranus and Neptune and the OTV requirements to support them are also addressed.

Special Purpose Nuclear Reactor (5 MW) for Reliable Power at Remote Sites Assessment Report

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

Sterbentz, James William; Werner, James Elmer; McKellar, Michael George

The Phenomena Identification and Ranking Table (PIRT) technique was conducted on the Special Purpose Reactor nuclear plant design. The PIRT is a structured process to identify safety-relevant/safety-significant phenomena and assess the importance and knowledge base by ranking the phenomena. The Special Purpose Reactor is currently in the conceptual design stage. The candidate reactor has a solid monolithic stainless steel core with an array of heat pipes and fuel pellets embedded in the monolith. The heat pipes are used to remove heat from the core using simple, reliable, and well-characterized physics (capillarity, boiling, and condensation). In the initial design, one heatmore » exchanger is used for the working fluid that produces energy, and a second heat exchanger is used to remove decay heat in emergency or shutdown conditions. In addition, a power conversion cycle such as an open-air Brayton system is available as an option for power conversion and process heat. This report summarizes and documents the process and scope of the four PIRT reviews, noting the major activities and conclusions. The identified phenomena, analyses, rationales, and associated ratings are presented along with a summary of the findings from the four individual PIRTs, namely (1) Reactor Accident and Normal Operations, (2) Heat Pipes, (3) Materials, and (4) Power Conversion. The PIRT reports for these four major system areas evaluated are attached as appendixes to this report and provide considerably more detail about each assessment as well as a more complete listing of the phenomena that were evaluated.« less

An interconnected network of core-forming melts produced by shear deformation

PubMed

Bruhn; Groebner; Kohlstedt

2000-02-24

The formation mechanism of terrestrial planetary cores is still poorly understood, and has been the subject of numerous experimental studies. Several mechanisms have been proposed by which metal--mainly iron with some nickel--could have been extracted from a silicate mantle to form the core. Most recent models involve gravitational sinking of molten metal or metal sulphide through a partially or fully molten mantle that is often referred to as a 'magma ocean'. Alternative models invoke percolation of molten metal along an interconnected network (that is, porous flow) through a solid silicate matrix. But experimental studies performed at high pressures have shown that, under hydrostatic conditions, these melts do not form an interconnected network, leading to the widespread assumption that formation of metallic cores requires a magma ocean. In contrast, here we present experiments which demonstrate that shear deformation to large strains can interconnect a significant fraction of initially isolated pockets of metal and metal sulphide melts in a solid matrix of polycrystalline olivine. Therefore, in a dynamic (non-hydrostatic) environment, percolation remains a viable mechanism for the segregation and migration of core-forming melts in a solid silicate mantle.

Integrated simulation of magnetic-field-assist fast ignition laser fusion

NASA Astrophysics Data System (ADS)

Johzaki, T.; Nagatomo, H.; Sunahara, A.; Sentoku, Y.; Sakagami, H.; Hata, M.; Taguchi, T.; Mima, K.; Kai, Y.; Ajimi, D.; Isoda, T.; Endo, T.; Yogo, A.; Arikawa, Y.; Fujioka, S.; Shiraga, H.; Azechi, H.

2017-01-01

To enhance the core heating efficiency in fast ignition laser fusion, the concept of relativistic electron beam guiding by external magnetic fields was evaluated by integrated simulations for FIREX class targets. For the cone-attached shell target case, the core heating performance deteriorates by applying magnetic fields since the core is considerably deformed and most of the fast electrons are reflected due to the magnetic mirror formed through the implosion. On the other hand, in the case of a cone-attached solid ball target, the implosion is more stable under the kilo-tesla-class magnetic field. In addition, feasible magnetic field configuration is formed through the implosion. As a result, the core heating efficiency doubles by magnetic guiding. The dependence of core heating properties on the heating pulse shot timing was also investigated for the solid ball target.

Initial Performance Results on IBM POWER6

NASA Technical Reports Server (NTRS)

Saini, Subbash; Talcott, Dale; Jespersen, Dennis; Djomehri, Jahed; Jin, Haoqiang; Mehrotra, Piysuh

2008-01-01

The POWER5+ processor has a faster memory bus than that of the previous generation POWER5 processor (533 MHz vs. 400 MHz), but the measured per-core memory bandwidth of the latter is better than that of the former (5.7 GB/s vs. 4.3 GB/s). The reason for this is that in the POWER5+, the two cores on the chip share the L2 cache, L3 cache and memory bus. The memory controller is also on the chip and is shared by the two cores. This serializes the path to memory. For consistently good performance on a wide range of applications, the performance of the processor, the memory subsystem, and the interconnects (both latency and bandwidth) should be balanced. Recognizing this, IBM has designed the Power6 processor so as to avoid the bottlenecks due to the L2 cache, memory controller and buffer chips of the POWER5+. Unlike the POWER5+, each core in the POWER6 has its own L2 cache (4 MB - double that of the Power5+), memory controller and buffer chips. Each core in the POWER6 runs at 4.7 GHz instead of 1.9 GHz in POWER5+. In this paper, we evaluate the performance of a dual-core Power6 based IBM p6-570 system, and we compare its performance with that of a dual-core Power5+ based IBM p575+ system. In this evaluation, we have used the High- Performance Computing Challenge (HPCC) benchmarks, NAS Parallel Benchmarks (NPB), and four real-world applications--three from computational fluid dynamics and one from climate modeling.

Chemical Convention in the Lunar Core from Melting Experiments on the Ironsulfur System

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

Li, J.; Liu, J.; Chen, B.

2012-03-26

By reanalyzing Apollo lunar seismograms using array-processing methods, a recent study suggests that the Moon has a solid inner core and a fluid outer core, much like the Earth. The volume fraction of the lunar inner core is 38%, compared with 4% for the Earth. The pressure at the Moon's core-mantle boundary is 4.8 GPa, and that at the ICB is 5.2 GPa. The partially molten state of the lunar core provides constraints on the thermal and chemical states of the Moon: The temperature at the inner core boundary (ICB) corresponds to the liquidus of the outer core composition, andmore » the mass fraction of the solid core allows us to infer the bulk composition of the core from an estimated thermal profile. Moreover, knowledge on the extent of core solidification can be used to evaluate the role of chemical convection in the origin of early lunar core dynamo. Sulfur is considered an antifreeze component in the lunar core. Here we investigate the melting behavior of the Fe-S system at the pressure conditions of the lunar core, using the multi-anvil apparatus and synchrotron and laboratory-based analytical methods. Our goal is to understand compositionally driven convection in the lunar core and assess its role in generating an internal magnetic field in the early history of the Moon.« less

Transparent SiO2-Ag core-satellite nanoparticle assembled layer for plasmonic-based chemical sensors

NASA Astrophysics Data System (ADS)

Chen, Tsung-Han; Jean, Ren-Der; Chiu, Kuo-Chuang; Chen, Chun-Hua; Liu, Dean-Mo

2012-05-01

We discovered a promising sensing capability of SiO2@Ag core-satellite nanoparticles with respect to organic melamine when they were consolidated into a solid-type thin-film entity. A series of theoretical models were proposed which provided calculation outcomes superior to those of existing models for the localized surface plasmon resonance spectra of the solid-state assemblies. We envisioned not only that such a SiO2@Ag film is a potential candidate for a transparent solid-state optical nanosensor for the detection of organic molecules but also that the resulting plasmonic resonance model facilitates a better understanding of such a solid-state nanosensor used for a number of sensory applications.

Solid-State Powered X-band Accelerator

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

Othman, Mohamed A.K.; Nann, Emilio A.; Dolgashev, Valery A.

2017-03-06

In this report we disseminate the hot test results of an X-band 100-W solid state amplifier chain for linear accelerator (linac) applications. Solid state power amplifiers have become increasingly attractive solutions for achieving high power in radar and maritime applications. Here the performance of solid state amplifiers when driving an RF cavity is investigated. Commercially available, matched and fully-packaged GaN on SiC HEMTs are utilized, comprising a wideband driver stage and two power stages. The amplifier chain has a high poweradded- efficiency and is able to supply up to ~1.2 MV/m field gradient at 9.2 GHz in a simple testmore » cavity, with a peak power exceeding 100 W. These findings set forth the enabling technology for solid-state powered linacs.« less

SLS Test Stand Site Selection

NASA Technical Reports Server (NTRS)

Crowe, Kathryn; Williams, Michael

2015-01-01

Test site selection is a critical element of the design, development and production of a new system. With the advent of the new Space Launch System (SLS), the National Aeronautics and Space Administration (NASA) had a number of test site selection decisions that needed to be made early enough in the Program to support the planned Launch Readiness Date (LRD). This case study focuses on decisions that needed to be made in 2011 and 2012 in preparation for the April 2013 DPMC decision about where to execute the Main Propulsion Test that is commonly referred to as "Green Run." Those decisions relied upon cooperative analysis between the Program, the Test Lab and Center Operations. The SLS is a human spaceflight vehicle designed to carry a crew farther into space than humans have previously flown. The vehicle consists of four parts: the crew capsule, the upper stage, the core stage, and the first stage solid rocket boosters. The crew capsule carries the astronauts, while the upper stage, the core stage, and solid rocket boosters provide thrust for the vehicle. In other words, the stages provide the "lift" part of the lift vehicle. In conjunction with the solid rocket boosters, the core stage provides the initial "get-off-the-ground" thrust to the vehicle. The ignition of the four core stage engines and two solid rocket boosters is the first step in the launch portion of the mission. The solid rocket boosters burn out after about 2 minutes of flight, and are then jettisoned. The core stage provides thrust until the vehicle reaches a specific altitude and speed, at which point the core stage is shut off and jettisoned, and the upper stage provides vehicle thrust for subsequent mission trajectories. The integrated core stage primarily consists of a liquid oxygen tank, a liquid hydrogen tank, and the four core stage engines. For the SLS program, four RS-25 engines were selected as the four core stage engines. The RS-25 engine is the same engine that was used for Space Shuttle. The test plan for the integrated core stage was broken down into several segments: Component testing, system level testing, and element level testing. In this context, components are items such as valves, controllers, sensors, etc. Systems are items such as an entire engine, a tank, or the outer stage body. The core stage itself is considered to be an element. The rocket engines are also considered an element. At the program level, it was decided to perform a single green run test on the integrated core stage prior to shipment of it to Kennedy Space Center (KSC) for use in the EM-1 test flight of the SLS vehicle. A green run test is the first live fire of the new integrated core stage and engine elements - without boosters of course. The SLS Program had to decide where to perform SLS green run testing.

Interior of Mars from spacecraft and complementary data.

NASA Astrophysics Data System (ADS)

Dehant, Veronique

2015-04-01

Mars, as Earth, Venus and Mercury is a terrestrial planet having, in addition to the mantle and lithosphere, a core composed of an iron alloy. This core might be completely liquid, completely solid or may contain a solid part (the inner core) and a liquid part. The existence of a magnetic field around a planet is mainly explained by the presence of motions in the liquid part in the core. The absence of a magnetic field does not help in constraining the state of the core as it might be completely solid or completely liquid but the motion (convection) might not be sufficient to maintain it, or even contain a growing inner core inside a liquid core composed of iron or Nickel and a percentage of light element corresponding to the eutectic composition (no precipitation). The planet Mars is smaller than Earth. It has evolved differently. We know for the Earth that the core is liquid and that the inner core is forming by precipitation of iron. For Mars spacecraft observation of the gravity field and its time variation allow us to obtain the effect of mass repartition, and in particular those induced by the solid tides. These tidal deformation of the planet are larger for a planet with a liquid core than for a completely solid planet. Recent spacecraft orbiting around Mars (MGS, Mars Odyssey, MRO, Mars Express) have allowed to obtain the k2 tidal Love numbers. This measurement is rather at the limit of what the observation can tell us but seems to indicate that Mars has a liquid core. The absence of a present-day global magnetic field places Mars in the situation where the inner core is not yet forming or has reached the eutectic. Physical observation of the planet other than tides also allow us to obtain information about the interior of Mars: its rotation and orientation changes. Planetary rotation can be separated into the rotation speed around an axis and the orientation of this axis (or another axis of the planet) in space. Most of us know that the rotation of a boiled egg noticeably differs from that of a raw egg. This simple observation shows that information on the inside of an object can be obtained from its rotation. The same idea applies to the rotation of celestial bodies. Their rotation changes and orientation changes provide information on the interior. For Mars, as for the Earth, it is mainly the changes in the orientation that are important to characterize their interiors, the length-of-day variations being mostly related to atmospheric angular moment transfer to the solid planet. The orientation changes are called precession, the long-term change, and nutation, the periodic wiggly short-term changes that are the most interesting to obtain information about the core. Nutations have up to now only been unambiguously observed for the Earth, but the InSIGHT (Interior exploration using Seismic Investigations, Geodesy, and Heat Transport) NASA mission to be launched in 2016, will carry out an X-band transponder enabling us to do Doppler measurements on the motion of Mars with respect to Earth, and therewith to determine the nutations and the interior structure of Mars.

NASA Marches on with Test of RS-25 Engine for New Space Launch System

NASA Image and Video Library

2016-07-29

NASA engineers conducted a successful developmental test of RS-25 rocket engine No. 0528 July 29, 2016, to collect critical performance data for the most powerful rocket in the world – the Space Launch System (SLS). The engine roared to life for a full 650-second test on the A-1 Test Stand at NASA’s Stennis Space Center, near Bay St. Louis, Mississippi, marking another step forward in development of the SLS, which will launch humans deeper into space than ever before, including on the journey to Mars. Four RS-25 engines, joined with a pair of solid rocket boosters, will power the SLS core stage at launch. The RS-25 engines used on the first four SLS flights are former space shuttle main engines, modified to operate at a higher performance level and with a new engine controller, which allows communication between the vehicle and engine.

Implications of the Homogeneous Nucleation Barrier for Top-Down Crystallization in Mercury's Core

NASA Astrophysics Data System (ADS)

Huguet, L.; Hauck, S. A.; Van Orman, J. A.; Jing, Z.

2018-05-01

Crystallization of solids in planetary cores depends both on ambient temperatures falling below the liquidus and on the ability to nucleate crystal growth. We discuss the implications of the nucleation barrier for thermal evolution of Mercury's core.

Obseration of flow regime transition in CFB riser using an LDV

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

Yue, Paul C.; Mei, Joseph S.; Shadle, Lawrence J.

2011-01-01

The solids flow in a circulating fluidized bed (CFB) riser is often described to have a core-annular structure. For a given superficial gas velocity, at the initial introduction of solids into a riser a flow structure of dilute upflow regime exists. Continuing to increase the solids flow in the riser transitions the flow structure to the core-annular flow regime. However, with further increase of solids flow a condition is reached, depending on the superficial gas velocity, where all the solids across the riser cross section flow upwards, even those at the wall. When the solids flux, solids fraction and gasmore » velocity are relatively high, such a condition is described as the dense phase suspense upflow (DSU) regime. In this paper we report our observations of these flow regime transitions by using a laser Doppler velocimeter (LDV) to monitor the upward and downward particle flow velocities at and near the riser wall of the National Energy Technology Laboratory’s 30.4 centimeters diameter CFB cold flow model. The particles were high density polyethylene (PPE) spheres with a Sauter mean diameter of 861 micron and a density of 800 kg/m3. Three superficial gas velocities of 6.55 m/s, 10.67 m/s and 13.72 m/s were used in this study. For the case of superficial gas velocity 6.55 m/s, the experimental data show that the transition from dilute upflow to core-annular flow occurred when the solids flux was about 7 kg/m{sup 2}-s and the transition from core-annular flow to dense suspension upflow was about 147 kg/m{sup 2}-s. As the superficial gas velocity was increased to 10.67 m/s the corresponding flow regime transitions were at 34 kg/m{sup 2}-s and 205 kg/m{sup 2}-s, respectively. For the case of superficial gas velocity of 13.72 m/s the data showed no distinct transition of flow regimes. The particles were all upflow for the range of solids fluxes from 10 kg/m{sup 2}-s to 286 kg/m{sup 2}-s.« less

Simulation of the planetary interior differentiation processes in the laboratory.

PubMed

Fei, Yingwei

2013-11-15

A planetary interior is under high-pressure and high-temperature conditions and it has a layered structure. There are two important processes that led to that layered structure, (1) percolation of liquid metal in a solid silicate matrix by planet differentiation, and (2) inner core crystallization by subsequent planet cooling. We conduct high-pressure and high-temperature experiments to simulate both processes in the laboratory. Formation of percolative planetary core depends on the efficiency of melt percolation, which is controlled by the dihedral (wetting) angle. The percolation simulation includes heating the sample at high pressure to a target temperature at which iron-sulfur alloy is molten while the silicate remains solid, and then determining the true dihedral angle to evaluate the style of liquid migration in a crystalline matrix by 3D visualization. The 3D volume rendering is achieved by slicing the recovered sample with a focused ion beam (FIB) and taking SEM image of each slice with a FIB/SEM crossbeam instrument. The second set of experiments is designed to understand the inner core crystallization and element distribution between the liquid outer core and solid inner core by determining the melting temperature and element partitioning at high pressure. The melting experiments are conducted in the multi-anvil apparatus up to 27 GPa and extended to higher pressure in the diamond-anvil cell with laser-heating. We have developed techniques to recover small heated samples by precision FIB milling and obtain high-resolution images of the laser-heated spot that show melting texture at high pressure. By analyzing the chemical compositions of the coexisting liquid and solid phases, we precisely determine the liquidus curve, providing necessary data to understand the inner core crystallization process.

Simulation of the Planetary Interior Differentiation Processes in the Laboratory

PubMed Central

Fei, Yingwei

2013-01-01

A planetary interior is under high-pressure and high-temperature conditions and it has a layered structure. There are two important processes that led to that layered structure, (1) percolation of liquid metal in a solid silicate matrix by planet differentiation, and (2) inner core crystallization by subsequent planet cooling. We conduct high-pressure and high-temperature experiments to simulate both processes in the laboratory. Formation of percolative planetary core depends on the efficiency of melt percolation, which is controlled by the dihedral (wetting) angle. The percolation simulation includes heating the sample at high pressure to a target temperature at which iron-sulfur alloy is molten while the silicate remains solid, and then determining the true dihedral angle to evaluate the style of liquid migration in a crystalline matrix by 3D visualization. The 3D volume rendering is achieved by slicing the recovered sample with a focused ion beam (FIB) and taking SEM image of each slice with a FIB/SEM crossbeam instrument. The second set of experiments is designed to understand the inner core crystallization and element distribution between the liquid outer core and solid inner core by determining the melting temperature and element partitioning at high pressure. The melting experiments are conducted in the multi-anvil apparatus up to 27 GPa and extended to higher pressure in the diamond-anvil cell with laser-heating. We have developed techniques to recover small heated samples by precision FIB milling and obtain high-resolution images of the laser-heated spot that show melting texture at high pressure. By analyzing the chemical compositions of the coexisting liquid and solid phases, we precisely determine the liquidus curve, providing necessary data to understand the inner core crystallization process. PMID:24326245

High-pressure melting experiments on Fe-Si alloys and implications for silicon as a light element in the core

NASA Astrophysics Data System (ADS)

Ozawa, Haruka; Hirose, Kei; Yonemitsu, Kyoko; Ohishi, Yasuo

2016-12-01

We carried out melting experiments on Fe-Si alloys to 127 GPa in a laser-heated diamond-anvil cell (DAC). On the basis of textural and chemical characterizations of samples recovered from a DAC, a change in eutectic liquid composition in the Fe-FeSi binary system was examined with increasing pressure. The chemical compositions of coexisting liquid and solid phases were quantitatively determined with field-emission-type electron microprobes. The results demonstrate that silicon content in the eutectic liquid decreases with increasing pressure to less than 1.5 ± 0.1 wt.% Si at 127 GPa. If silicon is a single light element in the core, 4.5 to 12 wt.% Si is required in the outer core in order to account for its density deficit from pure iron. However, such a liquid core, whose composition is on the Si-rich side of the eutectic point, crystallizes less dense solid, CsCl (B2)-type phase at the inner core boundary (ICB). Our data also show that the difference in silicon concentration between coexisting solid and liquid is too small to account for the observed density contrast across the ICB. These indicate that silicon cannot be the sole light element in the core. Previous geochemical and cosmochemical arguments, however, strongly require ∼6 wt.% Si in the core. It is possible that the Earth's core originally included ∼6 wt.% Si but then became depleted in silicon by crystallizing SiO2 or MgSiO3.

Compact atmospheric pressure plasma self-resonant drive circuits

NASA Astrophysics Data System (ADS)

Law, V. J.; Anghel, S. D.

2012-02-01

This paper reports on compact solid-state self-resonant drive circuits that are specifically designed to drive an atmospheric pressure plasma jet and a parallel-plate dielectric barrier discharge of small volume (0.5 cm3). The atmospheric pressure plasma (APP) device can be operated with helium, argon or a mixture of both. Equivalent electrical models of the self-resonant drive circuits and discharge are developed and used to estimate the plasma impedance, plasma power density, current density or electron number density of three APP devices. These parameters and the kinetic gas temperature are dependent on the self-resonant frequency of the APP device. For a fixed switching frequency and APP device geometry, the plasma parameters are controlled by adjusting the dc voltage at the primary coil and the gas flow rate. The resonant frequency is controlled by the selection of the switching power transistor and means of step-up voltage transformation (ferrite core, flyback transformer, or Tesla coil). The flyback transformer operates in the tens of kHz, the ferrite core in the hundreds of kHz and Tesla coil in the MHz range. Embedded within this work is the principle of frequency pulling which is exemplified in the flyback transformer circuit that utilizes a pickup coil for feedback control of the switching frequency.

Atmospheric Mining in the Outer Solar System: Aerial Vehicle Mission and Design Issues

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2015-01-01

Atmospheric mining in the outer solar system has been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as Helium 3 (3He) and deuterium can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and deuterium were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses were undertaken to investigate resource capturing aspects of atmospheric mining in the outer solar system. This included the gas capturing rate, storage options, and different methods of direct use of the captured gases. While capturing 3He, large amounts of hydrogen and 4He are produced. With these two additional gases, the potential for fueling small and large fleets of additional exploration and exploitation vehicles exists. The mining aerospacecraft (ASC) could fly through the outer planet atmospheres, for global weather observations, localized storm or other disturbance investigations, wind speed measurements, polar observations, etc. Analyses of orbital transfer vehicles (OTVs), landers, and in-situ resource utilization (ISRU) mining factories are included. Preliminary observations are presented on near-optimal selections of moon base orbital locations, OTV power levels, and OTV and lander rendezvous points.

Observations on the Chernobyl Disaster and LNT

PubMed Central

Jaworowski, Zbigniew

2010-01-01

The Chernobyl accident was probably the worst possible catastrophe of a nuclear power station. It was the only such catastrophe since the advent of nuclear power 55 years ago. It resulted in a total meltdown of the reactor core, a vast emission of radionuclides, and early deaths of only 31 persons. Its enormous political, economic, social and psychological impact was mainly due to deeply rooted fear of radiation induced by the linear non-threshold hypothesis (LNT) assumption. It was a historic event that provided invaluable lessons for nuclear industry and risk philosophy. One of them is demonstration that counted per electricity units produced, early Chernobyl fatalities amounted to 0.86 death/GWe-year), and they were 47 times lower than from hydroelectric stations (∼40 deaths/GWe-year). The accident demonstrated that using the LNT assumption as a basis for protection measures and radiation dose limitations was counterproductive, and lead to sufferings and pauperization of millions of inhabitants of contaminated areas. The projections of thousands of late cancer deaths based on LNT, are in conflict with observations that in comparison with general population of Russia, a 15% to 30% deficit of solid cancer mortality was found among the Russian emergency workers, and a 5% deficit solid cancer incidence among the population of most contaminated areas. PMID:20585443

Observations on the Chernobyl Disaster and LNT.

PubMed

Jaworowski, Zbigniew

2010-01-28

The Chernobyl accident was probably the worst possible catastrophe of a nuclear power station. It was the only such catastrophe since the advent of nuclear power 55 years ago. It resulted in a total meltdown of the reactor core, a vast emission of radionuclides, and early deaths of only 31 persons. Its enormous political, economic, social and psychological impact was mainly due to deeply rooted fear of radiation induced by the linear non-threshold hypothesis (LNT) assumption. It was a historic event that provided invaluable lessons for nuclear industry and risk philosophy. One of them is demonstration that counted per electricity units produced, early Chernobyl fatalities amounted to 0.86 death/GWe-year), and they were 47 times lower than from hydroelectric stations ( approximately 40 deaths/GWe-year). The accident demonstrated that using the LNT assumption as a basis for protection measures and radiation dose limitations was counterproductive, and lead to sufferings and pauperization of millions of inhabitants of contaminated areas. The projections of thousands of late cancer deaths based on LNT, are in conflict with observations that in comparison with general population of Russia, a 15% to 30% deficit of solid cancer mortality was found among the Russian emergency workers, and a 5% deficit solid cancer incidence among the population of most contaminated areas.

Characterization of core–shell MOF particles by depth profiling experiments using on-line single particle mass spectrometry

DOE PAGES

Cahill, J. F.; Fei, H.; Cohen, S. M.; ...

2015-01-05

Materials with core-shell structures have distinct properties that lend themselves to a variety of potential applications. Characterization of small particle core-shell materials presents a unique analytical challenge. Herein, single particles of solid-state materials with core-shell structures were measured using on-line aerosol time-of-flight mass spectrometry (ATOFMS). Laser 'depth profiling' experiments verified the core-shell nature of two known core-shell particle configurations (< 2 mu m diameter) that possessed inverted, complimentary core-shell compositions (ZrO2@SiO2 versus SiO2@ZrO2). The average peak area ratios of Si and Zr ions were calculated to definitively show their core-shell composition. These ratio curves acted as a calibrant for anmore » uncharacterized sample - a metal-organic framework (MOF) material surround by silica (UiO-66(Zr)@SiO2; UiO = University of Oslo). ATOFMS depth profiling was used to show that these particles did indeed exhibit a core-shell architecture. The results presented here show that ATOFMS can provide unique insights into core-shell solid-state materials with particle diameters between 0.2-3 mu m.« less

Solar Power Satellite (SPS) solid-state antenna power combiner

NASA Technical Reports Server (NTRS)

1980-01-01

A low loss power-combining microstrip antenna suitable for solid state solar power satellite (SPS) application was developed. A unique approach for performing both the combining and radiating function in a single cavity-type circuit was verified, representing substantial refinements over previous demonstration models in terms of detailed geometry to obtain good matching and adequate bandwidth at the design frequency. The combiner circuit was designed, built, and tested and the overall results support the view that the solid state power-combining antenna approach is a viable candidate for a solid state SPS antenna building block.

NASA satellite communications application research. Phase 2: Efficient high power, solid state amplifier for EFH communications

NASA Technical Reports Server (NTRS)

Benet, James

1993-01-01

The final report describes the work performed from 9 Jun. 1992 to 31 Jul. 1993 on the NASA Satellite Communications Application Research (SCAR) Phase 2 program, Efficient High Power, Solid State Amplifier for EHF Communications. The purpose of the program was to demonstrate the feasibility of high-efficiency, high-power, EHF solid state amplifiers that are smaller, lighter, more efficient, and less costly than existing traveling wave tube (TWT) amplifiers by combining the output power from up to several hundred solid state amplifiers using a unique orthomode spatial power combiner (OSPC).

The high-pressure phase diagram of Fe(0.94)O - A possible constituent of the earth's core

NASA Technical Reports Server (NTRS)

Knittle, Elise; Jeanloz, Raymond

1991-01-01

Electrical resistivity measurements to pressures of 83 GPa and temperatures ranging from 300 K to 4300 K confirm the presence of both crystalline and liquid metallic phases of FeO at pressures above 60-70 GPa and temperatures above 1000 K. By experimentally determinig the melting temperature of FeO to 100 GPa and of a model-core composition at 83 GPa, it is found that the solid-melt equilibria can be described by complete solid solution across the Fe-FeO system at pressures above 70 GPa. The results indicate that oxygen is a viable and likely candidate for the major light alloying element of the earth's liquid outer core. The data suggest that the temperature at the core-mantle boundary is close to 4800 K and that heat lost out of the core accounts for more than 20 percent of the heat flux observed at the surface.

Serially connected solid oxide fuel cells having monolithic cores

DOEpatents

Herceg, Joseph E.

1987-01-01

A solid oxide fuel cell for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of cell segments electrically serially connected in the flow direction, each segment consisting of electrolyte walls and interconnect that are substantially devoid of any composite inert materials for support. Instead, the core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material therebetween. Means direct the fuel to the anode-exposed core passageways and means direct the oxidant to the cathode-exposed core passageways; and means also direct the galvanic output to an exterior circuit. Each layer of the electrolyte composite materials is of the order of 0.002-0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002-0.05 cm thick. Between 2 and 50 cell segments may be connected in series.

An Interconnected Network of Core-Forming Melts Produced by Shear Deformation

NASA Technical Reports Server (NTRS)

Bruhn, D.; Groebner, N.; Kohlstedt, D. L.

2000-01-01

The formation mechanism of terrestrial planetary is still poorly understood, and has been the subject of numerous experimental studies. Several mechanisms have been proposed by which metal-mainly iron with some nickel-could have been extracted from a silicate mantle to form the core. Most recent models involve gravitational sinking of molten metal or metal sulphide through a partially or fully molten mantle that is often referred to as a'magma ocean. Alternative models invoke percolation of molten metal along an interconnected network (that is, porous flow) through a solid silicate matrix. But experimental studies performed at high pressures have shown that, under hydrostatic conditions, these melts do not form an interconnected network, leading to the widespread assumption that formation of metallic cores requires a magma ocean. In contrast, here we present experiments which demonstrate that shear deformation to large strains can interconnect a significant fraction of initially isolated pockets of metal and metal sulphide melts in a solid matrix of polycrystalline olivine. Therefore, in a dynamic (nonhydrostatic) environment, percolation remains a viable mechanism for the segregation and migration of core-forming melts in a solid silicate mantle.

Electronic tunability of zero dispersion wavelengths in a spiral photonic crystal fiber for supercontinuum generation in the communication window

NASA Astrophysics Data System (ADS)

Hossain, Md. Nazmul; Alam, M. Shah; Mohsin, K. M.; Hasan, Dihan Md. Nuruddin

2011-08-01

A liquid crystal infiltrated spiral photonic crystal fiber (LCSPCF) is presented here for electrical tuning of two zero dispersion wavelengths (ZDWs) in the present communication window. The proposed LCSPCF shows tunability of the ZDWs from 1433 nm to 2136 nm due to the rotation of the infiltrated LC mesogen induced by the external electric field. Therefore, the ZDW can easily be shifted towards the available pump wavelength for effective supercontinuum generation (SCG) over a broad wavelength region. By tuning the bandwidth (BW) in between the two ZDWs the extension of the generated supercontinuum (SC) spectrum can also be electrically controlled. This will help the SCG in our desired band with optimum power budget. Moreover, the index guiding mechanism of the proposed soft glass LCSPCF shows improvement over the narrow operational bandwidth and the low nonlinearity of the band-gap guided silica LCPCF. Additionally, the solid core of the proposed LCSPCF is less lossy than the previously proposed liquid crystal core PCF.

X-ray emission from clusters of galaxies

NASA Technical Reports Server (NTRS)

Mushotzky, R. F.

1983-01-01

Some X-ray spectral observations of approximately 30 clusters of galaxies from HEAO-1 are summarized. There exists strong correlations between X-ray luminosity, L(x), and temperature kT in the form L(x)alphaT to the 2.3 power. This result combined with the L(x) central galaxy density relation and the virial theorem indicates that the core dadius of the gas should be roughly independent of L(x) or KT and that more luminous clusters have a greater fraction of their virial mass in gas. The poor correlation of KT and optical velocity dispersion seems to indicate that clusters have a variety of equations of state. There is poor agreement between X-ray imaging observations and optical and X-ray spectral measures of the polytropic index. Most clusters show Fe emission lines with a strong indication that they all have roughly 1/2 solar abundance. The evidence for cooling in the cores of several clusters is discussed based on spectral observations with the Einstein solid state spectrometer.

Blockage effects on the hydrodynamic performance of a marine cross-flow turbine.

PubMed

Consul, Claudio A; Willden, Richard H J; McIntosh, Simon C

2013-02-28

This paper explores the influence of blockage and free-surface deformation on the hydrodynamic performance of a generic marine cross-flow turbine. Flows through a three-bladed turbine with solidity 0.125 are simulated at field-test blade Reynolds numbers, O(10(5)-10(6)), for three different cross-stream blockages: 12.5, 25 and 50 per cent. Two representations of the free-surface boundary are considered: rigid lid and deformable free surface. Increasing the blockage is observed to lead to substantial increases in the power coefficient; the highest power coefficient computed is 1.23. Only small differences are observed between the two free-surface representations, with the deforming free-surface turbine out-performing the rigid lid turbine by 6.7 per cent in power at the highest blockage considered. This difference is attributed to the increase in effective blockage owing to the deformation of the free surface. Hydrodynamic efficiency, the ratio of useful power generated to overall power removed from the flow, is found to increase with blockage, which is consistent with the presence of a higher flow velocity through the core of the turbine at higher blockage ratios. Froude number is found to have little effect on thrust and power coefficients, but significant influence on surface elevation drop across the turbine.

Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma

DOE PAGES

McCarthy, K. J.; Tamura, N.; Combs, S. K.; ...

2018-01-05

Here, a cryogenic pellet injector (PI) and tracer encapsulated solid pellet (TESPEL) injector system has been operated in combination on the stellarator TJ-II. This unique arrangement has been created by piggy-backing a TESPEL injector onto the backend of a pipe-gun–type PI. The combined injector provides a powerful new tool for comparing ablation and penetration of polystyrene TESPEL pellets and solid hydrogen pellets, as well as for contrasting subsequent pellet particle deposition and plasma perturbation under analogous plasma conditions. For instance, a significantly larger increase in plasma line-averaged electron density, and electron content, is observed after a TESPEL pellet injection comparedmore » with an equivalent cryogenic pellet injection. Moreover, for these injections from the low-magnetic-field side of the plasma cross-section, TESPEL pellets deposit electrons deeper into the plasma core than cryogenic pellets. Finally, the physics behind these observations and possible implications for pellet injection studies are discussed.« less

Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma

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

McCarthy, K. J.; Tamura, N.; Combs, S. K.

Here, a cryogenic pellet injector (PI) and tracer encapsulated solid pellet (TESPEL) injector system has been operated in combination on the stellarator TJ-II. This unique arrangement has been created by piggy-backing a TESPEL injector onto the backend of a pipe-gun–type PI. The combined injector provides a powerful new tool for comparing ablation and penetration of polystyrene TESPEL pellets and solid hydrogen pellets, as well as for contrasting subsequent pellet particle deposition and plasma perturbation under analogous plasma conditions. For instance, a significantly larger increase in plasma line-averaged electron density, and electron content, is observed after a TESPEL pellet injection comparedmore » with an equivalent cryogenic pellet injection. Moreover, for these injections from the low-magnetic-field side of the plasma cross-section, TESPEL pellets deposit electrons deeper into the plasma core than cryogenic pellets. Finally, the physics behind these observations and possible implications for pellet injection studies are discussed.« less

Influence of power density on polymerization behavior and bond strengths of dual-cured resin direct core foundation systems.

