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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

2011 Quantum Control of Light & Matter Gordon Research Conference (July 31-August 5, 2011, Mount Holyoke College, South Hadley, MA)

Quantum control of light and matter is the quest to steer a physical process to a desirable outcome, employing constructive and destructive interference. Three basic questions address feasibility of quantum control: (1) The problem of controllability, does a control field exist for a preset initial and target state; (2) Synthesis, constructively finding the field that leads to the target; and (3) Optimal Control Theory - optimizing the field that carries out this task. These continue to be the fundamental theoretical questions to be addressed in the conference. How to realize control fields in the laboratory is an ongoing challenge. This task is very diverse viewing the emergence of control scenarios ranging from attoseconds to microseconds. How do the experimental observations reflect on the theoretical framework? The typical arena of quantum control is an open environment where much of the control is indirect. How are control scenarios realized in dissipative open systems? Can new control opportunities emerge? Can one null decoherence effects? An ideal setting for control is ultracold matter. The initial and final state can be defined more precisely. Coherent control unifies many fields of physical science. A lesson learned in one field can reflect on another. Currently quantum information processing has emerged as a primary target of control where the key issue is controlling quantum gate operation. Modern nonlinear spectroscopy has emerged as another primary field. The challenge is to unravel the dynamics of molecular systems undergoing strong interactions with the environment. Quantum optics where non-classical fields are to be generated and employed. Finally, coherent control is the basis for quantum engineering. These issues will be under the limelight of the Gordon conference on Quantum Control of Light and Matter.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

PVA Based Ternary Nanocomposites with Enhanced Properties Prepared by Using a Combination of Rice Starch Nanocrystals and Silver Nanoparticles

Ternary nanocomposite films exhibiting better properties were prepared by incorporating two different nanoparticles such as rice starch nanocrystals (RSN) and silver nanoparticles (AgNPs) together in polyvinyl alcohol (PVA) matrix at various concentrations. The morphological evaluation using atomic force microscopy revealed that the particle size of RSN nanoparticles varied from 50 to 125 nm. The nanocomposite films made using these nanoparticles were evaluated for its chemical, mechanical and thermal properties. FTIR spectra of the films revealed some specific vibrational bands of RSN along with the characteristic bands of PVA. The mechanical property analysis of nanocomposite films indicated better tensile strength and elongation properties, which can be attributed to the strong interaction of PVA with RSN and AgNPs. The thermal properties of these films were also evaluated. These ternary nanocomposites exhibited superior mechanical properties, which is very much beneficial as far as the end use applications are concerned.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2011

Rational Design Synthesis and Evaluation of First Generation Inhibitors of the Giardia Lamblia Fructose-1 6-biphosphate Aldolase

Inhibitors of the Giardia lamblia fructose 1,6-bisphosphate aldolase (GlFBPA), which transforms fructose 1,6-bisphosphate (FBP) to dihydroxyacetone phosphate and glyceraldehyde 3-phosphate, were designed based on 3-hydroxy-2-pyridone and 1,2-dihydroxypyridine scaffolds that position two negatively charged tetrahedral groups for interaction with substrate phosphate binding residues, a hydrogen bond donor to the catalytic Asp83, and a Zn{sup 2+} binding group. The inhibition activities for the GlFBPA catalyzed reaction of FBP of the prepared alkyl phosphonate/phosphate substituted 3-hydroxy-2-pyridinones and a dihydroxypyridine were determined. The 3-hydroxy-2-pyridone inhibitor 8 was found to bind to GlFBPA with an affinity (K{sub i} = 14 {micro}M) that is comparable to that of FBP (K{sub m} = 2 {micro}M) or its inert analog TBP (K{sub i} = 1 {micro}M). The X-ray structure of the GlFBPA-inhibitor 8 complex (2.3 {angstrom}) shows that 8 binds to the active site in the manner predicted by in silico docking with the exception of coordination with Zn{sup 2+}. The observed distances and orientation of the pyridone ring O=C-C-OH relative to Zn{sup 2+} are not consistent with a strong interaction. To determine if Zn{sup 2+} coordination occurs in the GlFBPA-inhibitor 8 complex in solution, EXAFS spectra were measured. A four coordinate geometry comprised of the three enzyme histidine ligands and an oxygen atom from the pyridone ring O=C-C-OH was indicated. Analysis of the Zn{sup 2+} coordination geometries in recently reported structures of class II FBPAs suggests that strong Zn{sup 2+} coordination is reserved for the enediolate-like transition state, accounting for minimal contribution of Zn{sup 2+} coordination to binding of 8 to GlFBPA.