PubMed

Oto, Tatsuki; Yasuda, Genta; Tsubota, Keishi; Kurokawa, Hiroyasu; Miyazaki, Masashi; Platt, Jeffrey A

2009-01-01

This study examined the influence of power density on dentin bond strength and polymerization behavior of dual-cured direct core foundation resin systems. Two commercially available dual-cured direct core foundation resin systems, Clearfil DC Core Automix with Clearfil DC Bond and UniFil Core with Self-Etching Bond, were studied. Bovine mandibular incisors were mounted in autopolymerizing resin and the facial dentin surfaces were ground wet on 600-grit SiC paper. Dentin surfaces were treated according to manufacturer's recommendations. The resin pastes were condensed into the mold and cured with the power densities of 0 (no irradiation), 100, 200, 400 and 600 mW/cm2. Ten specimens per group were stored in 37 degrees C water for 24 hours, then shear tested at a crosshead speed of 1.0 mm/minute in a universal testing machine. An ultrasonic measurement device was used to measure the ultrasonic velocities through the core foundation resins. The power densities selected were 0 (no irradiation), 200, and 600 mW/cm2, and ultrasonic velocity was calculated. ANOVA and Tukey HSD tests were performed at a level of 0.05. The highest bond strengths were obtained when the resin pastes were cured with the highest power density for both core foundation systems (16.8 +/- 1.9 MPa for Clearfil DC Core Automix, 15.6 +/- 2.9 MPa for UniFil Core). When polymerized with the power densities under 200 mW/cm2, significantly lower bond strengths were observed compared to those obtained with the power density of 600 mW/cm2. As the core foundation resins hardened, the sonic velocities increased and this tendency differed among the power density of the curing unit. When the sonic velocities at three minutes after the start of measurements were compared, there were no significant differences among different irradiation modes for UniFil Core, while a significant decrease in sonic velocity was obtained when the resin paste was chemically polymerized compared with dual-polymerization for Clearfil DC Core Automix. The data suggests that the dentin bond strengths and polymerization behavior of the dual-cured, direct core foundation systems are still affected by the power density of the curing unit. With a careful choice of the core foundation systems and power density of the curing unit, the benefit of using resin composites to endodontically-treated teeth might be acceptable.

Preliminary Electrochemical Characterization of Anode Supported Solid Oxide Cell (AS-SOC) Produced in the Institute of Power Engineering Operated in Electrolysis Mode (SOEC)

NASA Astrophysics Data System (ADS)

Kupecki, Jakub; Motyliński, Konrad; Skrzypkiewicz, Marek; Wierzbicki, Michał; Naumovich, Yevgeniy

2017-12-01

The article discusses the operation of solid oxide electrochemical cells (SOC) developed in the Institute of Power Engineering as prospective key components of power-to-gas systems. The fundamentals of the solid oxide cells operated as fuel cells (SOFC - solid oxide fuel cells) and electrolysers (SOEC - solid oxide fuel cells) are given. The experimental technique used for electrochemical characterization of cells is presented. The results obtained for planar cell with anodic support are given and discussed. Based on the results, the applicability of the cells in power-to-gas systems (P2G) is evaluated.

NEUTRONIC REACTOR SYSTEM

DOEpatents

Daniels, F.

1957-10-15

Gas-cooled solid-moderator type reactors wherein the fissionable fuel and moderator materials are each in the form of solid pebbles, or discrete particles, and are substantially homogeneously mixed in the proper proportion and placed within the core of the reactor are described. The shape of these discrete particles must be such that voids are present between them when mixed together. Helium enters the bottom of the core and passes through the voids between the fuel and moderator particles to absorb the heat generated by the chain reaction. The hot helium gas is drawn off the top of the core and may be passed through a heat exchanger to produce steam.

Two-Phase Dynamics Simulations of the Growth and Instability of Earth's Inner Core

NASA Astrophysics Data System (ADS)

Hernlund, J. W.; Jellinek, M.; Labrosse, S.

2008-12-01

When the center of Earth's core began to freeze from a homogeneous liquid 1-2 billion years ago, its constitution was very likely that of a mushy region. As this incipient inner core grew by further crystallization of the outer core, an increase in gravity force allowed for the solid grains to compress against one another, undergo viscous compaction, and begin to expel remnant fluid out of the inner core by percolation. Meanwhile, inside the inner core the residual fluid and solid remained in equilibrium, and any perturbations that resulted in upwelling of the deformable mush would also be accompanied by decompression melting. Upwelling and melting regions might then increase in liquid fraction, become less dense, and hence buoyant in a way that would propel them upward at a faster rate, setting up a runaway instability and partial Rayleigh-Taylor-like overturn of Earth's inner core. Structures inherited from this event possibly include the distinct innermost inner core posited by seismologists to exist at Earth's centermost 300-600 km. We use a new two-phase dynamics code to model this scenario in axi-symmetric geometry in order to understand whether and when such an instability occurred, what size the core will have been at the onset of instability, and the degree and style of deformation that would have accompanied this episode. We have found that the growth of instability competes with the rate of background melt percolation, such that the instability would only have occurred after the inner core reaches a critical size and expelled a certain amount of liquid from its interior. A linear stability analysis confirms that there is a critical Rayleigh number for the onset of instability at a given radius. The combined constraints show that the inner core is guaranteed to have undergone this kind of instability, at a time and strength governed solely by physical properties such as grain size, density differences between liquid and solid, and viscosities of the phases.

Solid oxide fuel cell having monolithic core

DOEpatents

Ackerman, J.P.; Young, J.E.

1983-10-12

A solid oxide fuel cell is described for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support. Instead, the core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material therebetween. The electrolyte walls are arranged and backfolded between adjacent interconnect walls operable to define a plurality of core passageways alternately arranged where the inside faces thereof have only the anode material or only the cathode material exposed. Means direct the fuel to the anode-exposed core passageways and means direct the oxidant to the anode-exposed core passageways and means direct the oxidant to the cathode-exposed core passageway; and means also direct the galvanic output to an exterior circuit. Each layer of the electrolyte and interconnect materials is of the order of 0.002 to 0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002 to 0.05 cm thick.

High Power Diode Laser-Treated HP-HVOF and Twin Wire Arc-Sprayed Coatings for Fossil Fuel Power Plants

NASA Astrophysics Data System (ADS)

Mann, B. S.

2013-08-01

This article deals with high power diode laser (HPDL) surface modification of twin wire arc-sprayed (TWAS) and high pressure high velocity oxy-fuel (HP-HVOF) coatings to combat solid particle erosion occurring in fossil fuel power plants. To overcome solid particle impact wear above 673 K, Cr3C2-NiCr-, Cr3C2-CoNiCrAlY-, and WC-CrC-Ni-based HVOF coatings are used. WC-CoCr-based HVOF coatings are generally used below 673 K. Twin wire arc (TWA) spraying of Tafa 140 MXC and SHS 7170 cored wires is used for a wide range of applications for a temperature up to 1073 K. Laser surface modification of high chromium stainless steels for steam valve components and LPST blades is carried out regularly. TWA spraying using SHS 7170 cored wire, HP-HVOF coating using WC-CoCr powder, Ti6Al4V alloy, and high chromium stainless steels (X20Cr13, AISI 410, X10CrNiMoV1222, 13Cr4Ni, 17Cr4Ni) were selected in the present study. Using robotically controlled parameters, HPDL surface treatments of TWAS-coated high strength X10CrNiMoV1222 stainless steel and HP-HVOF-coated AISI 410 stainless steel samples were carried out and these were compared with HPDL-treated high chromium stainless steels and titanium alloy for high energy particle impact wear (HEPIW) resistance. The HPDL surface treatment of the coatings has improved the HEPIW resistance manifold. The improvement in HPDL-treated stainless steels and titanium alloys is marginal and it is not comparable with that of HPDL-treated coatings. These coatings were also compared with "as-sprayed" coatings for fracture toughness, microhardness, microstructure, and phase analyses. The HEPIW resistance has a strong relationship with the product of fracture toughness and microhardness of the HPDL-treated HP-HVOF and TWAS SHS 7170 coatings. This development opens up a possibility of using HPDL surface treatments in specialized areas where the problem of HEPIW is very severe. The HEPIW resistance of HPDL-treated high chromium stainless steels and titanium alloys, HPDL-treated TWAS SHS 7170 and HP-HVOF coatings, and their micrographs and X-ray diffraction analysis is reported in this article.

Electrodeposited Nanolaminated CoNiFe Cores for Ultracompact DC-DC Power Conversion

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

Kim, J; Kim, M; Herrault, F

2015-09-01

Laminated metallic alloy cores (i.e., alternating layers of thin film metallic alloy and insulating material) of appropriate lamination thickness enable suppression of eddy current losses at high frequencies. Magnetic cores comprised of many such laminations yield substantial overall magnetic volume, thereby enabling high-power operation. Previously, we reported nanolaminated permalloy (Ni-80 Fe-20) cores based on a sequential electrodeposition technique, demonstrating negligible eddy current losses at peak flux densities up to 0.5 T and operating at megahertz frequencies. This paper demonstrates improved performance of nanolaminated cores comprising tens to hundreds of layers of 300-500-nm-thick CoNiFe films that exhibit superior magnetic properties (e.g.,more » higher saturation flux density and lower coercivity) than permalloy. Nanolaminated CoNiFe cores can be operated up to a peak flux density of 0.9 T, demonstrating improved power handling capacity and exhibiting 30% reduced volumetric core loss, attributed to lowered hysteresis losses compared to the nanolaminated permalloy core of the same geometry. Operating these cores in a buck dc-dc power converter at a switching frequency of 1 MHz, the nanolaminated CoNiFe cores achieved a conversion efficiency exceeding 90% at output power levels up to 7 W, compared to an achieved permalloy core conversion efficiency below 86% at 6 W.« less

Influence of a Fluid Lunar Core on the Moons Orientation

NASA Technical Reports Server (NTRS)

Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.; Yoder, C. F.; Dickey, J. O.

2001-01-01

Oblateness of and dissipation at the lunar liquid-core/solid-mantle boundary affects the precession of core and mantle. Analysis of Lunar Laser ranges gives a weak detection of oblateness and a strong determination of dissipation. Additional information is contained in the original extended abstract.

Registration of reactor neutrinos with the highly segmented plastic scintillator detector DANSSino

NASA Astrophysics Data System (ADS)

Belov, V.; Brudanin, V.; Danilov, M.; Egorov, V.; Fomina, M.; Kobyakin, A.; Rusinov, V.; Shirchenko, M.; Shitov, Yu; Starostin, A.; Zhitnikov, I.

2013-05-01

DANSSino is a simplified pilot version of a solid-state detector of reactor antineutrino (it is being created within the DANSS project and will be installed close to an industrial nuclear power reactor). Numerous tests performed under a 3 GWth reactor of the Kalinin NPP at a distance of 11 m from the core demonstrate operability of the chosen design and reveal the main sources of the background. In spite of its small size (20 × 20 × 100 cm3), the pilot detector turned out to be quite sensitive to reactor neutrinos, detecting about 70 IBD events per day with the signal-to-background ratio about unity.

Nuclear thermal propulsion test facility requirements and development strategy

NASA Technical Reports Server (NTRS)

Allen, George C.; Warren, John; Clark, J. S.

1991-01-01

The Nuclear Thermal Propulsion (NTP) subpanel of the Space Nuclear Propulsion Test Facilities Panel evaluated facility requirements and strategies for nuclear thermal propulsion systems development. High pressure, solid core concepts were considered as the baseline for the evaluation, with low pressure concepts an alternative. The work of the NTP subpanel revealed that a wealth of facilities already exists to support NTP development, and that only a few new facilities must be constructed. Some modifications to existing facilities will be required. Present funding emphasis should be on long-lead-time items for the major new ground test facility complex and on facilities supporting nuclear fuel development, hot hydrogen flow test facilities, and low power critical facilities.

A Dual Source Ion Trap Mass Spectrometer for the Mars Organic Molecule Analyzer of ExoMars 2018

NASA Technical Reports Server (NTRS)

Brickerhoff, William B.; vanAmerom, F. H. W.; Danell, R. M.; Arevalo, R.; Atanassova, M.; Hovmand, L.; Mahaffy, P. R.; Cotter, R. J.

2011-01-01

We present details on the objectives, requirements, design and operational approach of the core mass spectrometer of the Mars Organic Molecule Analyzer (MOMA) investigation on the 2018 ExoMars mission. The MOMA mass spectrometer enables the investigation to fulfill its objective of analyzing the chemical composition of organic compounds in solid samples obtained from the near surface of Mars. Two methods of ionization are realized, associated with different modes of MOMA operation, in a single compact ion trap mass spectrometer. The stringent mass and power constraints of the mission have led to features such as low voltage and low frequency RF operation [1] and pulse counting detection.

Sorption Equilibria of Vapor Phase Organic Pollutants on Unsaturated Soils and Soil Minerals

DTIC Science & Technology

1990-04-01

Sorbent Characterization .. ........ .......... 6 a. Description of Inorganic Solids and Soils. .... ........ 6 b. Moisture Content...compounds (TCE and toluene) is compared for a cored depth profile obtained from an unsaturated soil and for simulated profiles using inorganic solids. The...Sorbent Characterization a. Description of Inorganic Solids and Soils Inorganic solids were used for initial sorption studies to develop experimental

Phase equilibria of a low S and C lunar core: Implications for an early lunar dynamo and physical state of the current core

NASA Astrophysics Data System (ADS)

Righter, K.; Go, B. M.; Pando, K. A.; Danielson, L.; Ross, D. K.; Rahman, Z.; Keller, L. P.

2017-04-01

Multiple lines of geochemical and geophysical evidence suggest the Moon has a small metallic core, yet the composition of the core is poorly constrained. The physical state of the core (now or in the past) depends on detailed knowledge of its composition, and unfortunately, there is little available data on relevant multicomponent systems (i.e., Fe-Ni-S-C) at lunar interior conditions. In particular, there is a dearth of phase equilibrium data to elucidate whether a specific core composition could help to explain an early lunar geodynamo and magnetic field intensities, or current solid inner core/liquid outer core states. We utilize geochemical information to estimate the Ni, S and C contents of the lunar core, and then carry out phase equilibria experiments on several possible core compositions at the pressure and temperature conditions relevant to the lunar interior. The first composition is 0.5 wt% S and 0.375 wt% C, based on S and C contents of Apollo glasses. A second composition contains 1 wt% each of S and C, and assumes that the lunar mantle experienced degassing of up to 50% of its S and C. Finally a third composition contains C as the dominant light element. Phase equilibrium experiments were completed at 1, 3 and 5 GPa, using piston cylinder and multi-anvil techniques. The first composition has a liquidus near 1550 °C and solidus near 1250 °C. The second composition has a narrower liquidus and solidus temperatures of 1400 and 1270 °C, respectively, while the third composition is molten down to 1150 °C. As the composition crystallizes, the residual liquid becomes enriched in S and C, but S enrichment is greater due to the incorporation of C (but not S) into solid metallic FeNi. Comparison of these results to thermal models for the Moon allow an evaluation of which composition is consistent with the geophysical data of an early dynamo and a currently solid inner and liquid outer core. Composition 1 has a high enough liquidus to start crystallizing early in lunar history (4.3 Ga), consistent with the possible core dynamo initiated by crystallization of a solid inner core. Composition 1 also stays partially molten throughout lunar history, and could easily explain the seismic data. Composition 2, on the other hand, can satisfy one or the other set of geophysical data, but not both and thus seems like a poor candidate for a lunar core composition. Composition 3 remains molten to temperatures that are lower than current estimates for the lunar core, thus ruling out the possibility of a C-rich (and S-poor) lunar core. The S- and C-poor core composition studied here (composition 1) is consistent with all available geochemical and geophysical data and provides a simple heat source and mechanism for a lunar core dynamo (core crystallization) that would obviate the need for other primary mechanisms such as impacts, core-mantle coupling, or unusual thermal histories.

Earth's inner core nucleation paradox

NASA Astrophysics Data System (ADS)

Huguet, Ludovic; Van Orman, James A.; Hauck, Steven A.; Willard, Matthew A.

2018-04-01

The conventional view of Earth's inner core is that it began to crystallize at Earth's center when the temperature dropped below the melting point of the iron alloy and has grown steadily since that time as the core continued to cool. However, this model neglects the energy barrier to the formation of the first stable crystal nucleus, which is commonly represented in terms of the critical supercooling required to overcome the barrier. Using constraints from experiments, simulations, and theory, we show that spontaneous crystallization in a homogeneous liquid iron alloy at Earth's core pressures requires a critical supercooling of order 1000 K, which is too large to be a plausible mechanism for the origin of Earth's inner core. We consider mechanisms that can lower the nucleation barrier substantially. Each has caveats, yet the inner core exists: this is the nucleation paradox. Heterogeneous nucleation on a solid metallic substrate tends to have a low energy barrier and offers the most straightforward solution to the paradox, but solid metal would probably have to be delivered from the mantle and such events are unlikely to have been common. A delay in nucleation, whether due to a substantial nucleation energy barrier, or late introduction of a low energy substrate, would lead to an initial phase of rapid inner core growth from a supercooled state. Such rapid growth may lead to distinctive crystallization texturing that might be observable seismically. It would also generate a spike in chemical and thermal buoyancy that could affect the geomagnetic field significantly. Solid metal introduced to Earth's center before it reached saturation could also provide a nucleation substrate, if large enough to escape complete dissolution. Inner core growth, in this case, could begin earlier and start more slowly than standard thermal models predict.

Properties of iron under core conditions

NASA Astrophysics Data System (ADS)

Brown, J. M.

2003-04-01

Underlying an understanding of the geodynamo and evolution of the core is knowledge of the physical and chemical properties of iron and iron mixtures under high pressure and temperature conditions. Key properties include the viscosity of the fluid outer core, thermal diffusivity, equations-of-state, elastic properties of solid phases, and phase equilibria for iron and iron-dominated mixtures. As is expected for work that continues to tax technological and intellectual limits, controversy has followed both experimental and theoretical progress in this field. However, estimates for the melting temperature of the inner core show convergence and the equation-of-state for iron as determined in independent experiments and theories are in remarkable accord. Furthermore, although the structure and elastic properties of the solid inner-core phase remains uncertain, theoretical and experimental underpinnings are better understood and substantial progress is likely in the near future. This talk will focus on an identification of properties that are reasonably well known and those that merit further detailed study. In particular, both theoretical and experimental (static and shock wave) determinations of the density of iron under extreme conditions are in agreement at the 1% or better level. The behavior of the Gruneisen parameter (which determines the geothermal gradient and controls much of the outer core heat flux) is constrained by experiment and theory under core conditions for both solid and liquid phases. Recent experiments and theory are suggestive of structure or structures other than the high-pressure hexagonal close-packed (HCP) phase. Various theories and experiments for the elasticity of HCP iron remain in poor accord. Uncontroversial constraints on core chemistry will likely never be possible. However, reasonable bounds are possible on the basis of seismic profiles, geochemical arguments, and determinations of sound velocities and densities at high pressure and temperature.

Unraveling Core Functional Microbiota in Traditional Solid-State Fermentation by High-Throughput Amplicons and Metatranscriptomics Sequencing.

PubMed

Song, Zhewei; Du, Hai; Zhang, Yan; Xu, Yan

2017-01-01

Fermentation microbiota is specific microorganisms that generate different types of metabolites in many productions. In traditional solid-state fermentation, the structural composition and functional capacity of the core microbiota determine the quality and quantity of products. As a typical example of food fermentation, Chinese Maotai-flavor liquor production involves a complex of various microorganisms and a wide variety of metabolites. However, the microbial succession and functional shift of the core microbiota in this traditional food fermentation remain unclear. Here, high-throughput amplicons (16S rRNA gene amplicon sequencing and internal transcribed space amplicon sequencing) and metatranscriptomics sequencing technologies were combined to reveal the structure and function of the core microbiota in Chinese soy sauce aroma type liquor production. In addition, ultra-performance liquid chromatography and headspace-solid phase microextraction-gas chromatography-mass spectrometry were employed to provide qualitative and quantitative analysis of the major flavor metabolites. A total of 10 fungal and 11 bacterial genera were identified as the core microbiota. In addition, metatranscriptomic analysis revealed pyruvate metabolism in yeasts (genera Pichia, Schizosaccharomyces, Saccharomyces , and Zygosaccharomyces ) and lactic acid bacteria (genus Lactobacillus ) classified into two stages in the production of flavor components. Stage I involved high-level alcohol (ethanol) production, with the genus Schizosaccharomyces serving as the core functional microorganism. Stage II involved high-level acid (lactic acid and acetic acid) production, with the genus Lactobacillus serving as the core functional microorganism. The functional shift from the genus Schizosaccharomyces to the genus Lactobacillus drives flavor component conversion from alcohol (ethanol) to acid (lactic acid and acetic acid) in Chinese Maotai-flavor liquor production. Our findings provide insight into the effects of the core functional microbiota in soy sauce aroma type liquor production and the characteristics of the fermentation microbiota under different environmental conditions.

Processing of solid solution, mixed uranium/refractory metal carbides for advanced space nuclear power and propulsion systems

NASA Astrophysics Data System (ADS)

Knight, Travis Warren

Nuclear thermal propulsion (NTP) and space nuclear power are two enabling technologies for the manned exploration of space and the development of research outposts in space and on other planets such as Mars. Advanced carbide nuclear fuels have been proposed for application in space nuclear power and propulsion systems. This study examined the processing technologies and optimal parameters necessary to fabricate samples of single phase, solid solution, mixed uranium/refractory metal carbides. In particular, the pseudo-ternary carbide, UC-ZrC-NbC, system was examined with uranium metal mole fractions of 5% and 10% and corresponding uranium densities of 0.8 to 1.8 gU/cc. Efforts were directed to those methods that could produce simple geometry fuel elements or wafers such as those used to fabricate a Square Lattice Honeycomb (SLHC) fuel element and reactor core. Methods of cold uniaxial pressing, sintering by induction heating, and hot pressing by self-resistance heating were investigated. Solid solution, high density (low porosity) samples greater than 95% TD were processed by cold pressing at 150 MPa and sintering above 2600 K for times longer than 90 min. Some impurity oxide phases were noted in some samples attributed to residual gases in the furnace during processing. Also, some samples noted secondary phases of carbon and UC2 due to some hyperstoichiometric powder mixtures having carbon-to-metal ratios greater than one. In all, 33 mixed carbide samples were processed and analyzed with half bearing uranium as ternary carbides of UC-ZrC-NbC. Scanning electron microscopy, x-ray diffraction, and density measurements were used to characterize samples. Samples were processed from powders of the refractory mono-carbides and UC/UC 2 or from powders of uranium hydride (UH3), graphite, and refractory metal carbides to produce hypostoichiometric mixed carbides. Samples processed from the constituent carbide powders and sintered at temperatures above the melting point of UC showed signs of liquid phase sintering and were shown to be largely solid solutions. Pre-compaction of mixed carbide powders prior to sintering was shown to be necessary to achieve high densities. Hypostoichiometric, samples processed at 2500 K exhibited only the initial stage of sintering and solid solution formation. Based on these findings, a suggested processing methodology is proposed for producing high density, solid solution, mixed carbide fuels. Pseudo-binary, refractory carbide samples hot pressed at 3100 K and 6 MPa showed comparable densities (approximately 85% of the theoretical value) to samples processed by cold pressing and sintering at temperatures of 2800 K.

Tidal constraints on the interior of Venus

NASA Astrophysics Data System (ADS)

Dumoulin, Caroline; Tobie, Gabriel; Verhoeven, Olivier; Rosenblatt, Pascal; Rambaux, Nicolas

2017-04-01

As a prospective study for a future exploration of Venus, we compute the tidal response of Venus' interior assuming various mantle compositions and temperature profiles representative of different scenarios of Venus' formation and evolution. The mantle density and seismic velocities are modeled from thermodynamical equilibria of mantle minerals and used to predict the moment of inertia, Love numbers and tidal lag characterizing the signature of the internal structure in the gravity field. The viscoelasticity of the mantle is parameterized using an Andrade rheology. From the models considered here, the moment of inertia lies in the range of 0.327 to 0.342, corresponding to a core radius of 2900 to 3450 km. The potential Love number, k2, varies from 0.25 to 0.36. Viscoelasticity of the mantle strongly increases the Love number relative to previous elastic models : depending on mantle viscosity, k2 is increased by up to 25% using a liquid core. Moreover, once a viscoelastic rheology is assumed for the core, our calculations show that the estimation of k2 from tracking of Magellan and Pioneer Venus Orbiter does not rule out the possibility of a completely solid core. Except if the solid core has a high viscosity (≥ 1018 Pa.s), solutions with both liquid and solid cores are consistent with the present-day estimation of k2. More accurate estimation of the Love number together with estimation of tidal lag by future exploration mission are required to determine the state of Venus' core and to constrain the thermo-compositional evolution of the mantle.

High voltage DC switchgear development for multi-kW space power system: Aerospace technology development of three types of solid state power controllers for 200-1100VDC with current ratings of 25, 50, and 80 amperes with one type utilizing an electromechanical device

NASA Technical Reports Server (NTRS)

Billings, W. W.

1981-01-01

Three types of solid state power controllers (SSPC's) for high voltage, high power DC system applications were developed. The first type utilizes a SCR power switch. The second type employes an electromechanical power switch element with solid state commutation. The third type utilizes a transistor power switch. Significant accomplishments include high operating efficiencies, fault clearing, high/low temperature performance and vacuum operation.

ARC: A compact, high-field, disassemblable fusion nuclear science facility and demonstration power plant

NASA Astrophysics Data System (ADS)

Sorbom, Brandon; Ball, Justin; Palmer, Timothy; Mangiarotti, Franco; Sierchio, Jennifer; Bonoli, Paul; Kasten, Cale; Sutherland, Derek; Barnard, Harold; Haakonsen, Christian; Goh, Jon; Sung, Choongki; Whyte, Dennis

2014-10-01

The Affordable, Robust, Compact (ARC) reactor conceptual design aims to reduce the size, cost, and complexity of a combined Fusion Nuclear Science Facility (FNSF) and demonstration fusion pilot power plant. ARC is a 270 MWe tokamak reactor with a major radius of 3.3 m, a minor radius of 1.1 m, and an on-axis magnetic field of 9.2 T. ARC has Rare Earth Barium Copper Oxide (REBCO) superconducting toroidal field coils with joints to allow disassembly, allowing for removal and replacement of the vacuum vessel as a single component. Inboard-launched current drive of 25 MW LHRF power and 13.6 MW ICRF power is used to provide a robust, steady state core plasma far from disruptive limits. ARC uses an all-liquid blanket, consisting of low pressure, slowly flowing Fluorine Lithium Beryllium (FLiBe) molten salt. The liquid blanket acts as a working fluid, coolant, and tritium breeder, and minimizes the solid material that can become activated. The large temperature range over which FLiBe is liquid permits blanket operation at 800-900 K with single phase fluid cooling and allows use of a high-efficiency Brayton cycle for electricity production in the secondary coolant loop.

Multi-wavelength photoacoustic system based on high-power diode laser bars

NASA Astrophysics Data System (ADS)

Leggio, Luca; Wiśniowski, Bartosz; Gawali, Sandeep Babu; Rodríguez, Sergio; Sánchez, Miguel; Gallego, Daniel; Carpintero, Guillermo; Lamela, Horacio

2017-03-01

Multi-wavelength laser sources are necessary for a functional photoacoustic (PA) spectroscopy. The use of high-power diode lasers (HPDLs) has aroused great interest for their relatively low costs and small sizes if compared to solid state lasers. However, HPDLs are only available at few wavelengths and can deliver low optical energy (normally in the order of μJ), while diode laser bars (DLBs) offer more wavelengths in the market and can deliver more optical energy. We show the simulations of optical systems for beam coupling of single high-power DLBs operating at different wavelengths (i.e. 808 nm, 880 nm, 910 nm, 940 nm, and 980 nm) into 400-μm optical fibers. Then, in a separate design, the beams of the DLBs are combined in a compact system making use of dichroic mirrors and focusing lenses for beam coupling into a 400-μm optical fiber. The use of optical fibers with small core diameter (< 1 mm) is particularly suggestive for future photoacoustic endoscopy (PAE) applications that require interior examination of the body.

Solid-phase data from cores at the proposed Dewey Burdock uranium in-situ recovery mine, near Edgemont, South Dakota

USGS Publications Warehouse

Johnson, Raymond H.; Diehl, Sharon F.; Benzel, William M.

2013-01-01

This report releases solid-phase data from cores at the proposed Dewey Burdock uranium in-situ recovery site near Edgemont, South Dakota. These cores were collected by Powertech Uranium Corporation, and material not used for their analyses were given to the U.S. Geological Survey for additional sampling and analyses. These additional analyses included total carbon and sulfur, whole rock acid digestion for major and trace elements, 234U/238U activity ratios, X-ray diffraction, thin sections, scanning electron microscopy analyses, and cathodoluminescence. This report provides the methods and data results from these analyses along with a short summary of observations.

Multiphysics Analysis of a Solid-Core Nuclear Thermal Engine Thrust Chamber

NASA Technical Reports Server (NTRS)

Wang, Ten-See; Canabal, Francisco; Cheng, Gary; Chen, Yen-Sen

2006-01-01

The objective of this effort is to develop an efficient and accurate thermo-fluid computational methodology to predict environments for a hypothetical solid-core, nuclear thermal engine thrust chamber. The computational methodology is based on an unstructured-grid, pressure-based computational fluid dynamics methodology. Formulations for heat transfer in solids and porous media were implemented and anchored. A two-pronged approach was employed in this effort: A detailed thermo-fluid analysis on a multi-channel flow element for mid-section corrosion investigation; and a global modeling of the thrust chamber to understand the effect of hydrogen dissociation and recombination on heat transfer and thrust performance. The formulations and preliminary results on both aspects are presented.

Computer Simulation To Assess The Feasibility Of Coring Magma

NASA Astrophysics Data System (ADS)

Su, J.; Eichelberger, J. C.

2017-12-01

Lava lakes on Kilauea Volcano, Hawaii have been successfully cored many times, often with nearly complete recovery and at temperatures exceeding 1100oC. Water exiting nozzles on the diamond core bit face quenches melt to glass just ahead of the advancing bit. The bit readily cuts a clean annulus and the core, fully quenched lava, passes smoothly into the core barrel. The core remains intact after recovery, even when there are comparable amounts of glass and crystals with different coefficients of thermal expansion. The unique resulting data reveal the rate and sequence of crystal growth in cooling basaltic lava and the continuous liquid line of descent as a function of temperature from basalt to rhyolite. Now that magma bodies, rather than lava pooled at the surface, have been penetrated by geothermal drilling, the question arises as to whether similar coring could be conducted at depth, providing fundamentally new insights into behavior of magma. This situation is considerably more complex because the coring would be conducted at depths exceeding 2 km and drilling fluid pressures of 20 MPa or more. Criteria that must be satisfied include: 1) melt is quenched ahead of the bit and the core itself must be quenched before it enters the barrel; 2) circulating drilling fluid must keep the temperature of the coring assembling cooled to within operational limits; 3) the drilling fluid column must nowhere exceed the local boiling point. A fluid flow simulation was conducted to estimate the process parameters necessary to maintain workable temperatures during the coring operation. SolidWorks Flow Simulation was used to estimate the effect of process parameters on the temperature distribution of the magma immediately surrounding the borehole and of drilling fluid within the bottom-hole assembly (BHA). A solid model of the BHA was created in SolidWorks to capture the flow behavior around the BHA components. Process parameters used in the model include the fluid properties and temperature of magma, coolant flow rate, rotation speed, and rate of penetration (ROP). The modeling results indicate that there are combinations of process parameters that will provide sufficient cooling to enable the desired coring process in magma.

Chemical composition of Earth's core

NASA Astrophysics Data System (ADS)

Saxena, S.

2017-12-01

Many planetary scientists accept that the condensed planetesimals in the solar nebula eventually led to accretion of the earth. The details of the process have not been worked out. From the metallurgical experience, it is assumed that Earth's core may have formed by density differentiation with iron sinking to the core and the slag forming the mantle. This would be a post-accretionary process with temperature developing with self-compression. The problem with this hypothesis was recognized some time ago in that the seismic density profile of the core does not match the density of iron and requires the addition of a light element. Many elements such as Si, O, C and s have been proposed as diluents to decrease the density of a purely iron core. How and when this will be accomplished is still under discussion. Since the planetesimals (or condensates) formed in a well stirred nebula, it may be argued that a variety of condensed solids and fluids may have accreted and compressed without differentiation and the core does not necessarily contain mainly the differentiated iron. It is a matter of accumulating the condensate composition that would result in a density of 12 to 13 g/cm3 in the inner core. Therefore, we need a thermodynamic database that extends to 6000 K over the pressure range of ambient to 360 GPa. The development of such a database is currently in progress. It is a database with multicomponent solutions (C-Fe-Ni-S-Si) and all the major elements in the solar gas. Thermodynamic calculations using a preliminary dataset reveal that the solid species condensed at a temperature of 650 K and a pressure of 0.001 bar pressure, when self-compressed to various pressures and temperatures, yield densities that are appropriate for the mantle and core. Depending on H2/O of the escaping fluid, the formation of hydrous minerals, carbides, carbonates and iron melts with significant other elements have been found. Earth's core may have formed from solar condensate materials representing a range of solids avaeraging the seismic density of 13 kg/m3. Such material does not have to be Fe-Ni alloy but could be many different solids and a multielement alloy. Appropriate PVT equations of state have been used in arriving at this conclusion.

The formation of Uranus and Neptune in the Jupiter-Saturn region of the Solar System.

PubMed

Thommes, E W; Duncan, M J; Levison, H F

1999-12-09

Planets are believed to have formed through the accumulation of a large number of small bodies. In the case of the gas-giant planets Jupiter and Saturn, they accreted a significant amount of gas directly from the protosolar nebula after accumulating solid cores of about 5-15 Earth masses. Such models, however, have been unable to produce the smaller ice giants Uranus and Neptune at their present locations, because in that region of the Solar System the small planetary bodies will have been more widely spaced, and less tightly bound gravitationally to the Sun. When applied to the current Jupiter-Saturn zone, a recent theory predicts that, in addition to the solid cores of Jupiter and Saturn, two or three other solid bodies of comparable mass are likely to have formed. Here we report the results of model calculations that demonstrate that such cores will have been gravitationally scattered outwards as Jupiter, and perhaps Saturn, accreted nebular gas. The orbits of these cores then evolve into orbits that resemble those of Uranus and Neptune, as a result of gravitational interactions with the small bodies in the outer disk of the protosolar nebula.