08 HYDROGEN↗
DOE OSTI2014

Superspin glassy behaviour of La{sub 0.7}Ca{sub 0.3}Mn{sub 0.85}Al{sub 0.15}O{sub 3} thin film

Here, we present the low temperature magnetic behaviour of epitaxial La{sub 0.7}Ca{sub 0.3}Mn{sub 0.85}Al{sub 0.15}O{sub 3} (LCMAO) thin film through a series of DC magnetic measurements. Overall behaviour inferred from the magnetization measurements indicate that the magnetic phases created due to Al doping induced inhomogeneous distribution of Mn{sup 3+} and Mn{sup 4+} ions and oxygen vacancies present in the system act like superspins, and the strong interaction among themselves results in the superspin glassy behaviour. Interactions among the superspins are marked by the aging and zero filed memory effects. The glassy magnetic phase in LCMAO is found to follow the hierarchical model of spin glasses.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2015

Nuclear matter in the early universe

Recently, extreme conditions have been obtained in ultra-relativistic heavy ion collisions at RHIC and at the Large Hadron collider. It is believed that these conditions are similar to the ones of the early Universe, in the time between 10{sup −6}s and 1s, approximately. In this work, the hadrons produced in this range of time will be studied, considering some aspects of the systems produced in the heavy-ion collisions. We will study a phase posterior to the phase transition (in fact it is believed to be a crossover) from the quark-gluon plasma, that is the hadronic phase of the Universe. We will show the model proposed in [1], considering the hadronic matter described by a relativistic model (similar to the Walecka model), considering particles described by quantum equations in a curved spacetime. This curvature is due to the mass and to the strong interactions that appears in the energy-momentum tensor. The set of the equations is proposed in the Robertson-Walker metric, and some approximate solutions are obtained.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2011

Charmless Hadronic B Decays at Belle and BaBar

I report on recent measurements from the Belle and BABAR collaborations on the decay of the B meson to hadronic final states without a charm quark. The study of the branching fractions and angular distributions of B meson decays to hadronic final states without a charm quark probes the dynamics of both the weak and strong interactions, and plays an important role in understanding CP Violation (CPV) in the quark sector. CP Violation at the B factories is described graphically by a triangle with sides formed from the CKM matrix elements V{sub qd}V*{sub qb} (q = u, c, t) and internal angles {alpha}, {beta} {gamma} (or {phi}{sub 2}, {phi}{sub 1}, {phi}{sub 3}). Discrepancies in the measured values of the sides and angles could be an indication of New Physics beyond the Standard Model (SM) due to enhanced branching fractions or modified CP asymmetries. The experimental measurements of branching fractions, CP asymmetries, polarization and phases (both weak and strong) can be compared to theoretical models based on, for example, QCD factorization, SU(3) symmetry and Lattice QCD.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2011

Morphological and Structural Changes During the Reduction and Reoxidation of CuO/CeO(2) and Ce(1-x)Cu(x)O(2) Nanocatalysts: In-situ Studies with Environmental TEM, XRD and XAS