Rolling dry-coupled transducers for ultrasonic inspections of aging aircraft structures

NASA Astrophysics Data System (ADS)

Komsky, Igor N.

2004-07-01

Some advanced aircraft materials or coatings are porous or otherwise sensitive to the application of water, gel, or some other ultrasonic couplants. To overcome the problems associated with the liquid coupling medium, dry-coupled rolling modules were developed at Northwestern University for the transmission of both longitudinal and transverse ultrasonic waves at frequencies up to 10 MHz. Dry-coupled ultrasonic modules contain solid core internal stators and solid or flexible external rotors with the flexible polymer substrates. Two types of the dry-coupled modules are under development. Cylindrical base transducer modules include solid core cylindrical rotors with flexible polymer substrates that rotate around the stators with ultrasonic elements. Dry-coupled modules with elongated bases contain solid core stators and flexible track-like polymer substrates that rotate around the stators as rotors of the modules. The elongated base modules have larger contact interfaces with the inspection surface in comparison with the cylindrical base modules. Some designs of the dry-coupled rolling modules contain several ultrasonic elements with different incident angles or a variable angle unit for rapid adjustments of incident angles. The prototype dry-coupled rolling modules were integrated with the portable ultrasonic inspection systems and tested on a number of Boeing aircraft structures.

Solar power satellite system definition study. Volume 4: Solid State SPS Analysis, Phase 3

NASA Technical Reports Server (NTRS)

1980-01-01

A 2500 megawatt solid ground output Solar Power Satellite (SPS) of conventional configuration was designed and analyzed. Because the power per receiving antenna is halved, as compared with the klystron reference, twice the number of receiving antennas are needed to deliver the same total power. The solid state approach appears feasible with a slightly greater specific mass and slightly higher cost than the klystron SPS design.

Direct measurement of the transition from edge to core power coupling in a light-ion helicon source

NASA Astrophysics Data System (ADS)

Piotrowicz, P. A.; Caneses, J. F.; Showers, M. A.; Green, D. L.; Goulding, R. H.; Caughman, J. B. O.; Biewer, T. M.; Rapp, J.; Ruzic, D. N.

2018-05-01

We present time-resolved measurements of an edge-to-core power transition in a light-ion (deuterium) helicon discharge in the form of infra-red camera imaging of a thin stainless steel target plate on the Proto-Material Exposure eXperiment device. The time-resolved images measure the two-dimensional distribution of power deposition in the helicon discharge. The discharge displays a mode transition characterized by a significant increase in the on-axis electron density and core power coupling, suppression of edge power coupling, and the formation of a fast-wave radial eigenmode. Although the self-consistent mechanism that drives this transition is not yet understood, the edge-to-core power transition displays characteristics that are consistent with the discharge entering a slow-wave anti-resonant regime. RF magnetic field measurements made across the plasma column, together with the power deposition results, provide direct evidence to support the suppression of the slow-wave in favor of core plasma production by the fast-wave in a light-ion helicon source.

Direct measurement of the transition from edge to core power coupling in a light-ion helicon source

DOE PAGES

Piotrowicz, Pawel A.; Caneses, Juan F.; Showers, Melissa A.; ...

2018-05-02

Here, we present time-resolved measurements of an edge-to-core power transition in a light-ion (deuterium) helicon discharge in the form of infra-red camera imaging of a thin stainless steel target plate on the Proto-Material Exposure eXperiment device. The time-resolved images measure the two-dimensional distribution of power deposition in the helicon discharge. The discharge displays a mode transition characterized by a significant increase in the on-axis electron density and core power coupling, suppression of edge power coupling, and the formation of a fast-wave radial eigenmode. Although the self-consistent mechanism that drives this transition is not yet understood, the edge-to-core power transition displaysmore » characteristics that are consistent with the discharge entering a slow-wave anti-resonant regime. RF magnetic field measurements made across the plasma column, together with the power deposition results, provide direct evidence to support the suppression of the slow-wave in favor of core plasma production by the fast-wave in a light-ion helicon source.« less

Direct measurement of the transition from edge to core power coupling in a light-ion helicon source

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

Piotrowicz, Pawel A.; Caneses, Juan F.; Showers, Melissa A.

Here, we present time-resolved measurements of an edge-to-core power transition in a light-ion (deuterium) helicon discharge in the form of infra-red camera imaging of a thin stainless steel target plate on the Proto-Material Exposure eXperiment device. The time-resolved images measure the two-dimensional distribution of power deposition in the helicon discharge. The discharge displays a mode transition characterized by a significant increase in the on-axis electron density and core power coupling, suppression of edge power coupling, and the formation of a fast-wave radial eigenmode. Although the self-consistent mechanism that drives this transition is not yet understood, the edge-to-core power transition displaysmore » characteristics that are consistent with the discharge entering a slow-wave anti-resonant regime. RF magnetic field measurements made across the plasma column, together with the power deposition results, provide direct evidence to support the suppression of the slow-wave in favor of core plasma production by the fast-wave in a light-ion helicon source.« less

Tank 241-B-108, cores 172 and 173 analytical results for the final report

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

Nuzum, J.L., Fluoro Daniel Hanford

1997-03-04

The Data Summary Table (Table 3) included in this report compiles analytical results in compliance with all applicable DQOS. Liquid subsamples that were prepared for analysis by an acid adjustment of the direct subsample are indicated by a `D` in the A column in Table 3. Solid subsamples that were prepared for analysis by performing a fusion digest are indicated by an `F` in the A column in Table 3. Solid subsamples that were prepared for analysis by performing a water digest are indicated by a I.wl. or an `I` in the A column of Table 3. Due to poormore » precision and accuracy in original analysis of both Lower Half Segment 2 of Core 173 and the core composite of Core 173, fusion and water digests were performed for a second time. Precision and accuracy improved with the repreparation of Core 173 Composite. Analyses with the repreparation of Lower Half Segment 2 of Core 173 did not show improvement and suggest sample heterogeneity. Results from both preparations are included in Table 3.« less

Melting phase relations in the Fe-S and Fe-S-O systems at core conditions in small terrestrial bodies

NASA Astrophysics Data System (ADS)

Pommier, Anne; Laurenz, Vera; Davies, Christopher J.; Frost, Daniel J.

2018-05-01

We report an experimental investigation of phase equilibria in the Fe-S and Fe-S-O systems. Experiments were performed at high temperatures (1400-1850 °C) and high pressures (14 and 20 GPa) using a multi-anvil apparatus. The results of this study are used to understand the effect of sulfur and oxygen on core dynamics in small terrestrial bodies. We observe that the formation of solid FeO grains occurs at the Fe-S liquid - Fe solid interface at high temperature ( > 1400 °C at 20 GPa). Oxygen fugacities calculated for each O-bearing sample show that redox conditions vary from ΔIW = -0.65 to 0. Considering the relative density of each phase and existing evolutionary models of terrestrial cores, we apply our experimental results to the cores of Mars and Ganymede. We suggest that the presence of FeO in small terrestrial bodies tends to contribute to outer-core compositional stratification. Depending on the redox and thermal history of the planet, FeO may also help form a transitional redox zone at the core-mantle boundary.

Determination of power distribution in the VVER-440 core on the basis of data from in-core monitors by means of a metric analysis

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

Kryanev, A. V.; Udumyan, D. K.; Kurchenkov, A. Yu., E-mail: s327@vver.kiae.ru

2014-12-15

Problems associated with determining the power distribution in the VVER-440 core on the basis of a neutron-physics calculation and data from in-core monitors are considered. A new mathematical scheme is proposed for this on the basis of a metric analysis. In relation to the existing mathematical schemes, the scheme in question improves the accuracy and reliability of the resulting power distribution.

The evolution of the moon and the terrestrial planets

NASA Technical Reports Server (NTRS)

Toksoez, M. N.; Johnston, D. H.

1974-01-01

The thermal evolutions of the Moon, Mars, Venus and Mercury are calculated theoretically starting from cosmochemical condensation models. An assortment of geological, geochemical and geophysical data are used to constrain both the present day temperatures and the thermal histories of the planets' interiors. Such data imply that the planets were heated during or shortly after formation and that all the terrestrial planets started their differentiations early in their history. The moon, smallest in size, is characterized as a differentiated body with a crust, a thick solid mantle and an interior region which may be partially molten. Mars, intermediate in size, is assumed to have differentiated an Fe-FeS core. Venus is characterized as a planet not unlike the earth in many respects. Core formation has occurred probably during the first billion years after the formation. Mercury, which probably has a large core, may have a 500 km thick solid lithosphere and a partially molten core if it is assumed that some heat sources exist in the core.

Serially connected solid oxide fuel cells having monolithic cores

DOEpatents

Herceg, J.E.

1985-05-20

Disclosed is a solid oxide fuel cell for electrochemically combining fuel and oxidant for generating galvanic output. The cell core has an array of cell segments electrically serially connected in the flow direction, each segment consisting of electrolyte walls and interconnect that are substantially devoid of any composite inert materials for support. Instead, the core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material therebetween. Means direct the fuel to the anode-exposed core passageways and means direct the oxidant to the cathode-exposed core passageways; and means also direct the galvanic output to an exterior circuit. Each layer of the electrolyte composite materials is of the order of 0.002 to 0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002 to 0.05 cm thick. Between 2 and 50 cell segments may be connected in series.

Solid state remote power controllers for 120 VDC power systems

NASA Technical Reports Server (NTRS)

Sundberg, G. R.; Baker, D. E.

1975-01-01

Solid state remote power controllers can be applied to any dc power system up to 120 Vdc and distribute power up to 3.6 kW per hour. Devices have demonstrated total electrical efficiencies of 98.5 percent to 99.0 percent at rated load currents.

Electrosprayed core-shell solid dispersions of acyclovir fabricated using an epoxy-coated concentric spray head.

PubMed

Liu, Zhe-Peng; Cui, Lei; Yu, Deng-Guang; Zhao, Zhuan-Xia; Chen, Lan

2014-01-01

A novel structural solid dispersion (SD) taking the form of core-shell microparticles for poorly water-soluble drugs is reported for the first time. Using polyvinylpyrrolidone (PVP) as a hydrophilic polymer matrix, the SDs were fabricated using coaxial electrospraying (characterized by an epoxy-coated concentric spray head), although the core fluids were unprocessable using one-fluid electrospraying. Through manipulating the flow rates of the core drug-loaded solutions, two types of core-shell microparticles with tunable drug contents were prepared. They had average diameters of 1.36±0.67 and 1.74±0.58 μm, and were essentially a combination of nanocomposites with the active ingredient acyclovir (ACY) distributed in the inner core, and the sweeter sucralose and transmembrane enhancer sodium dodecyl sulfate localized in the outer shell. Differential scanning calorimetry and X-ray diffraction results demonstrated that ACY, sodium dodecyl sulfate, and sucralose were well distributed in the PVP matrix in an amorphous state because of favorable second-order interactions. In vitro dissolution and permeation studies showed that the core-shell microparticle SDs rapidly freed ACY within 1 minute and promoted nearly eightfold increases in permeation rate across the sublingual mucosa compared with raw ACY powders.

Energy transfer in aggregated CuInS2/ZnS core-shell quantum dots deposited as solid films

NASA Astrophysics Data System (ADS)

Gardelis, S.; Fakis, M.; Droseros, N.; Georgiadou, D.; Travlos, A.; Nassiopoulou, A. G.

2017-01-01

We report on the morphology and optical properties of CuInS2/ZnS core-shell quantum dots in solid films by means of AFM, SEM, HRTEM, steady state and time-resolved photoluminescence (PL) spectroscopy. The amount of aggregation of the CuInS2/ZnS QDs was controlled by changing the preparation conditions of the films. A red-shift of the PL spectrum of CuInS2/ZnS core-shell quantum dots, deposited as solid films on silicon substrates, is observed upon increasing the amount of aggregation. The presence of larger aggregates was found to lead to a larger PL red-shift. Besides, as the degree of aggregation increased, the PL decay became slower. We attribute the observed PL red-shift to energy transfer from the smaller to the larger dots within the aggregates, with the emission being realized via a long decay recombination mechanism (100-200 ns), the origin of which is discussed.

Power Peaking Effect of OTTO Fuel Scheme Pebble Bed Reactor

NASA Astrophysics Data System (ADS)

Setiadipura, T.; Suwoto; Zuhair; Bakhri, S.; Sunaryo, G. R.

2018-02-01

Pebble Bed Reactor (PBR) type of Hight Temperature Gas-cooled Reactor (HTGR) is a very interesting nuclear reactor design to fulfill the growing electricity and heat demand with a superior passive safety features. Effort to introduce the PBR design to the market can be strengthen by simplifying its system with the Once-through-then-out (OTTO) cycle PBR in which the pebble fuel only pass the core once. Important challenge in the OTTO fuel scheme is the power peaking effect which limit the maximum nominal power or burnup of the design. Parametric survey is perform in this study to investigate the contribution of different design parameters to power peaking effect of OTTO cycle PBR. PEBBED code is utilized in this study to perform the equilibrium PBR core analysis for different design parameter and fuel scheme. The parameters include its core diameter, height-per-diameter (H/D), power density, and core nominal power. Results of this study show that diameter and H/D effectsare stronger compare to the power density and nominal core power. Results of this study might become an importance guidance for design optimization of OTTO fuel scheme PBR.

Time-dependent simulations of disk-embedded planetary atmospheres

NASA Astrophysics Data System (ADS)

Stökl, A.; Dorfi, E. A.

2014-03-01

At the early stages of evolution of planetary systems, young Earth-like planets still embedded in the protoplanetary disk accumulate disk gas gravitationally into planetary atmospheres. The established way to study such atmospheres are hydrostatic models, even though in many cases the assumption of stationarity is unlikely to be fulfilled. Furthermore, such models rely on the specification of a planetary luminosity, attributed to a continuous, highly uncertain accretion of planetesimals onto the surface of the solid core. We present for the first time time-dependent, dynamic simulations of the accretion of nebula gas into an atmosphere around a proto-planet and the evolution of such embedded atmospheres while integrating the thermal energy budget of the solid core. The spherical symmetric models computed with the TAPIR-Code (short for The adaptive, implicit RHD-Code) range from the surface of the rocky core up to the Hill radius where the surrounding protoplanetary disk provides the boundary conditions. The TAPIR-Code includes the hydrodynamics equations, gray radiative transport and convective energy transport. The results indicate that diskembedded planetary atmospheres evolve along comparatively simple outlines and in particular settle, dependent on the mass of the solid core, at characteristic surface temperatures and planetary luminosities, quite independent on numerical parameters and initial conditions. For sufficiently massive cores, this evolution ultimately also leads to runaway accretion and the formation of a gas planet.

Melting Experiments in the Fe-FeSi System at High Pressure

NASA Astrophysics Data System (ADS)

Ozawa, H.; Hirose, K.

2013-12-01

The principal light element in the Earth's core must reproduce the density jump at the inner core boundary (ICB). Silicon is thought to be a plausible light element in the core, and the melting phase relations in Fe-FeSi binary system at the ICB pressure are of great importance. Theoretical calculations on the Fe-FeSi binary system suggested that the difference in Si content between the outer core and the inner core would be too small to satisfy the observed density jump at the ICB [Alfè et al., 2002 EPSL], which requires other light elements in addition to silicon. Here we experimentally examined partitioning of silicon between liquid and solid iron up to 97 GPa. High pressure and temperature conditions were generated in a laser-heated diamond-anvil cell. Chemical compositions of co-existing quenched liquid and solid Fe-Si alloys were determined with a field-emission-type electron probe micro-analyzer. We used Fe-Si alloy containing 9 wt% Si as a starting material. Chemical analyses on the recovered samples from 39 and 49 GPa demonstrated the coexistence of quenched Si-depleted liquid and Si-enriched solid. In contrast, silicon partitions preferentially into liquid metal at 97 GPa, suggesting the starting composition (Fe-9wt% Si) lies on the iron-rich part of the eutectic. These results indicate the eutectic composition shifts toward FeSi between 49 and 97 GPa.

47 CFR 15.216 - Disclosure requirements for wireless microphones and other low power auxiliary stations capable...

Code of Federal Regulations, 2010 CFR

2010-10-01

... microphones and other low power auxiliary stations capable of operating in the core TV bands. 15.216 Section... wireless microphones and other low power auxiliary stations capable of operating in the core TV bands. (a... capable of operating in the core TV bands (channels 2-51, excluding channel 37) is subject to the...

Nanolaminated Permalloy Core for High-Flux, High-Frequency Ultracompact Power Conversion

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

Kim, J; Kim, M; Galle, P

2013-09-01

Metallic magnetic materials have desirable magnetic properties, including high permeability, and high saturation flux density, when compared with their ferrite counterparts. However, eddy-current losses preclude their use in many switching converter applications, due to the challenge of simultaneously achieving sufficiently thin laminations such that eddy currents are suppressed (e.g., 500 nm-1 mu m for megahertz frequencies), while simultaneously achieving overall core thicknesses such that substantial power can be handled. A CMOS-compatible fabrication process based on robot-assisted sequential electrodeposition followed by selective chemical etching has been developed for the realization of a core of substantial overall thickness (tens to hundreds ofmore » micrometers) comprised of multiple, stacked permalloy (Ni80Fe20) nanolaminations. Tests of toroidal inductors with nanolaminated cores showed negligible eddy-current loss relative to total core loss even at a peak flux density of 0.5 T in the megahertz frequency range. To illustrate the use of these cores, a buck power converter topology is implemented with switching frequencies of 1-2 MHz. Power conversion efficiency greater than 85% with peak operating flux density of 0.3-0.5 T in the core and converter output power level exceeding 5 W was achieved.« less

Generalized Ellipsometry on Complex Nanostructures and Low-Symmetry Materials

NASA Astrophysics Data System (ADS)

Mock, Alyssa Lynn

In this thesis, complex anisotropic materials are investigated and characterized by generalized ellipsometry. In recent years, anisotropic materials have gained considerable interest for novel applications in electronic and optoelectronic devices, mostly due to unique properties that originate from reduced crystal symmetry. Examples include white solid-state lighting devices which have become ubiquitous just recently, and the emergence of high-power, high-voltage electronic transistors and switches in all-electric vehicles. The incorporation of single crystalline material with low crystal symmetry into novel device structures requires reconsideration of existing optical characterization approaches. Here, the generalized ellipsometry concept is extended to include applications for materials with monoclinic and triclinic symmetries. A model eigendielectric displacement vector approach is developed, described and utilized to characterize monoclinic materials. Materials are investigated in spectral regions spanning from the far-infrared to the vacuum ultraviolet. Examples are demonstrated for phonon mode determination in cadmium tungstate and yttrium silicate and for band-to-band transitions in gallia (beta-Ga2O3) single crystals. Furthermore, the anisotropic optical properties of an emerging class of spatially coherent heterostructure materials with nanostructure dimensions are investigated. The so-called anisotropic effective medium approximation for slanted columnar thin films is extended to the concept of slanted columnar heterostructure thin films as well as core-shell heterostructure thin films. Examples include the determination of band-to-band transitions, phonon modes and oxidation properties of cobalt-oxide core shell structures and gas-liquid-solid distribution during controlled adsorption of organic solvents in silicon slanted columnar thin films.

Multi-physics design and analyses of long life reactors for lunar outposts

NASA Astrophysics Data System (ADS)

Schriener, Timothy M.

Future human exploration of the solar system is likely to include establishing permanent outposts on the surface of the Moon. These outposts will require reliable sources of electrical power in the range of 10's to 100's of kWe to support exploration and resource utilization activities. This need is best met using nuclear reactor power systems which can operate steadily throughout the long ˜27.3 day lunar rotational period, irrespective of location. Nuclear power systems can potentially open up the entire lunar surface for future exploration and development. Desirable features of nuclear power systems for the lunar surface include passive operation, the avoidance of single point failures in reactor cooling and the integrated power system, moderate operating temperatures to enable the use of conventional materials with proven irradiation experience, utilization of the lunar regolith for radiation shielding and as a supplemental neutron reflector, and safe post-operation decay heat removal and storage for potential retrieval. In addition, it is desirable for the reactor to have a long operational life. Only a limited number of space nuclear reactor concepts have previously been developed for the lunar environment, and these designs possess only a few of these desirable design and operation features. The objective of this research is therefore to perform design and analyses of long operational life lunar reactors and power systems which incorporate the desirable features listed above. A long reactor operational life could be achieved either by increasing the amount of highly enriched uranium (HEU) fuel in the core or by improving the neutron economy in the reactor through reducing neutron leakage and parasitic absorption. The amount of fuel in surface power reactors is constrained by the launch safety requirements. These include ensuring that the bare reactor core remains safely subcritical when submerged in water or wet sand and flooded with seawater in the unlikely event of a launch abort accident. Increasing the amount of fuel in the reactor core, and hence its operational life, would be possible by launching the reactor unfueled and fueling it on the Moon. Such a reactor would, thus, not be subject to launch criticality safety requirements. However, loading the reactor with fuel on the Moon presents a challenge, requiring special designs of the core and the fuel elements, which lend themselves to fueling on the lunar surface. This research investigates examples of both a solid core reactor that would be fueled at launch as well as an advanced concept which could be fueled on the Moon. Increasing the operational life of a reactor fueled at launch is exercised for the NaK-78 cooled Sectored Compact Reactor (SCoRe). A multi-physics design and analyses methodology is developed which iteratively couples together detailed Monte Carlo neutronics simulations with 3-D Computational Fluid Dynamics (CFD) and thermal-hydraulics analyses. Using this methodology the operational life of this compact, fast spectrum reactor is increased by reconfiguring the core geometry to reduce neutron leakage and parasitic absorption, for the same amount of HEU in the core, and meeting launch safety requirements. The multi-physics analyses determine the impacts of the various design changes on the reactor's neutronics and thermal-hydraulics performance. The option of increasing the operational life of a reactor by loading it on the Moon is exercised for the Pellet Bed Reactor (PeBR). The PeBR uses spherical fuel pellets and is cooled by He-Xe gas, allowing the reactor core to be loaded with fuel pellets and charged with working fluid on the lunar surface. The performed neutronics analyses ensure the PeBR design achieves a long operational life, and develops safe launch canister designs to transport the spherical fuel pellets to the lunar surface. The research also investigates loading the PeBR core with fuel pellets on the Moon using a transient Discrete Element Method (DEM) analysis in lunar gravity. In addition, this research addresses the post-operation storage of the SCoRe and PeBR concepts, below the lunar surface, to determine the time required for the radioactivity in the used fuel to decrease to a low level to allow for its safe recovery. The SCoRe and PeBR concepts are designed to operate at coolant temperatures ≤ 900 K and use conventional stainless steels and superalloys for the structure in the reactor core and power system. They are emplaced below grade on the Moon to take advantage of the regolith as a supplemental neutron reflector and as shielding of the lunar outpost from the reactors' neutron and gamma radiation.

Analysis of S-band solid-state transmitters for the solar power satellite

NASA Technical Reports Server (NTRS)

Belohoubek, E. F.; Ettenberg, M.; Huang, H. C.; Nowogrodzki, M.; Sechi, F. N.

1979-01-01

The possibility of replacing the Reference System antenna in which thermionic devices are used for the dc-to-microwave conversion, with solid-state elements was explored. System, device, and antenna module tradeoff investigations strongly point toward the desirability of changing the transmitter concept to a distributed array of relatively low power elements, deriving their dc power directly from the solar cell array and whose microwave power outputs are combined in space. The approach eliminates the thermal, weight, and dc-voltage distribution problems of a system in which high power tubes are simply replaced with clusters of solid state amplifiers. The proposed approach retains the important advantages of a solid state system: greatly enhanced reliability and graceful degradation of the system.

Effect of carbon, sulfur and silicon on iron melting at high pressure: Implications for composition and evolution of the planetary terrestrial cores

NASA Astrophysics Data System (ADS)

Deng, Liwei; Fei, Yingwei; Liu, Xi; Gong, Zizheng; Shahar, Anat

2013-08-01

High-pressure melting experiments in the Fe-S-C ternary and Fe-S-Si-C quaternary systems have been conducted in the range of 3.5-20 GPa and 920-1700 °C in the multi-anvil press. The mutual solubility, melting relations, and crystallization sequences were systematically investigated with changes of pressure, temperature and bulk composition. Five starting materials of Fe(84.69 wt%)-C(4.35 wt%)-S(7.85 wt%), Fe(84.87 wt%)-C(2.08 wt%)-S(11.41 wt%), Fe(86.36 wt%)-C(0.96 wt%)-S(10.31 wt%), Fe(85.71 wt%)-C(0.33 wt%)-S(11.86 wt%) and Fe(82.95 wt%)-C(0.66 wt%)-S(13.7 wt%)-Si(2.89 wt%) were employed. For Fe(84.69 wt%)-C(4.35 wt%)-S(7.85 wt%), the first crystallized phase is Fe3C at 5 GPa and Fe7C3 at 10-20 GPa. For Fe(84.87 wt%)-C(2.08 wt%)-S(11.41 wt%), Fe3C is the stable carbide at subsolidus temperature at 5-15 GPa. For Fe(86.36 wt%)-C(0.96 wt%)-S(10.31 wt%) and Fe(85.71 wt%)-C(0.33 wt%)-S(11.86 wt%), the first crystallized phase is metallic Fe instead of iron carbide at 5-10 GPa. The cotectic curves in Fe-S-C ternary system indicate only a small amount of C is needed to form an iron carbide solid inner core with the presence of S. Experiments on Fe(82.95 wt%)-C(0.66 wt%)-S(13.7 wt%)-Si(2.89 wt%) showed that a small amount of C does not significantly change the closure pressure of miscibility gap compared with that in Fe-S-Si system. It is observed that S preferentially partitions into molten iron while a significant amount of Si enters the solid phase with temperature decrease. Meanwhile, the C concentration in the liquid and solid iron metal changes little with temperature variations. If S, C and Si partitioning behavior between molten iron and solid iron metal with temperature remains the same under Earth's present core pressure conditions, the solid inner core should be iron dominated with dissolved Si. On the other hand, the liquid outer core will be S rich and Si poor. Moderate carbon will be evenly present in both solid and liquid cores. Based on our melting data in a multi-component system, no layered liquid core should exist in the Earth, Mars and Mercury.

Analysis of C/E results of fission rate ratio measurements in several fast lead VENUS-F cores

NASA Astrophysics Data System (ADS)

Kochetkov, Anatoly; Krása, Antonín; Baeten, Peter; Vittiglio, Guido; Wagemans, Jan; Bécares, Vicente; Bianchini, Giancarlo; Fabrizio, Valentina; Carta, Mario; Firpo, Gabriele; Fridman, Emil; Sarotto, Massimo

2017-09-01

During the GUINEVERE FP6 European project (2006-2011), the zero-power VENUS water-moderated reactor was modified into VENUS-F, a mock-up of a lead cooled fast spectrum system with solid components that can be operated in both critical and subcritical mode. The Fast Reactor Experiments for hybrid Applications (FREYA) FP7 project was launched in 2011 to support the designs of the MYRRHA Accelerator Driven System (ADS) and the ALFRED Lead Fast Reactor (LFR). Three VENUS-F critical core configurations, simulating the complex MYRRHA core design and one configuration devoted to the LFR ALFRED core conditions were investigated in 2015. The MYRRHA related cores simulated step by step design peculiarities like the BeO reflector and in pile sections. For all of these cores the fuel assemblies were of a simple design consisting of 30% enriched metallic uranium, lead rodlets to simulate the coolant and Al2O3 rodlets to simulate the oxide fuel. Fission rate ratios of minor actinides such as Np-237, Am-241 as well as Pu-239, Pu-240, Pu-242 and U-238 to U-235 were measured in these VENUS-F critical assemblies with small fission chambers in specially designed locations, to determine the spectral indices in the different neutron spectrum conditions. The measurements have been analyzed using advanced computational tools including deterministic and stochastic codes and different nuclear data sets like JEFF-3.1, JEFF-3.2, ENDF/B7.1 and JENDL-4.0. The analysis of the C/E discrepancies will help to improve the nuclear data in the specific energy region of fast neutron reactor spectra.

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

Baek, M. H.; Kim, S. J.; Yoo, J.

The major roles of a prototype SFR are to provide irradiation test capability for the fuel and structure materials, and to obtain operational experiences of systems. Due to a compromise between the irradiation capability and construction costs, the power level should be properly determined. In this paper, a trade-off study on the power level of the prototype SFR was performed from a neutronics viewpoint. To select candidate cores, the parametric study of pin diameters was estimated using 20 wt.% uranium fuel. The candidate cores of different power levels, 125 MWt, 250 MWt, 400 MWt, and 500 MWt, were compared withmore » the 1500 MWt reference core. The resulting core performance and economic efficiency indices became insensitive to the power at about 400-500 MWt and sharply deteriorated at about 125-250 MWt with decreasing core sizes. Fuel management scheme, TRU core performance comparing with uranium core, and sodium void reactivity were also evaluated with increasing power levels. It is found that increasing the number of batches showed higher burnup performance and economic efficiency. However, increasing the cycle length showed the trends in lower economic efficiency. Irradiation performance of TRU and enriched TRU cores was improved about 20 % and 50 %, respectively. The maximum sodium void reactivity of 5.2$ was confirmed less than the design limit of 7.5$. As a result, the power capacity of the prototype SFR should not be less than 250 MWt and would be appropriate at {approx} 500 MWt considering the performance and economic efficiency. (authors)« less

Thermal Equation of State of Iron: Constraint on the Density Deficit of Earth's Core

NASA Astrophysics Data System (ADS)

Fei, Y.; Murphy, C. A.; Shibazaki, Y.; Huang, H.

2013-12-01

The seismically inferred densities of Earth's solid inner core and the liquid outer core are smaller than the measured densities of solid hcp-iron and liquid iron, respectively. The inner core density deficit is significantly smaller than the outer core density deficit, implying different amounts and/or identities of light-elements incorporated in the inner and outer cores. Accurate measurements of the thermal equation-of-state of iron over a wide pressure and temperature range are required to precisely quantify the core density deficits, which are essential for developing a quantitative composition model for the core. The challenge has been evaluating the experimental uncertainties related to the choice of pressure scales and the sample environment, such as hydrostaticity at multi-megabar pressures and extreme temperatures. We have conducted high-pressure experiments on iron in MgO, NaCl, and Ne pressure media and obtained in-situ X-ray diffraction data up to 200 GPa at room temperature. Using inter-calibrated pressure scales including the MgO, NaCl, Ne, and Pt scales, we have produced a consistent compression curve of hcp-Fe at room temperature. We have also performed laser-heated diamond-anvil cell experiments on both Fe and Pt in a Ne pressure medium. The experiment was designed to quantitatively compare the thermal expansion of Fe and Pt in the same sample environment using Ne as the pressure medium. The thermal expansion data of hcp-Fe at high pressure were derived based on the thermal equation of state of Pt. Using the 300-K isothermal compression curve of iron derived from our static experiments as a constraint, we have developed a thermal equation of state of hcp-Fe that is consistent with the static P-V-T data of iron and also reproduces the shock wave Hugoniot data for pure iron. The thermodynamic model, based on both static and dynamic data, is further used to calculate the density and bulk sound velocity of liquid iron. Our results define the solid inner core and liquid outer core density deficits, which can serve as the basis for any core composition models.

Accelerator driven sub-critical core

DOEpatents

McIntyre, Peter M; Sattarov, Akhdiyor

2015-03-17

Systems and methods for operating an accelerator driven sub-critical core. In one embodiment, a fission power generator includes a sub-critical core and a plurality of proton beam generators. Each of the proton beam generators is configured to concurrently provide a proton beam into a different area of the sub-critical core. Each proton beam scatters neutrons within the sub-critical core. The plurality of proton beam generators provides aggregate power to the sub-critical core, via the proton beams, to scatter neutrons sufficient to initiate fission in the sub-critical core.

Comparison of the fractional power motor with cores made of various magnetic materials

NASA Astrophysics Data System (ADS)

Gmyrek, Zbigniew; Lefik, Marcin; Cavagnino, Andrea; Ferraris, Luca

2017-12-01

The optimization of the motor cores, coupled with new core shapes as well as powering the motor at high frequency are the primary reasons for the use of new materials. The utilization of new materials, like SMC (soft magnetic composite), reduce the core loss and/or provide quasi-isotropic core's properties in any magnetization direction. Moreover, the use of SMC materials allows for avoiding degradation of the material portions, resulting from punching process, thereby preventing the deterioration of operating parameters of the motor. The authors examine the impact of technological parameters on the properties of a new type of SMC material and analyze the possibility of its use as the core of the fractional power motor. The result of the work is an indication of the shape of the rotor core made of a new SMC material to achieve operational parameters similar to those that have a motor with a core made of laminations.

How Inge Lehmann Discovered the Inner Core of the Earth

ERIC Educational Resources Information Center

Rousseau, Christiane

2013-01-01

The mathematics behind Inge Lehmann's discovery that the inner core of the Earth is solid is explained using data collected around the Earth on seismic waves and their travel time through the Earth.

Preparation of microcapsules with self-microemulsifying core by a vibrating nozzle method.

PubMed

Homar, Miha; Suligoj, Dasa; Gasperlin, Mirjana

2007-02-01

Incorporation of drugs in self-microemulsifying systems (SMES) offers several advantages for their delivery, the main one being faster drug dissolution and absorption. Formulation of SMES in solid dosage forms can be difficult and, to date, most SMES are applied in liquid dosage form or soft gelatin capsules. This study has explored the incorporation of SMES in microcapsules, which could then be used for formulation of solid dosage forms. An Inotech IE-50 R encapsulator equipped with a concentric nozzle was used to produce alginate microcapsules with a self-microemulsifying core. Retention of the core phase was improved by optimization of encapsulator parameters and modification of the shell forming phase and hardening solution. The mean encapsulation efficiency of final batches was more than 87%, which resulted in 0.07% drug loading. It was demonstrated that production of microcapsules with a self-microemulsifying core is possible and that the process is stable and reproducible.

Atmospheric Mining in the Outer Solar System: Outer Planet In-Space Bases and Moon Bases for Resource Processing

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2017-01-01

Atmospheric mining in the outer solar system has been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as Helium 3 (3He) and deuterium can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and deuterium were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses were undertaken to investigate resource capturing aspects of atmospheric mining in the outer solar system. This included the gas capturing rate, storage options, and different methods of direct use of the captured gases. While capturing 3He, large amounts of hydrogen and 4He are produced. The propulsion and transportation requirements for all of the major moons of Uranus and Neptune are presented. Analyses of orbital transfer vehicles (OTVs), landers, factories, and the issues with in-situ resource utilization (ISRU) low gravity processing factories are included. Preliminary observations are presented on near-optimal selections of moon base orbital locations, OTV power levels, and OTV and lander rendezvous points. Several artificial gravity in-space base designs and orbital sites at Uranus and Neptune and the OTV requirements to support them are also addressed.

Atmospheric Mining in the Outer Solar System: Resource Capturing, Exploration, and Exploitation

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2015-01-01

Atmospheric mining in the outer solar system (AMOSS) has been investigated as a means of fuel production for high-energy propulsion and power. Fusion fuels such as helium 3 (He-3) and hydrogen can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. 3He and hydrogen (deuterium, etc.) were the primary gases of interest, with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses were undertaken to investigate resource capturing aspects of AMOSS. These analyses included the gas capturing rate, storage options, and different methods of direct use of the captured gases. Additional supporting analyses were conducted to illuminate vehicle sizing and orbital transportation issues. While capturing 3He, large amounts of hydrogen and helium 4 (He-4) are produced. With these two additional gases, the potential exists for fueling small and large fleets of additional exploration and exploitation vehicles. Additional aerospacecraft or other aerial vehicles (UAVs, balloons, rockets, etc.) could fly through the outer-planet atmosphere to investigate cloud formation dynamics, global weather, localized storms or other disturbances, wind speeds, the poles, and so forth. Deep-diving aircraft (built with the strength to withstand many atmospheres of pressure) powered by the excess hydrogen or 4He may be designed to probe the higher density regions of the gas giants.

Gravity Field and Internal Structure of Mercury from MESSENGER

NASA Technical Reports Server (NTRS)

Smith, David E.; Zuber, Maria T.; Phillips, Roger J.; Solomon, Sean C.; Hauck, Steven A., II; Lemoine, Frank G.; Mazarico, Erwan; Neumann, Gregory A.; Peale, Stanton J.; Margot, Jean-Luc;

Gravity field and internal structure of Mercury from MESSENGER.

PubMed

Smith, David E; Zuber, Maria T; Phillips, Roger J; Solomon, Sean C; Hauck, Steven A; Lemoine, Frank G; Mazarico, Erwan; Neumann, Gregory A; Peale, Stanton J; Margot, Jean-Luc; Johnson, Catherine L; Torrence, Mark H; Perry, Mark E; Rowlands, David D; Goossens, Sander; Head, James W; Taylor, Anthony H

2012-04-13

Radio tracking of the MESSENGER spacecraft has provided a model of Mercury's gravity field. In the northern hemisphere, several large gravity anomalies, including candidate mass concentrations (mascons), exceed 100 milli-Galileos (mgal). Mercury's northern hemisphere crust is thicker at low latitudes and thinner in the polar region and shows evidence for thinning beneath some impact basins. The low-degree gravity field, combined with planetary spin parameters, yields the moment of inertia C/MR(2) = 0.353 ± 0.017, where M and R are Mercury's mass and radius, and a ratio of the moment of inertia of Mercury's solid outer shell to that of the planet of C(m)/C = 0.452 ± 0.035. A model for Mercury's radial density distribution consistent with these results includes a solid silicate crust and mantle overlying a solid iron-sulfide layer and an iron-rich liquid outer core and perhaps a solid inner core.

Development of hydrogel TentaGel shell-core beads for ultrahigh throughput solution-phase screening of encoded OBOC combinatorial small molecule libraries.

PubMed

Baek, Hyoung Gee; Liu, Ruiwu; Lam, Kit S

2009-01-01

The one-bead one-compound (OBOC) combinatorial library method enables the rapid generation and screening of millions of discrete chemical compounds on beads. Most of the OBOC screening methods require the library compounds to remain tethered to the bead during screening process. Methods have also been developed to release library compounds from immobilized beads for in situ solution phase or "lawn" assays. However, this latter approach, while extremely powerful, is severely limited by the lack of suitable solid supports for such assays. Here, we report on the development of a novel hydrogel TentaGel shell-core (HTSC) bead in which hydrogel is grafted onto the polystyrene-based TentaGel (TG) bead as an outer shell (5-80 mum thick) via free radical surface-initiated polymerization. This novel shell-core bilayer resin enables the preparation of encoded OBOC combinatorial small molecule libraries, such that the library compounds reside on the highly hydrophilic outer layer and the coding tags reside in the polystyrene-based TG core. Using fluorescein as a model small molecule compound, we have demonstrated that fluorescein molecules that have been linked covalently to the hydrogel shell via a disulfide bond could readily diffuse out of the hydrogel layer into the bead surrounding after reduction with dithiothreitol. In contrast, under identical condition, the released fluorescein molecules remained bound to unmodified TG bead. We have prepared an encoded OBOC small molecule library on the novel shell-core beads and demonstrated that the beads can be readily decoded.

An Overview of Power, Energy Storage, and Conversion Efforts for 2014 SBIR Phases I and II

NASA Technical Reports Server (NTRS)

Nguyen, Hung D.; Steele, Gynelle C.

2016-01-01

Technological innovation is the overall focus of NASA's Small Business Innovation Research (SBIR) program. The program invests in the development of innovative concepts and technologies to help NASA's mission directorates address critical research and development needs for agency projects. NASA's Small Business Innovation Research (SBIR) program focuses on technological innovation by investing in development of innovative concepts and technologies to help NASA mission directorates address critical research needs for Agency programs. This report highlights 15 of the innovative SBIR 2014 Phase I and II projects that focus on one of NASA Glenn Research Center's six core competencies-Power, Energy Storage and Conversion. The technologies cover a wide spectrum of applications such as high-radiation-tolerant ceramic voltage isolators, development of hermetic sealing glasses for solid oxide fuel cells, rechargeable lithium metal cells, high-efficiency direct methane solid oxide fuel cell systems, Li metal protection for high-energy space batteries, isolated bidirectional direct current converters for distributed battery energy applications, and high-efficiency rad-hard ultrathin Si photovoltaic cell technology for space. Each article describes an innovation and technical objective and highlights NASA commercial and industrial applications. This report provides an opportunity for NASA engineers, researchers, and program managers to learn how NASA SBIR technologies could help their programs and projects, and lead to collaborations and partnerships between the small SBIR companies and NASA that would benefit both.

Design and implementation of a simple nuclear power plant simulator

NASA Astrophysics Data System (ADS)

Miller, William H.

1983-02-01

A simple PWR nuclear power plant simulator has been designed and implemented on a minicomputer system. The system is intended for students use in understanding the power operation of a nuclear power plant. A PDP-11 minicomputer calculates reactor parameters in real time, uses a graphics terminal to display the results and a keyboard and joystick for control functions. Plant parameters calculated by the model include the core reactivity (based upon control rod positions, soluble boron concentration and reactivity feedback effects), the total core power, the axial core power distribution, the temperature and pressure in the primary and secondary coolant loops, etc.

Advanced nuclear thermal propulsion concepts

NASA Technical Reports Server (NTRS)

Howe, Steven D.

1993-01-01

In 1989, a Presidential directive created the Space Exploration Initiative (SEI) which had a goal of placing mankind on Mars in the early 21st century. The SEI was effectively terminated in 1992 with the election of a new administration. Although the initiative did not exist long enough to allow substantial technology development, it did provide a venue, for the first time in 20 years, to comprehensively evaluate advanced propulsion concepts which could enable fast, manned transits to Mars. As part of the SEI based investigations, scientists from NASA, DoE National Laboratories, universities, and industry met regularly and proceeded to examine a variety of innovative ideas. Most of the effort was directed toward developing a solid-core, nuclear thermal rocket and examining a high-power nuclear electric propulsion system. In addition, however, an Innovative Concepts committee was formed and charged with evaluating concepts that offered a much higher performance but were less technologically mature. The committee considered several concepts and eventually recommended that further work be performed in the areas of gas core fission rockets, inertial confinement fusion systems, antimatter based rockets, and gas core fission electric systems. Following the committee's recommendations, some computational modeling work has been performed at Los Alamos in certain of these areas and critical issues have been identified.

Nasicon-Type Surface Functional Modification in Core-Shell LiNi0.5Mn0.3Co0.2O2@NaTi2(PO4)3 Cathode Enhances Its High-Voltage Cycling Stability and Rate Capacity toward Li-Ion Batteries.

PubMed

Liang, Longwei; Sun, Xuan; Wu, Chen; Hou, Linrui; Sun, Jinfeng; Zhang, Xiaogang; Yuan, Changzhou

2018-02-14

Surface modifications are established well as efficient methodologies to enhance comprehensive Li-storage behaviors of the cathodes and play a significant role in cutting edge innovations toward lithium-ion batteries (LIBs). Herein, we first logically devised a pilot-scale coating strategy to integrate solid-state electrolyte NaTi 2 (PO 4 ) 3 (NTP) and layered LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC) for smart construction of core-shell NMC@NTP cathodes. The Nasicon-type NTP nanoshell with exceptional ion conductivity effectively suppressed gradual encroachment and/or loss of electroactive NMC, guaranteed stable phase interfaces, and meanwhile rendered small sur-/interfacial electron/ion-diffusion resistance. By benefiting from immanently promoting contributions of the nano-NTP coating, the as-fabricated core-shell NMC@NTP architectures were competitively endowed with superior high-voltage cyclic stabilities and rate capacities within larger electrochemical window from 3.0 to 4.6 V when utilized as advanced cathodes for advanced LIBs. More meaningfully, the appealing electrode design concept proposed here will exert significant impact upon further constructing other high-voltage Ni-based cathodes for high-energy/power LIBs.

Optimize out-of-core thermionic energy conversion for nuclear electric propulsion

NASA Technical Reports Server (NTRS)

Morris, J. F.

1977-01-01

Current designs for out of core thermionic energy conversion (TEC) to power nuclear electric propulsion (NEP) were evaluated. Approaches to improve out of core TEC are emphasized and probabilities for success are indicated. TEC gains are available with higher emitter temperatures and greater power densities. Good potentialities for accommodating external high temperature, high power density TEC with heat pipe cooled reactors exist.

Leaching kinetics of bottom ash waste as a source of calcium ions.

PubMed

Koech, Lawrence; Everson, Ray; Neomagus, Hein; Rutto, Hilary

2015-02-01

Bottom ash is a waste material from coal-fired power plants, and it is known to contain elements that are potentially toxic at high concentration levels when disposed in landfills. This study investigates the use of bottom ash as a partial substitute sorbent for wet flue gas desulfurization (FGD) processes by focusing on its leaching kinetics in adipic acid. This was studied basing on the shrinking core model that was applied to the experimental data obtained by the authors presented at the International Conference on Industrial, Manufacturing, Automation and Mechanical Engineering, Johannesburg, South Africa, November 27-28, 2013) on dissolution of bottom ash. The leaching rate constant was obtained from different reaction variables, namely, temperature, pH, acid concentration, and solid-to-liquid ratio, that could affect the leaching process. The solid sample of bottom ash was characterized at different leaching periods using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that solid-to-liquid ratio had a significant effect on the leaching rate constant when compared with other variables. The leaching kinetics showed that diffusion through the product layer was the rate-controlling step during leaching, and the activation energy for the process was found to be 18.92 kJ/mol.

Optical fiber sensor having an active core

NASA Technical Reports Server (NTRS)

Egalon, Claudio Oliveira (Inventor); Rogowski, Robert S. (Inventor)

1993-01-01

An optical fiber is provided. The fiber is comprised of an active fiber core which produces waves of light upon excitation. A factor ka is identified and increased until a desired improvement in power efficiency is obtained. The variable a is the radius of the active fiber core and k is defined as 2 pi/lambda wherein lambda is the wavelength of the light produced by the active fiber core. In one embodiment, the factor ka is increased until the power efficiency stabilizes. In addition to a bare fiber core embodiment, a two-stage fluorescent fiber is provided wherein an active cladding surrounds a portion of the active fiber core having an improved ka factor. The power efficiency of the embodiment is further improved by increasing a difference between the respective indices of refraction of the active cladding and the active fiber core.

NASA Collaborative Design Processes

NASA Technical Reports Server (NTRS)

Jones, Davey

2017-01-01

This is Block 1, the first evolution of the world's most powerful and versatile rocket, the Space Launch System, built to return humans to the area around the moon. Eventually, larger and even more powerful and capable configurations will take astronauts and cargo to Mars. On the sides of the rocket are the twin solid rocket boosters that provide more than 75 percent during liftoff and burn for about two minutes, after which they are jettisoned, lightening the load for the rest of the space flight. Four RS-25 main engines provide thrust for the first stage of the rocket. These are the world's most reliable rocket engines. The core stage is the main body of the rocket and houses the fuel for the RS-25 engines, liquid hydrogen and liquid oxygen, and the avionics, or "brain" of the rocket. The core stage is all new and being manufactured at NASA's "rocket factory," Michoud Assembly Facility near New Orleans. The Launch Vehicle Stage Adapter, or LVSA, connects the core stage to the Interim Cryogenic Propulsion Stage. The Interim Cryogenic Propulsion Stage, or ICPS, uses one RL-10 rocket engine and will propel the Orion spacecraft on its deep-space journey after first-stage separation. Finally, the Orion human-rated spacecraft sits atop the massive Saturn V-sized launch vehicle. Managed out of Johnson Space Center in Houston, Orion is the first spacecraft in history capable of taking humans to multiple destinations within deep space. 2) Each element of the SLS utilizes collaborative design processes to achieve the incredible goal of sending human into deep space. Early phases are focused on feasibility and requirements development. Later phases are focused on detailed design, testing, and operations. There are 4 basic phases typically found in each phase of development.

Theoretical and experimental study of bent fully aperiodic large-pitch fibers for enhancing the high-order modes delocalization

NASA Astrophysics Data System (ADS)

du Jeu, Rémi; Dauliat, Romain; Darwich, Dia; Auguste, Jean-Louis; Benoît, Aurélien; Leconte, Baptiste; Malleville, Marie-Alicia; Jamier, Raphaël.; Schuster, Kay; Roy, Philippe

2018-02-01

The power scaling of fiber lasers and amplifiers has triggered an extensive development of large-mode area fibers among which the most promising are the distributed mode filtering fibers and the large-pitch fibers. These structures enable for an effective higher-order modes delocalization and subsequently a singlemode emission. An interesting alternative consists in using the fully-aperiodic large-pitch fibers, into which the standard air-silica photonic crystal cladding is replaced by an aperiodic pattern made of solid low-index inclusions cladding. However, in such a structure, the core and the background cladding material surrounding it must have rigorously the same refractive index. Current synthesis processes and measurement techniques offer respectively a maximum resolution of 5×10-4 and 1×10-4 while the indexmatching must be as precise as 1×10-5 . Lately a gain material with a refractive index 1.5×10-4 higher than that of the background cladding material was fabricated, thus re-confining the first higher-order modes in the core. A numerical study is carried out on the benefit of bending such fully-aperiodic fiber to counteract this phenomenon. Optimized bending axis and radius have been determined. Experiments are done in a laser cavity operating at 1030 nm using an 88cm-long 51μm core diameter ytterbium-doped fiber. Results demonstrate an improvement of the M2 from 1.7 when the fiber is kept straight to 1.2 when it is bent with a 100 to 60 cm bend radius. These primary results are promising for future power scaling.

Numerical Simulations of Single Flow Element in a Nuclear Thermal Thrust Chamber

NASA Technical Reports Server (NTRS)

Cheng, Gary; Ito, Yasushi; Ross, Doug; Chen, Yen-Sen; Wang, Ten-See

2007-01-01

The objective of this effort is to develop an efficient and accurate computational methodology to predict both detailed and global thermo-fluid environments of a single now element in a hypothetical solid-core nuclear thermal thrust chamber assembly, Several numerical and multi-physics thermo-fluid models, such as chemical reactions, turbulence, conjugate heat transfer, porosity, and power generation, were incorporated into an unstructured-grid, pressure-based computational fluid dynamics solver. The numerical simulations of a single now element provide a detailed thermo-fluid environment for thermal stress estimation and insight for possible occurrence of mid-section corrosion. In addition, detailed conjugate heat transfer simulations were employed to develop the porosity models for efficient pressure drop and thermal load calculations.

KSI's Cross Insulated Core Transformer Technology

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

Uhmeyer, Uwe

2009-08-04

Cross Insulated Core Transformer (CCT) technology improves on Insulated Core Transformer (ICT) implementations. ICT systems are widely used in very high voltage, high power, power supply systems. In an ICT transformer ferrite core sections are insulated from their neighboring ferrite cores. Flux leakage is present at each of these insulated gaps. The flux loss is raised to the power of stages in the ICT design causing output voltage efficiency to taper off with increasing stages. KSI's CCT technology utilizes a patented technique to compensate the flux loss at each stage of an ICT system. Design equations to calculate the fluxmore » compensation capacitor value are presented. CCT provides corona free operation of the HV stack. KSI's CCT based High Voltage power supply systems offer high efficiency operation, high frequency switching, low stored energy and smaller size over comparable ICT systems.« less

High-power picosecond pulse delivery through hollow core photonic band gap fibers

NASA Astrophysics Data System (ADS)

Michieletto, Mattia; Johansen, Mette M.; Lyngsø, Jens K.; Lægsgaard, Jesper; Bang, Ole; Alkeskjold, Thomas T.

2016-03-01

We demonstrated robust and bend insensitive fiber delivery of high power laser with diffraction limited beam quality for two different kinds of hollow core band gap fibers. The light source for this experiment consists of ytterbium-doped double clad fiber aeroGAIN-ROD-PM85 in a high power amplifier setup. It provided 22ps pulses with a maximum average power of 95W, 40MHz repetition rate at 1032nm (~2.4μJ pulse energy), with M2 <1.3. We determined the facet damage threshold for a 7-cells hollow core photonic bandgap fiber and showed up to 59W average power output for a 5 meters fiber. The damage threshold for a 19-cell hollow core photonic bandgap fiber exceeded the maximum power provided by the light source and up to 76W average output power was demonstrated for a 1m fiber. In both cases, no special attention was needed to mitigate bend sensitivity. The fibers were coiled on 8 centimeters radius spools and even lower bending radii were present. In addition, stimulated rotational Raman scattering arising from nitrogen molecules was measured through a 42m long 19 cell hollow core fiber.

Maintenance Resources by Building Use for U.S. Army Installations. Volume 3. Appendices I through P

DTIC Science & Technology

1991-05-01

floor I____ ______ __ Solid core (safety 0423230 10 2.78 glass ) painted exterior door Drinking fountain 081 1HOO _______6 1.77 Wood, finished 0415FI0...Concrete, finished 062B200 25 1.15 flooring Solid core wood 0423230 26 1.12 (safety glass ) paint exterior door Safety switch, 1122100 27 1.07 enclosed...exterior, 1st floor Steel frame 0431210 26 1.04 (painted) operable window, 1st floor Steel (w/safety 0421220 27 1.04 glass ) painted exterior door Pipe

KSC-2011-2440

NASA Image and Video Library

2011-03-23

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., test the electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2443

NASA Image and Video Library

2011-03-23

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., test the electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2488

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2325

NASA Image and Video Library

2011-03-16

TITUSVILLE, Fla. -- A solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter is unpacked in the Astrotech payload processing facility in Titusville, Fla. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2487

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., begin to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2326

NASA Image and Video Library

2011-03-16

TITUSVILLE, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unpack a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2339

NASA Image and Video Library

2011-03-17

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., begin processing a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2486

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2491

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2484

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2438

NASA Image and Video Library

2011-03-23

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to test the electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2447

NASA Image and Video Library

2011-03-23

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., test the electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2485

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2346

NASA Image and Video Library

2011-03-17

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., check out an unfurled solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2442

NASA Image and Video Library

2011-03-23

CAPE CANAVERAL, Fla. -- The electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter is tested in the Astrotech payload processing facility in Titusville, Fla. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2337

NASA Image and Video Library

2011-03-17

CAPE CANAVERAL, Fla. -- A solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter is unpacked in the Astrotech payload processing facility in Titusville, Fla. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2338

NASA Image and Video Library

2011-03-17

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unpack a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2344

NASA Image and Video Library

2011-03-17

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2342

NASA Image and Video Library

2011-03-17

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., begin to unfurl a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2327

NASA Image and Video Library

2011-03-16

TITUSVILLE, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unpack a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2492

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., check out solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2489

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2446

NASA Image and Video Library

2011-03-23

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., test the electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2343

NASA Image and Video Library

2011-03-17

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2490

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2479

NASA Image and Video Library

2011-03-26

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare to unfurl solar array No. 1 with a magnetometer boom that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2334

NASA Image and Video Library

2011-03-16

TITUSVILLE, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., process a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2333

NASA Image and Video Library

2011-03-16

TITUSVILLE, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., process a solar panel that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2441

NASA Image and Video Library

2011-03-23

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., test the electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2439

NASA Image and Video Library

2011-03-23

CAPE CANAVERAL, Fla. -- The electrical continuity of a solar array that will help power NASA's Juno spacecraft on a mission to Jupiter is tested in the Astrotech payload processing facility in Titusville, Fla. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

NASA Tech Briefs, July 2005

NASA Technical Reports Server (NTRS)

2005-01-01

Thin-Film Resistance Heat-Flux Sensors Circuit Indicates that Voice-Recording Disks are Nearly Full Optical Sensing of Combustion Instabilities in Gas Turbines Topics include: Crane-Load Contact Sensor; Hexagonal and Pentagonal Fractal Multiband Antennas; Multifunctional Logic Gate Controlled by Temperature; Multifunctional Logic Gate Controlled by Supply Voltage; Power Divider for Waveforms Rich in Harmonics; SCB Quantum Computers Using iSWAP and 1-Qubit Rotations; CSAM Metrology Software Tool; Update on Rover Sequencing and Visualization Program; Selecting Data from a Star Catalog; Rotating Desk for Collaboration by Two Computer Programmers; Variable-Pressure Washer; Magnetically Attached Multifunction Maintenance Rover; Improvements in Fabrication of Sand/Binder Cores for Casting; Solid Freeform Fabrication of Composite-Material Objects; Efficient Computational Model of Hysteresis; Gauges for Highly Precise Metrology of a Compound Mirror; Improved Electrolytic Hydrogen Peroxide Generator; High-Power Fiber Lasers Using Photonic Band Gap Materials; Ontology-Driven Information Integration; Quantifying Traversability of Terrain for a Mobile Robot; More About Arc-Welding Process for Making Carbon Nanotubes; Controlling Laser Spot Size in Outer Space; or Software-Reconfigurable Processors for Spacecraft.

Environment-based pin-power reconstruction method for homogeneous core calculations

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

Leroyer, H.; Brosselard, C.; Girardi, E.

2012-07-01

Core calculation schemes are usually based on a classical two-step approach associated with assembly and core calculations. During the first step, infinite lattice assemblies calculations relying on a fundamental mode approach are used to generate cross-sections libraries for PWRs core calculations. This fundamental mode hypothesis may be questioned when dealing with loading patterns involving several types of assemblies (UOX, MOX), burnable poisons, control rods and burn-up gradients. This paper proposes a calculation method able to take into account the heterogeneous environment of the assemblies when using homogeneous core calculations and an appropriate pin-power reconstruction. This methodology is applied to MOXmore » assemblies, computed within an environment of UOX assemblies. The new environment-based pin-power reconstruction is then used on various clusters of 3x3 assemblies showing burn-up gradients and UOX/MOX interfaces, and compared to reference calculations performed with APOLLO-2. The results show that UOX/MOX interfaces are much better calculated with the environment-based calculation scheme when compared to the usual pin-power reconstruction method. The power peak is always better located and calculated with the environment-based pin-power reconstruction method on every cluster configuration studied. This study shows that taking into account the environment in transport calculations can significantly improve the pin-power reconstruction so far as it is consistent with the core loading pattern. (authors)« less

Propulsion and Power Rapid Response R&D Support Delivery Order 0041: Power Dense Solid Oxide Fuel Cell Systems: High Performance, High Power Density Solid Oxide Fuel Cells - Materials and Load Control

DTIC Science & Technology

2008-12-01

respectively. 2.3.1.2 Brushless DC Motor Brushless direct current ( BLDC ) motors feature high efficiency, ease of control , and astonishingly high power...modeling purposes, we ignore the modeling complexity of the BLDC controller and treat the motor and controller “as commutated”, i.e. we assume the...High Performance, High Power Density Solid Oxide Fuel Cells− Materials and Load Control Stephen W. Sofie, Steven R. Shaw, Peter A. Lindahl, and Lee H

A hybrid electromechanical solid state switch for ac power control

NASA Technical Reports Server (NTRS)

1972-01-01

Bidirectional thyristor coupled to a series of actuator driven electromechanical contacts generates hybrid electromechanical solid state switch for ac power control. Device is useful in power control applications where zero crossover switching is required.

The effect of macro-bending on power confinement factor in single mode fibers

NASA Astrophysics Data System (ADS)

Waluyo, T. B.; Bayuwati, D.; Mulyanto, I.

2018-03-01

One of the methods to determine the macro-bending effect in a single mode fiber is by calculating its power loss coefficient. We describe an alternative method by using the equation of fractional power in the fiber core. Knowing the fiber parameters such as its core radius, refractive indexes, and operating wavelength; we can calculate the V-number and the fractional power in the core. Because the value of the fiber refractive indexes and the propagation constant are affected by bending, we can calculate the value of the fractional power in the core as a function of the bending radius. We calculate the fractional power in the core of an SMF28 and SM600 fiber and, to verify our calculation, we measure its transmission loss using an optical spectrum analyzer. Our calculations and experimental results showed that for SMF28 fiber, there is about 4% power loss due to bending at 633 nm, about 8% at 1310 nm, about 20% at 1550 nm, and about 60% at 1064 nm. For SM600 fiber, there is about 6% power loss due to bending at 633 nm, about 11% at 850 nm, and this fiber is not suitable for operating wavelength beyond 1000 nm.

The change of radial power factor distribution due to RCCA insertion at the first cycle core of AP1000

NASA Astrophysics Data System (ADS)

Susilo, J.; Suparlina, L.; Deswandri; Sunaryo, G. R.

2018-02-01

The using of a computer program for the PWR type core neutronic design parameters analysis has been carried out in some previous studies. These studies included a computer code validation on the neutronic parameters data values resulted from measurements and benchmarking calculation. In this study, the AP1000 first cycle core radial power peaking factor validation and analysis were performed using CITATION module of the SRAC2006 computer code. The computer code has been also validated with a good result to the criticality values of VERA benchmark core. The AP1000 core power distribution calculation has been done in two-dimensional X-Y geometry through ¼ section modeling. The purpose of this research is to determine the accuracy of the SRAC2006 code, and also the safety performance of the AP1000 core first cycle operating. The core calculations were carried out with the several conditions, those are without Rod Cluster Control Assembly (RCCA), by insertion of a single RCCA (AO, M1, M2, MA, MB, MC, MD) and multiple insertion RCCA (MA + MB, MA + MB + MC, MA + MB + MC + MD, and MA + MB + MC + MD + M1). The maximum power factor of the fuel rods value in the fuel assembly assumedapproximately 1.406. The calculation results analysis showed that the 2-dimensional CITATION module of SRAC2006 code is accurate in AP1000 power distribution calculation without RCCA and with MA+MB RCCA insertion.The power peaking factor on the first operating cycle of the AP1000 core without RCCA, as well as with single and multiple RCCA are still below in the safety limit values (less then about 1.798). So in terms of thermal power generated by the fuel assembly, then it can be considered that the AP100 core at the first operating cycle is safe.

Antimatter Production for Near-Term Propulsion Applications

NASA Technical Reports Server (NTRS)

Gerrish, Harold P.; Schmidt, George R.

1999-01-01

This presentation discusses the use and potential of power generated from Proton-Antiproton Annihilation. The problem is that there is not enough production of anti-protons, and that the production methods are inefficient. The cost for 1 gram of antiprotons is estimated at 62.5 trillion dollars. Applications which require large quantities (i.e., about 1 kg) will require dramatic improvements in the efficiency of the production of the antiprotons. However, applications which involve small quantities (i.e., 1 to 10 micrograms may be practical with a relative expansion of capacities. There are four "conventional" antimatter propulsion concepts which are: (1) the solid core, (2) the gas core, (3) the plasma core, and the (4) beam core. These are compared in terms of specific impulse, propulsive energy utilization and vehicle structure/propellant mass ratio. Antimatter-catalyzed fusion propulsion is also evaluated. The improvements outlined in the presentation to the Fermilab production, and other sites. capability would result in worldwide capacity of several micrograms per year, by the middle of the next decade. The conclusions drawn are: (1) the Conventional antimatter propulsion IS not practical due to large p-bar requirement; (2) Antimatter-catalyzed systems can be reasonably considered this "solves" energy cost problem by employing substantially smaller quantities; (3) With current infrastructure, cost for 1 microgram of p-bars is $62.5 million, but with near-term improvements cost should drop; (4) Milligram-scale facility would require a $15 billion investment, but could produce 1 mg, at $0.1/kW-hr, for $6.25 million.

Unraveling Core Functional Microbiota in Traditional Solid-State Fermentation by High-Throughput Amplicons and Metatranscriptomics Sequencing

PubMed Central

Song, Zhewei; Du, Hai; Zhang, Yan; Xu, Yan

2017-01-01

Fermentation microbiota is specific microorganisms that generate different types of metabolites in many productions. In traditional solid-state fermentation, the structural composition and functional capacity of the core microbiota determine the quality and quantity of products. As a typical example of food fermentation, Chinese Maotai-flavor liquor production involves a complex of various microorganisms and a wide variety of metabolites. However, the microbial succession and functional shift of the core microbiota in this traditional food fermentation remain unclear. Here, high-throughput amplicons (16S rRNA gene amplicon sequencing and internal transcribed space amplicon sequencing) and metatranscriptomics sequencing technologies were combined to reveal the structure and function of the core microbiota in Chinese soy sauce aroma type liquor production. In addition, ultra-performance liquid chromatography and headspace-solid phase microextraction-gas chromatography-mass spectrometry were employed to provide qualitative and quantitative analysis of the major flavor metabolites. A total of 10 fungal and 11 bacterial genera were identified as the core microbiota. In addition, metatranscriptomic analysis revealed pyruvate metabolism in yeasts (genera Pichia, Schizosaccharomyces, Saccharomyces, and Zygosaccharomyces) and lactic acid bacteria (genus Lactobacillus) classified into two stages in the production of flavor components. Stage I involved high-level alcohol (ethanol) production, with the genus Schizosaccharomyces serving as the core functional microorganism. Stage II involved high-level acid (lactic acid and acetic acid) production, with the genus Lactobacillus serving as the core functional microorganism. The functional shift from the genus Schizosaccharomyces to the genus Lactobacillus drives flavor component conversion from alcohol (ethanol) to acid (lactic acid and acetic acid) in Chinese Maotai-flavor liquor production. Our findings provide insight into the effects of the core functional microbiota in soy sauce aroma type liquor production and the characteristics of the fermentation microbiota under different environmental conditions. PMID:28769888

Early Stage of Origin of Earth (interval after Emergence of Sun, Formation of Liquid Core, Formation of Solid Core)

NASA Astrophysics Data System (ADS)

Pechernikova, G. V.; Sergeev, V. N.

2017-05-01

Gravitational collapse of interstellar molecular cloud fragment has led to the formation of the Sun and its surrounding protoplanetary disk, consisting of 5 × 10^5 dust and gas. The collapse continued (1 years. Age of solar system (about 4.57×10^9 years) determine by age calcium-aluminum inclusions (CAI) which are present at samples of some meteorites (chondrites). Subsidence of dust to the central plane of a protoplanetary disk has led to formation of a dust subdisk which as a result of gravitational instability has broken up to condensations. In the process of collisional evolution they turned into dense planetesimals from which the planets formed. The accounting of a role of large bodies in evolution of a protoplanetary swarm in the field of terrestrial planets has allowed to define times of formation of the massive bodies permitting their early differentiation at the expense of short-lived isotopes heating and impacts to the melting temperature of the depths. The total time of Earth's growth is estimated about 10^8 years. Hf geochronometer showed that the core of the Earth has existed for Using W about 3×10^7 Hf geohronometer years since the formation of the CAI. Thus data W point to the formation of the Earth's core during its accretion. The paleomagnetic data indicate the existence of Earth's magnetic field past 3.5×10^9 years. But the age of the solid core, estimated by heat flow at the core-mantle boundary is 1.7×10^9 (0.5 years). Measurements of the thermal conductivity of liquid iron under the conditions that exist in the Earth's core, indicate the absence of the need for a solid core of existence to support the work geodynamo, although electrical resistivity measurements yield the opposite result.

An investigation into moisture barrier film coating efficacy and its relevance to drug stability in solid dosage forms.

PubMed

Mwesigwa, Enosh; Basit, Abdul W

2016-01-30

Barrier coatings are frequently employed on solid oral dosage forms under the assumption that they prevent moisture sorption into tablet cores thereby averting premature degradation of moisture-sensitive active ingredients. However, the efficacy of moisture barrier coatings remains unproven and they may actually accelerate degradation. This study aimed to investigate the barrier performance of four coating systems following application onto a low hygroscopic tablet formulation containing aspirin as a model moisture sensitive drug. Tablets were prepared by direct compaction and coated with aqueous dispersions of Eudragit(®) L30 D-55, Eudragit(®) EPO, Opadry(®) AMB and Sepifilm(®) LP at the vendors' recommended weight gains. Moisture uptake was studied by dynamic vapor sorption at 0 and 75% RH (25°C). Accelerated stability studies were undertaken at 75% RH/25°C for 90 days and HPLC assay was used to determine aspirin content. Uncoated tablet cores equilibrated rapidly and took up very little water (0.09%). The mean water uptake for coated cores was higher than for the uncoated formulation and varied as follows: 0.19% (Eudragit(®) L30 D-55), 0.35% (Opadry(®) AMB), 0.49% (Sepifilm(®) LP) and 0.76% (Eudragit(®) EPO). The level of aspirin decreased in all the samples such that by the time the study was terminated, the mean aspirin recovered was as follows: uncoated cores 80.0%; Eudragit® L30 D-55 coated cores 78.8%; Opadry(®) AMB coated cores 76.2%, Sepifilm(®) LP coated cores 76.0% and Eudragit(®) EPO coated samples 66.5%. From these results, it is concluded that the efficacy of moisture barrier polymer coatings on low hygroscopic cores is limited, and application of these coatings can, instead, enhance drug degradation in solid dosage forms. Copyright © 2015 Elsevier B.V. All rights reserved.

Experimental implementation of fiber optic bundle array wide FOV free space optical communications receiver.

PubMed

Brown, Andrea M; Hahn, Daniel V; Brown, David M; Rolander, Nathan W; Bair, Chun-Huei; Sluz, Joseph E

2012-06-20

A gimbal-free wide field-of-regard (FOR) optical receiver has been built in a laboratory setting for proof-of-concept testing. Multiple datasets are presented that examine the overall FOR of the system and the receiver's ability to track and collect a signal from a moving source. The design is not intended to compete with traditional free space optical communication systems, but rather offer an alternative design that minimizes the number and complexity of mechanical components required at the surface of a small mobile platform. The receiver is composed of a micro-lens array and hexagonal bundles of large core optical fibers that route the optical signal to remote detectors and electronics. Each fiber in the bundle collects power from a distinct solid angle of space and a piezo-electric transducer is used to translate the micro-lens array and optimize coupling into a given fiber core in the bundle. The micro-lens to fiber bundle design is scalable, modular, and can be replicated in an array to increase aperture size.