We have studied the structural, morphological, and electronic properties of CuO/CeO{sub 2} and Ce{sub 1-x}Cu{sub x}O{sub 2} nanocatalysts during reduction/oxidation cycles using H{sub 2} and O{sub 2} as chemical probes. Time-resolved in situ characterization was performed by X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) as well as aberration-corrected environmental transmission electron microscopy (ETEM). We have found that both types of nanocatalysts reduce to a Cu/CeO{sub 2} biphase system with significant oxygen vacancies in CeO{sub 2}. Important variations are seen in the Cu particle size and metal dispersion depending on the initial state of the copper oxide-ceria systems. During subsequent in situ oxygen annealing, the Cu precipitated from the CuO/CeO{sub 2} system reoxidized to form CuO through a Cu{sub 2}O intermediate phase as expected. However, the Cu precipitated from the Ce{sub 0.8}Cu{sub 0.2}O{sub 2} solid solution behaved rather differently under oxidizing conditions, and neither oxidized to form CuO nor fully returned to a bulk Ce{sub 0.8}Cu{sub 0.2}O{sub 2} phase in solid solution. We found that {approx} 50% of the Cu returned to a Ce{sub 1-x}Cu{sub x}O{sub 2} solid solution, while the remainder was observed by in situ ETEM to form an amorphous copper oxide phase with a Cu oxidation state similar to Ce{sub 1-x}Cu{sub x}O{sub 2}, but with a local bonding environment similar to CuO. The behavior of the reduced Ce{sub 0.8}Cu{sub 0.2}O{sub 2} reflects strong interactions between Cu and the ceria matrix and illustrates the advantages of working with solid solutions of mixed oxides.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Three-body Förster resonance of a new type in Rydberg atoms

The three-body Förster resonances 3 × nP{sub 3/2}(|M|) →nS{sub 1/2} + (n + 1)S{sub 1/2} + nP{sub 3/2}(|M*|), controlled by a constant electric field, were realised earlier by the authors in an ensemble of several cold Rydberg Rb atoms. One of the drawbacks of such resonances for potential application in three-qubit quantum gates is the proximity of the two-body Förster resonance 2 × nP{sub 3/2} → nS{sub 1/2} + (n + 1)S{sub 1/2}, as well as the possibility of their implementation only for states with values of the principal quantum numbers n ⩽38. A three-body resonance of a new type, 3 × nP{sub 3/2} → nS{sub 1/2} + (n + 1)S{sub 1/2} + nP{sub 1/2}, which can be realised for arbitrary n, is proposed and analysed. Its specific feature is also that the third atom transits into a state with a different total angular momentum J = 1/2, which has no Stark structure, so that the two-body resonance is completely absent. Numerical calculations showed that for not too strong interaction, it is possible to observe coherent three-body oscillations of the populations of collective states, which is of interest for developing new schemes of three-qubit quantum gates controlled by an electric field. (paper)

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2012

Quark-gluon plasma (Selected Topics)

Introductory lectures to the theory of (strongly interacting) quark-gluon plasma given at the Winter School of Physics of ITEP (Moscow, February 2010). We emphasize theoretical issues highlighted by the discovery of the low viscosity of the plasma. The topics include relativistic hydrodynamics, manifestations of chiral anomaly in hydrodynamics, superfluidity, relativistic superfluid hydrodynamics, effective stringy scalars, holographic models of Yang-Mills theories.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

Electronic Excitation Energy Transfer in an Array of CdS Quantum Dots on a Quasi-Two-Dimensional Surface

The optical spectra of films composed of spherical silicon-dioxide particles coated with small-radius CdS quantum dots are recorded and analyzed. Large shifts of the absorption and photoluminescence bands are detected and studied in relation to the concentration of quantum dots and to the pumping density and wavelength. Analysis of the experimental data shows that the effects are due to electronic excitation energy transfer by particles through the mechanism of tunneling induced by a strong interaction between quantum dots. The results obtained at low pumping densities and different excitation wavelengths make it possible to describe the size distribution of CdS quantum dots. This distribution can be adequately approximated with a Gaussian function.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2012

The Jefferson Lab program: From 6 GeV operations to the 12 GeV upgrade

The Thomas Jefferson National Laboratory and the CEBAF accelerator operated for more than a decade, running a comprehensive scientific program that improved our understanding of the strong interaction. The facility is now moving toward an upgrade of the machine, from 6 to 12 GeV; a new experimental hall will be added and the equipment of the three existing halls will be enhanced. In this contribution some selected results from the rich physics program run at JLab, as well as the prospects for the near future, will be presented.