The MVAD pump: motor stator core loss characterization.

PubMed

Mesa, Kelly J; Ferreira, Antonio; Castillo, Samir; Reyes, Carlos; Wolman, Justin; Casas, Fernando

2015-01-01

Investigation of the miniature ventricular assist device (MVAD) pump motor stator core loss behavior was conducted. During operation, the ferromagnetic core in the pump's motor is magnetized by alternating magnetic fields, which, in turn, create intrinsic energy losses in the core material; these losses are known as core losses. A core loss fixture and a method to characterize the magnetic behavior of the MVAD pump stator over a range of frequencies were developed. The MVAD pump motor design features a three phase brushless DC stator with ferromagnetic laminations and copper wire windings arranged in a six slot configuration. The stator's magnetic behavior is important because its core magnetic losses impact pump system efficiency. A system to measure the core loss of MVAD pump stators was developed using a custom core loss fixture consisting of 16 copper wire turns wound in a closed loop geometry bundle; the stator under test was then placed within this bundle. The instrumentation consisted of a signal generator, a power amplifier, and a power analyzer. Power analyzer parameters of current, voltage, and power were collected for several runs with a sinusoidal frequency sweep of 0 to 50 kHz; data were collected for the fixture with and without stators. The magnetic losses inherent to the fixture were characterized independently as a baseline presenting a flat frequency response. The core loss power measurements of individual stators yielded a characteristic bandpass frequency response morphology with a peak core loss found around 2.3 to 2.5 kHz. In conclusion, this method could be used to describe the transfer function of the stator's core magnetic behavior. It also has the potential to be used for future motor evaluation and for investigation of core loss performance variability between different stators during manufacturing operations. Investigational device. Limited by United States law to investigational use.

JAERI R & D on accelerator-based transmutation under OMEGA program

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

Takizuka, T.; Nishida, T.; Mizumoto, M.

1995-10-01

The overview of the Japanese long-term research and development program on nuclide partitioning and transmutation, called {open_quotes}OMEGA,{close_quotes} is presented. Under this national program, major R&D activities are being carried out at JAERI, PNC, and CRIEPI. Accelerator-based transmutation study at JAERI is focused on a dedicated transmutor with a subcritical actinide-fueled subcritical core coupled with a spallation target driven by a high intensity proton accelerator. Two types of system concept, solid system and molten-salt system, are discussed. The solid system consists of sodium-cooled tungsten target and metallic actinide fuel. The molten-salt system is fueled with molten actinide chloride that acts alsomore » as a target material. The proposed plant transmutes about 250 kg of minor actinide per year, and generates enough electricity to power its own accelerator. JAERI is proposing the development of an intense proton linear accelerator ETA with 1.5 GeV-10 mA beam for engineering tests of accelerator-based transmutation. Recent achievements in the accelerator development are described.« less

40 CFR 256.22 - Recommendations for State regulatory powers.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Recommendations for State regulatory powers. 256.22 Section 256.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Solid Waste...

40 CFR 256.22 - Recommendations for State regulatory powers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Recommendations for State regulatory powers. 256.22 Section 256.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Solid Waste...

40 CFR 256.21 - Requirements for State regulatory powers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Requirements for State regulatory powers. 256.21 Section 256.21 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Solid Waste...

40 CFR 256.21 - Requirements for State regulatory powers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Requirements for State regulatory powers. 256.21 Section 256.21 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Solid Waste...

40 CFR 256.21 - Requirements for State regulatory powers.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Requirements for State regulatory powers. 256.21 Section 256.21 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Solid Waste...

40 CFR 256.22 - Recommendations for State regulatory powers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Recommendations for State regulatory powers. 256.22 Section 256.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR DEVELOPMENT AND IMPLEMENTATION OF STATE SOLID WASTE MANAGEMENT PLANS Solid Waste...

Combustion of metal agglomerates in a solid rocket core flow

NASA Astrophysics Data System (ADS)

Maggi, Filippo; Dossi, Stefano; DeLuca, Luigi T.

2013-12-01

The need for access to space may require the use of solid propellants. High thrust and density are appealing features for different applications, spanning from boosting phase to other service applications (separation, de-orbiting, orbit insertion). Aluminum is widely used as a fuel in composite solid rocket motors because metal oxidation increases enthalpy release in combustion chamber and grants higher specific impulse. Combustion process of metal particles is complex and involves aggregation, agglomeration and evolution of reacting particulate inside the core flow of the rocket. It is always stated that residence time should be enough in order to grant complete metal oxidation but agglomerate initial size, rocket grain geometry, burning rate, and other factors have to be reconsidered. New space missions may not require large rocket systems and metal combustion efficiency becomes potentially a key issue to understand whether solid propulsion embodies a viable solution or liquid/hybrid systems are better. A simple model for metal combustion is set up in this paper. Metal particles are represented as single drops trailed by the core flow and reacted according to Beckstead's model. The fluid dynamics is inviscid, incompressible, 1D. The paper presents parametric computations on ideal single-size particles as well as on experimental agglomerate populations as a function of operating rocket conditions and geometries.

Solid-State Cloud Radar System (CRS) Upgrade and Deployment

NASA Technical Reports Server (NTRS)

McLinden, Matt; Heymsfield, Gerald; Li, Lihua; Racette, Paul; Coon, Michael; Venkatesh, Vijay

2015-01-01

The recent decade has brought rapid development in solid-state power amplifier (SSPA) technology. This has enabled the use of solid-state precipitation radar in place of high-power and high-voltage systems such as those that use Klystron or Magnetron transmitters. The NASA Goddard Space Flight Center has recently completed a comprehensive redesign of the 94 gigahertz Cloud Radar System (CRS) to incorporate a solid-state transmitter. It is the first cloud radar to achieve sensitivity comparable to that of a high-voltage transmitter using solid-state. The NASA Goddard Space Flight Center's Cloud Radar System (CRS) is a 94 gigahertz Doppler radar that flies on the NASA ER-2 high-altitude aircraft. The upgraded CRS system utilizes a state-of-the-art solid-state 94 gigahertz power amplifier with a peak transmit power of 30 watts. The modernized CRS system is detailed here with data results from its deployment during the 2014 Integrated Precipitation and Hydrology Experiment (IPHEX).

Solid oxide fuel cell having monolithic core

DOEpatents

Ackerman, John P.; Young, John E.

1984-01-01

A solid oxide fuel cell for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support. Instead, the core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material therebetween, and each interconnect wall consists of thin layers of the cathode and anode materials sandwiching a thin layer of interconnect material therebetween. The electrolyte walls are arranged and backfolded between adjacent interconnect walls operable to define a plurality of core passageways alternately arranged where the inside faces thereof have only the anode material or only the cathode material exposed. Means direct the fuel to the anode-exposed core passageways and means direct the oxidant to the cathode-exposed core passageway; and means also direct the galvanic output to an exterior circuit. Each layer of the electrolyte and interconnect materials is of the order of 0.002-0.01 cm thick; and each layer of the cathode and anode materials is of the order of 0.002-0.05 cm thick.

Tailoring gadolinium-doped ceria-based solid oxide fuel cells to achieve 2 W cm(-2) at 550 °C.

PubMed

Lee, Jin Goo; Park, Jeong Ho; Shul, Yong Gun

2014-06-04

Low-temperature operation is necessary for next-generation solid oxide fuel cells due to the wide variety of their applications. However, significant increases in the fuel cell losses appear in the low-temperature solid oxide fuel cells, which reduce the cell performance. To overcome this problem, here we report Gd0.1Ce0.9O1.95-based low-temperature solid oxide fuel cells with nanocomposite anode functional layers, thin electrolytes and core/shell fibre-structured Ba0.5Sr0.5Co0.8Fe0.2O3-δ-Gd0.1Ce0.9O1.95 cathodes. In particular, the report describes the use of the advanced electrospinning and Pechini process in the preparation of the core/shell-fibre-structured cathodes. The fuel cells show a very high performance of 2 W cm(-2) at 550 °C in hydrogen, and are stable for 300 h even under the high current density of 1 A cm(-2). Hence, the results suggest that stable and high-performance solid oxide fuel cells at low temperatures can be achieved by modifying the microstructures of solid oxide fuel cell components.

Gas core reactors for actinide transmutation and breeder applications

NASA Technical Reports Server (NTRS)

Clement, J. D.; Rust, J. H.

1978-01-01

This work consists of design power plant studies for four types of reactor systems: uranium plasma core breeder, uranium plasma core actinide transmuter, UF6 breeder and UF6 actinide transmuter. The plasma core systems can be coupled to MHD generators to obtain high efficiency electrical power generation. A 1074 MWt UF6 breeder reactor was designed with a breeding ratio of 1.002 to guard against diversion of fuel. Using molten salt technology and a superheated steam cycle, an efficiency of 39.2% was obtained for the plant and the U233 inventory in the core and heat exchangers was limited to 105 Kg. It was found that the UF6 reactor can produce high fluxes (10 to the 14th power n/sq cm-sec) necessary for efficient burnup of actinide. However, the buildup of fissile isotopes posed severe heat transfer problems. Therefore, the flux in the actinide region must be decreased with time. Consequently, only beginning-of-life conditions were considered for the power plant design. A 577 MWt UF6 actinide transmutation reactor power plant was designed to operate with 39.3% efficiency and 102 Kg of U233 in the core and heat exchanger for beginning-of-life conditions.

Integrating Magnetics for On-Chip Power: A Perspective

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

Sullivan, CR; Harburg, DV; Qiu, JZ

Integration of efficient power converters requires technology for efficient, high-power on-chip inductors and transformers. Increases in switching frequency, facilitated by advances in circuit designs and silicon or wide-bandgap semiconductors, can enable miniaturization, but only if the magnetics technology works well at the higher frequencies. Technologies, geometries, and scaling of air-core and magnetic-core inductors and transformers are examined, and their potential for integration is discussed. Air-core inductors can use simpler fabrication, and increasing frequency can always be used to decrease their size, but magnetic cores can decrease the required thickness without requiring as high a frequency.

Power supply with air core transformer and seperated power supplies for high dynamic range

NASA Technical Reports Server (NTRS)

Orient, Otto (Inventor); Chutjian, Ara (Inventor); Aalami, Dean (Inventor); Darrach, Murray (Inventor)

2001-01-01

A power supply for a quadrupole mass spectrometer which operates using an RF signal. The RF signal is controllable via a feedback loop. The feedback loop is from the output, through a comparator, and compared to a digital signal. An air core transformer is used to minimize the weight. The air core transformer is driven via two out of phase sawtooth signals which drive opposite ends of the transformer.

Dye-sensitized solar cells employing a SnO2-TiO2 core-shell structure made by atomic layer deposition.

PubMed

Karlsson, Martin; Jõgi, Indrek; Eriksson, Susanna K; Rensmo, Håkan; Boman, Mats; Boschloo, Gerrit; Hagfeldt, Anders

2013-01-01

This paper describes the synthesis and characterization of core-shell structures, based on SnO2 and TiO2, for use in dye-sensitized solar cells (DSC). Atomic layer deposition is employed to control and vary the thickness of the TiO2 shell. Increasing the TiO2 shell thickness to 2 nm improved the device performance of liquid electrolyte-based DSC from 0.7% to 3.5%. The increase in efficiency originates from a higher open-circuit potential and a higher short-circuit current, as well as from an improvement in the electron lifetime. SnO2-TiO2 core-shell DSC devices retain their photovoltage in darkness for longer than 500 seconds, demonstrating that the electrons are contained in the core material. Finally core-shell structures were used for solid-state DSC applications using the hole transporting material 2,2',7,7',-tetrakis(N, N-di-p-methoxyphenyl-amine)-9,9',-spirofluorene. Similar improvements in device performance were obtained for solid-state DSC devices.

Effect of Solid-State Power-Converter Harmonics on Electric-Power-Supply Systems

DOT National Transportation Integrated Search

1973-03-01

The United States utility industry has not set suitable standards, other than TIF (Telephone Interference Factor), for controlling the design of solid-state wayside and on-board power-conversion equipment, to limit the harmonic currents and voltages ...

Palaeointensity, core thermal conductivity and the unknown age of the inner core

NASA Astrophysics Data System (ADS)

Smirnov, Aleksey V.; Tarduno, John A.; Kulakov, Evgeniy V.; McEnroe, Suzanne A.; Bono, Richard K.

2016-05-01

Data on the evolution of Earth's magnetic field intensity are important for understanding the geodynamo and planetary evolution. However, the paleomagnetic record in rocks may be adversely affected by many physical processes, which must be taken into account when analysing the palaeointensity database. This is especially important in the light of an ongoing debate regarding core thermal conductivity values, and how these relate to the Precambrian geodynamo. Here, we demonstrate that several data sets in the Precambrian palaeointensity database overestimate the true paleofield strength due to the presence of non-ideal carriers of palaeointensity signals and/or viscous re-magnetizations. When the palaeointensity overestimates are removed, the Precambrian database does not indicate a robust change in geomagnetic field intensity during the Mesoproterozoic. These findings call into question the recent claim that the solid inner core formed in the Mesoproterozoic, hence constraining the thermal conductivity in the core to `moderate' values. Instead, our analyses indicate that the presently available palaeointensity data are insufficient in number and quality to constrain the timing of solid inner core formation, or the outstanding problem of core thermal conductivity. Very young or very old inner core ages (and attendant high or low core thermal conductivity values) are consistent with the presently known history of Earth's field strength. More promising available data sets that reflect long-term core structure are geomagnetic reversal rate and field morphology. The latter suggests changes that may reflect differences in Archean to Proterozoic core stratification, whereas the former suggest an interval of geodynamo hyperactivity at ca. 550 Ma.

Comparison of Histologic Core Portions Acquired from a Core Biopsy Needle and a Conventional Needle in Solid Mass Lesions: A Prospective Randomized Trial.

PubMed

Lee, Ban Seok; Cho, Chang-Min; Jung, Min Kyu; Jang, Jung Sik; Bae, Han Ik

2017-07-15

The superiority of endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) over EUS-guided fine needle aspiration (EUS-FNA) remains controversial. Given the lack of studies analyzing histologic specimens acquired from EUS-FNB or EUS-FNA, we compared the proportion of the histologic core obtained from both techniques. A total of 58 consecutive patients with solid mass lesions were enrolled and randomly assigned to the EUS-FNA or EUS-FNB groups. The opposite needle was used after the failure of core tissue acquisition using the initial needle with up to three passes. Using computerized analyses of the scanned histologic slide, the overall area and the area of the histologic core portion in specimens obtained by the two techniques were compared. No significant differences were identified between the two groups with respect to demographic and clinical characteristics. Fewer needle passes were required to obtain core specimens in the FNB group (p<0.001). There were no differences in the proportion of histologic core (11.8%±19.5% vs 8.0%±11.1%, p=0.376) or in the diagnostic accuracy (80.6% vs 81.5%, p=0.935) between two groups. The proportion of histologic core and the diagnostic accuracy were comparable between the FNB and FNA groups. However, fewer needle passes were required to establish an accurate diagnosis in EUS-FNB.

Lithium sulfide compositions for battery electrolyte and battery electrode coatings

DOEpatents

Liang, Chengdu; Liu, Zengcai; Fu, Wunjun; Lin, Zhan; Dudney, Nancy J; Howe, Jane Y; Rondinone, Adam J

2013-12-03

Methods of forming lithium-containing electrolytes are provided using wet chemical synthesis. In some examples, the lithium containing electroytes are composed of .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7. The solid electrolyte may be a core shell material. In one embodiment, the core shell material includes a core of lithium sulfide (Li.sub.2S), a first shell of .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7, and a second shell including one or .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7 and carbon. The lithium containing electrolytes may be incorporated into wet cell batteries or solid state batteries.

Lithium sulfide compositions for battery electrolyte and battery electrode coatings

DOEpatents

Liang, Chengdu; Liu, Zengcai; Fu, Wujun; Lin, Zhan; Dudney, Nancy J; Howe, Jane Y; Rondinone, Adam J

2014-10-28

Method of forming lithium-containing electrolytes are provided using wet chemical synthesis. In some examples, the lithium containing electrolytes are composed of .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7. The solid electrolyte may be a core shell material. In one embodiment, the core shell material includes a core of lithium sulfide (Li.sub.2S), a first shell of .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7, and a second shell including one of .beta.-Li.sub.3PS.sub.4 or Li.sub.4P.sub.2S.sub.7 and carbon. The lithium containing electrolytes may be incorporated into wet cell batteries or solid state batteries.

Power generation plant integrating concentrated solar power receiver and pressurized heat exchanger

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

Sakadjian, Bartev B; Flynn, Thomas J; Hu, Shengteng

A power plant includes a solar receiver heating solid particles, a standpipe receiving solid particles from the solar receiver, a pressurized heat exchanger heating working fluid by heat transfer through direct contact with heated solid particles flowing out of the bottom of the standpipe, and a flow path for solid particles from the bottom of the standpipe into the pressurized heat exchanger that is sealed by a pressure P produced at the bottom of the standpipe by a column of heated solid particles of height H. The flow path may include a silo or surge tank comprising a pressure vesselmore » connected to the bottom of the standpipe, and a non-mechanical valve. The power plant may further include a turbine driven by heated working fluid discharged from the pressurized heat exchanger, and a compressor driven by the turbine.« less

Quench-age method for the fabrication of niobium-aluminum superconductors

DOEpatents

Pickus, Milton R.; Ciardella, Robert L.

1978-01-01

A flexible Nb.sub.3 Al superconducting wire is fabricated from a niobium-aluminum composite wire by heating to form a solid solution which is retained at room temperature as a metastable solid solution by quenching. The metastable solid solution is then transformed to the stable superconducting A-15 phase by low temperature aging. The transformation induced by aging can be controlled to yield either a multifilamentary or a solid A-15 core surrounded by ductile niobium.

Intelligent switches of integrated lightwave circuits with core telecommunication functions

NASA Astrophysics Data System (ADS)

Izhaky, Nahum; Duer, Reuven; Berns, Neil; Tal, Eran; Vinikman, Shirly; Schoenwald, Jeffrey S.; Shani, Yosi

2001-05-01

We present a brief overview of a promising switching technology based on Silica on Silicon thermo-optic integrated circuits. This is basically a 2D solid-state optical device capable of non-blocking switching operation. Except of its excellent performance (insertion loss<5dB, switching time<2ms...), the switch enables additional important build-in functionalities. It enables single-to- single channel switching and single-to-multiple channel multicasting/broadcasting. In addition, it has the capability of channel weighting and variable output power control (attenuation), for instance, to equalize signal levels and compensate for unbalanced different optical input powers, or to equalize unbalanced EDFA gain curve. We examine the market segments appropriate for the switch size and technology, followed by a discussion of the basic features of the technology. The discussion is focused on important requirements from the switch and the technology (e.g., insertion loss, power consumption, channel isolation, extinction ratio, switching time, and heat dissipation). The mechanical design is also considered. It must take into account integration of optical fiber, optical planar wafer, analog electronics and digital microprocessor controls, embedded software, and heating power dissipation. The Lynx Photon.8x8 switch is compared to competing technologies, in terms of typical market performance requirements.

[The design of all solid-state tunable pulsed Ti:sapphire laser system].

PubMed

Chen, Zhe; Ku, Geng; Wan, Junchao; Wang, Wei; Zhou, Chuanqing

2013-05-01

This paper presented a design of broadly all solid-state tunable pulsed Ti:sapphire laser with high power and stable performance. The laser was pumped by custom-made Nd:YAG laser which had water cooling system and amplified by two stage amplifier. The method accomplished tunable output of all solid-state tunable pulsed Ti:sapphire laser by modifying the reflection angle of the back mirror. We investigated the relationship between the power of the pumping laser and the all solid-state tunable pulsed Ti: sapphire laser by changing the power of the pumping source.

High power RF solid state power amplifier system

NASA Technical Reports Server (NTRS)

Sims, III, William Herbert (Inventor); Chavers, Donald Gregory (Inventor); Richeson, James J. (Inventor)

2011-01-01

A high power, high frequency, solid state power amplifier system includes a plurality of input multiple port splitters for receiving a high-frequency input and for dividing the input into a plurality of outputs and a plurality of solid state amplifier units. Each amplifier unit includes a plurality of amplifiers, and each amplifier is individually connected to one of the outputs of multiport splitters and produces a corresponding amplified output. A plurality of multiport combiners combine the amplified outputs of the amplifiers of each of the amplifier units to a combined output. Automatic level control protection circuitry protects the amplifiers and maintains a substantial constant amplifier power output.

Solid-state resistor for pulsed power machines

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

Stoltzfus, Brian; Savage, Mark E.; Hutsel, Brian Thomas

2016-12-06

A flexible solid-state resistor comprises a string of ceramic resistors that can be used to charge the capacitors of a linear transformer driver (LTD) used in a pulsed power machine. The solid-state resistor is able to absorb the energy of a switch prefire, thereby limiting LTD cavity damage, yet has a sufficiently low RC charge time to allow the capacitor to be recharged without disrupting the operation of the pulsed power machine.

Models of the Earth's Core.

PubMed

Stevenson, D J

1981-11-06

Combined inferences from seismology, high-pressure experiment and theory, geomagnetism, fluid dynamics, and current views of terrestrial planetary evolution lead to models of the earth's core with the following properties. Core formation was contemporaneous with earth accretion; the core is not in chemical equilibrium with the mantle; the outer core is a fluid iron alloy containing significant quantities of lighter elements and is probably almost adiabatic and compositionally uniform; the more iron-rich inner solid core is a consequence of partial freezing of the outer core, and the energy release from this process sustains the earth's magnetic field; and the thermodynamic properties of the core are well constrained by the application of liquid-state theory to seismic and laboratory data.

Power monitoring in space nuclear reactors using silicon carbide radiation detectors

NASA Technical Reports Server (NTRS)

Ruddy, Frank H.; Patel, Jagdish U.; Williams, John G.

2005-01-01

Space reactor power monitors based on silicon carbide (SiC) semiconductor neutron detectors are proposed. Detection of fast leakage neutrons using SiC detectors in ex-core locations could be used to determine reactor power: Neutron fluxes, gamma-ray dose rates and ambient temperatures have been calculated as a function of distance from the reactor core, and the feasibility of power monitoring with SiC detectors has been evaluated at several ex-core locations. Arrays of SiC diodes can be configured to provide the required count rates to monitor reactor power from startup to full power Due to their resistance to temperature and the effects of neutron and gamma-ray exposure, SiC detectors can be expected to provide power monitoring information for the fill mission of a space reactor.

To enhance the efficiency of a power supply circuit by the use of Fe-P-B-Nb-type ultralow loss glassy metal core

NASA Astrophysics Data System (ADS)

Matsumoto, H.; Urata, A.; Yamada, Y.; Makino, A.

2009-04-01

The inductor in a power supply is required to be capable of dealing satisfactorily with the high-current supply and to improve the power loss characteristic. A novel glassy metal powder with a chemical composition Fe77P7B13Nb3 features both a high saturated magnetic flux density of 1.3 T and a low coercive force of 2.0 A/m, which has a stable amorphous structure suitable for glassy metal composite cores. Hence there is no magnetic saturation even under a high-current supply, and it is confirmed to have significantly low magnetic loss resulting from the low coercive force. As a result of using the glassy metal alloy Fe77P7B13Nb3 powder in an inductor core, we have achieved improvement in power supply efficiency by up to roughly 2.0%. Moreover, the reduction in the standby power requirement by the improvement in the power supply efficiency in the low load current case, where the core loss occupies a high ratio in the entire loss, can be expected. Additionally, heat generation in a core is suppressed by using the low loss powder, and it becomes easy to design a temperature rise in the entire power supply circuit.

Low Power Consumption Design and Fabrication of Thin Film Core for Micro Fluxgate.

PubMed

Lv, Hui; Liu, Shibin

2016-03-01

The soft magnetic characteristic of core is a critical factor to performance of the micro fluxgate. Porous thin film core can be effectively used to decrease the value of saturation magnetic field strength (H(s)) and improve soft magnetic behavior. It is conducive to impelling the micro fluxgate toward the direction of low power consumption. In this work, negative photoresist is used to fabricate a porous core by MEMS technology. Through the processes of ultraviolet-lithography, the porous pattern transfer from the mask to the microstructure on silicon substrate. The experiment result complies with the anticipation and indicates that this MEMS technique can be applied to improve the characteristic of thin film core and decrease power consumption of fluxgate sensor.

Energy Efficient Real-Time Scheduling Using DPM on Mobile Sensors with a Uniform Multi-Cores

PubMed Central

Kim, Youngmin; Lee, Chan-Gun

2017-01-01

In wireless sensor networks (WSNs), sensor nodes are deployed for collecting and analyzing data. These nodes use limited energy batteries for easy deployment and low cost. The use of limited energy batteries is closely related to the lifetime of the sensor nodes when using wireless sensor networks. Efficient-energy management is important to extending the lifetime of the sensor nodes. Most effort for improving power efficiency in tiny sensor nodes has focused mainly on reducing the power consumed during data transmission. However, recent emergence of sensor nodes equipped with multi-cores strongly requires attention to be given to the problem of reducing power consumption in multi-cores. In this paper, we propose an energy efficient scheduling method for sensor nodes supporting a uniform multi-cores. We extend the proposed T-Ler plane based scheduling for global optimal scheduling of a uniform multi-cores and multi-processors to enable power management using dynamic power management. In the proposed approach, processor selection for a scheduling and mapping method between the tasks and processors is proposed to efficiently utilize dynamic power management. Experiments show the effectiveness of the proposed approach compared to other existing methods. PMID:29240695

Tuning the synthesis of platinum-copper nanoparticles with a hollow core and porous shell for the selective hydrogenation of furfural to furfuryl alcohol

NASA Astrophysics Data System (ADS)

Huang, Shuangshuang; Yang, Nating; Wang, Shibin; Sun, Yuhan; Zhu, Yan

2016-07-01

Pt-Cu nanoparticles constructed with a hollow core and porous shell have been synthesized in which Pt-Cu cages with multiporous outermost shells are formed at the initial stage and then the Pt and Cu atoms in solution continuously fed these hollow-core of cages by passing through the porous tunnels of the outermost shells, finally leading to the formation of hollow structures with different sizes. Furthermore, these hollow-core Pt-Cu nanoparticles are more effective than the solid-core Pt-Cu nanoparticles for the catalytic hydrogenation of furfural toward furfuryl alcohol. The former can achieve almost 100% conversion of furfural with 100% selectivity toward the alcohol.Pt-Cu nanoparticles constructed with a hollow core and porous shell have been synthesized in which Pt-Cu cages with multiporous outermost shells are formed at the initial stage and then the Pt and Cu atoms in solution continuously fed these hollow-core of cages by passing through the porous tunnels of the outermost shells, finally leading to the formation of hollow structures with different sizes. Furthermore, these hollow-core Pt-Cu nanoparticles are more effective than the solid-core Pt-Cu nanoparticles for the catalytic hydrogenation of furfural toward furfuryl alcohol. The former can achieve almost 100% conversion of furfural with 100% selectivity toward the alcohol. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr03894h

New Mechanism of Extractive Electrospray Ionization Mass Spectrometry for Heterogeneous Solid Particles.

PubMed

Kumbhani, S; Longin, T; Wingen, L M; Kidd, C; Perraud, V; Finlayson-Pitts, B J

2018-02-06

Real-time in situ mass spectrometry analysis of airborne particles is important in several applications, including exposure studies in ambient air, industrial settings, and assessing impacts on visibility and climate. However, obtaining molecular and 3D structural information is more challenging, especially for heterogeneous solid or semisolid particles. We report a study of extractive electrospray ionization mass spectrometry (EESI-MS) for the analysis of solid particles with an organic coating. The goal is to elucidate how much of the overall particle content is sampled, and determine the sensitivity of this technique to the surface layers. It is shown that, for NaNO 3 particles coated with glutaric acid (GA), very little of the solid NaNO 3 core is sampled compared to the GA coating, whereas for GA particles coated with malonic acid (MA), significant signals from both the MA coating and the GA core are observed. However, conventional ESI-MS of the same samples collected on a Teflon filter (and then extracted) detects much more core material compared to EESI-MS in both cases. These results show that, for the experimental conditions used here, EESI-MS does not sample the entire particle but, instead, is more sensitive to surface layers. Separate experiments on single-component particles of NaNO 3 , GA, or citric acid show that there must be a kinetics limitation to dissolution that is important in determining EESI-MS sensitivity. We propose a new mechanism of EESI solvent droplet interaction with solid particles that is consistent with the experimental observations. In conjunction with previous EESI-MS studies of organic particles, these results suggest that EESI does not necessarily sample the entire particle when solid, and that not only solubility but also surface energies and the kinetics of dissolution play an important role.

Experimental Study on Scale-Up of Solid-Liquid Stirred Tank with an Intermig Impeller

NASA Astrophysics Data System (ADS)

Zhao, Hongliang; Zhao, Xing; Zhang, Lifeng; Yin, Pan

2017-02-01

The scale-up of a solid-liquid stirred tank with an Intermig impeller was characterized via experiments. Solid concentration, impeller just-off-bottom speed and power consumption were measured in stirred tanks of different scales. The scale-up criteria for achieving the same effect of solid suspension in small-scale and large-scale vessels were evaluated. The solids distribution improves if the operating conditions are held constant as the tank is scaled-up. The results of impeller just-off-bottom speed gave X = 0.868 in the scale-up relationship ND X = constant. Based on this criterion, the stirring power per unit volume obviously decreased at N = N js, and the power number ( N P) was approximately equal to 0.3 when the solids are uniformly distributed in the vessels.

Combining high power diode lasers using fiber bundles for beam delivery in optoacoustic endoscopy applications

NASA Astrophysics Data System (ADS)

Gawali, Sandeep Babu; Leggio, Luca; Sánchez, Miguel; Rodríguez, Sergio; Dadrasnia, Ehsan; Gallego, Daniel C.; Lamela, Horacio

2016-05-01

Optoacoustic (OA) effect refers to the generation of the acoustic waves due to absorption of light energy in a biological tissue. The incident laser pulse is absorbed by the tissue, resulting in the generation of ultrasound that is typically detected by a piezoelectric detector. Compared to other techniques, the advantage of OA imaging (OAI) technique consists in combining the high resolution of ultrasound technique with the high contrast of optical imaging. Generally, Nd:YAG and OPO systems are used for the generation of OA waves but their use in clinical environment is limited for many aspects. On the other hand, high-power diode lasers (HPDLs) emerge as potential alternative. However, the power of HPDLs is still relatively low compared to solid-state lasers. We show a side-by-side combination of several HPDLs in an optical fiber bundle to increase the amount of power for OA applications. Initially, we combine the output optical power of several HPDLs at 905 nm using two 7 to 1 round optical fiber bundles featuring a 675 μm and 1.2 mm bundle aperture. In a second step, we couple the output light of these fiber bundles to a 600 μm core diameter endoscopic fiber, reporting the corresponding coupling efficiencies. The fiber bundles with reasonable small diameter are likely to be used for providing sufficient light energy to potential OA endoscopy (OAE) applications.

Design Study of Modular Nuclear Power Plant with Small Long Life Gas Cooled Fast Reactors Utilizing MOX Fuel

NASA Astrophysics Data System (ADS)

Ilham, Muhammad; Su'ud, Zaki

2017-01-01

Growing energy needed due to increasing of the world’s population encourages development of technology and science of nuclear power plant in its safety and security. In this research, it will be explained about design study of modular fast reactor with helium gas cooling (GCFR) small long life reactor, which can be operated over 20 years. It had been conducted about neutronic design GCFR with Mixed Oxide (UO2-PuO2) fuel in range of 100-200 MWth NPPs of power and 50-60% of fuel fraction variation with cylindrical pin cell and cylindrical balance of reactor core geometry. Calculation method used SRAC-CITATION code. The obtained results are the effective multiplication factor and density value of core reactor power (with geometry optimalization) to obtain optimum design core reactor power, whereas the obtained of optimum core reactor power is 200 MWth with 55% of fuel fraction and 9-13% of percentages.

Constraining Mercury's interior structure with geodesy data and its present thermal state

NASA Astrophysics Data System (ADS)

Rivoldini, Attilio; Van Hoolst, Tim; Noack, Lena

2015-04-01

Recent measurements of Mercury's spin state and gravitational field supplemented by the assumption that the planet's core is made of iron and sulfur give strong constraints on its interior structure. In particular, they allow a precise determination of Mercury's core size and average mantle density. Present geodesy data do, however, almost not constrain the size of the inner core. Interior structure models with a fully molten liquid core as well as models with an inner core almost as large as the core agree with the observations. Additionally, the observed internally generated magnetic field of Mercury does not preclude the absence of an inner core, since remelting of iron snow inside the core could produce a sufficient buoyancy flux to drive magnetic field generation by compositional convection. Although sulfur is ubiquitously invoked as being the principal candidate light element in terrestrial planet's cores its abundance in the core depends on the redox conditions during planetary formation. Remote sensing data of Mercury's surface by MESSENGER indicate that Mercury formed under reducing conditions. As a consequence, substantial amounts of other light elements like for example silicon and carbon could be present together with sulfur inside Mercury's core. Compared to sulfur, which does almost not partition into solid iron at Mercury's core conditions, silicon partitions almost equally well between solid and liquid iron whereas a few percent of carbon can partition into solid iron. Therefore, compared to a pure iron-sulfur core, if silicon and carbon are present in the core the density jump at the inner-core outer-core boundary could be smaller and induce a large enough change in the inner-core flattening to alter Mercury's libration amplitude. Moreover, the presence of carbon together with sulfur further reduces the core solidus temperature, potentially delaying the onset of inner core formation. Finally, if both silicon and sulfur are present in sufficient quantities a thin layer much enriched in sulfur and depleted in silicon could form at the top of the core as a consequence of a large immiscibility region in liquid Fe-S-Si at Mercury's core conditions. The present radius of an inner core depends mainly on Mercury's thermal state and concentration of light elements inside the core. Because of the secular cooling of the planet, at a time in Mercury's evolution the temperature inside the core drops below the core liquidus temperature somewhere in the core, which can lead to the formation of an inner core and to the global contraction of the planet. The amount of contraction depends mainly on the temperature decrease, on the thermal expansion of the materials inside the planet, on the volume of crystallized iron-rich core liquid, and on the volume of crystallized crust. In this study we use geodesy data (88 day libration amplitude, polar moment of inertia, and tidal Love number), the recent estimate about the radial contraction of Mercury, and thermo-chemical evolution calculations taking into account the formation of the crust, a growing inner core, and modeling the formation of iron-rich snow in the core in order to improve our knowledge about Mercury's inner core radius and thermal state. Since data from remote sensing of Mercury's surface indicate that Mercury formed under reducing conditions we consider models that have sulfur, silicon, and carbon as light elements inside their core.