43 PARTICLE ACCELERATORS↗
DOE OSTI2017

Transition Energies and Absorption Oscillator Strengths for c{sub 4}{sup ′1}Σ{sub u}{sup +}−X{sup 1}Σ{sub g}{sup +}, b{sup ′1}Σ{sub u}{sup +}−X{sup 1}Σ{sub g}{sup +}, and c{sub 5}{sup ′1}Σ{sub u}{sup +}−X{sup 1}Σ{sub g}{sup +} Band Systems in N{sub 2}

Theoretical transition energies and absorption oscillator strengths for the c{sub 4}{sup ′1}Σ{sub u}{sup +} (v′ = 0–2, 5, 7, 8) − X{sup 1}Σ{sub g}{sup +}(v{sup ′′}=0--14) and c{sub 5}{sup ′1}Σ{sub u}{sup +} (v′ = 0, 2) − X{sup 1}Σ{sub g}{sup +} (v″ = 0–14) Rydberg bands, and b{sup ′1}Σ{sub u}{sup +} (v′ = 0–9, 11, 12, 14–19, 21, 22) − X{sup 1}Σ{sub g}{sup +} (v″ = 0–14) valence bands of molecular nitrogen are reported. The strong interaction between {sup 1}Σ{sub u}{sup +} states has been dealt with through a vibronic interaction matrix. As a consequence of the Rydberg-valence interaction, irregularities in the vibrational structure of the above band systems are observed. Good agreement is found with the scarce high-resolution data that are available for oscillator strengths. The new band oscillator strengths reported here may be useful for a reliable interpretation of the spectra from atmospheres of the Earth, Titan, and Triton, where N{sub 2} is the mayor constituent.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2011

MIGRATION OF GAS GIANT PLANETS IN GRAVITATIONALLY UNSTABLE DISKS

Characterization of migration in gravitationally unstable disks is necessary to understand the fate of protoplanets formed by disk instability. As part of a larger study, we are using a three-dimensional radiative hydrodynamics code to investigate how an embedded gas giant planet interacts with a gas disk that undergoes gravitational instabilities (GIs). This Letter presents results from simulations with a Jupiter-mass planet placed in orbit at 25 AU within a 0.14 M{sub sun} disk. The disk spans 5-40 AU around a 1 M{sub sun} star and is initially marginally unstable. In one simulation, the planet is inserted prior to the eruption of GIs; in another, it is inserted only after the disk has settled into a quasi-steady GI-active state, where heating by GIs roughly balances radiative cooling. When the planet is present from the beginning, its own wake stimulates growth of a particular global mode with which it strongly interacts, and the planet plunges inward 6 AU in about 10{sup 3} years. In both cases with embedded planets, there are times when the planet's radial motion is slow and varies in direction. At other times, when the planet appears to be interacting with strong spiral modes, migration both inward and outward can be relatively rapid, covering several AUs over hundreds of years. Migration in both cases appears to stall near the inner Lindblad resonance of a dominant low-order mode. Planet orbit eccentricities fluctuate rapidly between about 0.02 and 0.1 throughout the GI-active phases of the simulations.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2018

Microwave-assisted synthesis of well-shaped UiO-66-NH2 with high CO2 adsorption capacity