Formative Assessment Probes: Is It a Solid? Claim Cards and Argumentation

ERIC Educational Resources Information Center

Keeley, Page

2013-01-01

A "Framework for K-12 Science Education"'s disciplinary core idea PS1.A states that students should know by the end of grade 2 that different kinds of matter exist and many of them can be solid or liquid, depending on temperature (NRC 2012). By the end of grade 8, they describe solids, liquids, and gases by the arrangement and…

Optical properties of solid-core photonic crystal fibers filled with nonlinear absorbers.

PubMed

Butler, James J; Bowcock, Alec S; Sueoka, Stacey R; Montgomery, Steven R; Flom, Steven R; Friebele, E Joseph; Wright, Barbara M; Peele, John R; Pong, Richard G S; Shirk, James S; Hu, Jonathan; Menyuk, Curtis R; Taunay, T F

2013-09-09

A theoretical and experimental investigation of the transmission of solid-core photonic crystal fibers (PCFs) filled with nonlinear absorbers shows a sharp change in the threshold for optical limiting and in leakage loss as the refractive index of the material in the holes approaches that of the glass matrix. Theoretical calculations of the mode profiles and leakage loss of the PCF are in agreement with experimental results and indicate that the change in limiting response is due to the interaction of the evanescent field of the guided mode with the nonlinear absorbers in the holes.

Core power and decay time limits for a disabled LOFT ECCS

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

Atkinson, S.A.

1978-01-09

An analysis was done to determine at what LOFT total core power (nuclear plus decay power) the ECCS could be inoperable. The criteria used for the analysis was that the maximum fuel clad temperature should not exceed 1650/sup 0/F given a loss of coolant. Calculations for natural convection cooling of the fuel by air with an inlet temperature of 580/sup 0/F determined that the limiting core power is 25 kW (discounted by 15 percent to 20 percent for potential uncertainties). Shutdown times are listed for when the LOFT ECCS can be safely bypassed or disabled.

The Earth's Core.

ERIC Educational Resources Information Center

Jeanloz, Raymond

1983-01-01

The nature of the earth's core is described. Indirect evidence (such as that determined from seismological data) indicates that it is an iron alloy, solid toward its center but otherwise liquid. Evidence also suggests that it is the turbulent flow of the liquid that generates the earth's magnetic field. (JN)

Solid-phase microextraction may catalize hydrogenation when using hydrogen as carrier in gas chromatography.

PubMed

Fiorini, D; Boarelli, M C

2016-07-01

When hydrogen is used as carrier gas, carbon-carbon double bonds may be hydrogenated in the hot gas chromatograph (GC) injector if introduced by solid-phase microextraction (SPME). SPME fibers coated with polydimethylsiloxane (PDMS)/carboxen/divinylbenzene (DVB), PDMS/carboxen, polyacrylate, PDMS/DVB and PDMS on fused silica, stableflex or metal alloy core have been tested with fatty acid methyl esters (FAMEs) from olive oil. Using coatings containing DVB, hydrogenation took place with high conversion rates (82.0-92.9%) independently of the core material. With all fibers having a metal core, hydrogenation was observed to a certain extent (27.4-85.3%). PDMS, PDMS/carboxen and polyacrylate coated fibers with a fused silica or stableflex core resulted in negligible hydrogenation (0.2-2.5%). The occurrence of hydrogenation was confirmed also with other substances containing carbon-carbon double bonds (n-alkenes, alkenoic acids, mono- and polyunsaturated fatty acid methyl and ethyl esters). Copyright © 2016 Elsevier B.V. All rights reserved.

Highly non-linear solid core photonic crystal fiber with one nano hole

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

Gangwar, Rahul Kumar, E-mail: rahul0889@gmail.com; Bhardwaj, Vanita, E-mail: bhardwajphy12@gmail.com; Singh, Vinod Kumar, E-mail: singh.vk.ap@ismdhanbad.co.in

2015-08-28

The numerical study of newly designed solid core photonic crystal fiber (SCPCF) having three hexagonal air hole rings in cladding region and one small nano hole at the center are presented. By using full vectorial finite element method (FV-FEM), we analyses the optical properties like effective area, nonlinearity and confinement loss of the proposed PCF. Results show that the change in core diameter controls the effective area, nonlinearity and confinement loss. A low effective area (3.34 µm{sup 2}), high nonlinearity (36.34 W{sup −1}km{sup −1}) and low confinement loss (0.00106 dB/km) are achieved at the communication wavelength 1.55 µm for themore » SCPCF having core air hole diameter 0.10 µm, cladding air holes diameter 1.00 µm and pitch 2.50 µm. This type of PCF is very useful in non-linear applications such as supercontinuum generation, four wave mixing, second harmonic generation etc.« less

Solid oxide fuel cell steam reforming power system

DOEpatents

Chick, Lawrence A.; Sprenkle, Vincent L.; Powell, Michael R.; Meinhardt, Kerry D.; Whyatt, Greg A.

2013-03-12

The present invention is a Solid Oxide Fuel Cell Reforming Power System that utilizes adiabatic reforming of reformate within this system. By utilizing adiabatic reforming of reformate within the system the system operates at a significantly higher efficiency than other Solid Oxide Reforming Power Systems that exist in the prior art. This is because energy is not lost while materials are cooled and reheated, instead the device operates at a higher temperature. This allows efficiencies higher than 65%.

Packaging of solid state devices

DOEpatents

Glidden, Steven C.; Sanders, Howard D.

2006-01-03

A package for one or more solid state devices in a single module that allows for operation at high voltage, high current, or both high voltage and high current. Low thermal resistance between the solid state devices and an exterior of the package and matched coefficient of thermal expansion between the solid state devices and the materials used in packaging enables high power operation. The solid state devices are soldered between two layers of ceramic with metal traces that interconnect the devices and external contacts. This approach provides a simple method for assembling and encapsulating high power solid state devices.

In situ formation of a 3D core-shell and triple-conducting oxygen reduction reaction electrode for proton-conducting SOFCs

NASA Astrophysics Data System (ADS)

Zhang, Zhenbao; Wang, Jian; Chen, Yubo; Tan, Shaozao; Shao, Zongping; Chen, Dengjie

2018-05-01

BaZrxCeyY1-x-yO3-δ are recognized proton-conducting electrolyte materials for proton-conducting solid oxide fuel cells (H+-SOFCs) below 650 °C. Here Co cations are incorporated into the BaZr0.4Ce0.4Y0.2O3-δ (BZCY) scaffold to generate a 3D core-shell and triple-conducting (H+/O2-/e-) electrode in situ via infiltrating and reactive sintering. The core is the bulk BZCY scaffold, while the shell is composed of the cubic Ba(Zr0.4Ce0.4Y0.2)1-xCoxO3-δ, cubic spinel Co3O4 and cubic fluorite (Ce, Zr, Y)O2. The obtained electrode exhibits an excellent compatibility with the BZCY electrolyte, and performs well in yielding a low and stable polarization resistance for oxygen reduction reaction for intermediate-temperature H+-SOFCs. In particular, it achieves polarization resistances as low as 0.094 and 0.198 Ω cm2 at 650 and 600 °C in wet air (3% H2O) when the sintering temperature for the electrode is 900 °C. In addition, a symmetrical cell also exhibits operation stability of 70 h at 650 °C. Furthermore, a fuel cell assembled with the 3D core-shell and triple-conducting electrode delivers a peak power density of ∼330 mW cm-2 at 650 °C. The substantially improved electrochemical performance and high stability are ascribed to the unique core-shell structure and the formation of Ba(Zr0.4Ce0.4Y0.2)1-xCoxO3-δ in the shell.

Phytoscreening for chlorinated solvents using rapid in vitro SPME sampling: Application to urban plume in Verl, Germany

USGS Publications Warehouse

Limmer, M.A.; Balouet, J.-C.; Karg, F.; Vroblesky, D.A.; Burken, J.G.

2011-01-01

Rapid detection and delineation of contaminants in urban settings is critically important in protecting human health. Cores from trees growing above a plume of contaminated groundwater in Verl, Germany, were collected in 1 day, with subsequent analysis and plume mapping completed over several days. Solid-phase microextraction (SPME) analysis was applied to detect tetrachloroethene (PCE) and trichloroethene (TCE) to below nanogram/liter levels in the transpiration stream of the trees. The tree core concentrations showed a clear areal correlation to the distribution of PCE and TCE in the groundwater. Concentrations in tree cores were lower than the underlying groundwater, as anticipated; however, the tree core water retained the PCE:TCE signature of the underlying groundwater in the urban, populated area. The PCE:TCE ratio can indicate areas of differing degradation activity. Therefore, the phytoscreening analysis was capable not only of mapping the spatial distribution of groundwater contamination but also of delineating zones of potentially differing contaminant sources and degradation. The simplicity of tree coring and the ability to collect a large number of samples in a day with minimal disruption or property damage in the urban setting demonstrates that phytoscreening can be a powerful tool for gaining reconnaissance-level information on groundwater contaminated by chlorinated solvents. The use of SPME decreases the detection level considerably and increases the sensitivity of phytoscreening as an assessment, monitoring, and phytoforensic tool. With rapid, inexpensive, and noninvasive methods of detecting and delineating contaminants underlying homes, as in this case, human health can be better protected through screening of broader areas and with far faster response times. ?? 2011 American Chemical Society.

Carbon source and energy harvesting optimization in solid anolyte microbial fuel cells

NASA Astrophysics Data System (ADS)

Adekunle, Ademola; Raghavan, Vijaya; Tartakovsky, Boris

2017-07-01

This work investigates the application of a solid anolyte microbial fuel cell (saMFC) as a long-lasting source of electricity for powering electronic devices. Broadly available biodegradable materials such as humus, cattle manure, peat moss, and sawdust are evaluated as solid anolytes. The initial comparison shows significantly higher power production in the saMFC operated using humus as compared to other solid anolytes. At the same time, power production in the humus-based saMFC is found to decline after about 40 days of operation, while the sawdust MFC demonstrates stable performance over the test period. Following this initial comparison, a combined humus - sawdust anolyte is developed to increase saMFC life span. The optimized saMFC demonstrates stable power production for over nine months. Furthermore, power production in the saMFC is maximized by using an intermittent connection to an electrical load (on/off operation) and optimizing the connection/disconnection times. These results demonstrate the feasibility of utilizing solid anolytes for developing inexpensive and long-lasting biobatteries operated on renewable carbon sources.

Solid state RF power: The route to 1W per euro cent

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

Heid, Oliver

2013-04-19

In most particle accelerators RF power is a decisive design constraint due to high costs and relative inflexibility of current electron beam based RF sources, i.e. Klystrons, Magnetrons, Tetrodes etc. At VHF/UHF frequencies the transition to solid state devices promises to fundamentally change the situation. Recent progress brings 1 Watt per Euro cent installed cost within reach. We present a Silicon Carbide semiconductor solution utilising the Solid State Direct Drive technology at unprecedented efficiency, power levels and power densities. The proposed solution allows retrofitting of existing RF accelerators and opens the route to novel particle accelerator concepts.

Neodymium-doped phosphate fiber lasers with an all-solid microstructured inner cladding.

PubMed

Zhang, Guang; Zhou, Qinling; Yu, Chunlei; Hu, Lili; Chen, Danping

2012-06-15

We report on high-power fiber lasers based on index-guiding, all-solid neodymium-doped (Nd-doped) phosphate photonic crystal fiber (PCF) with a hexagonal-shaped inner cladding. The optimum fiber laser with a 36 cm length active fiber, generated up to 7.92 W output power at 1053 nm, which benefited from a high absorption coefficient for pump power due to its noncircular inner cladding. The guiding properties of the all-solid PCF were also investigated. A stable mode with a donut-shaped profile and a power-dependent laser beam quality have been observed experimentally and analyzed.

Parallelizing Compiler Framework and API for Power Reduction and Software Productivity of Real-Time Heterogeneous Multicores

NASA Astrophysics Data System (ADS)

Hayashi, Akihiro; Wada, Yasutaka; Watanabe, Takeshi; Sekiguchi, Takeshi; Mase, Masayoshi; Shirako, Jun; Kimura, Keiji; Kasahara, Hironori

Heterogeneous multicores have been attracting much attention to attain high performance keeping power consumption low in wide spread of areas. However, heterogeneous multicores force programmers very difficult programming. The long application program development period lowers product competitiveness. In order to overcome such a situation, this paper proposes a compilation framework which bridges a gap between programmers and heterogeneous multicores. In particular, this paper describes the compilation framework based on OSCAR compiler. It realizes coarse grain task parallel processing, data transfer using a DMA controller, power reduction control from user programs with DVFS and clock gating on various heterogeneous multicores from different vendors. This paper also evaluates processing performance and the power reduction by the proposed framework on a newly developed 15 core heterogeneous multicore chip named RP-X integrating 8 general purpose processor cores and 3 types of accelerator cores which was developed by Renesas Electronics, Hitachi, Tokyo Institute of Technology and Waseda University. The framework attains speedups up to 32x for an optical flow program with eight general purpose processor cores and four DRP(Dynamically Reconfigurable Processor) accelerator cores against sequential execution by a single processor core and 80% of power reduction for the real-time AAC encoding.

Conceptual Core Analysis of Long Life PWR Utilizing Thorium-Uranium Fuel Cycle

NASA Astrophysics Data System (ADS)

Rouf; Su'ud, Zaki

2016-08-01

Conceptual core analysis of long life PWR utilizing thorium-uranium based fuel has conducted. The purpose of this study is to evaluate neutronic behavior of reactor core using combined thorium and enriched uranium fuel. Based on this fuel composition, reactor core have higher conversion ratio rather than conventional fuel which could give longer operation length. This simulation performed using SRAC Code System based on library SRACLIB-JDL32. The calculation carried out for (Th-U)O2 and (Th-U)C fuel with uranium composition 30 - 40% and gadolinium (Gd2O3) as burnable poison 0,0125%. The fuel composition adjusted to obtain burn up length 10 - 15 years under thermal power 600 - 1000 MWt. The key properties such as uranium enrichment, fuel volume fraction, percentage of uranium are evaluated. Core calculation on this study adopted R-Z geometry divided by 3 region, each region have different uranium enrichment. The result show multiplication factor every burn up step for 15 years operation length, power distribution behavior, power peaking factor, and conversion ratio. The optimum core design achieved when thermal power 600 MWt, percentage of uranium 35%, U-235 enrichment 11 - 13%, with 14 years operation length, axial and radial power peaking factor about 1.5 and 1.2 respectively.

Fission-powered in-core thermoacoustic sensor

DOE PAGES

Garrett, Steven L.; Smith, James A.; Smith, Robert W. M.; ...

2016-04-07

A thermoacoustic engine is operated within the core of a nuclear reactor to acoustically telemeter coolant temperature (frequency-encoded) and reactor power level (amplitude-encoded) outside the reactor, thus providing the values of these important parameters without external electrical power or wiring. We present data from two hydrophones in the coolant (far from the core) and an accelerometer attached to a structure outside the reactor. Furthermore, these signals have been detected even in the presence of substantial background noise generated by the reactor's fluid pumps.

Fission-powered in-core thermoacoustic sensor

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

Garrett, Steven L.; Smith, James A.; Smith, Robert W. M.

2016-04-04

A thermoacoustic engine is operated within the core of a nuclear reactor to acoustically telemeter coolant temperature (frequency-encoded) and reactor power level (amplitude-encoded) outside the reactor, thus providing the values of these important parameters without external electrical power or wiring. We present data from two hydrophones in the coolant (far from the core) and an accelerometer attached to a structure outside the reactor. These signals have been detected even in the presence of substantial background noise generated by the reactor's fluid pumps.

Solar power satellite system definition study, volume 4, phase 2

NASA Technical Reports Server (NTRS)

1979-01-01

Results of an overall evaluation of the solar power satellite concept are reported. Specific topics covered include: solid state sandwich configuration; parametric development of reliability design; power distribution system for solid state solar power satellites; multibeam transmission; GEO base system configuration; suppression of the heavy lift launch vehicle trajectory; conceptual design of an offshore space center facility; solar power satellite development and operations scenario; and microwave power transmission technology, advancement, development, and facility requirements.

A highly efficient and compact long pulse Nd:YAG rod laser with 540 J of pulse energy for welding application.

PubMed

Choubey, Ambar; Vishwakarma, S C; Misra, Pushkar; Jain, R K; Agrawal, D K; Arya, R; Upadhyaya, B N; Oak, S M

2013-07-01

We have developed an efficient and high average power flash lamp pumped long pulse Nd:YAG laser capable of generating 1 kW of average output power with maximum 540 J of single pulse energy and 20 kW of peak power. The laser pulse duration can be varied from 1 to 40 ms and repetition rate from 1 to 100 Hz. A compact and robust laser pump chamber and resonator was designed to achieve this high average and peak power. It was found that this laser system provides highest single pulse energy as compared to other long pulsed Nd:YAG laser systems of similar rating. A slope efficiency of 5.4% has been achieved, which is on higher side for typical lamp pumped solid-state lasers. This system will be highly useful in laser welding of materials such as aluminium and titanium. We have achieved 4 mm deep penetration welding of these metals under optimized conditions of output power, pulse energy, and pulse duration. The laser resonator was optimized to provide stable operation from single shot to 100 Hz of repetition rate. The beam quality factor was measured to be M(2) ~ 91 and pulse-to-pulse stability of ±3% for the multimode operation. The laser beam was efficiently coupled through an optical fiber of 600 μm core diameter and 0.22 numerical aperture with power transmission of 90%.

Phase-stable, multi-µJ femtosecond pulses from a repetition-rate tunable Ti:Sa-oscillator-seeded Yb-fiber amplifier

NASA Astrophysics Data System (ADS)

Saule, T.; Holzberger, S.; De Vries, O.; Plötner, M.; Limpert, J.; Tünnermann, A.; Pupeza, I.

2017-01-01

We present a high-power, MHz-repetition-rate, phase-stable femtosecond laser system based on a phase-stabilized Ti:Sa oscillator and a multi-stage Yb-fiber chirped-pulse power amplifier. A 10-nm band around 1030 nm is split from the 7-fs oscillator output and serves as the seed for subsequent amplification by 54 dB to 80 W of average power. The µJ-level output is spectrally broadened in a solid-core fiber and compressed to 30 fs with chirped mirrors. A pulse picker prior to power amplification allows for decreasing the repetition rate from 74 MHz by a factor of up to 4 without affecting the pulse parameters. To compensate for phase jitter added by the amplifier to the feed-forward phase-stabilized seeding pulses, a self-referencing feed-back loop is implemented at the system output. An integrated out-of-loop phase noise of less than 100 mrad was measured in the band from 0.4 Hz to 400 kHz, which to the best of our knowledge corresponds to the highest phase stability ever demonstrated for high-power, multi-MHz-repetition-rate ultrafast lasers. This system will enable experiments in attosecond physics at unprecedented repetition rates, it offers ideal prerequisites for the generation and field-resolved electro-optical sampling of high-power, broadband infrared pulses, and it is suitable for phase-stable white light generation.

The Liquid Annular Reactor System (LARS) propulsion

NASA Technical Reports Server (NTRS)

Powell, James; Ludewig, Hans; Horn, Frederick; Lenard, Roger

1990-01-01

A concept for very high specific impulse (greater than 2000 seconds) direct nuclear propulsion is described. The concept, termed the liquid annular reactor system (LARS), uses liquid nuclear fuel elements to heat hydrogen propellant to very high temperatures (approximately 6000 K). Operating pressure is moderate (approximately 10 atm), with the result that the outlet hydrogen is virtually 100 percent dissociated to monatomic H. The molten fuel is contained in a solid container of its own material, which is rotated to stabilize the liquid layer by centripetal force. LARS reactor designs are described, together with neutronic and thermal-hydraulic analyses. Power levels are on the order of 200 megawatts. Typically, LARS designs use seven rotating fuel elements, are beryllium moderated, and have critical radii of approximately 100 cm (core L/D approximately equal to 1.5).

High-Efficiency Power Module

NASA Technical Reports Server (NTRS)

Simons, Rainee N (Inventor); Wintucky, Edwin G (Inventor)

2013-01-01

One or more embodiments of the present invention pertain to an all solid-state microwave power module. The module includes a plurality of solid-state amplifiers configured to amplify a signal using a low power stage, a medium power stage, and a high power stage. The module also includes a power conditioner configured to activate a voltage sequencer (e.g., bias controller) when power is received from a power source. The voltage sequencer is configured to sequentially apply voltage to a gate of each amplifier and sequentially apply voltage to a drain of each amplifier.

High-Efficiency Power Module

NASA Technical Reports Server (NTRS)

Simons, Rainee N. (Inventor); Wintucky, Edwin G. (Inventor)

2015-01-01

One or more embodiments of the present invention pertain to an all solid-state microwave power module. The module includes a plurality of solid-state amplifiers configured to amplify a signal using a low power stage, a medium power stage, and a high power stage. The module also includes a power conditioner configured to activate a voltage sequencer (e.g., bias controller) when power is received from a power source. The voltage sequencer is configured to sequentially apply voltage to a gate of each amplifier and sequentially apply voltage to a drain of each amplifier.

Self powered neutron detectors as in-core detectors for Sodium-cooled Fast Reactors

NASA Astrophysics Data System (ADS)

Verma, V.; Barbot, L.; Filliatre, P.; Hellesen, C.; Jammes, C.; Svärd, S. Jacobsson

2017-07-01

Neutron flux monitoring system forms an integral part of the design of a Generation IV sodium cooled fast reactor. Diverse possibilities of detector system installation must be studied for various locations in the reactor vessel in order to detect any perturbations in the core. Results from a previous paper indicated that it is possible to detect changes in neutron source distribution initiated by an inadvertent withdrawal of outer control rod with in-vessel fission chambers located azimuthally around the core. It is, however, not possible to follow inner control rod withdrawal and precisely know the location of the perturbation in the core. Hence the use of complimentary in-core detectors coupled with the peripheral fission chambers is proposed to enable robust core monitoring across the radial direction. In this paper, we assess the feasibility of using self-powered neutron detectors (SPNDs) as in-core detectors in fast reactors for detecting local changes in the power distribution when the reactor is operated at nominal power. We study the neutron and gamma contributions to the total output current of the detector modelled with Platinum as the emitter material. It is shown that this SPND placed in an SFR-like environment would give a sufficiently measurable prompt neutron induced current of the order of 600 nA/m. The corresponding induced current in the connecting cable is two orders of magnitude lower and can be neglected. This means that the SPND can follow in-core power fluctuations. This validates the operability of an SPND in an SFR-like environment.

Solid-phase synthesis of self-assembling multivalent π-conjugated peptides

DOE PAGES

Sanders, Allix M.; Kale, Tejaswini S.; Katz, Howard E.; ...

2017-02-07

Here, we present a completely solid-phase synthetic strategy to create three- and four-fold peptide-appended π-electron molecules, where the multivalent oligopeptide presentation is dictated by the symmetries of reactive handles placed on discotic π-conjugated cores. Carboxylic acid and anhydride groups were viable amidation and imidation partners, respectively, and oligomeric π-electron discotic cores were prepared through Pd-catalyzed cross-couplings. Due to intermolecular hydrogen bonding between the three or four peptide axes, these π-peptide hybrids self-assemble into robust one-dimensional nanostructures with high aspect ratios in aqueous solution. The preparation of these systems via solid-phase methods will be detailed along with their self-assembly properties, asmore » revealed by steady-state spectroscopy and transmission electron microscopy and electrical characterization using field-effect transistor measurements.« less

Uncovering Nature’s 100 TeV Particle Accelerators in the Large-Scale Jets of Quasars

NASA Astrophysics Data System (ADS)

Georganopoulos, Markos; Meyer, Eileen; Sparks, William B.; Perlman, Eric S.; Van Der Marel, Roeland P.; Anderson, Jay; Sohn, S. Tony; Biretta, John A.; Norman, Colin Arthur; Chiaberge, Marco

2016-04-01

Since the first jet X-ray detections sixteen years ago the adopted paradigm for the X-ray emission has been the IC/CMB model that requires highly relativistic (Lorentz factors of 10-20), extremely powerful (sometimes super-Eddington) kpc scale jets. R I will discuss recently obtained strong evidence, from two different avenues, IR to optical polarimetry for PKS 1136-135 and gamma-ray observations for 3C 273 and PKS 0637-752, ruling out the EC/CMB model. Our work constrains the jet Lorentz factors to less than ~few, and leaves as the only reasonable alternative synchrotron emission from ~100 TeV jet electrons, accelerated hundreds of kpc away from the central engine. This refutes over a decade of work on the jet X-ray emission mechanism and overall energetics and, if confirmed in more sources, it will constitute a paradigm shift in our understanding of powerful large scale jets and their role in the universe. Two important findings emerging from our work will also discussed be: (i) the solid angle-integrated luminosity of the large scale jet is comparable to that of the jet core, contrary to the current belief that the core is the dominant jet radiative outlet and (ii) the large scale jets are the main source of TeV photon in the universe, something potentially important, as TeV photons have been suggested to heat up the intergalactic medium and reduce the number of dwarf galaxies formed.

Analysis of Stainless Steel Sandwich Panels with a Metal Foam Care for Lightweight Fan Blade Design

NASA Technical Reports Server (NTRS)

Min, James B.; Ghosn, Louis J.; Lerch, Bradley A.; Raj, Sai V.; Holland, Frederic A., Jr.; Hebsur, Mohan G.

2004-01-01

The quest for cheap, low density and high performance materials in the design of aircraft and rotorcraft engine fan and propeller blades poses immense challenges to the materials and structural design engineers. Traditionally, these components have been fabricated using expensive materials such as light weight titanium alloys, polymeric composite materials and carbon-carbon composites. The present study investigates the use of P sandwich foam fan blade made up of solid face sheets and a metal foam core. The face sheets and the metal foam core material were an aerospace grade precipitation hardened 17-4 PH stainless steel with high strength and high toughness. The stiffness of the sandwich structure is increased by separating the two face sheets by a foam core. The resulting structure possesses a high stiffness while being lighter than a similar solid construction. Since the face sheets carry the applied bending loads, the sandwich architecture is a viable engineering concept. The material properties of 17-4 PH metal foam are reviewed briefly to describe the characteristics of the sandwich structure for a fan blade application. A vibration analysis for natural frequencies and P detailed stress analysis on the 17-4 PH sandwich foam blade design for different combinations of skin thickness and core volume %re presented with a comparison to a solid titanium blade.

An Efficient Analysis Methodology for Fluted-Core Composite Structures

NASA Technical Reports Server (NTRS)

Oremont, Leonard; Schultz, Marc R.

2012-01-01

The primary loading condition in launch-vehicle barrel sections is axial compression, and it is therefore important to understand the compression behavior of any structures, structural concepts, and materials considered in launch-vehicle designs. This understanding will necessarily come from a combination of test and analysis. However, certain potentially beneficial structures and structural concepts do not lend themselves to commonly used simplified analysis methods, and therefore innovative analysis methodologies must be developed if these structures and structural concepts are to be considered. This paper discusses such an analysis technique for the fluted-core sandwich composite structural concept. The presented technique is based on commercially available finite-element codes, and uses shell elements to capture behavior that would normally require solid elements to capture the detailed mechanical response of the structure. The shell thicknesses and offsets using this analysis technique are parameterized, and the parameters are adjusted through a heuristic procedure until this model matches the mechanical behavior of a more detailed shell-and-solid model. Additionally, the detailed shell-and-solid model can be strategically placed in a larger, global shell-only model to capture important local behavior. Comparisons between shell-only models, experiments, and more detailed shell-and-solid models show excellent agreement. The discussed analysis methodology, though only discussed in the context of fluted-core composites, is widely applicable to other concepts.

Models of the earth's core

NASA Technical Reports Server (NTRS)

Stevenson, D. J.

1981-01-01

Combined inferences from seismology, high-pressure experiment and theory, geomagnetism, fluid dynamics, and current views of terrestrial planetary evolution lead to models of the earth's core with five basic properties. These are that core formation was contemporaneous with earth accretion; the core is not in chemical equilibrium with the mantle; the outer core is a fluid iron alloy containing significant quantities of lighter elements and is probably almost adiabatic and compositionally uniform; the more iron-rich inner solid core is a consequence of partial freezing of the outer core, and the energy release from this process sustains the earth's magnetic field; and the thermodynamic properties of the core are well constrained by the application of liquid-state theory to seismic and labroatory data.

A solid-phase glycosyltransferase assay for high-throughput screening in drug discovery research.

PubMed

Donovan, R S; Datti, A; Baek, M G; Wu, Q; Sas, I J; Korczak, B; Berger, E G; Roy, R; Dennis, J W

1999-10-01

Glycosyltransferases mediate changes in glycosylation patterns which, in turn, may affect the function of glycoproteins and/or glycolipids and, further downstream, processes of development, differentiation, transformation and cell-cell recognition. Such enzymes, therefore, represent valid targets for drug discovery. We have developed a solid-phase glycosyltransferase assay for use in a robotic high-throughput format. Carbohydrate acceptors coupled covalently to polyacrylamide are coated onto 96-well plastic plates. The glycosyltransferase reaction is performed with recombinant enzymes and radiolabeled sugar-nucleotide donor at 37 degrees C, followed by washing, addition of scintillation counting fluid, and measurement of radioactivity using a 96-well beta-counter. Glycopolymer construction and coating of the plastic plates, enzyme and substrate concentrations, and linearity with time were optimized using recombinant Core 2 beta1-6-N-acetylglucosaminyltransferase (Core 2 GlcNAc-T). This enzyme catalyzes a rate-limiting reaction for expression of polylactosamine and the selectin ligand sialyl-Lewis(x) in O-glycans. A glycopolymer acceptor for beta1-6-N-acetylglucosaminyltransferase V was also designed and shown to be effective in the solid-phase assay. In a high-throughput screen of a microbial extract library, the coefficient of variance for positive controls was 9.4%, and high concordance for hit validation was observed between the Core 2 GlcNAc-T solid-phase assay and a standard solution-phase assay. The solid-phase assay format, which can be adapted for a variety of glycosyltransferase enzymes, allowed a 5-6 fold increase in throughput compared to the corresponding solution-phase assay.

Advanced Burner Reactor with Breed-and-Burn Thorium Blankets for Improved Economics and Resource Utilization

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

Greenspan, Ehud

2015-11-04

This study assesses the feasibility of designing Seed and Blanket (S&B) Sodium-cooled Fast Reactor (SFR) to generate a significant fraction of the core power from radial thorium fueled blankets that operate on the Breed-and-Burn (B&B) mode without exceeding the radiation damage constraint of presently verified cladding materials. The S&B core is designed to maximize the fraction of neutrons that radially leak from the seed (or “driver”) into the subcritical blanket and reduce neutron loss via axial leakage. The blanket in the S&B core makes beneficial use of the leaking neutrons for improved economics and resource utilization. A specific objective ofmore » this study is to maximize the fraction of core power that can be generated by the blanket without violating the thermal hydraulic and material constraints. Since the blanket fuel requires no reprocessing along with remote fuel fabrication, a larger fraction of power from the blanket will result in a smaller fuel recycling capacity and lower fuel cycle cost per unit of electricity generated. A unique synergism is found between a low conversion ratio (CR) seed and a B&B blanket fueled by thorium. Among several benefits, this synergism enables the very low leakage S&B cores to have small positive coolant voiding reactivity coefficient and large enough negative Doppler coefficient even when using inert matrix fuel for the seed. The benefits of this synergism are maximized when using an annular seed surrounded by an inner and outer thorium blankets. Among the high-performance S&B cores designed to benefit from this unique synergism are: (1) the ultra-long cycle core that features a cycle length of ~7 years; (2) the high-transmutation rate core where the seed fuel features a TRU CR of 0.0. Its TRU transmutation rate is comparable to that of the reference Advanced Burner Reactor (ABR) with CR of 0.5 and the thorium blanket can generate close to 60% of the core power; but requires only one sixth of the reprocessing and fabrication capacity per unit of core power. Nevertheless, these high-performance cores were designed to set upper bounds on the S&B core performance by using larger height and pressure drop than those of typical SFR design. A study was subsequently undertaken to quantify the tradeoff between S&B core design variables and the core performance. This study concludes that a viable S&B core can be designed without significant deviation from SFR core design practices. For example, the S&B core with 120cm active height will be comparable in volume, HM mass and specific power with the S-PRISM core and could fit within the S-PRISM reactor vessel. 43% of this core power will be generated by the once-through thorium blanket; the required capacity for reprocessing and remote fuel fabrication per unit of electricity generated will be approximately one fifth of that for a comparable ABR. The sodium void worth of this 120cm tall S&B core is significantly less positive than that of the reference ABR and the Doppler coefficient is only slightly smaller even though the seed uses a fertile-free fuel. The seed in the high transmutation core requires inert matrix fuel (TRU-40Zr) that has been successfully irradiated by the Fuel Cycle Research & Development program. An additional sensitivity analysis was later conducted to remove the bias introduced by the discrepancy between radiation damage constraints -- 200 DPA applied for S&B cores and fast fluence of 4x1023 n(>0.1MeV)/cm2 applied for ABR core design. Although the performance characteristics of the S&B cores are sensitive to the radiation damage constraint applied, the S&B cores offer very significant performance improvements relative to the conventional ABR core design when using identical constraint.« less

Solid-state power controller

NASA Technical Reports Server (NTRS)

Fox, D. A.; Fullemann, J. S.

1980-01-01

Compact, solid state, electric-power controller switches power on and off at remote load, limits current drawn by load, and shuts off (with 2- to 3- second trip time) in case of short circuit. Lightweight efficient hybrid unit operates at 28 volts dc and at maximum currents of from 3 to 2 amperes.

The curious case of Mercury's internal structure

NASA Astrophysics Data System (ADS)

Hauck, Steven A.; Margot, Jean-Luc; Solomon, Sean C.; Phillips, Roger J.; Johnson, Catherine L.; Lemoine, Frank G.; Mazarico, Erwan; McCoy, Timothy J.; Padovan, Sebastiano; Peale, Stanton J.; Perry, Mark E.; Smith, David E.; Zuber, Maria T.

2013-06-01

The recent determination of the gravity field of Mercury and new Earth-based radar observations of the planet's spin state afford the opportunity to explore Mercury's internal structure. These observations provide estimates of two measures of the radial mass distribution of Mercury: the normalized polar moment of inertia and the fractional polar moment of inertia of the solid portion of the planet overlying the liquid core. Employing Monte Carlo techniques, we calculate several million models of the radial density structure of Mercury consistent with its radius and bulk density and constrained by these moment of inertia parameters. We estimate that the top of the liquid core is at a radius of 2020 ± 30 km, the mean density above this boundary is 3380 ± 200 kg m-3, and the density below the boundary is 6980 ± 280 kg m-3. We find that these internal structure parameters are robust across a broad range of compositional models for the core and planet as a whole. Geochemical observations of Mercury's surface by MESSENGER indicate a chemically reducing environment that would favor the partitioning of silicon or both silicon and sulfur into the metallic core during core-mantle differentiation. For a core composed of Fe-S-Si materials, the thermodynamic properties at elevated pressures and temperatures suggest that an FeS-rich layer could form at the top of the core and that a portion of it may be presently solid.

Age of Jupiter inferred from the distinct genetics and formation times of meteorites

DOE PAGES

Kruijer, Thomas S.; Burkhardt, Christoph; Budde, Gerrit; ...

2017-06-12

The age of Jupiter, the largest planet in our Solar System, is still unknown. Gas-giant planet formation likely involved the growth of large solid cores, followed by the accumulation of gas onto these cores. Thus, the gas-giant cores must have formed before dissipation of the solar nebula, which likely occurred within less than 10 My after Solar System formation. Although such rapid accretion of the gas-giant cores has successfully been modeled, until now it has not been possible to date their formation. Here, using molybdenum and tungsten isotope measurements on iron meteorites, we demonstrate that meteorites derive from two geneticallymore » distinct nebular reservoirs that coexisted and remained spatially separated between ~1 My and ~3–4 My after Solar System formation. The most plausible mechanism for this efficient separation is the formation of Jupiter, opening a gap in the disk and preventing the exchange of material between the two reservoirs. As such, our results indicate that Jupiter’s core grew to ~20 Earth masses within <1 My, followed by a more protracted growth to ~50 Earth masses until at least ~3–4 My after Solar System formation. Furthermore, Jupiter is the oldest planet of the Solar System, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation.« less

Age of Jupiter inferred from the distinct genetics and formation times of meteorites

NASA Astrophysics Data System (ADS)

Kruijer, Thomas S.; Burkhardt, Christoph; Budde, Gerrit; Kleine, Thorsten

2017-06-01

The age of Jupiter, the largest planet in our Solar System, is still unknown. Gas-giant planet formation likely involved the growth of large solid cores, followed by the accumulation of gas onto these cores. Thus, the gas-giant cores must have formed before dissipation of the solar nebula, which likely occurred within less than 10 My after Solar System formation. Although such rapid accretion of the gas-giant cores has successfully been modeled, until now it has not been possible to date their formation. Here, using molybdenum and tungsten isotope measurements on iron meteorites, we demonstrate that meteorites derive from two genetically distinct nebular reservoirs that coexisted and remained spatially separated between ˜1 My and ˜3-4 My after Solar System formation. The most plausible mechanism for this efficient separation is the formation of Jupiter, opening a gap in the disk and preventing the exchange of material between the two reservoirs. As such, our results indicate that Jupiter’s core grew to ˜20 Earth masses within <1 My, followed by a more protracted growth to ˜50 Earth masses until at least ˜3-4 My after Solar System formation. Thus, Jupiter is the oldest planet of the Solar System, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation.

Age of Jupiter inferred from the distinct genetics and formation times of meteorites

PubMed Central

Kruijer, Thomas S.; Burkhardt, Christoph; Kleine, Thorsten

2017-01-01

The age of Jupiter, the largest planet in our Solar System, is still unknown. Gas-giant planet formation likely involved the growth of large solid cores, followed by the accumulation of gas onto these cores. Thus, the gas-giant cores must have formed before dissipation of the solar nebula, which likely occurred within less than 10 My after Solar System formation. Although such rapid accretion of the gas-giant cores has successfully been modeled, until now it has not been possible to date their formation. Here, using molybdenum and tungsten isotope measurements on iron meteorites, we demonstrate that meteorites derive from two genetically distinct nebular reservoirs that coexisted and remained spatially separated between ∼1 My and ∼3–4 My after Solar System formation. The most plausible mechanism for this efficient separation is the formation of Jupiter, opening a gap in the disk and preventing the exchange of material between the two reservoirs. As such, our results indicate that Jupiter’s core grew to ∼20 Earth masses within <1 My, followed by a more protracted growth to ∼50 Earth masses until at least ∼3–4 My after Solar System formation. Thus, Jupiter is the oldest planet of the Solar System, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation. PMID:28607079

Age of Jupiter inferred from the distinct genetics and formation times of meteorites

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

Kruijer, Thomas S.; Burkhardt, Christoph; Budde, Gerrit

The age of Jupiter, the largest planet in our Solar System, is still unknown. Gas-giant planet formation likely involved the growth of large solid cores, followed by the accumulation of gas onto these cores. Thus, the gas-giant cores must have formed before dissipation of the solar nebula, which likely occurred within less than 10 My after Solar System formation. Although such rapid accretion of the gas-giant cores has successfully been modeled, until now it has not been possible to date their formation. Here, using molybdenum and tungsten isotope measurements on iron meteorites, we demonstrate that meteorites derive from two geneticallymore » distinct nebular reservoirs that coexisted and remained spatially separated between ~1 My and ~3–4 My after Solar System formation. The most plausible mechanism for this efficient separation is the formation of Jupiter, opening a gap in the disk and preventing the exchange of material between the two reservoirs. As such, our results indicate that Jupiter’s core grew to ~20 Earth masses within <1 My, followed by a more protracted growth to ~50 Earth masses until at least ~3–4 My after Solar System formation. Furthermore, Jupiter is the oldest planet of the Solar System, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation.« less

Age of Jupiter inferred from the distinct genetics and formation times of meteorites.

PubMed

Kruijer, Thomas S; Burkhardt, Christoph; Budde, Gerrit; Kleine, Thorsten

2017-06-27

The age of Jupiter, the largest planet in our Solar System, is still unknown. Gas-giant planet formation likely involved the growth of large solid cores, followed by the accumulation of gas onto these cores. Thus, the gas-giant cores must have formed before dissipation of the solar nebula, which likely occurred within less than 10 My after Solar System formation. Although such rapid accretion of the gas-giant cores has successfully been modeled, until now it has not been possible to date their formation. Here, using molybdenum and tungsten isotope measurements on iron meteorites, we demonstrate that meteorites derive from two genetically distinct nebular reservoirs that coexisted and remained spatially separated between ∼1 My and ∼3-4 My after Solar System formation. The most plausible mechanism for this efficient separation is the formation of Jupiter, opening a gap in the disk and preventing the exchange of material between the two reservoirs. As such, our results indicate that Jupiter's core grew to ∼20 Earth masses within <1 My, followed by a more protracted growth to ∼50 Earth masses until at least ∼3-4 My after Solar System formation. Thus, Jupiter is the oldest planet of the Solar System, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation.

Method of fabricating a monolithic core for a solid oxide fuela cell

DOEpatents

Zwick, S.A.; Ackerman, J.P.

1983-10-12

A method is disclosed for forming a core for use in a solid oxide fuel cell that electrochemically combines fuel and oxidant for generating galvanic output. The core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support consisting instead only of the active anode, cathode, electrolyte and interconnect materials. Each electrolyte wall consists of cathode and anode materials sandwiching electrolyte material therebetween, and each interconnect wall consists of the cathode and anode materials sandwiching interconnect material therebetween. The electrolyte and interconnect walls define a plurality of substantially parallel core passageways alternately having respectively the inside faces thereof with only the anode material or with only the cathode material exposed. In the wall structure, the electrolyte and interconnect materials are only 0.002 to 0.01 cm thick; and the cathode and anode materials are only 0.002 to 0.05 cm thick. The method consists of building up the electrolyte and interconnect walls by depositing each material on individually and endwise of the wall itself, where each material deposit is sequentially applied for one cycle; and where the depositing cycle is repeated many times until the material buildup is sufficient to formulate the core. The core is heat cured to become dimensionally and structurally stable.

Method of fabricating a monolithic core for a solid oxide fuel cell

DOEpatents

Zwick, Stanley A.; Ackerman, John P.

1985-01-01

A method is disclosed for forming a core for use in a solid oxide fuel cell that electrochemically combines fuel and oxidant for generating galvanic output. The core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support consisting instead only of the active anode, cathode, electrolyte and interconnect materials. Each electrolyte wall consists of cathode and anode materials sandwiching electrolyte material therebetween, and each interconnect wall consists of the cathode and anode materials sandwiching interconnect material therebetween. The electrolyte and interconnect walls define a plurality of substantially parallel core passageways alternately having respectively the inside faces thereof with only the anode material or with only the cathode material exposed. In the wall structure, the electrolyte and interconnect materials are only 0.002-0.01 cm thick; and the cathode and anode materials are only 0.002-0.05 cm thick. The method consists of building up the electrolyte and interconnect walls by depositing each material on individually and endwise of the wall itself, where each material deposit is sequentially applied for one cycle; and where the depositing cycle is repeated many times until the material buildup is sufficient to formulate the core. The core is heat cured to become dimensionally and structurally stable.

Principles of scientific research team formation and evolution.

PubMed

Milojević, Staša

2014-03-18

Research teams are the fundamental social unit of science, and yet there is currently no model that describes their basic property: size. In most fields, teams have grown significantly in recent decades. We show that this is partly due to the change in the character of team size distribution. We explain these changes with a comprehensive yet straightforward model of how teams of different sizes emerge and grow. This model accurately reproduces the evolution of empirical team size distribution over the period of 50 y. The modeling reveals that there are two modes of knowledge production. The first and more fundamental mode employs relatively small, "core" teams. Core teams form by a Poisson process and produce a Poisson distribution of team sizes in which larger teams are exceedingly rare. The second mode employs "extended" teams, which started as core teams, but subsequently accumulated new members proportional to the past productivity of their members. Given time, this mode gives rise to a power-law tail of large teams (10-1,000 members), which features in many fields today. Based on this model, we construct an analytical functional form that allows the contribution of different modes of authorship to be determined directly from the data and is applicable to any field. The model also offers a solid foundation for studying other social aspects of science, such as productivity and collaboration.

Design of a Resistively Heated Thermal Hydraulic Simulator for Nuclear Rocket Reactor Cores

NASA Technical Reports Server (NTRS)

Litchford, Ron J.; Foote, John P.; Ramachandran, Narayanan; Wang, Ten-See; Anghaie, Samim

2007-01-01

A preliminary design study is presented for a non-nuclear test facility which uses ohmic heating to replicate the thermal hydraulic characteristics of solid core nuclear reactor fuel element passages. The basis for this testing capability is a recently commissioned nuclear thermal rocket environments simulator, which uses a high-power, multi-gas, wall-stabilized constricted arc-heater to produce high-temperature pressurized hydrogen flows representative of reactor core environments, excepting radiation effects. Initially, the baseline test fixture for this non-nuclear environments simulator was configured for long duration hot hydrogen exposure of small cylindrical material specimens as a low cost means of evaluating material compatibility. It became evident, however, that additional functionality enhancements were needed to permit a critical examination of thermal hydraulic effects in fuel element passages. Thus, a design configuration was conceived whereby a short tubular material specimen, representing a fuel element passage segment, is surrounded by a backside resistive tungsten heater element and mounted within a self-contained module that inserts directly into the baseline test fixture assembly. With this configuration, it becomes possible to create an inward directed radial thermal gradient within the tubular material specimen such that the wall-to-gas heat flux characteristics of a typical fuel element passage are effectively simulated. The results of a preliminary engineering study for this innovative concept are fully summarized, including high-fidelity multi-physics thermal hydraulic simulations and detailed design features.

Insulation Requirements of High-Voltage Power Systems in Future Spacecraft

NASA Technical Reports Server (NTRS)

Qureshi, A. Haq; Dayton, James A., Jr.

1995-01-01

The scope, size, and capability of the nation's space-based activities are limited by the level of electrical power available. Long-term projections show that there will be an increasing demand for electrical power in future spacecraft programs. The level of power that can be generated, conditioned, transmitted, and used will have to be considerably increased to satisfy these needs, and increased power levels will require that transmission voltages also be increased to minimize weight and resistive losses. At these projected voltages, power systems will not operate satisfactorily without the proper electrical insulation. Open or encapsulated power supplies are currently used to keep the volume and weight of space power systems low and to protect them from natural and induced environmental hazards. Circuits with open packaging are free to attain the pressure of the outer environment, whereas encapsulated circuits are imbedded in insulating materials, which are usually solids, but could be liquids or gases. Up to now, solid insulation has usually been chosen for space power systems. If the use of solid insulation is continued, when voltages increase, the amount of insulation for encapsulation also will have to increase. This increased insulation will increase weight and reduce system reliability. Therefore, non-solid insulation media must be examined to satisfy future spacecraft power and voltage demands. In this report, we assess the suitability of liquid, space vacuum, and gas insulation for space power systems.

Understanding the haling power depletion (HPD) method

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

Levine, S.; Blyth, T.; Ivanov, K.

2012-07-01

The Pennsylvania State Univ. (PSU) is using the university version of the Studsvik Scandpower Code System (CMS) for research and education purposes. Preparations have been made to incorporate the CMS into the PSU Nuclear Engineering graduate class 'Nuclear Fuel Management' course. The information presented in this paper was developed during the preparation of the material for the course. The Haling Power Depletion (HPD) was presented in the course for the first time. The HPD method has been criticized as not valid by many in the field even though it has been successfully applied at PSU for the past 20 years.more » It was noticed that the radial power distribution (RPD) for low leakage cores during depletion remained similar to that of the HPD during most of the cycle. Thus, the Haling Power Depletion (HPD) may be used conveniently mainly for low leakage cores. Studies were then made to better understand the HPD and the results are presented in this paper. Many different core configurations can be computed quickly with the HPD without using Burnable Poisons (BP) to produce several excellent low leakage core configurations that are viable for power production. Once the HPD core configuration is chosen for further analysis, techniques are available for establishing the BP design to prevent violating any of the safety constraints in such HPD calculated cores. In summary, in this paper it has been shown that the HPD method can be used for guiding the design for the low leakage core. (authors)« less

Kilovolt dc solid state remote power controller development

NASA Technical Reports Server (NTRS)

Mitchell, J. T.

1982-01-01

The experience gained in developing and applying solid state power controller (SSPC) technology at high voltage dc (HVDC) potentials and power levels of up to 25 kilowatts is summarized. The HVDC switching devices, power switching concepts, drive circuits, and very fast acting overcurrent protection circuits were analyzed. A 25A bipolar breadboard with Darlington connected switching transistor was built. Fault testing at 900 volts was included. A bipolar transistor packaged breadboard design was developed. Power MOSFET remote power controller (RPC) was designed.

High power multiple wavelength diode laser stack for DPSSL application without temperature control

NASA Astrophysics Data System (ADS)

Hou, Dong; Yin, Xia; Wang, Jingwei; Chen, Shi; Zhan, Yun; Li, Xiaoning; Fan, Yingmin; Liu, Xingsheng

2018-02-01

High power diode laser stack is widely used in pumping solid-state laser for years. Normally an integrated temperature control module is required for stabilizing the output power of solid-state laser, as the output power of the solid-state laser highly depends on the emission wavelength and the wavelength shift of diode lasers according to the temperature changes. However the temperature control module is inconvenient for this application, due to its large dimension, high electric power consumption and extra adding a complicated controlling system. Furthermore, it takes dozens of seconds to stabilize the output power when the laser system is turned on. In this work, a compact hard soldered high power conduction cooled diode laser stack with multiple wavelengths is developed for stabilizing the output power of solid-state laser in a certain temperature range. The stack consists of 5 laser bars with the pitch of 0.43mm. The peak output power of each bar in the diode laser stack reaches as much as 557W and the combined lasing wavelength spectrum profile spans 15nm. The solidstate laser, structured with multiple wavelength diode laser stacks, allows the ambient temperature change of 65°C without suddenly degrading the optical performance.

The Hollow Core: Failure of the General Education Curriculum. A Fifty College Study

ERIC Educational Resources Information Center

Latzer, Barry

2004-01-01

This report provides empirical proof of a disturbing trend in higher education. Over the last several decades colleges and universities have substituted so-called "distribution requirements" for a solid core curriculum. Distribution requirements enable students freely to choose their general education courses, the courses outside their…

Development of lunar drill to take core samples to 100-foot depths

NASA Technical Reports Server (NTRS)

1967-01-01

Lunar drill takes lunar surface cores to depths of 100 feet and is being developed to the samples at greater depths. The wireline drill system has been adapted to operate in the lunar environment by providing a sealed dc motor and solid metallic base lubricants.

Comparative assessment of out-of-core nuclear thermionic power systems

NASA Technical Reports Server (NTRS)

Estabrook, W. C.; Koenig, D. R.; Prickett, W. Z.

1975-01-01

The hardware selections available for fabrication of a nuclear electric propulsion stage for planetary exploration were explored. The investigation was centered around a heat-pipe-cooled, fast-spectrum nuclear reactor for an out-of-core power conversion system with sufficient detail for comparison with the in-core system studies completed previously. A survey of competing power conversion systems still indicated that the modular reliability of thermionic converters makes them the desirable choice to provide the 240-kWe end-of-life power for at least 20,000 full power hours. The electrical energy will be used to operate a number of mercury ion bombardment thrusters with a specific impulse in the range of about 4,000-5,000 seconds.

Thermal Evolution and Crystallisation Regimes of the Martian Core

NASA Astrophysics Data System (ADS)

Davies, C. J.; Pommier, A.

2015-12-01

Though it is accepted that Mars has a sulfur-rich metallic core, its chemical and physical state as well as its time-evolution are still unconstrained and debated. Several lines of evidence indicate that an internal magnetic field was once generated on Mars and that this field decayed around 3.7-4.0 Gyrs ago. The standard model assumes that this field was produced by a thermal (and perhaps chemical) dynamo operating in the Martian core. We use this information to construct parameterized models of the Martian dynamo in order to place constraints on the thermochemical evolution of the Martian core, with particular focus on its crystallization regime. Considered compositions are in the FeS system, with S content ranging from ~10 and 16 wt%. Core radius, density and CMB pressure are varied within the errors provided by recent internal structure models that satisfy the available geodetic constraints (planetary mass, moment of inertia and tidal Love number). We also vary the melting curve and adiabat, CMB heat flow and thermal conductivity. Successful models are those that match the dynamo cessation time and fall within the bounds on present-day CMB temperature. The resulting suite of over 500 models suggest three possible crystallization regimes: growth of a solid inner core starting at the center of the planet; freezing and precipitation of solid iron (Fe- snow) from the core-mantle boundary (CMB); and freezing that begins midway through the core. Our analysis focuses on the effects of core properties that are expected to be constrained during the forthcoming Insight mission.

Optimization design of toroidal core for magnetic energy harvesting near power line by considering saturation effect

NASA Astrophysics Data System (ADS)

Park, Bumjin; Kim, Dongwook; Park, Jaehyoung; Kim, Kibeom; Koo, Jay; Park, HyunHo; Ahn, Seungyoung

2018-05-01

Recently, magnetic energy harvesting technologies have been studied actively for self-sustainable operation of applications around power line. However, magnetic energy harvesting around power lines has the problem of magnetic saturation, which can cause power performance degradation of the harvester. In this paper, optimal design of a toroidal core for magnetic energy harvesters has been proposed with consideration of magnetic saturation near power lines. Using Permeability-H curve and Ampere's circuital law, the optimum dimensional parameters needed to generate induced voltage were analyzed via calculation and simulation. To reflect a real environment, we consider the nonlinear characteristic of the magnetic core material and supply current through a 3-phase distribution panel used in the industry. The effectiveness of the proposed design methodology is verified by experiments in a power distribution panel and takes 60.9 V from power line current of 60 A at 60 Hz.

The structure of melting mushy zones, with implications for Earth's inner core (Invited)

NASA Astrophysics Data System (ADS)

Bergman, M. I.; Huguet, L.; Alboussiere, T.

2013-12-01

Seismologists have inferred hemispherical differences in the isotropic wavespeed, the elastic anisotropy, the attenuation, and the attenuation anisotropy of Earth's inner core. One hypothesis for these hemispherical differences involves an east-west translation of the inner core, with enhanced solidification on one side and melting on the other. Another hypothesis is that long term mantle control over outer core convection can lead to hemispherical variations in solidification that could even result in melting in some regions of the inner core boundary. It has also been hypothesized that the inner core is growing dendritically, resulting in an inner core that has the structure of a mushy zone (albeit one with a high solid fraction). It would therefore be helpful to understand how the structure of a melting mushy zone might look in comparison with one that is solidifying, in an effort to help interpret the seismic inferences. We have carried out experiments on the solidification of ammonium chloride from an aqueous solution, yielding a mushy zone. The experiments run in a centrifuge, in order to reach a more realistic ratio of convective velocity to phase change rate, expected to be very large at the boundary of the inner core. Hypergravity thus increases the experimental solid fraction of the mush. So far the maximum gravity we have achieved is 200 g. A Peltier cell provides cooling at one end of the cell, and after the mushy zone has grown we turn on a heater at the other end. Probes monitor the temperature along the height of the cell. As ammonium chloride in the mushy zone melts it produces more dense fluid, which results in convection in the mushy zone, a greater ammonium chloride concentration deeper in the mushy zone, and hence enhanced solidification there. This thus changes the solid fraction profile from that during solidification, which may be observable in the lab experiments using ultrasonic transducers and post-mortem under a microscope. The melting may also change the propagation of chimney convection. It remains unclear whether these changes will be observable seismically.

Solid State Digital Propulsion "Cluster Thrusters" For Small Satellites Using High Performance Electrically Controlled Extinguishable Solid Propellants (ECESP)

NASA Technical Reports Server (NTRS)

Sawka, Wayne N.; Katzakian, Arthur; Grix, Charles

2005-01-01

Electrically controlled extinguishable solid propellants (ESCSP) are capable of multiple ignitions, extinguishments and throttle control by the application of electrical power. Both core and end burning no moving parts ECESP grains/motors to three inches in diameter have now been tested. Ongoing research has led to a newer family of even higher performance ECESP providing up to 10% higher performance, manufacturing ease, and significantly higher electrical conduction. The high conductivity was not found to be desirable for larger motors; however it is ideal for downward scaling to micro and pico- propulsion applications with a web thickness of less than 0.125 inch/ diameter. As a solid solution propellant, this ECESP is molecularly uniform, having no granular structure. Because of this homogeneity and workable viscosity it can be directly cast into thin layers or vacuum cast into complex geometries. Both coaxial and grain stacks have been demonstrated. Combining individual propellant coaxial grains and/or grain stacks together form three-dimensional arrays yield modular cluster thrusters. Adoption of fabless manufacturing methods and standards from the electronics industry will provide custom, highly reproducible micro-propulsion arrays and clusters at low costs. These stack and cluster thruster designs provide a small footprint saving spacecraft surface area for solar panels and/or experiments. The simplicity of these thrusters will enable their broad use on micro-pico satellites for primary propulsion, ACS and formation flying applications. Larger spacecraft may find uses for ECESP thrusters on extended booms, on-orbit refueling, pneumatic actuators, and gas generators.

Satellite Power Systems (SPS) Concept Definition Study (Exhibit D). Solid-State Amplifier Investigation

NASA Technical Reports Server (NTRS)

Hanley, G. M.

1981-01-01

Data resulting from a continuing effort to provide system/subsystem definition data to aid in the evaluation of the SPS program concept is presented. The specific data described relate to the proposed use of solid state devices as microwave power amplifiers in the satellite microwave power transmission subsystem.

Ultrahigh temperature vapor core reactor-MHD system for space nuclear electric power

NASA Technical Reports Server (NTRS)

Maya, Isaac; Anghaie, Samim; Diaz, Nils J.; Dugan, Edward T.

1991-01-01

The conceptual design of a nuclear space power system based on the ultrahigh temperature vapor core reactor with MHD energy conversion is presented. This UF4 fueled gas core cavity reactor operates at 4000 K maximum core temperature and 40 atm. Materials experiments, conducted with UF4 up to 2200 K, demonstrate acceptable compatibility with tungsten-molybdenum-, and carbon-based materials. The supporting nuclear, heat transfer, fluid flow and MHD analysis, and fissioning plasma physics experiments are also discussed.

A comparison of mechanical properties of some foams and honeycombs

NASA Technical Reports Server (NTRS)

Bhat, Balakrishna T.; Wang, T. G.

1990-01-01

A comparative study is conducted of the mechanical properties of foam-core and honeycomb-core sandwich panels, using a normalizing procedure based on common properties of cellular solids and related properties of dense solids. Seven different honeycombs and closed-foam cells are discussed; of these, three are commercial Al alloy honeycombs, one is an Al-alloy foam, and two are polymeric foams. It is concluded that ideal, closed-cell foams may furnish compressive strengths which while isotropic can be fully comparable to the compressive strengths of honeycombs in the thickness direction. The shear strength of ideal closed-cell foams may be superior to the shear strength of honeycombs.

Effect of Ni on Fe FeS phase relations at high pressure and high temperature

NASA Astrophysics Data System (ADS)

Zhang, Li; Fei, Yingwei

2008-04-01

A series of melting experiments in the Fe-rich portion of the Fe-Ni-S system have been conducted at 19-23 GPa and 800-1100 °C. The solubility of S in the Fe-Ni solid alloy and the eutectic melting in the Fe-Ni-S system were determined as a function of Ni content. The maximum S solubility in the Fe-Ni alloy is 2.7 wt.% at 20 GPa and the eutectic temperature. The eutectic melting temperature in the Fe-Ni(5wt.%)-S system is ~ 1000 °C lower than the melting point of pure Fe at 20 GPa. We also found that Ni can substitute Fe in the Fe 3S structure to form (Fe,Ni) 3S solid solutions up to at least a Fe/Ni atomic ratio of 0.5. Similar to melting behavior in the Fe-FeS system, the eutectic melting relations in the Fe-Ni-S system could produce inner and outer cores with the right light element balance to account for the density difference between the solid inner core and the liquid outer core.

Nanofinishing of BK7 glass using a magnetorheological solid rotating core tool.

PubMed

Kumar, Sumit; Singh, Anant Kumar

2018-02-01

Surface finishing is a promising method to improve the optical characteristics of crown glass. BK7 finds its applications in transmissive optics, i.e., lenses of binoculars, lenses of microscopes, lenses of telescopes, and light-emitting diodes. The magnetorheological (MR) nanofinishing of optical glasses using a solid rotating core tool is found more advantageous than the other advanced finishing processes in aspects such as precision and accuracy. In the present research, the MR nanofinishing with a solid rotating core tool is carried out on the BK7 glass of size 10×10×3  mm. Response surface methodology is conducted in order to find the optimum process parameters. The effects of process parameters on the percentage change in surface roughness are analyzed. The best surface roughness R a and R q values are achieved at 22 nm and 32 nm from the initial of 41 nm and 57 nm in 30 min of the finishing time cycle. To study the surface morphology of nanofinished BK7 glass, scanning electron microscopy is performed with sputter coating of gold on a glass specimen.

Insights into Mercury's interior structure from geodesy measurements and global contraction

NASA Astrophysics Data System (ADS)

Rivoldini, A.; Van Hoolst, T.

2014-04-01

The measurements of the gravitational field of Mercury by MESSENGER [6] and improved measurements of the spin state of Mercury [3] provide important insights on its interior structure. In particular, these data give strong constraints on the radius and density of Mercury's core [5, 2]. However, present geodesy data do not provide strong constraints on the radius of the inner core. The data allow for models with a fully molten liquid core to models which have an inner core radius that is smaller than about 1760km [5], if it is assumed that sulfur is the only light element in the core. Models without an inner core are, however, at odds with the observed internally generated magnetic field of Mercury since Mercury's dynamo cannot operate by secular cooling alone at present. The present radius of the inner core depends mainly on Mercury's thermal state and light elements inside the core. Because of the secular cooling of the planet,the temperature inside the core drops below the liquidus temperature of the core material somewhere in the core and leads to the formation of an inner core and to the global contraction of the planet. The amount of contraction depends on the temperature decrease, on the thermal expansion of the materials inside the planet, and on the volume of crystallized liquid core alloy. In this study we use geodesy data, the recent estimate about the radial contraction of Mercury [1], and thermo-chemical evolution calculations in order to improve our knowledge about Mercury's inner core radius and thermal state. Since data from remote sensing of Mercury's surface [4] indicate that Mercury formed under reducing conditions we consider models that have sulfur and silicon as light elements inside their core. Unlike sulfur, which does almost not partition into solid iron under Mercury's core pressure and temperature conditions, silicon partitions virtually equally between solid and liquid iron. As a consequence, the density difference between the liquid and the crystallized material is smaller than for sulfur as only light element inside the core and therefore, for a given inner core radius the contraction of the planet is likely smaller.

Enzyme immobilization in novel alginate-chitosan core-shell microcapsules.

PubMed

Taqieddin, Ehab; Amiji, Mansoor

2004-05-01

Alginate-chitosan core-shell microcapsules were prepared in order to develop a biocompatible matrix for enzyme immobilization, where the protein is retained either in a liquid or solid core and the shell allows permeability control over substrates and products. The permeability coefficients of different molecular weight compounds (vitamin B2, vitamin B12, and myoglobin) were determined through sodium tripolyphosphate (Na-TPP)-crosslinked chitosan membrane. The microcapsule core was formed by crosslinking sodium alginate with either calcium or barium ions. The crosslinked alginate core was uniformly coated with a chitosan layer and crosslinked with Na-TPP. In the case of calcium alginate, the phosphate ions of Na-TPP were able to extract the calcium ions from alginate and liquefy the core. A model enzyme, beta-galactosidase, was immobilized in the alginate core and the catalytic activity was measured with o-nitrophenyl-beta-D-galactopyranoside (ONPG). Change in the activity of free and immobilized enzyme was determined at three different temperatures. Na-TPP crosslinked chitosan membranes were found to be permeable to solutes of up to 17,000Da molecular weight. The enzyme loading efficiency was higher in the barium alginate core (100%) as compared to the calcium alginate core (60%). The rate of ONPG conversion to o-nitrophenol was faster in the case of calcium alginate-chitosan microcapsules as compared to barium alginate-chitosan microcapsules. Barium alginate-chitosan microcapsules, however, did improve the stability of the enzyme at 37 degrees C relative to calcium alginate-chitosan microcapsules or free enzyme. This study illustrates a new method of enzyme immobilization for biotechnology applications using liquid or solid core and shell microcapsule technology.

Achieving High-Energy-High-Power Density in a Flexible Quasi-Solid-State Sodium Ion Capacitor.

PubMed

Li, Hongsen; Peng, Lele; Zhu, Yue; Zhang, Xiaogang; Yu, Guihua

2016-09-14

Simultaneous integration of high-energy output with high-power delivery is a major challenge for electrochemical energy storage systems, limiting dual fine attributes on a device. We introduce a quasi-solid-state sodium ion capacitor (NIC) based on a battery type urchin-like Na2Ti3O7 anode and a capacitor type peanut shell derived carbon cathode, using a sodium ion conducting gel polymer as electrolyte, achieving high-energy-high-power characteristics in solid state. Energy densities can reach 111.2 Wh kg(-1) at power density of 800 W kg(-1), and 33.2 Wh kg(-1) at power density of 11200 W kg(-1), which are among the best reported state-of-the-art NICs. The designed device also exhibits long-term cycling stability over 3000 cycles with capacity retention ∼86%. Furthermore, we demonstrate the assembly of a highly flexible quasi-solid-state NIC and it shows no obvious capacity loss under different bending conditions.

Seismic Structure in the Vicinity of the Inner Core Boundary beneath northeastern Asia

NASA Astrophysics Data System (ADS)

Ibourichene, A. S.; Romanowicz, B. A.

2016-12-01

The inner core boundary (ICB) separates the solid inner core from the liquid outer core. The crystallization of iron occurring at this limit induces the expulsion of lighter elements such as H, O, S, Si into the outer core, generating chemically-driven convection, which provides power for the geodynamo. Both the F layer, right above the ICB, and the uppermost inner core, are affected by this process so that their properties provide important constraints for a better understanding of core dynamics and, ultimately, the generation and sustained character of the earth's magnetic field. In this study, we investigate the evolution of model parameters (P-velocity, density and quality factor) with depth in the vicinity of the ICB. For this purpose, we combine observations of two body wave phases sensitive to this region: the PKP(DF) phase refracted in the inner core and the PKiKP reflected on the ICB. Variations in the PKP(DF)/PKiKP amplitude ratio and PKP(DF)-PKiKP differential travel times can be related to structure around the ICB. We use waveform data from earthquakes located in Sumatra and recorded by the dense USArray seismic network, which allows us to sample ICB structure beneath northeastern Asia. Observed waveforms are compared to synthetics computed using the DSM method (e.g., Geller et Takeuchi, 1995) in model AK135 (e.g., Montagner & Kennett, 1996) in order to measure amplitude and travel time anomalies. Previous studies (e.g., Tanaka, 1997 ; Cao and Romanowicz, 2004, Yu and Wen, 2006; Waszek and Deuss, 2011) have observed an hemispherical pattern in the vicinity of the ICB exhibiting a faster and more attenuated eastern hemisphere compared to the western hemisphere. The region studied is located in the eastern hemisphere. We find that, on average, travel time anomalies are consistent with previous studies of the eastern hemisphere, however, amplitude ratios are not. We conduct a parameter search for the 1D model that best fits our data. We also consider fluctuations around this best fitting average model and quantify the statistical properties of the short wavelength fluctuations.

Soft switching circuit to improve efficiency of all solid-state Marx modulator for DBDs

NASA Astrophysics Data System (ADS)

Liqing, TONG; Kefu, LIU; Yonggang, WANG

2018-02-01

For an all solid-state Marx modulator applied in dielectric barrier discharges (DBDs), hard switching results in a very low efficiency. In this paper, a series resonant soft switching circuit, which series an inductance with DBD capacitor, is proposed to reduce the power loss. The power loss of the all circuit status with hard switching was analyzed, and the maximum power loss occurred during discharging at the rising and falling edges. The power loss of the series resonant soft switching circuit was also presented. A comparative analysis of the two circuits determined that the soft switching circuit greatly reduced power loss. The experimental results also demonstrated that the soft switching circuit improved the power transmission efficiency of an all solid-state Marx modulator for DBDs by up to 3 times.

500-Watt Solid-State RF Power Amplifier AM-7209( )/VRC.