Highlights: • Well-shaped UiO-66-NH{sub 2} was prepared through microwave heating in a short time. • Addition of HAc improves crystallinity and CO{sub 2} adsorption capacity of the UiO-66-NH{sub 2}. • UiO-66-NH{sub 2} prepared by microwave heating shows a higher CO{sub 2}/N{sub 2} adsorption selectivity. - Abstract: In a detailed study, the influence of microwave irradiation, synthesis time and temperature, addition of acetic acid (HAc) as a modulator on the morphology, crystallinity and stability of UiO-66-NH{sub 2} is investigated to develop a reliable and reproducible strategy for the preparation of well-shaped UiO-66-NH{sub 2}. The UiO-66-NH{sub 2} were characterized by powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), and gas adsorption. It is found that well-shaped UiO-66-NH{sub 2} with a high CO{sub 2} adsorption capacity can be synthesized in a short time by microwave heating. The UiO-66-NH{sub 2} crystals synthesized by microwave heating are of high quality and show a superior CO{sub 2} adsorption capacity (5.8 mmol/g at 273k and 1 bar) due to the strong interactions between the −NH{sub 2} group and CO{sub 2}. The CO{sub 2}/N{sub 2} selectivity of the obtained UiO-66-NH{sub 2} at 298 K and 1 bar is 66, which is much higher than that of the pristine UiO-66 of 17.8.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2011

Minimal composite inflation

We investigate models in which the inflaton emerges as a composite field of a four dimensional, strongly interacting and nonsupersymmetric gauge theory featuring only fermionic matter. We show that it is possible to obtain successful inflation via non-minimal coupling to gravity, and that the underlying dynamics is preferred to be near conformal. We discover that the compositeness scale of inflation is of the order of the grand unified energy scale.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Electrically tuned hyperfine spectrum in neutral Tb( II )(Cp iPr5 ) 2 single-molecule magnet

Molecular spin qubits with long spin coherence time as well as non-invasive operation methods on such qubits are in high demand. It was shown that both molecular electronic and nuclear spin levels can be used as qubits. In solid state systems with dopants, an electric field was shown to effectively change the spacing between the nuclear spin qubit levels when the electron spin density is high at the nucleus of the dopant. Inspired by such solid-state systems, we propose that divalent lanthanide (Ln) complexes with an unusual electronic configuration of Ln 2+ have a strong interaction between the Ln nuclear spin and the electronic degrees of freedom, which renders electrical tuning of the interaction. Furthermore, as an example, we study electronic structure and hyperfine interaction of the 159 Tb nucleus in a neutral Tb(II)(Cp iPr5 ) 2 single-molecule magnet (SMM), which exhibits unusually long magnetization relaxation time, using the complete active space self-consistent field (CASSCF) method with spin–orbit interaction included within the restricted active space state interaction (RASSI). Our calculations show that the low-energy states arise from 4f 8 (6s,5d z 2 ) 1 , 4f 8 (5d x 2 -y 2 ) 1 , and 4f 8 (5d xy ) 1 configurations. We compute the hyperfine interaction parameters and the electronic–nuclear spectrum within our multiconfigurational approach. We find that the hyperfine interaction is about one order of magnitude greater than that for Tb(III)Pc 2 SMMs. This stems from the strong Fermi contact interaction between the Tb nuclear spin and the electron spin density at the nucleus that originates from the occupation of the (6s,5d) orbitals. We also uncover that the response of the Fermi contact term to electric field results in electrical tuning of the electronic–nuclear level separations. This hyperfine Stark effect may be useful for applications of molecular nuclear spins for quantum computing.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2017

Tensor observables in electro- and photoreactions on the deuteron

The study of polarization effects in reactions with a simplest nucleus, deuteron, plays an important role for the investigation of deuteron structure as well as for the research of the properties of the strong interaction. However, data on the tensor observables in the electro- and photoreactions with deuteron appeared not so long ago. We present here a brief overview of the experiments on three such reactions with a deuteron: elastic scattering, photodisintegration and coherent photoproduction of the neutral pion.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2012

Status and plans of the NA61/SHINE physics program

One of the NA61/SHINE experiment's goals is to discover the critical point of strongly interacting matter and study the properties of the onset of deconfinement. This is to be achieved by performing a two-dimensional phase diagram (T- Micro-Sign {sub B}) scan-measuring hadron production in collisions of various beam particles and targets at various beam energies. NA61/SHINE also collects data for the T2K experiment, which are just about to be published.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