DTIC Science & Technology

1983-03-18

AD-A127 462 580-WRATT SOLID-STATE RF POWER AMPLIFIER AM-7289( )/VRC 1/2 (U) E- SYSTEMS INC ST PETERSBURG FL ECI DIV N HARRIS 18 MAR 83 60-6±289 CECOM...AND DEVELOPMENT TECHNICAL REPORT CECOM-82-C-J23 1 500-WATT SOLID-STATE RF POWER AMPLIFIER AM-7209( )/VRC M. Harris E- SYSTEMS , INC., ECI DIVISION 1502...CONTRACT OR GRANT NUMSER(t) M. Harris DAABO7-82-C-J231 9m PERFORMING ORGANIZATION NAME AND ADDRESS II. PROGRAM ELEMENT. PROJECT TASK E- SYSTEMS , INC

NASA's Space Launch System: Progress Report

NASA Technical Reports Server (NTRS)

Cook, Jerry; Lyles, Garry

2017-01-01

NASA and its commercial industry team achieved significant progress in 2016 in manufacturing and testing of the Block 1 vehicle for the first launch of the Space Launch System (SLS). Test and flight article hardware for the liquid hydrogen fuel tank as well as the engine section for the core stage were completed at Michoud Assembly Facility (MAF) in New Orleans. Test stands neared completion at Marshall Space Flight Center for the propellant tanks, engine section, intertank and payload section. Stennis Space Center completed major structural renovations on the B2 test stand, where the core stage "green run" test program will be conducted. The SLS team completed a hotfire test series at Stennis to successfully demonstrate the ability of the RS-25 engine to operate under SLS environments and performance conditions. The team also test fired the second qualification five-segment solid rocket motor and cast the first six motor segments for the first SLS mission. The Interim Cryogenic Propulsion Stage (ICPS) test article was delivered to Marshall for structural tests, and work is nearly finished on the flight stage. Flight software testing completed at Marshall included power quality and command and data handling. In 2017, that work continues. SLS completed Preliminary Design Review (PDR) on the Exploration Upper Stage (EUS), a powerful, human-rated spacecraft that will propel explorers to cis-lunar space. In 2017, hardware will continue to be integrated at MAF for core stage structural test articles and the first two operational flights. RS-25 hotfire testing will continue to explore engine performance, as well as test flight-like software and four new Engine Controller Units (ECUs) for the first mission. Production of development components for a more affordable RS-25 design is underway. Core stage structural test articles have begun arriving at Marshall. While engineering challenges typical of a new development are possible, SLS is working toward launch readiness in late 2018. This paper will discuss these and other technical and programmatic successes and challenges over the past year and provide a preview of work ahead before first flight

Lunar Rotation, Orientation and Science

NASA Astrophysics Data System (ADS)

Williams, J. G.; Ratcliff, J. T.; Boggs, D. H.

2004-12-01

The Moon is the most familiar example of the many satellites that exhibit synchronous rotation. For the Moon there is Lunar Laser Ranging measurements of tides and three-dimensional rotation variations plus supporting theoretical understanding of both effects. Compared to uniform rotation and precession the lunar rotational variations are up to 1 km, while tidal variations are about 0.1 m. Analysis of the lunar variations in pole direction and rotation about the pole gives moment of inertia differences, third-degree gravity harmonics, tidal Love number k2, tidal dissipation Q vs. frequency, dissipation at the fluid-core/solid-mantle boundary, and emerging evidence for an oblate boundary. The last two indicate a fluid core, but a solid inner core is not ruled out. Four retroreflectors provide very accurate positions on the Moon. The experience with the Moon is a starting point for exploring the tides, rotation and orientation of the other synchronous bodies of the solar system.

Firefly: A HOT camera core for thermal imagers with enhanced functionality

NASA Astrophysics Data System (ADS)

Pillans, Luke; Harmer, Jack; Edwards, Tim

2015-06-01

Raising the operating temperature of mercury cadmium telluride infrared detectors from 80K to above 160K creates new applications for high performance infrared imagers by vastly reducing the size, weight and power consumption of the integrated cryogenic cooler. Realizing the benefits of Higher Operating Temperature (HOT) requires a new kind of infrared camera core with the flexibility to address emerging applications in handheld, weapon mounted and UAV markets. This paper discusses the Firefly core developed to address these needs by Selex ES in Southampton UK. Firefly represents a fundamental redesign of the infrared signal chain reducing power consumption and providing compatibility with low cost, low power Commercial Off-The-Shelf (COTS) computing technology. This paper describes key innovations in this signal chain: a ROIC purpose built to minimize power consumption in the proximity electronics, GPU based image processing of infrared video, and a software customisable infrared core which can communicate wirelessly with other Battlespace systems.

Insights into Mercury's interior structure from geodesy measurements

NASA Astrophysics Data System (ADS)

Rivoldini, A.; Van Hoolst, T.; Trinh, A.

2013-09-01

The measurements of the gravitational field of Mercury by MESSENGER [1] and improved measurements of the spin state of Mercury [2] provide important constraints on the interior structure of Mercury. In particular, these data give strong constraints on the radius and density of Mercury's core and on the core's concentration of sulfur if sulfur is the only light element in the core [3]. Although sulfur is ubiquitously invoked as being the principal candidate light element in terrestrial planet's cores its abundance in the core depends on the redox conditions during planetary formation. MESSENGER data from remote sensing of Mercury's surface [4] indicate a high abundance of sulfur and confirm the low abundance in FeO supporting the hypotheses that Mercury formed under reducing conditions [5]. Therefore, substantial amounts of other light elements like for instance silicon could be present together with sulfur inside Mercury's core. Unlike sulfur, which does almost not partition into solid iron under Mercury's core pressure and temperature conditions, silicon partitions virtually equally between solid and liquid iron. Thus, if silicon is the only light element inside the core, the density jump at the inner-core outer-core boundary is significantly smaller if compared to an Fe - FeS core. If both silicon and sulfur are present inside Mercury's core then as a consequence of a large immiscibility region in liquid Fe - Si - S at Mercury's core conditions and for specific concentrations of light elements [6] a thin layer much enriched in sulfur and depleted in silicon could form at the top of the core. In this study we analyze interior structure models with silicon as the only light element in the core and with both silicon and sulfur in the core. Compared to models with Fe - FeS both settings have different mass distributions within their cores and will likely deform differently due to different elastic properties. Consequently their libration and tides will be different. Here we will use the measured 88 day libration amplitude and polar moment of inertia of Mercury in order to constrain the interior structure of both settings and calculate their tides.

KSC-2011-2448

NASA Image and Video Library

2011-03-23

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., test the electrical continuity of a solar array, left, that will help power NASA's Juno spacecraft on a mission to Jupiter. Two other arrays are in work stands on the right. Power-generating panels on three sets of solar arrays will extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet in order to operate at such a great distance from the sun. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

RGB-Stack Light Emitting Diode Modules with Transparent Glass Circuit Board and Oil Encapsulation

PubMed Central

Li, Ying-Chang; Chang, Yuan-Hsiao; Singh, Preetpal; Chang, Liann-Be; Yeh, Der-Hwa; Chao, Ting-Yu; Jian, Si-Yun; Li, Yu-Chi; Lai, Chao-Sung; Ying, Shang-Ping

2018-01-01

The light emitting diode (LED) is widely used in modern solid-state lighting applications, and its output efficiency is closely related to the submounts’ material properties. Most submounts used today, such as low-power printed circuit boards (PCBs) or high-power metal core printed circuit boards (MCPCBs), are not transparent and seriously decrease the output light extraction. To meet the requirements of high light output and better color mixing, a three-dimensional (3-D) stacked flip-chip (FC) LED module is proposed and demonstrated. To realize light penetration and mixing, the mentioned 3-D vertically stacking RGB LEDs use transparent glass as FC package submounts called glass circuit boards (GCB). Light emitted from each GCB stacked LEDs passes through each other and thus exhibits good output efficiency and homogeneous light-mixing characteristics. In this work, the parasitic problem of heat accumulation, which caused by the poor thermal conductivity of GCB and leads to a serious decrease in output efficiency, is solved by a proposed transparent cooling oil encapsulation (OCP) method. PMID:29494534

RGB-Stack Light Emitting Diode Modules with Transparent Glass Circuit Board and Oil Encapsulation.

PubMed

Li, Ying-Chang; Chang, Yuan-Hsiao; Singh, Preetpal; Chang, Liann-Be; Yeh, Der-Hwa; Chao, Ting-Yu; Jian, Si-Yun; Li, Yu-Chi; Tan, Cher Ming; Lai, Chao-Sung; Chow, Lee; Ying, Shang-Ping

2018-03-01

The light emitting diode (LED) is widely used in modern solid-state lighting applications, and its output efficiency is closely related to the submounts' material properties. Most submounts used today, such as low-power printed circuit boards (PCBs) or high-power metal core printed circuit boards (MCPCBs), are not transparent and seriously decrease the output light extraction. To meet the requirements of high light output and better color mixing, a three-dimensional (3-D) stacked flip-chip (FC) LED module is proposed and demonstrated. To realize light penetration and mixing, the mentioned 3-D vertically stacking RGB LEDs use transparent glass as FC package submounts called glass circuit boards (GCB). Light emitted from each GCB stacked LEDs passes through each other and thus exhibits good output efficiency and homogeneous light-mixing characteristics. In this work, the parasitic problem of heat accumulation, which caused by the poor thermal conductivity of GCB and leads to a serious decrease in output efficiency, is solved by a proposed transparent cooling oil encapsulation (OCP) method.

Gas Lasers

NASA Astrophysics Data System (ADS)

Dixit, S. K.

The field of gas lasers, started with the invention of He-Ne laser in 1961, has witnessed tremendous growth in terms of technology development, research into gaseous gain medium, resonator physics and application in widely diverse arenas. This was possible due to high versatility of gas lasers in terms of operating wavelengths, power, beam quality and mode of operation. In recent years, there is a definite trend to replace the gas lasers, wherever possible, by more efficient and compact solid-state lasers. However, for many industrial, medical and military applications, the gas lasers still rule the roost due to their high-power capabilities with good beam quality at specific wavelengths. This chapter presents a short review covering the operating principle, important technical details and application potential of all the important gas lasers such as He-Ne, CO2, argon ion, copper vapour, excimer and chemical lasers. These neutral atoms, ions and molecule gas lasers are discussed as per applicable electrical, chemical and optical excitation schemes. The optically pumped gas lasers, recently experiencing resurgence, are discussed in the context of far infrared THz molecular lasers, diode-pumped alkali lasers and optically pumped gas-filled hollow-core fibre lasers.

Field-Reversed Configuration Power Plant Critical-Issue Scoping Study

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

Santarius, J. F.; Mogahed, E. A.; Emmert, G. A.

A team from the Universities of Wisconsin, Washington, and Illinois performed an engineering scoping study of critical issues for field-reversed configuration (FRC) power plants. The key tasks for this research were (1) systems analysis for deuterium-tritium (D-T) FRC fusion power plants, and (2) conceptual design of the blanket and shield module for an FRC fusion core. For the engineering conceptual design of the fusion core, the project team focused on intermediate-term technology. For example, one decision was to use steele structure. The FRC systems analysis led to a fusion power plant with attractive features including modest size, cylindrical symmetry, goodmore » thermal efficiency (52%), relatively easy maintenance, and a high ratio of electric power to fusion core mass, indicating that it would have favorable economics.« less

Core-Noise

NASA Technical Reports Server (NTRS)

Hultgren, Lennart S.

2010-01-01

This presentation is a technical progress report and near-term outlook for NASA-internal and NASA-sponsored external work on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system level noise metrics for the 2015, 2020, and 2025 timeframes; the emerging importance of core noise and its relevance to the SFW Reduced-Noise-Aircraft Technical Challenge; the current research activities in the core-noise area, with some additional details given about the development of a high-fidelity combustion-noise prediction capability; the need for a core-noise diagnostic capability to generate benchmark data for validation of both high-fidelity work and improved models, as well as testing of future noise-reduction technologies; relevant existing core-noise tests using real engines and auxiliary power units; and examples of possible scenarios for a future diagnostic facility. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Noise-Aircraft Technical Challenge aims to enable concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical for enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor designs could increase the combustion-noise component. The trend towards high-power-density cores also means that the noise generated in the low-pressure turbine will likely increase. Consequently, the combined result from these emerging changes will be to elevate the overall importance of turbomachinery core noise, which will need to be addressed in order to meet future noise goals.

Reactor core isolation cooling system

DOEpatents

Cooke, F.E.

1992-12-08

A reactor core isolation cooling system includes a reactor pressure vessel containing a reactor core, a drywell vessel, a containment vessel, and an isolation pool containing an isolation condenser. A turbine is operatively joined to the pressure vessel outlet steamline and powers a pump operatively joined to the pressure vessel feedwater line. In operation, steam from the pressure vessel powers the turbine which in turn powers the pump to pump makeup water from a pool to the feedwater line into the pressure vessel for maintaining water level over the reactor core. Steam discharged from the turbine is channeled to the isolation condenser and is condensed therein. The resulting heat is discharged into the isolation pool and vented to the atmosphere outside the containment vessel for removing heat therefrom. 1 figure.

Reactor core isolation cooling system

DOEpatents

Cooke, Franklin E.

1992-01-01

A reactor core isolation cooling system includes a reactor pressure vessel containing a reactor core, a drywell vessel, a containment vessel, and an isolation pool containing an isolation condenser. A turbine is operatively joined to the pressure vessel outlet steamline and powers a pump operatively joined to the pressure vessel feedwater line. In operation, steam from the pressure vessel powers the turbine which in turn powers the pump to pump makeup water from a pool to the feedwater line into the pressure vessel for maintaining water level over the reactor core. Steam discharged from the turbine is channeled to the isolation condenser and is condensed therein. The resulting heat is discharged into the isolation pool and vented to the atmosphere outside the containment vessel for removing heat therefrom.

Synthesis of fluorescent core-shell nanomaterials and strategies to generate white light

NASA Astrophysics Data System (ADS)

Singh, Amandeep; Kaur, Ramanjot; Pandey, O. P.; Wei, Xueyong; Sharma, Manoj

2015-07-01

In this work, cadmium free core-shell ZnS:X/ZnS (X = Mn, Cu) nanoparticles have been synthesized and used for white light generation. First, the doping concentration of Manganese (Mn) was varied from 1% to 4% to optimize the dopant related emission and its optimal value was found to be 1%. Then, ZnS shell was grown over ZnS:Mn(1%) core to passivate the surface defects. Similarly, the optimal concentration of Copper (Cu) was found to be 0.8% in the range varied from 0.6% to 1.2%. In order to obtain an emission in the whole visible spectrum, dual doping of Mn and Cu was done in the core and the shell, respectively. A solid-solid mixing in different ratios of separately doped quantum dots (QDs) emitting in the blue green and the orange region was performed. Results show that the optimum mixture of QDs excited at 300 nm gives Commission Internationale del'Éclairage color coordinates of (0.35, 0.36), high color rendering index of 88, and correlated color temperature of 4704 K with minimum self-absorption.

Solid state, S-band, power amplifier

NASA Technical Reports Server (NTRS)

Digrindakis, M.

1973-01-01

The final design and specifications for a solid state, S-band, power amplifier is reported. Modifications from a previously proposed design were incorporated to improve efficiency and meet input overdrive and noise floor requirements. Reports on the system design, driver amplifier, power amplifier, and voltage and current limiter are included along with a discussion of the testing program.

Mirror fusion propulsion system: A performance comparison with alternate propulsion systems for the manned Mars Mission

NASA Technical Reports Server (NTRS)

Schulze, Norman R.; Carpenter, Scott A.; Deveny, Marc E.; Oconnell, T.

1993-01-01

The performance characteristics of several propulsion technologies applied to piloted Mars missions are compared. The characteristics that are compared are Initial Mass in Low Earth Orbit (IMLEO), mission flexibility, and flight times. The propulsion systems being compared are both demonstrated and envisioned: Chemical (or Cryogenic), Nuclear Thermal Rocket (NTR) solid core, NTR gas core, Nuclear Electric Propulsion (NEP), and a mirror fusion space propulsion system. The proposed magnetic mirror fusion reactor, known as the Mirror Fusion Propulsion System (MFPS), is described. The description is an overview of a design study that was conducted to convert a mirror reactor experiment at Lawrence Livermore National Lab (LLNL) into a viable space propulsion system. Design principles geared towards minimizing mass and maximizing power available for thrust are identified and applied to the LLNL reactor design, resulting in the MFPS. The MFPS' design evolution, reactor and fuel choices, and system configuration are described. Results of the performance comparison shows that the MFPS minimizes flight time to 60 to 90 days for flights to Mars while allowing continuous return-home capability while at Mars. Total MFPS IMLEO including propellant and payloads is kept to about 1,000 metric tons.

Phytoscreening with SPME: Variability Analysis.

PubMed

Limmer, Matt A; Burken, Joel G

2015-01-01

Phytoscreening has been demonstrated at a variety of sites over the past 15 years as a low-impact, sustainable tool in delineation of shallow groundwater contaminated with chlorinated solvents. Collection of tree cores is rapid and straightforward, but low concentrations in tree tissues requires sensitive analytics. Solid-phase microextraction (SPME) is amenable to the complex matrix while allowing for solvent-less extraction. Accurate quantification requires the absence of competitive sorption, examined here both in laboratory experiments and through comprehensive examination of field data. Analysis of approximately 2,000 trees at numerous field sites also allowed testing of the tree genus and diameter effects on measured tree contaminant concentrations. Collectively, while these variables were found to significantly affect site-adjusted perchloroethylene (PCE) concentrations, the explanatory power of these effects was small (adjusted R(2) = 0.031). 90th quantile chemical concentrations in trees were significantly reduced by increasing Henry's constant and increasing hydrophobicity. Analysis of replicate tree core data showed no correlation between replicate relative standard deviation (RSD) and wood type or tree diameter, with an overall median RSD of 30%. Collectively, these findings indicate SPME is an appropriate technique for sampling and analyzing chlorinated solvents in wood and that phytoscreening is robust against changes in tree type and diameter.

Mirror fusion propulsion system - A performance comparison with alternate propulsion systems for the manned Mars mission

NASA Technical Reports Server (NTRS)

Deveny, M.; Carpenter, S.; O'Connell, T.; Schulze, N.

1993-01-01

The performance characteristics of several propulsion technologies applied to piloted Mars missions are compared. The characteristics that are compared are Initial Mass in Low Earth Orbit (IMLEO), mission flexibility, and flight times. The propulsion systems being compared are both demonstrated and envisioned: Chemical (or Cryogenic), Nuclear Thermal Rocket (NTR) solid core, NTR gas core, Nuclear Electric Propulsion (NEP), and a mirror fusion space propulsion system. The proposed magnetic mirror fusion reactor, known as the Mirror Fusion Propulsion System (MFPS), is described. The description is an overview of a design study that was conducted to convert a mirror reactor experiment at Lawrence Livermore National Lab (LLNL) into a viable space propulsion system. Design principles geared towards minimizing mass and maximizing power available for thrust are identified and applied to the LLNL reactor design, resulting in the MFPS. The MFPS' design evolution, reactor and fuel choices, and system configuration are described. Results of the performance comparison shows that the MFPS minimizes flight time to 60 to 90 days for flights to Mars while allowing continuous return-home capability while at Mars. Total MFPS IMLEO including propellant and payloads is kept to about 1,000 metric tons.

Nuclear thermal propulsion engine system design analysis code development

NASA Astrophysics Data System (ADS)

Pelaccio, Dennis G.; Scheil, Christine M.; Petrosky, Lyman J.; Ivanenok, Joseph F.

1992-01-01

A Nuclear Thermal Propulsion (NTP) Engine System Design Analyis Code has recently been developed to characterize key NTP engine system design features. Such a versatile, standalone NTP system performance and engine design code is required to support ongoing and future engine system and vehicle design efforts associated with proposed Space Exploration Initiative (SEI) missions of interest. Key areas of interest in the engine system modeling effort were the reactor, shielding, and inclusion of an engine multi-redundant propellant pump feed system design option. A solid-core nuclear thermal reactor and internal shielding code model was developed to estimate the reactor's thermal-hydraulic and physical parameters based on a prescribed thermal output which was integrated into a state-of-the-art engine system design model. The reactor code module has the capability to model graphite, composite, or carbide fuels. Key output from the model consists of reactor parameters such as thermal power, pressure drop, thermal profile, and heat generation in cooled structures (reflector, shield, and core supports), as well as the engine system parameters such as weight, dimensions, pressures, temperatures, mass flows, and performance. The model's overall analysis methodology and its key assumptions and capabilities are summarized in this paper.

Calcium oxide-modified mesoporous silica loaded onto ferriferrous oxide core: Magnetically responsive mesoporous solid strong base.

PubMed

Li, Tian-Tian; Liu, Yu; Qi, Shi-Chao; Liu, Xiao-Qin; Huang, Li; Sun, Lin-Bing

2018-05-03

The design of new type of solid strong base with ideal activity, stability, and reusability is strongly urged by the growing demand of green chemistry and sustainable development. In this study, a new type of mesoporous solid strong base, denoted as CaO/mSiO 2 /Fe 3 O 4 , is successfully fabricated by successively coating SiO 2 onto Fe 3 O 4 magnetic nanoparticles and loading CaO into the mesoporous SiO 2 . Compared with a series of other typical solid bases, the CaO/mSiO 2 /Fe 3 O 4 exhibits higher activity towards the synthesis of dimethyl carbonate by the transesterification of ethylene carbonate and methanol. The activity of the CaO/mSiO 2 /Fe 3 O 4 is not observed to decrease obviously even after sextic catalyst recirculation, and in particular, the recovery of the catalyst without quality loss is very convenient due to the good magnetic responsiveness of the Fe 3 O 4 cores. Copyright © 2018. Published by Elsevier Inc.

Lasers for industrial production processing: tailored tools with increasing flexibility

NASA Astrophysics Data System (ADS)

Rath, Wolfram

2012-03-01

High-power fiber lasers are the newest generation of diode-pumped solid-state lasers. Due to their all-fiber design they are compact, efficient and robust. Rofin's Fiber lasers are available with highest beam qualities but the use of different process fiber core sizes enables the user additionally to adapt the beam quality, focus size and Rayleigh length to his requirements for best processing results. Multi-mode fibers from 50μm to 600μm with corresponding beam qualities of 2.5 mm.mrad to 25 mm.mrad are typically used. The integrated beam switching modules can make the laser power available to 4 different manufacturing systems or can share the power to two processing heads for parallel processing. Also CO2 Slab lasers combine high power with either "single-mode" beam quality or higher order modes. The wellestablished technique is in use for a large number of industrial applications, processing either metals or non-metallic materials. For many of these applications CO2 lasers remain the best choice of possible laser sources either driven by the specific requirements of the application or because of the cost structure of the application. The actual technical properties of these lasers will be presented including an overview over the wavelength driven differences of application results, examples of current industrial practice as cutting, welding, surface processing including the flexible use of scanners and classical optics processing heads.

Density functional description of size-dependent effects at nucleation on neutral and charged nanoparticles

NASA Astrophysics Data System (ADS)

Shchekin, Alexander K.; Lebedeva, Tatiana S.

2017-03-01

A numerical study of size-dependent effects in the thermodynamics of a small droplet formed around a solid nanoparticle has been performed within the square-gradient density functional theory. The Lennard-Jones fluid with the Carnahan-Starling model for the hard-sphere contribution to intermolecular interaction in liquid and vapor phases and interfaces has been used for description of the condensate. The intermolecular forces between the solid core and condensate molecules have been taken into account with the help of the Lennard-Jones part of the total molecular potential of the core. The influence of the electric charge of the particle has been considered under assumption of the central Coulomb potential in the medium with dielectric permittivity depending on local condensate density. The condensate density profiles and equimolecular radii for equilibrium droplets at different values of the condensate chemical potential have been computed in the cases of an uncharged solid core with the molecular potential, a charged core without molecular potential, and a core with joint action of the Coulomb and molecular potentials. The appearance of stable equilibrium droplets even in the absence of the electric charge has been commented. As a next step, the capillary, disjoining pressure, and electrostatic contributions to the condensate chemical potential have been considered and compared with the predictions of classical thermodynamics in a wide range of values of the droplet and the particle equimolecular radii. With the help of the found dependence of the condensate chemical potential in droplet on the droplet size, the activation barrier for nucleation on uncharged and charged particles has been computed as a function of the vapor supersaturation. Finally, the work of droplet formation and the work of wetting the particle have been found as functions of the droplet size.

Time-dependent heat transfer in the spherical Earth: Implications on the power and thermal evolution of the core

NASA Astrophysics Data System (ADS)

Hofmeister, A. M.; Criss, R. E.

2015-12-01

We quantitatively investigate the time-dependence of heat conduction for a post-core, spherical Earth that is not convecting, due to compositional layering, based on hundreds of measurements of thermal diffusivity (D) for insulators and metals. Consistency of our solutions for widely ranging input parameters indicates how additional heat transfer mechanisms (mantle magmatism and convection) affect thermal evolution of the core. We consider 1) interior starting temperatures (T) of 273-5000 K, which represent variations in primordial heat, 2) different distributions and decay of long-lived radioactive isotopes, 3) additional heat sources in the core (primordial or latent heat), and 4) variable depth-T dependence of D. Our new analytical solution for cooling of a constant D sphere validates our numerical results. The bottom line is that the thermally insulating nature of minerals, combined with constraints of spherical geometry, limits steep thermal gradients to the upper mantle, consistent with the short length scale (x ~700 km) of cooling over t = 4.5 Ga indicated by dimensional analysis [x2 ~ 4Dt], and with plate tectonics. Consequently, interior temperatures vary little so the core has remained hot and is possibly warming. Findings include: 1) Constant vs. variable D affects thermal profiles only in detail, with D for the metallic core being inconsequential. 2) The hottest zone in Earth may lie in the uppermost lower mantle; 3) Most radiogenic heat is released in Earth's outermost 1000 km thereby driving an active outer shell; 4) Earth's core is essentially isothermal and is thus best described by the liquid-solid phase boundary; 5) Deeply sequestered radioactivity or other heat will melt the core rather than by run the dynamo (note that the heat needed to have melted the outer core is 10% of radiogenic heat generated over Earth's history); 6) Inefficient cooling of an Earth-sized mass means that heat essentially remains where it is generated, until it is removed by magmatism; 7) Importantly, the observed plate velocities are consistent with a Nusselt number of 1, i.e. the present day cooling is essentially conductive. Conductive cooling plus magmatism largely governs Earth's thermal structure and dynamics, below a unicellular upper mantle. Core dynamics and magnetism are likely driven by rotational effects.

Flux harmonics in large SFR cores in relation with core characteristics such as power peaks

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

Rimpault, G.; Buiron, L.; Fontaine, B.

2013-07-01

Designing future Sodium Fast Reactors (SFR) requires enhancing their operational performance and reducing the probability to go into core disruption. As a consequence of these constraints, these novel reactors exhibit rather unusual features compared to past designs. The cores are much larger with rather flat shape. The consequences of that shape on the core characteristics deserve to be studied. The approach taken in this paper is to calculate the eigenvalue associated to the first harmonic and its associated flux. It is demonstrated that these values are linked to some core features, in particular, those sensitive to spatial effects such asmore » power peaks induced by the movement of control rods. The uncertainty associated to these characteristics is being tentatively studied and guidelines for further studied are being identified. In the development strategy of these new SFR designs, a first demonstration plant of limited installed power (around 1500 MWth) will have to be built first. Identifying the possibility of going later to higher power plants (around 3600 MWth) without facing new challenges is an important criterion for designing such a plant. That strategy is being studied, in this paper, focusing on some rather frequent initiator such as the inadvertent control rod withdrawal for different core sizes with the help of the perturbation theory and the flux harmonics. (authors)« less

Femtosecond solid-state laser based on a few-layered black phosphorus saturable absorber.

PubMed

Su, Xiancui; Wang, Yiran; Zhang, Baitao; Zhao, Ruwei; Yang, Kejian; He, Jingliang; Hu, Qiangqiang; Jia, Zhitai; Tao, Xutang

2016-05-01

In this Letter, a high-quality, few-layered black phosphorus (BP) saturable absorber (SA) was fabricated successfully, and a femtosecond solid-state laser modulated by BP-SA was experimentally demonstrated for the first time, to the best of our knowledge. Pulses as short as 272 fs were achieved with an average output power of 0.82 W, corresponding to the pulse energy of 6.48 nJ and peak power of 23.8 MW. So far, these represent the shortest pulse duration and highest output power ever obtained with a BP-based mode-locked solid-state laser. The results indicate the promising potential of few-layered BP-SA for applications in solid-state femtosecond mode-locked lasers.

Efficient Storing Energy Harvested by Triboelectric Nanogenerators Using a Safe and Durable All-Solid-State Sodium-Ion Battery.

PubMed

Hou, Huidan; Xu, Qingkai; Pang, Yaokun; Li, Lei; Wang, Jiulin; Zhang, Chi; Sun, Chunwen

2017-08-01

Storing energy harvested by triboelectric nanogenerators (TENGs) from ambient mechanical motion is still a great challenge for achieving low-cost and environmental benign power sources. Here, an all-solid-state Na-ion battery with safe and durable performance used for efficient storing pulsed energy harvested by the TENG is demonstrated. The solid-state sodium-ion batteries are charged by galvanostatic mode and pulse mode with the TENG, respectively. The all-solid-state sodium-ion battery displays excellent cyclic performance up to 1000 cycles with a capacity retention of about 85% even at a high charge and discharge current density of 48 mA g -1 . When charged by the TENG, an energy conversion efficiency of 62.3% is demonstrated. The integration of TENGs with the safe and durable all-solid-state sodium-ion batteries is potential for providing more stable power output for self-powered systems.

Highly efficient method for production of radioactive silver seed cores for brachytherapy.

PubMed

Cardoso, Roberta Mansini; de Souza, Carla Daruich; Rostelato, Maria Elisa Chuery Martins; Araki, Koiti

2017-02-01

A simple and highly efficient (shorter reaction time and almost no rework) method for production of iodine based radioactive silver seed cores for brachytherapy is described. The method allows almost quantitative deposition of iodine-131 on dozens of silver substrates at once, with even distribution of activity per core and insignificant amounts of liquid and solid radioactive wastes, allowing the fabrication of cheaper radioactive iodine seeds for brachytherapy. Copyright © 2016. Published by Elsevier Ltd.

Phosphate-core silica-clad Er/Yb-doped optical fiber and cladding pumped laser.

PubMed

Egorova, O N; Semjonov, S L; Velmiskin, V V; Yatsenko, Yu P; Sverchkov, S E; Galagan, B I; Denker, B I; Dianov, E M

2014-04-07

We present a composite optical fiber with a Er/Yb co-doped phosphate-glass core in a silica glass cladding as well as cladding pumped laser. The fabrication process, optical properties, and lasing parameters are described. The slope efficiency under 980 nm cladding pumping reached 39% with respect to the absorbed pump power and 28% with respect to the coupled pump power. Due to high doping level of the phosphate core optimal length was several times shorter than that of silica core fibers.

Core follow calculation with the nTRACER numerical reactor and verification using power reactor measurement data

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

Jung, Y. S.; Joo, H. G.; Yoon, J. I.

The nTRACER direct whole core transport code employing the planar MOC solution based 3-D calculation method, the subgroup method for resonance treatment, the Krylov matrix exponential method for depletion, and a subchannel thermal/hydraulic calculation solver was developed for practical high-fidelity simulation of power reactors. Its accuracy and performance is verified by comparing with the measurement data obtained for three pressurized water reactor cores. It is demonstrated that accurate and detailed multi-physic simulation of power reactors is practically realizable without any prior calculations or adjustments. (authors)

KSC-2011-2741

NASA Image and Video Library

2011-04-05

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., begin installing insulating blankets around the magnetometer boom. The boom structure is attached to Juno's solar array #1 that will help power the NASA spacecraft on its mission to Jupiter. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2743

NASA Image and Video Library

2011-04-05

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., install insulating blankets around the magnetometer boom. The boom structure is attached to Juno's solar array #1 that will help power the NASA spacecraft on its mission to Jupiter. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2746

NASA Image and Video Library

2011-04-05

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., prepare an insulating a blanket for installation onto the magnetometer boom. The boom structure is attached to Juno's solar array #1 that will help power the NASA spacecraft on its mission to Jupiter. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2744

NASA Image and Video Library

2011-04-05

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., install insulating blankets around the magnetometer boom. The boom structure is attached to Juno's solar array #1 that will help power the NASA spacecraft on its mission to Jupiter. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2742

NASA Image and Video Library

2011-04-05

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., begin installing insulating blankets around the magnetometer boom. The boom structure is attached to Juno's solar array #1 that will help power the NASA spacecraft on its mission to Jupiter. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2747

NASA Image and Video Library

2011-04-05

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., install insulating blankets around a magnetometer boom. The boom structure is attached to Juno's solar array #1 that will help power the NASA spacecraft on its mission to Jupiter. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-2749

NASA Image and Video Library

2011-04-05

CAPE CANAVERAL, Fla. -- Technicians in the Astrotech payload processing facility in Titusville, Fla., install insulating blankets around a magnetometer boom. The boom structure is attached to Juno's solar array #1 that will help power the NASA spacecraft on its mission to Jupiter. Juno is scheduled to launch aboard an Atlas V rocket from Cape Canaveral, Fla., on Aug. 5, 2011, reaching Jupiter in July 2016. The spacecraft will orbit the giant planet more than 30 times, skimming to within 3,000 miles above its cloud tops, for about one year. With its suite of science instruments, the spacecraft will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras. For more information visit, www.nasa.gov/juno. Photo credit: NASA/Jack Pfaller

KSC-2011-5979

NASA Image and Video Library

2011-07-25

CAPE CANAVERAL, Fla. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, a briefing was held to update media on the upcoming launch of NASA's Juno spacecraft. Seen here are Scott Bolton, Juno principal investigator with the Southwest Research Institute in San Antonio, Texas; Jan Chodas, Juno project manager with the Jet Propulsion Laboratory in Pasadena, Calif., and Kaelyn Badura, Pine Ridge High School, Deltona, Fla. high school student, Juno Education program participant and Goldstone Apple Valley Radio Telescope Project participant. Juno is scheduled to launch aboard an United Launch Alliance Atlas V from Cape Canaveral, Fla. Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Gianni M. Woods

KSC-2011-5978

NASA Image and Video Library

2011-07-25

CAPE CANAVERAL, Fla. -- In the Press Site auditorium at NASA's Kennedy Space Center in Florida, a briefing was held to update media on the upcoming launch of NASA's Juno spacecraft. Seen here are Scott Bolton, Juno principal investigator with the Southwest Research Institute in San Antonio, Texas; Jan Chodas, Juno project manager with the Jet Propulsion Laboratory in Pasadena, Calif., and Kaelyn Badura, Pine Ridge High School, Deltona, Fla. high school student, Juno Education program participant and Goldstone Apple Valley Radio Telescope Project participant. Juno is scheduled to launch aboard an United Launch Alliance Atlas V from Cape Canaveral, Fla. Aug. 5.The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information visit: www.nasa.gov/juno. Photo credit: NASA/Gianni M. Woods

KSC-2011-6055

NASA Image and Video Library

2011-07-27

CAPE CANAVERAL, Fla. -- At Space Launch Complex 41, the Atlas rocket stacked inside the Vertical Integration Facility stands ready to receive the Juno spacecraft, enclosed in an Atlas payload fairing. The spacecraft was prepared for launch in the Astrotech Space Operations' payload processing facility in Titusville, Fla. The fairing will protect the spacecraft from the impact of aerodynamic pressure and heating during ascent and will be jettisoned once the spacecraft is outside the Earth's atmosphere. Juno is scheduled to launch Aug. 5 aboard a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station in Florida. The solar-powered spacecraft will orbit Jupiter's poles 33 times to find out more about the gas giant's origins, structure, atmosphere and magnetosphere and investigate the existence of a solid planetary core. For more information, visit www.nasa.gov/juno. Photo credit: NASA/Cory Huston